From mboxrd@z Thu Jan 1 00:00:00 1970 From: stigge@antcom.de (Roland Stigge) Date: Sun, 17 Jun 2012 12:11:31 +0200 Subject: [PATCH] gpio: of_get_named_gpio_flags() return -EPROBE_DEFER if GPIO not yet available Message-ID: <1339927893-8842-1-git-send-email-stigge@antcom.de> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org 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 --- drivers/gpio/gpiolib-of.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) --- linux-2.6.orig/drivers/gpio/gpiolib-of.c +++ linux-2.6/drivers/gpio/gpiolib-of.c @@ -62,7 +62,10 @@ static int of_gpiochip_find_and_xlate(st 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. */