Input: Add I2C attached EETI EXC3000 multi touch driver
Subsystems (3)
PATCH 1/1 Input: Add I2C attached EETI EXC3000 multi touch driver
The 3000 series have a new protocol which allows to report up to 5 points in a single 66 byte frame. One must always read in 66 byte frames. To support up to 10 points, two consecutive frames need to be read:
The first frame says how many points until sync.
The second frame must say zero points or be discarded.
To be able to work with the higher 400KHz I2C bus rate, one must successfully send a special package prior _each_ read or the controller will refuse to cooperate.
It is important not to rely on the i2c_master_recv return value:
Ignoring failed transfers sometimes causes hanging touch events, as the controller thinks that the transfer succeeded and won't resend the event.
This is a minimal implementation based on egalax_i2c.c (which can be found on the internet) and egalax_ts.c but without the vendor interface and no power management support.
--- .../bindings/input/touchscreen/exc3000.txt | 18 +++ drivers/input/touchscreen/Kconfig | 10 ++ drivers/input/touchscreen/Makefile | 1 + drivers/input/touchscreen/exc3000.c | 154 +++++++++++++++++++++ 4 files changed, 183 insertions(+) create mode 100644 Documentation/devicetree/bindings/input/touchscreen/exc3000.txt create mode 100644 drivers/input/touchscreen/exc3000.c
Documentation/devicetree/bindings/input/touchscreen/exc3000.txt new file +18 -0
@@ -0,0 +1,18 @@ +* EETI EXC3000 Multiple Touch Controller + +Required properties: +- compatible: must be "eeti,exc3000" +- reg: i2c slave address +- interrupt-parent: the phandle for the interrupt controller +- interrupts: touch controller interrupt +- irq-gpios: the gpio pin to be used as irq pin + +Example: + + exc3000@2a { + compatible = "eeti,exc3000"; + reg = <0x2a>; + interrupt-parent = <&gpio1>; + interrupts = <9 2>; + irq-gpios = <&gpio1 9 0>; + };
drivers/input/touchscreen/Kconfig +10 -0
@@ -314,6 +314,16 @@ config TOUCHSCREEN_EGALAX_SERIAL To compile this driver as a module, choose M here: the module will be called egalax_ts_serial. +config TOUCHSCREEN_EXC3000 + tristate "EETI EXC3000 multi-touch panel support" + depends on I2C + help + Say Y here to enable support for I2C connected EETI + EXC3000 multi-touch panels. + + To compile this driver as a module, choose M here: the + module will be called exc3000. + config TOUCHSCREEN_FUJITSU tristate "Fujitsu serial touchscreen" select SERIO
drivers/input/touchscreen/Makefile +1 -0
@@ -38,6 +38,7 @@ obj-$(CONFIG_TOUCHSCREEN_ELAN) += elants_i2c.o obj-$(CONFIG_TOUCHSCREEN_ELO) += elo.o obj-$(CONFIG_TOUCHSCREEN_EGALAX) += egalax_ts.o obj-$(CONFIG_TOUCHSCREEN_EGALAX_SERIAL) += egalax_ts_serial.o +obj-$(CONFIG_TOUCHSCREEN_EXC3000) += exc3000.o obj-$(CONFIG_TOUCHSCREEN_FUJITSU) += fujitsu_ts.o obj-$(CONFIG_TOUCHSCREEN_GOODIX) += goodix.o obj-$(CONFIG_TOUCHSCREEN_ILI210X) += ili210x.o
drivers/input/touchscreen/exc3000.c new file +154 -0
154 lines not on this page · raw message
Signature · 1 line
2.11.0
Dmitry Torokhov
maintainerHi Ahmet,
Quoted 6 lines · Ahmet Inan
The 3000 series have a new protocol which allows to report up to 5 points in a single 66 byte frame. One must always read in 66 byte frames. To support up to 10 points, two consecutive frames need to be read:
The first frame says how many points until sync.
The second frame must say zero points or be discarded.
Quoted 7 lines
To be able to work with the higher 400KHz I2C bus rate, one must successfully send a special package prior _each_ read or the controller will refuse to cooperate.
It is important not to rely on the
i2c_master_recvreturn value:
Ignoring failed transfers sometimes causes hanging touch events, as the controller thinks that the transfer succeeded and won't resend the event.
This statement worries me, because you are basically end up reporting garbage. Does the controller sends all active contacts in each frame, or only changed ones? You can use INPUT_MT_DROP_UNUSED to let input core automatically drop contacts that were not reported within the last frame. And fire up a timer to release everything if last transfer errors out.
Quoted 89 lines
This is a minimal implementation based on
egalax_i2c.c(which can be found on the internet) andegalax_ts.cbut without the vendor interface and no power management support.Signed-off-by Ahmet Inan <[email protected]>--- .../bindings/input/touchscreen/exc3000.txt | 18 +++ drivers/input/touchscreen/Kconfig | 10 ++ drivers/input/touchscreen/Makefile | 1 + drivers/input/touchscreen/exc3000.c | 154 +++++++++++++++++++++ 4 files changed, 183 insertions(+) create mode 100644 Documentation/devicetree/bindings/input/touchscreen/exc3000.txt create mode 100644 drivers/input/touchscreen/exc3000.cDocumentation/devicetree/bindings/input/touchscreen/exc3000.txt new file +18
-0@@ -0,0 +1,18 @@ +* EETI EXC3000 Multiple Touch Controller + +Required properties: +- compatible: must be "eeti,exc3000" +- reg: i2c slave address +- interrupt-parent: the phandle for the interrupt controller +- interrupts: touch controller interrupt +- irq-gpios: the gpio pin to be used as irq pin + +Example: + + exc3000@2a { + compatible = "eeti,exc3000"; + reg = <0x2a>; + interrupt-parent = <&gpio1>; + interrupts = <9 2>; + irq-gpios = <&gpio1 9 0>; + };drivers/input/touchscreen/Kconfig +10
-0@@ -314,6 +314,16 @@ config TOUCHSCREEN_EGALAX_SERIAL To compile this driver as a module, choose M here: the module will be called egalax_ts_serial. +config TOUCHSCREEN_EXC3000 + tristate "EETI EXC3000 multi-touch panel support" + depends on I2C + help + Say Y here to enable support for I2C connected EETI + EXC3000 multi-touch panels. + + To compile this driver as a module, choose M here: the + module will be called exc3000. + config TOUCHSCREEN_FUJITSU tristate "Fujitsu serial touchscreen" select SERIOdrivers/input/touchscreen/Makefile +1
-0@@ -38,6 +38,7 @@ obj-$(CONFIG_TOUCHSCREEN_ELAN) += elants_i2c.o obj-$(CONFIG_TOUCHSCREEN_ELO) += elo.o obj-$(CONFIG_TOUCHSCREEN_EGALAX) += egalax_ts.o obj-$(CONFIG_TOUCHSCREEN_EGALAX_SERIAL) += egalax_ts_serial.o +obj-$(CONFIG_TOUCHSCREEN_EXC3000) += exc3000.o obj-$(CONFIG_TOUCHSCREEN_FUJITSU) += fujitsu_ts.o obj-$(CONFIG_TOUCHSCREEN_GOODIX) += goodix.o obj-$(CONFIG_TOUCHSCREEN_ILI210X) += ili210x.odrivers/input/touchscreen/exc3000.c new file +11
-0@@ -0,0 +1,154 @@ +/* +* Driver for I2C connected EETI EXC3000 multiple touch controller +* +* Copyright (C) 2017 Ahmet Inan <[email protected]> +* +* minimal implementation based on egalax_ts.c and egalax_i2c.c +* +* This program is free software; you can redistribute it and/or modify +* it under the terms of the GNU General Public License version 2 as +* published by the Free Software Foundation. +*/
drivers/input/touchscreen/exc3000.c line 21
Quoted 10 lines
drivers/input/touchscreen/exc3000.c new file +10
-0+ +#include <linux/module.h> +#include <linux/interrupt.h> +#include <linux/i2c.h> +#include <linux/input.h> +#include <linux/irq.h> +#include <linux/input/mt.h> + +#define NUM_SLOTS 10 +#define PER_FRAME 5
What per frame?
#define EXC3000_NUM_SLOTS 10
#define EXC3000_SLOTS_PER_FRAME 5
drivers/input/touchscreen/exc3000.c line 28
Quoted 7 lines
drivers/input/touchscreen/exc3000.c new file +7
-0+#define LEN_FRAME 66 +#define LEN_POINT 10 + +struct exc3000_data { +struct i2c_client *client; +struct input_dev *input; +unsigned char buf[2 *LEN_FRAME ];
u8 for byte data.
drivers/input/touchscreen/exc3000.c line 39
Quoted 11 lines
drivers/input/touchscreen/exc3000.c new file +11
-0+}; + +static void exc3000_process (struct input_dev *input, +unsigned char *buf,int num) +{ +while (num--) { +int dn, id, x, y; + + dn = buf[0 ] &1 ; + id = buf[1 ]; + x = (buf[3 ] <<8 ) | buf[2 ];
get_unaligned_le16()
drivers/input/touchscreen/exc3000.c line 40
Quoted 1 line
drivers/input/touchscreen/exc3000.c new file +1
-0+ y = (buf[5 ] <<8 ) | buf[4 ];
get_unaligned_le16()
Also, why parse these for released contacts?
Quoted 14 lines
drivers/input/touchscreen/exc3000.c new file +14
-0+ buf +=LEN_POINT ; +if (id >=NUM_SLOTS ) +continue ; +input_mt_slot (input, id); +input_mt_report_slot_state (input,MT_TOOL_FINGER , dn); +if (dn) { +input_report_abs (input,ABS_MT_POSITION_X , x); +input_report_abs (input,ABS_MT_POSITION_Y , y); + } + } +} + +static int exc3000_read (struct i2c_client *client,unsigned char *buf) +{
drivers/input/touchscreen/exc3000.c line 64
Quoted 10 lines
drivers/input/touchscreen/exc3000.c new file +10
-0+if (i2c_master_send (client,"'" ,2 ) !=2 ) +return 1 ; +memset (buf,0 ,LEN_FRAME ); +i2c_master_recv (client, buf,LEN_FRAME ); +return buf[0 ] !=0x42 || buf[1 ] !=0x00 || buf[2 ] !=0x06 ; +} + +static irqreturn_t exc3000_interrupt (int irq,void *dev_id) +{ +struct exc3000_data *data = (struct exc3000_data *)dev_id;
No need to cast.
Quoted 5 lines
drivers/input/touchscreen/exc3000.c new file +5
-0+struct i2c_client *client = data->client; +struct input_dev *input = data->input; +unsigned char *buf = data->buf; + +if (exc3000_read (client, buf) || !buf[3 ] || buf[3 ] >NUM_SLOTS )
drivers/input/touchscreen/exc3000.c line 79
Quoted 10 lines
drivers/input/touchscreen/exc3000.c new file +10
-0+return IRQ_HANDLED ; +if (buf[3 ] <=PER_FRAME ) { +exc3000_process (input, buf +4 , buf[3 ]); + }else { +if (exc3000_read (client, buf +LEN_FRAME ) || buf[LEN_FRAME +3 ]) +return IRQ_HANDLED ; +exc3000_process (input, buf +4 ,PER_FRAME ); +exc3000_process (input, buf +LEN_FRAME +4 , buf[3 ] -PER_FRAME ); + } +input_mt_report_pointer_emulation (input, true);
Not needed with right flags to input_mt_init_slots (INPUT_MT_DIRECT) and call to input_mt_sync_frame() here.
drivers/input/touchscreen/exc3000.c line 91
Quoted 12 lines
drivers/input/touchscreen/exc3000.c new file +12
-0+input_sync (input); +return IRQ_HANDLED ; +} + +static int exc3000_probe (struct i2c_client *client, +const struct i2c_device_id *id) +{ +struct exc3000_data *data; +struct input_dev *input; +int error; + + data = (struct exc3000_data *)devm_kzalloc(&client->dev,
No need to cast.
drivers/input/touchscreen/exc3000.c line 92
Quoted 1 line
drivers/input/touchscreen/exc3000.c new file +1
-0+ sizeof(struct exc3000_data), GFP_KERNEL);
sizeof(*data)
drivers/input/touchscreen/exc3000.c line 103
Quoted 11 lines
drivers/input/touchscreen/exc3000.c new file +11
-0+if (!data) +return -ENOMEM ; + + input =devm_input_allocate_device (&client->dev); +if (!input) +return -ENOMEM ; + + input->name ="EETI EXC3000 Touch Screen" ; + input->id.bustype =BUS_I2C ; + +__set_bit (EV_ABS , input->evbit);
Not needed as input_set_abs_params() does this for you.
drivers/input/touchscreen/exc3000.c line 105
Quoted 2 lines
drivers/input/touchscreen/exc3000.c new file +2
-0+__set_bit (EV_KEY , input->evbit); +__set_bit (BTN_TOUCH , input->keybit);
input_set_capability(input, EV_KEY, BTN_TOUCH);
drivers/input/touchscreen/exc3000.c line 109
Quoted 4 lines
drivers/input/touchscreen/exc3000.c new file +4
-0+input_set_abs_params (input,ABS_X ,0 ,4096 ,0 ,0 ); +input_set_abs_params (input,ABS_Y ,0 ,4096 ,0 ,0 ); +input_set_abs_params (input,ABS_MT_POSITION_X ,0 ,4096 ,0 ,0 ); +input_set_abs_params (input,ABS_MT_POSITION_Y ,0 ,4096 ,0 ,0 );
touchscreen_parse_properties() ?
drivers/input/touchscreen/exc3000.c line 110
Quoted 1 line
drivers/input/touchscreen/exc3000.c new file +1
-0+input_mt_init_slots (input,NUM_SLOTS ,0 );
Needs error handling. INPUT_MT_DIRECT?
drivers/input/touchscreen/exc3000.c line 121
Quoted 11 lines
drivers/input/touchscreen/exc3000.c new file +11
-0+ + error =input_register_device (input); +if (error) +return error; + + data->input = input; + data->client = client; +i2c_set_clientdata (client, data); + + error = devm_request_threaded_irq(&client->dev, client->irq, NULL, + exc3000_interrupt, IRQF_TRIGGER_LOW | IRQF_ONESHOT,
Do not specify trigger explicitly, rely on platform to set it up.
drivers/input/touchscreen/exc3000.c line 133
Quoted 12 lines
drivers/input/touchscreen/exc3000.c new file +12
-0+ client->name, data); +if (error) +return error; + +return 0 ; +} + +static const struct i2c_device_id exc3000_id[] = { + {"exc3000" ,0 }, + { } +}; +
#ifdef CONFIG_OF
drivers/input/touchscreen/exc3000.c line 137
Quoted 4 lines
drivers/input/touchscreen/exc3000.c new file +4
-0+static const struct of_device_id exc3000_dt_ids[] = { + { .compatible ="eeti,exc3000" }, + { } +};
#endif
drivers/input/touchscreen/exc3000.c line 144
Quoted 7 lines
drivers/input/touchscreen/exc3000.c new file +7
-0+ +MODULE_DEVICE_TABLE (i2c, exc3000_id); + +static struct i2c_driver exc3000_driver = { + .driver = { + .name ="exc3000" , + .of_match_table = exc3000_dt_ids,
of_match_ptr()
Quoted 13 lines
drivers/input/touchscreen/exc3000.c new file +10
-0+ }, + .id_table = exc3000_id, + .probe = exc3000_probe, +}; + +module_i2c_driver (exc3000_driver); + +MODULE_AUTHOR ("Ahmet Inan <[email protected]>" ); +MODULE_DESCRIPTION ("I2C connected EETI EXC3000 multiple touch controller driver" ); +MODULE_LICENSE ("GPL" );Signature · 1 line
2.11.0
Thanks.
Signature · 1 line
Dmitry
Dear Dmitry,
Quoted 10 lines
Quoted 3 lines
It is important not to rely on the
i2c_master_recvreturn value:
Ignoring failed transfers sometimes causes hanging touch events, as the controller thinks that the transfer succeeded and won't resend the event.This statement worries me, because you are basically end up reporting garbage. Does the controller sends all active contacts in each frame, or only changed ones? You can use
INPUT_MT_DROP_UNUSEDto let input core automatically drop contacts that were not reported within the last frame. And fire up a timer to release everything if last transfer errors out.
Thank you for the suggestions. I indeed felt uncomfortable about ignoring the return value of i2c_master_recv() but INPUT_MT_DROP_UNUSED helped and now it works awesome!
Quoted 6 lines
drivers/input/touchscreen/exc3000.c line 109
Quoted 4 lines
drivers/input/touchscreen/exc3000.c new file +4
-0+input_set_abs_params (input,ABS_X ,0 ,4096 ,0 ,0 ); +input_set_abs_params (input,ABS_Y ,0 ,4096 ,0 ,0 ); +input_set_abs_params (input,ABS_MT_POSITION_X ,0 ,4096 ,0 ,0 ); +input_set_abs_params (input,ABS_MT_POSITION_Y ,0 ,4096 ,0 ,0 );
touchscreen_parse_properties()?
Need do wrap my head around this. I've send you a new patch with all (but this one) suggested improvements. I will send send you a follow-up patch with touchscreen_parse_properties() if you're OK with the current patch and want to merge it.
Best Regards,
Ahmet
Dear Dmitry,
please hold merging my EXC3000 patch - something just bit me hard and now I get unexplainable hangs since reboot.
Will send you a fixed patch.
Best Regards,
Ahmet
Dear Dmitry,
Quoted 2 lines
please hold merging my EXC3000 patch - something just bit me hard and now I get unexplainable hangs since reboot.
Found out what the hang was: need to specify "active low level-sensitive" in the dt. Fixed it also in the documentation.
I've send you another patch and sorry for the noise ..
Best Regards,
Ahmet
Dear Dmitry,
Quoted 8 lines
Quoted 6 lines
drivers/input/touchscreen/exc3000.c line 109
Quoted 4 lines
drivers/input/touchscreen/exc3000.c new file +4
-0+input_set_abs_params (input,ABS_X ,0 ,4096 ,0 ,0 ); +input_set_abs_params (input,ABS_Y ,0 ,4096 ,0 ,0 ); +input_set_abs_params (input,ABS_MT_POSITION_X ,0 ,4096 ,0 ,0 ); +input_set_abs_params (input,ABS_MT_POSITION_Y ,0 ,4096 ,0 ,0 );
touchscreen_parse_properties()?Need do wrap my head around this.
Thank you for suggesting the use of touchscreen_parse_properties():
Using touchscreen_report_pos() made it very easy to add inversion and swapping support of axes to the driver.
I've also added the new properties from touchscreen.txt to exc3000.txt.
Best Regards,
Ahmet
Dear Dmitry,
Quoted 10 lines
Quoted 10 lines
Quoted 3 lines
It is important not to rely on the
i2c_master_recvreturn value:
Ignoring failed transfers sometimes causes hanging touch events, as the controller thinks that the transfer succeeded and won't resend the event.This statement worries me, because you are basically end up reporting garbage. Does the controller sends all active contacts in each frame, or only changed ones? You can use
INPUT_MT_DROP_UNUSEDto let input core automatically drop contacts that were not reported within the last frame. And fire up a timer to release everything if last transfer errors out.
Quoted 3 lines
Thank you for the suggestions. I indeed felt uncomfortable about ignoring the return value of
i2c_master_recv()butINPUT_MT_DROP_UNUSEDhelped and now it works awesome!
I've just got another EXC3000-Controller-Board to play with and it looks like I need to add that timer you suggested:
I still get sporadically hanging touches with this one :(
So I will send you another patch the moment I figured out how.
Best Regards,
Ahmet