diff --git a/Documentation/devicetree/bindings/gpio/gpio.txt b/Documentation/devicetree/bindings/gpio/gpio.txt
index f0ba154b57231577d3a04634b0d6c94869fe8494..a8895d339bfea6d25720ca250e90bc9a3f4dc42d 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 83d45f00e4d0511c9648892823a8b63be6e5a471..1e5579acd2751b20358dbc0e152e4ecbc3708ffe 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 @@ static void pca953x_gpio_set_multiple(struct gpio_chip *gc,
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 a6e1891217e26880cb94bd2ec6b08289733f8c42..9a8b78477f792de412dd08d204a1e9ad16a9dad7 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 361a09c8138a79330cace80488d333f4b049982b..9be4c9401172d8fe1688febb74c589ee31cbfa25 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 bc57f0dc59532f9c0d085e74b9ebc0f0e5bb6841..078ab17b96bf4e84d52d2e159b4f6ee5b5adad77 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 2cc10ae4bbb7ba29bb7503992e1bd5c0036acc27..c029467e828b29f79dc4150792a4ed2fd87e00b2 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 daa44eac9241b008a3848ad76ef6b73dbf6495d0..69673be10213d94a839ac6c6d97bdc1e27e1aa57 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 163b79ecd01a39fb141ae8f6052f74fc86b93210..f9737dea9d1f945a574c25aea05d02144e185b13 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