[PATCH v8] reset: Add driver for gpio-controlled reset pins

[Shawn Guo]

On Tue, Jul 16, 2013 at 09:50:42AM +0800, Shawn Guo wrote:
> Hi Philipp,
> 
> On Thu, May 30, 2013 at 11:09:00AM +0200, Philipp Zabel wrote:
> > This driver implements a reset controller device that toggle a gpio
> > connected to a reset pin of a peripheral IC. The delay between assertion
> > and de-assertion of the reset signal can be configured via device tree.
> > 
> > Signed-off-by: Philipp Zabel <p.zabel at pengutronix.de>
> > Reviewed-by: Stephen Warren <swarren at nvidia.com>
> 
> I see this patch is very useful, as GPIOs are widely used to reset
> components/devices on board.  But I do not find the patch in v3.11-rc1.
> What's your plan about it?
> 
> Also, I'm wondering if we should register the driver a little bit
> early.  Please see the following patch.  If it makes sense to you,
> I can send the patch to you, or you can just quash it into yours.

And here is another change request.

Shawn

----8<---------------

>From 822a0c4fb7c99b371844ba7e957affcaa8cb1cfe Mon Sep 17 00:00:00 2001
From: Shawn Guo <shawn.guo at linaro.org>
Date: Sun, 14 Jul 2013 20:28:05 +0800
Subject: [PATCH] ENGR00269945: reset: handle cansleep case in gpio-reset

Some gpio reset may be backed by a gpio that can sleep, e.g. pca953x
gpio output.  For such gpio, gpio_set_value_cansleep() should be
called.  Otherwise, the WARN_ON(chip->can_sleep) in gpiod_set_value()
will be hit.  Add a gpio_cansleep() check to handle cansleep gpio.

Signed-off-by: Shawn Guo <shawn.guo at linaro.org>
---
 drivers/reset/gpio-reset.c |    5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/drivers/reset/gpio-reset.c b/drivers/reset/gpio-reset.c
index 5d2515a..4f372f9 100644
--- a/drivers/reset/gpio-reset.c
+++ b/drivers/reset/gpio-reset.c
@@ -32,7 +32,10 @@ static void gpio_reset_set(struct reset_controller_dev *rcdev, int asserted)
 	if (drvdata->active_low)
 		value = !value;
 
-	gpio_set_value(drvdata->gpio, value);
+	if (gpio_cansleep(drvdata->gpio))
+		gpio_set_value_cansleep(drvdata->gpio, value);
+	else
+		gpio_set_value(drvdata->gpio, value);
 }
 
 static int gpio_reset(struct reset_controller_dev *rcdev, unsigned long id)
-- 
1.7.9.5