* Grant Likely <grant.likely@xxxxxxxxxxxx> [120308 17:08]: > On Fri, 2 Mar 2012 11:06:15 -0800, Tony Lindgren <tony@xxxxxxxxxxx> wrote: > > > > Want to do that as a separate patch or want me to fold it in? > > I've got it as a separate commit in my gpio/next branch. OK great, below is my patch updated against gpio/next if you want to pick it up. Regards, Tony From: Tony Lindgren <tony@xxxxxxxxxxx> Date: Fri, 2 Mar 2012 11:30:23 -0800 Subject: [PATCH] gpiolib: Add gpiochip_find_by_name() and gpio_find_by_chip_name() Currently there is no way for drivers to request a GPIO on a particular gpio chip using platform data. This makes it hard to support multiple GPIO controllers with platform driver with dynamic GPIO and interrupt numbering, such as with CONFIG_SPARSE_IRQ. Let's make it easier for platform 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 these functions should not be used with device tree as pointed out by Grant Likely <grant.likely@xxxxxxxxxxxx> as the names are instantiated from device tree. As gpiochip_find() is already exported, we may as well export gpiochip_find_by_name() too. Cc: Grant Likely <grant.likely@xxxxxxxxxxxx> Cc: Linus Walleij <linus.walleij@xxxxxxxxxxxxxx> Cc: Arnd Bergmann <arnd@xxxxxxxx> Cc: Rajendra Nayak <rnayak@xxxxxx> Signed-off-by: Tony Lindgren <tony@xxxxxxxxxxx> --- a/drivers/gpio/gpiolib.c +++ b/drivers/gpio/gpiolib.c @@ -1178,6 +1178,51 @@ struct gpio_chip *gpiochip_find(const void *data, } EXPORT_SYMBOL_GPL(gpiochip_find); +static int gpiochip_match_name(struct gpio_chip *chip, const void *name) +{ + return !strcmp(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(name, gpiochip_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; + + 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. --- 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(const void *data, int (*match)(struct gpio_chip *chip, const 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 majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html