Merge branch 'ib-pca953x-config' into devel

8 files changed, 127 insertions, 18 deletions

diff --git a/Documentation/devicetree/bindings/gpio/gpio.txt b/Documentation/devicetree/bindings/gpio/gpio.txt
index f0ba154b5723..a8895d339bfe 100644
--- a/Documentation/devicetree/bindings/gpio/gpio.txt
+++ b/Documentation/devicetree/bindings/gpio/gpio.txt
@@ -67,6 +67,18 @@ Optional standard bitfield specifiers for the last cell:
            https://en.wikipedia.org/wiki/Open_collector
 - Bit 3: 0 means the output should be maintained during sleep/low-power mode
          1 means the output state can be lost during sleep/low-power mode
+- Bit 4: 0 means no pull-up resistor should be enabled
+         1 means a pull-up resistor should be enabled
+         This setting only applies to hardware with a simple on/off
+         control for pull-up configuration. If the hardware has more
+         elaborate pull-up configuration, it should be represented
+         using a pin control binding.
+- Bit 5: 0 means no pull-down resistor should be enabled
+         1 means a pull-down resistor should be enabled
+         This setting only applies to hardware with a simple on/off
+         control for pull-down configuration. If the hardware has more
+         elaborate pull-down configuration, it should be represented
+         using a pin control binding.
 
 1.1) GPIO specifier best practices
 ----------------------------------
diff --git a/drivers/gpio/gpio-pca953x.c b/drivers/gpio/gpio-pca953x.c
index 83d45f00e4d0..1e5579acd275 100644
--- a/drivers/gpio/gpio-pca953x.c
+++ b/drivers/gpio/gpio-pca953x.c
@@ -179,6 +179,8 @@ static int pca953x_bank_shift(struct pca953x_chip *chip)
 #define PCA957x_BANK_OUTPUT	BIT(5)
 
 #define PCAL9xxx_BANK_IN_LATCH	BIT(8 + 2)
+#define PCAL9xxx_BANK_PULL_EN	BIT(8 + 3)
+#define PCAL9xxx_BANK_PULL_SEL	BIT(8 + 4)
 #define PCAL9xxx_BANK_IRQ_MASK	BIT(8 + 5)
 #define PCAL9xxx_BANK_IRQ_STAT	BIT(8 + 6)
 
@@ -200,6 +202,8 @@ static int pca953x_bank_shift(struct pca953x_chip *chip)
  * - Extended set, above 0x40, often chip specific.
  *   - PCAL6524/PCAL9555A with custom PCAL IRQ handling:
  *     Input latch register		0x40 + 2 * bank_size	RW
+ *     Pull-up/pull-down enable reg	0x40 + 3 * bank_size    RW
+ *     Pull-up/pull-down select reg	0x40 + 4 * bank_size    RW
  *     Interrupt mask register		0x40 + 5 * bank_size	RW
  *     Interrupt status register	0x40 + 6 * bank_size	R
  *
@@ -248,7 +252,8 @@ static bool pca953x_readable_register(struct device *dev, unsigned int reg)
 	}
 
 	if (chip->driver_data & PCA_PCAL) {
-		bank |= PCAL9xxx_BANK_IN_LATCH | PCAL9xxx_BANK_IRQ_MASK |
+		bank |= PCAL9xxx_BANK_IN_LATCH | PCAL9xxx_BANK_PULL_EN |
+			PCAL9xxx_BANK_PULL_SEL | PCAL9xxx_BANK_IRQ_MASK |
 			PCAL9xxx_BANK_IRQ_STAT;
 	}
 
@@ -269,7 +274,8 @@ static bool pca953x_writeable_register(struct device *dev, unsigned int reg)
 	}
 
 	if (chip->driver_data & PCA_PCAL)
-		bank |= PCAL9xxx_BANK_IN_LATCH | PCAL9xxx_BANK_IRQ_MASK;
+		bank |= PCAL9xxx_BANK_IN_LATCH | PCAL9xxx_BANK_PULL_EN |
+			PCAL9xxx_BANK_PULL_SEL | PCAL9xxx_BANK_IRQ_MASK;
 
 	return pca953x_check_register(chip, reg, bank);
 }
@@ -474,6 +480,61 @@ exit:
 	mutex_unlock(&chip->i2c_lock);
 }
 
+static int pca953x_gpio_set_pull_up_down(struct pca953x_chip *chip,
+					 unsigned int offset,
+					 unsigned long config)
+{
+	u8 pull_en_reg = pca953x_recalc_addr(chip, PCAL953X_PULL_EN, offset,
+					     true, false);
+	u8 pull_sel_reg = pca953x_recalc_addr(chip, PCAL953X_PULL_SEL, offset,
+					      true, false);
+	u8 bit = BIT(offset % BANK_SZ);
+	int ret;
+
+	/*
+	 * pull-up/pull-down configuration requires PCAL extended
+	 * registers
+	 */
+	if (!(chip->driver_data & PCA_PCAL))
+		return -ENOTSUPP;
+
+	mutex_lock(&chip->i2c_lock);
+
+	/* Disable pull-up/pull-down */
+	ret = regmap_write_bits(chip->regmap, pull_en_reg, bit, 0);
+	if (ret)
+		goto exit;
+
+	/* Configure pull-up/pull-down */
+	if (config == PIN_CONFIG_BIAS_PULL_UP)
+		ret = regmap_write_bits(chip->regmap, pull_sel_reg, bit, bit);
+	else if (config == PIN_CONFIG_BIAS_PULL_DOWN)
+		ret = regmap_write_bits(chip->regmap, pull_sel_reg, bit, 0);
+	if (ret)
+		goto exit;
+
+	/* Enable pull-up/pull-down */
+	ret = regmap_write_bits(chip->regmap, pull_en_reg, bit, bit);
+
+exit:
+	mutex_unlock(&chip->i2c_lock);
+	return ret;
+}
+
+static int pca953x_gpio_set_config(struct gpio_chip *gc, unsigned int offset,
+				   unsigned long config)
+{
+	struct pca953x_chip *chip = gpiochip_get_data(gc);
+
+	switch (config) {
+	case PIN_CONFIG_BIAS_PULL_UP:
+	case PIN_CONFIG_BIAS_PULL_DOWN:
+		return pca953x_gpio_set_pull_up_down(chip, offset, config);
+	default:
+		return -ENOTSUPP;
+	}
+}
+
 static void pca953x_setup_gpio(struct pca953x_chip *chip, int gpios)
 {
 	struct gpio_chip *gc;
@@ -486,6 +547,7 @@ static void pca953x_setup_gpio(struct pca953x_chip *chip, int gpios)
 	gc->set = pca953x_gpio_set_value;
 	gc->get_direction = pca953x_gpio_get_direction;
 	gc->set_multiple = pca953x_gpio_set_multiple;
+	gc->set_config = pca953x_gpio_set_config;
 	gc->can_sleep = true;
 
 	gc->base = chip->gpio_start;
diff --git a/drivers/gpio/gpiolib-of.c b/drivers/gpio/gpiolib-of.c
index a6e1891217e2..9a8b78477f79 100644
--- a/drivers/gpio/gpiolib-of.c
+++ b/drivers/gpio/gpiolib-of.c
@@ -345,6 +345,11 @@ struct gpio_desc *of_find_gpio(struct device *dev, const char *con_id,
 	if (of_flags & OF_GPIO_TRANSITORY)
 		*flags |= GPIO_TRANSITORY;
 
+	if (of_flags & OF_GPIO_PULL_UP)
+		*flags |= GPIO_PULL_UP;
+	if (of_flags & OF_GPIO_PULL_DOWN)
+		*flags |= GPIO_PULL_DOWN;
+
 	return desc;
 }
 
diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c
index 361a09c8138a..9be4c9401172 100644
--- a/drivers/gpio/gpiolib.c
+++ b/drivers/gpio/gpiolib.c
@@ -2555,6 +2555,14 @@ EXPORT_SYMBOL_GPL(gpiochip_free_own_desc);
  * rely on gpio_request() having been called beforehand.
  */
 
+static int gpio_set_config(struct gpio_chip *gc, unsigned offset,
+			   enum pin_config_param mode)
+{
+	unsigned long config = { PIN_CONF_PACKED(mode, 0) };
+
+	return gc->set_config ? gc->set_config(gc, offset, config) : -ENOTSUPP;
+}
+
 /**
  * gpiod_direction_input - set the GPIO direction to input
  * @desc:	GPIO to set to input
@@ -2602,20 +2610,19 @@ int gpiod_direction_input(struct gpio_desc *desc)
 	if (status == 0)
 		clear_bit(FLAG_IS_OUT, &desc->flags);
 
+	if (test_bit(FLAG_PULL_UP, &desc->flags))
+		gpio_set_config(chip, gpio_chip_hwgpio(desc),
+				PIN_CONFIG_BIAS_PULL_UP);
+	else if (test_bit(FLAG_PULL_DOWN, &desc->flags))
+		gpio_set_config(chip, gpio_chip_hwgpio(desc),
+				PIN_CONFIG_BIAS_PULL_DOWN);
+
 	trace_gpio_direction(desc_to_gpio(desc), 1, status);
 
 	return status;
 }
 EXPORT_SYMBOL_GPL(gpiod_direction_input);
 
-static int gpio_set_drive_single_ended(struct gpio_chip *gc, unsigned offset,
-				       enum pin_config_param mode)
-{
-	unsigned long config = { PIN_CONF_PACKED(mode, 0) };
-
-	return gc->set_config ? gc->set_config(gc, offset, config) : -ENOTSUPP;
-}
-
 static int gpiod_direction_output_raw_commit(struct gpio_desc *desc, int value)
 {
 	struct gpio_chip *gc = desc->gdev->chip;
@@ -2712,8 +2719,8 @@ int gpiod_direction_output(struct gpio_desc *desc, int value)
 	gc = desc->gdev->chip;
 	if (test_bit(FLAG_OPEN_DRAIN, &desc->flags)) {
 		/* First see if we can enable open drain in hardware */
-		ret = gpio_set_drive_single_ended(gc, gpio_chip_hwgpio(desc),
-						  PIN_CONFIG_DRIVE_OPEN_DRAIN);
+		ret = gpio_set_config(gc, gpio_chip_hwgpio(desc),
+				      PIN_CONFIG_DRIVE_OPEN_DRAIN);
 		if (!ret)
 			goto set_output_value;
 		/* Emulate open drain by not actively driving the line high */
@@ -2721,16 +2728,16 @@ int gpiod_direction_output(struct gpio_desc *desc, int value)
 			return gpiod_direction_input(desc);
 	}
 	else if (test_bit(FLAG_OPEN_SOURCE, &desc->flags)) {
-		ret = gpio_set_drive_single_ended(gc, gpio_chip_hwgpio(desc),
-						  PIN_CONFIG_DRIVE_OPEN_SOURCE);
+		ret = gpio_set_config(gc, gpio_chip_hwgpio(desc),
+				      PIN_CONFIG_DRIVE_OPEN_SOURCE);
 		if (!ret)
 			goto set_output_value;
 		/* Emulate open source by not actively driving the line low */
 		if (!value)
 			return gpiod_direction_input(desc);
 	} else {
-		gpio_set_drive_single_ended(gc, gpio_chip_hwgpio(desc),
-					    PIN_CONFIG_DRIVE_PUSH_PULL);
+		gpio_set_config(gc, gpio_chip_hwgpio(desc),
+				PIN_CONFIG_DRIVE_PUSH_PULL);
 	}
 
 set_output_value:
@@ -2762,7 +2769,7 @@ int gpiod_set_debounce(struct gpio_desc *desc, unsigned debounce)
 	}
 
 	config = pinconf_to_config_packed(PIN_CONFIG_INPUT_DEBOUNCE, debounce);
-	return chip->set_config(chip, gpio_chip_hwgpio(desc), config);
+	return gpio_set_config(chip, gpio_chip_hwgpio(desc), config);
 }
 EXPORT_SYMBOL_GPL(gpiod_set_debounce);
 
@@ -2799,7 +2806,7 @@ int gpiod_set_transitory(struct gpio_desc *desc, bool transitory)
 	packed = pinconf_to_config_packed(PIN_CONFIG_PERSIST_STATE,
 					  !transitory);
 	gpio = gpio_chip_hwgpio(desc);
-	rc = chip->set_config(chip, gpio, packed);
+	rc = gpio_set_config(chip, gpio, packed);
 	if (rc == -ENOTSUPP) {
 		dev_dbg(&desc->gdev->dev, "Persistence not supported for GPIO %d\n",
 				gpio);
@@ -4087,6 +4094,17 @@ int gpiod_configure_flags(struct gpio_desc *desc, const char *con_id,
 	if (lflags & GPIO_OPEN_SOURCE)
 		set_bit(FLAG_OPEN_SOURCE, &desc->flags);
 
+	if ((lflags & GPIO_PULL_UP) && (lflags & GPIO_PULL_DOWN)) {
+		gpiod_err(desc,
+			  "both pull-up and pull-down enabled, invalid configuration\n");
+		return -EINVAL;
+	}
+
+	if (lflags & GPIO_PULL_UP)
+		set_bit(FLAG_PULL_UP, &desc->flags);
+	else if (lflags & GPIO_PULL_DOWN)
+		set_bit(FLAG_PULL_DOWN, &desc->flags);
+
 	status = gpiod_set_transitory(desc, (lflags & GPIO_TRANSITORY));
 	if (status < 0)
 		return status;
diff --git a/drivers/gpio/gpiolib.h b/drivers/gpio/gpiolib.h
index bc57f0dc5953..078ab17b96bf 100644
--- a/drivers/gpio/gpiolib.h
+++ b/drivers/gpio/gpiolib.h
@@ -219,6 +219,8 @@ struct gpio_desc {
 #define FLAG_IRQ_IS_ENABLED 10	/* GPIO is connected to an enabled IRQ */
 #define FLAG_IS_HOGGED	11	/* GPIO is hogged */
 #define FLAG_TRANSITORY 12	/* GPIO may lose value in sleep or reset */
+#define FLAG_PULL_UP    13	/* GPIO has pull up enabled */
+#define FLAG_PULL_DOWN  14	/* GPIO has pull down enabled */
 
 	/* Connection label */
 	const char		*label;
diff --git a/include/dt-bindings/gpio/gpio.h b/include/dt-bindings/gpio/gpio.h
index 2cc10ae4bbb7..c029467e828b 100644
--- a/include/dt-bindings/gpio/gpio.h
+++ b/include/dt-bindings/gpio/gpio.h
@@ -33,4 +33,10 @@
 #define GPIO_PERSISTENT 0
 #define GPIO_TRANSITORY 8
 
+/* Bit 4 express pull up */
+#define GPIO_PULL_UP 16
+
+/* Bit 5 express pull down */
+#define GPIO_PULL_DOWN 32
+
 #endif
diff --git a/include/linux/gpio/machine.h b/include/linux/gpio/machine.h
index daa44eac9241..69673be10213 100644
--- a/include/linux/gpio/machine.h
+++ b/include/linux/gpio/machine.h
@@ -12,6 +12,8 @@ enum gpio_lookup_flags {
 	GPIO_OPEN_SOURCE = (1 << 2),
 	GPIO_PERSISTENT = (0 << 3),
 	GPIO_TRANSITORY = (1 << 3),
+	GPIO_PULL_UP = (1 << 4),
+	GPIO_PULL_DOWN = (1 << 5),
 };
 
 /**
diff --git a/include/linux/of_gpio.h b/include/linux/of_gpio.h
index 163b79ecd01a..f9737dea9d1f 100644
--- a/include/linux/of_gpio.h
+++ b/include/linux/of_gpio.h
@@ -28,6 +28,8 @@ enum of_gpio_flags {
 	OF_GPIO_SINGLE_ENDED = 0x2,
 	OF_GPIO_OPEN_DRAIN = 0x4,
 	OF_GPIO_TRANSITORY = 0x8,
+	OF_GPIO_PULL_UP = 0x10,
+	OF_GPIO_PULL_DOWN = 0x20,
 };
 
 #ifdef CONFIG_OF_GPIO