[PATCH v2 0/3] Introduce the ACCES IDIO-16 GPIO library module

[PATCH v2 0/3] Introduce the ACCES IDIO-16 GPIO library module

[William Breathitt Gray]

Changes in v2:
 - Added offset check for last byte of inputs in idio_16_get() for
   robustness
 - Replaced hardcoded '16' with IDIO_16_NOUT constant in idio_16_get*()
 - Renamed IDIO_16 namespace to GPIO_IDIO_16; adjusted 104-idio-16 and
   pci-idio-16 drivers accordingly
 - Utilized DEFAULT_SYMBOL_NAMESPACE to simplify namespace exports
 - Refactored callbacks to utilize cached output states; idio_16_get()
   callback now requires struct idio_16_state state; adjusted
   104-idio-16 and pci-idio-16 drivers accordingly
 - Moved bitmap_fill() to after idio_16_state_init() in idio_16_probe()
   to prevent clobbering out_state if the implementation of
   idio_16_state_init changes in the future
 - Adjusted offset checks in idio_16_set() and idio_16_get_direction()
   to ">= IDIO_16_NOUT" for consistency
 - Utilized __assign_bit() in idio_16_set()
 - Refactored idio_16_*_multiple() callbacks to utilize bitmap_replace()

In a similar vein as the Intel 8255 interface library module [0], the
ACCES IDIO-16 GPIO library module is introduced to consolidate much of
the shared code between the existing 104-IDIO-16 and PCI-IDIO-16 GPIO
drivers.

The idio-16 module exposes consumer library functions to facilitate
communication with devices within the ACCES IDIO-16 family such as the
104-IDIO-16 and the PCI-IDIO-16.

A CONFIG_GPIO_IDIO_16 Kconfig option is introduced by this patch.
Modules wanting access to these idio-16 library functions should select
this Kconfig option and import the GPIO_IDIO_16 symbol namespace.

[0] https://lore.kernel.org/all/d1a24895f2ea67f689c24c34a20ddb43cd7246af.1658324498.git.william.gray@linaro.org/

William Breathitt Gray (3):
  gpio: idio-16: Introduce the ACCES IDIO-16 GPIO library module
  gpio: 104-idio-16: Utilize the idio-16 GPIO library
  gpio: pci-idio-16: Utilize the idio-16 GPIO library

 MAINTAINERS                     |   7 ++
 drivers/gpio/Kconfig            |  11 +++
 drivers/gpio/Makefile           |   1 +
 drivers/gpio/gpio-104-idio-16.c |  88 ++++---------------
 drivers/gpio/gpio-idio-16.c     | 146 ++++++++++++++++++++++++++++++++
 drivers/gpio/gpio-idio-16.h     |  71 ++++++++++++++++
 drivers/gpio/gpio-pci-idio-16.c | 119 +++-----------------------
 7 files changed, 265 insertions(+), 178 deletions(-)
 create mode 100644 drivers/gpio/gpio-idio-16.c
 create mode 100644 drivers/gpio/gpio-idio-16.h


base-commit: d9e7f0e320516c660d6f33e6c16a3d99970eb14e
-- 
2.37.3

[PATCH v2 1/3] gpio: idio-16: Introduce the ACCES IDIO-16 GPIO library module

[William Breathitt Gray]

Exposes consumer library functions to facilitate communication with
devices within the ACCES IDIO-16 family such as the 104-IDIO-16 and
the PCI-IDIO-16.

A CONFIG_GPIO_IDIO_16 Kconfig option is introduced by this patch.
Modules wanting access to these idio-16 library functions should select
this Kconfig option and import the GPIO_IDIO_16 symbol namespace.

Cc: Andy Shevchenko <andriy.shevchenko@intel.com>
Signed-off-by: William Breathitt Gray <william.gray@linaro.org>
---
 MAINTAINERS                 |   7 ++
 drivers/gpio/Kconfig        |   9 +++
 drivers/gpio/Makefile       |   1 +
 drivers/gpio/gpio-idio-16.c | 146 ++++++++++++++++++++++++++++++++++++
 drivers/gpio/gpio-idio-16.h |  71 ++++++++++++++++++
 5 files changed, 234 insertions(+)
 create mode 100644 drivers/gpio/gpio-idio-16.c
 create mode 100644 drivers/gpio/gpio-idio-16.h

diff --git a/MAINTAINERS b/MAINTAINERS
index 8a5012ba6ff9..93938b0bdb91 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -312,6 +312,13 @@ L:	linux-iio@vger.kernel.org
 S:	Maintained
 F:	drivers/counter/104-quad-8.c
 
+ACCES IDIO-16 GPIO LIBRARY
+M:	William Breathitt Gray <william.gray@linaro.org>
+L:	linux-gpio@vger.kernel.org
+S:	Maintained
+F:	drivers/gpio/gpio-idio-16.c
+F:	drivers/gpio/gpio-idio-16.h
+
 ACCES PCI-IDIO-16 GPIO DRIVER
 M:	William Breathitt Gray <william.gray@linaro.org>
 L:	linux-gpio@vger.kernel.org
diff --git a/drivers/gpio/Kconfig b/drivers/gpio/Kconfig
index ed9e71d6713e..551351e11365 100644
--- a/drivers/gpio/Kconfig
+++ b/drivers/gpio/Kconfig
@@ -109,6 +109,15 @@ config GPIO_REGMAP
 config GPIO_MAX730X
 	tristate
 
+config GPIO_IDIO_16
+	tristate
+	help
+	  Enables support for the idio-16 library functions. The idio-16 library
+	  provides functions to facilitate communication with devices within the
+	  ACCES IDIO-16 family such as the 104-IDIO-16 and the PCI-IDIO-16.
+
+	  If built as a module its name will be gpio-idio-16.
+
 menu "Memory mapped GPIO drivers"
 	depends on HAS_IOMEM
 
diff --git a/drivers/gpio/Makefile b/drivers/gpio/Makefile
index b67e29d348cf..15abf88c167b 100644
--- a/drivers/gpio/Makefile
+++ b/drivers/gpio/Makefile
@@ -69,6 +69,7 @@ obj-$(CONFIG_GPIO_HLWD)			+= gpio-hlwd.o
 obj-$(CONFIG_HTC_EGPIO)			+= gpio-htc-egpio.o
 obj-$(CONFIG_GPIO_I8255)		+= gpio-i8255.o
 obj-$(CONFIG_GPIO_ICH)			+= gpio-ich.o
+obj-$(CONFIG_GPIO_IDIO_16)		+= gpio-idio-16.o
 obj-$(CONFIG_GPIO_IDT3243X)		+= gpio-idt3243x.o
 obj-$(CONFIG_GPIO_IMX_SCU)		+= gpio-imx-scu.o
 obj-$(CONFIG_GPIO_IOP)			+= gpio-iop.o
diff --git a/drivers/gpio/gpio-idio-16.c b/drivers/gpio/gpio-idio-16.c
new file mode 100644
index 000000000000..13315242d220
--- /dev/null
+++ b/drivers/gpio/gpio-idio-16.c
@@ -0,0 +1,146 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * GPIO library for the ACCES IDIO-16 family
+ * Copyright (C) 2022 William Breathitt Gray
+ */
+#include <linux/bitmap.h>
+#include <linux/export.h>
+#include <linux/io.h>
+#include <linux/module.h>
+#include <linux/spinlock.h>
+#include <linux/types.h>
+
+#include "gpio-idio-16.h"
+
+#define DEFAULT_SYMBOL_NAMESPACE GPIO_IDIO_16
+
+/**
+ * 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");
diff --git a/drivers/gpio/gpio-idio-16.h b/drivers/gpio/gpio-idio-16.h
new file mode 100644
index 000000000000..928f8251a2bd
--- /dev/null
+++ b/drivers/gpio/gpio-idio-16.h
@@ -0,0 +1,71 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/* Copyright 2022 William Breathitt Gray */
+#ifndef _IDIO_16_H_
+#define _IDIO_16_H_
+
+#include <linux/spinlock.h>
+#include <linux/types.h>
+
+/**
+ * struct idio_16 - IDIO-16 registers structure
+ * @out0_7:	Read: FET Drive Outputs 0-7
+ *		Write: FET Drive Outputs 0-7
+ * @in0_7:	Read: Isolated Inputs 0-7
+ *		Write: Clear Interrupt
+ * @irq_ctl:	Read: Enable IRQ
+ *		Write: Disable IRQ
+ * @filter_ctl:	Read: Activate Input Filters 0-15
+ *		Write: Deactivate Input Filters 0-15
+ * @out8_15:	Read: FET Drive Outputs 8-15
+ *		Write: FET Drive Outputs 8-15
+ * @in8_15:	Read: Isolated Inputs 8-15
+ *		Write: Unused
+ * @irq_status:	Read: Interrupt status
+ *		Write: Unused
+ */
+struct idio_16 {
+	u8 out0_7;
+	u8 in0_7;
+	u8 irq_ctl;
+	u8 filter_ctl;
+	u8 out8_15;
+	u8 in8_15;
+	u8 irq_status;
+};
+
+#define IDIO_16_NOUT 16
+
+/**
+ * struct idio_16_state - IDIO-16 state structure
+ * @lock:	synchronization lock for accessing device state
+ * @out_state:	output signals state
+ */
+struct idio_16_state {
+	spinlock_t lock;
+	DECLARE_BITMAP(out_state, IDIO_16_NOUT);
+};
+
+/**
+ * idio_16_get_direction - get the I/O direction for a signal offset
+ * @offset:	offset of signal to get direction
+ *
+ * Returns the signal direction (0=output, 1=input) for the signal at @offset.
+ */
+static inline int idio_16_get_direction(const unsigned long offset)
+{
+	return (offset >= IDIO_16_NOUT) ? 1 : 0;
+}
+
+int idio_16_get(struct idio_16 __iomem *reg, struct idio_16_state *state,
+		unsigned long offset);
+void idio_16_get_multiple(struct idio_16 __iomem *reg,
+			  struct idio_16_state *state,
+			  const unsigned long *mask, unsigned long *bits);
+void idio_16_set(struct idio_16 __iomem *reg, struct idio_16_state *state,
+		 unsigned long offset, unsigned long value);
+void idio_16_set_multiple(struct idio_16 __iomem *reg,
+			  struct idio_16_state *state,
+			  const unsigned long *mask, const unsigned long *bits);
+void idio_16_state_init(struct idio_16_state *state);
+
+#endif /* _IDIO_16_H_ */
-- 
2.37.3

[PATCH v2 2/3] gpio: 104-idio-16: Utilize the idio-16 GPIO library

[William Breathitt Gray]

The ACCES 104-IDIO-16 device is part of the ACCES IDIO-16 family, so the
idio-16 GPIO library module is selected and utilized to consolidate
code.

Signed-off-by: William Breathitt Gray <william.gray@linaro.org>
---
 drivers/gpio/Kconfig            |  1 +
 drivers/gpio/gpio-104-idio-16.c | 88 ++++++---------------------------
 2 files changed, 17 insertions(+), 72 deletions(-)

diff --git a/drivers/gpio/Kconfig b/drivers/gpio/Kconfig
index 551351e11365..48846ee476e2 100644
--- a/drivers/gpio/Kconfig
+++ b/drivers/gpio/Kconfig
@@ -866,6 +866,7 @@ config GPIO_104_IDIO_16
 	depends on PC104
 	select ISA_BUS_API
 	select GPIOLIB_IRQCHIP
+	select GPIO_IDIO_16
 	help
 	  Enables GPIO support for the ACCES 104-IDIO-16 family (104-IDIO-16,
 	  104-IDIO-16E, 104-IDO-16, 104-IDIO-8, 104-IDIO-8E, 104-IDO-8). The
diff --git a/drivers/gpio/gpio-104-idio-16.c b/drivers/gpio/gpio-104-idio-16.c
index 73d95b55a8c5..0f4d36c09aa4 100644
--- a/drivers/gpio/gpio-104-idio-16.c
+++ b/drivers/gpio/gpio-104-idio-16.c
@@ -6,7 +6,7 @@
  * This driver supports the following ACCES devices: 104-IDIO-16,
  * 104-IDIO-16E, 104-IDO-16, 104-IDIO-8, 104-IDIO-8E, and 104-IDO-8.
  */
-#include <linux/bits.h>
+#include <linux/bitmap.h>
 #include <linux/device.h>
 #include <linux/errno.h>
 #include <linux/gpio/driver.h>
@@ -21,6 +21,8 @@
 #include <linux/spinlock.h>
 #include <linux/types.h>
 
+#include "gpio-idio-16.h"
+
 #define IDIO_16_EXTENT 8
 #define MAX_NUM_IDIO_16 max_num_isa_dev(IDIO_16_EXTENT)
 
@@ -34,49 +36,26 @@ static unsigned int num_irq;
 module_param_hw_array(irq, uint, irq, &num_irq, 0);
 MODULE_PARM_DESC(irq, "ACCES 104-IDIO-16 interrupt line numbers");
 
-/**
- * struct idio_16_reg - device registers structure
- * @out0_7:	Read: N/A
- *		Write: FET Drive Outputs 0-7
- * @in0_7:	Read: Isolated Inputs 0-7
- *		Write: Clear Interrupt
- * @irq_ctl:	Read: Enable IRQ
- *		Write: Disable IRQ
- * @unused:	N/A
- * @out8_15:	Read: N/A
- *		Write: FET Drive Outputs 8-15
- * @in8_15:	Read: Isolated Inputs 8-15
- *		Write: N/A
- */
-struct idio_16_reg {
-	u8 out0_7;
-	u8 in0_7;
-	u8 irq_ctl;
-	u8 unused;
-	u8 out8_15;
-	u8 in8_15;
-};
-
 /**
  * struct idio_16_gpio - GPIO device private data structure
  * @chip:	instance of the gpio_chip
  * @lock:	synchronization lock to prevent I/O race conditions
  * @irq_mask:	I/O bits affected by interrupts
  * @reg:	I/O address offset for the device registers
- * @out_state:	output bits state
+ * @state:	ACCES IDIO-16 device state
  */
 struct idio_16_gpio {
 	struct gpio_chip chip;
 	raw_spinlock_t lock;
 	unsigned long irq_mask;
-	struct idio_16_reg __iomem *reg;
-	unsigned int out_state;
+	struct idio_16 __iomem *reg;
+	struct idio_16_state state;
 };
 
 static int idio_16_gpio_get_direction(struct gpio_chip *chip,
 				      unsigned int offset)
 {
-	if (offset > 15)
+	if (idio_16_get_direction(offset))
 		return GPIO_LINE_DIRECTION_IN;
 
 	return GPIO_LINE_DIRECTION_OUT;
@@ -98,15 +77,8 @@ static int idio_16_gpio_direction_output(struct gpio_chip *chip,
 static int idio_16_gpio_get(struct gpio_chip *chip, unsigned int offset)
 {
 	struct idio_16_gpio *const idio16gpio = gpiochip_get_data(chip);
-	const unsigned int mask = BIT(offset-16);
 
-	if (offset < 16)
-		return -EINVAL;
-
-	if (offset < 24)
-		return !!(ioread8(&idio16gpio->reg->in0_7) & mask);
-
-	return !!(ioread8(&idio16gpio->reg->in8_15) & (mask>>8));
+	return idio_16_get(idio16gpio->reg, &idio16gpio->state, offset);
 }
 
 static int idio_16_gpio_get_multiple(struct gpio_chip *chip,
@@ -114,11 +86,7 @@ static int idio_16_gpio_get_multiple(struct gpio_chip *chip,
 {
 	struct idio_16_gpio *const idio16gpio = gpiochip_get_data(chip);
 
-	*bits = 0;
-	if (*mask & GENMASK(23, 16))
-		*bits |= (unsigned long)ioread8(&idio16gpio->reg->in0_7) << 16;
-	if (*mask & GENMASK(31, 24))
-		*bits |= (unsigned long)ioread8(&idio16gpio->reg->in8_15) << 24;
+	idio_16_get_multiple(idio16gpio->reg, &idio16gpio->state, mask, bits);
 
 	return 0;
 }
@@ -127,44 +95,16 @@ static void idio_16_gpio_set(struct gpio_chip *chip, unsigned int offset,
 			     int value)
 {
 	struct idio_16_gpio *const idio16gpio = gpiochip_get_data(chip);
-	const unsigned int mask = BIT(offset);
-	unsigned long flags;
 
-	if (offset > 15)
-		return;
-
-	raw_spin_lock_irqsave(&idio16gpio->lock, flags);
-
-	if (value)
-		idio16gpio->out_state |= mask;
-	else
-		idio16gpio->out_state &= ~mask;
-
-	if (offset > 7)
-		iowrite8(idio16gpio->out_state >> 8, &idio16gpio->reg->out8_15);
-	else
-		iowrite8(idio16gpio->out_state, &idio16gpio->reg->out0_7);
-
-	raw_spin_unlock_irqrestore(&idio16gpio->lock, flags);
+	idio_16_set(idio16gpio->reg, &idio16gpio->state, offset, value);
 }
 
 static void idio_16_gpio_set_multiple(struct gpio_chip *chip,
 	unsigned long *mask, unsigned long *bits)
 {
 	struct idio_16_gpio *const idio16gpio = gpiochip_get_data(chip);
-	unsigned long flags;
 
-	raw_spin_lock_irqsave(&idio16gpio->lock, flags);
-
-	idio16gpio->out_state &= ~*mask;
-	idio16gpio->out_state |= *mask & *bits;
-
-	if (*mask & 0xFF)
-		iowrite8(idio16gpio->out_state, &idio16gpio->reg->out0_7);
-	if ((*mask >> 8) & 0xFF)
-		iowrite8(idio16gpio->out_state >> 8, &idio16gpio->reg->out8_15);
-
-	raw_spin_unlock_irqrestore(&idio16gpio->lock, flags);
+	idio_16_set_multiple(idio16gpio->reg, &idio16gpio->state, mask, bits);
 }
 
 static void idio_16_irq_ack(struct irq_data *data)
@@ -297,7 +237,10 @@ static int idio_16_probe(struct device *dev, unsigned int id)
 	idio16gpio->chip.get_multiple = idio_16_gpio_get_multiple;
 	idio16gpio->chip.set = idio_16_gpio_set;
 	idio16gpio->chip.set_multiple = idio_16_gpio_set_multiple;
-	idio16gpio->out_state = 0xFFFF;
+
+	idio_16_state_init(&idio16gpio->state);
+	/* FET off states are represented by bit values of "1" */
+	bitmap_fill(idio16gpio->state.out_state, IDIO_16_NOUT);
 
 	girq = &idio16gpio->chip.irq;
 	girq->chip = &idio_16_irqchip;
@@ -339,3 +282,4 @@ module_isa_driver_with_irq(idio_16_driver, num_idio_16, num_irq);
 MODULE_AUTHOR("William Breathitt Gray <vilhelm.gray@gmail.com>");
 MODULE_DESCRIPTION("ACCES 104-IDIO-16 GPIO driver");
 MODULE_LICENSE("GPL v2");
+MODULE_IMPORT_NS(GPIO_IDIO_16);
-- 
2.37.3

[PATCH v2 3/3] gpio: pci-idio-16: Utilize the idio-16 GPIO library

[William Breathitt Gray]

The ACCES PCI-IDIO-16 device is part of the ACCES IDIO-16 family, so the
idio-16 GPIO library module is selected and utilized to consolidate
code.

Signed-off-by: William Breathitt Gray <william.gray@linaro.org>
---
 drivers/gpio/Kconfig            |   1 +
 drivers/gpio/gpio-pci-idio-16.c | 119 ++++----------------------------
 2 files changed, 14 insertions(+), 106 deletions(-)

diff --git a/drivers/gpio/Kconfig b/drivers/gpio/Kconfig
index 48846ee476e2..8b90bff7b198 100644
--- a/drivers/gpio/Kconfig
+++ b/drivers/gpio/Kconfig
@@ -1585,6 +1585,7 @@ config GPIO_PCH
 config GPIO_PCI_IDIO_16
 	tristate "ACCES PCI-IDIO-16 GPIO support"
 	select GPIOLIB_IRQCHIP
+	select GPIO_IDIO_16
 	help
 	  Enables GPIO support for the ACCES PCI-IDIO-16. An interrupt is
 	  generated when any of the inputs change state (low to high or high to
diff --git a/drivers/gpio/gpio-pci-idio-16.c b/drivers/gpio/gpio-pci-idio-16.c
index 71a13a394050..a86ce748384b 100644
--- a/drivers/gpio/gpio-pci-idio-16.c
+++ b/drivers/gpio/gpio-pci-idio-16.c
@@ -3,8 +3,7 @@
  * GPIO driver for the ACCES PCI-IDIO-16
  * Copyright (C) 2017 William Breathitt Gray
  */
-#include <linux/bitmap.h>
-#include <linux/bitops.h>
+#include <linux/bits.h>
 #include <linux/device.h>
 #include <linux/errno.h>
 #include <linux/gpio/driver.h>
@@ -16,51 +15,28 @@
 #include <linux/spinlock.h>
 #include <linux/types.h>
 
-/**
- * struct idio_16_gpio_reg - GPIO device registers structure
- * @out0_7:	Read: FET Drive Outputs 0-7
- *		Write: FET Drive Outputs 0-7
- * @in0_7:	Read: Isolated Inputs 0-7
- *		Write: Clear Interrupt
- * @irq_ctl:	Read: Enable IRQ
- *		Write: Disable IRQ
- * @filter_ctl:	Read: Activate Input Filters 0-15
- *		Write: Deactivate Input Filters 0-15
- * @out8_15:	Read: FET Drive Outputs 8-15
- *		Write: FET Drive Outputs 8-15
- * @in8_15:	Read: Isolated Inputs 8-15
- *		Write: Unused
- * @irq_status:	Read: Interrupt status
- *		Write: Unused
- */
-struct idio_16_gpio_reg {
-	u8 out0_7;
-	u8 in0_7;
-	u8 irq_ctl;
-	u8 filter_ctl;
-	u8 out8_15;
-	u8 in8_15;
-	u8 irq_status;
-};
+#include "gpio-idio-16.h"
 
 /**
  * struct idio_16_gpio - GPIO device private data structure
  * @chip:	instance of the gpio_chip
  * @lock:	synchronization lock to prevent I/O race conditions
  * @reg:	I/O address offset for the GPIO device registers
+ * @state:	ACCES IDIO-16 device state
  * @irq_mask:	I/O bits affected by interrupts
  */
 struct idio_16_gpio {
 	struct gpio_chip chip;
 	raw_spinlock_t lock;
-	struct idio_16_gpio_reg __iomem *reg;
+	struct idio_16 __iomem *reg;
+	struct idio_16_state state;
 	unsigned long irq_mask;
 };
 
 static int idio_16_gpio_get_direction(struct gpio_chip *chip,
 	unsigned int offset)
 {
-	if (offset > 15)
+	if (idio_16_get_direction(offset))
 		return GPIO_LINE_DIRECTION_IN;
 
 	return GPIO_LINE_DIRECTION_OUT;
@@ -82,43 +58,16 @@ static int idio_16_gpio_direction_output(struct gpio_chip *chip,
 static int idio_16_gpio_get(struct gpio_chip *chip, unsigned int offset)
 {
 	struct idio_16_gpio *const idio16gpio = gpiochip_get_data(chip);
-	unsigned long mask = BIT(offset);
-
-	if (offset < 8)
-		return !!(ioread8(&idio16gpio->reg->out0_7) & mask);
-
-	if (offset < 16)
-		return !!(ioread8(&idio16gpio->reg->out8_15) & (mask >> 8));
-
-	if (offset < 24)
-		return !!(ioread8(&idio16gpio->reg->in0_7) & (mask >> 16));
 
-	return !!(ioread8(&idio16gpio->reg->in8_15) & (mask >> 24));
+	return idio_16_get(idio16gpio->reg, &idio16gpio->state, offset);
 }
 
 static int idio_16_gpio_get_multiple(struct gpio_chip *chip,
 	unsigned long *mask, unsigned long *bits)
 {
 	struct idio_16_gpio *const idio16gpio = gpiochip_get_data(chip);
-	unsigned long offset;
-	unsigned long gpio_mask;
-	void __iomem *ports[] = {
-		&idio16gpio->reg->out0_7, &idio16gpio->reg->out8_15,
-		&idio16gpio->reg->in0_7, &idio16gpio->reg->in8_15,
-	};
-	void __iomem *port_addr;
-	unsigned long port_state;
-
-	/* clear bits array to a clean slate */
-	bitmap_zero(bits, chip->ngpio);
-
-	for_each_set_clump8(offset, gpio_mask, mask, ARRAY_SIZE(ports) * 8) {
-		port_addr = ports[offset / 8];
-		port_state = ioread8(port_addr) & gpio_mask;
-
-		bitmap_set_value8(bits, port_state, offset);
-	}
 
+	idio_16_get_multiple(idio16gpio->reg, &idio16gpio->state, mask, bits);
 	return 0;
 }
 
@@ -126,61 +75,16 @@ static void idio_16_gpio_set(struct gpio_chip *chip, unsigned int offset,
 	int value)
 {
 	struct idio_16_gpio *const idio16gpio = gpiochip_get_data(chip);
-	unsigned int mask = BIT(offset);
-	void __iomem *base;
-	unsigned long flags;
-	unsigned int out_state;
-
-	if (offset > 15)
-		return;
-
-	if (offset > 7) {
-		mask >>= 8;
-		base = &idio16gpio->reg->out8_15;
-	} else
-		base = &idio16gpio->reg->out0_7;
-
-	raw_spin_lock_irqsave(&idio16gpio->lock, flags);
 
-	if (value)
-		out_state = ioread8(base) | mask;
-	else
-		out_state = ioread8(base) & ~mask;
-
-	iowrite8(out_state, base);
-
-	raw_spin_unlock_irqrestore(&idio16gpio->lock, flags);
+	idio_16_set(idio16gpio->reg, &idio16gpio->state, offset, value);
 }
 
 static void idio_16_gpio_set_multiple(struct gpio_chip *chip,
 	unsigned long *mask, unsigned long *bits)
 {
 	struct idio_16_gpio *const idio16gpio = gpiochip_get_data(chip);
-	unsigned long offset;
-	unsigned long gpio_mask;
-	void __iomem *ports[] = {
-		&idio16gpio->reg->out0_7, &idio16gpio->reg->out8_15,
-	};
-	size_t index;
-	void __iomem *port_addr;
-	unsigned long bitmask;
-	unsigned long flags;
-	unsigned long out_state;
 
-	for_each_set_clump8(offset, gpio_mask, mask, ARRAY_SIZE(ports) * 8) {
-		index = offset / 8;
-		port_addr = ports[index];
-
-		bitmask = bitmap_get_value8(bits, offset) & gpio_mask;
-
-		raw_spin_lock_irqsave(&idio16gpio->lock, flags);
-
-		out_state = ioread8(port_addr) & ~gpio_mask;
-		out_state |= bitmask;
-		iowrite8(out_state, port_addr);
-
-		raw_spin_unlock_irqrestore(&idio16gpio->lock, flags);
-	}
+	idio_16_set_multiple(idio16gpio->reg, &idio16gpio->state, mask, bits);
 }
 
 static void idio_16_irq_ack(struct irq_data *data)
@@ -335,6 +239,8 @@ static int idio_16_probe(struct pci_dev *pdev, const struct pci_device_id *id)
 	idio16gpio->chip.set = idio_16_gpio_set;
 	idio16gpio->chip.set_multiple = idio_16_gpio_set_multiple;
 
+	idio_16_state_init(&idio16gpio->state);
+
 	girq = &idio16gpio->chip.irq;
 	girq->chip = &idio_16_irqchip;
 	/* This will let us handle the parent IRQ in the driver */
@@ -379,3 +285,4 @@ module_pci_driver(idio_16_driver);
 MODULE_AUTHOR("William Breathitt Gray <vilhelm.gray@gmail.com>");
 MODULE_DESCRIPTION("ACCES PCI-IDIO-16 GPIO driver");
 MODULE_LICENSE("GPL v2");
+MODULE_IMPORT_NS(GPIO_IDIO_16);
-- 
2.37.3

Re: [PATCH v2 0/3] Introduce the ACCES IDIO-16 GPIO library module

[Bartosz Golaszewski]

On Sun, Sep 18, 2022 at 9:54 PM William Breathitt Gray
<william.gray@linaro.org> wrote:
>
> Changes in v2:
>  - Added offset check for last byte of inputs in idio_16_get() for
>    robustness
>  - Replaced hardcoded '16' with IDIO_16_NOUT constant in idio_16_get*()
>  - Renamed IDIO_16 namespace to GPIO_IDIO_16; adjusted 104-idio-16 and
>    pci-idio-16 drivers accordingly
>  - Utilized DEFAULT_SYMBOL_NAMESPACE to simplify namespace exports
>  - Refactored callbacks to utilize cached output states; idio_16_get()
>    callback now requires struct idio_16_state state; adjusted
>    104-idio-16 and pci-idio-16 drivers accordingly
>  - Moved bitmap_fill() to after idio_16_state_init() in idio_16_probe()
>    to prevent clobbering out_state if the implementation of
>    idio_16_state_init changes in the future
>  - Adjusted offset checks in idio_16_set() and idio_16_get_direction()
>    to ">= IDIO_16_NOUT" for consistency
>  - Utilized __assign_bit() in idio_16_set()
>  - Refactored idio_16_*_multiple() callbacks to utilize bitmap_replace()
>
> In a similar vein as the Intel 8255 interface library module [0], the
> ACCES IDIO-16 GPIO library module is introduced to consolidate much of
> the shared code between the existing 104-IDIO-16 and PCI-IDIO-16 GPIO
> drivers.
>
> The idio-16 module exposes consumer library functions to facilitate
> communication with devices within the ACCES IDIO-16 family such as the
> 104-IDIO-16 and the PCI-IDIO-16.
>
> A CONFIG_GPIO_IDIO_16 Kconfig option is introduced by this patch.
> Modules wanting access to these idio-16 library functions should select
> this Kconfig option and import the GPIO_IDIO_16 symbol namespace.
>
> [0] https://lore.kernel.org/all/d1a24895f2ea67f689c24c34a20ddb43cd7246af.1658324498.git.william.gray@linaro.org/
>
> William Breathitt Gray (3):
>   gpio: idio-16: Introduce the ACCES IDIO-16 GPIO library module
>   gpio: 104-idio-16: Utilize the idio-16 GPIO library
>   gpio: pci-idio-16: Utilize the idio-16 GPIO library
>
>  MAINTAINERS                     |   7 ++
>  drivers/gpio/Kconfig            |  11 +++
>  drivers/gpio/Makefile           |   1 +
>  drivers/gpio/gpio-104-idio-16.c |  88 ++++---------------
>  drivers/gpio/gpio-idio-16.c     | 146 ++++++++++++++++++++++++++++++++
>  drivers/gpio/gpio-idio-16.h     |  71 ++++++++++++++++
>  drivers/gpio/gpio-pci-idio-16.c | 119 +++-----------------------
>  7 files changed, 265 insertions(+), 178 deletions(-)
>  create mode 100644 drivers/gpio/gpio-idio-16.c
>  create mode 100644 drivers/gpio/gpio-idio-16.h
>
>
> base-commit: d9e7f0e320516c660d6f33e6c16a3d99970eb14e
> --
> 2.37.3
>

This series looks good to me, Andy do you have any objections?
Otherwise, I'll queue it soon.

Bartosz

Re: [PATCH v2 0/3] Introduce the ACCES IDIO-16 GPIO library module

[Andy Shevchenko]

On Thu, Oct 20, 2022 at 02:10:58PM +0200, Bartosz Golaszewski wrote:
> On Sun, Sep 18, 2022 at 9:54 PM William Breathitt Gray
> <william.gray@linaro.org> wrote:

> This series looks good to me, Andy do you have any objections?
> Otherwise, I'll queue it soon.

Nope. If anything, we can fix iteratively later on.
Thanks!

-- 
With Best Regards,
Andy Shevchenko

Re: [PATCH v2 1/3] gpio: idio-16: Introduce the ACCES IDIO-16 GPIO library module

[Bartosz Golaszewski]

On Sun, Sep 18, 2022 at 9:54 PM William Breathitt Gray
<william.gray@linaro.org> wrote:
>
> Exposes consumer library functions to facilitate communication with
> devices within the ACCES IDIO-16 family such as the 104-IDIO-16 and
> the PCI-IDIO-16.
>
> A CONFIG_GPIO_IDIO_16 Kconfig option is introduced by this patch.
> Modules wanting access to these idio-16 library functions should select
> this Kconfig option and import the GPIO_IDIO_16 symbol namespace.
>
> Cc: Andy Shevchenko <andriy.shevchenko@intel.com>
> Signed-off-by: William Breathitt Gray <william.gray@linaro.org>
> ---

Queued, thanks!

Bart