[PATCH v6 5/8] gpio: regmap: Add gpio_regmap_operation and value_xlate support

[Yu-Chun Lin <eleanor.lin@realtek.com>]

Extend the reg_mask_xlate callback with an operation type parameter
(enum gpio_regmap_operation) to allow drivers to return different
register/mask combinations depending on the specific GPIO operation.

In addition, introduce a new optional 'value_xlate' callback. This routine
allows drivers to translate or modify the register value and mask
immediately before a write operation. It is particularly useful for
hardware that requires additional control bits, such as a write-enable bit,
to be appended to the data dynamically.

Consequently, update all existing drivers utilizing the gpio-regmap
framework (across drivers/gpio, drivers/iio, and drivers/pinctrl)
to accommodate the new reg_mask_xlate function signature.

Suggested-by: Linus Walleij <linusw@kernel.org>
Signed-off-by: Yu-Chun Lin <eleanor.lin@realtek.com>
---
Changes in v6:
- Remove removed the hardcoded write-enable workarounds.
- Retain the necessary prototype updates in every driver using custom
reg_mask_xlate
- Add value_xlate to dynamically adjust the register mask and value right
before the actual register write operation.
---
 drivers/gpio/gpio-104-idi-48.c        |  7 +--
 drivers/gpio/gpio-i8255.c             |  4 +-
 drivers/gpio/gpio-idio-16.c           |  6 +--
 drivers/gpio/gpio-max7360.c           |  1 +
 drivers/gpio/gpio-pcie-idio-24.c      |  6 +--
 drivers/gpio/gpio-regmap.c            | 62 ++++++++++++++++++++++-----
 drivers/iio/adc/ad7173.c              |  8 ++--
 drivers/iio/addac/stx104.c            |  6 +--
 drivers/pinctrl/bcm/pinctrl-bcm63xx.c |  1 +
 drivers/pinctrl/pinctrl-tps6594.c     |  1 +
 include/linux/gpio/regmap.h           | 44 +++++++++++++++++--
 11 files changed, 115 insertions(+), 31 deletions(-)

diff --git a/drivers/gpio/gpio-104-idi-48.c b/drivers/gpio/gpio-104-idi-48.c
index ba73ee9c0c29..fb017569cfa8 100644
--- a/drivers/gpio/gpio-104-idi-48.c
+++ b/drivers/gpio/gpio-104-idi-48.c
@@ -36,9 +36,10 @@ MODULE_PARM_DESC(irq, "ACCES 104-IDI-48 interrupt line numbers");
 #define IDI48_IRQ_STATUS 0x7
 #define IDI48_IRQ_ENABLE IDI48_IRQ_STATUS
 
-static int idi_48_reg_mask_xlate(struct gpio_regmap *gpio, unsigned int base,
-				 unsigned int offset, unsigned int *reg,
-				 unsigned int *mask)
+static int idi_48_reg_mask_xlate(struct gpio_regmap *gpio,
+				 enum gpio_regmap_operation op,
+				 unsigned int base, unsigned int offset,
+				 unsigned int *reg, unsigned int *mask)
 {
 	const unsigned int line = offset % 8;
 	const unsigned int stride = offset / 8;
diff --git a/drivers/gpio/gpio-i8255.c b/drivers/gpio/gpio-i8255.c
index 953018bfa2b1..541a348447cd 100644
--- a/drivers/gpio/gpio-i8255.c
+++ b/drivers/gpio/gpio-i8255.c
@@ -67,8 +67,8 @@ static int i8255_ppi_init(struct regmap *const map, const unsigned int base)
 	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,
+static int i8255_reg_mask_xlate(struct gpio_regmap *gpio, enum gpio_regmap_operation op,
+				unsigned int base, unsigned int offset, unsigned int *reg,
 				unsigned int *mask)
 {
 	const unsigned int ppi = offset / I8255_NGPIO;
diff --git a/drivers/gpio/gpio-idio-16.c b/drivers/gpio/gpio-idio-16.c
index 4fbae6f6a497..9ac967c6b430 100644
--- a/drivers/gpio/gpio-idio-16.c
+++ b/drivers/gpio/gpio-idio-16.c
@@ -66,9 +66,9 @@ static int idio_16_handle_mask_sync(const int index, const unsigned int mask_buf
 	return 0;
 }
 
-static int idio_16_reg_mask_xlate(struct gpio_regmap *const gpio, const unsigned int base,
-				  const unsigned int offset, unsigned int *const reg,
-				  unsigned int *const mask)
+static int idio_16_reg_mask_xlate(struct gpio_regmap *const gpio, enum gpio_regmap_operation op,
+				  const unsigned int base, const unsigned int offset,
+				  unsigned int *const reg, unsigned int *const mask)
 {
 	unsigned int stride;
 
diff --git a/drivers/gpio/gpio-max7360.c b/drivers/gpio/gpio-max7360.c
index 07eda49f375b..6755d58c4534 100644
--- a/drivers/gpio/gpio-max7360.c
+++ b/drivers/gpio/gpio-max7360.c
@@ -93,6 +93,7 @@ static int max7360_set_gpos_count(struct device *dev, struct regmap *regmap)
 }
 
 static int max7360_gpio_reg_mask_xlate(struct gpio_regmap *gpio,
+				       enum gpio_regmap_operation op,
 				       unsigned int base, unsigned int offset,
 				       unsigned int *reg, unsigned int *mask)
 {
diff --git a/drivers/gpio/gpio-pcie-idio-24.c b/drivers/gpio/gpio-pcie-idio-24.c
index 80c0ba0afa67..b99f4863443d 100644
--- a/drivers/gpio/gpio-pcie-idio-24.c
+++ b/drivers/gpio/gpio-pcie-idio-24.c
@@ -225,9 +225,9 @@ static int idio_24_set_type_config(unsigned int **const buf, const unsigned int
 	return ret;
 }
 
-static int idio_24_reg_mask_xlate(struct gpio_regmap *const gpio, const unsigned int base,
-				  const unsigned int offset, unsigned int *const reg,
-				  unsigned int *const mask)
+static int idio_24_reg_mask_xlate(struct gpio_regmap *const gpio, enum gpio_regmap_operation op,
+				  const unsigned int base, const unsigned int offset,
+				  unsigned int *const reg, unsigned int *const mask)
 {
 	const unsigned int out_stride = offset / IDIO_24_NGPIO_PER_REG;
 	const unsigned int in_stride = (offset - 24) / IDIO_24_NGPIO_PER_REG;
diff --git a/drivers/gpio/gpio-regmap.c b/drivers/gpio/gpio-regmap.c
index 658b892b624c..aecc35f610dd 100644
--- a/drivers/gpio/gpio-regmap.c
+++ b/drivers/gpio/gpio-regmap.c
@@ -40,9 +40,16 @@ struct gpio_regmap {
 	struct regmap_irq_chip_data *irq_chip_data;
 #endif
 
-	int (*reg_mask_xlate)(struct gpio_regmap *gpio, unsigned int base,
-			      unsigned int offset, unsigned int *reg,
-			      unsigned int *mask);
+	int (*reg_mask_xlate)(struct gpio_regmap *gpio,
+			      enum gpio_regmap_operation op,
+			      unsigned int base, unsigned int offset,
+			      unsigned int *reg, unsigned int *mask);
+
+	int (*value_xlate)(struct gpio_regmap *gpio,
+			   enum gpio_regmap_operation op,
+			   unsigned int base, unsigned int offset,
+			   unsigned int reg, unsigned int *mask,
+			   unsigned int *val);
 
 	void *driver_data;
 };
@@ -56,6 +63,7 @@ static unsigned int gpio_regmap_addr(unsigned int addr)
 }
 
 static int gpio_regmap_simple_xlate(struct gpio_regmap *gpio,
+				    enum gpio_regmap_operation op,
 				    unsigned int base, unsigned int offset,
 				    unsigned int *reg, unsigned int *mask)
 {
@@ -71,7 +79,7 @@ static int gpio_regmap_simple_xlate(struct gpio_regmap *gpio,
 static int gpio_regmap_get(struct gpio_chip *chip, unsigned int offset)
 {
 	struct gpio_regmap *gpio = gpiochip_get_data(chip);
-	unsigned int base, val, reg, mask;
+	unsigned int base, val, reg, mask, dir_mask;
 	int ret;
 
 	/* we might not have an output register if we are input only */
@@ -80,7 +88,18 @@ static int gpio_regmap_get(struct gpio_chip *chip, unsigned int offset)
 	else
 		base = gpio_regmap_addr(gpio->reg_set_base);
 
-	ret = gpio->reg_mask_xlate(gpio, base, offset, &reg, &mask);
+	ret = gpio->reg_mask_xlate(gpio, GPIO_REGMAP_GET_OP, base, offset, &reg, &dir_mask);
+	if (ret)
+		return ret;
+
+	ret = regmap_read(gpio->regmap, reg, &val);
+	if (ret)
+		return ret;
+
+	if (val & dir_mask)
+		ret = gpio->reg_mask_xlate(gpio, GPIO_REGMAP_OUT, base, offset, &reg, &mask);
+	else
+		ret = gpio->reg_mask_xlate(gpio, GPIO_REGMAP_IN, base, offset, &reg, &mask);
 	if (ret)
 		return ret;
 
@@ -103,7 +122,7 @@ static int gpio_regmap_set(struct gpio_chip *chip, unsigned int offset,
 	unsigned int reg, mask, mask_val;
 	int ret;
 
-	ret = gpio->reg_mask_xlate(gpio, base, offset, &reg, &mask);
+	ret = gpio->reg_mask_xlate(gpio, GPIO_REGMAP_SET_OP, base, offset, &reg, &mask);
 	if (ret)
 		return ret;
 
@@ -112,6 +131,13 @@ static int gpio_regmap_set(struct gpio_chip *chip, unsigned int offset,
 	else
 		mask_val = 0;
 
+	if (gpio->value_xlate) {
+		ret = gpio->value_xlate(gpio, GPIO_REGMAP_SET_OP, base, offset,
+					reg, &mask, &mask_val);
+		if (ret)
+			return ret;
+	}
+
 	/* ignore input values which shadow the old output value */
 	if (gpio->reg_dat_base == gpio->reg_set_base)
 		ret = regmap_write_bits(gpio->regmap, reg, mask, mask_val);
@@ -125,7 +151,7 @@ static int gpio_regmap_set_with_clear(struct gpio_chip *chip,
 				      unsigned int offset, int val)
 {
 	struct gpio_regmap *gpio = gpiochip_get_data(chip);
-	unsigned int base, reg, mask;
+	unsigned int base, reg, mask, value = 0;
 	int ret;
 
 	if (val)
@@ -133,10 +159,17 @@ static int gpio_regmap_set_with_clear(struct gpio_chip *chip,
 	else
 		base = gpio_regmap_addr(gpio->reg_clr_base);
 
-	ret = gpio->reg_mask_xlate(gpio, base, offset, &reg, &mask);
+	ret = gpio->reg_mask_xlate(gpio, GPIO_REGMAP_SET_OP, base, offset, &reg, &mask);
 	if (ret)
 		return ret;
 
+	if (gpio->value_xlate) {
+		ret = gpio->value_xlate(gpio, GPIO_REGMAP_SET_OP, base, offset,
+					reg, &mask, &value);
+		if (ret)
+			return ret;
+	}
+
 	return regmap_write(gpio->regmap, reg, mask);
 }
 
@@ -183,7 +216,7 @@ static int gpio_regmap_get_direction(struct gpio_chip *chip,
 		return -ENOTSUPP;
 	}
 
-	ret = gpio->reg_mask_xlate(gpio, base, offset, &reg, &mask);
+	ret = gpio->reg_mask_xlate(gpio, GPIO_REGMAP_GET_DIR_OP, base, offset, &reg, &mask);
 	if (ret)
 		return ret;
 
@@ -237,7 +270,7 @@ static int gpio_regmap_set_direction(struct gpio_chip *chip,
 		return -ENOTSUPP;
 	}
 
-	ret = gpio->reg_mask_xlate(gpio, base, offset, &reg, &mask);
+	ret = gpio->reg_mask_xlate(gpio, GPIO_REGMAP_SET_DIR_OP, base, offset, &reg, &mask);
 	if (ret)
 		return ret;
 
@@ -246,6 +279,13 @@ static int gpio_regmap_set_direction(struct gpio_chip *chip,
 	else
 		val = output ? mask : 0;
 
+	if (gpio->value_xlate) {
+		ret = gpio->value_xlate(gpio, GPIO_REGMAP_SET_DIR_OP, base, offset,
+					reg, &mask, &val);
+		if (ret)
+			return ret;
+	}
+
 	return regmap_update_bits(gpio->regmap, reg, mask, val);
 }
 
@@ -413,6 +453,8 @@ struct gpio_regmap *gpio_regmap_register(const struct gpio_regmap_config *config
 	if (!gpio->reg_mask_xlate)
 		gpio->reg_mask_xlate = gpio_regmap_simple_xlate;
 
+	gpio->value_xlate = config->value_xlate;
+
 	ret = gpiochip_add_data(chip, gpio);
 	if (ret < 0)
 		goto err_free_bitmap_output;
diff --git a/drivers/iio/adc/ad7173.c b/drivers/iio/adc/ad7173.c
index 9ee65d63c525..f78e758706ed 100644
--- a/drivers/iio/adc/ad7173.c
+++ b/drivers/iio/adc/ad7173.c
@@ -560,8 +560,8 @@ static int ad4111_openwire_event(struct iio_dev *indio_dev,
 	return ret;
 }
 
-static int ad7173_mask_xlate(struct gpio_regmap *gpio, unsigned int base,
-			     unsigned int offset, unsigned int *reg,
+static int ad7173_mask_xlate(struct gpio_regmap *gpio, enum gpio_regmap_operation op,
+			     unsigned int base, unsigned int offset, unsigned int *reg,
 			     unsigned int *mask)
 {
 	*mask = AD7173_GPO_DATA(offset);
@@ -569,8 +569,8 @@ static int ad7173_mask_xlate(struct gpio_regmap *gpio, unsigned int base,
 	return 0;
 }
 
-static int ad4111_mask_xlate(struct gpio_regmap *gpio, unsigned int base,
-			     unsigned int offset, unsigned int *reg,
+static int ad4111_mask_xlate(struct gpio_regmap *gpio, enum gpio_regmap_operation op,
+			     unsigned int base, unsigned int offset, unsigned int *reg,
 			     unsigned int *mask)
 {
 	*mask = AD4111_GPO01_DATA(offset);
diff --git a/drivers/iio/addac/stx104.c b/drivers/iio/addac/stx104.c
index 7bdf2cb94176..6207eb2fac74 100644
--- a/drivers/iio/addac/stx104.c
+++ b/drivers/iio/addac/stx104.c
@@ -349,9 +349,9 @@ static const struct iio_chan_spec stx104_channels_diff[] = {
 	STX104_IN_CHAN(6, 1), STX104_IN_CHAN(7, 1)
 };
 
-static int stx104_reg_mask_xlate(struct gpio_regmap *const gpio, const unsigned int base,
-				 unsigned int offset, unsigned int *const reg,
-				 unsigned int *const mask)
+static int stx104_reg_mask_xlate(struct gpio_regmap *const gpio, enum gpio_regmap_operation op,
+				 const unsigned int base, unsigned int offset,
+				 unsigned int *const reg, unsigned int *const mask)
 {
 	/* Output lines are located at same register bit offsets as input lines */
 	if (offset >= 4)
diff --git a/drivers/pinctrl/bcm/pinctrl-bcm63xx.c b/drivers/pinctrl/bcm/pinctrl-bcm63xx.c
index a4aa4146b530..b41a3d16aabe 100644
--- a/drivers/pinctrl/bcm/pinctrl-bcm63xx.c
+++ b/drivers/pinctrl/bcm/pinctrl-bcm63xx.c
@@ -19,6 +19,7 @@
 #define BCM63XX_DATA_REG	0x0c
 
 static int bcm63xx_reg_mask_xlate(struct gpio_regmap *gpio,
+				  enum gpio_regmap_operation op,
 				  unsigned int base, unsigned int offset,
 				  unsigned int *reg, unsigned int *mask)
 {
diff --git a/drivers/pinctrl/pinctrl-tps6594.c b/drivers/pinctrl/pinctrl-tps6594.c
index 456a3cfc8de9..937fc9cb54b7 100644
--- a/drivers/pinctrl/pinctrl-tps6594.c
+++ b/drivers/pinctrl/pinctrl-tps6594.c
@@ -346,6 +346,7 @@ static struct tps6594_pinctrl tps6594_template_pinctrl = {
 };
 
 static int tps6594_gpio_regmap_xlate(struct gpio_regmap *gpio,
+				     enum gpio_regmap_operation op,
 				     unsigned int base, unsigned int offset,
 				     unsigned int *reg, unsigned int *mask)
 {
diff --git a/include/linux/gpio/regmap.h b/include/linux/gpio/regmap.h
index a3ba8242c353..45a30f50043f 100644
--- a/include/linux/gpio/regmap.h
+++ b/include/linux/gpio/regmap.h
@@ -13,6 +13,36 @@ struct regmap;
 #define GPIO_REGMAP_ADDR_ZERO ((unsigned int)(-1))
 #define GPIO_REGMAP_ADDR(addr) ((addr) ? : GPIO_REGMAP_ADDR_ZERO)
 
+/**
+ * enum gpio_regmap_operation - Operation type for reg_mask_xlate callback
+ *
+ * This enum is used to distinguish between different types of GPIO operations
+ * so that the reg_mask_xlate callback can return the appropriate mask for each
+ * operation type.
+ *
+ * Value operations:
+ * @GPIO_REGMAP_GET_OP: Mask for reading direction to detect if GPIO is input or output.
+ *                      Used in gpio_regmap_get() to determine the GPIO direction.
+ * @GPIO_REGMAP_IN: Mask for reading input value. Used when GPIO is configured as input.
+ * @GPIO_REGMAP_OUT: Mask for reading output value. Used when GPIO is configured as output.
+ *
+ * Output operations:
+ * @GPIO_REGMAP_SET_OP: Mask for setting GPIO output value.
+ *
+ * Direction operations:
+ * @GPIO_REGMAP_GET_DIR_OP: Mask for reading GPIO direction (input/output).
+ * @GPIO_REGMAP_SET_DIR_OP: Mask for setting GPIO direction (input/output).
+ *
+ */
+enum gpio_regmap_operation {
+	GPIO_REGMAP_GET_OP,
+	GPIO_REGMAP_SET_OP,
+	GPIO_REGMAP_GET_DIR_OP,
+	GPIO_REGMAP_SET_DIR_OP,
+	GPIO_REGMAP_IN,
+	GPIO_REGMAP_OUT,
+};
+
 /**
  * struct gpio_regmap_config - Description of a generic regmap gpio_chip.
  * @parent:		The parent device
@@ -55,6 +85,10 @@ struct regmap;
  *			is used.
  * @init_valid_mask:	(Optional) Routine to initialize @valid_mask, to be used
  *			if not all GPIOs are valid.
+ * @value_xlate:	(Optional) Routine to translate the register value and
+ *			mask before writing. This allows driver-specific logic
+ *			to append additional bits (like write-enable masks)
+ *			dynamically based on the current operation.
  * @drvdata:		(Optional) Pointer to driver specific data which is
  *			not used by gpio-remap but is provided "as is" to the
  *			driver callback(s).
@@ -104,14 +138,18 @@ struct gpio_regmap_config {
 	unsigned long regmap_irq_flags;
 #endif
 
-	int (*reg_mask_xlate)(struct gpio_regmap *gpio, unsigned int base,
-			      unsigned int offset, unsigned int *reg,
-			      unsigned int *mask);
+	int (*reg_mask_xlate)(struct gpio_regmap *gpio, enum gpio_regmap_operation,
+			      unsigned int base, unsigned int offset,
+			      unsigned int *reg, unsigned int *mask);
 
 	int (*init_valid_mask)(struct gpio_chip *gc,
 			       unsigned long *valid_mask,
 			       unsigned int ngpios);
 
+	int (*value_xlate)(struct gpio_regmap *gpio, enum gpio_regmap_operation,
+			   unsigned int base, unsigned int offset, unsigned int reg,
+			   unsigned int *mask, unsigned int *val);
+
 	void *drvdata;
 };
 
-- 
2.43.0