diff options
Diffstat (limited to 'drivers/of/gpio.c')
| -rw-r--r-- | drivers/of/gpio.c | 70 |
1 files changed, 63 insertions, 7 deletions
diff --git a/drivers/of/gpio.c b/drivers/of/gpio.c index 7cd7301b583..6eea601a920 100644 --- a/drivers/of/gpio.c +++ b/drivers/of/gpio.c @@ -19,14 +19,17 @@ #include <asm/prom.h> /** - * of_get_gpio - Get a GPIO number from the device tree to use with GPIO API + * of_get_gpio_flags - Get a GPIO number and flags to use with GPIO API * @np: device node to get GPIO from * @index: index of the GPIO + * @flags: a flags pointer to fill in * * Returns GPIO number to use with Linux generic GPIO API, or one of the errno - * value on the error condition. + * value on the error condition. If @flags is not NULL the function also fills + * in flags for the GPIO. */ -int of_get_gpio(struct device_node *np, int index) +int of_get_gpio_flags(struct device_node *np, int index, + enum of_gpio_flags *flags) { int ret; struct device_node *gc; @@ -59,7 +62,11 @@ int of_get_gpio(struct device_node *np, int index) goto err1; } - ret = of_gc->xlate(of_gc, np, gpio_spec); + /* .xlate might decide to not fill in the flags, so clear it. */ + if (flags) + *flags = 0; + + ret = of_gc->xlate(of_gc, np, gpio_spec, flags); if (ret < 0) goto err1; @@ -70,26 +77,75 @@ err0: pr_debug("%s exited with status %d\n", __func__, ret); return ret; } -EXPORT_SYMBOL(of_get_gpio); +EXPORT_SYMBOL(of_get_gpio_flags); /** - * of_gpio_simple_xlate - translate gpio_spec to the GPIO number + * of_gpio_count - Count GPIOs for a device + * @np: device node to count GPIOs for + * + * The function returns the count of GPIOs specified for a node. + * + * Note that the empty GPIO specifiers counts too. For example, + * + * gpios = <0 + * &pio1 1 2 + * 0 + * &pio2 3 4>; + * + * defines four GPIOs (so this function will return 4), two of which + * are not specified. + */ +unsigned int of_gpio_count(struct device_node *np) +{ + unsigned int cnt = 0; + + do { + int ret; + + ret = of_parse_phandles_with_args(np, "gpios", "#gpio-cells", + cnt, NULL, NULL); + /* A hole in the gpios = <> counts anyway. */ + if (ret < 0 && ret != -EEXIST) + break; + } while (++cnt); + + return cnt; +} +EXPORT_SYMBOL(of_gpio_count); + +/** + * of_gpio_simple_xlate - translate gpio_spec to the GPIO number and flags * @of_gc: pointer to the of_gpio_chip structure * @np: device node of the GPIO chip * @gpio_spec: gpio specifier as found in the device tree + * @flags: a flags pointer to fill in * * This is simple translation function, suitable for the most 1:1 mapped * gpio chips. This function performs only one sanity check: whether gpio * is less than ngpios (that is specified in the gpio_chip). */ int of_gpio_simple_xlate(struct of_gpio_chip *of_gc, struct device_node *np, - const void *gpio_spec) + const void *gpio_spec, enum of_gpio_flags *flags) { const u32 *gpio = gpio_spec; + /* + * We're discouraging gpio_cells < 2, since that way you'll have to + * write your own xlate function (that will have to retrive the GPIO + * number and the flags from a single gpio cell -- this is possible, + * but not recommended). + */ + if (of_gc->gpio_cells < 2) { + WARN_ON(1); + return -EINVAL; + } + if (*gpio > of_gc->gc.ngpio) return -EINVAL; + if (flags) + *flags = gpio[1]; + return *gpio; } EXPORT_SYMBOL(of_gpio_simple_xlate); |