All of lore.kernel.org
 help / color / mirror / Atom feed
* [PATCH RESEND] gpio: of_get_named_gpio_flags() return -EPROBE_DEFER if GPIO not yet available
@ 2012-06-27 22:32 ` Roland Stigge
  0 siblings, 0 replies; 17+ messages in thread
From: Roland Stigge @ 2012-06-27 22:32 UTC (permalink / raw)
  To: cjb, grant.likely, rob.herring, rmk+kernel, ulf.hansson,
	linus.walleij, linux-mmc, linux-kernel, aletes.xgr,
	linux-arm-kernel
  Cc: Roland Stigge

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: Linus Walleij <linus.walleij@linaro.org>

---
Applies to v3.5-rc4

 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. */

^ permalink raw reply	[flat|nested] 17+ messages in thread

end of thread, other threads:[~2012-07-17 18:30 UTC | newest]

Thread overview: 17+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2012-06-27 22:32 [PATCH RESEND] gpio: of_get_named_gpio_flags() return -EPROBE_DEFER if GPIO not yet available Roland Stigge
2012-06-27 22:32 ` Roland Stigge
2012-07-14 19:57 ` Linus Walleij
2012-07-14 19:57   ` Linus Walleij
2012-07-15 21:11   ` Mark Brown
2012-07-15 21:11     ` Mark Brown
2012-07-16 22:16     ` Linus Walleij
2012-07-16 22:16       ` Linus Walleij
2012-07-17  7:43       ` Mark Brown
2012-07-17  7:43         ` Mark Brown
2012-07-17  7:43         ` Mark Brown
2012-07-17 18:17         ` Linus Walleij
2012-07-17 18:17           ` Linus Walleij
2012-07-17 18:24 ` Linus Walleij
2012-07-17 18:24   ` Linus Walleij
2012-07-17 18:30   ` Alexandre Pereira da Silva
2012-07-17 18:30     ` Alexandre Pereira da Silva

This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.