* Re: [periperi] How to set default GPIO pin ? [not found] <8738cc0vx9.wl%kuninori.morimoto.gx@gmail.com> @ 2014-09-10 8:55 ` Laurent Pinchart 2014-09-12 7:27 ` Kuninori Morimoto 2014-09-23 15:06 ` Linus Walleij 0 siblings, 2 replies; 6+ messages in thread From: Laurent Pinchart @ 2014-09-10 8:55 UTC (permalink / raw) To: linux-arm-kernel Hi Morimoto-san, (Moving this thread to linux-sh and linux-arm and CC'ing Linus Walleij) On Sunday 31 August 2014 22:08:52 Kuninori Morimoto wrote: > > I know we can use "defalt" PFC settings on DT. > But, how to use "defalt" GPIO pin settings on DT ? > > We would like to use GPIO 7-17 as Low output, > and do nothing after boot. From a DT point of view I believe this is supposed to be done by specifying the output-low or output-high properties in the pinctrl configuration node. However, these properties are not supported by the PFC driver, and there's no easy way for the PFC driver to configure GPIOs handled by a different driver such as the gpio-rcar driver for instance. Linus, do you have any hindsight on how this should be implemented ? -- Regards, Laurent Pinchart ^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [periperi] How to set default GPIO pin ? 2014-09-10 8:55 ` [periperi] How to set default GPIO pin ? Laurent Pinchart @ 2014-09-12 7:27 ` Kuninori Morimoto 2014-09-23 15:06 ` Linus Walleij 1 sibling, 0 replies; 6+ messages in thread From: Kuninori Morimoto @ 2014-09-12 7:27 UTC (permalink / raw) To: linux-arm-kernel Hi Laurent, Linus (Walleij) Thank you for your help > (Moving this thread to linux-sh and linux-arm and CC'ing Linus Walleij) > > On Sunday 31 August 2014 22:08:52 Kuninori Morimoto wrote: > > > > I know we can use "defalt" PFC settings on DT. > > But, how to use "defalt" GPIO pin settings on DT ? > > > > We would like to use GPIO 7-17 as Low output, > > and do nothing after boot. > > From a DT point of view I believe this is supposed to be done by specifying > the output-low or output-high properties in the pinctrl configuration node. > However, these properties are not supported by the PFC driver, and there's no > easy way for the PFC driver to configure GPIOs handled by a different driver > such as the gpio-rcar driver for instance. > > Linus, do you have any hindsight on how this should be implemented ? I'm happy if we can use this "defalt" GPIO on DT. Linus, we need your opinion Best regards --- Kuninori Morimoto ^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [periperi] How to set default GPIO pin ? 2014-09-10 8:55 ` [periperi] How to set default GPIO pin ? Laurent Pinchart 2014-09-12 7:27 ` Kuninori Morimoto @ 2014-09-23 15:06 ` Linus Walleij 2014-09-28 21:25 ` Laurent Pinchart 1 sibling, 1 reply; 6+ messages in thread From: Linus Walleij @ 2014-09-23 15:06 UTC (permalink / raw) To: linux-arm-kernel On Wed, Sep 10, 2014 at 10:55 AM, Laurent Pinchart <laurent.pinchart@ideasonboard.com> wrote: > On Sunday 31 August 2014 22:08:52 Kuninori Morimoto wrote: >> >> I know we can use "defalt" PFC settings on DT. >> But, how to use "defalt" GPIO pin settings on DT ? >> >> We would like to use GPIO 7-17 as Low output, >> and do nothing after boot. > > From a DT point of view I believe this is supposed to be done by specifying > the output-low or output-high properties in the pinctrl configuration node. > However, these properties are not supported by the PFC driver, and there's no > easy way for the PFC driver to configure GPIOs handled by a different driver > such as the gpio-rcar driver for instance. > > Linus, do you have any hindsight on how this should be implemented ? I have suggested adding GPIO hogs, so that a GPIO node can specify that some GPIO's specified on the local ship be hogged high or low at probe. Generic DT bindings and generic code in gpiolib.c. gpios-hog-high = <....>; gpios-hog-low = <....>; Yours, Linus Walleij ^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [periperi] How to set default GPIO pin ? 2014-09-23 15:06 ` Linus Walleij @ 2014-09-28 21:25 ` Laurent Pinchart 2014-09-28 23:58 ` Kuninori Morimoto 2014-09-29 8:58 ` Linus Walleij 0 siblings, 2 replies; 6+ messages in thread From: Laurent Pinchart @ 2014-09-28 21:25 UTC (permalink / raw) To: linux-arm-kernel Hi Linus and Morimoto-san, On Tuesday 23 September 2014 17:06:28 Linus Walleij wrote: > On Wed, Sep 10, 2014 at 10:55 AM, Laurent Pinchart wrote: > > On Sunday 31 August 2014 22:08:52 Kuninori Morimoto wrote: > >> I know we can use "defalt" PFC settings on DT. > >> But, how to use "defalt" GPIO pin settings on DT ? > >> > >> We would like to use GPIO 7-17 as Low output, > >> and do nothing after boot. > > > > From a DT point of view I believe this is supposed to be done by > > specifying the output-low or output-high properties in the pinctrl > > configuration node. However, these properties are not supported by the PFC > > driver, and there's no easy way for the PFC driver to configure GPIOs > > handled by a different driver such as the gpio-rcar driver for instance. > > > > Linus, do you have any hindsight on how this should be implemented ? > > I have suggested adding GPIO hogs, so that a GPIO node can specify > that some GPIO's specified on the local ship be hogged high or > low at probe. Generic DT bindings and generic code in gpiolib.c. > > gpios-hog-high = <....>; > gpios-hog-low = <....>; How about just a gpios-hog property, with a list of gpio specifiers + flags ? That's bikeshedding I suppose. Morimoto-san, would you like to implement that ? :-) -- Regards, Laurent Pinchart ^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [periperi] How to set default GPIO pin ? 2014-09-28 21:25 ` Laurent Pinchart @ 2014-09-28 23:58 ` Kuninori Morimoto 2014-09-29 8:58 ` Linus Walleij 1 sibling, 0 replies; 6+ messages in thread From: Kuninori Morimoto @ 2014-09-28 23:58 UTC (permalink / raw) To: linux-arm-kernel Hi Laurent, Linus > > I have suggested adding GPIO hogs, so that a GPIO node can specify > > that some GPIO's specified on the local ship be hogged high or > > low at probe. Generic DT bindings and generic code in gpiolib.c. > > > > gpios-hog-high = <....>; > > gpios-hog-low = <....>; > > How about just a gpios-hog property, with a list of gpio specifiers + flags ? > That's bikeshedding I suppose. > > Morimoto-san, would you like to implement that ? :-) Thank you for your help OK, I try to implement this method (when I have time :) Thank you Best regards --- Kuninori Morimoto ^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [periperi] How to set default GPIO pin ? 2014-09-28 21:25 ` Laurent Pinchart 2014-09-28 23:58 ` Kuninori Morimoto @ 2014-09-29 8:58 ` Linus Walleij 1 sibling, 0 replies; 6+ messages in thread From: Linus Walleij @ 2014-09-29 8:58 UTC (permalink / raw) To: linux-arm-kernel On Sun, Sep 28, 2014 at 11:25 PM, Laurent Pinchart <laurent.pinchart@ideasonboard.com> wrote: > Hi Linus and Morimoto-san, > > On Tuesday 23 September 2014 17:06:28 Linus Walleij wrote: >> On Wed, Sep 10, 2014 at 10:55 AM, Laurent Pinchart wrote: >> > On Sunday 31 August 2014 22:08:52 Kuninori Morimoto wrote: >> >> I know we can use "defalt" PFC settings on DT. >> >> But, how to use "defalt" GPIO pin settings on DT ? >> >> >> >> We would like to use GPIO 7-17 as Low output, >> >> and do nothing after boot. >> > >> > From a DT point of view I believe this is supposed to be done by >> > specifying the output-low or output-high properties in the pinctrl >> > configuration node. However, these properties are not supported by the PFC >> > driver, and there's no easy way for the PFC driver to configure GPIOs >> > handled by a different driver such as the gpio-rcar driver for instance. >> > >> > Linus, do you have any hindsight on how this should be implemented ? >> >> I have suggested adding GPIO hogs, so that a GPIO node can specify >> that some GPIO's specified on the local ship be hogged high or >> low at probe. Generic DT bindings and generic code in gpiolib.c. >> >> gpios-hog-high = <....>; >> gpios-hog-low = <....>; > > How about just a gpios-hog property, with a list of gpio specifiers + flags ? > That's bikeshedding I suppose. > > Morimoto-san, would you like to implement that ? :-) There was a proposed implementation from Boris BREZILLON, but I was unhappy with parts of it, however check it and see my comments on the patch set: "[RFC PATCH] gpio: add GPIO hogging mechanism" Yours, Linus Walleij ^ permalink raw reply [flat|nested] 6+ messages in thread
end of thread, other threads:[~2014-09-29 8:58 UTC | newest]
Thread overview: 6+ messages (download: mbox.gz follow: Atom feed
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[not found] <8738cc0vx9.wl%kuninori.morimoto.gx@gmail.com>
2014-09-10 8:55 ` [periperi] How to set default GPIO pin ? Laurent Pinchart
2014-09-12 7:27 ` Kuninori Morimoto
2014-09-23 15:06 ` Linus Walleij
2014-09-28 21:25 ` Laurent Pinchart
2014-09-28 23:58 ` Kuninori Morimoto
2014-09-29 8:58 ` Linus Walleij
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