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Migrate IDIO-16 GPIO drivers to regmap API

PATCH Superseded William Breathitt Gray 1 participant 6 messages Mar 31, 2023 – Apr 3, 2023

Subsystems (4)

v4 of 6 Superseded Latest is v6 →

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#0 lore raw

v4 cover Migrate IDIO-16 GPIO drivers to regmap API

Changes in v4:
- Remove superfluous base check in idio_16_reg_mask_xlate()
- Format idio_16_names[] to 8 GPIO per line
- Utilize dev_err_probe() in idio_16_regmap_register()

The regmap API supports IO port accessors so we can take advantage of regmap abstractions rather than handling access to the device registers directly in the driver. The 104-idio-16 and pci-idio-16 modules depend on the IDIO-16 library and are thus updated accordingly.

By leveraging the regmap API, the idio-16 library is reduced to simply a devm_idio_16_regmap_register() function and a configuration structure struct idio_16_regmap_config.

This patchset depends on the "Drop map from handle_mask_sync() parameters" patchset [0].

[0] https://lore.kernel.org/all/[email protected]/

William Breathitt Gray (4):
gpio: idio-16: Migrate to the regmap API
gpio: 104-idio-16: Migrate to the regmap API
gpio: pci-idio-16: Migrate to the regmap API
gpio: idio-16: Remove unused legacy interface

 drivers/gpio/Kconfig            |   7 +-
 drivers/gpio/gpio-104-idio-16.c | 286 +++++++------------------------
 drivers/gpio/gpio-idio-16.c     | 254 ++++++++++++++-------------
 drivers/gpio/gpio-idio-16.h     |  79 +++------
 drivers/gpio/gpio-pci-idio-16.c | 294 +++++++-------------------------
 5 files changed, 289 insertions(+), 631 deletions(-)

base-commit: 4ea0c97776bf8c63805eb0f8182d9c20072219d9
prerequisite-patch-id: cd19046150b7cff1be4ac7152198777aa960a3df
prerequisite-patch-id: bd3e3830d9ce4f3876a77483364d7190b7fdffa7

Signature · 1 line
2.39.2
#1 lore raw

PATCH v4 1/4 gpio: idio-16: Migrate to the regmap API

The regmap API supports IO port accessors so we can take advantage of regmap abstractions rather than handling access to the device registers directly in the driver.

By leveraging the regmap API, the idio-16 library is reduced to simply a devm_idio_16_regmap_register() function and a configuration structure struct idio_16_regmap_config.

Legacy functions and code will be removed once all consumers have migrated to the new idio-16 library interface.

For IDIO-16 devices we have the following IRQ registers:

Base Address +1 (Write): Clear Interrupt
Base Address +2 (Read): Enable Interrupt
Base Address +2 (Write): Disable Interrupt

An interrupt is asserted whenever a change-of-state is detected on any of the inputs. Any write to 0x2 will disable interrupts, while any read will enable interrupts. Interrupts are cleared by a write to 0x1.

For 104-IDIO-16 devices, there is no IRQ status register, so software has to assume that if an interrupt is raised then it was for the 104-IDIO-16 device.

For PCI-IDIO-16 devices, there is an additional IRQ register:

Base Address +6 (Read): Interrupt Status

Interrupt status can be read from 0x6 where bit 2 set indicates that an IRQ has been generated.

---
Changes in v4:
- Remove superfluous base check in idio_16_reg_mask_xlate()
- Format idio_16_names[] to 8 GPIO per line
- Utilize dev_err_probe() in idio_16_regmap_register()

 drivers/gpio/Kconfig        |   3 +
 drivers/gpio/gpio-idio-16.c | 155 ++++++++++++++++++++++++++++++++++++
 drivers/gpio/gpio-idio-16.h |  26 ++++++
 3 files changed, 184 insertions(+)
drivers/gpio/Kconfig +3 -0
index 68f58b0ba79f..415b86cfd1a9 100644
@@ -111,6 +111,9 @@ config GPIO_MAX730X
 
 config GPIO_IDIO_16
 	tristate
+	select REGMAP_IRQ
+	select GPIOLIB_IRQCHIP
+	select GPIO_REGMAP
 	help
 	  Enables support for the idio-16 library functions. The idio-16 library
 	  provides functions to facilitate communication with devices within the
drivers/gpio/gpio-idio-16.c +155 -0

170 lines not on this page · raw message

drivers/gpio/gpio-idio-16.h +26 -0
index 928f8251a2bd..255bd8504ed7 100644
@@ -6,6 +6,30 @@
 #include <linux/spinlock.h>
 #include <linux/types.h>
 
+struct device;
+struct regmap;
+struct regmap_irq;
+
+/**
+ * struct idio_16_regmap_config - Configuration for the IDIO-16 register map
+ * @parent:		parent device
+ * @map:		regmap for the IDIO-16 device
+ * @regmap_irqs:	descriptors for individual IRQs
+ * @num_regmap_irqs:	number of IRQ descriptors
+ * @irq:		IRQ number for the IDIO-16 device
+ * @no_status:		device has no status register
+ * @filters:		device has input filters
+ */
+struct idio_16_regmap_config {
+	struct device *parent;
+	struct regmap *map;
+	const struct regmap_irq *regmap_irqs;
+	int num_regmap_irqs;
+	unsigned int irq;
+	bool no_status;
+	bool filters;
+};
+
 /**
  * struct idio_16 - IDIO-16 registers structure
  * @out0_7:	Read: FET Drive Outputs 0-7
@@ -68,4 +92,6 @@ void idio_16_set_multiple(struct idio_16 __iomem *reg,
 			  const unsigned long *mask, const unsigned long *bits);
 void idio_16_state_init(struct idio_16_state *state);
 
+int devm_idio_16_regmap_register(struct device *dev, const struct idio_16_regmap_config *config);
+
 #endif /* _IDIO_16_H_ */
Signature · 1 line
2.39.2
#2 lore raw

PATCH v4 2/4 gpio: 104-idio-16: Migrate to the regmap API

In reply to William Breathitt Gray

The regmap API supports IO port accessors so we can take advantage of regmap abstractions rather than handling access to the device registers directly in the driver. Migrate the 104-idio-16 module to the new idio-16 library interface leveraging the gpio-regmap API.

---
Changes in v4: none

 drivers/gpio/Kconfig            |   2 +-
 drivers/gpio/gpio-104-idio-16.c | 286 +++++++-------------------------
 2 files changed, 64 insertions(+), 224 deletions(-)
drivers/gpio/Kconfig +1 -1
index 415b86cfd1a9..9f7ec4f3fdbf 100644
@@ -860,7 +860,7 @@ config GPIO_104_IDIO_16
 	tristate "ACCES 104-IDIO-16 GPIO support"
 	depends on PC104
 	select ISA_BUS_API
-	select GPIOLIB_IRQCHIP
+	select REGMAP_MMIO
 	select GPIO_IDIO_16
 	help
 	  Enables GPIO support for the ACCES 104-IDIO-16 family (104-IDIO-16,
drivers/gpio/gpio-104-idio-16.c +63 -223

323 lines not on this page · raw message

Signature · 1 line
2.39.2
#3 lore raw

PATCH v4 3/4 gpio: pci-idio-16: Migrate to the regmap API

In reply to William Breathitt Gray

The regmap API supports IO port accessors so we can take advantage of regmap abstractions rather than handling access to the device registers directly in the driver. Migrate the pci-idio-16 module to the new idio-16 library interface leveraging the gpio-regmap API.

---
Changes in v4: none

 drivers/gpio/Kconfig            |   2 +-
 drivers/gpio/gpio-pci-idio-16.c | 294 +++++++-------------------------
 2 files changed, 62 insertions(+), 234 deletions(-)
drivers/gpio/Kconfig +1 -1
index 9f7ec4f3fdbf..e19b2612e67c 100644
@@ -1580,7 +1580,7 @@ config GPIO_PCH
 
 config GPIO_PCI_IDIO_16
 	tristate "ACCES PCI-IDIO-16 GPIO support"
-	select GPIOLIB_IRQCHIP
+	select REGMAP_MMIO
 	select GPIO_IDIO_16
 	help
 	  Enables GPIO support for the ACCES PCI-IDIO-16. An interrupt is
drivers/gpio/gpio-pci-idio-16.c +61 -233

328 lines not on this page · raw message

Signature · 1 line
2.39.2
#4 lore raw

PATCH v4 4/4 gpio: idio-16: Remove unused legacy interface

In reply to William Breathitt Gray

All idio-16 library consumers have migrated to the new interface leveraging the gpio-regmap API. Legacy interface functions and code are removed as no longer needed.

---
Changes in v4: none

 drivers/gpio/gpio-idio-16.c | 131 +-----------------------------------
 drivers/gpio/gpio-idio-16.h |  65 ------------------
 2 files changed, 1 insertion(+), 195 deletions(-)
drivers/gpio/gpio-idio-16.c +1 -130
index f9349e8d7fdc..53b1eb876a12 100644
@@ -3,15 +3,13 @@
  * GPIO library for the ACCES IDIO-16 family
  * Copyright (C) 2022 William Breathitt Gray
  */
-#include <linux/bitmap.h>
+#include <linux/bits.h>
 #include <linux/device.h>
 #include <linux/err.h>
 #include <linux/export.h>
 #include <linux/gpio/regmap.h>
-#include <linux/io.h>
 #include <linux/module.h>
 #include <linux/regmap.h>
-#include <linux/spinlock.h>
 #include <linux/types.h>
 
 #include "gpio-idio-16.h"
@@ -169,133 +167,6 @@ int devm_idio_16_regmap_register(struct device *const dev,
 }
 EXPORT_SYMBOL_GPL(devm_idio_16_regmap_register);
 
-/**
- * idio_16_get - get signal value at signal offset
- * @reg:	ACCES IDIO-16 device registers
- * @state:	ACCES IDIO-16 device state
- * @offset:	offset of signal to get
- *
- * Returns the signal value (0=low, 1=high) for the signal at @offset.
- */
-int idio_16_get(struct idio_16 __iomem *const reg,
-		struct idio_16_state *const state, const unsigned long offset)
-{
-	const unsigned long mask = BIT(offset);
-
-	if (offset < IDIO_16_NOUT)
-		return test_bit(offset, state->out_state);
-
-	if (offset < 24)
-		return !!(ioread8(&reg->in0_7) & (mask >> IDIO_16_NOUT));
-
-	if (offset < 32)
-		return !!(ioread8(&reg->in8_15) & (mask >> 24));
-
-	return -EINVAL;
-}
-EXPORT_SYMBOL_GPL(idio_16_get);
-
-/**
- * idio_16_get_multiple - get multiple signal values at multiple signal offsets
- * @reg:	ACCES IDIO-16 device registers
- * @state:	ACCES IDIO-16 device state
- * @mask:	mask of signals to get
- * @bits:	bitmap to store signal values
- *
- * Stores in @bits the values (0=low, 1=high) for the signals defined by @mask.
- */
-void idio_16_get_multiple(struct idio_16 __iomem *const reg,
-			  struct idio_16_state *const state,
-			  const unsigned long *const mask,
-			  unsigned long *const bits)
-{
-	unsigned long flags;
-	const unsigned long out_mask = GENMASK(IDIO_16_NOUT - 1, 0);
-
-	spin_lock_irqsave(&state->lock, flags);
-
-	bitmap_replace(bits, bits, state->out_state, &out_mask, IDIO_16_NOUT);
-	if (*mask & GENMASK(23, 16))
-		bitmap_set_value8(bits, ioread8(&reg->in0_7), 16);
-	if (*mask & GENMASK(31, 24))
-		bitmap_set_value8(bits, ioread8(&reg->in8_15), 24);
-
-	spin_unlock_irqrestore(&state->lock, flags);
-}
-EXPORT_SYMBOL_GPL(idio_16_get_multiple);
-
-/**
- * idio_16_set - set signal value at signal offset
- * @reg:	ACCES IDIO-16 device registers
- * @state:	ACCES IDIO-16 device state
- * @offset:	offset of signal to set
- * @value:	value of signal to set
- *
- * Assigns output @value for the signal at @offset.
- */
-void idio_16_set(struct idio_16 __iomem *const reg,
-		 struct idio_16_state *const state, const unsigned long offset,
-		 const unsigned long value)
-{
-	unsigned long flags;
-
-	if (offset >= IDIO_16_NOUT)
-		return;
-
-	spin_lock_irqsave(&state->lock, flags);
-
-	__assign_bit(offset, state->out_state, value);
-	if (offset < 8)
-		iowrite8(bitmap_get_value8(state->out_state, 0), &reg->out0_7);
-	else
-		iowrite8(bitmap_get_value8(state->out_state, 8), &reg->out8_15);
-
-	spin_unlock_irqrestore(&state->lock, flags);
-}
-EXPORT_SYMBOL_GPL(idio_16_set);
-
-/**
- * idio_16_set_multiple - set signal values at multiple signal offsets
- * @reg:	ACCES IDIO-16 device registers
- * @state:	ACCES IDIO-16 device state
- * @mask:	mask of signals to set
- * @bits:	bitmap of signal output values
- *
- * Assigns output values defined by @bits for the signals defined by @mask.
- */
-void idio_16_set_multiple(struct idio_16 __iomem *const reg,
-			  struct idio_16_state *const state,
-			  const unsigned long *const mask,
-			  const unsigned long *const bits)
-{
-	unsigned long flags;
-
-	spin_lock_irqsave(&state->lock, flags);
-
-	bitmap_replace(state->out_state, state->out_state, bits, mask,
-		       IDIO_16_NOUT);
-	if (*mask & GENMASK(7, 0))
-		iowrite8(bitmap_get_value8(state->out_state, 0), &reg->out0_7);
-	if (*mask & GENMASK(15, 8))
-		iowrite8(bitmap_get_value8(state->out_state, 8), &reg->out8_15);
-
-	spin_unlock_irqrestore(&state->lock, flags);
-}
-EXPORT_SYMBOL_GPL(idio_16_set_multiple);
-
-/**
- * idio_16_state_init - initialize idio_16_state structure
- * @state:	ACCES IDIO-16 device state
- *
- * Initializes the ACCES IDIO-16 device @state for use in idio-16 library
- * functions.
- */
-void idio_16_state_init(struct idio_16_state *const state)
-{
-	spin_lock_init(&state->lock);
-}
-EXPORT_SYMBOL_GPL(idio_16_state_init);
-
 MODULE_AUTHOR("William Breathitt Gray");
 MODULE_DESCRIPTION("ACCES IDIO-16 GPIO Library");
 MODULE_LICENSE("GPL");
drivers/gpio/gpio-idio-16.h +0 -65

77 lines not on this page · raw message

Signature · 1 line
2.39.2
#5 lore raw
In reply to William Breathitt Gray
Quoted 33 lines · William Breathitt Gray

Changes in v4:
- Remove superfluous base check in idio_16_reg_mask_xlate()
- Format idio_16_names[] to 8 GPIO per line
- Utilize dev_err_probe() in idio_16_regmap_register()

The regmap API supports IO port accessors so we can take advantage of regmap abstractions rather than handling access to the device registers directly in the driver. The 104-idio-16 and pci-idio-16 modules depend on the IDIO-16 library and are thus updated accordingly.

By leveraging the regmap API, the idio-16 library is reduced to simply a devm_idio_16_regmap_register() function and a configuration structure struct idio_16_regmap_config.

This patchset depends on the "Drop map from handle_mask_sync() parameters" patchset [0].

[0] https://lore.kernel.org/all/[email protected]/

William Breathitt Gray (4):
gpio: idio-16: Migrate to the regmap API
gpio: 104-idio-16: Migrate to the regmap API
gpio: pci-idio-16: Migrate to the regmap API
gpio: idio-16: Remove unused legacy interface

 drivers/gpio/Kconfig            |   7 +-
 drivers/gpio/gpio-104-idio-16.c | 286 +++++++------------------------
 drivers/gpio/gpio-idio-16.c     | 254 ++++++++++++++-------------
 drivers/gpio/gpio-idio-16.h     |  79 +++------
 drivers/gpio/gpio-pci-idio-16.c | 294 +++++++-------------------------
 5 files changed, 289 insertions(+), 631 deletions(-)
Quoted 5 lines

base-commit: 4ea0c97776bf8c63805eb0f8182d9c20072219d9
prerequisite-patch-id: cd19046150b7cff1be4ac7152198777aa960a3df
prerequisite-patch-id: bd3e3830d9ce4f3876a77483364d7190b7fdffa7

Signature · 1 line
2.39.2

The 104-idio-16 and pci-idio-16 drivers here likely need use_raw_spinlock enabled for their respective regmap_config structures to prevent deadlocks as described in the i8255 fixes patchset [0]. I'll submit a v5 of this patchset to fix that.

[0] https://lore.kernel.org/all/[email protected]/