Currently there is no way for drivers to request a GPIO on a particular gpio chip. This makes it hard to support multiple GPIO controllers with dynamic GPIO and interrupt numbering, such as with CONFIG_SPARSE_IRQ.
Make it easier for device drivers to find GPIOs on a specific gpio_chip by adding two functions: gpiochip_find_by_name() and gpio_find_by_chip_name(). Note that as gpiochip_find() is already exported, we may as well export gpiochip_find_by_name() too. Cc: Grant Likely <[email protected]> Cc: Linus Walleij <[email protected]> Cc: Arnd Bergmann <[email protected]> Cc: Rajendra Nayak <[email protected]> Signed-off-by: Tony Lindgren <[email protected]> --- drivers/gpio/gpiolib.c | 47 ++++++++++++++++++++++++++++++++++++++++++++ include/asm-generic/gpio.h | 3 ++- 2 files changed, 49 insertions(+), 1 deletions(-) diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c index 17fdf4b..0e5bf55 100644 --- a/drivers/gpio/gpiolib.c +++ b/drivers/gpio/gpiolib.c @@ -1173,6 +1173,53 @@ struct gpio_chip *gpiochip_find(void *data, } EXPORT_SYMBOL_GPL(gpiochip_find); +static int match_name(struct gpio_chip *chip, void *data) +{ + const char *name = data; + + return sysfs_streq(name, chip->label); +} + +/** + * gpiochip_find_by_name() - iterator for locating a gpio_chip by name + * @name: name of the gpio_chip + * + * Similar to bus_find_device_by_name. It returns a reference to the + * first gpio_chip with matching name. It ignores NULL and empty names. + * If you need to do something more complex, then use gpiochip_find. + */ +struct gpio_chip *gpiochip_find_by_name(const char *name) +{ + if (!name || !strcmp(name, "")) + return NULL; + + return gpiochip_find((void *)name, match_name); +} +EXPORT_SYMBOL_GPL(gpiochip_find_by_name); + +/** + * gpio_find_by_chip_name() - find a gpio on a specific gpio_chip + * @chip_name: name of the gpio_chip + * @gpio_offset: offset of the gpio on the gpio_chip + * + * Note that gpiochip_find_by_name returns the first matching + * gpio_chip name. For more complex matching, see gpio_find. + */ +int gpio_find_by_chip_name(const char *chip_name, unsigned gpio_offset) +{ + struct gpio_chip *chip; + int gpio, res; + + chip = gpiochip_find_by_name(chip_name); + if (!chip) + return -ENODEV; + + gpio = chip->base + gpio_offset; + + return gpio; +} +EXPORT_SYMBOL_GPL(gpio_find_by_chip_name); + /* These "optional" allocation calls help prevent drivers from stomping * on each other, and help provide better diagnostics in debugfs. * They're called even less than the "set direction" calls. diff --git a/include/asm-generic/gpio.h b/include/asm-generic/gpio.h index 1ff4e22..d7a2100 100644 --- a/include/asm-generic/gpio.h +++ b/include/asm-generic/gpio.h @@ -145,7 +145,8 @@ extern int __must_check gpiochip_remove(struct gpio_chip *chip); extern struct gpio_chip *gpiochip_find(void *data, int (*match)(struct gpio_chip *chip, void *data)); - +extern struct gpio_chip *gpiochip_find_by_name(const char *name); +extern int gpio_find_by_chip_name(const char *chip_name, unsigned gpio_offset); /* Always use the library code for GPIO management calls, * or when sleeping may be involved. -- To unsubscribe from this list: send the line "unsubscribe linux-mmc" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
