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path: root/drivers/gpio/gpiolib.c
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Diffstat (limited to 'drivers/gpio/gpiolib.c')
-rw-r--r--drivers/gpio/gpiolib.c97
1 files changed, 88 insertions, 9 deletions
diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c
index bdbc1649eafa..fb33ff6fc1a9 100644
--- a/drivers/gpio/gpiolib.c
+++ b/drivers/gpio/gpiolib.c
@@ -86,6 +86,7 @@ static int gpiochip_add_irqchip(struct gpio_chip *gpiochip,
struct lock_class_key *lock_key,
struct lock_class_key *request_key);
static void gpiochip_irqchip_remove(struct gpio_chip *gpiochip);
+static int gpiochip_irqchip_init_hw(struct gpio_chip *gpiochip);
static int gpiochip_irqchip_init_valid_mask(struct gpio_chip *gpiochip);
static void gpiochip_irqchip_free_valid_mask(struct gpio_chip *gpiochip);
@@ -1406,6 +1407,10 @@ int gpiochip_add_data_with_key(struct gpio_chip *chip, void *data,
machine_gpiochip_add(chip);
+ ret = gpiochip_irqchip_init_hw(chip);
+ if (ret)
+ goto err_remove_acpi_chip;
+
ret = gpiochip_irqchip_init_valid_mask(chip);
if (ret)
goto err_remove_acpi_chip;
@@ -1622,6 +1627,16 @@ static struct gpio_chip *find_chip_by_name(const char *name)
* The following is irqchip helper code for gpiochips.
*/
+static int gpiochip_irqchip_init_hw(struct gpio_chip *gc)
+{
+ struct gpio_irq_chip *girq = &gc->irq;
+
+ if (!girq->init_hw)
+ return 0;
+
+ return girq->init_hw(gc);
+}
+
static int gpiochip_irqchip_init_valid_mask(struct gpio_chip *gc)
{
struct gpio_irq_chip *girq = &gc->irq;
@@ -2446,8 +2461,13 @@ static inline int gpiochip_add_irqchip(struct gpio_chip *gpiochip,
{
return 0;
}
-
static void gpiochip_irqchip_remove(struct gpio_chip *gpiochip) {}
+
+static inline int gpiochip_irqchip_init_hw(struct gpio_chip *gpiochip)
+{
+ return 0;
+}
+
static inline int gpiochip_irqchip_init_valid_mask(struct gpio_chip *gpiochip)
{
return 0;
@@ -3070,8 +3090,10 @@ int gpiod_direction_output(struct gpio_desc *desc, int value)
if (!ret)
goto set_output_value;
/* Emulate open drain by not actively driving the line high */
- if (value)
- return gpiod_direction_input(desc);
+ if (value) {
+ ret = gpiod_direction_input(desc);
+ goto set_output_flag;
+ }
}
else if (test_bit(FLAG_OPEN_SOURCE, &desc->flags)) {
ret = gpio_set_config(gc, gpio_chip_hwgpio(desc),
@@ -3079,8 +3101,10 @@ int gpiod_direction_output(struct gpio_desc *desc, int value)
if (!ret)
goto set_output_value;
/* Emulate open source by not actively driving the line low */
- if (!value)
- return gpiod_direction_input(desc);
+ if (!value) {
+ ret = gpiod_direction_input(desc);
+ goto set_output_flag;
+ }
} else {
gpio_set_config(gc, gpio_chip_hwgpio(desc),
PIN_CONFIG_DRIVE_PUSH_PULL);
@@ -3088,6 +3112,17 @@ int gpiod_direction_output(struct gpio_desc *desc, int value)
set_output_value:
return gpiod_direction_output_raw_commit(desc, value);
+
+set_output_flag:
+ /*
+ * When emulating open-source or open-drain functionalities by not
+ * actively driving the line (setting mode to input) we still need to
+ * set the IS_OUT flag or otherwise we won't be able to set the line
+ * value anymore.
+ */
+ if (ret == 0)
+ set_bit(FLAG_IS_OUT, &desc->flags);
+ return ret;
}
EXPORT_SYMBOL_GPL(gpiod_direction_output);
@@ -3448,8 +3483,6 @@ static void gpio_set_open_drain_value_commit(struct gpio_desc *desc, bool value)
if (value) {
ret = chip->direction_input(chip, offset);
- if (!ret)
- clear_bit(FLAG_IS_OUT, &desc->flags);
} else {
ret = chip->direction_output(chip, offset, 0);
if (!ret)
@@ -3479,8 +3512,6 @@ static void gpio_set_open_source_value_commit(struct gpio_desc *desc, bool value
set_bit(FLAG_IS_OUT, &desc->flags);
} else {
ret = chip->direction_input(chip, offset);
- if (!ret)
- clear_bit(FLAG_IS_OUT, &desc->flags);
}
trace_gpio_direction(desc_to_gpio(desc), !value, ret);
if (ret < 0)
@@ -4325,6 +4356,54 @@ static int platform_gpio_count(struct device *dev, const char *con_id)
}
/**
+ * fwnode_gpiod_get_index - obtain a GPIO from firmware node
+ * @fwnode: handle of the firmware node
+ * @con_id: function within the GPIO consumer
+ * @index: index of the GPIO to obtain for the consumer
+ * @flags: GPIO initialization flags
+ * @label: label to attach to the requested GPIO
+ *
+ * This function can be used for drivers that get their configuration
+ * from opaque firmware.
+ *
+ * The function properly finds the corresponding GPIO using whatever is the
+ * underlying firmware interface and then makes sure that the GPIO
+ * descriptor is requested before it is returned to the caller.
+ *
+ * Returns:
+ * On successful request the GPIO pin is configured in accordance with
+ * provided @flags.
+ *
+ * In case of error an ERR_PTR() is returned.
+ */
+struct gpio_desc *fwnode_gpiod_get_index(struct fwnode_handle *fwnode,
+ const char *con_id, int index,
+ enum gpiod_flags flags,
+ const char *label)
+{
+ struct gpio_desc *desc;
+ char prop_name[32]; /* 32 is max size of property name */
+ unsigned int i;
+
+ for (i = 0; i < ARRAY_SIZE(gpio_suffixes); i++) {
+ if (con_id)
+ snprintf(prop_name, sizeof(prop_name), "%s-%s",
+ con_id, gpio_suffixes[i]);
+ else
+ snprintf(prop_name, sizeof(prop_name), "%s",
+ gpio_suffixes[i]);
+
+ desc = fwnode_get_named_gpiod(fwnode, prop_name, index, flags,
+ label);
+ if (!IS_ERR(desc) || (PTR_ERR(desc) != -ENOENT))
+ break;
+ }
+
+ return desc;
+}
+EXPORT_SYMBOL_GPL(fwnode_gpiod_get_index);
+
+/**
* gpiod_count - return the number of GPIOs associated with a device / function
* or -ENOENT if no GPIO has been assigned to the requested function
* @dev: GPIO consumer, can be NULL for system-global GPIOs