[PATCH v4 0/9] Migrate i8255 GPIO drivers to regmap API

[PATCH v4 0/9] Migrate i8255 GPIO drivers to regmap API

[William Breathitt Gray]

Changes in v4:
 - Align trailing '\' characters in macros to same column in 104-dio-48e
   and 104-idi-48
 - Remove superfluous trailing commas in macros in 104-dio-48e and
   104-idi-48
 - Simplify dio48e_handle_mask_sync() regmap_* calls error checks to
   return error codes directly
 - Refactor dio48e_irq_init_hw() for regmap and comment about spurious
   interrupts; in theory this should be enough to prevent spurious
   interrupts before the system is ready, but we can pass this function
   as a callback where needed in the future
 - Cleanup '{0}' as '{}' in probe() callbacks for 104-dio-48e,
   104-idi-48, and gpio-mm
 - Utilize dev_err_probe() in probe() callbacks for 104-dio-48e and
   104-idi-48
 - Provide convenience comments for idi48_regmap_irqs initialization
   list
 - Replace header includes with forward declarations in gpio-i8255.h

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-dio-48e and gpio-mm modules depend on
the i8255 library and are thus updated accordingly.

The 104-IDI-48 is hardwired as an input-only device. Because the i8255
control registers are not exposed on the 104-IDI-48, the i8255 library
doesn't provide much benefit here. In this case it's simpler to utilize
the gpio_regmap API directly, so this patch series does such and removes
the i8255 library dependency from the 104-idi-48 module.

The first patch in this series adjusts gpio_regmap to always set
gpio_chip get_direction. This patch is mostly independent of the rest of
the patches in the series and can be picked up separately if desired.
I'm including it here because it allows the input-only 104-idi-48 driver
to continue reporting offset directions after migrating to gpio_regmap.

A handle_mask_sync() callback is introduced for the regmap_irq API. This
is used by the 104-dio-48e driver to handle its enable/disable interrupt
functionality. The 104-DIO-48E has a single register to handle
enabling/disabling interrupts: a write of any value to this register
enables interrupts, while any read disables interrupts.

By leveraging the gpio_regmap API, the i8255 library is reduced to
simply a devm_i8255_regmap_register() function, a configuration
structure struct i8255_regmap_config, and a helper macro
i8255_volatile_regmap_range() provided to simplify volatile PPI register
hinting for the regmap.

The regmap_irq API is leveraged by the 104-idi-48 and 104-dio-48e
modules to support their IRQ functionality. Do their respective regmap
configurations need use_hwlock set to true in this case, or is adequate
locking already handled by the regmap_irq API?

William Breathitt Gray (9):
  gpio: regmap: Always set gpio_chip get_direction
  regmap-irq: Add handle_mask_sync() callback
  gpio: 104-dio-48e: Migrate to the regmap-irq API
  gpio: 104-idi-48: Migrate to the regmap-irq API
  gpio: 104-idi-48: Migrate to gpio-regmap API
  gpio: i8255: Migrate to gpio-regmap API
  gpio: 104-dio-48e: Migrate to regmap API
  gpio: gpio-mm: Migrate to regmap API
  gpio: i8255: Remove unused legacy interface

 drivers/base/regmap/regmap-irq.c |  44 +++-
 drivers/gpio/Kconfig             |   5 +-
 drivers/gpio/gpio-104-dio-48e.c  | 391 ++++++++++---------------------
 drivers/gpio/gpio-104-idi-48.c   | 336 +++++++++-----------------
 drivers/gpio/gpio-gpio-mm.c      | 154 +++---------
 drivers/gpio/gpio-i8255.c        | 320 +++++++------------------
 drivers/gpio/gpio-i8255.h        |  54 ++---
 drivers/gpio/gpio-regmap.c       |   7 +-
 include/linux/regmap.h           |   5 +
 9 files changed, 416 insertions(+), 900 deletions(-)


base-commit: 3b7c7478eda00945987d45f902bc3942c89243d3
-- 
2.38.1

[PATCH v4 1/9] gpio: regmap: Always set gpio_chip get_direction

[William Breathitt Gray]

If you only have reg_dat_base set, then it is input-only; if you only
have reg_set_base set, then it is output-only. Thus, we can always set
gpio_chip get_direction to gpio_regmap_get_direction and return
GPIO_LINE_DIRECTION_IN/GPIO_LINE_DIRECTION_OUT given the respective
register base addresses configuration.

Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Acked-by: Michael Walle <michael@walle.cc>
Signed-off-by: William Breathitt Gray <william.gray@linaro.org>
---
 drivers/gpio/gpio-regmap.c | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/drivers/gpio/gpio-regmap.c b/drivers/gpio/gpio-regmap.c
index 6383136cbe59..f907c9c19fce 100644
--- a/drivers/gpio/gpio-regmap.c
+++ b/drivers/gpio/gpio-regmap.c
@@ -111,6 +111,11 @@ static int gpio_regmap_get_direction(struct gpio_chip *chip,
 	unsigned int base, val, reg, mask;
 	int invert, ret;
 
+	if (gpio->reg_dat_base && !gpio->reg_set_base)
+		return GPIO_LINE_DIRECTION_IN;
+	if (gpio->reg_set_base && !gpio->reg_dat_base)
+		return GPIO_LINE_DIRECTION_OUT;
+
 	if (gpio->reg_dir_out_base) {
 		base = gpio_regmap_addr(gpio->reg_dir_out_base);
 		invert = 0;
@@ -265,8 +270,8 @@ struct gpio_regmap *gpio_regmap_register(const struct gpio_regmap_config *config
 	else if (gpio->reg_set_base)
 		chip->set = gpio_regmap_set;
 
+	chip->get_direction = gpio_regmap_get_direction;
 	if (gpio->reg_dir_in_base || gpio->reg_dir_out_base) {
-		chip->get_direction = gpio_regmap_get_direction;
 		chip->direction_input = gpio_regmap_direction_input;
 		chip->direction_output = gpio_regmap_direction_output;
 	}
-- 
2.38.1

[PATCH v4 2/9] regmap-irq: Add handle_mask_sync() callback

[William Breathitt Gray]

Provide a public callback handle_mask_sync() that drivers can use when
they have more complex IRQ masking logic. The default implementation is
regmap_irq_handle_mask_sync(), used if the chip doesn't provide its own
callback.

Signed-off-by: William Breathitt Gray <william.gray@linaro.org>
---
 drivers/base/regmap/regmap-irq.c | 44 ++++++++++++++++++++++----------
 include/linux/regmap.h           |  5 ++++
 2 files changed, 36 insertions(+), 13 deletions(-)

diff --git a/drivers/base/regmap/regmap-irq.c b/drivers/base/regmap/regmap-irq.c
index 4ef9488d05cd..968681fa8d09 100644
--- a/drivers/base/regmap/regmap-irq.c
+++ b/drivers/base/regmap/regmap-irq.c
@@ -115,12 +115,20 @@ static void regmap_irq_sync_unlock(struct irq_data *data)
 	 */
 	for (i = 0; i < d->chip->num_regs; i++) {
 		if (d->mask_base) {
-			reg = d->get_irq_reg(d, d->mask_base, i);
-			ret = regmap_update_bits(d->map, reg,
-					d->mask_buf_def[i], d->mask_buf[i]);
-			if (ret)
-				dev_err(d->map->dev, "Failed to sync masks in %x\n",
-					reg);
+			if (d->chip->handle_mask_sync)
+				d->chip->handle_mask_sync(d->map, i,
+							  d->mask_buf_def[i],
+							  d->mask_buf[i],
+							  d->chip->irq_drv_data);
+			else {
+				reg = d->get_irq_reg(d, d->mask_base, i);
+				ret = regmap_update_bits(d->map, reg,
+						d->mask_buf_def[i],
+						d->mask_buf[i]);
+				if (ret)
+					dev_err(d->map->dev, "Failed to sync masks in %x\n",
+						reg);
+			}
 		}
 
 		if (d->unmask_base) {
@@ -917,13 +925,23 @@ int regmap_add_irq_chip_fwnode(struct fwnode_handle *fwnode,
 		d->mask_buf[i] = d->mask_buf_def[i];
 
 		if (d->mask_base) {
-			reg = d->get_irq_reg(d, d->mask_base, i);
-			ret = regmap_update_bits(d->map, reg,
-					d->mask_buf_def[i], d->mask_buf[i]);
-			if (ret) {
-				dev_err(map->dev, "Failed to set masks in 0x%x: %d\n",
-					reg, ret);
-				goto err_alloc;
+			if (chip->handle_mask_sync) {
+				ret = chip->handle_mask_sync(d->map, i,
+							     d->mask_buf_def[i],
+							     d->mask_buf[i],
+							     chip->irq_drv_data);
+				if (ret)
+					goto err_alloc;
+			} else {
+				reg = d->get_irq_reg(d, d->mask_base, i);
+				ret = regmap_update_bits(d->map, reg,
+						d->mask_buf_def[i],
+						d->mask_buf[i]);
+				if (ret) {
+					dev_err(map->dev, "Failed to set masks in 0x%x: %d\n",
+						reg, ret);
+					goto err_alloc;
+				}
 			}
 		}
 
diff --git a/include/linux/regmap.h b/include/linux/regmap.h
index ca3434dca3a0..cc07645501af 100644
--- a/include/linux/regmap.h
+++ b/include/linux/regmap.h
@@ -1542,6 +1542,8 @@ struct regmap_irq_chip_data;
  *		     before regmap_irq_handler process the interrupts.
  * @handle_post_irq: Driver specific callback to handle interrupt from device
  *		     after handling the interrupts in regmap_irq_handler().
+ * @handle_mask_sync: Callback used to handle IRQ mask syncs. The index will be
+ *		      in the range [0, num_regs)
  * @set_type_virt:   Driver specific callback to extend regmap_irq_set_type()
  *		     and configure virt regs. Deprecated, use @set_type_config
  *		     callback and config registers instead.
@@ -1603,6 +1605,9 @@ struct regmap_irq_chip {
 
 	int (*handle_pre_irq)(void *irq_drv_data);
 	int (*handle_post_irq)(void *irq_drv_data);
+	int (*handle_mask_sync)(struct regmap *map, int index,
+				unsigned int mask_buf_def,
+				unsigned int mask_buf, void *irq_drv_data);
 	int (*set_type_virt)(unsigned int **buf, unsigned int type,
 			     unsigned long hwirq, int reg);
 	int (*set_type_config)(unsigned int **buf, unsigned int type,
-- 
2.38.1

[PATCH v4 3/9] gpio: 104-dio-48e: Migrate to the regmap-irq API

[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.

For the 104-dio-48e we have the following IRQ registers (0xB and 0xF):

    Base Address +B (Write): Enable Interrupt
    Base Address +B (Read): Disable Interrupt
    Base Address +F (Read/Write): Clear Interrupt

Any write to 0xB will enable interrupts, while any read will disable
interrupts. Interrupts are cleared by a read or any write to 0xF.
There's no IRQ status register, so software has to assume that if an
interrupt is raised then it was for the 104-DIO-48E device.

Signed-off-by: William Breathitt Gray <william.gray@linaro.org>
---
 drivers/gpio/Kconfig            |   1 +
 drivers/gpio/gpio-104-dio-48e.c | 268 +++++++++++++++-----------------
 2 files changed, 127 insertions(+), 142 deletions(-)

diff --git a/drivers/gpio/Kconfig b/drivers/gpio/Kconfig
index ec7cfd4f52b1..b62bef4e563d 100644
--- a/drivers/gpio/Kconfig
+++ b/drivers/gpio/Kconfig
@@ -845,6 +845,7 @@ config GPIO_104_DIO_48E
 	tristate "ACCES 104-DIO-48E GPIO support"
 	depends on PC104
 	select ISA_BUS_API
+	select REGMAP_IRQ
 	select GPIOLIB_IRQCHIP
 	select GPIO_I8255
 	help
diff --git a/drivers/gpio/gpio-104-dio-48e.c b/drivers/gpio/gpio-104-dio-48e.c
index 7b8829c8e423..4c3660d5dea5 100644
--- a/drivers/gpio/gpio-104-dio-48e.c
+++ b/drivers/gpio/gpio-104-dio-48e.c
@@ -8,17 +8,15 @@
  */
 #include <linux/bits.h>
 #include <linux/device.h>
-#include <linux/errno.h>
+#include <linux/err.h>
 #include <linux/gpio/driver.h>
-#include <linux/io.h>
 #include <linux/ioport.h>
-#include <linux/interrupt.h>
-#include <linux/irqdesc.h>
+#include <linux/irq.h>
 #include <linux/isa.h>
 #include <linux/kernel.h>
 #include <linux/module.h>
 #include <linux/moduleparam.h>
-#include <linux/spinlock.h>
+#include <linux/regmap.h>
 #include <linux/types.h>
 
 #include "gpio-i8255.h"
@@ -38,46 +36,30 @@ static unsigned int num_irq;
 module_param_hw_array(irq, uint, irq, &num_irq, 0);
 MODULE_PARM_DESC(irq, "ACCES 104-DIO-48E interrupt line numbers");
 
+#define DIO48E_ENABLE_INTERRUPT 0xB
+#define DIO48E_DISABLE_INTERRUPT DIO48E_ENABLE_INTERRUPT
+#define DIO48E_CLEAR_INTERRUPT 0xF
+
 #define DIO48E_NUM_PPI 2
 
 /**
  * struct dio48e_reg - device register structure
  * @ppi:		Programmable Peripheral Interface groups
- * @enable_buffer:	Enable/Disable Buffer groups
- * @unused1:		Unused
- * @enable_interrupt:	Write: Enable Interrupt
- *			Read: Disable Interrupt
- * @unused2:		Unused
- * @enable_counter:	Write: Enable Counter/Timer Addressing
- *			Read: Disable Counter/Timer Addressing
- * @unused3:		Unused
- * @clear_interrupt:	Clear Interrupt
  */
 struct dio48e_reg {
 	struct i8255 ppi[DIO48E_NUM_PPI];
-	u8 enable_buffer[DIO48E_NUM_PPI];
-	u8 unused1;
-	u8 enable_interrupt;
-	u8 unused2;
-	u8 enable_counter;
-	u8 unused3;
-	u8 clear_interrupt;
 };
 
 /**
  * struct dio48e_gpio - GPIO device private data structure
  * @chip:		instance of the gpio_chip
  * @ppi_state:		PPI device states
- * @lock:		synchronization lock to prevent I/O race conditions
  * @reg:		I/O address offset for the device registers
- * @irq_mask:		I/O bits affected by interrupts
  */
 struct dio48e_gpio {
 	struct gpio_chip chip;
 	struct i8255_state ppi_state[DIO48E_NUM_PPI];
-	raw_spinlock_t lock;
 	struct dio48e_reg __iomem *reg;
-	unsigned char irq_mask;
 };
 
 static int dio48e_gpio_get_direction(struct gpio_chip *chip, unsigned int offset)
@@ -144,106 +126,90 @@ static void dio48e_gpio_set_multiple(struct gpio_chip *chip,
 			   bits, chip->ngpio);
 }
 
-static void dio48e_irq_ack(struct irq_data *data)
-{
-}
-
-static void dio48e_irq_mask(struct irq_data *data)
-{
-	struct gpio_chip *chip = irq_data_get_irq_chip_data(data);
-	struct dio48e_gpio *const dio48egpio = gpiochip_get_data(chip);
-	const unsigned long offset = irqd_to_hwirq(data);
-	unsigned long flags;
-
-	/* only bit 3 on each respective Port C supports interrupts */
-	if (offset != 19 && offset != 43)
-		return;
-
-	raw_spin_lock_irqsave(&dio48egpio->lock, flags);
-
-	if (offset == 19)
-		dio48egpio->irq_mask &= ~BIT(0);
-	else
-		dio48egpio->irq_mask &= ~BIT(1);
-	gpiochip_disable_irq(chip, offset);
-
-	if (!dio48egpio->irq_mask)
-		/* disable interrupts */
-		ioread8(&dio48egpio->reg->enable_interrupt);
-
-	raw_spin_unlock_irqrestore(&dio48egpio->lock, flags);
-}
-
-static void dio48e_irq_unmask(struct irq_data *data)
-{
-	struct gpio_chip *chip = irq_data_get_irq_chip_data(data);
-	struct dio48e_gpio *const dio48egpio = gpiochip_get_data(chip);
-	const unsigned long offset = irqd_to_hwirq(data);
-	unsigned long flags;
-
-	/* only bit 3 on each respective Port C supports interrupts */
-	if (offset != 19 && offset != 43)
-		return;
-
-	raw_spin_lock_irqsave(&dio48egpio->lock, flags);
+static const struct regmap_range dio48e_wr_ranges[] = {
+	regmap_reg_range(0x0, 0x9), regmap_reg_range(0xB, 0xB),
+	regmap_reg_range(0xD, 0xD), regmap_reg_range(0xF, 0xF),
+};
+static const struct regmap_range dio48e_rd_ranges[] = {
+	regmap_reg_range(0x0, 0x2), regmap_reg_range(0x4, 0x6),
+	regmap_reg_range(0xB, 0xB), regmap_reg_range(0xD, 0xD),
+	regmap_reg_range(0xF, 0xF),
+};
+static const struct regmap_range dio48e_volatile_ranges[] = {
+	i8255_volatile_regmap_range(0x0), i8255_volatile_regmap_range(0x4),
+	regmap_reg_range(0xB, 0xB), regmap_reg_range(0xD, 0xD),
+	regmap_reg_range(0xF, 0xF),
+};
+static const struct regmap_range dio48e_precious_ranges[] = {
+	regmap_reg_range(0xB, 0xB), regmap_reg_range(0xD, 0xD),
+	regmap_reg_range(0xF, 0xF),
+};
+static const struct regmap_access_table dio48e_wr_table = {
+	.yes_ranges = dio48e_wr_ranges,
+	.n_yes_ranges = ARRAY_SIZE(dio48e_wr_ranges),
+};
+static const struct regmap_access_table dio48e_rd_table = {
+	.yes_ranges = dio48e_rd_ranges,
+	.n_yes_ranges = ARRAY_SIZE(dio48e_rd_ranges),
+};
+static const struct regmap_access_table dio48e_volatile_table = {
+	.yes_ranges = dio48e_volatile_ranges,
+	.n_yes_ranges = ARRAY_SIZE(dio48e_volatile_ranges),
+};
+static const struct regmap_access_table dio48e_precious_table = {
+	.yes_ranges = dio48e_precious_ranges,
+	.n_yes_ranges = ARRAY_SIZE(dio48e_precious_ranges),
+};
+static const struct regmap_config dio48e_regmap_config = {
+	.reg_bits = 8,
+	.reg_stride = 1,
+	.val_bits = 8,
+	.io_port = true,
+	.max_register = 0xF,
+	.wr_table = &dio48e_wr_table,
+	.rd_table = &dio48e_rd_table,
+	.volatile_table = &dio48e_volatile_table,
+	.precious_table = &dio48e_precious_table,
+	.cache_type = REGCACHE_FLAT,
+};
 
-	if (!dio48egpio->irq_mask) {
-		/* enable interrupts */
-		iowrite8(0x00, &dio48egpio->reg->clear_interrupt);
-		iowrite8(0x00, &dio48egpio->reg->enable_interrupt);
+/* only bit 3 on each respective Port C supports interrupts */
+#define DIO48E_REGMAP_IRQ(_ppi)						\
+	[19 + (_ppi) * 24] = {						\
+		.mask = BIT(_ppi),					\
+		.type = { .types_supported = IRQ_TYPE_EDGE_RISING },	\
 	}
 
-	gpiochip_enable_irq(chip, offset);
-	if (offset == 19)
-		dio48egpio->irq_mask |= BIT(0);
-	else
-		dio48egpio->irq_mask |= BIT(1);
-
-	raw_spin_unlock_irqrestore(&dio48egpio->lock, flags);
-}
-
-static int dio48e_irq_set_type(struct irq_data *data, unsigned int flow_type)
-{
-	const unsigned long offset = irqd_to_hwirq(data);
-
-	/* only bit 3 on each respective Port C supports interrupts */
-	if (offset != 19 && offset != 43)
-		return -EINVAL;
-
-	if (flow_type != IRQ_TYPE_NONE && flow_type != IRQ_TYPE_EDGE_RISING)
-		return -EINVAL;
-
-	return 0;
-}
-
-static const struct irq_chip dio48e_irqchip = {
-	.name = "104-dio-48e",
-	.irq_ack = dio48e_irq_ack,
-	.irq_mask = dio48e_irq_mask,
-	.irq_unmask = dio48e_irq_unmask,
-	.irq_set_type = dio48e_irq_set_type,
-	.flags = IRQCHIP_IMMUTABLE,
-	GPIOCHIP_IRQ_RESOURCE_HELPERS,
+static const struct regmap_irq dio48e_regmap_irqs[] = {
+	DIO48E_REGMAP_IRQ(0), DIO48E_REGMAP_IRQ(1),
 };
 
-static irqreturn_t dio48e_irq_handler(int irq, void *dev_id)
+static int dio48e_handle_mask_sync(struct regmap *const map, const int index,
+				   const unsigned int mask_buf_def,
+				   const unsigned int mask_buf,
+				   void *const irq_drv_data)
 {
-	struct dio48e_gpio *const dio48egpio = dev_id;
-	struct gpio_chip *const chip = &dio48egpio->chip;
-	const unsigned long irq_mask = dio48egpio->irq_mask;
-	unsigned long gpio;
+	unsigned int *const irq_mask = irq_drv_data;
+	const unsigned int prev_mask = *irq_mask;
+	const unsigned int all_masked = 0x3;
+	unsigned int val;
 
-	for_each_set_bit(gpio, &irq_mask, 2)
-		generic_handle_domain_irq(chip->irq.domain,
-					  19 + gpio*24);
+	/* exit early if no change since the previous mask */
+	if (mask_buf == prev_mask)
+		return 0;
 
-	raw_spin_lock(&dio48egpio->lock);
+	/* remember the current mask for the next mask sync */
+	*irq_mask = mask_buf;
 
-	iowrite8(0x00, &dio48egpio->reg->clear_interrupt);
+	/* if all previously masked, enable interrupts when unmasking */
+	if (prev_mask == all_masked)
+		return regmap_write(map, DIO48E_ENABLE_INTERRUPT, 0x00);
 
-	raw_spin_unlock(&dio48egpio->lock);
+	/* if all are currently masked, disable interrupts */
+	if (mask_buf == all_masked)
+		return regmap_read(map, DIO48E_DISABLE_INTERRUPT, &val);
 
-	return IRQ_HANDLED;
+	return 0;
 }
 
 #define DIO48E_NGPIO 48
@@ -266,14 +232,12 @@ static const char *dio48e_names[DIO48E_NGPIO] = {
 	"PPI Group 1 Port C 5", "PPI Group 1 Port C 6", "PPI Group 1 Port C 7"
 };
 
-static int dio48e_irq_init_hw(struct gpio_chip *gc)
+static int dio48e_irq_init_hw(struct regmap *const map)
 {
-	struct dio48e_gpio *const dio48egpio = gpiochip_get_data(gc);
+	unsigned int val;
 
 	/* Disable IRQ by default */
-	ioread8(&dio48egpio->reg->enable_interrupt);
-
-	return 0;
+	return regmap_read(map, DIO48E_DISABLE_INTERRUPT, &val);
 }
 
 static void dio48e_init_ppi(struct i8255 __iomem *const ppi,
@@ -295,8 +259,12 @@ static int dio48e_probe(struct device *dev, unsigned int id)
 {
 	struct dio48e_gpio *dio48egpio;
 	const char *const name = dev_name(dev);
-	struct gpio_irq_chip *girq;
+	void __iomem *regs;
+	struct regmap *map;
 	int err;
+	struct regmap_irq_chip *chip;
+	unsigned int irq_mask;
+	struct regmap_irq_chip_data *chip_data;
 
 	dio48egpio = devm_kzalloc(dev, sizeof(*dio48egpio), GFP_KERNEL);
 	if (!dio48egpio)
@@ -308,9 +276,43 @@ static int dio48e_probe(struct device *dev, unsigned int id)
 		return -EBUSY;
 	}
 
-	dio48egpio->reg = devm_ioport_map(dev, base[id], DIO48E_EXTENT);
-	if (!dio48egpio->reg)
+	regs = devm_ioport_map(dev, base[id], DIO48E_EXTENT);
+	if (!regs)
 		return -ENOMEM;
+	dio48egpio->reg = regs;
+
+	map = devm_regmap_init_mmio(dev, regs, &dio48e_regmap_config);
+	if (IS_ERR(map))
+		return dev_err_probe(dev, PTR_ERR(map),
+				     "Unable to initialize register map\n");
+
+	chip = devm_kzalloc(dev, sizeof(*chip), GFP_KERNEL);
+	if (!chip)
+		return -ENOMEM;
+
+	chip->irq_drv_data = devm_kzalloc(dev, sizeof(irq_mask), GFP_KERNEL);
+	if (!chip->irq_drv_data)
+		return -ENOMEM;
+
+	chip->name = name;
+	/* No IRQ status register so use CLEAR_INTERRUPT register instead */
+	chip->status_base = DIO48E_CLEAR_INTERRUPT;
+	chip->mask_base = DIO48E_ENABLE_INTERRUPT;
+	chip->clear_on_unmask = true;
+	chip->status_invert = true;
+	chip->num_regs = 1;
+	chip->irqs = dio48e_regmap_irqs;
+	chip->num_irqs = ARRAY_SIZE(dio48e_regmap_irqs);
+	chip->handle_mask_sync = dio48e_handle_mask_sync;
+
+	/* Initialize to prevent spurious interrupts before we're ready */
+	err = dio48e_irq_init_hw(map);
+	if (err)
+		return err;
+
+	err = devm_regmap_add_irq_chip(dev, map, irq[id], 0, 0, chip, &chip_data);
+	if (err)
+		return dev_err_probe(dev, err, "IRQ registration failed\n");
 
 	dio48egpio->chip.label = name;
 	dio48egpio->chip.parent = dev;
@@ -326,18 +328,6 @@ static int dio48e_probe(struct device *dev, unsigned int id)
 	dio48egpio->chip.set = dio48e_gpio_set;
 	dio48egpio->chip.set_multiple = dio48e_gpio_set_multiple;
 
-	girq = &dio48egpio->chip.irq;
-	gpio_irq_chip_set_chip(girq, &dio48e_irqchip);
-	/* This will let us handle the parent IRQ in the driver */
-	girq->parent_handler = NULL;
-	girq->num_parents = 0;
-	girq->parents = NULL;
-	girq->default_type = IRQ_TYPE_NONE;
-	girq->handler = handle_edge_irq;
-	girq->init_hw = dio48e_irq_init_hw;
-
-	raw_spin_lock_init(&dio48egpio->lock);
-
 	i8255_state_init(dio48egpio->ppi_state, DIO48E_NUM_PPI);
 	dio48e_init_ppi(dio48egpio->reg->ppi, dio48egpio->ppi_state);
 
@@ -347,14 +337,8 @@ static int dio48e_probe(struct device *dev, unsigned int id)
 		return err;
 	}
 
-	err = devm_request_irq(dev, irq[id], dio48e_irq_handler, 0, name,
-		dio48egpio);
-	if (err) {
-		dev_err(dev, "IRQ handler registering failed (%d)\n", err);
-		return err;
-	}
-
-	return 0;
+	return gpiochip_irqchip_add_domain(&dio48egpio->chip,
+					   regmap_irq_get_domain(chip_data));
 }
 
 static struct isa_driver dio48e_driver = {
-- 
2.38.1

[PATCH v4 4/9] gpio: 104-idi-48: Migrate to the regmap-irq API

[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.

For the 104-idi-48, we get an IRQ register with some status information
and basic masking, but it's broken down by banks rather than individual
GPIO. There are six banks (8 GPIO lines each) that correspond to the
lower six bits of the IRQ register (bits 0-5):

    Base Address + 7 (Read): IRQ Status Register/IRQ Clear
        Bit 0-5: Respective Bank IRQ Statuses
        Bit 6: IRQ Status (Active Low)
        Bit 7: IRQ Enable Status
    Base Address + 7 (Write): IRQ Enable/Disable
        Bit 0-5: Respective Bank IRQ Enable/Disable

Signed-off-by: William Breathitt Gray <william.gray@linaro.org>
---
 drivers/gpio/Kconfig           |   1 +
 drivers/gpio/gpio-104-idi-48.c | 249 ++++++++++++---------------------
 2 files changed, 92 insertions(+), 158 deletions(-)

diff --git a/drivers/gpio/Kconfig b/drivers/gpio/Kconfig
index b62bef4e563d..6892979e511a 100644
--- a/drivers/gpio/Kconfig
+++ b/drivers/gpio/Kconfig
@@ -871,6 +871,7 @@ config GPIO_104_IDI_48
 	tristate "ACCES 104-IDI-48 GPIO support"
 	depends on PC104
 	select ISA_BUS_API
+	select REGMAP_IRQ
 	select GPIOLIB_IRQCHIP
 	select GPIO_I8255
 	help
diff --git a/drivers/gpio/gpio-104-idi-48.c b/drivers/gpio/gpio-104-idi-48.c
index c5e231fde1af..f936e3e0ff12 100644
--- a/drivers/gpio/gpio-104-idi-48.c
+++ b/drivers/gpio/gpio-104-idi-48.c
@@ -8,17 +8,16 @@
  */
 #include <linux/bits.h>
 #include <linux/device.h>
-#include <linux/errno.h>
+#include <linux/err.h>
 #include <linux/gpio/driver.h>
-#include <linux/io.h>
-#include <linux/ioport.h>
 #include <linux/interrupt.h>
-#include <linux/irqdesc.h>
+#include <linux/ioport.h>
+#include <linux/irq.h>
 #include <linux/isa.h>
 #include <linux/kernel.h>
 #include <linux/module.h>
 #include <linux/moduleparam.h>
-#include <linux/spinlock.h>
+#include <linux/regmap.h>
 #include <linux/types.h>
 
 #include "gpio-i8255.h"
@@ -38,6 +37,9 @@ static unsigned int num_irq;
 module_param_hw_array(irq, uint, irq, &num_irq, 0);
 MODULE_PARM_DESC(irq, "ACCES 104-IDI-48 interrupt line numbers");
 
+#define IDI48_IRQ_STATUS 0x7
+#define IDI48_IRQ_ENABLE IDI48_IRQ_STATUS
+
 /**
  * struct idi_48_reg - device register structure
  * @port0:	Port 0 Inputs
@@ -56,17 +58,11 @@ struct idi_48_reg {
 /**
  * struct idi_48_gpio - GPIO device private data structure
  * @chip:	instance of the gpio_chip
- * @lock:	synchronization lock to prevent I/O race conditions
- * @irq_mask:	input bits affected by interrupts
  * @reg:	I/O address offset for the device registers
- * @cos_enb:	Change-Of-State IRQ enable boundaries mask
  */
 struct idi_48_gpio {
 	struct gpio_chip chip;
-	spinlock_t lock;
-	unsigned char irq_mask[6];
 	struct idi_48_reg __iomem *reg;
-	unsigned char cos_enb;
 };
 
 static int idi_48_gpio_get_direction(struct gpio_chip *chip, unsigned int offset)
@@ -98,125 +94,65 @@ static int idi_48_gpio_get_multiple(struct gpio_chip *chip, unsigned long *mask,
 	return 0;
 }
 
-static void idi_48_irq_ack(struct irq_data *data)
-{
-}
-
-static void idi_48_irq_mask(struct irq_data *data)
-{
-	struct gpio_chip *chip = irq_data_get_irq_chip_data(data);
-	struct idi_48_gpio *const idi48gpio = gpiochip_get_data(chip);
-	const unsigned int offset = irqd_to_hwirq(data);
-	const unsigned long boundary = offset / 8;
-	const unsigned long mask = BIT(offset % 8);
-	unsigned long flags;
-
-	spin_lock_irqsave(&idi48gpio->lock, flags);
-
-	idi48gpio->irq_mask[boundary] &= ~mask;
-	gpiochip_disable_irq(chip, offset);
-
-	/* Exit early if there are still input lines with IRQ unmasked */
-	if (idi48gpio->irq_mask[boundary])
-		goto exit;
-
-	idi48gpio->cos_enb &= ~BIT(boundary);
-
-	iowrite8(idi48gpio->cos_enb, &idi48gpio->reg->irq);
-
-exit:
-	spin_unlock_irqrestore(&idi48gpio->lock, flags);
-}
-
-static void idi_48_irq_unmask(struct irq_data *data)
-{
-	struct gpio_chip *chip = irq_data_get_irq_chip_data(data);
-	struct idi_48_gpio *const idi48gpio = gpiochip_get_data(chip);
-	const unsigned int offset = irqd_to_hwirq(data);
-	const unsigned long boundary = offset / 8;
-	const unsigned long mask = BIT(offset % 8);
-	unsigned int prev_irq_mask;
-	unsigned long flags;
-
-	spin_lock_irqsave(&idi48gpio->lock, flags);
-
-	prev_irq_mask = idi48gpio->irq_mask[boundary];
-
-	gpiochip_enable_irq(chip, offset);
-	idi48gpio->irq_mask[boundary] |= mask;
-
-	/* Exit early if IRQ was already unmasked for this boundary */
-	if (prev_irq_mask)
-		goto exit;
-
-	idi48gpio->cos_enb |= BIT(boundary);
-
-	iowrite8(idi48gpio->cos_enb, &idi48gpio->reg->irq);
-
-exit:
-	spin_unlock_irqrestore(&idi48gpio->lock, flags);
-}
-
-static int idi_48_irq_set_type(struct irq_data *data, unsigned int flow_type)
-{
-	/* The only valid irq types are none and both-edges */
-	if (flow_type != IRQ_TYPE_NONE &&
-		(flow_type & IRQ_TYPE_EDGE_BOTH) != IRQ_TYPE_EDGE_BOTH)
-		return -EINVAL;
-
-	return 0;
-}
-
-static const struct irq_chip idi_48_irqchip = {
-	.name = "104-idi-48",
-	.irq_ack = idi_48_irq_ack,
-	.irq_mask = idi_48_irq_mask,
-	.irq_unmask = idi_48_irq_unmask,
-	.irq_set_type = idi_48_irq_set_type,
-	.flags = IRQCHIP_IMMUTABLE,
-	GPIOCHIP_IRQ_RESOURCE_HELPERS,
+static const struct regmap_range idi_48_wr_ranges[] = {
+	regmap_reg_range(0x0, 0x6),
+};
+static const struct regmap_range idi_48_rd_ranges[] = {
+	regmap_reg_range(0x0, 0x2), regmap_reg_range(0x4, 0x7),
+};
+static const struct regmap_range idi_48_precious_ranges[] = {
+	regmap_reg_range(0x7, 0x7),
+};
+static const struct regmap_access_table idi_48_wr_table = {
+	.no_ranges = idi_48_wr_ranges,
+	.n_no_ranges = ARRAY_SIZE(idi_48_wr_ranges),
+};
+static const struct regmap_access_table idi_48_rd_table = {
+	.yes_ranges = idi_48_rd_ranges,
+	.n_yes_ranges = ARRAY_SIZE(idi_48_rd_ranges),
+};
+static const struct regmap_access_table idi_48_precious_table = {
+	.yes_ranges = idi_48_precious_ranges,
+	.n_yes_ranges = ARRAY_SIZE(idi_48_precious_ranges),
+};
+static const struct regmap_config idi48_regmap_config = {
+	.reg_bits = 8,
+	.reg_stride = 1,
+	.val_bits = 8,
+	.io_port = true,
+	.max_register = 0x6,
+	.wr_table = &idi_48_wr_table,
+	.rd_table = &idi_48_rd_table,
+	.precious_table = &idi_48_precious_table,
 };
 
-static irqreturn_t idi_48_irq_handler(int irq, void *dev_id)
-{
-	struct idi_48_gpio *const idi48gpio = dev_id;
-	unsigned long cos_status;
-	unsigned long boundary;
-	unsigned long irq_mask;
-	unsigned long bit_num;
-	unsigned long gpio;
-	struct gpio_chip *const chip = &idi48gpio->chip;
-
-	spin_lock(&idi48gpio->lock);
-
-	cos_status = ioread8(&idi48gpio->reg->irq);
-
-	/* IRQ Status (bit 6) is active low (0 = IRQ generated by device) */
-	if (cos_status & BIT(6)) {
-		spin_unlock(&idi48gpio->lock);
-		return IRQ_NONE;
-	}
-
-	/* Bit 0-5 indicate which Change-Of-State boundary triggered the IRQ */
-	cos_status &= 0x3F;
-
-	for_each_set_bit(boundary, &cos_status, 6) {
-		irq_mask = idi48gpio->irq_mask[boundary];
-
-		for_each_set_bit(bit_num, &irq_mask, 8) {
-			gpio = bit_num + boundary * 8;
+#define IDI48_NGPIO 48
 
-			generic_handle_domain_irq(chip->irq.domain,
-						  gpio);
-		}
+#define IDI48_REGMAP_IRQ(_id)						\
+	[_id] = {							\
+		.mask = BIT((_id) / 8),					\
+		.type = { .types_supported = IRQ_TYPE_EDGE_BOTH },	\
 	}
 
-	spin_unlock(&idi48gpio->lock);
-
-	return IRQ_HANDLED;
-}
+static const struct regmap_irq idi48_regmap_irqs[IDI48_NGPIO] = {
+	IDI48_REGMAP_IRQ(0), IDI48_REGMAP_IRQ(1), IDI48_REGMAP_IRQ(2), /* 0-2 */
+	IDI48_REGMAP_IRQ(3), IDI48_REGMAP_IRQ(4), IDI48_REGMAP_IRQ(5), /* 3-5 */
+	IDI48_REGMAP_IRQ(6), IDI48_REGMAP_IRQ(7), IDI48_REGMAP_IRQ(8), /* 6-8 */
+	IDI48_REGMAP_IRQ(9), IDI48_REGMAP_IRQ(10), IDI48_REGMAP_IRQ(11), /* 9-11 */
+	IDI48_REGMAP_IRQ(12), IDI48_REGMAP_IRQ(13), IDI48_REGMAP_IRQ(14), /* 12-14 */
+	IDI48_REGMAP_IRQ(15), IDI48_REGMAP_IRQ(16), IDI48_REGMAP_IRQ(17), /* 15-17 */
+	IDI48_REGMAP_IRQ(18), IDI48_REGMAP_IRQ(19), IDI48_REGMAP_IRQ(20), /* 18-20 */
+	IDI48_REGMAP_IRQ(21), IDI48_REGMAP_IRQ(22), IDI48_REGMAP_IRQ(23), /* 21-23 */
+	IDI48_REGMAP_IRQ(24), IDI48_REGMAP_IRQ(25), IDI48_REGMAP_IRQ(26), /* 24-26 */
+	IDI48_REGMAP_IRQ(27), IDI48_REGMAP_IRQ(28), IDI48_REGMAP_IRQ(29), /* 27-29 */
+	IDI48_REGMAP_IRQ(30), IDI48_REGMAP_IRQ(31), IDI48_REGMAP_IRQ(32), /* 30-32 */
+	IDI48_REGMAP_IRQ(33), IDI48_REGMAP_IRQ(34), IDI48_REGMAP_IRQ(35), /* 33-35 */
+	IDI48_REGMAP_IRQ(36), IDI48_REGMAP_IRQ(37), IDI48_REGMAP_IRQ(38), /* 36-38 */
+	IDI48_REGMAP_IRQ(39), IDI48_REGMAP_IRQ(40), IDI48_REGMAP_IRQ(41), /* 39-41 */
+	IDI48_REGMAP_IRQ(42), IDI48_REGMAP_IRQ(43), IDI48_REGMAP_IRQ(44), /* 42-44 */
+	IDI48_REGMAP_IRQ(45), IDI48_REGMAP_IRQ(46), IDI48_REGMAP_IRQ(47), /* 45-47 */
+};
 
-#define IDI48_NGPIO 48
 static const char *idi48_names[IDI48_NGPIO] = {
 	"Bit 0 A", "Bit 1 A", "Bit 2 A", "Bit 3 A", "Bit 4 A", "Bit 5 A",
 	"Bit 6 A", "Bit 7 A", "Bit 8 A", "Bit 9 A", "Bit 10 A", "Bit 11 A",
@@ -228,22 +164,14 @@ static const char *idi48_names[IDI48_NGPIO] = {
 	"Bit 18 B", "Bit 19 B", "Bit 20 B", "Bit 21 B", "Bit 22 B", "Bit 23 B"
 };
 
-static int idi_48_irq_init_hw(struct gpio_chip *gc)
-{
-	struct idi_48_gpio *const idi48gpio = gpiochip_get_data(gc);
-
-	/* Disable IRQ by default */
-	iowrite8(0, &idi48gpio->reg->irq);
-	ioread8(&idi48gpio->reg->irq);
-
-	return 0;
-}
-
 static int idi_48_probe(struct device *dev, unsigned int id)
 {
 	struct idi_48_gpio *idi48gpio;
 	const char *const name = dev_name(dev);
-	struct gpio_irq_chip *girq;
+	void __iomem *regs;
+	struct regmap *map;
+	struct regmap_irq_chip *chip;
+	struct regmap_irq_chip_data *chip_data;
 	int err;
 
 	idi48gpio = devm_kzalloc(dev, sizeof(*idi48gpio), GFP_KERNEL);
@@ -256,9 +184,32 @@ static int idi_48_probe(struct device *dev, unsigned int id)
 		return -EBUSY;
 	}
 
-	idi48gpio->reg = devm_ioport_map(dev, base[id], IDI_48_EXTENT);
-	if (!idi48gpio->reg)
+	regs = devm_ioport_map(dev, base[id], IDI_48_EXTENT);
+	if (!regs)
 		return -ENOMEM;
+	idi48gpio->reg = regs;
+
+	map = devm_regmap_init_mmio(dev, regs, &idi48_regmap_config);
+	if (IS_ERR(map))
+		return dev_err_probe(dev, PTR_ERR(map),
+				     "Unable to initialize register map\n");
+
+	chip = devm_kzalloc(dev, sizeof(*chip), GFP_KERNEL);
+	if (!chip)
+		return -ENOMEM;
+
+	chip->name = name;
+	chip->status_base = IDI48_IRQ_STATUS;
+	chip->unmask_base = IDI48_IRQ_ENABLE;
+	chip->clear_on_unmask = true;
+	chip->num_regs = 1;
+	chip->irqs = idi48_regmap_irqs;
+	chip->num_irqs = ARRAY_SIZE(idi48_regmap_irqs);
+
+	err = devm_regmap_add_irq_chip(dev, map, irq[id], IRQF_SHARED, 0, chip,
+				       &chip_data);
+	if (err)
+		return dev_err_probe(dev, err, "IRQ registration failed\n");
 
 	idi48gpio->chip.label = name;
 	idi48gpio->chip.parent = dev;
@@ -271,32 +222,14 @@ static int idi_48_probe(struct device *dev, unsigned int id)
 	idi48gpio->chip.get = idi_48_gpio_get;
 	idi48gpio->chip.get_multiple = idi_48_gpio_get_multiple;
 
-	girq = &idi48gpio->chip.irq;
-	gpio_irq_chip_set_chip(girq, &idi_48_irqchip);
-	/* This will let us handle the parent IRQ in the driver */
-	girq->parent_handler = NULL;
-	girq->num_parents = 0;
-	girq->parents = NULL;
-	girq->default_type = IRQ_TYPE_NONE;
-	girq->handler = handle_edge_irq;
-	girq->init_hw = idi_48_irq_init_hw;
-
-	spin_lock_init(&idi48gpio->lock);
-
 	err = devm_gpiochip_add_data(dev, &idi48gpio->chip, idi48gpio);
 	if (err) {
 		dev_err(dev, "GPIO registering failed (%d)\n", err);
 		return err;
 	}
 
-	err = devm_request_irq(dev, irq[id], idi_48_irq_handler, IRQF_SHARED,
-		name, idi48gpio);
-	if (err) {
-		dev_err(dev, "IRQ handler registering failed (%d)\n", err);
-		return err;
-	}
-
-	return 0;
+	return gpiochip_irqchip_add_domain(&idi48gpio->chip,
+					   regmap_irq_get_domain(chip_data));
 }
 
 static struct isa_driver idi_48_driver = {
-- 
2.38.1

[PATCH v4 5/9] gpio: 104-idi-48: Migrate to gpio-regmap API

[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. Despite the underlying interface being based on
i8255, it is simpler to use the gpio-regmap API directly because the
104-IDI-48 device features only input signals. Therefore, the dependence
on the i8255 GPIO library is removed in this patch.

Suggested-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: William Breathitt Gray <william.gray@linaro.org>
---
 drivers/gpio/Kconfig           |  2 +-
 drivers/gpio/gpio-104-idi-48.c | 97 +++++++---------------------------
 2 files changed, 21 insertions(+), 78 deletions(-)

diff --git a/drivers/gpio/Kconfig b/drivers/gpio/Kconfig
index 6892979e511a..dd34039fc31b 100644
--- a/drivers/gpio/Kconfig
+++ b/drivers/gpio/Kconfig
@@ -873,7 +873,7 @@ config GPIO_104_IDI_48
 	select ISA_BUS_API
 	select REGMAP_IRQ
 	select GPIOLIB_IRQCHIP
-	select GPIO_I8255
+	select GPIO_REGMAP
 	help
 	  Enables GPIO support for the ACCES 104-IDI-48 family (104-IDI-48A,
 	  104-IDI-48AC, 104-IDI-48B, 104-IDI-48BC). The base port addresses for
diff --git a/drivers/gpio/gpio-104-idi-48.c b/drivers/gpio/gpio-104-idi-48.c
index f936e3e0ff12..ca2175b84e24 100644
--- a/drivers/gpio/gpio-104-idi-48.c
+++ b/drivers/gpio/gpio-104-idi-48.c
@@ -9,7 +9,7 @@
 #include <linux/bits.h>
 #include <linux/device.h>
 #include <linux/err.h>
-#include <linux/gpio/driver.h>
+#include <linux/gpio/regmap.h>
 #include <linux/interrupt.h>
 #include <linux/ioport.h>
 #include <linux/irq.h>
@@ -20,10 +20,6 @@
 #include <linux/regmap.h>
 #include <linux/types.h>
 
-#include "gpio-i8255.h"
-
-MODULE_IMPORT_NS(I8255);
-
 #define IDI_48_EXTENT 8
 #define MAX_NUM_IDI_48 max_num_isa_dev(IDI_48_EXTENT)
 
@@ -40,56 +36,17 @@ MODULE_PARM_DESC(irq, "ACCES 104-IDI-48 interrupt line numbers");
 #define IDI48_IRQ_STATUS 0x7
 #define IDI48_IRQ_ENABLE IDI48_IRQ_STATUS
 
-/**
- * struct idi_48_reg - device register structure
- * @port0:	Port 0 Inputs
- * @unused:	Unused
- * @port1:	Port 1 Inputs
- * @irq:	Read: IRQ Status Register/IRQ Clear
- *		Write: IRQ Enable/Disable
- */
-struct idi_48_reg {
-	u8 port0[3];
-	u8 unused;
-	u8 port1[3];
-	u8 irq;
-};
-
-/**
- * struct idi_48_gpio - GPIO device private data structure
- * @chip:	instance of the gpio_chip
- * @reg:	I/O address offset for the device registers
- */
-struct idi_48_gpio {
-	struct gpio_chip chip;
-	struct idi_48_reg __iomem *reg;
-};
-
-static int idi_48_gpio_get_direction(struct gpio_chip *chip, unsigned int offset)
-{
-	return GPIO_LINE_DIRECTION_IN;
-}
-
-static int idi_48_gpio_direction_input(struct gpio_chip *chip, unsigned int offset)
+static int idi_48_reg_mask_xlate(struct gpio_regmap *gpio, unsigned int base,
+				 unsigned int offset, unsigned int *reg,
+				 unsigned int *mask)
 {
-	return 0;
-}
-
-static int idi_48_gpio_get(struct gpio_chip *chip, unsigned int offset)
-{
-	struct idi_48_gpio *const idi48gpio = gpiochip_get_data(chip);
-	void __iomem *const ppi = idi48gpio->reg;
+	const unsigned int line = offset % 8;
+	const unsigned int stride = offset / 8;
+	const unsigned int port = (stride / 3) * 4;
+	const unsigned int port_stride = stride % 3;
 
-	return i8255_get(ppi, offset);
-}
-
-static int idi_48_gpio_get_multiple(struct gpio_chip *chip, unsigned long *mask,
-	unsigned long *bits)
-{
-	struct idi_48_gpio *const idi48gpio = gpiochip_get_data(chip);
-	void __iomem *const ppi = idi48gpio->reg;
-
-	i8255_get_multiple(ppi, mask, bits, chip->ngpio);
+	*reg = base + port + port_stride;
+	*mask = BIT(line);
 
 	return 0;
 }
@@ -166,18 +123,14 @@ static const char *idi48_names[IDI48_NGPIO] = {
 
 static int idi_48_probe(struct device *dev, unsigned int id)
 {
-	struct idi_48_gpio *idi48gpio;
 	const char *const name = dev_name(dev);
+	struct gpio_regmap_config config = {};
 	void __iomem *regs;
 	struct regmap *map;
 	struct regmap_irq_chip *chip;
 	struct regmap_irq_chip_data *chip_data;
 	int err;
 
-	idi48gpio = devm_kzalloc(dev, sizeof(*idi48gpio), GFP_KERNEL);
-	if (!idi48gpio)
-		return -ENOMEM;
-
 	if (!devm_request_region(dev, base[id], IDI_48_EXTENT, name)) {
 		dev_err(dev, "Unable to lock port addresses (0x%X-0x%X)\n",
 			base[id], base[id] + IDI_48_EXTENT);
@@ -187,7 +140,6 @@ static int idi_48_probe(struct device *dev, unsigned int id)
 	regs = devm_ioport_map(dev, base[id], IDI_48_EXTENT);
 	if (!regs)
 		return -ENOMEM;
-	idi48gpio->reg = regs;
 
 	map = devm_regmap_init_mmio(dev, regs, &idi48_regmap_config);
 	if (IS_ERR(map))
@@ -211,25 +163,16 @@ static int idi_48_probe(struct device *dev, unsigned int id)
 	if (err)
 		return dev_err_probe(dev, err, "IRQ registration failed\n");
 
-	idi48gpio->chip.label = name;
-	idi48gpio->chip.parent = dev;
-	idi48gpio->chip.owner = THIS_MODULE;
-	idi48gpio->chip.base = -1;
-	idi48gpio->chip.ngpio = IDI48_NGPIO;
-	idi48gpio->chip.names = idi48_names;
-	idi48gpio->chip.get_direction = idi_48_gpio_get_direction;
-	idi48gpio->chip.direction_input = idi_48_gpio_direction_input;
-	idi48gpio->chip.get = idi_48_gpio_get;
-	idi48gpio->chip.get_multiple = idi_48_gpio_get_multiple;
-
-	err = devm_gpiochip_add_data(dev, &idi48gpio->chip, idi48gpio);
-	if (err) {
-		dev_err(dev, "GPIO registering failed (%d)\n", err);
-		return err;
-	}
+	config.parent = dev;
+	config.regmap = map;
+	config.ngpio = IDI48_NGPIO;
+	config.names = idi48_names;
+	config.reg_dat_base = GPIO_REGMAP_ADDR(0x0);
+	config.ngpio_per_reg = 8;
+	config.reg_mask_xlate = idi_48_reg_mask_xlate;
+	config.irq_domain = regmap_irq_get_domain(chip_data);
 
-	return gpiochip_irqchip_add_domain(&idi48gpio->chip,
-					   regmap_irq_get_domain(chip_data));
+	return PTR_ERR_OR_ZERO(devm_gpio_regmap_register(dev, &config));
 }
 
 static struct isa_driver idi_48_driver = {
-- 
2.38.1

[PATCH v4 6/9] gpio: i8255: Migrate to gpio-regmap API

[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.

By leveraging the gpio-regmap API, the i8255 library is reduced to
simply a devm_i8255_regmap_register() function, a configuration
structure struct i8255_regmap_config, and a helper macro
i8255_volatile_regmap_range() provided to simplify volatile PPI register
hinting for the regmap.

Legacy functions and code will be removed once all consumers have
migrated to the new i8255 library interface.

Suggested-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: William Breathitt Gray <william.gray@linaro.org>
---
 drivers/gpio/Kconfig      |   1 +
 drivers/gpio/gpio-i8255.c | 119 ++++++++++++++++++++++++++++++++++----
 drivers/gpio/gpio-i8255.h |  28 +++++++++
 3 files changed, 136 insertions(+), 12 deletions(-)

diff --git a/drivers/gpio/Kconfig b/drivers/gpio/Kconfig
index dd34039fc31b..88dfdc62992f 100644
--- a/drivers/gpio/Kconfig
+++ b/drivers/gpio/Kconfig
@@ -831,6 +831,7 @@ menu "Port-mapped I/O GPIO drivers"
 
 config GPIO_I8255
 	tristate
+	select GPIO_REGMAP
 	help
 	  Enables support for the i8255 interface library functions. The i8255
 	  interface library provides functions to facilitate communication with
diff --git a/drivers/gpio/gpio-i8255.c b/drivers/gpio/gpio-i8255.c
index 9b97db418df1..9ecb2e9b97f9 100644
--- a/drivers/gpio/gpio-i8255.c
+++ b/drivers/gpio/gpio-i8255.c
@@ -4,23 +4,31 @@
  * Copyright (C) 2022 William Breathitt Gray
  */
 #include <linux/bitmap.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-i8255.h"
 
+#define I8255_NGPIO 24
+#define I8255_NGPIO_PER_REG 8
 #define I8255_CONTROL_PORTC_LOWER_DIRECTION BIT(0)
 #define I8255_CONTROL_PORTB_DIRECTION BIT(1)
 #define I8255_CONTROL_PORTC_UPPER_DIRECTION BIT(3)
 #define I8255_CONTROL_PORTA_DIRECTION BIT(4)
 #define I8255_CONTROL_MODE_SET BIT(7)
-#define I8255_PORTA 0
-#define I8255_PORTB 1
-#define I8255_PORTC 2
+#define I8255_PORTA 0x0
+#define I8255_PORTB 0x1
+#define I8255_PORTC 0x2
+#define I8255_CONTROL 0x3
+#define I8255_REG_DAT_BASE I8255_PORTA
+#define I8255_REG_DIR_IN_BASE I8255_CONTROL
 
 static int i8255_get_port(struct i8255 __iomem *const ppi,
 			  const unsigned long io_port, const unsigned long mask)
@@ -31,20 +39,19 @@ static int i8255_get_port(struct i8255 __iomem *const ppi,
 	return ioread8(&ppi[bank].port[ppi_port]) & mask;
 }
 
-static u8 i8255_direction_mask(const unsigned long offset)
+static int i8255_direction_mask(const unsigned int offset)
 {
-	const unsigned long port_offset = offset % 8;
-	const unsigned long io_port = offset / 8;
-	const unsigned long ppi_port = io_port % 3;
+	const unsigned int stride = offset / I8255_NGPIO_PER_REG;
+	const unsigned int line = offset % I8255_NGPIO_PER_REG;
 
-	switch (ppi_port) {
+	switch (stride) {
 	case I8255_PORTA:
 		return I8255_CONTROL_PORTA_DIRECTION;
 	case I8255_PORTB:
 		return I8255_CONTROL_PORTB_DIRECTION;
 	case I8255_PORTC:
 		/* Port C can be configured by nibble */
-		if (port_offset >= 4)
+		if (line >= 4)
 			return I8255_CONTROL_PORTC_UPPER_DIRECTION;
 		return I8255_CONTROL_PORTC_LOWER_DIRECTION;
 	default:
@@ -53,6 +60,49 @@ static u8 i8255_direction_mask(const unsigned long offset)
 	}
 }
 
+static int i8255_ppi_init(struct regmap *const map, const unsigned int base)
+{
+	int err;
+
+	/* Configure all ports to MODE 0 output mode */
+	err = regmap_write(map, base + I8255_CONTROL, I8255_CONTROL_MODE_SET);
+	if (err)
+		return err;
+
+	/* Initialize all GPIO to output 0 */
+	err = regmap_write(map, base + I8255_PORTA, 0x00);
+	if (err)
+		return err;
+	err = regmap_write(map, base + I8255_PORTB, 0x00);
+	if (err)
+		return err;
+	return regmap_write(map, base + I8255_PORTC, 0x00);
+}
+
+static int i8255_reg_mask_xlate(struct gpio_regmap *gpio, unsigned int base,
+				unsigned int offset, unsigned int *reg,
+				unsigned int *mask)
+{
+	const unsigned int ppi = offset / I8255_NGPIO;
+	const unsigned int ppi_offset = offset % I8255_NGPIO;
+	const unsigned int stride = ppi_offset / I8255_NGPIO_PER_REG;
+	const unsigned int line = ppi_offset % I8255_NGPIO_PER_REG;
+
+	switch (base) {
+	case I8255_REG_DAT_BASE:
+		*reg = base + stride + ppi * 4;
+		*mask = BIT(line);
+		return 0;
+	case I8255_REG_DIR_IN_BASE:
+		*reg = base + ppi * 4;
+		*mask = i8255_direction_mask(ppi_offset);
+		return 0;
+	default:
+		/* Should never reach this path */
+		return -EINVAL;
+	}
+}
+
 static void i8255_set_port(struct i8255 __iomem *const ppi,
 			   struct i8255_state *const state,
 			   const unsigned long io_port,
@@ -93,7 +143,7 @@ void i8255_direction_input(struct i8255 __iomem *const ppi,
 	spin_lock_irqsave(&state[bank].lock, flags);
 
 	state[bank].control_state |= I8255_CONTROL_MODE_SET;
-	state[bank].control_state |= i8255_direction_mask(offset);
+	state[bank].control_state |= i8255_direction_mask(offset % 24);
 
 	iowrite8(state[bank].control_state, &ppi[bank].control);
 
@@ -125,7 +175,7 @@ void i8255_direction_output(struct i8255 __iomem *const ppi,
 	spin_lock_irqsave(&state[bank].lock, flags);
 
 	state[bank].control_state |= I8255_CONTROL_MODE_SET;
-	state[bank].control_state &= ~i8255_direction_mask(offset);
+	state[bank].control_state &= ~i8255_direction_mask(offset % 24);
 
 	iowrite8(state[bank].control_state, &ppi[bank].control);
 
@@ -165,7 +215,7 @@ int i8255_get_direction(const struct i8255_state *const state,
 	const unsigned long io_port = offset / 8;
 	const unsigned long bank = io_port / 3;
 
-	return !!(state[bank].control_state & i8255_direction_mask(offset));
+	return !!(state[bank].control_state & i8255_direction_mask(offset % 24));
 }
 EXPORT_SYMBOL_NS_GPL(i8255_get_direction, I8255);
 
@@ -282,6 +332,51 @@ void i8255_state_init(struct i8255_state *const state,
 }
 EXPORT_SYMBOL_NS_GPL(i8255_state_init, I8255);
 
+/**
+ * devm_i8255_regmap_register - Register an i8255 GPIO controller
+ * @dev:	device that is registering this i8255 GPIO device
+ * @config:	configuration for i8255_regmap_config
+ *
+ * Registers an Intel 8255 Programmable Peripheral Interface GPIO controller.
+ * Returns 0 on success and negative error number on failure.
+ */
+int devm_i8255_regmap_register(struct device *const dev,
+			       const struct i8255_regmap_config *const config)
+{
+	struct gpio_regmap_config gpio_config = {0};
+	unsigned long i;
+	int err;
+
+	if (!config->parent)
+		return -EINVAL;
+
+	if (!config->map)
+		return -EINVAL;
+
+	if (!config->num_ppi)
+		return -EINVAL;
+
+	for (i = 0; i < config->num_ppi; i++) {
+		err = i8255_ppi_init(config->map, i * 4);
+		if (err)
+			return err;
+	}
+
+	gpio_config.parent = config->parent;
+	gpio_config.regmap = config->map;
+	gpio_config.ngpio = I8255_NGPIO * config->num_ppi;
+	gpio_config.names = config->names;
+	gpio_config.reg_dat_base = GPIO_REGMAP_ADDR(I8255_REG_DAT_BASE);
+	gpio_config.reg_set_base = GPIO_REGMAP_ADDR(I8255_REG_DAT_BASE);
+	gpio_config.reg_dir_in_base = GPIO_REGMAP_ADDR(I8255_REG_DIR_IN_BASE);
+	gpio_config.ngpio_per_reg = I8255_NGPIO_PER_REG;
+	gpio_config.irq_domain = config->domain;
+	gpio_config.reg_mask_xlate = i8255_reg_mask_xlate;
+
+	return PTR_ERR_OR_ZERO(devm_gpio_regmap_register(dev, &gpio_config));
+}
+EXPORT_SYMBOL_NS_GPL(devm_i8255_regmap_register, I8255);
+
 MODULE_AUTHOR("William Breathitt Gray");
 MODULE_DESCRIPTION("Intel 8255 Programmable Peripheral Interface");
 MODULE_LICENSE("GPL");
diff --git a/drivers/gpio/gpio-i8255.h b/drivers/gpio/gpio-i8255.h
index d9084aae9446..3daa0b145890 100644
--- a/drivers/gpio/gpio-i8255.h
+++ b/drivers/gpio/gpio-i8255.h
@@ -26,6 +26,34 @@ struct i8255_state {
 	u8 control_state;
 };
 
+struct device;
+struct irq_domain;
+struct regmap;
+
+#define i8255_volatile_regmap_range(_base) regmap_reg_range(_base, _base + 0x2)
+
+/**
+ * struct i8255_regmap_config - Configuration for the register map of an i8255
+ * @parent:	parent device
+ * @map:	regmap for the i8255
+ * @num_ppi:	number of i8255 Programmable Peripheral Interface
+ * @names:	(optional) array of names for gpios
+ * @domain:	(optional) IRQ domain if the controller is interrupt-capable
+ *
+ * Note: The regmap is expected to have cache enabled and i8255 control
+ * registers not marked as volatile.
+ */
+struct i8255_regmap_config {
+	struct device *parent;
+	struct regmap *map;
+	int num_ppi;
+	const char *const *names;
+	struct irq_domain *domain;
+};
+
+int devm_i8255_regmap_register(struct device *dev,
+			       const struct i8255_regmap_config *config);
+
 void i8255_direction_input(struct i8255 __iomem *ppi, struct i8255_state *state,
 			   unsigned long offset);
 void i8255_direction_output(struct i8255 __iomem *ppi,
-- 
2.38.1

[PATCH v4 7/9] gpio: 104-dio-48e: Migrate to regmap API

[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. The 104-dio-48e module is migrated to the new
i8255 library interface leveraging the gpio-regmap API.

Suggested-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: William Breathitt Gray <william.gray@linaro.org>
---
 drivers/gpio/gpio-104-dio-48e.c | 137 ++------------------------------
 1 file changed, 7 insertions(+), 130 deletions(-)

diff --git a/drivers/gpio/gpio-104-dio-48e.c b/drivers/gpio/gpio-104-dio-48e.c
index 4c3660d5dea5..31ae98a277a4 100644
--- a/drivers/gpio/gpio-104-dio-48e.c
+++ b/drivers/gpio/gpio-104-dio-48e.c
@@ -9,7 +9,6 @@
 #include <linux/bits.h>
 #include <linux/device.h>
 #include <linux/err.h>
-#include <linux/gpio/driver.h>
 #include <linux/ioport.h>
 #include <linux/irq.h>
 #include <linux/isa.h>
@@ -42,90 +41,6 @@ MODULE_PARM_DESC(irq, "ACCES 104-DIO-48E interrupt line numbers");
 
 #define DIO48E_NUM_PPI 2
 
-/**
- * struct dio48e_reg - device register structure
- * @ppi:		Programmable Peripheral Interface groups
- */
-struct dio48e_reg {
-	struct i8255 ppi[DIO48E_NUM_PPI];
-};
-
-/**
- * struct dio48e_gpio - GPIO device private data structure
- * @chip:		instance of the gpio_chip
- * @ppi_state:		PPI device states
- * @reg:		I/O address offset for the device registers
- */
-struct dio48e_gpio {
-	struct gpio_chip chip;
-	struct i8255_state ppi_state[DIO48E_NUM_PPI];
-	struct dio48e_reg __iomem *reg;
-};
-
-static int dio48e_gpio_get_direction(struct gpio_chip *chip, unsigned int offset)
-{
-	struct dio48e_gpio *const dio48egpio = gpiochip_get_data(chip);
-
-	if (i8255_get_direction(dio48egpio->ppi_state, offset))
-		return GPIO_LINE_DIRECTION_IN;
-
-	return GPIO_LINE_DIRECTION_OUT;
-}
-
-static int dio48e_gpio_direction_input(struct gpio_chip *chip, unsigned int offset)
-{
-	struct dio48e_gpio *const dio48egpio = gpiochip_get_data(chip);
-
-	i8255_direction_input(dio48egpio->reg->ppi, dio48egpio->ppi_state,
-			      offset);
-
-	return 0;
-}
-
-static int dio48e_gpio_direction_output(struct gpio_chip *chip, unsigned int offset,
-					int value)
-{
-	struct dio48e_gpio *const dio48egpio = gpiochip_get_data(chip);
-
-	i8255_direction_output(dio48egpio->reg->ppi, dio48egpio->ppi_state,
-			       offset, value);
-
-	return 0;
-}
-
-static int dio48e_gpio_get(struct gpio_chip *chip, unsigned int offset)
-{
-	struct dio48e_gpio *const dio48egpio = gpiochip_get_data(chip);
-
-	return i8255_get(dio48egpio->reg->ppi, offset);
-}
-
-static int dio48e_gpio_get_multiple(struct gpio_chip *chip, unsigned long *mask,
-	unsigned long *bits)
-{
-	struct dio48e_gpio *const dio48egpio = gpiochip_get_data(chip);
-
-	i8255_get_multiple(dio48egpio->reg->ppi, mask, bits, chip->ngpio);
-
-	return 0;
-}
-
-static void dio48e_gpio_set(struct gpio_chip *chip, unsigned int offset, int value)
-{
-	struct dio48e_gpio *const dio48egpio = gpiochip_get_data(chip);
-
-	i8255_set(dio48egpio->reg->ppi, dio48egpio->ppi_state, offset, value);
-}
-
-static void dio48e_gpio_set_multiple(struct gpio_chip *chip,
-	unsigned long *mask, unsigned long *bits)
-{
-	struct dio48e_gpio *const dio48egpio = gpiochip_get_data(chip);
-
-	i8255_set_multiple(dio48egpio->reg->ppi, dio48egpio->ppi_state, mask,
-			   bits, chip->ngpio);
-}
-
 static const struct regmap_range dio48e_wr_ranges[] = {
 	regmap_reg_range(0x0, 0x9), regmap_reg_range(0xB, 0xB),
 	regmap_reg_range(0xD, 0xD), regmap_reg_range(0xF, 0xF),
@@ -240,25 +155,10 @@ static int dio48e_irq_init_hw(struct regmap *const map)
 	return regmap_read(map, DIO48E_DISABLE_INTERRUPT, &val);
 }
 
-static void dio48e_init_ppi(struct i8255 __iomem *const ppi,
-			    struct i8255_state *const ppi_state)
-{
-	const unsigned long ngpio = 24;
-	const unsigned long mask = GENMASK(ngpio - 1, 0);
-	const unsigned long bits = 0;
-	unsigned long i;
-
-	/* Initialize all GPIO to output 0 */
-	for (i = 0; i < DIO48E_NUM_PPI; i++) {
-		i8255_mode0_output(&ppi[i]);
-		i8255_set_multiple(&ppi[i], &ppi_state[i], &mask, &bits, ngpio);
-	}
-}
-
 static int dio48e_probe(struct device *dev, unsigned int id)
 {
-	struct dio48e_gpio *dio48egpio;
 	const char *const name = dev_name(dev);
+	struct i8255_regmap_config config = {};
 	void __iomem *regs;
 	struct regmap *map;
 	int err;
@@ -266,10 +166,6 @@ static int dio48e_probe(struct device *dev, unsigned int id)
 	unsigned int irq_mask;
 	struct regmap_irq_chip_data *chip_data;
 
-	dio48egpio = devm_kzalloc(dev, sizeof(*dio48egpio), GFP_KERNEL);
-	if (!dio48egpio)
-		return -ENOMEM;
-
 	if (!devm_request_region(dev, base[id], DIO48E_EXTENT, name)) {
 		dev_err(dev, "Unable to lock port addresses (0x%X-0x%X)\n",
 			base[id], base[id] + DIO48E_EXTENT);
@@ -279,7 +175,6 @@ static int dio48e_probe(struct device *dev, unsigned int id)
 	regs = devm_ioport_map(dev, base[id], DIO48E_EXTENT);
 	if (!regs)
 		return -ENOMEM;
-	dio48egpio->reg = regs;
 
 	map = devm_regmap_init_mmio(dev, regs, &dio48e_regmap_config);
 	if (IS_ERR(map))
@@ -314,31 +209,13 @@ static int dio48e_probe(struct device *dev, unsigned int id)
 	if (err)
 		return dev_err_probe(dev, err, "IRQ registration failed\n");
 
-	dio48egpio->chip.label = name;
-	dio48egpio->chip.parent = dev;
-	dio48egpio->chip.owner = THIS_MODULE;
-	dio48egpio->chip.base = -1;
-	dio48egpio->chip.ngpio = DIO48E_NGPIO;
-	dio48egpio->chip.names = dio48e_names;
-	dio48egpio->chip.get_direction = dio48e_gpio_get_direction;
-	dio48egpio->chip.direction_input = dio48e_gpio_direction_input;
-	dio48egpio->chip.direction_output = dio48e_gpio_direction_output;
-	dio48egpio->chip.get = dio48e_gpio_get;
-	dio48egpio->chip.get_multiple = dio48e_gpio_get_multiple;
-	dio48egpio->chip.set = dio48e_gpio_set;
-	dio48egpio->chip.set_multiple = dio48e_gpio_set_multiple;
-
-	i8255_state_init(dio48egpio->ppi_state, DIO48E_NUM_PPI);
-	dio48e_init_ppi(dio48egpio->reg->ppi, dio48egpio->ppi_state);
-
-	err = devm_gpiochip_add_data(dev, &dio48egpio->chip, dio48egpio);
-	if (err) {
-		dev_err(dev, "GPIO registering failed (%d)\n", err);
-		return err;
-	}
+	config.parent = dev;
+	config.map = map;
+	config.num_ppi = DIO48E_NUM_PPI;
+	config.names = dio48e_names;
+	config.domain = regmap_irq_get_domain(chip_data);
 
-	return gpiochip_irqchip_add_domain(&dio48egpio->chip,
-					   regmap_irq_get_domain(chip_data));
+	return devm_i8255_regmap_register(dev, &config);
 }
 
 static struct isa_driver dio48e_driver = {
-- 
2.38.1

[PATCH v4 8/9] gpio: gpio-mm: Migrate to regmap API

[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. The gpio-mm module is migrated to the new i8255
library interface leveraging the gpio-regmap API.

Suggested-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: William Breathitt Gray <william.gray@linaro.org>
---
 drivers/gpio/gpio-gpio-mm.c | 154 +++++++-----------------------------
 1 file changed, 30 insertions(+), 124 deletions(-)

diff --git a/drivers/gpio/gpio-gpio-mm.c b/drivers/gpio/gpio-gpio-mm.c
index 2689671b6b01..43d823a56e59 100644
--- a/drivers/gpio/gpio-gpio-mm.c
+++ b/drivers/gpio/gpio-gpio-mm.c
@@ -8,13 +8,13 @@
  */
 #include <linux/device.h>
 #include <linux/errno.h>
-#include <linux/gpio/driver.h>
-#include <linux/io.h>
 #include <linux/ioport.h>
 #include <linux/isa.h>
 #include <linux/kernel.h>
 #include <linux/module.h>
 #include <linux/moduleparam.h>
+#include <linux/regmap.h>
+#include <linux/types.h>
 
 #include "gpio-i8255.h"
 
@@ -30,83 +30,22 @@ MODULE_PARM_DESC(base, "Diamond Systems GPIO-MM base addresses");
 
 #define GPIOMM_NUM_PPI 2
 
-/**
- * struct gpiomm_gpio - GPIO device private data structure
- * @chip:		instance of the gpio_chip
- * @ppi_state:		Programmable Peripheral Interface group states
- * @ppi:		Programmable Peripheral Interface groups
- */
-struct gpiomm_gpio {
-	struct gpio_chip chip;
-	struct i8255_state ppi_state[GPIOMM_NUM_PPI];
-	struct i8255 __iomem *ppi;
+static const struct regmap_range gpiomm_volatile_ranges[] = {
+	i8255_volatile_regmap_range(0x0), i8255_volatile_regmap_range(0x4),
+};
+static const struct regmap_access_table gpiomm_volatile_table = {
+	.yes_ranges = gpiomm_volatile_ranges,
+	.n_yes_ranges = ARRAY_SIZE(gpiomm_volatile_ranges),
+};
+static const struct regmap_config gpiomm_regmap_config = {
+	.reg_bits = 8,
+	.reg_stride = 1,
+	.val_bits = 8,
+	.io_port = true,
+	.max_register = 0x7,
+	.volatile_table = &gpiomm_volatile_table,
+	.cache_type = REGCACHE_FLAT,
 };
-
-static int gpiomm_gpio_get_direction(struct gpio_chip *chip,
-	unsigned int offset)
-{
-	struct gpiomm_gpio *const gpiommgpio = gpiochip_get_data(chip);
-
-	if (i8255_get_direction(gpiommgpio->ppi_state, offset))
-		return GPIO_LINE_DIRECTION_IN;
-
-	return GPIO_LINE_DIRECTION_OUT;
-}
-
-static int gpiomm_gpio_direction_input(struct gpio_chip *chip,
-	unsigned int offset)
-{
-	struct gpiomm_gpio *const gpiommgpio = gpiochip_get_data(chip);
-
-	i8255_direction_input(gpiommgpio->ppi, gpiommgpio->ppi_state, offset);
-
-	return 0;
-}
-
-static int gpiomm_gpio_direction_output(struct gpio_chip *chip,
-	unsigned int offset, int value)
-{
-	struct gpiomm_gpio *const gpiommgpio = gpiochip_get_data(chip);
-
-	i8255_direction_output(gpiommgpio->ppi, gpiommgpio->ppi_state, offset,
-			       value);
-
-	return 0;
-}
-
-static int gpiomm_gpio_get(struct gpio_chip *chip, unsigned int offset)
-{
-	struct gpiomm_gpio *const gpiommgpio = gpiochip_get_data(chip);
-
-	return i8255_get(gpiommgpio->ppi, offset);
-}
-
-static int gpiomm_gpio_get_multiple(struct gpio_chip *chip, unsigned long *mask,
-	unsigned long *bits)
-{
-	struct gpiomm_gpio *const gpiommgpio = gpiochip_get_data(chip);
-
-	i8255_get_multiple(gpiommgpio->ppi, mask, bits, chip->ngpio);
-
-	return 0;
-}
-
-static void gpiomm_gpio_set(struct gpio_chip *chip, unsigned int offset,
-	int value)
-{
-	struct gpiomm_gpio *const gpiommgpio = gpiochip_get_data(chip);
-
-	i8255_set(gpiommgpio->ppi, gpiommgpio->ppi_state, offset, value);
-}
-
-static void gpiomm_gpio_set_multiple(struct gpio_chip *chip,
-	unsigned long *mask, unsigned long *bits)
-{
-	struct gpiomm_gpio *const gpiommgpio = gpiochip_get_data(chip);
-
-	i8255_set_multiple(gpiommgpio->ppi, gpiommgpio->ppi_state, mask, bits,
-			   chip->ngpio);
-}
 
 #define GPIOMM_NGPIO 48
 static const char *gpiomm_names[GPIOMM_NGPIO] = {
@@ -120,30 +59,11 @@ static const char *gpiomm_names[GPIOMM_NGPIO] = {
 	"Port 2C2", "Port 2C3", "Port 2C4", "Port 2C5", "Port 2C6", "Port 2C7",
 };
 
-static void gpiomm_init_dio(struct i8255 __iomem *const ppi,
-			    struct i8255_state *const ppi_state)
-{
-	const unsigned long ngpio = 24;
-	const unsigned long mask = GENMASK(ngpio - 1, 0);
-	const unsigned long bits = 0;
-	unsigned long i;
-
-	/* Initialize all GPIO to output 0 */
-	for (i = 0; i < GPIOMM_NUM_PPI; i++) {
-		i8255_mode0_output(&ppi[i]);
-		i8255_set_multiple(&ppi[i], &ppi_state[i], &mask, &bits, ngpio);
-	}
-}
-
 static int gpiomm_probe(struct device *dev, unsigned int id)
 {
-	struct gpiomm_gpio *gpiommgpio;
 	const char *const name = dev_name(dev);
-	int err;
-
-	gpiommgpio = devm_kzalloc(dev, sizeof(*gpiommgpio), GFP_KERNEL);
-	if (!gpiommgpio)
-		return -ENOMEM;
+	struct i8255_regmap_config config = {};
+	void __iomem *regs;
 
 	if (!devm_request_region(dev, base[id], GPIOMM_EXTENT, name)) {
 		dev_err(dev, "Unable to lock port addresses (0x%X-0x%X)\n",
@@ -151,34 +71,20 @@ static int gpiomm_probe(struct device *dev, unsigned int id)
 		return -EBUSY;
 	}
 
-	gpiommgpio->ppi = devm_ioport_map(dev, base[id], GPIOMM_EXTENT);
-	if (!gpiommgpio->ppi)
+	regs = devm_ioport_map(dev, base[id], GPIOMM_EXTENT);
+	if (!regs)
 		return -ENOMEM;
 
-	gpiommgpio->chip.label = name;
-	gpiommgpio->chip.parent = dev;
-	gpiommgpio->chip.owner = THIS_MODULE;
-	gpiommgpio->chip.base = -1;
-	gpiommgpio->chip.ngpio = GPIOMM_NGPIO;
-	gpiommgpio->chip.names = gpiomm_names;
-	gpiommgpio->chip.get_direction = gpiomm_gpio_get_direction;
-	gpiommgpio->chip.direction_input = gpiomm_gpio_direction_input;
-	gpiommgpio->chip.direction_output = gpiomm_gpio_direction_output;
-	gpiommgpio->chip.get = gpiomm_gpio_get;
-	gpiommgpio->chip.get_multiple = gpiomm_gpio_get_multiple;
-	gpiommgpio->chip.set = gpiomm_gpio_set;
-	gpiommgpio->chip.set_multiple = gpiomm_gpio_set_multiple;
-
-	i8255_state_init(gpiommgpio->ppi_state, GPIOMM_NUM_PPI);
-	gpiomm_init_dio(gpiommgpio->ppi, gpiommgpio->ppi_state);
-
-	err = devm_gpiochip_add_data(dev, &gpiommgpio->chip, gpiommgpio);
-	if (err) {
-		dev_err(dev, "GPIO registering failed (%d)\n", err);
-		return err;
-	}
+	config.map = devm_regmap_init_mmio(dev, regs, &gpiomm_regmap_config);
+	if (IS_ERR(config.map))
+		return dev_err_probe(dev, PTR_ERR(config.map),
+				     "Unable to initialize register map\n");
+
+	config.parent = dev;
+	config.num_ppi = GPIOMM_NUM_PPI;
+	config.names = gpiomm_names;
 
-	return 0;
+	return devm_i8255_regmap_register(dev, &config);
 }
 
 static struct isa_driver gpiomm_driver = {
-- 
2.38.1

[PATCH v4 9/9] gpio: i8255: Remove unused legacy interface

[William Breathitt Gray]

All i8255 library consumers have migrated to the new interface
leveraging the gpio-regmap API. Legacy interface functions and code are
removed as no longer needed.

Suggested-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: William Breathitt Gray <william.gray@linaro.org>
---
 drivers/gpio/gpio-i8255.c | 243 +-------------------------------------
 drivers/gpio/gpio-i8255.h |  40 -------
 2 files changed, 1 insertion(+), 282 deletions(-)

diff --git a/drivers/gpio/gpio-i8255.c b/drivers/gpio/gpio-i8255.c
index 9ecb2e9b97f9..64ab80fc4a1e 100644
--- a/drivers/gpio/gpio-i8255.c
+++ b/drivers/gpio/gpio-i8255.c
@@ -3,16 +3,13 @@
  * Intel 8255 Programmable Peripheral Interface
  * 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-i8255.h"
 
@@ -30,15 +27,6 @@
 #define I8255_REG_DAT_BASE I8255_PORTA
 #define I8255_REG_DIR_IN_BASE I8255_CONTROL
 
-static int i8255_get_port(struct i8255 __iomem *const ppi,
-			  const unsigned long io_port, const unsigned long mask)
-{
-	const unsigned long bank = io_port / 3;
-	const unsigned long ppi_port = io_port % 3;
-
-	return ioread8(&ppi[bank].port[ppi_port]) & mask;
-}
-
 static int i8255_direction_mask(const unsigned int offset)
 {
 	const unsigned int stride = offset / I8255_NGPIO_PER_REG;
@@ -103,235 +91,6 @@ static int i8255_reg_mask_xlate(struct gpio_regmap *gpio, unsigned int base,
 	}
 }
 
-static void i8255_set_port(struct i8255 __iomem *const ppi,
-			   struct i8255_state *const state,
-			   const unsigned long io_port,
-			   const unsigned long mask, const unsigned long bits)
-{
-	const unsigned long bank = io_port / 3;
-	const unsigned long ppi_port = io_port % 3;
-	unsigned long flags;
-	unsigned long out_state;
-
-	spin_lock_irqsave(&state[bank].lock, flags);
-
-	out_state = ioread8(&ppi[bank].port[ppi_port]);
-	out_state = (out_state & ~mask) | (bits & mask);
-	iowrite8(out_state, &ppi[bank].port[ppi_port]);
-
-	spin_unlock_irqrestore(&state[bank].lock, flags);
-}
-
-/**
- * i8255_direction_input - configure signal offset as input
- * @ppi:	Intel 8255 Programmable Peripheral Interface banks
- * @state:	devices states of the respective PPI banks
- * @offset:	signal offset to configure as input
- *
- * Configures a signal @offset as input for the respective Intel 8255
- * Programmable Peripheral Interface (@ppi) banks. The @state control_state
- * values are updated to reflect the new configuration.
- */
-void i8255_direction_input(struct i8255 __iomem *const ppi,
-			   struct i8255_state *const state,
-			   const unsigned long offset)
-{
-	const unsigned long io_port = offset / 8;
-	const unsigned long bank = io_port / 3;
-	unsigned long flags;
-
-	spin_lock_irqsave(&state[bank].lock, flags);
-
-	state[bank].control_state |= I8255_CONTROL_MODE_SET;
-	state[bank].control_state |= i8255_direction_mask(offset % 24);
-
-	iowrite8(state[bank].control_state, &ppi[bank].control);
-
-	spin_unlock_irqrestore(&state[bank].lock, flags);
-}
-EXPORT_SYMBOL_NS_GPL(i8255_direction_input, I8255);
-
-/**
- * i8255_direction_output - configure signal offset as output
- * @ppi:	Intel 8255 Programmable Peripheral Interface banks
- * @state:	devices states of the respective PPI banks
- * @offset:	signal offset to configure as output
- * @value:	signal value to output
- *
- * Configures a signal @offset as output for the respective Intel 8255
- * Programmable Peripheral Interface (@ppi) banks and sets the respective signal
- * output to the desired @value. The @state control_state values are updated to
- * reflect the new configuration.
- */
-void i8255_direction_output(struct i8255 __iomem *const ppi,
-			    struct i8255_state *const state,
-			    const unsigned long offset,
-			    const unsigned long value)
-{
-	const unsigned long io_port = offset / 8;
-	const unsigned long bank = io_port / 3;
-	unsigned long flags;
-
-	spin_lock_irqsave(&state[bank].lock, flags);
-
-	state[bank].control_state |= I8255_CONTROL_MODE_SET;
-	state[bank].control_state &= ~i8255_direction_mask(offset % 24);
-
-	iowrite8(state[bank].control_state, &ppi[bank].control);
-
-	spin_unlock_irqrestore(&state[bank].lock, flags);
-
-	i8255_set(ppi, state, offset, value);
-}
-EXPORT_SYMBOL_NS_GPL(i8255_direction_output, I8255);
-
-/**
- * i8255_get - get signal value at signal offset
- * @ppi:	Intel 8255 Programmable Peripheral Interface banks
- * @offset:	offset of signal to get
- *
- * Returns the signal value (0=low, 1=high) for the signal at @offset for the
- * respective Intel 8255 Programmable Peripheral Interface (@ppi) banks.
- */
-int i8255_get(struct i8255 __iomem *const ppi, const unsigned long offset)
-{
-	const unsigned long io_port = offset / 8;
-	const unsigned long offset_mask = BIT(offset % 8);
-
-	return !!i8255_get_port(ppi, io_port, offset_mask);
-}
-EXPORT_SYMBOL_NS_GPL(i8255_get, I8255);
-
-/**
- * i8255_get_direction - get the I/O direction for a signal offset
- * @state:	devices states of the respective PPI banks
- * @offset:	offset of signal to get direction
- *
- * Returns the signal direction (0=output, 1=input) for the signal at @offset.
- */
-int i8255_get_direction(const struct i8255_state *const state,
-			const unsigned long offset)
-{
-	const unsigned long io_port = offset / 8;
-	const unsigned long bank = io_port / 3;
-
-	return !!(state[bank].control_state & i8255_direction_mask(offset % 24));
-}
-EXPORT_SYMBOL_NS_GPL(i8255_get_direction, I8255);
-
-/**
- * i8255_get_multiple - get multiple signal values at multiple signal offsets
- * @ppi:	Intel 8255 Programmable Peripheral Interface banks
- * @mask:	mask of signals to get
- * @bits:	bitmap to store signal values
- * @ngpio:	number of GPIO signals of the respective PPI banks
- *
- * Stores in @bits the values (0=low, 1=high) for the signals defined by @mask
- * for the respective Intel 8255 Programmable Peripheral Interface (@ppi) banks.
- */
-void i8255_get_multiple(struct i8255 __iomem *const ppi,
-			const unsigned long *const mask,
-			unsigned long *const bits, const unsigned long ngpio)
-{
-	unsigned long offset;
-	unsigned long port_mask;
-	unsigned long io_port;
-	unsigned long port_state;
-
-	bitmap_zero(bits, ngpio);
-
-	for_each_set_clump8(offset, port_mask, mask, ngpio) {
-		io_port = offset / 8;
-		port_state = i8255_get_port(ppi, io_port, port_mask);
-
-		bitmap_set_value8(bits, port_state, offset);
-	}
-}
-EXPORT_SYMBOL_NS_GPL(i8255_get_multiple, I8255);
-
-/**
- * i8255_mode0_output - configure all PPI ports to MODE 0 output mode
- * @ppi:	Intel 8255 Programmable Peripheral Interface bank
- *
- * Configures all Intel 8255 Programmable Peripheral Interface (@ppi) ports to
- * MODE 0 (Basic Input/Output) output mode.
- */
-void i8255_mode0_output(struct i8255 __iomem *const ppi)
-{
-	iowrite8(I8255_CONTROL_MODE_SET, &ppi->control);
-}
-EXPORT_SYMBOL_NS_GPL(i8255_mode0_output, I8255);
-
-/**
- * i8255_set - set signal value at signal offset
- * @ppi:	Intel 8255 Programmable Peripheral Interface banks
- * @state:	devices states of the respective PPI banks
- * @offset:	offset of signal to set
- * @value:	value of signal to set
- *
- * Assigns output @value for the signal at @offset for the respective Intel 8255
- * Programmable Peripheral Interface (@ppi) banks.
- */
-void i8255_set(struct i8255 __iomem *const ppi, struct i8255_state *const state,
-	       const unsigned long offset, const unsigned long value)
-{
-	const unsigned long io_port = offset / 8;
-	const unsigned long port_offset = offset % 8;
-	const unsigned long mask = BIT(port_offset);
-	const unsigned long bits = value << port_offset;
-
-	i8255_set_port(ppi, state, io_port, mask, bits);
-}
-EXPORT_SYMBOL_NS_GPL(i8255_set, I8255);
-
-/**
- * i8255_set_multiple - set signal values at multiple signal offsets
- * @ppi:	Intel 8255 Programmable Peripheral Interface banks
- * @state:	devices states of the respective PPI banks
- * @mask:	mask of signals to set
- * @bits:	bitmap of signal output values
- * @ngpio:	number of GPIO signals of the respective PPI banks
- *
- * Assigns output values defined by @bits for the signals defined by @mask for
- * the respective Intel 8255 Programmable Peripheral Interface (@ppi) banks.
- */
-void i8255_set_multiple(struct i8255 __iomem *const ppi,
-			struct i8255_state *const state,
-			const unsigned long *const mask,
-			const unsigned long *const bits,
-			const unsigned long ngpio)
-{
-	unsigned long offset;
-	unsigned long port_mask;
-	unsigned long io_port;
-	unsigned long value;
-
-	for_each_set_clump8(offset, port_mask, mask, ngpio) {
-		io_port = offset / 8;
-		value = bitmap_get_value8(bits, offset);
-		i8255_set_port(ppi, state, io_port, port_mask, value);
-	}
-}
-EXPORT_SYMBOL_NS_GPL(i8255_set_multiple, I8255);
-
-/**
- * i8255_state_init - initialize i8255_state structure
- * @state:	devices states of the respective PPI banks
- * @nbanks:	number of Intel 8255 Programmable Peripheral Interface banks
- *
- * Initializes the @state of each Intel 8255 Programmable Peripheral Interface
- * bank for use in i8255 library functions.
- */
-void i8255_state_init(struct i8255_state *const state,
-		      const unsigned long nbanks)
-{
-	unsigned long bank;
-
-	for (bank = 0; bank < nbanks; bank++)
-		spin_lock_init(&state[bank].lock);
-}
-EXPORT_SYMBOL_NS_GPL(i8255_state_init, I8255);
-
 /**
  * devm_i8255_regmap_register - Register an i8255 GPIO controller
  * @dev:	device that is registering this i8255 GPIO device
diff --git a/drivers/gpio/gpio-i8255.h b/drivers/gpio/gpio-i8255.h
index 3daa0b145890..9dcf639b94df 100644
--- a/drivers/gpio/gpio-i8255.h
+++ b/drivers/gpio/gpio-i8255.h
@@ -3,29 +3,6 @@
 #ifndef _I8255_H_
 #define _I8255_H_
 
-#include <linux/spinlock.h>
-#include <linux/types.h>
-
-/**
- * struct i8255 - Intel 8255 register structure
- * @port:	Port A, B, and C
- * @control:	Control register
- */
-struct i8255 {
-	u8 port[3];
-	u8 control;
-};
-
-/**
- * struct i8255_state - Intel 8255 state structure
- * @lock:		synchronization lock for accessing device state
- * @control_state:	Control register state
- */
-struct i8255_state {
-	spinlock_t lock;
-	u8 control_state;
-};
-
 struct device;
 struct irq_domain;
 struct regmap;
@@ -54,21 +31,4 @@ struct i8255_regmap_config {
 int devm_i8255_regmap_register(struct device *dev,
 			       const struct i8255_regmap_config *config);
 
-void i8255_direction_input(struct i8255 __iomem *ppi, struct i8255_state *state,
-			   unsigned long offset);
-void i8255_direction_output(struct i8255 __iomem *ppi,
-			    struct i8255_state *state, unsigned long offset,
-			    unsigned long value);
-int i8255_get(struct i8255 __iomem *ppi, unsigned long offset);
-int i8255_get_direction(const struct i8255_state *state, unsigned long offset);
-void i8255_get_multiple(struct i8255 __iomem *ppi, const unsigned long *mask,
-			unsigned long *bits, unsigned long ngpio);
-void i8255_mode0_output(struct i8255 __iomem *const ppi);
-void i8255_set(struct i8255 __iomem *ppi, struct i8255_state *state,
-	       unsigned long offset, unsigned long value);
-void i8255_set_multiple(struct i8255 __iomem *ppi, struct i8255_state *state,
-			const unsigned long *mask, const unsigned long *bits,
-			unsigned long ngpio);
-void i8255_state_init(struct i8255_state *const state, unsigned long nbanks);
-
 #endif /* _I8255_H_ */
-- 
2.38.1

Re: [PATCH v4 3/9] gpio: 104-dio-48e: Migrate to the regmap-irq API

[Andy Shevchenko]

On Fri, Dec 02, 2022 at 11:27:09AM -0500, William Breathitt Gray wrote:
> 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.
> 
> For the 104-dio-48e we have the following IRQ registers (0xB and 0xF):
> 
>     Base Address +B (Write): Enable Interrupt
>     Base Address +B (Read): Disable Interrupt
>     Base Address +F (Read/Write): Clear Interrupt
> 
> Any write to 0xB will enable interrupts, while any read will disable
> interrupts. Interrupts are cleared by a read or any write to 0xF.
> There's no IRQ status register, so software has to assume that if an
> interrupt is raised then it was for the 104-DIO-48E device.

Assuming the regmap IRQ changes are accepted,
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>

Also a nit-pick below.

> Signed-off-by: William Breathitt Gray <william.gray@linaro.org>
> ---
>  drivers/gpio/Kconfig            |   1 +
>  drivers/gpio/gpio-104-dio-48e.c | 268 +++++++++++++++-----------------
>  2 files changed, 127 insertions(+), 142 deletions(-)
> 
> diff --git a/drivers/gpio/Kconfig b/drivers/gpio/Kconfig
> index ec7cfd4f52b1..b62bef4e563d 100644
> --- a/drivers/gpio/Kconfig
> +++ b/drivers/gpio/Kconfig
> @@ -845,6 +845,7 @@ config GPIO_104_DIO_48E
>  	tristate "ACCES 104-DIO-48E GPIO support"
>  	depends on PC104
>  	select ISA_BUS_API
> +	select REGMAP_IRQ
>  	select GPIOLIB_IRQCHIP
>  	select GPIO_I8255
>  	help
> diff --git a/drivers/gpio/gpio-104-dio-48e.c b/drivers/gpio/gpio-104-dio-48e.c
> index 7b8829c8e423..4c3660d5dea5 100644
> --- a/drivers/gpio/gpio-104-dio-48e.c
> +++ b/drivers/gpio/gpio-104-dio-48e.c
> @@ -8,17 +8,15 @@
>   */
>  #include <linux/bits.h>
>  #include <linux/device.h>
> -#include <linux/errno.h>
> +#include <linux/err.h>
>  #include <linux/gpio/driver.h>
> -#include <linux/io.h>
>  #include <linux/ioport.h>
> -#include <linux/interrupt.h>
> -#include <linux/irqdesc.h>
> +#include <linux/irq.h>
>  #include <linux/isa.h>
>  #include <linux/kernel.h>
>  #include <linux/module.h>
>  #include <linux/moduleparam.h>
> -#include <linux/spinlock.h>
> +#include <linux/regmap.h>
>  #include <linux/types.h>
>  
>  #include "gpio-i8255.h"
> @@ -38,46 +36,30 @@ static unsigned int num_irq;
>  module_param_hw_array(irq, uint, irq, &num_irq, 0);
>  MODULE_PARM_DESC(irq, "ACCES 104-DIO-48E interrupt line numbers");
>  
> +#define DIO48E_ENABLE_INTERRUPT 0xB
> +#define DIO48E_DISABLE_INTERRUPT DIO48E_ENABLE_INTERRUPT
> +#define DIO48E_CLEAR_INTERRUPT 0xF
> +
>  #define DIO48E_NUM_PPI 2
>  
>  /**
>   * struct dio48e_reg - device register structure
>   * @ppi:		Programmable Peripheral Interface groups
> - * @enable_buffer:	Enable/Disable Buffer groups
> - * @unused1:		Unused
> - * @enable_interrupt:	Write: Enable Interrupt
> - *			Read: Disable Interrupt
> - * @unused2:		Unused
> - * @enable_counter:	Write: Enable Counter/Timer Addressing
> - *			Read: Disable Counter/Timer Addressing
> - * @unused3:		Unused
> - * @clear_interrupt:	Clear Interrupt
>   */
>  struct dio48e_reg {
>  	struct i8255 ppi[DIO48E_NUM_PPI];
> -	u8 enable_buffer[DIO48E_NUM_PPI];
> -	u8 unused1;
> -	u8 enable_interrupt;
> -	u8 unused2;
> -	u8 enable_counter;
> -	u8 unused3;
> -	u8 clear_interrupt;
>  };
>  
>  /**
>   * struct dio48e_gpio - GPIO device private data structure
>   * @chip:		instance of the gpio_chip
>   * @ppi_state:		PPI device states
> - * @lock:		synchronization lock to prevent I/O race conditions
>   * @reg:		I/O address offset for the device registers
> - * @irq_mask:		I/O bits affected by interrupts
>   */
>  struct dio48e_gpio {
>  	struct gpio_chip chip;
>  	struct i8255_state ppi_state[DIO48E_NUM_PPI];
> -	raw_spinlock_t lock;
>  	struct dio48e_reg __iomem *reg;
> -	unsigned char irq_mask;
>  };
>  
>  static int dio48e_gpio_get_direction(struct gpio_chip *chip, unsigned int offset)
> @@ -144,106 +126,90 @@ static void dio48e_gpio_set_multiple(struct gpio_chip *chip,
>  			   bits, chip->ngpio);
>  }
>  
> -static void dio48e_irq_ack(struct irq_data *data)
> -{
> -}
> -
> -static void dio48e_irq_mask(struct irq_data *data)
> -{
> -	struct gpio_chip *chip = irq_data_get_irq_chip_data(data);
> -	struct dio48e_gpio *const dio48egpio = gpiochip_get_data(chip);
> -	const unsigned long offset = irqd_to_hwirq(data);
> -	unsigned long flags;
> -
> -	/* only bit 3 on each respective Port C supports interrupts */
> -	if (offset != 19 && offset != 43)
> -		return;
> -
> -	raw_spin_lock_irqsave(&dio48egpio->lock, flags);
> -
> -	if (offset == 19)
> -		dio48egpio->irq_mask &= ~BIT(0);
> -	else
> -		dio48egpio->irq_mask &= ~BIT(1);
> -	gpiochip_disable_irq(chip, offset);
> -
> -	if (!dio48egpio->irq_mask)
> -		/* disable interrupts */
> -		ioread8(&dio48egpio->reg->enable_interrupt);
> -
> -	raw_spin_unlock_irqrestore(&dio48egpio->lock, flags);
> -}
> -
> -static void dio48e_irq_unmask(struct irq_data *data)
> -{
> -	struct gpio_chip *chip = irq_data_get_irq_chip_data(data);
> -	struct dio48e_gpio *const dio48egpio = gpiochip_get_data(chip);
> -	const unsigned long offset = irqd_to_hwirq(data);
> -	unsigned long flags;
> -
> -	/* only bit 3 on each respective Port C supports interrupts */
> -	if (offset != 19 && offset != 43)
> -		return;
> -
> -	raw_spin_lock_irqsave(&dio48egpio->lock, flags);
> +static const struct regmap_range dio48e_wr_ranges[] = {
> +	regmap_reg_range(0x0, 0x9), regmap_reg_range(0xB, 0xB),
> +	regmap_reg_range(0xD, 0xD), regmap_reg_range(0xF, 0xF),
> +};
> +static const struct regmap_range dio48e_rd_ranges[] = {
> +	regmap_reg_range(0x0, 0x2), regmap_reg_range(0x4, 0x6),
> +	regmap_reg_range(0xB, 0xB), regmap_reg_range(0xD, 0xD),
> +	regmap_reg_range(0xF, 0xF),
> +};
> +static const struct regmap_range dio48e_volatile_ranges[] = {
> +	i8255_volatile_regmap_range(0x0), i8255_volatile_regmap_range(0x4),
> +	regmap_reg_range(0xB, 0xB), regmap_reg_range(0xD, 0xD),
> +	regmap_reg_range(0xF, 0xF),
> +};
> +static const struct regmap_range dio48e_precious_ranges[] = {
> +	regmap_reg_range(0xB, 0xB), regmap_reg_range(0xD, 0xD),
> +	regmap_reg_range(0xF, 0xF),
> +};
> +static const struct regmap_access_table dio48e_wr_table = {
> +	.yes_ranges = dio48e_wr_ranges,
> +	.n_yes_ranges = ARRAY_SIZE(dio48e_wr_ranges),
> +};
> +static const struct regmap_access_table dio48e_rd_table = {
> +	.yes_ranges = dio48e_rd_ranges,
> +	.n_yes_ranges = ARRAY_SIZE(dio48e_rd_ranges),
> +};
> +static const struct regmap_access_table dio48e_volatile_table = {
> +	.yes_ranges = dio48e_volatile_ranges,
> +	.n_yes_ranges = ARRAY_SIZE(dio48e_volatile_ranges),
> +};
> +static const struct regmap_access_table dio48e_precious_table = {
> +	.yes_ranges = dio48e_precious_ranges,
> +	.n_yes_ranges = ARRAY_SIZE(dio48e_precious_ranges),
> +};
> +static const struct regmap_config dio48e_regmap_config = {
> +	.reg_bits = 8,
> +	.reg_stride = 1,
> +	.val_bits = 8,
> +	.io_port = true,
> +	.max_register = 0xF,
> +	.wr_table = &dio48e_wr_table,
> +	.rd_table = &dio48e_rd_table,
> +	.volatile_table = &dio48e_volatile_table,
> +	.precious_table = &dio48e_precious_table,
> +	.cache_type = REGCACHE_FLAT,
> +};
>  
> -	if (!dio48egpio->irq_mask) {
> -		/* enable interrupts */
> -		iowrite8(0x00, &dio48egpio->reg->clear_interrupt);
> -		iowrite8(0x00, &dio48egpio->reg->enable_interrupt);
> +/* only bit 3 on each respective Port C supports interrupts */
> +#define DIO48E_REGMAP_IRQ(_ppi)						\
> +	[19 + (_ppi) * 24] = {						\
> +		.mask = BIT(_ppi),					\
> +		.type = { .types_supported = IRQ_TYPE_EDGE_RISING },	\
>  	}
>  
> -	gpiochip_enable_irq(chip, offset);
> -	if (offset == 19)
> -		dio48egpio->irq_mask |= BIT(0);
> -	else
> -		dio48egpio->irq_mask |= BIT(1);
> -
> -	raw_spin_unlock_irqrestore(&dio48egpio->lock, flags);
> -}
> -
> -static int dio48e_irq_set_type(struct irq_data *data, unsigned int flow_type)
> -{
> -	const unsigned long offset = irqd_to_hwirq(data);
> -
> -	/* only bit 3 on each respective Port C supports interrupts */
> -	if (offset != 19 && offset != 43)
> -		return -EINVAL;
> -
> -	if (flow_type != IRQ_TYPE_NONE && flow_type != IRQ_TYPE_EDGE_RISING)
> -		return -EINVAL;
> -
> -	return 0;
> -}
> -
> -static const struct irq_chip dio48e_irqchip = {
> -	.name = "104-dio-48e",
> -	.irq_ack = dio48e_irq_ack,
> -	.irq_mask = dio48e_irq_mask,
> -	.irq_unmask = dio48e_irq_unmask,
> -	.irq_set_type = dio48e_irq_set_type,
> -	.flags = IRQCHIP_IMMUTABLE,
> -	GPIOCHIP_IRQ_RESOURCE_HELPERS,
> +static const struct regmap_irq dio48e_regmap_irqs[] = {
> +	DIO48E_REGMAP_IRQ(0), DIO48E_REGMAP_IRQ(1),
>  };
>  
> -static irqreturn_t dio48e_irq_handler(int irq, void *dev_id)
> +static int dio48e_handle_mask_sync(struct regmap *const map, const int index,
> +				   const unsigned int mask_buf_def,
> +				   const unsigned int mask_buf,
> +				   void *const irq_drv_data)
>  {
> -	struct dio48e_gpio *const dio48egpio = dev_id;
> -	struct gpio_chip *const chip = &dio48egpio->chip;
> -	const unsigned long irq_mask = dio48egpio->irq_mask;
> -	unsigned long gpio;
> +	unsigned int *const irq_mask = irq_drv_data;
> +	const unsigned int prev_mask = *irq_mask;

> +	const unsigned int all_masked = 0x3;

Perhaps GENMASK(1, 0) ?

> +	unsigned int val;
>  
> -	for_each_set_bit(gpio, &irq_mask, 2)
> -		generic_handle_domain_irq(chip->irq.domain,
> -					  19 + gpio*24);
> +	/* exit early if no change since the previous mask */
> +	if (mask_buf == prev_mask)
> +		return 0;
>  
> -	raw_spin_lock(&dio48egpio->lock);
> +	/* remember the current mask for the next mask sync */
> +	*irq_mask = mask_buf;
>  
> -	iowrite8(0x00, &dio48egpio->reg->clear_interrupt);
> +	/* if all previously masked, enable interrupts when unmasking */
> +	if (prev_mask == all_masked)
> +		return regmap_write(map, DIO48E_ENABLE_INTERRUPT, 0x00);
>  
> -	raw_spin_unlock(&dio48egpio->lock);
> +	/* if all are currently masked, disable interrupts */
> +	if (mask_buf == all_masked)
> +		return regmap_read(map, DIO48E_DISABLE_INTERRUPT, &val);
>  
> -	return IRQ_HANDLED;
> +	return 0;
>  }
>  
>  #define DIO48E_NGPIO 48
> @@ -266,14 +232,12 @@ static const char *dio48e_names[DIO48E_NGPIO] = {
>  	"PPI Group 1 Port C 5", "PPI Group 1 Port C 6", "PPI Group 1 Port C 7"
>  };
>  
> -static int dio48e_irq_init_hw(struct gpio_chip *gc)
> +static int dio48e_irq_init_hw(struct regmap *const map)
>  {
> -	struct dio48e_gpio *const dio48egpio = gpiochip_get_data(gc);
> +	unsigned int val;
>  
>  	/* Disable IRQ by default */
> -	ioread8(&dio48egpio->reg->enable_interrupt);
> -
> -	return 0;
> +	return regmap_read(map, DIO48E_DISABLE_INTERRUPT, &val);
>  }
>  
>  static void dio48e_init_ppi(struct i8255 __iomem *const ppi,
> @@ -295,8 +259,12 @@ static int dio48e_probe(struct device *dev, unsigned int id)
>  {
>  	struct dio48e_gpio *dio48egpio;
>  	const char *const name = dev_name(dev);
> -	struct gpio_irq_chip *girq;
> +	void __iomem *regs;
> +	struct regmap *map;
>  	int err;
> +	struct regmap_irq_chip *chip;
> +	unsigned int irq_mask;
> +	struct regmap_irq_chip_data *chip_data;
>  
>  	dio48egpio = devm_kzalloc(dev, sizeof(*dio48egpio), GFP_KERNEL);
>  	if (!dio48egpio)
> @@ -308,9 +276,43 @@ static int dio48e_probe(struct device *dev, unsigned int id)
>  		return -EBUSY;
>  	}
>  
> -	dio48egpio->reg = devm_ioport_map(dev, base[id], DIO48E_EXTENT);
> -	if (!dio48egpio->reg)
> +	regs = devm_ioport_map(dev, base[id], DIO48E_EXTENT);
> +	if (!regs)
>  		return -ENOMEM;
> +	dio48egpio->reg = regs;
> +
> +	map = devm_regmap_init_mmio(dev, regs, &dio48e_regmap_config);
> +	if (IS_ERR(map))
> +		return dev_err_probe(dev, PTR_ERR(map),
> +				     "Unable to initialize register map\n");
> +
> +	chip = devm_kzalloc(dev, sizeof(*chip), GFP_KERNEL);
> +	if (!chip)
> +		return -ENOMEM;
> +
> +	chip->irq_drv_data = devm_kzalloc(dev, sizeof(irq_mask), GFP_KERNEL);
> +	if (!chip->irq_drv_data)
> +		return -ENOMEM;
> +
> +	chip->name = name;
> +	/* No IRQ status register so use CLEAR_INTERRUPT register instead */
> +	chip->status_base = DIO48E_CLEAR_INTERRUPT;
> +	chip->mask_base = DIO48E_ENABLE_INTERRUPT;
> +	chip->clear_on_unmask = true;
> +	chip->status_invert = true;
> +	chip->num_regs = 1;
> +	chip->irqs = dio48e_regmap_irqs;
> +	chip->num_irqs = ARRAY_SIZE(dio48e_regmap_irqs);
> +	chip->handle_mask_sync = dio48e_handle_mask_sync;
> +
> +	/* Initialize to prevent spurious interrupts before we're ready */
> +	err = dio48e_irq_init_hw(map);
> +	if (err)
> +		return err;
> +
> +	err = devm_regmap_add_irq_chip(dev, map, irq[id], 0, 0, chip, &chip_data);
> +	if (err)
> +		return dev_err_probe(dev, err, "IRQ registration failed\n");
>  
>  	dio48egpio->chip.label = name;
>  	dio48egpio->chip.parent = dev;
> @@ -326,18 +328,6 @@ static int dio48e_probe(struct device *dev, unsigned int id)
>  	dio48egpio->chip.set = dio48e_gpio_set;
>  	dio48egpio->chip.set_multiple = dio48e_gpio_set_multiple;
>  
> -	girq = &dio48egpio->chip.irq;
> -	gpio_irq_chip_set_chip(girq, &dio48e_irqchip);
> -	/* This will let us handle the parent IRQ in the driver */
> -	girq->parent_handler = NULL;
> -	girq->num_parents = 0;
> -	girq->parents = NULL;
> -	girq->default_type = IRQ_TYPE_NONE;
> -	girq->handler = handle_edge_irq;
> -	girq->init_hw = dio48e_irq_init_hw;
> -
> -	raw_spin_lock_init(&dio48egpio->lock);
> -
>  	i8255_state_init(dio48egpio->ppi_state, DIO48E_NUM_PPI);
>  	dio48e_init_ppi(dio48egpio->reg->ppi, dio48egpio->ppi_state);
>  
> @@ -347,14 +337,8 @@ static int dio48e_probe(struct device *dev, unsigned int id)
>  		return err;
>  	}
>  
> -	err = devm_request_irq(dev, irq[id], dio48e_irq_handler, 0, name,
> -		dio48egpio);
> -	if (err) {
> -		dev_err(dev, "IRQ handler registering failed (%d)\n", err);
> -		return err;
> -	}
> -
> -	return 0;
> +	return gpiochip_irqchip_add_domain(&dio48egpio->chip,
> +					   regmap_irq_get_domain(chip_data));
>  }
>  
>  static struct isa_driver dio48e_driver = {
> -- 
> 2.38.1
> 

-- 
With Best Regards,
Andy Shevchenko

Re: [PATCH v4 4/9] gpio: 104-idi-48: Migrate to the regmap-irq API

[Andy Shevchenko]

On Fri, Dec 02, 2022 at 11:27:10AM -0500, William Breathitt Gray wrote:
> 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.
> 
> For the 104-idi-48, we get an IRQ register with some status information
> and basic masking, but it's broken down by banks rather than individual
> GPIO. There are six banks (8 GPIO lines each) that correspond to the
> lower six bits of the IRQ register (bits 0-5):
> 
>     Base Address + 7 (Read): IRQ Status Register/IRQ Clear
>         Bit 0-5: Respective Bank IRQ Statuses
>         Bit 6: IRQ Status (Active Low)
>         Bit 7: IRQ Enable Status
>     Base Address + 7 (Write): IRQ Enable/Disable
>         Bit 0-5: Respective Bank IRQ Enable/Disable

Assuming the regmap IRQ changes are accepted,
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>

> Signed-off-by: William Breathitt Gray <william.gray@linaro.org>
> ---
>  drivers/gpio/Kconfig           |   1 +
>  drivers/gpio/gpio-104-idi-48.c | 249 ++++++++++++---------------------
>  2 files changed, 92 insertions(+), 158 deletions(-)
> 
> diff --git a/drivers/gpio/Kconfig b/drivers/gpio/Kconfig
> index b62bef4e563d..6892979e511a 100644
> --- a/drivers/gpio/Kconfig
> +++ b/drivers/gpio/Kconfig
> @@ -871,6 +871,7 @@ config GPIO_104_IDI_48
>  	tristate "ACCES 104-IDI-48 GPIO support"
>  	depends on PC104
>  	select ISA_BUS_API
> +	select REGMAP_IRQ
>  	select GPIOLIB_IRQCHIP
>  	select GPIO_I8255
>  	help
> diff --git a/drivers/gpio/gpio-104-idi-48.c b/drivers/gpio/gpio-104-idi-48.c
> index c5e231fde1af..f936e3e0ff12 100644
> --- a/drivers/gpio/gpio-104-idi-48.c
> +++ b/drivers/gpio/gpio-104-idi-48.c
> @@ -8,17 +8,16 @@
>   */
>  #include <linux/bits.h>
>  #include <linux/device.h>
> -#include <linux/errno.h>
> +#include <linux/err.h>
>  #include <linux/gpio/driver.h>
> -#include <linux/io.h>
> -#include <linux/ioport.h>
>  #include <linux/interrupt.h>
> -#include <linux/irqdesc.h>
> +#include <linux/ioport.h>
> +#include <linux/irq.h>
>  #include <linux/isa.h>
>  #include <linux/kernel.h>
>  #include <linux/module.h>
>  #include <linux/moduleparam.h>
> -#include <linux/spinlock.h>
> +#include <linux/regmap.h>
>  #include <linux/types.h>
>  
>  #include "gpio-i8255.h"
> @@ -38,6 +37,9 @@ static unsigned int num_irq;
>  module_param_hw_array(irq, uint, irq, &num_irq, 0);
>  MODULE_PARM_DESC(irq, "ACCES 104-IDI-48 interrupt line numbers");
>  
> +#define IDI48_IRQ_STATUS 0x7
> +#define IDI48_IRQ_ENABLE IDI48_IRQ_STATUS
> +
>  /**
>   * struct idi_48_reg - device register structure
>   * @port0:	Port 0 Inputs
> @@ -56,17 +58,11 @@ struct idi_48_reg {
>  /**
>   * struct idi_48_gpio - GPIO device private data structure
>   * @chip:	instance of the gpio_chip
> - * @lock:	synchronization lock to prevent I/O race conditions
> - * @irq_mask:	input bits affected by interrupts
>   * @reg:	I/O address offset for the device registers
> - * @cos_enb:	Change-Of-State IRQ enable boundaries mask
>   */
>  struct idi_48_gpio {
>  	struct gpio_chip chip;
> -	spinlock_t lock;
> -	unsigned char irq_mask[6];
>  	struct idi_48_reg __iomem *reg;
> -	unsigned char cos_enb;
>  };
>  
>  static int idi_48_gpio_get_direction(struct gpio_chip *chip, unsigned int offset)
> @@ -98,125 +94,65 @@ static int idi_48_gpio_get_multiple(struct gpio_chip *chip, unsigned long *mask,
>  	return 0;
>  }
>  
> -static void idi_48_irq_ack(struct irq_data *data)
> -{
> -}
> -
> -static void idi_48_irq_mask(struct irq_data *data)
> -{
> -	struct gpio_chip *chip = irq_data_get_irq_chip_data(data);
> -	struct idi_48_gpio *const idi48gpio = gpiochip_get_data(chip);
> -	const unsigned int offset = irqd_to_hwirq(data);
> -	const unsigned long boundary = offset / 8;
> -	const unsigned long mask = BIT(offset % 8);
> -	unsigned long flags;
> -
> -	spin_lock_irqsave(&idi48gpio->lock, flags);
> -
> -	idi48gpio->irq_mask[boundary] &= ~mask;
> -	gpiochip_disable_irq(chip, offset);
> -
> -	/* Exit early if there are still input lines with IRQ unmasked */
> -	if (idi48gpio->irq_mask[boundary])
> -		goto exit;
> -
> -	idi48gpio->cos_enb &= ~BIT(boundary);
> -
> -	iowrite8(idi48gpio->cos_enb, &idi48gpio->reg->irq);
> -
> -exit:
> -	spin_unlock_irqrestore(&idi48gpio->lock, flags);
> -}
> -
> -static void idi_48_irq_unmask(struct irq_data *data)
> -{
> -	struct gpio_chip *chip = irq_data_get_irq_chip_data(data);
> -	struct idi_48_gpio *const idi48gpio = gpiochip_get_data(chip);
> -	const unsigned int offset = irqd_to_hwirq(data);
> -	const unsigned long boundary = offset / 8;
> -	const unsigned long mask = BIT(offset % 8);
> -	unsigned int prev_irq_mask;
> -	unsigned long flags;
> -
> -	spin_lock_irqsave(&idi48gpio->lock, flags);
> -
> -	prev_irq_mask = idi48gpio->irq_mask[boundary];
> -
> -	gpiochip_enable_irq(chip, offset);
> -	idi48gpio->irq_mask[boundary] |= mask;
> -
> -	/* Exit early if IRQ was already unmasked for this boundary */
> -	if (prev_irq_mask)
> -		goto exit;
> -
> -	idi48gpio->cos_enb |= BIT(boundary);
> -
> -	iowrite8(idi48gpio->cos_enb, &idi48gpio->reg->irq);
> -
> -exit:
> -	spin_unlock_irqrestore(&idi48gpio->lock, flags);
> -}
> -
> -static int idi_48_irq_set_type(struct irq_data *data, unsigned int flow_type)
> -{
> -	/* The only valid irq types are none and both-edges */
> -	if (flow_type != IRQ_TYPE_NONE &&
> -		(flow_type & IRQ_TYPE_EDGE_BOTH) != IRQ_TYPE_EDGE_BOTH)
> -		return -EINVAL;
> -
> -	return 0;
> -}
> -
> -static const struct irq_chip idi_48_irqchip = {
> -	.name = "104-idi-48",
> -	.irq_ack = idi_48_irq_ack,
> -	.irq_mask = idi_48_irq_mask,
> -	.irq_unmask = idi_48_irq_unmask,
> -	.irq_set_type = idi_48_irq_set_type,
> -	.flags = IRQCHIP_IMMUTABLE,
> -	GPIOCHIP_IRQ_RESOURCE_HELPERS,
> +static const struct regmap_range idi_48_wr_ranges[] = {
> +	regmap_reg_range(0x0, 0x6),
> +};
> +static const struct regmap_range idi_48_rd_ranges[] = {
> +	regmap_reg_range(0x0, 0x2), regmap_reg_range(0x4, 0x7),
> +};
> +static const struct regmap_range idi_48_precious_ranges[] = {
> +	regmap_reg_range(0x7, 0x7),
> +};
> +static const struct regmap_access_table idi_48_wr_table = {
> +	.no_ranges = idi_48_wr_ranges,
> +	.n_no_ranges = ARRAY_SIZE(idi_48_wr_ranges),
> +};
> +static const struct regmap_access_table idi_48_rd_table = {
> +	.yes_ranges = idi_48_rd_ranges,
> +	.n_yes_ranges = ARRAY_SIZE(idi_48_rd_ranges),
> +};
> +static const struct regmap_access_table idi_48_precious_table = {
> +	.yes_ranges = idi_48_precious_ranges,
> +	.n_yes_ranges = ARRAY_SIZE(idi_48_precious_ranges),
> +};
> +static const struct regmap_config idi48_regmap_config = {
> +	.reg_bits = 8,
> +	.reg_stride = 1,
> +	.val_bits = 8,
> +	.io_port = true,
> +	.max_register = 0x6,
> +	.wr_table = &idi_48_wr_table,
> +	.rd_table = &idi_48_rd_table,
> +	.precious_table = &idi_48_precious_table,
>  };
>  
> -static irqreturn_t idi_48_irq_handler(int irq, void *dev_id)
> -{
> -	struct idi_48_gpio *const idi48gpio = dev_id;
> -	unsigned long cos_status;
> -	unsigned long boundary;
> -	unsigned long irq_mask;
> -	unsigned long bit_num;
> -	unsigned long gpio;
> -	struct gpio_chip *const chip = &idi48gpio->chip;
> -
> -	spin_lock(&idi48gpio->lock);
> -
> -	cos_status = ioread8(&idi48gpio->reg->irq);
> -
> -	/* IRQ Status (bit 6) is active low (0 = IRQ generated by device) */
> -	if (cos_status & BIT(6)) {
> -		spin_unlock(&idi48gpio->lock);
> -		return IRQ_NONE;
> -	}
> -
> -	/* Bit 0-5 indicate which Change-Of-State boundary triggered the IRQ */
> -	cos_status &= 0x3F;
> -
> -	for_each_set_bit(boundary, &cos_status, 6) {
> -		irq_mask = idi48gpio->irq_mask[boundary];
> -
> -		for_each_set_bit(bit_num, &irq_mask, 8) {
> -			gpio = bit_num + boundary * 8;
> +#define IDI48_NGPIO 48
>  
> -			generic_handle_domain_irq(chip->irq.domain,
> -						  gpio);
> -		}
> +#define IDI48_REGMAP_IRQ(_id)						\
> +	[_id] = {							\
> +		.mask = BIT((_id) / 8),					\
> +		.type = { .types_supported = IRQ_TYPE_EDGE_BOTH },	\
>  	}
>  
> -	spin_unlock(&idi48gpio->lock);
> -
> -	return IRQ_HANDLED;
> -}
> +static const struct regmap_irq idi48_regmap_irqs[IDI48_NGPIO] = {
> +	IDI48_REGMAP_IRQ(0), IDI48_REGMAP_IRQ(1), IDI48_REGMAP_IRQ(2), /* 0-2 */
> +	IDI48_REGMAP_IRQ(3), IDI48_REGMAP_IRQ(4), IDI48_REGMAP_IRQ(5), /* 3-5 */
> +	IDI48_REGMAP_IRQ(6), IDI48_REGMAP_IRQ(7), IDI48_REGMAP_IRQ(8), /* 6-8 */
> +	IDI48_REGMAP_IRQ(9), IDI48_REGMAP_IRQ(10), IDI48_REGMAP_IRQ(11), /* 9-11 */
> +	IDI48_REGMAP_IRQ(12), IDI48_REGMAP_IRQ(13), IDI48_REGMAP_IRQ(14), /* 12-14 */
> +	IDI48_REGMAP_IRQ(15), IDI48_REGMAP_IRQ(16), IDI48_REGMAP_IRQ(17), /* 15-17 */
> +	IDI48_REGMAP_IRQ(18), IDI48_REGMAP_IRQ(19), IDI48_REGMAP_IRQ(20), /* 18-20 */
> +	IDI48_REGMAP_IRQ(21), IDI48_REGMAP_IRQ(22), IDI48_REGMAP_IRQ(23), /* 21-23 */
> +	IDI48_REGMAP_IRQ(24), IDI48_REGMAP_IRQ(25), IDI48_REGMAP_IRQ(26), /* 24-26 */
> +	IDI48_REGMAP_IRQ(27), IDI48_REGMAP_IRQ(28), IDI48_REGMAP_IRQ(29), /* 27-29 */
> +	IDI48_REGMAP_IRQ(30), IDI48_REGMAP_IRQ(31), IDI48_REGMAP_IRQ(32), /* 30-32 */
> +	IDI48_REGMAP_IRQ(33), IDI48_REGMAP_IRQ(34), IDI48_REGMAP_IRQ(35), /* 33-35 */
> +	IDI48_REGMAP_IRQ(36), IDI48_REGMAP_IRQ(37), IDI48_REGMAP_IRQ(38), /* 36-38 */
> +	IDI48_REGMAP_IRQ(39), IDI48_REGMAP_IRQ(40), IDI48_REGMAP_IRQ(41), /* 39-41 */
> +	IDI48_REGMAP_IRQ(42), IDI48_REGMAP_IRQ(43), IDI48_REGMAP_IRQ(44), /* 42-44 */
> +	IDI48_REGMAP_IRQ(45), IDI48_REGMAP_IRQ(46), IDI48_REGMAP_IRQ(47), /* 45-47 */
> +};
>  
> -#define IDI48_NGPIO 48
>  static const char *idi48_names[IDI48_NGPIO] = {
>  	"Bit 0 A", "Bit 1 A", "Bit 2 A", "Bit 3 A", "Bit 4 A", "Bit 5 A",
>  	"Bit 6 A", "Bit 7 A", "Bit 8 A", "Bit 9 A", "Bit 10 A", "Bit 11 A",
> @@ -228,22 +164,14 @@ static const char *idi48_names[IDI48_NGPIO] = {
>  	"Bit 18 B", "Bit 19 B", "Bit 20 B", "Bit 21 B", "Bit 22 B", "Bit 23 B"
>  };
>  
> -static int idi_48_irq_init_hw(struct gpio_chip *gc)
> -{
> -	struct idi_48_gpio *const idi48gpio = gpiochip_get_data(gc);
> -
> -	/* Disable IRQ by default */
> -	iowrite8(0, &idi48gpio->reg->irq);
> -	ioread8(&idi48gpio->reg->irq);
> -
> -	return 0;
> -}
> -
>  static int idi_48_probe(struct device *dev, unsigned int id)
>  {
>  	struct idi_48_gpio *idi48gpio;
>  	const char *const name = dev_name(dev);
> -	struct gpio_irq_chip *girq;
> +	void __iomem *regs;
> +	struct regmap *map;
> +	struct regmap_irq_chip *chip;
> +	struct regmap_irq_chip_data *chip_data;
>  	int err;
>  
>  	idi48gpio = devm_kzalloc(dev, sizeof(*idi48gpio), GFP_KERNEL);
> @@ -256,9 +184,32 @@ static int idi_48_probe(struct device *dev, unsigned int id)
>  		return -EBUSY;
>  	}
>  
> -	idi48gpio->reg = devm_ioport_map(dev, base[id], IDI_48_EXTENT);
> -	if (!idi48gpio->reg)
> +	regs = devm_ioport_map(dev, base[id], IDI_48_EXTENT);
> +	if (!regs)
>  		return -ENOMEM;
> +	idi48gpio->reg = regs;
> +
> +	map = devm_regmap_init_mmio(dev, regs, &idi48_regmap_config);
> +	if (IS_ERR(map))
> +		return dev_err_probe(dev, PTR_ERR(map),
> +				     "Unable to initialize register map\n");
> +
> +	chip = devm_kzalloc(dev, sizeof(*chip), GFP_KERNEL);
> +	if (!chip)
> +		return -ENOMEM;
> +
> +	chip->name = name;
> +	chip->status_base = IDI48_IRQ_STATUS;
> +	chip->unmask_base = IDI48_IRQ_ENABLE;
> +	chip->clear_on_unmask = true;
> +	chip->num_regs = 1;
> +	chip->irqs = idi48_regmap_irqs;
> +	chip->num_irqs = ARRAY_SIZE(idi48_regmap_irqs);
> +
> +	err = devm_regmap_add_irq_chip(dev, map, irq[id], IRQF_SHARED, 0, chip,
> +				       &chip_data);
> +	if (err)
> +		return dev_err_probe(dev, err, "IRQ registration failed\n");
>  
>  	idi48gpio->chip.label = name;
>  	idi48gpio->chip.parent = dev;
> @@ -271,32 +222,14 @@ static int idi_48_probe(struct device *dev, unsigned int id)
>  	idi48gpio->chip.get = idi_48_gpio_get;
>  	idi48gpio->chip.get_multiple = idi_48_gpio_get_multiple;
>  
> -	girq = &idi48gpio->chip.irq;
> -	gpio_irq_chip_set_chip(girq, &idi_48_irqchip);
> -	/* This will let us handle the parent IRQ in the driver */
> -	girq->parent_handler = NULL;
> -	girq->num_parents = 0;
> -	girq->parents = NULL;
> -	girq->default_type = IRQ_TYPE_NONE;
> -	girq->handler = handle_edge_irq;
> -	girq->init_hw = idi_48_irq_init_hw;
> -
> -	spin_lock_init(&idi48gpio->lock);
> -
>  	err = devm_gpiochip_add_data(dev, &idi48gpio->chip, idi48gpio);
>  	if (err) {
>  		dev_err(dev, "GPIO registering failed (%d)\n", err);
>  		return err;
>  	}
>  
> -	err = devm_request_irq(dev, irq[id], idi_48_irq_handler, IRQF_SHARED,
> -		name, idi48gpio);
> -	if (err) {
> -		dev_err(dev, "IRQ handler registering failed (%d)\n", err);
> -		return err;
> -	}
> -
> -	return 0;
> +	return gpiochip_irqchip_add_domain(&idi48gpio->chip,
> +					   regmap_irq_get_domain(chip_data));
>  }
>  
>  static struct isa_driver idi_48_driver = {
> -- 
> 2.38.1
> 

-- 
With Best Regards,
Andy Shevchenko

Re: [PATCH v4 6/9] gpio: i8255: Migrate to gpio-regmap API

[Andy Shevchenko]

On Fri, Dec 02, 2022 at 11:27:12AM -0500, William Breathitt Gray wrote:
> 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 gpio-regmap API, the i8255 library is reduced to
> simply a devm_i8255_regmap_register() function, a configuration
> structure struct i8255_regmap_config, and a helper macro
> i8255_volatile_regmap_range() provided to simplify volatile PPI register
> hinting for the regmap.
> 
> Legacy functions and code will be removed once all consumers have
> migrated to the new i8255 library interface.

Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>

> Suggested-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
> Signed-off-by: William Breathitt Gray <william.gray@linaro.org>
> ---
>  drivers/gpio/Kconfig      |   1 +
>  drivers/gpio/gpio-i8255.c | 119 ++++++++++++++++++++++++++++++++++----
>  drivers/gpio/gpio-i8255.h |  28 +++++++++
>  3 files changed, 136 insertions(+), 12 deletions(-)
> 
> diff --git a/drivers/gpio/Kconfig b/drivers/gpio/Kconfig
> index dd34039fc31b..88dfdc62992f 100644
> --- a/drivers/gpio/Kconfig
> +++ b/drivers/gpio/Kconfig
> @@ -831,6 +831,7 @@ menu "Port-mapped I/O GPIO drivers"
>  
>  config GPIO_I8255
>  	tristate
> +	select GPIO_REGMAP
>  	help
>  	  Enables support for the i8255 interface library functions. The i8255
>  	  interface library provides functions to facilitate communication with
> diff --git a/drivers/gpio/gpio-i8255.c b/drivers/gpio/gpio-i8255.c
> index 9b97db418df1..9ecb2e9b97f9 100644
> --- a/drivers/gpio/gpio-i8255.c
> +++ b/drivers/gpio/gpio-i8255.c
> @@ -4,23 +4,31 @@
>   * Copyright (C) 2022 William Breathitt Gray
>   */
>  #include <linux/bitmap.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-i8255.h"
>  
> +#define I8255_NGPIO 24
> +#define I8255_NGPIO_PER_REG 8
>  #define I8255_CONTROL_PORTC_LOWER_DIRECTION BIT(0)
>  #define I8255_CONTROL_PORTB_DIRECTION BIT(1)
>  #define I8255_CONTROL_PORTC_UPPER_DIRECTION BIT(3)
>  #define I8255_CONTROL_PORTA_DIRECTION BIT(4)
>  #define I8255_CONTROL_MODE_SET BIT(7)
> -#define I8255_PORTA 0
> -#define I8255_PORTB 1
> -#define I8255_PORTC 2
> +#define I8255_PORTA 0x0
> +#define I8255_PORTB 0x1
> +#define I8255_PORTC 0x2
> +#define I8255_CONTROL 0x3
> +#define I8255_REG_DAT_BASE I8255_PORTA
> +#define I8255_REG_DIR_IN_BASE I8255_CONTROL
>  
>  static int i8255_get_port(struct i8255 __iomem *const ppi,
>  			  const unsigned long io_port, const unsigned long mask)
> @@ -31,20 +39,19 @@ static int i8255_get_port(struct i8255 __iomem *const ppi,
>  	return ioread8(&ppi[bank].port[ppi_port]) & mask;
>  }
>  
> -static u8 i8255_direction_mask(const unsigned long offset)
> +static int i8255_direction_mask(const unsigned int offset)
>  {
> -	const unsigned long port_offset = offset % 8;
> -	const unsigned long io_port = offset / 8;
> -	const unsigned long ppi_port = io_port % 3;
> +	const unsigned int stride = offset / I8255_NGPIO_PER_REG;
> +	const unsigned int line = offset % I8255_NGPIO_PER_REG;
>  
> -	switch (ppi_port) {
> +	switch (stride) {
>  	case I8255_PORTA:
>  		return I8255_CONTROL_PORTA_DIRECTION;
>  	case I8255_PORTB:
>  		return I8255_CONTROL_PORTB_DIRECTION;
>  	case I8255_PORTC:
>  		/* Port C can be configured by nibble */
> -		if (port_offset >= 4)
> +		if (line >= 4)
>  			return I8255_CONTROL_PORTC_UPPER_DIRECTION;
>  		return I8255_CONTROL_PORTC_LOWER_DIRECTION;
>  	default:
> @@ -53,6 +60,49 @@ static u8 i8255_direction_mask(const unsigned long offset)
>  	}
>  }
>  
> +static int i8255_ppi_init(struct regmap *const map, const unsigned int base)
> +{
> +	int err;
> +
> +	/* Configure all ports to MODE 0 output mode */
> +	err = regmap_write(map, base + I8255_CONTROL, I8255_CONTROL_MODE_SET);
> +	if (err)
> +		return err;
> +
> +	/* Initialize all GPIO to output 0 */
> +	err = regmap_write(map, base + I8255_PORTA, 0x00);
> +	if (err)
> +		return err;
> +	err = regmap_write(map, base + I8255_PORTB, 0x00);
> +	if (err)
> +		return err;
> +	return regmap_write(map, base + I8255_PORTC, 0x00);
> +}
> +
> +static int i8255_reg_mask_xlate(struct gpio_regmap *gpio, unsigned int base,
> +				unsigned int offset, unsigned int *reg,
> +				unsigned int *mask)
> +{
> +	const unsigned int ppi = offset / I8255_NGPIO;
> +	const unsigned int ppi_offset = offset % I8255_NGPIO;
> +	const unsigned int stride = ppi_offset / I8255_NGPIO_PER_REG;
> +	const unsigned int line = ppi_offset % I8255_NGPIO_PER_REG;
> +
> +	switch (base) {
> +	case I8255_REG_DAT_BASE:
> +		*reg = base + stride + ppi * 4;
> +		*mask = BIT(line);
> +		return 0;
> +	case I8255_REG_DIR_IN_BASE:
> +		*reg = base + ppi * 4;
> +		*mask = i8255_direction_mask(ppi_offset);
> +		return 0;
> +	default:
> +		/* Should never reach this path */
> +		return -EINVAL;
> +	}
> +}
> +
>  static void i8255_set_port(struct i8255 __iomem *const ppi,
>  			   struct i8255_state *const state,
>  			   const unsigned long io_port,
> @@ -93,7 +143,7 @@ void i8255_direction_input(struct i8255 __iomem *const ppi,
>  	spin_lock_irqsave(&state[bank].lock, flags);
>  
>  	state[bank].control_state |= I8255_CONTROL_MODE_SET;
> -	state[bank].control_state |= i8255_direction_mask(offset);
> +	state[bank].control_state |= i8255_direction_mask(offset % 24);
>  
>  	iowrite8(state[bank].control_state, &ppi[bank].control);
>  
> @@ -125,7 +175,7 @@ void i8255_direction_output(struct i8255 __iomem *const ppi,
>  	spin_lock_irqsave(&state[bank].lock, flags);
>  
>  	state[bank].control_state |= I8255_CONTROL_MODE_SET;
> -	state[bank].control_state &= ~i8255_direction_mask(offset);
> +	state[bank].control_state &= ~i8255_direction_mask(offset % 24);
>  
>  	iowrite8(state[bank].control_state, &ppi[bank].control);
>  
> @@ -165,7 +215,7 @@ int i8255_get_direction(const struct i8255_state *const state,
>  	const unsigned long io_port = offset / 8;
>  	const unsigned long bank = io_port / 3;
>  
> -	return !!(state[bank].control_state & i8255_direction_mask(offset));
> +	return !!(state[bank].control_state & i8255_direction_mask(offset % 24));
>  }
>  EXPORT_SYMBOL_NS_GPL(i8255_get_direction, I8255);
>  
> @@ -282,6 +332,51 @@ void i8255_state_init(struct i8255_state *const state,
>  }
>  EXPORT_SYMBOL_NS_GPL(i8255_state_init, I8255);
>  
> +/**
> + * devm_i8255_regmap_register - Register an i8255 GPIO controller
> + * @dev:	device that is registering this i8255 GPIO device
> + * @config:	configuration for i8255_regmap_config
> + *
> + * Registers an Intel 8255 Programmable Peripheral Interface GPIO controller.
> + * Returns 0 on success and negative error number on failure.
> + */
> +int devm_i8255_regmap_register(struct device *const dev,
> +			       const struct i8255_regmap_config *const config)
> +{
> +	struct gpio_regmap_config gpio_config = {0};
> +	unsigned long i;
> +	int err;
> +
> +	if (!config->parent)
> +		return -EINVAL;
> +
> +	if (!config->map)
> +		return -EINVAL;
> +
> +	if (!config->num_ppi)
> +		return -EINVAL;
> +
> +	for (i = 0; i < config->num_ppi; i++) {
> +		err = i8255_ppi_init(config->map, i * 4);
> +		if (err)
> +			return err;
> +	}
> +
> +	gpio_config.parent = config->parent;
> +	gpio_config.regmap = config->map;
> +	gpio_config.ngpio = I8255_NGPIO * config->num_ppi;
> +	gpio_config.names = config->names;
> +	gpio_config.reg_dat_base = GPIO_REGMAP_ADDR(I8255_REG_DAT_BASE);
> +	gpio_config.reg_set_base = GPIO_REGMAP_ADDR(I8255_REG_DAT_BASE);
> +	gpio_config.reg_dir_in_base = GPIO_REGMAP_ADDR(I8255_REG_DIR_IN_BASE);
> +	gpio_config.ngpio_per_reg = I8255_NGPIO_PER_REG;
> +	gpio_config.irq_domain = config->domain;
> +	gpio_config.reg_mask_xlate = i8255_reg_mask_xlate;
> +
> +	return PTR_ERR_OR_ZERO(devm_gpio_regmap_register(dev, &gpio_config));
> +}
> +EXPORT_SYMBOL_NS_GPL(devm_i8255_regmap_register, I8255);
> +
>  MODULE_AUTHOR("William Breathitt Gray");
>  MODULE_DESCRIPTION("Intel 8255 Programmable Peripheral Interface");
>  MODULE_LICENSE("GPL");
> diff --git a/drivers/gpio/gpio-i8255.h b/drivers/gpio/gpio-i8255.h
> index d9084aae9446..3daa0b145890 100644
> --- a/drivers/gpio/gpio-i8255.h
> +++ b/drivers/gpio/gpio-i8255.h
> @@ -26,6 +26,34 @@ struct i8255_state {
>  	u8 control_state;
>  };
>  
> +struct device;
> +struct irq_domain;
> +struct regmap;
> +
> +#define i8255_volatile_regmap_range(_base) regmap_reg_range(_base, _base + 0x2)
> +
> +/**
> + * struct i8255_regmap_config - Configuration for the register map of an i8255
> + * @parent:	parent device
> + * @map:	regmap for the i8255
> + * @num_ppi:	number of i8255 Programmable Peripheral Interface
> + * @names:	(optional) array of names for gpios
> + * @domain:	(optional) IRQ domain if the controller is interrupt-capable
> + *
> + * Note: The regmap is expected to have cache enabled and i8255 control
> + * registers not marked as volatile.
> + */
> +struct i8255_regmap_config {
> +	struct device *parent;
> +	struct regmap *map;
> +	int num_ppi;
> +	const char *const *names;
> +	struct irq_domain *domain;
> +};
> +
> +int devm_i8255_regmap_register(struct device *dev,
> +			       const struct i8255_regmap_config *config);
> +
>  void i8255_direction_input(struct i8255 __iomem *ppi, struct i8255_state *state,
>  			   unsigned long offset);
>  void i8255_direction_output(struct i8255 __iomem *ppi,
> -- 
> 2.38.1
> 

-- 
With Best Regards,
Andy Shevchenko

Re: [PATCH v4 0/9] Migrate i8255 GPIO drivers to regmap API

[Bartosz Golaszewski]

On Fri, Dec 2, 2022 at 5:27 PM William Breathitt Gray
<william.gray@linaro.org> wrote:
>
> Changes in v4:
>  - Align trailing '\' characters in macros to same column in 104-dio-48e
>    and 104-idi-48
>  - Remove superfluous trailing commas in macros in 104-dio-48e and
>    104-idi-48
>  - Simplify dio48e_handle_mask_sync() regmap_* calls error checks to
>    return error codes directly
>  - Refactor dio48e_irq_init_hw() for regmap and comment about spurious
>    interrupts; in theory this should be enough to prevent spurious
>    interrupts before the system is ready, but we can pass this function
>    as a callback where needed in the future
>  - Cleanup '{0}' as '{}' in probe() callbacks for 104-dio-48e,
>    104-idi-48, and gpio-mm
>  - Utilize dev_err_probe() in probe() callbacks for 104-dio-48e and
>    104-idi-48
>  - Provide convenience comments for idi48_regmap_irqs initialization
>    list
>  - Replace header includes with forward declarations in gpio-i8255.h
>
> 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-dio-48e and gpio-mm modules depend on
> the i8255 library and are thus updated accordingly.
>
> The 104-IDI-48 is hardwired as an input-only device. Because the i8255
> control registers are not exposed on the 104-IDI-48, the i8255 library
> doesn't provide much benefit here. In this case it's simpler to utilize
> the gpio_regmap API directly, so this patch series does such and removes
> the i8255 library dependency from the 104-idi-48 module.
>
> The first patch in this series adjusts gpio_regmap to always set
> gpio_chip get_direction. This patch is mostly independent of the rest of
> the patches in the series and can be picked up separately if desired.
> I'm including it here because it allows the input-only 104-idi-48 driver
> to continue reporting offset directions after migrating to gpio_regmap.
>
> A handle_mask_sync() callback is introduced for the regmap_irq API. This
> is used by the 104-dio-48e driver to handle its enable/disable interrupt
> functionality. The 104-DIO-48E has a single register to handle
> enabling/disabling interrupts: a write of any value to this register
> enables interrupts, while any read disables interrupts.
>
> By leveraging the gpio_regmap API, the i8255 library is reduced to
> simply a devm_i8255_regmap_register() function, a configuration
> structure struct i8255_regmap_config, and a helper macro
> i8255_volatile_regmap_range() provided to simplify volatile PPI register
> hinting for the regmap.
>
> The regmap_irq API is leveraged by the 104-idi-48 and 104-dio-48e
> modules to support their IRQ functionality. Do their respective regmap
> configurations need use_hwlock set to true in this case, or is adequate
> locking already handled by the regmap_irq API?
>
> William Breathitt Gray (9):
>   gpio: regmap: Always set gpio_chip get_direction
>   regmap-irq: Add handle_mask_sync() callback
>   gpio: 104-dio-48e: Migrate to the regmap-irq API
>   gpio: 104-idi-48: Migrate to the regmap-irq API
>   gpio: 104-idi-48: Migrate to gpio-regmap API
>   gpio: i8255: Migrate to gpio-regmap API
>   gpio: 104-dio-48e: Migrate to regmap API
>   gpio: gpio-mm: Migrate to regmap API
>   gpio: i8255: Remove unused legacy interface
>
>  drivers/base/regmap/regmap-irq.c |  44 +++-
>  drivers/gpio/Kconfig             |   5 +-
>  drivers/gpio/gpio-104-dio-48e.c  | 391 ++++++++++---------------------
>  drivers/gpio/gpio-104-idi-48.c   | 336 +++++++++-----------------
>  drivers/gpio/gpio-gpio-mm.c      | 154 +++---------
>  drivers/gpio/gpio-i8255.c        | 320 +++++++------------------
>  drivers/gpio/gpio-i8255.h        |  54 ++---
>  drivers/gpio/gpio-regmap.c       |   7 +-
>  include/linux/regmap.h           |   5 +
>  9 files changed, 416 insertions(+), 900 deletions(-)
>
>
> base-commit: 3b7c7478eda00945987d45f902bc3942c89243d3
> --
> 2.38.1
>

It's pretty late in the release cycle and this touches several
existing drivers so I will not take it for v6.2. Please rebase and
resend once v6.3-rc1 is out.

Bart