diff options
| -rw-r--r-- | Documentation/gpio/consumer.txt | 33 | ||||
| -rw-r--r-- | drivers/gpio/gpiolib-acpi.c | 84 | ||||
| -rw-r--r-- | drivers/gpio/gpiolib.c | 145 | ||||
| -rw-r--r-- | drivers/gpio/gpiolib.h | 7 | ||||
| -rw-r--r-- | include/linux/gpio/consumer.h | 46 |
5 files changed, 312 insertions, 3 deletions
diff --git a/Documentation/gpio/consumer.txt b/Documentation/gpio/consumer.txt index d85fbae451ea..2924f2ffcd91 100644 --- a/Documentation/gpio/consumer.txt +++ b/Documentation/gpio/consumer.txt @@ -58,7 +58,6 @@ pattern where a GPIO is optional, the gpiod_get_optional() and gpiod_get_index_optional() functions can be used. These functions return NULL instead of -ENOENT if no GPIO has been assigned to the requested function: - struct gpio_desc *gpiod_get_optional(struct device *dev, const char *con_id, enum gpiod_flags flags) @@ -68,6 +67,27 @@ instead of -ENOENT if no GPIO has been assigned to the requested function: unsigned int index, enum gpiod_flags flags) +For a function using multiple GPIOs all of those can be obtained with one call: + + struct gpio_descs *gpiod_get_array(struct device *dev, + const char *con_id, + enum gpiod_flags flags) + +This function returns a struct gpio_descs which contains an array of +descriptors: + + struct gpio_descs { + unsigned int ndescs; + struct gpio_desc *desc[]; + } + +The following function returns NULL instead of -ENOENT if no GPIOs have been +assigned to the requested function: + + struct gpio_descs *gpiod_get_array_optional(struct device *dev, + const char *con_id, + enum gpiod_flags flags) + Device-managed variants of these functions are also defined: struct gpio_desc *devm_gpiod_get(struct device *dev, const char *con_id, @@ -91,8 +111,15 @@ A GPIO descriptor can be disposed of using the gpiod_put() function: void gpiod_put(struct gpio_desc *desc) -It is strictly forbidden to use a descriptor after calling this function. The -device-managed variant is, unsurprisingly: +For an array of GPIOs this function can be used: + + void gpiod_put_array(struct gpio_descs *descs) + +It is strictly forbidden to use a descriptor after calling these functions. +It is also not allowed to individually release descriptors (using gpiod_put()) +from an array acquired with gpiod_get_array(). + +The device-managed variant is, unsurprisingly: void devm_gpiod_put(struct device *dev, struct gpio_desc *desc) diff --git a/drivers/gpio/gpiolib-acpi.c b/drivers/gpio/gpiolib-acpi.c index c0929d938ced..c4919966453d 100644 --- a/drivers/gpio/gpiolib-acpi.c +++ b/drivers/gpio/gpiolib-acpi.c @@ -712,3 +712,87 @@ void acpi_gpiochip_remove(struct gpio_chip *chip) acpi_detach_data(handle, acpi_gpio_chip_dh); kfree(acpi_gpio); } + +static unsigned int acpi_gpio_package_count(const union acpi_object *obj) +{ + const union acpi_object *element = obj->package.elements; + const union acpi_object *end = element + obj->package.count; + unsigned int count = 0; + + while (element < end) { + if (element->type == ACPI_TYPE_LOCAL_REFERENCE) + count++; + + element++; + } + return count; +} + +static int acpi_find_gpio_count(struct acpi_resource *ares, void *data) +{ + unsigned int *count = data; + + if (ares->type == ACPI_RESOURCE_TYPE_GPIO) + *count += ares->data.gpio.pin_table_length; + + return 1; +} + +/** + * acpi_gpio_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 acpi_gpio_count(struct device *dev, const char *con_id) +{ + struct acpi_device *adev = ACPI_COMPANION(dev); + const union acpi_object *obj; + const struct acpi_gpio_mapping *gm; + int count = -ENOENT; + int ret; + char propname[32]; + unsigned int i; + + /* Try first from _DSD */ + for (i = 0; i < ARRAY_SIZE(gpio_suffixes); i++) { + if (con_id && strcmp(con_id, "gpios")) + snprintf(propname, sizeof(propname), "%s-%s", + con_id, gpio_suffixes[i]); + else + snprintf(propname, sizeof(propname), "%s", + gpio_suffixes[i]); + + ret = acpi_dev_get_property(adev, propname, ACPI_TYPE_ANY, + &obj); + if (ret == 0) { + if (obj->type == ACPI_TYPE_LOCAL_REFERENCE) + count = 1; + else if (obj->type == ACPI_TYPE_PACKAGE) + count = acpi_gpio_package_count(obj); + } else if (adev->driver_gpios) { + for (gm = adev->driver_gpios; gm->name; gm++) + if (strcmp(propname, gm->name) == 0) { + count = gm->size; + break; + } + } + if (count >= 0) + break; + } + + /* Then from plain _CRS GPIOs */ + if (count < 0) { + struct list_head resource_list; + unsigned int crs_count = 0; + + INIT_LIST_HEAD(&resource_list); + acpi_dev_get_resources(adev, &resource_list, + acpi_find_gpio_count, &crs_count); + acpi_dev_free_resource_list(&resource_list); + if (crs_count > 0) + count = crs_count; + } + return count; +} 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) diff --git a/drivers/gpio/gpiolib.h b/drivers/gpio/gpiolib.h index 205dd12659c0..54bc5ec91398 100644 --- a/drivers/gpio/gpiolib.h +++ b/drivers/gpio/gpiolib.h @@ -40,6 +40,8 @@ void acpi_gpiochip_free_interrupts(struct gpio_chip *chip); struct gpio_desc *acpi_get_gpiod_by_index(struct acpi_device *adev, const char *propname, int index, struct acpi_gpio_info *info); + +int acpi_gpio_count(struct device *dev, const char *con_id); #else static inline void acpi_gpiochip_add(struct gpio_chip *chip) { } static inline void acpi_gpiochip_remove(struct gpio_chip *chip) { } @@ -56,6 +58,11 @@ acpi_get_gpiod_by_index(struct acpi_device *adev, const char *propname, { return ERR_PTR(-ENOSYS); } + +static inline int acpi_gpio_count(struct device *dev, const char *con_id) +{ + return -ENODEV; +} #endif struct gpio_desc *of_get_named_gpiod_flags(struct device_node *np, diff --git a/include/linux/gpio/consumer.h b/include/linux/gpio/consumer.h index ed20759229eb..33eb52fd0932 100644 --- a/include/linux/gpio/consumer.h +++ b/include/linux/gpio/consumer.h @@ -16,6 +16,15 @@ struct device; */ struct gpio_desc; +/** + * Struct containing an array of descriptors that can be obtained using + * gpiod_get_array(). + */ +struct gpio_descs { + unsigned int ndescs; + struct gpio_desc *desc[]; +}; + #define GPIOD_FLAGS_BIT_DIR_SET BIT(0) #define GPIOD_FLAGS_BIT_DIR_OUT BIT(1) #define GPIOD_FLAGS_BIT_DIR_VAL BIT(2) @@ -34,6 +43,9 @@ enum gpiod_flags { #ifdef CONFIG_GPIOLIB +/* Return the number of GPIOs associated with a device / function */ +int gpiod_count(struct device *dev, const char *con_id); + /* Acquire and dispose GPIOs */ struct gpio_desc *__must_check __gpiod_get(struct device *dev, const char *con_id, @@ -49,7 +61,14 @@ struct gpio_desc *__must_check __gpiod_get_index_optional(struct device *dev, const char *con_id, unsigned int index, enum gpiod_flags flags); +struct gpio_descs *__must_check gpiod_get_array(struct device *dev, + const char *con_id, + enum gpiod_flags flags); +struct gpio_descs *__must_check gpiod_get_array_optional(struct device *dev, + const char *con_id, + enum gpiod_flags flags); void gpiod_put(struct gpio_desc *desc); +void gpiod_put_array(struct gpio_descs *descs); struct gpio_desc *__must_check __devm_gpiod_get(struct device *dev, const char *con_id, @@ -114,6 +133,11 @@ struct gpio_desc *devm_get_gpiod_from_child(struct device *dev, struct fwnode_handle *child); #else /* CONFIG_GPIOLIB */ +static inline int gpiod_count(struct device *dev, const char *con_id) +{ + return 0; +} + static inline struct gpio_desc *__must_check __gpiod_get(struct device *dev, const char *con_id, enum gpiod_flags flags) @@ -143,6 +167,20 @@ __gpiod_get_index_optional(struct device *dev, const char *con_id, return ERR_PTR(-ENOSYS); } +static inline struct gpio_descs *__must_check +gpiod_get_array(struct device *dev, const char *con_id, + enum gpiod_flags flags) +{ + return ERR_PTR(-ENOSYS); +} + +static inline struct gpio_descs *__must_check +gpiod_get_array_optional(struct device *dev, const char *con_id, + enum gpiod_flags flags) +{ + return ERR_PTR(-ENOSYS); +} + static inline void gpiod_put(struct gpio_desc *desc) { might_sleep(); @@ -151,6 +189,14 @@ static inline void gpiod_put(struct gpio_desc *desc) WARN_ON(1); } +static inline void gpiod_put_array(struct gpio_descs *descs) +{ + might_sleep(); + + /* GPIO can never have been requested */ + WARN_ON(1); +} + static inline struct gpio_desc *__must_check __devm_gpiod_get(struct device *dev, const char *con_id, |