[PATCH v8] reset: Add driver for gpio-controlled reset pins
p.zabel at pengutronix.de
Tue Jul 16 05:51:19 EDT 2013
Am Dienstag, den 16.07.2013, 14:51 +0800 schrieb 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.
Looks good to me. I can squash it into the original patch and resend if
> 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)
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