gpio: of_get_named_gpio_flags() return -EPROBE_DEFER if GPIO not yet available

of_get_named_gpio_flags() and of_get_named_gpio() return -EPROBE_DEFER if the
respective GPIO is not (yet) available. This is useful if driver's probe()
functions try to get a GPIO whose controller isn't probed yet. Thus, the driver
can be probed again later on.

The function still returns -EINVAL on other errors (parse error or node doesn't
exist). This way, the case of an optional/intentionally missing GPIO is handled
appropriately.

Signed-off-by: Roland Stigge <stigge@antcom.de>
Acked-by: Alexandre Pereira da Silva <aletes.xgr@gmail.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
This commit is contained in:
Roland Stigge 2012-06-28 00:32:14 +02:00 committed by Linus Walleij
parent e935457630
commit 4fbb0022cb

View File

@ -62,7 +62,10 @@ static int of_gpiochip_find_and_xlate(struct gpio_chip *gc, void *data)
int of_get_named_gpio_flags(struct device_node *np, const char *propname,
int index, enum of_gpio_flags *flags)
{
struct gg_data gg_data = { .flags = flags, .out_gpio = -ENODEV };
/* Return -EPROBE_DEFER to support probe() functions to be called
* later when the GPIO actually becomes available
*/
struct gg_data gg_data = { .flags = flags, .out_gpio = -EPROBE_DEFER };
int ret;
/* .of_xlate might decide to not fill in the flags, so clear it. */