Introduce the Counter character device interface
Subsystems (11)
v13 cover Introduce the Counter character device interface
Changes in v13:
- Use GFP_KERNEL when using mutexes instead of spinlocks
- Free event_node on error in counter_set_event_node
- Create n_events_list_lock mutex for protecting next_events_list access
- Adjust counter_set_event_node() locking to cover watch_validate() too
- Pull out COUNTER_ENABLE_EVENTS_IOCTL code into its own function counter_enable_events()
- Reimplement chrdev_lock as a bitmap and utilize test_and_set_bit_lock()/clear_bit_unlock() to handle locking
- Move wake_up_poll() call to after spin_unlock_irqrestore() in the counter_push_event() function
- Drop the lock on error in counter_events_queue_size_write()
- Rename "group" to "cattr_group" where appropriate for clarity
- Pull allocation of attribute groups to outside of for-loop in counter_sysfs_add()
- Define and use enum translation function st32_lptim_func_map()
- Provide complete example in enum counter_component documentation
- Provide inline description comments for enum counter_event_type
- Move documentation of Counter ioctl commands inline with code and reference them using :c:macro: in generic-counter.rst
- Make it clear which callbacks are optional in struct counter_ops
- Use HTML tables in Documentation/driver-api/generic-counter.rst
- Qualify struct counter_watch watches as statin in counter_example.c
- Return 1 on read() error in counter_example.c
- Remove unnecessary explicit casts in counter_example.c
For convenience, this patchset is also available on my personal git
repo: https://gitlab.com/vilhelmgray/iio/-/tree/counter_chrdev_v13
The patches preceding "counter: Internalize sysfs interface code" are primarily cleanup and fixes that can be picked up and applied now to the IIO tree if so desired. The "counter: Internalize sysfs interface code" patch as well may be considered for pickup because it is relatively safe and makes no changes to the userspace interface.
To summarize the main points of this patchset: there are no changes to the existing Counter sysfs userspace interface; a Counter character device interface is introduced that allows Counter events and associated data to be read() by userspace; the events_configure() and watch_validate() driver callbacks are introduced to support Counter events; and IRQ support is added to the 104-QUAD-8 driver, serving as an example of how to support the new Counter events functionality.
I did discover an issue with the character device code that I'm having trouble understanding. The issue does not affect the sysfs interface code so it's still safe to merge up to patch 08/17; only the character device node is affected starting with patch 10/17.
Suppose I open the chrdev from a userspace application and keep it open, but then remove the respective driver and Counter subsystem module from my system. The devm_counter_release() and counter_exit() functions will be called as expected; the counter_chrdev_release() function will not be called yet, but that is expected because the chrdev is still open by userspace. If I try to break out of my userspace application, I expect counter_chrdev_release() to finally be called, but this does not happen. Instead, my userspace application stalls and I see the following error in my dmesg:
[ 172.859570] BUG: unable to handle page fault for address: ffffffffc09ae298 [ 172.859594] #PF: supervisor read access in kernel mode [ 172.859598] #PF: error_code(0x0000) - not-present page [ 172.859603] PGD 23615067 P4D 23615067 PUD 23617067 PMD 1029ad067 PTE 0 [ 172.859623] Oops: 0000 [#1] SMP NOPTI [ 172.859629] CPU: 2 PID: 2485 Comm: counter_example Not tainted 5.13.0+ #1 [ 172.859640] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS d55cb5a 04/01/2014 [ 172.859645] RIP: 0010:filp_close+0x29/0x70 [ 172.859662] Code: 90 0f 1f 44 00 00 55 48 89 e5 41 56 41 55 41 54 48 8b 47 38 48 85 c0 0f 84 b7 40 86 00 48 8b 47 28 49 89 fc 49 89 f5 45 31 f6 <48> 8b 40 78 48 85 c0 74 08 ff d0 0f 1f 00 41 89 c6 41 f6 44 24 45 [ 172.859669] RSP: 0018:ffffad31c0ee7cb0 EFLAGS: 00010246 [ 172.859675] RAX: ffffffffc09ae220 RBX: 0000000000000001 RCX: 0000000000000001 [ 172.859680] RDX: ffff9a43829708e0 RSI: ffff9a4382970840 RDI: ffff9a43821f4f00 [ 172.859684] RBP: ffffad31c0ee7cc8 R08: 0000000000000001 R09: 0000000000000001 [ 172.859687] R10: ffffffffffff4d00 R11: ffff9a43933c6e10 R12: ffff9a43821f4f00 [ 172.859691] R13: ffff9a4382970840 R14: 0000000000000000 R15: 0000000000000003 [ 172.859694] FS: 0000000000000000(0000) GS:ffff9a44b7d00000(0000) knlGS:0000000000000000 [ 172.859699] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 172.859704] CR2: ffffffffc09ae298 CR3: 0000000023610001 CR4: 0000000000370ee0 [ 172.859713] Call Trace: [ 172.859730] put_files_struct+0x73/0xd0 [ 172.859738] exit_files+0x49/0x50 [ 172.859743] do_exit+0x33b/0xa20 [ 172.859751] do_group_exit+0x3b/0xb0 [ 172.859758] get_signal+0x16f/0x8b0 [ 172.859766] ? _copy_to_user+0x20/0x30 [ 172.859774] ? put_timespec64+0x3d/0x60 [ 172.859784] arch_do_signal_or_restart+0xf3/0x850 [ 172.859794] ? hrtimer_nanosleep+0x9f/0x120 [ 172.859802] ? __hrtimer_init+0xd0/0xd0 [ 172.859808] exit_to_user_mode_prepare+0x122/0x1b0 [ 172.859816] syscall_exit_to_user_mode+0x27/0x50 [ 172.859825] do_syscall_64+0x48/0xc0 [ 172.859831] entry_SYSCALL_64_after_hwframe+0x44/0xae [ 172.859839] RIP: 0033:0x7f07f8b9951a [ 172.859850] Code: Unable to access opcode bytes at RIP 0x7f07f8b994f0. [ 172.859853] RSP: 002b:00007ffc0d12c230 EFLAGS: 00000246 ORIG_RAX: 00000000000000e6 [ 172.859860] RAX: fffffffffffffdfc RBX: ffffffffffffff01 RCX: 00007f07f8b9951a [ 172.859863] RDX: 00007ffc0d12c2b0 RSI: 0000000000000000 RDI: 0000000000000000 [ 172.859867] RBP: 0000000000000000 R08: 0000000000000000 R09: 00007ffc0d12c1c6 [ 172.859871] R10: 00007ffc0d12c2b0 R11: 0000000000000246 R12: 00007ffc0d12c2b0 [ 172.859874] R13: 00007ffc0d12c2b0 R14: 0000000000000000 R15: 0000000000000000 [ 172.859886] Modules linked in: intel_rapl_msr intel_rapl_common kvm_intel kvm crct10dif_pclmul crc32_pclmul ghash_clmulni_intel nls_iso8859_1 aesni_intel crypto_simd cryptd rapl drm_ttm_helper ttm uvcvideo drm_kms_helper videobuf2_vmalloc videobuf2_memops videobuf2_v4l2 videobuf2_common input_leds syscopyarea videodev sysfillrect sysimgblt fb_sys_fops cec rc_core joydev mc drm serio_raw mac_hid qemu_fw_cfg sch_fq_codel msr parport_pc ppdev lp parport virtio_rng ip_tables x_tables autofs4 hid_generic usbhid hid virtio_net psmouse net_failover i2c_piix4 virtio_blk failover pata_acpi floppy [last unloaded: counter] [ 172.859995] CR2: ffffffffc09ae298 [ 172.860009] ---[ end trace e7d3d7da1a73b8f4 ]--- [ 172.860013] RIP: 0010:filp_close+0x29/0x70 [ 172.860021] Code: 90 0f 1f 44 00 00 55 48 89 e5 41 56 41 55 41 54 48 8b 47 38 48 85 c0 0f 84 b7 40 86 00 48 8b 47 28 49 89 fc 49 89 f5 45 31 f6 <48> 8b 40 78 48 85 c0 74 08 ff d0 0f 1f 00 41 89 c6 41 f6 44 24 45 [ 172.860027] RSP: 0018:ffffad31c0ee7cb0 EFLAGS: 00010246 [ 172.860031] RAX: ffffffffc09ae220 RBX: 0000000000000001 RCX: 0000000000000001 [ 172.860034] RDX: ffff9a43829708e0 RSI: ffff9a4382970840 RDI: ffff9a43821f4f00 [ 172.860038] RBP: ffffad31c0ee7cc8 R08: 0000000000000001 R09: 0000000000000001 [ 172.860041] R10: ffffffffffff4d00 R11: ffff9a43933c6e10 R12: ffff9a43821f4f00 [ 172.860044] R13: ffff9a4382970840 R14: 0000000000000000 R15: 0000000000000003 [ 172.860047] FS: 0000000000000000(0000) GS:ffff9a44b7d00000(0000) knlGS:0000000000000000 [ 172.860052] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 172.860056] CR2: ffffffffc09ae298 CR3: 0000000023610001 CR4: 0000000000370ee0 [ 172.860073] Fixing recursive fault but reboot is needed!
It looks like faults in filp_close() before counter_chrdev_release() is called. Is this issue manifesting because counter_exit() was called earlier while the chrdev was still open?
William Breathitt Gray (17):
counter: 104-quad-8: Return error when invalid mode during
ceiling_write
counter: Return error code on invalid modes
counter: Standardize to ERANGE for limit exceeded errors
counter: Rename counter_signal_value to counter_signal_level
counter: Rename counter_count_function to counter_function
counter: Internalize sysfs interface code
counter: Update counter.h comments to reflect sysfs internalization
docs: counter: Update to reflect sysfs internalization
counter: Move counter enums to uapi header
counter: Add character device interface
docs: counter: Document character device interface tools/counter: Create Counter tools
counter: Implement signalZ_action_component_id sysfs attribute
counter: Implement *_component_id sysfs attributes
counter: Implement events_queue_size sysfs attribute
counter: 104-quad-8: Replace mutex with spinlock
counter: 104-quad-8: Add IRQ support for the ACCES 104-QUAD-8
Documentation/ABI/testing/sysfs-bus-counter | 38 +- Documentation/driver-api/generic-counter.rst | 358 +++- .../userspace-api/ioctl/ioctl-number.rst | 1 + MAINTAINERS | 3 +- drivers/counter/104-quad-8.c | 728 ++++---- drivers/counter/Kconfig | 6 +- drivers/counter/Makefile | 1 + drivers/counter/counter-chrdev.c | 514 ++++++ drivers/counter/counter-chrdev.h | 14 + drivers/counter/counter-core.c | 182 ++ drivers/counter/counter-sysfs.c | 962 +++++++++++ drivers/counter/counter-sysfs.h | 13 + drivers/counter/counter.c | 1496 ----------------- drivers/counter/ftm-quaddec.c | 59 +- drivers/counter/intel-qep.c | 150 +- drivers/counter/interrupt-cnt.c | 73 +- drivers/counter/microchip-tcb-capture.c | 103 +- drivers/counter/stm32-lptimer-cnt.c | 211 ++- drivers/counter/stm32-timer-cnt.c | 147 +- drivers/counter/ti-eqep.c | 205 ++- include/linux/counter.h | 717 ++++---- include/linux/counter_enum.h | 45 - include/uapi/linux/counter.h | 154 ++ tools/Makefile | 13 +- tools/counter/Build | 1 + tools/counter/Makefile | 53 + tools/counter/counter_example.c | 93 + 27 files changed, 3572 insertions(+), 2768 deletions(-) create mode 100644 drivers/counter/counter-chrdev.c create mode 100644 drivers/counter/counter-chrdev.h create mode 100644 drivers/counter/counter-core.c create mode 100644 drivers/counter/counter-sysfs.c create mode 100644 drivers/counter/counter-sysfs.h delete mode 100644 drivers/counter/counter.c delete mode 100644 include/linux/counter_enum.h create mode 100644 include/uapi/linux/counter.h create mode 100644 tools/counter/Build create mode 100644 tools/counter/Makefile create mode 100644 tools/counter/counter_example.c
base-commit: 50be9417e23af5a8ac860d998e1e3f06b8fd79d7
Signature · 1 line
2.32.0
PATCH v13 1/17 counter: 104-quad-8: Return error when invalid mode during ceiling_write
The 104-QUAD-8 only has two count modes where a ceiling value makes
sense: Range Limit and Modulo-N. Outside of these two modes, setting a ceiling value is an invalid operation -- so let's report it as such by returning -EINVAL.
Fixes fc069262261c ("counter: 104-quad-8: Add lock guards - generic interface")
Signed-off-by William Breathitt Gray <[email protected]>
--- drivers/counter/104-quad-8.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-)
drivers/counter/104-quad-8.c +3 -2
@@ -715,12 +715,13 @@ static ssize_t quad8_count_ceiling_write(struct counter_device *counter,case 1 :case 3 :quad8_preset_register_set (priv, count->id, ceiling); -break ; +mutex_unlock (&priv->lock); +return len; }mutex_unlock (&priv->lock); -return len; +return -EINVAL ; } static ssize_t quad8_count_preset_enable_read(struct counter_device *counter,
Signature · 1 line
2.32.0
PATCH v13 2/17 counter: Return error code on invalid modes
In reply to William Breathitt GrayOnly a select set of modes (function, action, etc.) are valid for a given device configuration. This patch ensures that invalid modes result in a return -EINVAL. Such a situation should never occur in reality, but it's good to define a default switch case for the sake of making the intent of the code clear.
Cc Kamel Bouhara <[email protected]>
Cc Maxime Coquelin <[email protected]>
Cc Alexandre Torgue <[email protected]>
Acked-by David Lechner <[email protected]>
Reviewed-by Fabrice Gasnier <[email protected]>
Signed-off-by William Breathitt Gray <[email protected]>
--- drivers/counter/104-quad-8.c | 20 ++++++++++++------ drivers/counter/microchip-tcb-capture.c | 6 ++++++ drivers/counter/stm32-lptimer-cnt.c | 10 +++++---- drivers/counter/ti-eqep.c | 27 +++++++++++++++---------- 4 files changed, 42 insertions(+), 21 deletions(-)
drivers/counter/104-quad-8.c +14 -6
@@ -273,6 +273,10 @@ static int quad8_function_set(struct counter_device *counter, *scale =2 ; mode_cfg |=QUAD8_CMR_QUADRATURE_X4 ;break ; +default : +/* should never reach this path */ +mutex_unlock (&priv->lock); +return -EINVAL ; } }
@@ -349,7 +353,7 @@ static int quad8_action_get(struct counter_device *counter,case QUAD8_COUNT_FUNCTION_PULSE_DIRECTION :if (synapse->signal->id == signal_a_id) *action =QUAD8_SYNAPSE_ACTION_RISING_EDGE ; -break ; +return 0 ;case QUAD8_COUNT_FUNCTION_QUADRATURE_X1 :if (synapse->signal->id == signal_a_id) {quad8_direction_get (counter, count, &direction);
@@ -359,17 +363,18 @@ static int quad8_action_get(struct counter_device *counter,else *action =QUAD8_SYNAPSE_ACTION_FALLING_EDGE ; } -break ; +return 0 ;case QUAD8_COUNT_FUNCTION_QUADRATURE_X2 :if (synapse->signal->id == signal_a_id) *action =QUAD8_SYNAPSE_ACTION_BOTH_EDGES ; -break ; +return 0 ;case QUAD8_COUNT_FUNCTION_QUADRATURE_X4 : *action =QUAD8_SYNAPSE_ACTION_BOTH_EDGES ; -break ; +return 0 ; +default : +/* should never reach this path */ +return -EINVAL ; } - -return 0 ; }static const struct counter_ops quad8_ops = {
@@ -529,6 +534,9 @@ static int quad8_count_mode_set(struct counter_device *counter,case COUNTER_COUNT_MODE_MODULO_N : cnt_mode =3 ;break ; +default : +/* should never reach this path */ +return -EINVAL ; }mutex_lock (&priv->lock);
drivers/counter/microchip-tcb-capture.c +6 -0
@@ -133,6 +133,9 @@ static int mchp_tc_count_function_set(struct counter_device *counter, bmr |=ATMEL_TC_QDEN |ATMEL_TC_POSEN ; cmr |=ATMEL_TC_ETRGEDG_RISING |ATMEL_TC_ABETRG |ATMEL_TC_XC0 ;break ; +default : +/* should never reach this path */ +return -EINVAL ; }regmap_write (priv->regmap,ATMEL_TC_BMR , bmr);
@@ -226,6 +229,9 @@ static int mchp_tc_count_action_set(struct counter_device *counter,case MCHP_TC_SYNAPSE_ACTION_BOTH_EDGE : edge =ATMEL_TC_ETRGEDG_BOTH ;break ; +default : +/* should never reach this path */ +return -EINVAL ; } return regmap_write_bits(priv->regmap,
drivers/counter/stm32-lptimer-cnt.c +6 -4
@@ -206,9 +206,10 @@ static int stm32_lptim_cnt_function_set(struct counter_device *counter, priv->quadrature_mode =1 ; priv->polarity =STM32_LPTIM_SYNAPSE_ACTION_BOTH_EDGES ;return 0 ; +default : +/* should never reach this path */ +return -EINVAL ; } - -return -EINVAL ; } static ssize_t stm32_lptim_cnt_enable_read(struct counter_device *counter,
@@ -326,9 +327,10 @@ static int stm32_lptim_cnt_action_get(struct counter_device *counter,case STM32_LPTIM_ENCODER_BOTH_EDGE : *action = priv->polarity;return 0 ; +default : +/* should never reach this path */ +return -EINVAL ; } - -return -EINVAL ; } static int stm32_lptim_cnt_action_set(struct counter_device *counter,
drivers/counter/ti-eqep.c +16 -11
@@ -157,7 +157,7 @@ static int ti_eqep_action_get(struct counter_device *counter,* QEPA and QEPB trigger QCLK. */ *action =TI_EQEP_SYNAPSE_ACTION_BOTH_EDGES ; -break ; +return 0 ;case TI_EQEP_COUNT_FUNC_DIR_COUNT :/* In direction-count mode only rising edge of QEPA is counted * and QEPB gives direction.
@@ -165,12 +165,14 @@ static int ti_eqep_action_get(struct counter_device *counter,switch (synapse->signal->id) {case TI_EQEP_SIGNAL_QEPA : *action =TI_EQEP_SYNAPSE_ACTION_RISING_EDGE ; -break ; -default : +return 0 ; +case TI_EQEP_SIGNAL_QEPB : *action =TI_EQEP_SYNAPSE_ACTION_NONE ; -break ; +return 0 ; +default : +/* should never reach this path */ +return -EINVAL ; } -break ;case TI_EQEP_COUNT_FUNC_UP_COUNT :case TI_EQEP_COUNT_FUNC_DOWN_COUNT :/* In up/down-count modes only QEPA is counted and QEPB is not
@@ -186,15 +188,18 @@ static int ti_eqep_action_get(struct counter_device *counter, *action =TI_EQEP_SYNAPSE_ACTION_BOTH_EDGES ; else *action =TI_EQEP_SYNAPSE_ACTION_RISING_EDGE ; -break ; -default : +return 0 ; +case TI_EQEP_SIGNAL_QEPB : *action =TI_EQEP_SYNAPSE_ACTION_NONE ; -break ; +return 0 ; +default : +/* should never reach this path */ +return -EINVAL ; } -break ; +default : +/* should never reach this path */ +return -EINVAL ; } - -return 0 ; }static const struct counter_ops ti_eqep_counter_ops = {
Signature · 1 line
2.32.0
PATCH v13 3/17 counter: Standardize to ERANGE for limit exceeded errors
In reply to William Breathitt GrayERANGE is a semantically better error code to return when an argument value falls outside the supported limit range of a device.
Cc Jarkko Nikula <[email protected]>
Cc Oleksij Rempel <[email protected]>
Cc Maxime Coquelin <[email protected]>
Cc Alexandre Torgue <[email protected]>
Reviewed-by David Lechner <[email protected]>
Reviewed-by Fabrice Gasnier <[email protected]>
Signed-off-by William Breathitt Gray <[email protected]>
--- drivers/counter/104-quad-8.c | 6 +++--- drivers/counter/intel-qep.c | 2 +- drivers/counter/interrupt-cnt.c | 3 +++ drivers/counter/stm32-lptimer-cnt.c | 2 +- 4 files changed, 8 insertions(+), 5 deletions(-)
drivers/counter/104-quad-8.c +3 -3
@@ -154,7 +154,7 @@ static int quad8_count_write(struct counter_device *counter,/* Only 24-bit values are supported */ if (val >0xFFFFFF ) -return -EINVAL ; +return -ERANGE ;mutex_lock (&priv->lock);
@@ -669,7 +669,7 @@ static ssize_t quad8_count_preset_write(struct counter_device *counter,/* Only 24-bit values are supported */ if (preset >0xFFFFFF ) -return -EINVAL ; +return -ERANGE ;mutex_lock (&priv->lock);
@@ -714,7 +714,7 @@ static ssize_t quad8_count_ceiling_write(struct counter_device *counter,/* Only 24-bit values are supported */ if (ceiling >0xFFFFFF ) -return -EINVAL ; +return -ERANGE ;mutex_lock (&priv->lock);
drivers/counter/intel-qep.c +1 -1
@@ -320,7 +320,7 @@ static ssize_t spike_filter_ns_write(struct counter_device *counter, }if (length >INTEL_QEPFLT_MAX_COUNT (length)) -return -EINVAL ; +return -ERANGE ;mutex_lock (&qep->lock);if (qep->enabled) {
drivers/counter/interrupt-cnt.c +3 -0
@@ -107,6 +107,9 @@ static int interrupt_cnt_write(struct counter_device *counter, {struct interrupt_cnt_priv *priv = counter->priv; + if (val != (typeof(priv->count.counter))val) +return -ERANGE ; +atomic_set (&priv->count, val);return 0 ;
drivers/counter/stm32-lptimer-cnt.c +1 -1
@@ -283,7 +283,7 @@ static ssize_t stm32_lptim_cnt_ceiling_write(struct counter_device *counter,return ret;if (ceiling >STM32_LPTIM_MAX_ARR ) -return -EINVAL ; +return -ERANGE ; priv->ceiling = ceiling;
Signature · 1 line
2.32.0
PATCH v13 4/17 counter: Rename counter_signal_value to counter_signal_level
In reply to William Breathitt GraySignal values will always be levels so let's be explicit it about it to make the intent of the code clear.
Cc Oleksij Rempel <[email protected]>
Cc Kamel Bouhara <[email protected]>
Reviewed-by David Lechner <[email protected]>
Signed-off-by William Breathitt Gray <[email protected]>
--- drivers/counter/104-quad-8.c | 5 +++-- drivers/counter/counter.c | 12 ++++++------ drivers/counter/interrupt-cnt.c | 4 ++-- drivers/counter/microchip-tcb-capture.c | 4 ++-- include/linux/counter.h | 12 ++++++------ 5 files changed, 19 insertions(+), 18 deletions(-)
drivers/counter/104-quad-8.c +3 -2
@@ -97,7 +97,8 @@ struct quad8 {#define QUAD8_CMR_QUADRATURE_X4 0x18static int quad8_signal_read (struct counter_device *counter, -struct counter_signal *signal,enum counter_signal_value *val) +struct counter_signal *signal, +enum counter_signal_level *level) {const struct quad8 *const priv = counter->priv;unsigned int state;
@@ -109,7 +110,7 @@ static int quad8_signal_read(struct counter_device *counter, state =inb (priv->base +QUAD8_REG_INDEX_INPUT_LEVELS ) &BIT (signal->id -16 ); - *val = (state) ?COUNTER_SIGNAL_HIGH :COUNTER_SIGNAL_LOW ; + *level = (state) ?COUNTER_SIGNAL_LEVEL_HIGH :COUNTER_SIGNAL_LEVEL_LOW ;return 0 ; }
drivers/counter/counter.c +6 -6
@@ -289,9 +289,9 @@ struct counter_signal_unit {struct counter_signal *signal; }; -static const char *const counter_signal_value_str[] = { - [COUNTER_SIGNAL_LOW ] ="low" , - [COUNTER_SIGNAL_HIGH ] ="high" +static const char *const counter_signal_level_str[] = { + [COUNTER_SIGNAL_LEVEL_LOW ] ="low" , + [COUNTER_SIGNAL_LEVEL_HIGH ] ="high" }; static ssize_t counter_signal_show(struct device *dev,
@@ -302,13 +302,13 @@ static ssize_t counter_signal_show(struct device *dev,const struct counter_signal_unit *const component = devattr->component;struct counter_signal *const signal = component->signal;int err; -enum counter_signal_value val; +enum counter_signal_level level; - err = counter->ops->signal_read (counter, signal, &val); + err = counter->ops->signal_read (counter, signal, &level);if (err)return err; -return sprintf (buf,"%s\n" , counter_signal_value_str[val]); +return sprintf (buf,"%s\n" , counter_signal_level_str[level]); }struct counter_name_unit {
drivers/counter/interrupt-cnt.c +2 -2
@@ -130,7 +130,7 @@ static int interrupt_cnt_function_get(struct counter_device *counter,static int interrupt_cnt_signal_read (struct counter_device *counter,struct counter_signal *signal, -enum counter_signal_value *val) +enum counter_signal_level *level) {struct interrupt_cnt_priv *priv = counter->priv;int ret;
@@ -142,7 +142,7 @@ static int interrupt_cnt_signal_read(struct counter_device *counter,if (ret <0 )return ret; - *val = ret ?COUNTER_SIGNAL_HIGH :COUNTER_SIGNAL_LOW ; + *level = ret ?COUNTER_SIGNAL_LEVEL_HIGH :COUNTER_SIGNAL_LEVEL_LOW ;return 0 ; }
drivers/counter/microchip-tcb-capture.c +2 -2
@@ -158,7 +158,7 @@ static int mchp_tc_count_function_set(struct counter_device *counter,static int mchp_tc_count_signal_read (struct counter_device *counter,struct counter_signal *signal, -enum counter_signal_value *val) +enum counter_signal_level *lvl) {struct mchp_tc_data *const priv = counter->priv;bool sigstatus;
@@ -171,7 +171,7 @@ static int mchp_tc_count_signal_read(struct counter_device *counter,else sigstatus = (sr &ATMEL_TC_MTIOA ); - *val = sigstatus ?COUNTER_SIGNAL_HIGH :COUNTER_SIGNAL_LOW ; + *lvl = sigstatus ?COUNTER_SIGNAL_LEVEL_HIGH :COUNTER_SIGNAL_LEVEL_LOW ;return 0 ; }
include/linux/counter.h +6 -6
@@ -290,16 +290,16 @@ struct counter_device_state {const struct attribute_group **groups; }; -enum counter_signal_value { -COUNTER_SIGNAL_LOW =0 , -COUNTER_SIGNAL_HIGH +enum counter_signal_level { +COUNTER_SIGNAL_LEVEL_LOW , +COUNTER_SIGNAL_LEVEL_HIGH , };/** * struct counter_ops - Callbacks from driver * @signal_read: optional read callback for Signal attribute. The read -* value of the respective Signal should be passed back via -* the val parameter. +* level of the respective Signal should be passed back via +* the level parameter. * @count_read: optional read callback for Count attribute. The read * value of the respective Count should be passed back via * the val parameter.
@@ -324,7 +324,7 @@ enum counter_signal_value {struct counter_ops {int (*signal_read)(struct counter_device *counter,struct counter_signal *signal, -enum counter_signal_value *val); +enum counter_signal_level *level);int (*count_read)(struct counter_device *counter,struct counter_count *count,unsigned long *val); int (*count_write)(struct counter_device *counter,
Signature · 1 line
2.32.0
PATCH v13 5/17 counter: Rename counter_count_function to counter_function
In reply to William Breathitt GrayThe phrase "Counter Count function" is verbose and unintentionally implies that function is a Count extension. This patch adjusts the Counter subsystem code to use the more direct "Counter function" phrase to make the intent of this code clearer.
Cc Jarkko Nikula <[email protected]>
Cc Patrick Havelange <[email protected]>
Cc Oleksij Rempel <[email protected]>
Cc Kamel Bouhara <[email protected]>
Cc Maxime Coquelin <[email protected]>
Cc Alexandre Torgue <[email protected]>
Cc David Lechner <[email protected]>
Reviewed-by Fabrice Gasnier <[email protected]>
Signed-off-by William Breathitt Gray <[email protected]>
--- drivers/counter/104-quad-8.c | 10 +++---- drivers/counter/counter.c | 38 ++++++++++++------------- drivers/counter/ftm-quaddec.c | 5 ++-- drivers/counter/intel-qep.c | 4 +-- drivers/counter/interrupt-cnt.c | 4 +-- drivers/counter/microchip-tcb-capture.c | 4 +-- drivers/counter/stm32-lptimer-cnt.c | 6 ++-- drivers/counter/stm32-timer-cnt.c | 10 +++---- drivers/counter/ti-eqep.c | 10 +++---- include/linux/counter.h | 20 ++++++------- 10 files changed, 55 insertions(+), 56 deletions(-)
drivers/counter/104-quad-8.c +5 -5
@@ -194,11 +194,11 @@ enum quad8_count_function {QUAD8_COUNT_FUNCTION_QUADRATURE_X4 }; -static const enum counter_count_function quad8_count_functions_list[] = { - [QUAD8_COUNT_FUNCTION_PULSE_DIRECTION ] =COUNTER_COUNT_FUNCTION_PULSE_DIRECTION , - [QUAD8_COUNT_FUNCTION_QUADRATURE_X1 ] =COUNTER_COUNT_FUNCTION_QUADRATURE_X1_A , - [QUAD8_COUNT_FUNCTION_QUADRATURE_X2 ] =COUNTER_COUNT_FUNCTION_QUADRATURE_X2_A , - [QUAD8_COUNT_FUNCTION_QUADRATURE_X4 ] =COUNTER_COUNT_FUNCTION_QUADRATURE_X4 +static const enum counter_function quad8_count_functions_list[] = { + [QUAD8_COUNT_FUNCTION_PULSE_DIRECTION ] =COUNTER_FUNCTION_PULSE_DIRECTION , + [QUAD8_COUNT_FUNCTION_QUADRATURE_X1 ] =COUNTER_FUNCTION_QUADRATURE_X1_A , + [QUAD8_COUNT_FUNCTION_QUADRATURE_X2 ] =COUNTER_FUNCTION_QUADRATURE_X2_A , + [QUAD8_COUNT_FUNCTION_QUADRATURE_X4 ] =COUNTER_FUNCTION_QUADRATURE_X4 }; static int quad8_function_get(struct counter_device *counter,
drivers/counter/counter.c +19 -19
@@ -744,15 +744,15 @@ static ssize_t counter_count_store(struct device *dev,return len; } -static const char *const counter_count_function_str[] = { - [COUNTER_COUNT_FUNCTION_INCREASE ] ="increase" , - [COUNTER_COUNT_FUNCTION_DECREASE ] ="decrease" , - [COUNTER_COUNT_FUNCTION_PULSE_DIRECTION ] ="pulse-direction" , - [COUNTER_COUNT_FUNCTION_QUADRATURE_X1_A ] ="quadrature x1 a" , - [COUNTER_COUNT_FUNCTION_QUADRATURE_X1_B ] ="quadrature x1 b" , - [COUNTER_COUNT_FUNCTION_QUADRATURE_X2_A ] ="quadrature x2 a" , - [COUNTER_COUNT_FUNCTION_QUADRATURE_X2_B ] ="quadrature x2 b" , - [COUNTER_COUNT_FUNCTION_QUADRATURE_X4 ] ="quadrature x4" +static const char *const counter_function_str[] = { + [COUNTER_FUNCTION_INCREASE ] ="increase" , + [COUNTER_FUNCTION_DECREASE ] ="decrease" , + [COUNTER_FUNCTION_PULSE_DIRECTION ] ="pulse-direction" , + [COUNTER_FUNCTION_QUADRATURE_X1_A ] ="quadrature x1 a" , + [COUNTER_FUNCTION_QUADRATURE_X1_B ] ="quadrature x1 b" , + [COUNTER_FUNCTION_QUADRATURE_X2_A ] ="quadrature x2 a" , + [COUNTER_FUNCTION_QUADRATURE_X2_B ] ="quadrature x2 b" , + [COUNTER_FUNCTION_QUADRATURE_X4 ] ="quadrature x4" }; static ssize_t counter_function_show(struct device *dev,
@@ -764,7 +764,7 @@ static ssize_t counter_function_show(struct device *dev,const struct counter_count_unit *const component = devattr->component;struct counter_count *const count = component->count;size_t func_index; -enum counter_count_function function; +enum counter_function function; err = counter->ops->function_get (counter, count, &func_index);if (err)
@@ -773,7 +773,7 @@ static ssize_t counter_function_show(struct device *dev, count->function = func_index; function = count->functions_list[func_index]; -return sprintf (buf,"%s\n" , counter_count_function_str[function]); +return sprintf (buf,"%s\n" , counter_function_str[function]); } static ssize_t counter_function_store(struct device *dev,
@@ -785,14 +785,14 @@ static ssize_t counter_function_store(struct device *dev,struct counter_count *const count = component->count;const size_t num_functions = count->num_functions;size_t func_index; -enum counter_count_function function; +enum counter_function function;int err;struct counter_device *const counter =dev_get_drvdata (dev);/* Find requested Count function mode */ for (func_index =0 ; func_index < num_functions; func_index++) { function = count->functions_list[func_index]; -if (sysfs_streq (buf, counter_count_function_str[function])) +if (sysfs_streq (buf, counter_function_str[function]))break ; }/* Return error if requested Count function mode not found */
@@ -880,25 +880,25 @@ static int counter_count_ext_register( }struct counter_func_avail_unit { -const enum counter_count_function *functions_list; +const enum counter_function *functions_list;size_t num_functions; }; -static ssize_t counter_count_function_available_show (struct device *dev, +static ssize_t counter_function_available_show (struct device *dev,struct device_attribute *attr,char *buf) {const struct counter_device_attr *const devattr =to_counter_attr (attr);const struct counter_func_avail_unit *const component = devattr->component; -const enum counter_count_function *const func_list = component->functions_list; +const enum counter_function *const func_list = component->functions_list;const size_t num_functions = component->num_functions;size_t i; -enum counter_count_function function; +enum counter_function function;ssize_t len =0 ;for (i =0 ; i < num_functions; i++) { function = func_list[i]; len +=sprintf (buf + len,"%s\n" , - counter_count_function_str[function]); + counter_function_str[function]); }return len;
@@ -968,7 +968,7 @@ static int counter_count_attributes_create( parm.group = group; parm.prefix ="" ; parm.name ="function_available" ; - parm.show = counter_count_function_available_show; + parm.show = counter_function_available_show; parm.store =NULL ; parm.component = avail_comp; err =counter_attribute_create (&parm);
drivers/counter/ftm-quaddec.c +2 -3
@@ -171,9 +171,8 @@ enum ftm_quaddec_count_function { FTM_QUADDEC_COUNT_ENCODER_MODE_1, }; -static const enum counter_count_function ftm_quaddec_count_functions[] = { - [FTM_QUADDEC_COUNT_ENCODER_MODE_1 ] = -COUNTER_COUNT_FUNCTION_QUADRATURE_X4 +static const enum counter_function ftm_quaddec_count_functions[] = { + [FTM_QUADDEC_COUNT_ENCODER_MODE_1 ] =COUNTER_FUNCTION_QUADRATURE_X4 }; static int ftm_quaddec_count_read(struct counter_device *counter,
drivers/counter/intel-qep.c +2 -2
@@ -127,8 +127,8 @@ static int intel_qep_count_read(struct counter_device *counter,return 0 ; } -static const enum counter_count_function intel_qep_count_functions[] = { -COUNTER_COUNT_FUNCTION_QUADRATURE_X4 , +static const enum counter_function intel_qep_count_functions[] = { +COUNTER_FUNCTION_QUADRATURE_X4 , }; static int intel_qep_function_get(struct counter_device *counter,
drivers/counter/interrupt-cnt.c +2 -2
@@ -115,8 +115,8 @@ static int interrupt_cnt_write(struct counter_device *counter,return 0 ; } -static const enum counter_count_function interrupt_cnt_functions[] = { -COUNTER_COUNT_FUNCTION_INCREASE , +static const enum counter_function interrupt_cnt_functions[] = { +COUNTER_FUNCTION_INCREASE , }; static int interrupt_cnt_function_get(struct counter_device *counter,
drivers/counter/microchip-tcb-capture.c +2 -2
@@ -38,8 +38,8 @@ enum mchp_tc_count_function { };static const enum counter_count_function mchp_tc_count_functions[] = { - [MCHP_TC_FUNCTION_INCREASE ] =COUNTER_COUNT_FUNCTION_INCREASE , - [MCHP_TC_FUNCTION_QUADRATURE ] =COUNTER_COUNT_FUNCTION_QUADRATURE_X4 , + [MCHP_TC_FUNCTION_INCREASE ] =COUNTER_FUNCTION_INCREASE , + [MCHP_TC_FUNCTION_QUADRATURE ] =COUNTER_FUNCTION_QUADRATURE_X4 , };enum mchp_tc_synapse_action {
drivers/counter/stm32-lptimer-cnt.c +3 -3
@@ -134,9 +134,9 @@ enum stm32_lptim_cnt_function { STM32_LPTIM_ENCODER_BOTH_EDGE, }; -static const enum counter_count_function stm32_lptim_cnt_functions[] = { - [STM32_LPTIM_COUNTER_INCREASE ] =COUNTER_COUNT_FUNCTION_INCREASE , - [STM32_LPTIM_ENCODER_BOTH_EDGE ] =COUNTER_COUNT_FUNCTION_QUADRATURE_X4 , +static const enum counter_function stm32_lptim_cnt_functions[] = { + [STM32_LPTIM_COUNTER_INCREASE ] =COUNTER_FUNCTION_INCREASE , + [STM32_LPTIM_ENCODER_BOTH_EDGE ] =COUNTER_FUNCTION_QUADRATURE_X4 , };enum stm32_lptim_synapse_action {
drivers/counter/stm32-timer-cnt.c +5 -5
@@ -50,11 +50,11 @@ enum stm32_count_function { STM32_COUNT_ENCODER_MODE_3, }; -static const enum counter_count_function stm32_count_functions[] = { - [STM32_COUNT_SLAVE_MODE_DISABLED ] =COUNTER_COUNT_FUNCTION_INCREASE , - [STM32_COUNT_ENCODER_MODE_1 ] =COUNTER_COUNT_FUNCTION_QUADRATURE_X2_A , - [STM32_COUNT_ENCODER_MODE_2 ] =COUNTER_COUNT_FUNCTION_QUADRATURE_X2_B , - [STM32_COUNT_ENCODER_MODE_3 ] =COUNTER_COUNT_FUNCTION_QUADRATURE_X4 , +static const enum counter_function stm32_count_functions[] = { + [STM32_COUNT_SLAVE_MODE_DISABLED ] =COUNTER_FUNCTION_INCREASE , + [STM32_COUNT_ENCODER_MODE_1 ] =COUNTER_FUNCTION_QUADRATURE_X2_A , + [STM32_COUNT_ENCODER_MODE_2 ] =COUNTER_FUNCTION_QUADRATURE_X2_B , + [STM32_COUNT_ENCODER_MODE_3 ] =COUNTER_FUNCTION_QUADRATURE_X4 , }; static int stm32_count_read(struct counter_device *counter,
drivers/counter/ti-eqep.c +5 -5
@@ -294,11 +294,11 @@ static struct counter_signal ti_eqep_signals[] = { }, }; -static const enum counter_count_function ti_eqep_position_functions[] = { - [TI_EQEP_COUNT_FUNC_QUAD_COUNT ] =COUNTER_COUNT_FUNCTION_QUADRATURE_X4 , - [TI_EQEP_COUNT_FUNC_DIR_COUNT ] =COUNTER_COUNT_FUNCTION_PULSE_DIRECTION , - [TI_EQEP_COUNT_FUNC_UP_COUNT ] =COUNTER_COUNT_FUNCTION_INCREASE , - [TI_EQEP_COUNT_FUNC_DOWN_COUNT ] =COUNTER_COUNT_FUNCTION_DECREASE , +static const enum counter_function ti_eqep_position_functions[] = { + [TI_EQEP_COUNT_FUNC_QUAD_COUNT ] =COUNTER_FUNCTION_QUADRATURE_X4 , + [TI_EQEP_COUNT_FUNC_DIR_COUNT ] =COUNTER_FUNCTION_PULSE_DIRECTION , + [TI_EQEP_COUNT_FUNC_UP_COUNT ] =COUNTER_FUNCTION_INCREASE , + [TI_EQEP_COUNT_FUNC_DOWN_COUNT ] =COUNTER_FUNCTION_DECREASE , };static const enum counter_synapse_action ti_eqep_position_synapse_actions[] = {
include/linux/counter.h +10 -10
@@ -162,15 +162,15 @@ struct counter_count_ext {void *priv; }; -enum counter_count_function { -COUNTER_COUNT_FUNCTION_INCREASE =0 , -COUNTER_COUNT_FUNCTION_DECREASE , -COUNTER_COUNT_FUNCTION_PULSE_DIRECTION , -COUNTER_COUNT_FUNCTION_QUADRATURE_X1_A , -COUNTER_COUNT_FUNCTION_QUADRATURE_X1_B , -COUNTER_COUNT_FUNCTION_QUADRATURE_X2_A , -COUNTER_COUNT_FUNCTION_QUADRATURE_X2_B , -COUNTER_COUNT_FUNCTION_QUADRATURE_X4 +enum counter_function { +COUNTER_FUNCTION_INCREASE =0 , +COUNTER_FUNCTION_DECREASE , +COUNTER_FUNCTION_PULSE_DIRECTION , +COUNTER_FUNCTION_QUADRATURE_X1_A , +COUNTER_FUNCTION_QUADRATURE_X1_B , +COUNTER_FUNCTION_QUADRATURE_X2_A , +COUNTER_FUNCTION_QUADRATURE_X2_B , +COUNTER_FUNCTION_QUADRATURE_X4 };/**
@@ -192,7 +192,7 @@ struct counter_count {const char *name;size_t function; -const enum counter_count_function *functions_list; +const enum counter_function *functions_list;size_t num_functions;struct counter_synapse *synapses;
Signature · 1 line
2.32.0
PATCH v13 6/17 counter: Internalize sysfs interface code
In reply to William Breathitt GrayThis is a reimplementation of the Generic Counter driver interface. There are no modifications to the Counter subsystem userspace interface, so existing userspace applications should continue to run seamlessly.
The purpose of this patch is to internalize the sysfs interface code among the various counter drivers into a shared module. Counter drivers pass and take data natively (i.e. u8, u64, etc.) and the shared counter module handles the translation between the sysfs interface and the device drivers. This guarantees a standard userspace interface for all counter drivers, and helps generalize the Generic Counter driver ABI in order to support the Generic Counter chrdev interface (introduced in a subsequent patch) without significant changes to the existing counter drivers.
Note, Counter device registration is the same as before: drivers populate a struct counter_device with components and callbacks, then pass the structure to the devm_counter_register function. However, what's different now is how the Counter subsystem code handles this registration internally.
Whereas before callbacks would interact directly with sysfs data, this interaction is now abstracted and instead callbacks interact with native C data types. The counter_comp structure forms the basis for Counter extensions.
The counter-sysfs.c file contains the code to parse through the counter_device structure and register the requested components and extensions. Attributes are created and populated based on type, with respective translation functions to handle the mapping between sysfs and the counter driver callbacks.
The translation performed for each attribute is straightforward: the attribute type and data is parsed from the counter_attribute structure, the respective counter driver read/write callback is called, and sysfs I/O is handled before or after the driver read/write function is called.
Cc Jarkko Nikula <[email protected]>
Cc Patrick Havelange <[email protected]>
Cc Kamel Bouhara <[email protected]>
Cc Fabrice Gasnier <[email protected]>
Cc Maxime Coquelin <[email protected]>
Cc Alexandre Torgue <[email protected]>
Cc Dan Carpenter <[email protected]>
Reviewed-by David Lechner <[email protected]>
Tested-by David Lechner <[email protected]>
Signed-off-by William Breathitt Gray <[email protected]>
--- MAINTAINERS | 1 - drivers/counter/104-quad-8.c | 449 +++---- drivers/counter/Makefile | 1 + drivers/counter/counter-core.c | 145 +++ drivers/counter/counter-sysfs.c | 852 +++++++++++++ drivers/counter/counter-sysfs.h | 13 + drivers/counter/counter.c | 1496 ----------------------- drivers/counter/ftm-quaddec.c | 56 +- drivers/counter/intel-qep.c | 144 +-- drivers/counter/interrupt-cnt.c | 62 +- drivers/counter/microchip-tcb-capture.c | 93 +- drivers/counter/stm32-lptimer-cnt.c | 197 +-- drivers/counter/stm32-timer-cnt.c | 147 +-- drivers/counter/ti-eqep.c | 180 +-- include/linux/counter.h | 658 +++++----- include/linux/counter_enum.h | 45 - 16 files changed, 1959 insertions(+), 2580 deletions(-) create mode 100644 drivers/counter/counter-core.c create mode 100644 drivers/counter/counter-sysfs.c create mode 100644 drivers/counter/counter-sysfs.h delete mode 100644 drivers/counter/counter.c delete mode 100644 include/linux/counter_enum.h
MAINTAINERS +0 -1
@@ -4748,7 +4748,6 @@ F: Documentation/ABI/testing/sysfs-bus-counter F: Documentation/driver-api/generic-counter.rst F: drivers/counter/ F: include/linux/counter.h -F: include/linux/counter_enum.h CP2615 I2C DRIVER M: Bence Csókás <[email protected]>
drivers/counter/104-quad-8.c +191 -258
796 lines not on this page · raw message
drivers/counter/Makefile +1 -0
@@ -4,6 +4,7 @@ # obj-$(CONFIG_COUNTER) += counter.o +counter-y := counter-core.o counter-sysfs.o obj-$(CONFIG_104_QUAD_8) += 104-quad-8.o obj-$(CONFIG_INTERRUPT_CNT) += interrupt-cnt.o
drivers/counter/counter-core.c new file +145 -0
145 lines not on this page · raw message
drivers/counter/counter-sysfs.c new file +852 -0
852 lines not on this page · raw message
drivers/counter/counter-sysfs.h new file +13 -0
@@ -0,0 +1,13 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* +* Counter sysfs interface +* Copyright (C) 2020 William Breathitt Gray +*/ +#ifndef _COUNTER_SYSFS_H_ +#define _COUNTER_SYSFS_H_ + +#include <linux/counter.h> + +int counter_sysfs_add (struct counter_device *const counter); + +#endif /* _COUNTER_SYSFS_H_ */
drivers/counter/counter.c deleted +0 -1496
1,180 lines not on this page · raw message
drivers/counter/ftm-quaddec.c +23 -33
56 lines not on this page · raw message
drivers/counter/intel-qep.c +61 -83
144 lines not on this page · raw message
drivers/counter/interrupt-cnt.c +26 -36
62 lines not on this page · raw message
drivers/counter/microchip-tcb-capture.c +40 -53
93 lines not on this page · raw message
drivers/counter/stm32-lptimer-cnt.c +112 -85
197 lines not on this page · raw message
drivers/counter/stm32-timer-cnt.c +59 -88
147 lines not on this page · raw message
drivers/counter/ti-eqep.c +98 -82
180 lines not on this page · raw message
include/linux/counter.h +338 -320
658 lines not on this page · raw message
include/linux/counter_enum.h deleted +0 -45
45 lines not on this page · raw message
The rest of this diff is not shown. View the raw message.
Signature · 1 line
2.32.0
Part of the diff is not shown here. View the raw message.
PATCH v13 7/17 counter: Update counter.h comments to reflect sysfs internalization
In reply to William Breathitt GrayThe Counter subsystem architecture and driver implementations have changed in order to handle Counter sysfs interactions in a more consistent way. This patch updates the Generic Counter interface header file comments to reflect the changes.
Signed-off-by William Breathitt Gray <[email protected]>
--- drivers/counter/counter-core.c | 3 ++ include/linux/counter.h | 62 ++++++++++++++++------------------ 2 files changed, 33 insertions(+), 32 deletions(-)
drivers/counter/counter-core.c +3 -0
@@ -41,6 +41,9 @@ static struct bus_type counter_bus_type = {* This function registers a Counter to the system. A sysfs "counter" directory * will be created and populated with sysfs attributes correlating with the * Counter Signals, Synapses, and Counts respectively. +* +* RETURNS: +* 0 on success, negative error number on failure. */ int counter_register (struct counter_device *const counter) {
include/linux/counter.h +30 -32
97 lines not on this page · raw message
Signature · 1 line
2.32.0
PATCH v13 8/17 docs: counter: Update to reflect sysfs internalization
In reply to William Breathitt GrayThe Counter subsystem architecture and driver implementations have changed in order to handle Counter sysfs interactions in a more consistent way. This patch updates the Generic Counter interface documentation to reflect the changes.
Reviewed-by David Lechner <[email protected]>
Signed-off-by William Breathitt Gray <[email protected]>
--- Documentation/ABI/testing/sysfs-bus-counter | 9 +- Documentation/driver-api/generic-counter.rst | 243 ++++++++++++++----- 2 files changed, 185 insertions(+), 67 deletions(-)
Documentation/ABI/testing/sysfs-bus-counter +8 -1
@@ -286,7 +286,14 @@ What: /sys/bus/counter/devices/counterX/signalY/signal KernelVersion: 5.2 Contact: [email protected] Description: - Signal data of Signal Y represented as a string. + Signal level state of Signal Y. The following signal level + states are available: + + low: + Low level state. + + high: + High level state. What: /sys/bus/counter/devices/counterX/signalY/synchronous_mode KernelVersion: 5.2
Documentation/driver-api/generic-counter.rst +177 -66
262 lines not on this page · raw message
Signature · 1 line
2.32.0
PATCH v13 9/17 counter: Move counter enums to uapi header
In reply to William Breathitt GrayThis is in preparation for a subsequent patch implementing a character device interface for the Counter subsystem.
Reviewed-by David Lechner <[email protected]>
Signed-off-by William Breathitt Gray <[email protected]>
--- MAINTAINERS | 1 + include/linux/counter.h | 42 +-------------------------- include/uapi/linux/counter.h | 56 ++++++++++++++++++++++++++++++++++++ 3 files changed, 58 insertions(+), 41 deletions(-) create mode 100644 include/uapi/linux/counter.h
MAINTAINERS +1 -0
@@ -4748,6 +4748,7 @@ F: Documentation/ABI/testing/sysfs-bus-counter F: Documentation/driver-api/generic-counter.rst F: drivers/counter/ F: include/linux/counter.h +F: include/uapi/linux/counter.h CP2615 I2C DRIVER M: Bence Csókás <[email protected]>
include/linux/counter.h +1 -41
54 lines not on this page · raw message
include/uapi/linux/counter.h new file +56 -0
56 lines not on this page · raw message
Signature · 1 line
2.32.0
PATCH v13 10/17 counter: Add character device interface
In reply to William Breathitt GrayThis patch introduces a character device interface for the Counter subsystem. Device data is exposed through standard character device read operations. Device data is gathered when a Counter event is pushed by the respective Counter device driver. Configuration is handled via ioctl operations on the respective Counter character device node.
Cc David Lechner <[email protected]>
Cc Gwendal Grignou <[email protected]>
Cc Dan Carpenter <[email protected]>
Cc Oleksij Rempel <[email protected]>
Signed-off-by William Breathitt Gray <[email protected]>
--- drivers/counter/Makefile | 2 +- drivers/counter/counter-chrdev.c | 508 +++++++++++++++++++++++++++++++ drivers/counter/counter-chrdev.h | 14 + drivers/counter/counter-core.c | 44 ++- include/linux/counter.h | 47 +++ include/uapi/linux/counter.h | 98 ++++++ 6 files changed, 707 insertions(+), 6 deletions(-) create mode 100644 drivers/counter/counter-chrdev.c create mode 100644 drivers/counter/counter-chrdev.h
drivers/counter/Makefile +1 -1
@@ -4,7 +4,7 @@ # obj-$(CONFIG_COUNTER) += counter.o -counter-y := counter-core.o counter-sysfs.o +counter-y := counter-core.o counter-sysfs.o counter-chrdev.o obj-$(CONFIG_104_QUAD_8) += 104-quad-8.o obj-$(CONFIG_INTERRUPT_CNT) += interrupt-cnt.o
drivers/counter/counter-chrdev.c new file +508 -0
508 lines not on this page · raw message
drivers/counter/counter-chrdev.h new file +14 -0
@@ -0,0 +1,14 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* +* Counter character device interface +* Copyright (C) 2020 William Breathitt Gray +*/ +#ifndef _COUNTER_CHRDEV_H_ +#define _COUNTER_CHRDEV_H_ + +#include <linux/counter.h> + +int counter_chrdev_add (struct counter_device *const counter); +void counter_chrdev_remove (struct counter_device *const counter); + +#endif /* _COUNTER_CHRDEV_H_ */
drivers/counter/counter-core.c +39 -5
103 lines not on this page · raw message
include/linux/counter.h +47 -0
92 lines not on this page · raw message
include/uapi/linux/counter.h +98 -0
110 lines not on this page · raw message
Signature · 1 line
2.32.0
PATCH v13 11/17 docs: counter: Document character device interface
In reply to William Breathitt GrayThis patch adds high-level documentation about the Counter subsystem character device interface.
Signed-off-by William Breathitt Gray <[email protected]>
--- Documentation/driver-api/generic-counter.rst | 177 ++++++++++++++---- .../userspace-api/ioctl/ioctl-number.rst | 1 + 2 files changed, 137 insertions(+), 41 deletions(-)
Documentation/driver-api/generic-counter.rst +136 -41
@@ -223,19 +223,6 @@ whether an input line is differential or single-ended) and instead focus on the core idea of what the data and process represent (e.g. position as interpreted from quadrature encoding data). -Userspace Interface -=================== - -Several sysfs attributes are generated by the Generic Counter interface, -and reside under the /sys/bus/counter/devices/counterX directory, where -counterX refers to the respective counter device. Please see -Documentation/ABI/testing/sysfs-bus-counter for detailed -information on each Generic Counter interface sysfs attribute. - -Through these sysfs attributes, programs and scripts may interact with -the Generic Counter paradigm Counts, Signals, and Synapses of respective -counter devices. - Driver API ==========
@@ -388,16 +375,16 @@ userspace interface components:: / driver callbacks / ------------------- | - +---------------+ - | - V - +--------------------+ - | Counter sysfs | - +--------------------+ - | Translates to the | - | standard Counter | - | sysfs output | - +--------------------+ + +---------------+---------------+ + | | + V V + +--------------------+ +---------------------+ + | Counter sysfs | | Counter chrdev | + +--------------------+ +---------------------+ + | Translates to the | | Translates to the | + | standard Counter | | standard Counter | + | sysfs output | | character device | + +--------------------+ +---------------------+ Thereafter, data can be transferred directly between the Counter device driver and Counter userspace interface::
@@ -428,23 +415,30 @@ driver and Counter userspace interface:: / u64 / ---------- | - +---------------+ - | - V - +--------------------+ - | Counter sysfs | - +--------------------+ - | Translates to the | - | standard Counter | - | sysfs output | - |--------------------| - | Type: const char * | - | Value: "42" | - +--------------------+ - | - --------------- - / const char * / - --------------- + +---------------+---------------+ + | | + V V + +--------------------+ +---------------------+ + | Counter sysfs | | Counter chrdev | + +--------------------+ +---------------------+ + | Translates to the | | Translates to the | + | standard Counter | | standard Counter | + | sysfs output | | character device | + |--------------------| |---------------------| + | Type: const char * | | Type: u64 | + | Value: "42" | | Value: 42 | + +--------------------+ +---------------------+ + | | + --------------- ----------------------- + / const char * / / struct counter_event / + --------------- ----------------------- + | | + | V + | +-----------+ + | | read | + | +-----------+ + | \ Count: 42 / + | ----------- | V +--------------------------------------------------+
@@ -453,7 +447,7 @@ driver and Counter userspace interface:: \ Count: "42" / -------------------------------------------------- -There are three primary components involved: +There are four primary components involved: Counter device driver ---------------------
@@ -473,3 +467,104 @@ and vice versa. Please refer to the ``Documentation/ABI/testing/sysfs-bus-counter`` file for a detailed breakdown of the available Generic Counter interface sysfs attributes. + +Counter chrdev +-------------- +Translates counter data to the standard Counter character device; data +is transferred via standard character device read calls, while Counter +events are configured via ioctl calls. + +Sysfs Interface +=============== + +Several sysfs attributes are generated by the Generic Counter interface, +and reside under the ``/sys/bus/counter/devices/counterX`` directory, +where ``X`` is to the respective counter device id. Please see +``Documentation/ABI/testing/sysfs-bus-counter`` for detailed information +on each Generic Counter interface sysfs attribute. + +Through these sysfs attributes, programs and scripts may interact with +the Generic Counter paradigm Counts, Signals, and Synapses of respective +counter devices. + +Counter Character Device +======================== + +Counter character device nodes are created under the ``/dev`` directory +as ``counterX``, where ``X`` is the respective counter device id. +Defines for the standard Counter data types are exposed via the +userspace ``include/uapi/linux/counter.h`` file. + +Counter events +-------------- +Counter device drivers can support Counter events by utilizing the +``counter_push_event`` function:: + + void counter_push_event(struct counter_device *const counter, const u8 event, + const u8 channel); + +The event id is specified by the ``event`` parameter; the event channel +id is specified by the ``channel`` parameter. When this function is +called, the Counter data associated with the respective event is +gathered, and a ``struct counter_event`` is generated for each datum and +pushed to userspace. + +Counter events can be configured by users to report various Counter +data of interest. This can be conceptualized as a list of Counter +component read calls to perform. For example: + + +-------------------------------------------------+ + | COUNTER_EVENT_OVERFLOW | COUNTER_EVENT_INDEX | + +========================+========================+ + | Channel 0 | Channel 0 | + +------------------------+------------------------+ + | * Count 0 | * Signal 0 | + | * Count 1 | * Signal 0 Extension 0 | + | * Signal 3 | * Extension 4 | + | * Count 4 Extension 2 +------------------------+ + | * Signal 5 Extension 0 | Channel 1 | + | +------------------------+ + | | * Signal 4 | + | | * Signal 4 Extension 0 | + | | * Count 7 | + +------------------------+------------------------+ + +When ``counter_push_event(counter, COUNTER_EVENT_INDEX, 1)`` is called +for example, it will go down the list for the ``COUNTER_EVENT_INDEX`` +event channel 1 and execute the read callbacks for Signal 4, Signal 4 +Extension 0, and Count 4 -- the data returned for each is pushed to a +kfifo as a ``struct counter_event``, which userspace can retrieve via a +standard read operation on the respective character device node. + +Userspace +--------- +Userspace applications can configure Counter events via ioctl operations +on the Counter character device node. There following ioctl codes are +supported and provided by the ``linux/counter.h`` userspace header file: + +* :c:macro:`COUNTER_ADD_WATCH_IOCTL` + +* :c:macro:`COUNTER_ENABLE_EVENTS_IOCTL` + +* :c:macro:`COUNTER_DISABLE_EVENTS_IOCTL` + +To configure events to gather Counter data, users first populate a +``struct counter_watch`` with the relevant event id, event channel id, +and the information for the desired Counter component from which to +read, and then pass it via the ``COUNTER_ADD_WATCH_IOCTL`` ioctl +command. + +Note that an event can be watched without gathering Counter data by +setting the ``component.type`` member equal to +``COUNTER_COMPONENT_NONE``. With this configuration the Counter +character device will simply populate the event timestamps for those +respective ``struct counter_event`` elements and ignore the component +value. + +The ``COUNTER_ADD_WATCH_IOCTL`` command will buffer these Counter +watches. When ready, the ``COUNTER_ENABLE_EVENTS_IOCTL`` ioctl command +may be used to activate these Counter watches. + +Userspace applications can then execute a ``read`` operation (optionally +calling ``poll`` first) on the Counter character device node to retrieve +``struct counter_event`` elements with the desired data.
Documentation/userspace-api/ioctl/ioctl-number.rst +1 -0
@@ -88,6 +88,7 @@ Code Seq# Include File Comments <http://infiniband.sourceforge.net/> 0x20 all drivers/cdrom/cm206.h 0x22 all scsi/sg.h +0x3E 00-0F linux/counter.h <mailto:[email protected]> '!' 00-1F uapi/linux/seccomp.h '#' 00-3F IEEE 1394 Subsystem Block for the entire subsystem
Signature · 1 line
2.32.0
PATCH v13 12/17 tools/counter: Create Counter tools
In reply to William Breathitt GrayThis creates an example Counter program under tools/counter/* to exemplify the Counter character device interface.
Cc Pavel Machek <[email protected]>
Signed-off-by William Breathitt Gray <[email protected]>
--- MAINTAINERS | 1 + tools/Makefile | 13 ++--- tools/counter/Build | 1 + tools/counter/Makefile | 53 +++++++++++++++++++ tools/counter/counter_example.c | 93 +++++++++++++++++++++++++++++++++ 5 files changed, 155 insertions(+), 6 deletions(-) create mode 100644 tools/counter/Build create mode 100644 tools/counter/Makefile create mode 100644 tools/counter/counter_example.c
MAINTAINERS +1 -0
@@ -4749,6 +4749,7 @@ F: Documentation/driver-api/generic-counter.rst F: drivers/counter/ F: include/linux/counter.h F: include/uapi/linux/counter.h +F: tools/counter/ CP2615 I2C DRIVER M: Bence Csókás <[email protected]>
tools/Makefile +7 -6
@@ -12,6 +12,7 @@ help: @echo ' acpi - ACPI tools' @echo ' bpf - misc BPF tools' @echo ' cgroup - cgroup tools' + @echo ' counter - counter tools' @echo ' cpupower - a tool for all things x86 CPU power' @echo ' debugging - tools for debugging' @echo ' firewire - the userspace part of nosy, an IEEE-1394 traffic sniffer'
@@ -65,7 +66,7 @@ acpi: FORCE cpupower: FORCE $(call descend,power/$@) -cgroup firewire hv guest bootconfig spi usb virtio vm bpf iio gpio objtool leds wmi pci firmware debugging tracing: FORCE +cgroup counter firewire hv guest bootconfig spi usb virtio vm bpf iio gpio objtool leds wmi pci firmware debugging tracing: FORCE $(call descend,$@) bpf/%: FORCE
@@ -100,7 +101,7 @@ freefall: FORCE kvm_stat: FORCE $(call descend,kvm/$@) -all: acpi cgroup cpupower gpio hv firewire liblockdep \ +all: acpi cgroup counter cpupower gpio hv firewire liblockdep \ perf selftests bootconfig spi turbostat usb \ virtio vm bpf x86_energy_perf_policy \ tmon freefall iio objtool kvm_stat wmi \
@@ -112,7 +113,7 @@ acpi_install: cpupower_install: $(call descend,power/$(@:_install=),install) -cgroup_install firewire_install gpio_install hv_install iio_install perf_install bootconfig_install spi_install usb_install virtio_install vm_install bpf_install objtool_install wmi_install pci_install debugging_install tracing_install: +cgroup_install counter_install firewire_install gpio_install hv_install iio_install perf_install bootconfig_install spi_install usb_install virtio_install vm_install bpf_install objtool_install wmi_install pci_install debugging_install tracing_install: $(call descend,$(@:_install=),install) liblockdep_install:
@@ -133,7 +134,7 @@ freefall_install: kvm_stat_install: $(call descend,kvm/$(@:_install=),install) -install: acpi_install cgroup_install cpupower_install gpio_install \ +install: acpi_install cgroup_install counter_install cpupower_install gpio_install \ hv_install firewire_install iio_install liblockdep_install \ perf_install selftests_install turbostat_install usb_install \ virtio_install vm_install bpf_install x86_energy_perf_policy_install \
@@ -147,7 +148,7 @@ acpi_clean: cpupower_clean: $(call descend,power/cpupower,clean) -cgroup_clean hv_clean firewire_clean bootconfig_clean spi_clean usb_clean virtio_clean vm_clean wmi_clean bpf_clean iio_clean gpio_clean objtool_clean leds_clean pci_clean firmware_clean debugging_clean tracing_clean: +cgroup_clean counter_clean hv_clean firewire_clean bootconfig_clean spi_clean usb_clean virtio_clean vm_clean wmi_clean bpf_clean iio_clean gpio_clean objtool_clean leds_clean pci_clean firmware_clean debugging_clean tracing_clean: $(call descend,$(@:_clean=),clean) liblockdep_clean:
@@ -181,7 +182,7 @@ freefall_clean: build_clean: $(call descend,build,clean) -clean: acpi_clean cgroup_clean cpupower_clean hv_clean firewire_clean \ +clean: acpi_clean cgroup_clean counter_clean cpupower_clean hv_clean firewire_clean \ perf_clean selftests_clean turbostat_clean bootconfig_clean spi_clean usb_clean virtio_clean \ vm_clean bpf_clean iio_clean x86_energy_perf_policy_clean tmon_clean \ freefall_clean build_clean libbpf_clean libsubcmd_clean liblockdep_clean \
tools/counter/Build new file +1 -0
@@ -0,0 +1 @@ +counter_example-y += counter_example.o
tools/counter/Makefile new file +53 -0
53 lines not on this page · raw message
tools/counter/counter_example.c new file +93 -0
93 lines not on this page · raw message
Signature · 1 line
2.32.0
PATCH v13 13/17 counter: Implement signalZ_action_component_id sysfs attribute
In reply to William Breathitt GrayThe Generic Counter chrdev interface expects users to supply component IDs in order to select Synapses for requests. In order for users to know what component ID belongs to which Synapse this information must be exposed. The signalZ_action_component_id attribute provides a way for users to discover what component ID belongs to the respective Synapse.
Cc Gwendal Grignou <[email protected]>
Cc Dan Carpenter <[email protected]>
Reviewed-by David Lechner <[email protected]>
Signed-off-by William Breathitt Gray <[email protected]>
--- Documentation/ABI/testing/sysfs-bus-counter | 7 ++++ drivers/counter/counter-sysfs.c | 46 ++++++++++++++++++++- 2 files changed, 52 insertions(+), 1 deletion(-)
Documentation/ABI/testing/sysfs-bus-counter +7 -0
@@ -203,6 +203,13 @@ Description: both edges: Any state transition. +What: /sys/bus/counter/devices/counterX/countY/signalZ_action_component_id +KernelVersion: 5.15 +Contact: [email protected] +Description: + Read-only attribute that indicates the component ID of the + respective Synapse of Count Y for Signal Z. + What: /sys/bus/counter/devices/counterX/countY/spike_filter_ns KernelVersion: 5.14 Contact: [email protected]
drivers/counter/counter-sysfs.c +45 -1
64 lines not on this page · raw message
Signature · 1 line
2.32.0
PATCH v13 14/17 counter: Implement *_component_id sysfs attributes
In reply to William Breathitt GrayThe Generic Counter chrdev interface expects users to supply component IDs in order to select extensions for requests. In order for users to know what component ID belongs to which extension this information must be exposed. The *_component_id attribute provides a way for users to discover what component ID belongs to which respective extension.
Cc David Lechner <[email protected]>
Cc Gwendal Grignou <[email protected]>
Cc Dan Carpenter <[email protected]>
Signed-off-by William Breathitt Gray <[email protected]>
--- Documentation/ABI/testing/sysfs-bus-counter | 16 +++++++++- drivers/counter/counter-sysfs.c | 33 +++++++++++++++++---- 2 files changed, 42 insertions(+), 7 deletions(-)
Documentation/ABI/testing/sysfs-bus-counter +15 -1
@@ -203,12 +203,26 @@ Description: both edges: Any state transition. +What: /sys/bus/counter/devices/counterX/countY/ceiling_component_id +What: /sys/bus/counter/devices/counterX/countY/floor_component_id +What: /sys/bus/counter/devices/counterX/countY/count_mode_component_id +What: /sys/bus/counter/devices/counterX/countY/direction_component_id +What: /sys/bus/counter/devices/counterX/countY/enable_component_id +What: /sys/bus/counter/devices/counterX/countY/error_noise_component_id +What: /sys/bus/counter/devices/counterX/countY/prescaler_component_id +What: /sys/bus/counter/devices/counterX/countY/preset_component_id +What: /sys/bus/counter/devices/counterX/countY/preset_enable_component_id What: /sys/bus/counter/devices/counterX/countY/signalZ_action_component_id +What: /sys/bus/counter/devices/counterX/signalY/cable_fault_component_id +What: /sys/bus/counter/devices/counterX/signalY/cable_fault_enable_component_id +What: /sys/bus/counter/devices/counterX/signalY/filter_clock_prescaler_component_id +What: /sys/bus/counter/devices/counterX/signalY/index_polarity_component_id +What: /sys/bus/counter/devices/counterX/signalY/synchronous_mode_component_id KernelVersion: 5.15 Contact: [email protected] Description: Read-only attribute that indicates the component ID of the - respective Synapse of Count Y for Signal Z. + respective extension or Synapse. What: /sys/bus/counter/devices/counterX/countY/spike_filter_ns KernelVersion: 5.14
drivers/counter/counter-sysfs.c +27 -6
@@ -588,6 +588,7 @@ static int counter_signal_attrs_create(struct counter_device *const counter,int err;struct counter_comp comp;size_t i; +struct counter_comp *ext;/* Create main Signal attribute */ comp = counter_signal_comp;
@@ -603,8 +604,14 @@ static int counter_signal_attrs_create(struct counter_device *const counter,/* Create an attribute for each extension */ for (i =0 ; i < signal->num_ext; i++) { - err =counter_attr_create (dev, cattr_group, signal->ext + i, - scope, signal); + ext = &signal->ext[i]; + + err =counter_attr_create (dev, cattr_group, ext, scope, signal); +if (err <0 ) +return err; + + err =counter_comp_id_attr_create (dev, cattr_group, ext->name, + i);if (err <0 )return err; }
@@ -695,6 +702,7 @@ static int counter_count_attrs_create(struct counter_device *const counter,int err;struct counter_comp comp;size_t i; +struct counter_comp *ext;/* Create main Count attribute */ comp = counter_count_comp;
@@ -719,8 +727,14 @@ static int counter_count_attrs_create(struct counter_device *const counter,/* Create an attribute for each extension */ for (i =0 ; i < count->num_ext; i++) { - err =counter_attr_create (dev, cattr_group, count->ext + i, - scope, count); + ext = &count->ext[i]; + + err =counter_attr_create (dev, cattr_group, ext, scope, count); +if (err <0 ) +return err; + + err =counter_comp_id_attr_create (dev, cattr_group, ext->name, + i);if (err <0 )return err; }
@@ -784,6 +798,7 @@ static int counter_sysfs_attr_add(struct counter_device *const counter,struct device *const dev = &counter->dev;int err;size_t i; +struct counter_comp *ext;/* Add Signals sysfs attributes */ err =counter_sysfs_signals_add (counter, cattr_group);
@@ -816,8 +831,14 @@ static int counter_sysfs_attr_add(struct counter_device *const counter,/* Create an attribute for each extension */ for (i =0 ; i < counter->num_ext; i++) { - err =counter_attr_create (dev, cattr_group, counter->ext + i, - scope,NULL ); + ext = &counter->ext[i]; + + err =counter_attr_create (dev, cattr_group, ext, scope,NULL ); +if (err <0 ) +return err; + + err =counter_comp_id_attr_create (dev, cattr_group, ext->name, + i);if (err <0 )return err; }
Signature · 1 line
2.32.0
PATCH v13 15/17 counter: Implement events_queue_size sysfs attribute
In reply to William Breathitt GrayThe events_queue_size sysfs attribute provides a way for users to dynamically configure the Counter events queue size for the Counter character device interface. The size is in number of struct counter_event data structures. The number of elements will be rounded-up to a power of 2 due to a requirement of the kfifo_alloc function called during reallocation of the queue.
Cc Oleksij Rempel <[email protected]>
Signed-off-by William Breathitt Gray <[email protected]>
--- Documentation/ABI/testing/sysfs-bus-counter | 8 ++++ drivers/counter/counter-chrdev.c | 6 +++ drivers/counter/counter-sysfs.c | 45 +++++++++++++++++++++ include/linux/counter.h | 2 + 4 files changed, 61 insertions(+)
Documentation/ABI/testing/sysfs-bus-counter +8 -0
@@ -233,6 +233,14 @@ Description: shorter or equal to configured value are ignored. Value 0 means filter is disabled. +What: /sys/bus/counter/devices/counterX/events_queue_size +KernelVersion: 5.15 +Contact: [email protected] +Description: + Size of the Counter events queue in number of struct + counter_event data structures. The number of elements will be + rounded-up to a power of 2. + What: /sys/bus/counter/devices/counterX/name KernelVersion: 5.2 Contact: [email protected]
drivers/counter/counter-chrdev.c +6 -0
@@ -3,6 +3,7 @@* Generic Counter character device interface * Copyright (C) 2020 William Breathitt Gray */ +#include <linux/bitops.h> #include <linux/cdev.h> #include <linux/counter.h> #include <linux/err.h>
@@ -336,6 +337,9 @@ static int counter_chrdev_open(struct inode *inode, struct file *filp)typeof (*counter), chrdev); +if (test_and_set_bit_lock (0 , counter->chrdev_lock)) +return -EBUSY ; +get_device (&counter->dev); filp->private_data = counter;
@@ -352,6 +356,7 @@ static int counter_chrdev_release(struct inode *inode, struct file *filp)return err;put_device (&counter->dev); +clear_bit_unlock (0 , counter->chrdev_lock);return 0 ; }
@@ -376,6 +381,7 @@ int counter_chrdev_add(struct counter_device *const counter)mutex_init (&counter->events_lock);/* Initialize character device */ +clear_bit (0 , counter->chrdev_lock);cdev_init (&counter->chrdev, &counter_fops);/* Allocate Counter events queue */
drivers/counter/counter-sysfs.c +45 -0
74 lines not on this page · raw message
include/linux/counter.h +2 -0
@@ -297,6 +297,7 @@ struct counter_ops {* @events: queue of detected Counter events * @events_wait: wait queue to allow blocking reads of Counter events * @events_lock: lock to protect Counter events queue read operations +* @chrdev_lock: lock to limit chrdev to a single open at a time */ struct counter_device {const char *name;
@@ -323,6 +324,7 @@ struct counter_device { DECLARE_KFIFO_PTR(events, struct counter_event);wait_queue_head_t events_wait;struct mutex events_lock; +DECLARE_BITMAP (chrdev_lock,1 ); };int counter_register (struct counter_device *const counter);
Signature · 1 line
2.32.0
PATCH v13 16/17 counter: 104-quad-8: Replace mutex with spinlock
In reply to William Breathitt GrayThis patch replaces the mutex I/O lock with a spinlock. This is in preparation for a subsequent patch adding IRQ support for 104-QUAD-8 devices; we can't sleep in an interrupt context, so we'll need to use a spinlock instead.
Signed-off-by William Breathitt Gray <[email protected]>
--- drivers/counter/104-quad-8.c | 90 +++++++++++++++++++++--------------- 1 file changed, 53 insertions(+), 37 deletions(-)
drivers/counter/104-quad-8.c +53 -37
@@ -16,6 +16,7 @@#include <linux/module.h> #include <linux/moduleparam.h> #include <linux/types.h> +#include <linux/spinlock.h> #define QUAD8_EXTENT 32
@@ -28,6 +29,7 @@ MODULE_PARM_DESC(base, "ACCES 104-QUAD-8 base addresses");/** * struct quad8 - device private data structure +* @lock: lock to prevent clobbering device states during R/W ops * @counter: instance of the counter_device * @fck_prescaler: array of filter clock prescaler configurations * @preset: array of preset values
@@ -42,7 +44,7 @@ MODULE_PARM_DESC(base, "ACCES 104-QUAD-8 base addresses");* @base: base port address of the device */ struct quad8 { -struct mutex lock; +spinlock_t lock;struct counter_device counter;unsigned int fck_prescaler[QUAD8_NUM_COUNTERS ];unsigned int preset[QUAD8_NUM_COUNTERS ];
@@ -123,6 +125,7 @@ static int quad8_count_read(struct counter_device *counter,unsigned int flags;unsigned int borrow;unsigned int carry; +unsigned long irqflags;int i; flags =inb (base_offset +1 );
@@ -132,7 +135,7 @@ static int quad8_count_read(struct counter_device *counter,/* Borrow XOR Carry effectively doubles count range */ *val = (unsigned long )(borrow ^ carry) <<24 ; -mutex_lock (&priv->lock); +spin_lock_irqsave (&priv->lock, irqflags);/* Reset Byte Pointer; transfer Counter to Output Latch */ outb(QUAD8_CTR_RLD | QUAD8_RLD_RESET_BP | QUAD8_RLD_CNTR_OUT,
@@ -141,7 +144,7 @@ static int quad8_count_read(struct counter_device *counter,for (i =0 ; i <3 ; i++) *val |= (unsigned long )inb (base_offset) << (8 * i); -mutex_unlock (&priv->lock); +spin_unlock_irqrestore (&priv->lock, irqflags);return 0 ; }
@@ -151,13 +154,14 @@ static int quad8_count_write(struct counter_device *counter, {struct quad8 *const priv = counter->priv;const int base_offset = priv->base +2 * count->id; +unsigned long irqflags;int i;/* Only 24-bit values are supported */ if (val >0xFFFFFF )return -ERANGE ; -mutex_lock (&priv->lock); +spin_lock_irqsave (&priv->lock, irqflags);/* Reset Byte Pointer */ outb (QUAD8_CTR_RLD |QUAD8_RLD_RESET_BP , base_offset +1 );
@@ -182,7 +186,7 @@ static int quad8_count_write(struct counter_device *counter,/* Reset Error flag */ outb (QUAD8_CTR_RLD |QUAD8_RLD_RESET_E , base_offset +1 ); -mutex_unlock (&priv->lock); +spin_unlock_irqrestore (&priv->lock, irqflags);return 0 ; }
@@ -200,8 +204,9 @@ static int quad8_function_read(struct counter_device *counter, {struct quad8 *const priv = counter->priv;const int id = count->id; +unsigned long irqflags; -mutex_lock (&priv->lock); +spin_lock_irqsave (&priv->lock, irqflags);if (priv->quadrature_mode[id])switch (priv->quadrature_scale[id]) {
@@ -218,7 +223,7 @@ static int quad8_function_read(struct counter_device *counter,else *function =COUNTER_FUNCTION_PULSE_DIRECTION ; -mutex_unlock (&priv->lock); +spin_unlock_irqrestore (&priv->lock, irqflags);return 0 ; }
@@ -233,10 +238,11 @@ static int quad8_function_write(struct counter_device *counter,unsigned int *const scale = priv->quadrature_scale + id;unsigned int *const synchronous_mode = priv->synchronous_mode + id;const int base_offset = priv->base +2 * id +1 ; +unsigned long irqflags;unsigned int mode_cfg;unsigned int idr_cfg; -mutex_lock (&priv->lock); +spin_lock_irqsave (&priv->lock, irqflags); mode_cfg = priv->count_mode[id] <<1 ; idr_cfg = priv->index_polarity[id] <<1 ;
@@ -271,7 +277,7 @@ static int quad8_function_write(struct counter_device *counter,break ;default :/* should never reach this path */ -mutex_unlock (&priv->lock); +spin_unlock_irqrestore (&priv->lock, irqflags);return -EINVAL ; } }
@@ -279,7 +285,7 @@ static int quad8_function_write(struct counter_device *counter,/* Load mode configuration to Counter Mode Register */ outb (QUAD8_CTR_CMR | mode_cfg, base_offset); -mutex_unlock (&priv->lock); +spin_unlock_irqrestore (&priv->lock, irqflags);return 0 ; }
@@ -405,9 +411,10 @@ static int quad8_index_polarity_set(struct counter_device *counter,struct quad8 *const priv = counter->priv;const size_t channel_id = signal->id -16 ;const int base_offset = priv->base +2 * channel_id +1 ; +unsigned long irqflags;unsigned int idr_cfg = index_polarity <<1 ; -mutex_lock (&priv->lock); +spin_lock_irqsave (&priv->lock, irqflags); idr_cfg |= priv->synchronous_mode[channel_id];
@@ -416,7 +423,7 @@ static int quad8_index_polarity_set(struct counter_device *counter,/* Load Index Control configuration to Index Control Register */ outb (QUAD8_CTR_IDR | idr_cfg, base_offset); -mutex_unlock (&priv->lock); +spin_unlock_irqrestore (&priv->lock, irqflags);return 0 ; }
@@ -445,15 +452,16 @@ static int quad8_synchronous_mode_set(struct counter_device *counter,struct quad8 *const priv = counter->priv;const size_t channel_id = signal->id -16 ;const int base_offset = priv->base +2 * channel_id +1 ; +unsigned long irqflags;unsigned int idr_cfg = synchronous_mode; -mutex_lock (&priv->lock); +spin_lock_irqsave (&priv->lock, irqflags); idr_cfg |= priv->index_polarity[channel_id] <<1 ;/* Index function must be non-synchronous in non-quadrature mode */ if (synchronous_mode && !priv->quadrature_mode[channel_id]) { -mutex_unlock (&priv->lock); +spin_unlock_irqrestore (&priv->lock, irqflags);return -EINVAL ; }
@@ -462,7 +470,7 @@ static int quad8_synchronous_mode_set(struct counter_device *counter,/* Load Index Control configuration to Index Control Register */ outb (QUAD8_CTR_IDR | idr_cfg, base_offset); -mutex_unlock (&priv->lock); +spin_unlock_irqrestore (&priv->lock, irqflags);return 0 ; }
@@ -509,6 +517,7 @@ static int quad8_count_mode_write(struct counter_device *counter,unsigned int count_mode;unsigned int mode_cfg;const int base_offset = priv->base +2 * count->id +1 ; +unsigned long irqflags;/* Map Generic Counter count mode to 104-QUAD-8 count mode */ switch (cnt_mode) {
@@ -529,7 +538,7 @@ static int quad8_count_mode_write(struct counter_device *counter,return -EINVAL ; } -mutex_lock (&priv->lock); +spin_lock_irqsave (&priv->lock, irqflags); priv->count_mode[count->id] = count_mode;
@@ -543,7 +552,7 @@ static int quad8_count_mode_write(struct counter_device *counter,/* Load mode configuration to Counter Mode Register */ outb (QUAD8_CTR_CMR | mode_cfg, base_offset); -mutex_unlock (&priv->lock); +spin_unlock_irqrestore (&priv->lock, irqflags);return 0 ; }
@@ -563,9 +572,10 @@ static int quad8_count_enable_write(struct counter_device *counter, {struct quad8 *const priv = counter->priv;const int base_offset = priv->base +2 * count->id; +unsigned long irqflags;unsigned int ior_cfg; -mutex_lock (&priv->lock); +spin_lock_irqsave (&priv->lock, irqflags); priv->ab_enable[count->id] = enable;
@@ -574,7 +584,7 @@ static int quad8_count_enable_write(struct counter_device *counter,/* Load I/O control configuration */ outb (QUAD8_CTR_IOR | ior_cfg, base_offset +1 ); -mutex_unlock (&priv->lock); +spin_unlock_irqrestore (&priv->lock, irqflags);return 0 ; }
@@ -625,16 +635,17 @@ static int quad8_count_preset_write(struct counter_device *counter, struct counter_count *count, u64 preset) {struct quad8 *const priv = counter->priv; +unsigned long irqflags;/* Only 24-bit values are supported */ if (preset >0xFFFFFF )return -ERANGE ; -mutex_lock (&priv->lock); +spin_lock_irqsave (&priv->lock, irqflags);quad8_preset_register_set (priv, count->id, preset); -mutex_unlock (&priv->lock); +spin_unlock_irqrestore (&priv->lock, irqflags);return 0 ; }
@@ -643,8 +654,9 @@ static int quad8_count_ceiling_read(struct counter_device *counter, struct counter_count *count, u64 *ceiling) { struct quad8 *const priv = counter->priv; +unsigned long irqflags; -mutex_lock (&priv->lock); +spin_lock_irqsave (&priv->lock, irqflags);/* Range Limit and Modulo-N count modes use preset value as ceiling */ switch (priv->count_mode[count->id]) {
@@ -658,7 +670,7 @@ static int quad8_count_ceiling_read(struct counter_device *counter,break ; } -mutex_unlock (&priv->lock); +spin_unlock_irqrestore (&priv->lock, irqflags);return 0 ; }
@@ -667,23 +679,24 @@ static int quad8_count_ceiling_write(struct counter_device *counter, struct counter_count *count, u64 ceiling) {struct quad8 *const priv = counter->priv; +unsigned long irqflags;/* Only 24-bit values are supported */ if (ceiling >0xFFFFFF )return -ERANGE ; -mutex_lock (&priv->lock); +spin_lock_irqsave (&priv->lock, irqflags);/* Range Limit and Modulo-N count modes use preset value as ceiling */ switch (priv->count_mode[count->id]) {case 1 :case 3 :quad8_preset_register_set (priv, count->id, ceiling); -mutex_unlock (&priv->lock); +spin_unlock_irqrestore (&priv->lock, irqflags);return 0 ; } -mutex_unlock (&priv->lock); +spin_unlock_irqrestore (&priv->lock, irqflags);return -EINVAL ; }
@@ -705,12 +718,13 @@ static int quad8_count_preset_enable_write(struct counter_device *counter, {struct quad8 *const priv = counter->priv;const int base_offset = priv->base +2 * count->id +1 ; +unsigned long irqflags;unsigned int ior_cfg;/* Preset enable is active low in Input/Output Control register */ preset_enable = !preset_enable; -mutex_lock (&priv->lock); +spin_lock_irqsave (&priv->lock, irqflags); priv->preset_enable[count->id] = preset_enable;
@@ -719,7 +733,7 @@ static int quad8_count_preset_enable_write(struct counter_device *counter,/* Load I/O control configuration to Input / Output Control Register */ outb (QUAD8_CTR_IOR | ior_cfg, base_offset); -mutex_unlock (&priv->lock); +spin_unlock_irqrestore (&priv->lock, irqflags);return 0 ; }
@@ -730,22 +744,23 @@ static int quad8_signal_cable_fault_read(struct counter_device *counter, {struct quad8 *const priv = counter->priv;const size_t channel_id = signal->id /2 ; +unsigned long irqflags;bool disabled;unsigned int status; -mutex_lock (&priv->lock); +spin_lock_irqsave (&priv->lock, irqflags); disabled = !(priv->cable_fault_enable &BIT (channel_id));if (disabled) { -mutex_unlock (&priv->lock); +spin_unlock_irqrestore (&priv->lock, irqflags);return -EINVAL ; }/* Logic 0 = cable fault */ status =inb (priv->base +QUAD8_DIFF_ENCODER_CABLE_STATUS ); -mutex_unlock (&priv->lock); +spin_unlock_irqrestore (&priv->lock, irqflags);/* Mask respective channel and invert logic */ *cable_fault = !(status &BIT (channel_id));
@@ -771,9 +786,10 @@ static int quad8_signal_cable_fault_enable_write(struct counter_device *counter, {struct quad8 *const priv = counter->priv;const size_t channel_id = signal->id /2 ; +unsigned long irqflags;unsigned int cable_fault_enable; -mutex_lock (&priv->lock); +spin_lock_irqsave (&priv->lock, irqflags);if (enable) priv->cable_fault_enable |=BIT (channel_id);
@@ -785,7 +801,7 @@ static int quad8_signal_cable_fault_enable_write(struct counter_device *counter,outb (cable_fault_enable, priv->base +QUAD8_DIFF_ENCODER_CABLE_STATUS ); -mutex_unlock (&priv->lock); +spin_unlock_irqrestore (&priv->lock, irqflags);return 0 ; }
@@ -808,8 +824,9 @@ static int quad8_signal_fck_prescaler_write(struct counter_device *counter,struct quad8 *const priv = counter->priv;const size_t channel_id = signal->id /2 ;const int base_offset = priv->base +2 * channel_id; +unsigned long irqflags; -mutex_lock (&priv->lock); +spin_lock_irqsave (&priv->lock, irqflags); priv->fck_prescaler[channel_id] = prescaler;
@@ -821,7 +838,7 @@ static int quad8_signal_fck_prescaler_write(struct counter_device *counter,outb (QUAD8_CTR_RLD |QUAD8_RLD_RESET_BP |QUAD8_RLD_PRESET_PSC , base_offset +1 ); -mutex_unlock (&priv->lock); +spin_unlock_irqrestore (&priv->lock, irqflags);return 0 ; }
@@ -990,8 +1007,7 @@ static int quad8_probe(struct device *dev, unsigned int id) priv->counter.priv = priv; priv->base = base[id]; -/* Initialize mutex */ -mutex_init (&priv->lock); +spin_lock_init (&priv->lock);/* Reset all counters and disable interrupt function */ outb (QUAD8_CHAN_OP_RESET_COUNTERS , base[id] +QUAD8_REG_CHAN_OP );
Signature · 1 line
2.32.0
PATCH v13 17/17 counter: 104-quad-8: Add IRQ support for the ACCES 104-QUAD-8
In reply to William Breathitt GrayThe LSI/CSI LS7266R1 chip provides programmable output via the FLG pins. When interrupts are enabled on the ACCES 104-QUAD-8, they occur whenever FLG1 is active. Four functions are available for the FLG1 signal: Carry, Compare, Carry-Borrow, and Index.
Carry:
Interrupt generated on active low Carry signal. Carry signal toggles every time the respective channel's counter overflows.
Compare:
Interrupt generated on active low Compare signal. Compare signal toggles every time respective channel's preset register is equal to the respective channel's counter.
Carry-Borrow:
Interrupt generated on active low Carry signal and active low Borrow signal. Carry signal toggles every time the respective channel's counter overflows. Borrow signal toggles every time the respective channel's counter underflows.
Index:
Interrupt generated on active high Index signal.
These four functions correspond respectivefly to the following four Counter event types: COUNTER_EVENT_OVERFLOW, COUNTER_EVENT_THRESHOLD, COUNTER_EVENT_OVERFLOW_UNDERFLOW, and COUNTER_EVENT_INDEX. Interrupts push Counter events to event channel X, where 'X' is the respective channel whose FLG1 activated.
This patch adds IRQ support for the ACCES 104-QUAD-8. The interrupt line numbers for the devices may be configured via the irq array module parameter.
Signed-off-by William Breathitt Gray <[email protected]>
--- drivers/counter/104-quad-8.c | 167 +++++++++++++++++++++++++++++++++-- drivers/counter/Kconfig | 6 +- 2 files changed, 164 insertions(+), 9 deletions(-)
drivers/counter/104-quad-8.c +161 -6
@@ -11,6 +11,7 @@#include <linux/errno.h> #include <linux/io.h> #include <linux/ioport.h> +#include <linux/interrupt.h> #include <linux/isa.h> #include <linux/kernel.h> #include <linux/module.h>
@@ -25,6 +26,10 @@ static unsigned int num_quad8;module_param_hw_array (base, uint, ioport, &num_quad8,0 );MODULE_PARM_DESC (base,"ACCES 104-QUAD-8 base addresses" ); +static unsigned int irq[max_num_isa_dev (QUAD8_EXTENT )]; +module_param_hw_array (irq, uint, irq,NULL ,0 ); +MODULE_PARM_DESC (irq,"ACCES 104-QUAD-8 interrupt line numbers" ); +#define QUAD8_NUM_COUNTERS 8/**
@@ -38,6 +43,8 @@ MODULE_PARM_DESC(base, "ACCES 104-QUAD-8 base addresses");* @quadrature_scale: array of quadrature mode scale configurations * @ab_enable: array of A and B inputs enable configurations * @preset_enable: array of set_to_preset_on_index attribute configurations +* @irq_trigger: array of current IRQ trigger function configurations +* @next_irq_trigger: array of next IRQ trigger function configurations * @synchronous_mode: array of index function synchronous mode configurations * @index_polarity: array of index function polarity configurations * @cable_fault_enable: differential encoder cable status enable configurations
@@ -53,13 +60,17 @@ struct quad8 {unsigned int quadrature_scale[QUAD8_NUM_COUNTERS ];unsigned int ab_enable[QUAD8_NUM_COUNTERS ];unsigned int preset_enable[QUAD8_NUM_COUNTERS ]; +unsigned int irq_trigger[QUAD8_NUM_COUNTERS ]; +unsigned int next_irq_trigger[QUAD8_NUM_COUNTERS ];unsigned int synchronous_mode[QUAD8_NUM_COUNTERS ];unsigned int index_polarity[QUAD8_NUM_COUNTERS ];unsigned int cable_fault_enable;unsigned int base; }; +#define QUAD8_REG_INTERRUPT_STATUS 0x10#define QUAD8_REG_CHAN_OP 0x11 +#define QUAD8_REG_INDEX_INTERRUPT 0x12#define QUAD8_REG_INDEX_INPUT_LEVELS 0x16#define QUAD8_DIFF_ENCODER_CABLE_STATUS 0x17/* Borrow Toggle flip-flop */
@@ -92,8 +103,8 @@ struct quad8 {#define QUAD8_RLD_CNTR_OUT 0x10/* Transfer Preset Register LSB to FCK Prescaler */ #define QUAD8_RLD_PRESET_PSC 0x18 -#define QUAD8_CHAN_OP_ENABLE_COUNTERS 0x00#define QUAD8_CHAN_OP_RESET_COUNTERS 0x01 +#define QUAD8_CHAN_OP_ENABLE_INTERRUPT_FUNC 0x04#define QUAD8_CMR_QUADRATURE_X1 0x08#define QUAD8_CMR_QUADRATURE_X2 0x10#define QUAD8_CMR_QUADRATURE_X4 0x18
@@ -378,13 +389,103 @@ static int quad8_action_read(struct counter_device *counter, } } +enum { +QUAD8_EVENT_NONE =-1 , +QUAD8_EVENT_CARRY =0 , +QUAD8_EVENT_COMPARE =1 , +QUAD8_EVENT_CARRY_BORROW =2 , +QUAD8_EVENT_INDEX =3 , +}; + +static int quad8_events_configure (struct counter_device *counter) +{ +struct quad8 *const priv = counter->priv; +unsigned long irq_enabled =0 ; +unsigned long irqflags; +size_t channel; +unsigned long ior_cfg; +unsigned long base_offset; + +spin_lock_irqsave (&priv->lock, irqflags); + +/* Enable interrupts for the requested channels, disable for the rest */ +for (channel =0 ; channel <QUAD8_NUM_COUNTERS ; channel++) { +if (priv->next_irq_trigger[channel] ==QUAD8_EVENT_NONE ) +continue ; + +if (priv->irq_trigger[channel] != priv->next_irq_trigger[channel]) { +/* Save new IRQ function configuration */ + priv->irq_trigger[channel] = priv->next_irq_trigger[channel]; + +/* Load configuration to I/O Control Register */ + ior_cfg = priv->ab_enable[channel] | + priv->preset_enable[channel] <<1 | + priv->irq_trigger[channel] <<3 ; + base_offset = priv->base +2 * channel +1 ; +outb (QUAD8_CTR_IOR | ior_cfg, base_offset); + } + +/* Reset next IRQ trigger function configuration */ + priv->next_irq_trigger[channel] =QUAD8_EVENT_NONE ; + +/* Enable IRQ line */ + irq_enabled |=BIT (channel); + } + +outb (irq_enabled, priv->base +QUAD8_REG_INDEX_INTERRUPT ); + +spin_unlock_irqrestore (&priv->lock, irqflags); + +return 0 ; +} + +static int quad8_watch_validate (struct counter_device *counter, +const struct counter_watch *watch) +{ +struct quad8 *const priv = counter->priv; + +if (watch->channel >QUAD8_NUM_COUNTERS -1 ) +return -EINVAL ; + +switch (watch->event) { +case COUNTER_EVENT_OVERFLOW : +if (priv->next_irq_trigger[watch->channel] ==QUAD8_EVENT_NONE ) + priv->next_irq_trigger[watch->channel] =QUAD8_EVENT_CARRY ; +else if (priv->next_irq_trigger[watch->channel] !=QUAD8_EVENT_CARRY ) +return -EINVAL ; +return 0 ; +case COUNTER_EVENT_THRESHOLD : +if (priv->next_irq_trigger[watch->channel] ==QUAD8_EVENT_NONE ) + priv->next_irq_trigger[watch->channel] =QUAD8_EVENT_COMPARE ; +else if (priv->next_irq_trigger[watch->channel] !=QUAD8_EVENT_COMPARE ) +return -EINVAL ; +return 0 ; +case COUNTER_EVENT_OVERFLOW_UNDERFLOW : +if (priv->next_irq_trigger[watch->channel] ==QUAD8_EVENT_NONE ) + priv->next_irq_trigger[watch->channel] =QUAD8_EVENT_CARRY_BORROW ; +else if (priv->next_irq_trigger[watch->channel] !=QUAD8_EVENT_CARRY_BORROW ) +return -EINVAL ; +return 0 ; +case COUNTER_EVENT_INDEX : +if (priv->next_irq_trigger[watch->channel] ==QUAD8_EVENT_NONE ) + priv->next_irq_trigger[watch->channel] =QUAD8_EVENT_INDEX ; +else if (priv->next_irq_trigger[watch->channel] !=QUAD8_EVENT_INDEX ) +return -EINVAL ; +return 0 ; +default : +return -EINVAL ; + } +} +static const struct counter_ops quad8_ops = { .signal_read = quad8_signal_read, .count_read = quad8_count_read, .count_write = quad8_count_write, .function_read = quad8_function_read, .function_write = quad8_function_write, - .action_read = quad8_action_read + .action_read = quad8_action_read, + .events_configure = quad8_events_configure, + .watch_validate = quad8_watch_validate, };static const char *const quad8_index_polarity_modes[] = {
@@ -579,7 +680,8 @@ static int quad8_count_enable_write(struct counter_device *counter, priv->ab_enable[count->id] = enable; - ior_cfg = enable | priv->preset_enable[count->id] <<1 ; + ior_cfg = enable | priv->preset_enable[count->id] <<1 | + priv->irq_trigger[count->id] <<3 ;/* Load I/O control configuration */ outb (QUAD8_CTR_IOR | ior_cfg, base_offset +1 );
@@ -728,7 +830,8 @@ static int quad8_count_preset_enable_write(struct counter_device *counter, priv->preset_enable[count->id] = preset_enable; - ior_cfg = priv->ab_enable[count->id] | preset_enable <<1 ; + ior_cfg = priv->ab_enable[count->id] | preset_enable <<1 | + priv->irq_trigger[count->id] <<3 ;/* Load I/O control configuration to Input / Output Control Register */ outb (QUAD8_CTR_IOR | ior_cfg, base_offset);
@@ -980,11 +1083,54 @@ static struct counter_count quad8_counts[] = {QUAD8_COUNT (7 ,"Channel 8 Count" ) }; +static irqreturn_t quad8_irq_handler (int irq,void *private) +{ +struct quad8 *const priv = private; +const unsigned long base = priv->base; +unsigned long irq_status; +unsigned long channel; +u8 event; + + irq_status =inb (base +QUAD8_REG_INTERRUPT_STATUS ); +if (!irq_status) +return IRQ_NONE ; + +for_each_set_bit (channel, &irq_status,QUAD8_NUM_COUNTERS ) { +switch (priv->irq_trigger[channel]) { +case QUAD8_EVENT_CARRY : + event =COUNTER_EVENT_OVERFLOW ; +break ; +case QUAD8_EVENT_COMPARE : + event =COUNTER_EVENT_THRESHOLD ; +break ; +case QUAD8_EVENT_CARRY_BORROW : + event =COUNTER_EVENT_OVERFLOW_UNDERFLOW ; +break ; +case QUAD8_EVENT_INDEX : + event =COUNTER_EVENT_INDEX ; +break ; +default : +/* should never reach this path */ +WARN_ONCE (true,"invalid interrupt trigger function %u configured for channel %lu\n" , + priv->irq_trigger[channel], channel); +continue ; + } + +counter_push_event (&priv->counter, event, channel); + } + +/* Clear pending interrupts on device */ +outb (QUAD8_CHAN_OP_ENABLE_INTERRUPT_FUNC , base +QUAD8_REG_CHAN_OP ); + +return IRQ_HANDLED ; +} +static int quad8_probe (struct device *dev,unsigned int id) {struct quad8 *priv;int i, j;unsigned int base_offset; +int err;if (!devm_request_region (dev, base[id],QUAD8_EXTENT ,dev_name (dev))) { dev_err(dev, "Unable to lock port addresses (0x%X-0x%X)\n",
@@ -1009,6 +1155,8 @@ static int quad8_probe(struct device *dev, unsigned int id)spin_lock_init (&priv->lock); +/* Reset Index/Interrupt Register */ +outb (0x00 , base[id] +QUAD8_REG_INDEX_INTERRUPT );/* Reset all counters and disable interrupt function */ outb (QUAD8_CHAN_OP_RESET_COUNTERS , base[id] +QUAD8_REG_CHAN_OP );/* Set initial configuration for all counters */
@@ -1035,11 +1183,18 @@ static int quad8_probe(struct device *dev, unsigned int id)outb (QUAD8_CTR_IOR , base_offset +1 );/* Disable index function; negative index polarity */ outb (QUAD8_CTR_IDR , base_offset +1 ); +/* Initialize next IRQ trigger function configuration */ + priv->next_irq_trigger[i] =QUAD8_EVENT_NONE ; }/* Disable Differential Encoder Cable Status for all channels */ outb (0xFF , base[id] +QUAD8_DIFF_ENCODER_CABLE_STATUS ); -/* Enable all counters */ -outb (QUAD8_CHAN_OP_ENABLE_COUNTERS , base[id] +QUAD8_REG_CHAN_OP ); +/* Enable all counters and enable interrupt function */ +outb (QUAD8_CHAN_OP_ENABLE_INTERRUPT_FUNC , base[id] +QUAD8_REG_CHAN_OP ); + + err =devm_request_irq (dev, irq[id], quad8_irq_handler,IRQF_SHARED , + priv->counter.name, priv); +if (err) +return err;return devm_counter_register (dev, &priv->counter); }
drivers/counter/Kconfig +3 -3
@@ -23,11 +23,11 @@ config 104_QUAD_8 A counter's respective error flag may be cleared by performing a write operation on the respective count value attribute. Although the 104-QUAD-8 counters have a 25-bit range, only the lower 24 bits may be - set, either directly or via the counter's preset attribute. Interrupts - are not supported by this driver. + set, either directly or via the counter's preset attribute. The base port addresses for the devices may be configured via the base - array module parameter. + array module parameter. The interrupt line numbers for the devices may + be configured via the irq array module parameter. config INTERRUPT_CNT tristate "Interrupt counter driver"
Signature · 1 line
2.32.0
Quoted 67 lines · William Breathitt Gray
Suppose I open the chrdev from a userspace application and keep it open, but then remove the respective driver and Counter subsystem module from my system. The
devm_counter_release()andcounter_exit()functions will be called as expected; thecounter_chrdev_release()function will not be called yet, but that is expected because the chrdev is still open by userspace. If I try to break out of my userspace application, I expectcounter_chrdev_release()to finally be called, but this does not happen. Instead, my userspace application stalls and I see the following error in my dmesg:[ 172.859570] BUG: unable to handle page fault for address: ffffffffc09ae298 [ 172.859594] #PF: supervisor read access in kernel mode [ 172.859598] #PF: error_code(0x0000) - not-present page [ 172.859603] PGD 23615067 P4D 23615067 PUD 23617067 PMD 1029ad067 PTE 0 [ 172.859623] Oops: 0000 [#1] SMP NOPTI [ 172.859629] CPU: 2 PID: 2485 Comm: counter_example Not tainted 5.13.0+ #1 [ 172.859640] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS d55cb5a 04/01/2014 [ 172.859645] RIP: 0010:filp_close+0x29/0x70 [ 172.859662] Code: 90 0f 1f 44 00 00 55 48 89 e5 41 56 41 55 41 54 48 8b 47 38 48 85 c0 0f 84 b7 40 86 00 48 8b 47 28 49 89 fc 49 89 f5 45 31 f6 <48> 8b 40 78 48 85 c0 74 08 ff d0 0f 1f 00 41 89 c6 41 f6 44 24 45 [ 172.859669] RSP: 0018:ffffad31c0ee7cb0 EFLAGS: 00010246 [ 172.859675] RAX: ffffffffc09ae220 RBX: 0000000000000001 RCX: 0000000000000001 [ 172.859680] RDX: ffff9a43829708e0 RSI: ffff9a4382970840 RDI: ffff9a43821f4f00 [ 172.859684] RBP: ffffad31c0ee7cc8 R08: 0000000000000001 R09: 0000000000000001 [ 172.859687] R10: ffffffffffff4d00 R11: ffff9a43933c6e10 R12: ffff9a43821f4f00 [ 172.859691] R13: ffff9a4382970840 R14: 0000000000000000 R15: 0000000000000003 [ 172.859694] FS: 0000000000000000(0000) GS:ffff9a44b7d00000(0000) knlGS:0000000000000000 [ 172.859699] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 172.859704] CR2: ffffffffc09ae298 CR3: 0000000023610001 CR4: 0000000000370ee0 [ 172.859713] Call Trace: [ 172.859730] put_files_struct+0x73/0xd0 [ 172.859738] exit_files+0x49/0x50 [ 172.859743] do_exit+0x33b/0xa20 [ 172.859751] do_group_exit+0x3b/0xb0 [ 172.859758] get_signal+0x16f/0x8b0 [ 172.859766] ? _copy_to_user+0x20/0x30 [ 172.859774] ? put_timespec64+0x3d/0x60 [ 172.859784] arch_do_signal_or_restart+0xf3/0x850 [ 172.859794] ? hrtimer_nanosleep+0x9f/0x120 [ 172.859802] ? __hrtimer_init+0xd0/0xd0 [ 172.859808] exit_to_user_mode_prepare+0x122/0x1b0 [ 172.859816] syscall_exit_to_user_mode+0x27/0x50 [ 172.859825] do_syscall_64+0x48/0xc0 [ 172.859831] entry_SYSCALL_64_after_hwframe+0x44/0xae [ 172.859839] RIP: 0033:0x7f07f8b9951a [ 172.859850] Code: Unable to access opcode bytes at RIP 0x7f07f8b994f0. [ 172.859853] RSP: 002b:00007ffc0d12c230 EFLAGS: 00000246 ORIG_RAX: 00000000000000e6 [ 172.859860] RAX: fffffffffffffdfc RBX: ffffffffffffff01 RCX: 00007f07f8b9951a [ 172.859863] RDX: 00007ffc0d12c2b0 RSI: 0000000000000000 RDI: 0000000000000000 [ 172.859867] RBP: 0000000000000000 R08: 0000000000000000 R09: 00007ffc0d12c1c6 [ 172.859871] R10: 00007ffc0d12c2b0 R11: 0000000000000246 R12: 00007ffc0d12c2b0 [ 172.859874] R13: 00007ffc0d12c2b0 R14: 0000000000000000 R15: 0000000000000000 [ 172.859886] Modules linked in: intel_rapl_msr intel_rapl_common kvm_intel kvm crct10dif_pclmul crc32_pclmul ghash_clmulni_intel nls_iso8859_1 aesni_intel crypto_simd cryptd rapl drm_ttm_helper ttm uvcvideo drm_kms_helper videobuf2_vmalloc videobuf2_memops videobuf2_v4l2 videobuf2_common input_leds syscopyarea videodev sysfillrect sysimgblt fb_sys_fops cec rc_core joydev mc drm serio_raw mac_hid qemu_fw_cfg sch_fq_codel msr parport_pc ppdev lp parport virtio_rng ip_tables x_tables autofs4 hid_generic usbhid hid virtio_net psmouse net_failover i2c_piix4 virtio_blk failover pata_acpi floppy [last unloaded: counter] [ 172.859995] CR2: ffffffffc09ae298 [ 172.860009] ---[ end trace e7d3d7da1a73b8f4 ]--- [ 172.860013] RIP: 0010:filp_close+0x29/0x70 [ 172.860021] Code: 90 0f 1f 44 00 00 55 48 89 e5 41 56 41 55 41 54 48 8b 47 38 48 85 c0 0f 84 b7 40 86 00 48 8b 47 28 49 89 fc 49 89 f5 45 31 f6 <48> 8b 40 78 48 85 c0 74 08 ff d0 0f 1f 00 41 89 c6 41 f6 44 24 45 [ 172.860027] RSP: 0018:ffffad31c0ee7cb0 EFLAGS: 00010246 [ 172.860031] RAX: ffffffffc09ae220 RBX: 0000000000000001 RCX: 0000000000000001 [ 172.860034] RDX: ffff9a43829708e0 RSI: ffff9a4382970840 RDI: ffff9a43821f4f00 [ 172.860038] RBP: ffffad31c0ee7cc8 R08: 0000000000000001 R09: 0000000000000001 [ 172.860041] R10: ffffffffffff4d00 R11: ffff9a43933c6e10 R12: ffff9a43821f4f00 [ 172.860044] R13: ffff9a4382970840 R14: 0000000000000000 R15: 0000000000000003 [ 172.860047] FS: 0000000000000000(0000) GS:ffff9a44b7d00000(0000) knlGS:0000000000000000 [ 172.860052] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 172.860056] CR2: ffffffffc09ae298 CR3: 0000000023610001 CR4: 0000000000370ee0 [ 172.860073] Fixing recursive fault but reboot is needed!
Quoted 3 lines
It looks like faults in
filp_close()beforecounter_chrdev_release()is called. Is this issue manifesting becausecounter_exit()was called earlier while the chrdev was still open?
After giving this some more thought I realized that once the counter module is unloaded, the counter_fops callbacks are lost and thus the fops for the chrdev are no longer be valid. This means that counter_chrdev_release will need to be called before the counter module is unloaded. How can I guarantee this if a userspace application may still have the chrdev indefinitely open? In counter_chrdev_remove(), should I walk through the open chrdevs and release each one?
William Breathitt Gray
Quoted 80 lines · William Breathitt Gray
Quoted 67 lines · William Breathitt Gray
Suppose I open the chrdev from a userspace application and keep it open, but then remove the respective driver and Counter subsystem module from my system. The
devm_counter_release()andcounter_exit()functions will be called as expected; thecounter_chrdev_release()function will not be called yet, but that is expected because the chrdev is still open by userspace. If I try to break out of my userspace application, I expectcounter_chrdev_release()to finally be called, but this does not happen. Instead, my userspace application stalls and I see the following error in my dmesg:[ 172.859570] BUG: unable to handle page fault for address: ffffffffc09ae298 [ 172.859594] #PF: supervisor read access in kernel mode [ 172.859598] #PF: error_code(0x0000) - not-present page [ 172.859603] PGD 23615067 P4D 23615067 PUD 23617067 PMD 1029ad067 PTE 0 [ 172.859623] Oops: 0000 [#1] SMP NOPTI [ 172.859629] CPU: 2 PID: 2485 Comm: counter_example Not tainted 5.13.0+ #1 [ 172.859640] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS d55cb5a 04/01/2014 [ 172.859645] RIP: 0010:filp_close+0x29/0x70 [ 172.859662] Code: 90 0f 1f 44 00 00 55 48 89 e5 41 56 41 55 41 54 48 8b 47 38 48 85 c0 0f 84 b7 40 86 00 48 8b 47 28 49 89 fc 49 89 f5 45 31 f6 <48> 8b 40 78 48 85 c0 74 08 ff d0 0f 1f 00 41 89 c6 41 f6 44 24 45 [ 172.859669] RSP: 0018:ffffad31c0ee7cb0 EFLAGS: 00010246 [ 172.859675] RAX: ffffffffc09ae220 RBX: 0000000000000001 RCX: 0000000000000001 [ 172.859680] RDX: ffff9a43829708e0 RSI: ffff9a4382970840 RDI: ffff9a43821f4f00 [ 172.859684] RBP: ffffad31c0ee7cc8 R08: 0000000000000001 R09: 0000000000000001 [ 172.859687] R10: ffffffffffff4d00 R11: ffff9a43933c6e10 R12: ffff9a43821f4f00 [ 172.859691] R13: ffff9a4382970840 R14: 0000000000000000 R15: 0000000000000003 [ 172.859694] FS: 0000000000000000(0000) GS:ffff9a44b7d00000(0000) knlGS:0000000000000000 [ 172.859699] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 172.859704] CR2: ffffffffc09ae298 CR3: 0000000023610001 CR4: 0000000000370ee0 [ 172.859713] Call Trace: [ 172.859730] put_files_struct+0x73/0xd0 [ 172.859738] exit_files+0x49/0x50 [ 172.859743] do_exit+0x33b/0xa20 [ 172.859751] do_group_exit+0x3b/0xb0 [ 172.859758] get_signal+0x16f/0x8b0 [ 172.859766] ? _copy_to_user+0x20/0x30 [ 172.859774] ? put_timespec64+0x3d/0x60 [ 172.859784] arch_do_signal_or_restart+0xf3/0x850 [ 172.859794] ? hrtimer_nanosleep+0x9f/0x120 [ 172.859802] ? __hrtimer_init+0xd0/0xd0 [ 172.859808] exit_to_user_mode_prepare+0x122/0x1b0 [ 172.859816] syscall_exit_to_user_mode+0x27/0x50 [ 172.859825] do_syscall_64+0x48/0xc0 [ 172.859831] entry_SYSCALL_64_after_hwframe+0x44/0xae [ 172.859839] RIP: 0033:0x7f07f8b9951a [ 172.859850] Code: Unable to access opcode bytes at RIP 0x7f07f8b994f0. [ 172.859853] RSP: 002b:00007ffc0d12c230 EFLAGS: 00000246 ORIG_RAX: 00000000000000e6 [ 172.859860] RAX: fffffffffffffdfc RBX: ffffffffffffff01 RCX: 00007f07f8b9951a [ 172.859863] RDX: 00007ffc0d12c2b0 RSI: 0000000000000000 RDI: 0000000000000000 [ 172.859867] RBP: 0000000000000000 R08: 0000000000000000 R09: 00007ffc0d12c1c6 [ 172.859871] R10: 00007ffc0d12c2b0 R11: 0000000000000246 R12: 00007ffc0d12c2b0 [ 172.859874] R13: 00007ffc0d12c2b0 R14: 0000000000000000 R15: 0000000000000000 [ 172.859886] Modules linked in: intel_rapl_msr intel_rapl_common kvm_intel kvm crct10dif_pclmul crc32_pclmul ghash_clmulni_intel nls_iso8859_1 aesni_intel crypto_simd cryptd rapl drm_ttm_helper ttm uvcvideo drm_kms_helper videobuf2_vmalloc videobuf2_memops videobuf2_v4l2 videobuf2_common input_leds syscopyarea videodev sysfillrect sysimgblt fb_sys_fops cec rc_core joydev mc drm serio_raw mac_hid qemu_fw_cfg sch_fq_codel msr parport_pc ppdev lp parport virtio_rng ip_tables x_tables autofs4 hid_generic usbhid hid virtio_net psmouse net_failover i2c_piix4 virtio_blk failover pata_acpi floppy [last unloaded: counter] [ 172.859995] CR2: ffffffffc09ae298 [ 172.860009] ---[ end trace e7d3d7da1a73b8f4 ]--- [ 172.860013] RIP: 0010:filp_close+0x29/0x70 [ 172.860021] Code: 90 0f 1f 44 00 00 55 48 89 e5 41 56 41 55 41 54 48 8b 47 38 48 85 c0 0f 84 b7 40 86 00 48 8b 47 28 49 89 fc 49 89 f5 45 31 f6 <48> 8b 40 78 48 85 c0 74 08 ff d0 0f 1f 00 41 89 c6 41 f6 44 24 45 [ 172.860027] RSP: 0018:ffffad31c0ee7cb0 EFLAGS: 00010246 [ 172.860031] RAX: ffffffffc09ae220 RBX: 0000000000000001 RCX: 0000000000000001 [ 172.860034] RDX: ffff9a43829708e0 RSI: ffff9a4382970840 RDI: ffff9a43821f4f00 [ 172.860038] RBP: ffffad31c0ee7cc8 R08: 0000000000000001 R09: 0000000000000001 [ 172.860041] R10: ffffffffffff4d00 R11: ffff9a43933c6e10 R12: ffff9a43821f4f00 [ 172.860044] R13: ffff9a4382970840 R14: 0000000000000000 R15: 0000000000000003 [ 172.860047] FS: 0000000000000000(0000) GS:ffff9a44b7d00000(0000) knlGS:0000000000000000 [ 172.860052] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 172.860056] CR2: ffffffffc09ae298 CR3: 0000000023610001 CR4: 0000000000370ee0 [ 172.860073] Fixing recursive fault but reboot is needed!Quoted 3 lines
It looks like faults in
filp_close()beforecounter_chrdev_release()is called. Is this issue manifesting becausecounter_exit()was called earlier while the chrdev was still open?After giving this some more thought I realized that once the counter module is unloaded, the
counter_fopscallbacks are lost and thus the fops for the chrdev are no longer be valid. This means thatcounter_chrdev_releasewill need to be called before the counter module is unloaded. How can I guarantee this if a userspace application may still have the chrdev indefinitely open? Incounter_chrdev_remove(), should I walk through the open chrdevs and release each one?
Quoted 1 line
William Breathitt Gray
Sorry for all the noise, I had simply forgotten to define the owner member of counter_fops structure to THIS_MODULE. I'll make that fix and also add in some conditional checks to protect the callbacks so they return -ENODEV if the counter has been unregistered. With that I expect to have a v14 submission ready some time this coming week.
William Breathitt Gray