pinctrl&gpio: add new interface to set pull-down/up

PD#142470: pinctrl&gpio: add new interface to set pull-down/up

1. add property file 'pull' in directory /sys/class/gpio/gpioX/
pull-up:      echo up > pull
pull-down:    echo down > pull
pull-disable: echo disable > pull

2. add new functions, as follows:
+ gpiod_set_pull(struct gpio_desc *desc, int value)
+ gpiod_set_pull_cansleep(struct gpio_desc *desc, int value)

'value' can be set:
GPIOD_PULL_DIS
GPIOD_PULL_DOWN
GPIOD_PULL_UP

Change-Id: Iba750729288651a897ebac827093ebc6c143f16b
Signed-off-by: xingyu.chen <xingyu.chen@amlogic.com>

drivers/amlogic/pinctrl/pinctrl-meson.c

@@ -658,6 +658,41 @@ static void meson_gpio_set(struct gpio_chip *chip, unsigned int gpio,
 			   value ? BIT(bit) : 0);
 }
 
+static int meson_gpio_pull_set(struct gpio_chip *chip, unsigned int gpio,
+	int value)
+{
+	struct meson_domain *domain = to_meson_domain(chip);
+	unsigned int reg, bit, pin;
+	struct meson_bank *bank;
+	int ret;
+
+	if ((value != GPIOD_PULL_DIS) && (value != GPIOD_PULL_DOWN)
+		&& (value != GPIOD_PULL_UP))
+		return -EINVAL;
+
+	pin = domain->data->pin_base + gpio;
+	ret = meson_get_bank(domain, pin, &bank);
+	if (ret)
+		return ret;
+
+	meson_calc_reg_and_bit(bank, pin, REG_PULLEN,
+				&reg, &bit);
+	ret = regmap_update_bits(domain->reg_pullen, reg,
+				BIT(bit),
+				(value == GPIOD_PULL_DIS) ? 0 : BIT(bit));
+	if (ret)
+		return ret;
+
+	meson_calc_reg_and_bit(bank, pin, REG_PULL, &reg, &bit);
+	ret = regmap_update_bits(domain->reg_pull, reg,
+				BIT(bit),
+				(value == GPIOD_PULL_DOWN) ? 0 : BIT(bit));
+	if (ret)
+		return ret;
+
+	return 0;
+}
+
 static int meson_gpio_get(struct gpio_chip *chip, unsigned int gpio)
 {
 	struct meson_domain *domain = to_meson_domain(chip);
@@ -1088,6 +1123,7 @@ static int meson_gpiolib_register(struct meson_pinctrl *pc)
 	domain->chip.direction_output = meson_gpio_direction_output;
 	domain->chip.get = meson_gpio_get;
 	domain->chip.set = meson_gpio_set;
+	domain->chip.set_pull = meson_gpio_pull_set;
 	domain->chip.base = domain->data->pin_base;
 	domain->chip.ngpio = domain->data->num_pins;
 	domain->chip.can_sleep = false;

drivers/gpio/gpiolib-sysfs.c

@@ -350,6 +350,30 @@ static ssize_t active_low_store(struct device *dev,
 }
 static DEVICE_ATTR_RW(active_low);
 
+#ifdef CONFIG_AMLOGIC_PINCTRL
+static ssize_t pull_store(struct device *dev,
+		struct device_attribute *attr, const char *buf, size_t size)
+{
+	struct gpiod_data  *data = dev_get_drvdata(dev);
+	struct gpio_desc *desc = data->desc;
+	ssize_t    status;
+
+	mutex_lock(&data->mutex);
+	if (sysfs_streq(buf, "disable"))
+		status = gpiod_set_pull(desc, GPIOD_PULL_DIS);
+	else if (sysfs_streq(buf, "down"))
+		status = gpiod_set_pull(desc, GPIOD_PULL_DOWN);
+	else if (sysfs_streq(buf, "up"))
+		status = gpiod_set_pull(desc, GPIOD_PULL_UP);
+	else
+		status = -EINVAL;
+	mutex_unlock(&data->mutex);
+
+	return status ? : size;
+}
+static DEVICE_ATTR_WO(pull);
+#endif
+
 static umode_t gpio_is_visible(struct kobject *kobj, struct attribute *attr,
 			       int n)
 {
@@ -377,6 +401,9 @@ static struct attribute *gpio_attrs[] = {
 	&dev_attr_edge.attr,
 	&dev_attr_value.attr,
 	&dev_attr_active_low.attr,
+#ifdef CONFIG_AMLOGIC_PINCTRL
+	&dev_attr_pull.attr,
+#endif
 	NULL,
 };
 

drivers/gpio/gpiolib.c

@@ -2509,6 +2509,26 @@ static void _gpiod_set_raw_value(struct gpio_desc *desc, bool value)
 		chip->set(chip, gpio_chip_hwgpio(desc), value);
 }
 
+#ifdef CONFIG_AMLOGIC_PINCTRL
+static int _gpiod_set_pull(struct gpio_desc *desc, int value)
+{
+	struct gpio_chip *chip;
+	int status = -EINVAL;
+
+	chip = desc->gdev->chip;
+	if (!chip || !chip->set_pull) {
+		gpiod_warn(desc,
+			"%s: missing set_pull() operations\n",
+			__func__);
+		return -EIO;
+	}
+	if (test_bit(FLAG_REQUESTED, &desc->flags))
+		status = chip->set_pull(chip, gpio_chip_hwgpio(desc), value);
+
+	return status;
+}
+#endif
+
 /*
  * set multiple outputs on the same chip;
  * use the chip's set_multiple function if available;
@@ -2631,6 +2651,25 @@ void gpiod_set_value(struct gpio_desc *desc, int value)
 }
 EXPORT_SYMBOL_GPL(gpiod_set_value);
 
+/**
+ * gpiod_set_pull() - enable pull-down/up for the gpio, or disable.
+ * @desc: gpio whose value will be set
+ * @value: value to set
+ *
+ * This function should be called from contexts where we cannot sleep, and will
+ * complain if the GPIO chip functions potentially sleep.
+ */
+#ifdef CONFIG_AMLOGIC_PINCTRL
+int gpiod_set_pull(struct gpio_desc *desc, int value)
+{
+	VALIDATE_DESC(desc);
+	/* Should be using gpiod_set_pull_cansleep() */
+	WARN_ON(desc->gdev->chip->can_sleep);
+	return _gpiod_set_pull(desc, value);
+}
+EXPORT_SYMBOL_GPL(gpiod_set_pull);
+#endif
+
 /**
  * gpiod_set_raw_array_value() - assign values to an array of GPIOs
  * @array_size: number of elements in the descriptor / value arrays
@@ -2888,6 +2927,23 @@ void gpiod_set_value_cansleep(struct gpio_desc *desc, int value)
 }
 EXPORT_SYMBOL_GPL(gpiod_set_value_cansleep);
 
+/**
+ * gpiod_set_pull_cansleep() - enable pull-down/up for the gpio, or disable.
+ * @desc: gpio whose value will be set
+ * @value: value to set
+ *
+ * This function is to be called from contexts that can sleep.
+ */
+#ifdef CONFIG_AMLOGIC_PINCTRL
+int gpiod_set_pull_cansleep(struct gpio_desc *desc, int value)
+{
+	might_sleep_if(extra_checks);
+	VALIDATE_DESC(desc);
+	return _gpiod_set_pull(desc, value);
+}
+EXPORT_SYMBOL_GPL(gpiod_set_pull_cansleep);
+#endif
+
 /**
  * gpiod_set_raw_array_value_cansleep() - assign values to an array of GPIOs
  * @array_size: number of elements in the descriptor / value arrays

include/linux/gpio/consumer.h

@@ -41,6 +41,14 @@ enum gpiod_flags {
 			  GPIOD_FLAGS_BIT_DIR_VAL,
 };
 
+#ifdef CONFIG_AMLOGIC_PINCTRL
+enum gpiod_pull_type {
+	GPIOD_PULL_DIS = 0,
+	GPIOD_PULL_DOWN = 1,
+	GPIOD_PULL_UP = 2,
+};
+#endif
+
 #ifdef CONFIG_GPIOLIB
 
 /* Return the number of GPIOs associated with a device / function */
@@ -100,6 +108,9 @@ int gpiod_direction_output_raw(struct gpio_desc *desc, int value);
 /* Value get/set from non-sleeping context */
 int gpiod_get_value(const struct gpio_desc *desc);
 void gpiod_set_value(struct gpio_desc *desc, int value);
+#ifdef CONFIG_AMLOGIC_PINCTRL
+int gpiod_set_pull(struct gpio_desc *desc, int value);
+#endif
 void gpiod_set_array_value(unsigned int array_size,
 			   struct gpio_desc **desc_array, int *value_array);
 int gpiod_get_raw_value(const struct gpio_desc *desc);
@@ -111,6 +122,9 @@ void gpiod_set_raw_array_value(unsigned int array_size,
 /* Value get/set from sleeping context */
 int gpiod_get_value_cansleep(const struct gpio_desc *desc);
 void gpiod_set_value_cansleep(struct gpio_desc *desc, int value);
+#ifdef CONFIG_AMLOGIC_PINCTRL
+int gpiod_set_pull_scansleep(struct gpio_desc *desc, int value);
+#endif
 void gpiod_set_array_value_cansleep(unsigned int array_size,
 				    struct gpio_desc **desc_array,
 				    int *value_array);
@@ -323,6 +337,15 @@ static inline void gpiod_set_raw_value(struct gpio_desc *desc, int value)
 	/* GPIO can never have been requested */
 	WARN_ON(1);
 }
+
+#ifdef CONFIG_AMLOGIC_PINCTRL
+static inline int gpiod_set_pull(struct gpio_desc *desc, int value)
+{
+	WARN_ON(1);
+	return -EINVAL;
+}
+#endif
+
 static inline void gpiod_set_raw_array_value(unsigned int array_size,
 					     struct gpio_desc **desc_array,
 					     int *value_array)
@@ -342,6 +365,15 @@ static inline void gpiod_set_value_cansleep(struct gpio_desc *desc, int value)
 	/* GPIO can never have been requested */
 	WARN_ON(1);
 }
+
+#ifdef CONFIG_AMLOGIC_PINCTRL
+static inline int gpiod_set_pull_cansleep(struct gpio_desc *desc, int value)
+{
+	WARN_ON(1);
+	return -EINVAL;
+}
+#endif
+
 static inline void gpiod_set_array_value_cansleep(unsigned int array_size,
 					    struct gpio_desc **desc_array,
 					    int *value_array)

include/linux/gpio/driver.h

@@ -58,6 +58,7 @@ enum single_ended_mode {
  *	if a consumer request this. The driver may return -ENOTSUPP if e.g.
  *	it supports just open drain but not open source and is called
  *	with LINE_MODE_OPEN_SOURCE as mode argument.
+ * @set_pull: set the current pull configuration for the GPIO.
  * @to_irq: optional hook supporting non-static gpio_to_irq() mappings;
  *	implementation may not sleep
  * @dbg_show: optional routine to show contents in debugfs; default code
@@ -156,7 +157,10 @@ struct gpio_chip {
 	int			(*set_single_ended)(struct gpio_chip *chip,
 						unsigned offset,
 						enum single_ended_mode mode);
-
+#ifdef CONFIG_AMLOGIC_PINCTRL
+	int			(*set_pull)(struct gpio_chip *chip,
+						unsigned int offset, int value);
+#endif
 	int			(*to_irq)(struct gpio_chip *chip,
 						unsigned offset);