diff options
Diffstat (limited to 'drivers/gpio/gpiolib.c')
-rw-r--r-- | drivers/gpio/gpiolib.c | 97 |
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 |