diff options
Diffstat (limited to 'drivers/gpio/gpiolib.c')
| -rw-r--r-- | drivers/gpio/gpiolib.c | 145 |
1 files changed, 145 insertions, 0 deletions
diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c index 2f8296c021e5..3d5b85a7dcdf 100644 --- a/drivers/gpio/gpiolib.c +++ b/drivers/gpio/gpiolib.c @@ -1806,6 +1806,70 @@ static struct gpio_desc *gpiod_find(struct device *dev, const char *con_id, return desc; } +static int dt_gpio_count(struct device *dev, const char *con_id) +{ + int ret; + char propname[32]; + unsigned int i; + + for (i = 0; i < ARRAY_SIZE(gpio_suffixes); i++) { + if (con_id) + snprintf(propname, sizeof(propname), "%s-%s", + con_id, gpio_suffixes[i]); + else + snprintf(propname, sizeof(propname), "%s", + gpio_suffixes[i]); + + ret = of_gpio_named_count(dev->of_node, propname); + if (ret >= 0) + break; + } + return ret; +} + +static int platform_gpio_count(struct device *dev, const char *con_id) +{ + struct gpiod_lookup_table *table; + struct gpiod_lookup *p; + unsigned int count = 0; + + table = gpiod_find_lookup_table(dev); + if (!table) + return -ENOENT; + + for (p = &table->table[0]; p->chip_label; p++) { + if ((con_id && p->con_id && !strcmp(con_id, p->con_id)) || + (!con_id && !p->con_id)) + count++; + } + if (!count) + return -ENOENT; + + return count; +} + +/** + * 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 + * @con_id: function within the GPIO consumer + */ +int gpiod_count(struct device *dev, const char *con_id) +{ + int count = -ENOENT; + + if (IS_ENABLED(CONFIG_OF) && dev && dev->of_node) + count = dt_gpio_count(dev, con_id); + else if (IS_ENABLED(CONFIG_ACPI) && dev && ACPI_HANDLE(dev)) + count = acpi_gpio_count(dev, con_id); + + if (count < 0) + count = platform_gpio_count(dev, con_id); + + return count; +} +EXPORT_SYMBOL_GPL(gpiod_count); + /** * gpiod_get - obtain a GPIO for a given GPIO function * @dev: GPIO consumer, can be NULL for system-global GPIOs @@ -2090,6 +2154,72 @@ static void gpiochip_free_hogs(struct gpio_chip *chip) } /** + * gpiod_get_array - obtain multiple GPIOs from a multi-index GPIO function + * @dev: GPIO consumer, can be NULL for system-global GPIOs + * @con_id: function within the GPIO consumer + * @flags: optional GPIO initialization flags + * + * This function acquires all the GPIOs defined under a given function. + * + * Return a struct gpio_descs containing an array of descriptors, -ENOENT if + * no GPIO has been assigned to the requested function, or another IS_ERR() + * code if an error occurred while trying to acquire the GPIOs. + */ +struct gpio_descs *__must_check gpiod_get_array(struct device *dev, + const char *con_id, + enum gpiod_flags flags) +{ + struct gpio_desc *desc; + struct gpio_descs *descs; + int count; + + count = gpiod_count(dev, con_id); + if (count < 0) + return ERR_PTR(count); + + descs = kzalloc(sizeof(*descs) + sizeof(descs->desc[0]) * count, + GFP_KERNEL); + if (!descs) + return ERR_PTR(-ENOMEM); + + for (descs->ndescs = 0; descs->ndescs < count; ) { + desc = gpiod_get_index(dev, con_id, descs->ndescs, flags); + if (IS_ERR(desc)) { + gpiod_put_array(descs); + return ERR_CAST(desc); + } + descs->desc[descs->ndescs] = desc; + descs->ndescs++; + } + return descs; +} +EXPORT_SYMBOL_GPL(gpiod_get_array); + +/** + * gpiod_get_array_optional - obtain multiple GPIOs from a multi-index GPIO + * function + * @dev: GPIO consumer, can be NULL for system-global GPIOs + * @con_id: function within the GPIO consumer + * @flags: optional GPIO initialization flags + * + * This is equivalent to gpiod_get_array(), except that when no GPIO was + * assigned to the requested function it will return NULL. + */ +struct gpio_descs *__must_check gpiod_get_array_optional(struct device *dev, + const char *con_id, + enum gpiod_flags flags) +{ + struct gpio_descs *descs; + + descs = gpiod_get_array(dev, con_id, flags); + if (IS_ERR(descs) && (PTR_ERR(descs) == -ENOENT)) + return NULL; + + return descs; +} +EXPORT_SYMBOL_GPL(gpiod_get_array_optional); + +/** * gpiod_put - dispose of a GPIO descriptor * @desc: GPIO descriptor to dispose of * @@ -2101,6 +2231,21 @@ void gpiod_put(struct gpio_desc *desc) } EXPORT_SYMBOL_GPL(gpiod_put); +/** + * gpiod_put_array - dispose of multiple GPIO descriptors + * @descs: struct gpio_descs containing an array of descriptors + */ +void gpiod_put_array(struct gpio_descs *descs) +{ + unsigned int i; + + for (i = 0; i < descs->ndescs; i++) + gpiod_put(descs->desc[i]); + + kfree(descs); +} +EXPORT_SYMBOL_GPL(gpiod_put_array); + #ifdef CONFIG_DEBUG_FS static void gpiolib_dbg_show(struct seq_file *s, struct gpio_chip *chip) |