diff options
| -rw-r--r-- | Documentation/driver-api/gpio/board.rst | 15 | ||||
| -rw-r--r-- | drivers/gpio/gpiolib.c | 22 | ||||
| -rw-r--r-- | include/linux/gpio/machine.h | 17 |
3 files changed, 37 insertions, 17 deletions
diff --git a/Documentation/driver-api/gpio/board.rst b/Documentation/driver-api/gpio/board.rst index ce91518bf9f4..191fa867826a 100644 --- a/Documentation/driver-api/gpio/board.rst +++ b/Documentation/driver-api/gpio/board.rst @@ -113,13 +113,15 @@ files that desire to do so need to include the following header:: GPIOs are mapped by the means of tables of lookups, containing instances of the gpiod_lookup structure. Two macros are defined to help declaring such mappings:: - GPIO_LOOKUP(chip_label, chip_hwnum, con_id, flags) - GPIO_LOOKUP_IDX(chip_label, chip_hwnum, con_id, idx, flags) + GPIO_LOOKUP(key, chip_hwnum, con_id, flags) + GPIO_LOOKUP_IDX(key, chip_hwnum, con_id, idx, flags) where - - chip_label is the label of the gpiod_chip instance providing the GPIO - - chip_hwnum is the hardware number of the GPIO within the chip + - key is either the label of the gpiod_chip instance providing the GPIO, or + the GPIO line name + - chip_hwnum is the hardware number of the GPIO within the chip, or U16_MAX + to indicate that key is a GPIO line name - con_id is the name of the GPIO function from the device point of view. It can be NULL, in which case it will match any function. - idx is the index of the GPIO within the function. @@ -135,7 +137,10 @@ where In the future, these flags might be extended to support more properties. -Note that GPIO_LOOKUP() is just a shortcut to GPIO_LOOKUP_IDX() where idx = 0. +Note that: + 1. GPIO line names are not guaranteed to be globally unique, so the first + match found will be used. + 2. GPIO_LOOKUP() is just a shortcut to GPIO_LOOKUP_IDX() where idx = 0. A lookup table can then be defined as follows, with an empty entry defining its end. The 'dev_id' field of the table is the identifier of the device that will diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c index 40f2d7f69be2..3c1dcdfe8572 100644 --- a/drivers/gpio/gpiolib.c +++ b/drivers/gpio/gpiolib.c @@ -4618,7 +4618,7 @@ static struct gpio_desc *gpiod_find(struct device *dev, const char *con_id, if (!table) return desc; - for (p = &table->table[0]; p->chip_label; p++) { + for (p = &table->table[0]; p->key; p++) { struct gpio_chip *gc; /* idx must always match exactly */ @@ -4629,18 +4629,30 @@ static struct gpio_desc *gpiod_find(struct device *dev, const char *con_id, if (p->con_id && (!con_id || strcmp(p->con_id, con_id))) continue; - gc = find_chip_by_name(p->chip_label); + if (p->chip_hwnum == U16_MAX) { + desc = gpio_name_to_desc(p->key); + if (desc) { + *flags = p->flags; + return desc; + } + + dev_warn(dev, "cannot find GPIO line %s, deferring\n", + p->key); + return ERR_PTR(-EPROBE_DEFER); + } + + gc = find_chip_by_name(p->key); if (!gc) { /* * As the lookup table indicates a chip with - * p->chip_label should exist, assume it may + * p->key should exist, assume it may * still appear later and let the interested * consumer be probed again or let the Deferred * Probe infrastructure handle the error. */ dev_warn(dev, "cannot find GPIO chip %s, deferring\n", - p->chip_label); + p->key); return ERR_PTR(-EPROBE_DEFER); } @@ -4671,7 +4683,7 @@ static int platform_gpio_count(struct device *dev, const char *con_id) if (!table) return -ENOENT; - for (p = &table->table[0]; p->chip_label; p++) { + for (p = &table->table[0]; p->key; p++) { if ((con_id && p->con_id && !strcmp(con_id, p->con_id)) || (!con_id && !p->con_id)) count++; diff --git a/include/linux/gpio/machine.h b/include/linux/gpio/machine.h index 1ebe5be05d5f..781a053abbb9 100644 --- a/include/linux/gpio/machine.h +++ b/include/linux/gpio/machine.h @@ -20,8 +20,11 @@ enum gpio_lookup_flags { /** * struct gpiod_lookup - lookup table - * @chip_label: name of the chip the GPIO belongs to - * @chip_hwnum: hardware number (i.e. relative to the chip) of the GPIO + * @key: either the name of the chip the GPIO belongs to, or the GPIO line name + * Note that GPIO line names are not guaranteed to be globally unique, + * so this will use the first match found! + * @chip_hwnum: hardware number (i.e. relative to the chip) of the GPIO, or + * U16_MAX to indicate that @key is a GPIO line name * @con_id: name of the GPIO from the device's point of view * @idx: index of the GPIO in case several GPIOs share the same name * @flags: bitmask of gpio_lookup_flags GPIO_* values @@ -30,7 +33,7 @@ enum gpio_lookup_flags { * functions using platform data. */ struct gpiod_lookup { - const char *chip_label; + const char *key; u16 chip_hwnum; const char *con_id; unsigned int idx; @@ -63,17 +66,17 @@ struct gpiod_hog { /* * Simple definition of a single GPIO under a con_id */ -#define GPIO_LOOKUP(_chip_label, _chip_hwnum, _con_id, _flags) \ - GPIO_LOOKUP_IDX(_chip_label, _chip_hwnum, _con_id, 0, _flags) +#define GPIO_LOOKUP(_key, _chip_hwnum, _con_id, _flags) \ + GPIO_LOOKUP_IDX(_key, _chip_hwnum, _con_id, 0, _flags) /* * Use this macro if you need to have several GPIOs under the same con_id. * Each GPIO needs to use a different index and can be accessed using * gpiod_get_index() */ -#define GPIO_LOOKUP_IDX(_chip_label, _chip_hwnum, _con_id, _idx, _flags) \ +#define GPIO_LOOKUP_IDX(_key, _chip_hwnum, _con_id, _idx, _flags) \ { \ - .chip_label = _chip_label, \ + .key = _key, \ .chip_hwnum = _chip_hwnum, \ .con_id = _con_id, \ .idx = _idx, \ |