From b908b53d580c3e9aba81ebe3339c5b7b4fa8031d Mon Sep 17 00:00:00 2001 From: Anton Vorontsov Date: Mon, 1 Dec 2008 06:30:04 +0000 Subject: of/gpio: Implement of_get_gpio_flags() This adds a new function, of_get_gpio_flags, which is like of_get_gpio(), but accepts a new "flags" argument. This new function will be used by the drivers that need to retrieve additional GPIO information, such as active-low flag. Also, this changes the default ("simple") .xlate routine to warn about bogus (< 2) #gpio-cells usage: the second cell should always be present for GPIO flags. Signed-off-by: Anton Vorontsov Signed-off-by: Paul Mackerras --- drivers/of/gpio.c | 36 +++++++++++++++++++++++++++++------- 1 file changed, 29 insertions(+), 7 deletions(-) (limited to 'drivers/of') diff --git a/drivers/of/gpio.c b/drivers/of/gpio.c index 7cd7301b583..a4ba217116e 100644 --- a/drivers/of/gpio.c +++ b/drivers/of/gpio.c @@ -19,14 +19,17 @@ #include /** - * 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 +77,41 @@ 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_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); -- cgit v1.2.3-70-g09d2