From mboxrd@z Thu Jan 1 00:00:00 1970 From: Shawn Guo Subject: Re: [PATCH] ARM: dts: imx28: add gpio-ranges for internal gpio controller Date: Fri, 12 May 2017 11:05:38 +0800 Message-ID: <20170512030536.GC8471@dragon> References: <20170508085925.18342-1-u.kleine-koenig@pengutronix.de> <20170511075135.GF5833@dragon> <20170511080916.gim5pyhj5jarzf4r@pengutronix.de> Mime-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Transfer-Encoding: 8bit Return-path: Received: from mail.kernel.org ([198.145.29.99]:49932 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750708AbdELDFx (ORCPT ); Thu, 11 May 2017 23:05:53 -0400 Content-Disposition: inline In-Reply-To: <20170511080916.gim5pyhj5jarzf4r@pengutronix.de> Sender: linux-gpio-owner@vger.kernel.org List-Id: linux-gpio@vger.kernel.org To: Uwe =?iso-8859-1?Q?Kleine-K=F6nig?= Cc: Fabio Estevam , linux-gpio@vger.kernel.org, Linus Walleij , kernel@pengutronix.de, linux-arm-kernel@lists.infradead.org On Thu, May 11, 2017 at 10:09:16AM +0200, Uwe Kleine-König wrote: > On Thu, May 11, 2017 at 03:51:36PM +0800, Shawn Guo wrote: > > On Mon, May 08, 2017 at 10:59:25AM +0200, Uwe Kleine-König wrote: > > > Signed-off-by: Uwe Kleine-König > > > --- > > > Hello, > > > > > > with this patch applied I get the following lines in dmesg which looks > > > fine: > > > > > > [ 0.227913] gpio gpiochip0: (80018000.pinctrl:gpio@0): created GPIO range 0->31 ==> 80018000.pinctrl PIN 0->31 > > > [ 0.236100] gpio gpiochip1: (80018000.pinctrl:gpio@1): created GPIO range 0->31 ==> 80018000.pinctrl PIN 32->63 > > > [ 0.244463] gpio gpiochip2: (80018000.pinctrl:gpio@2): created GPIO range 0->31 ==> 80018000.pinctrl PIN 64->95 > > > [ 0.253020] gpio gpiochip3: (80018000.pinctrl:gpio@3): created GPIO range 0->31 ==> 80018000.pinctrl PIN 96->127 > > > [ 0.261639] gpio gpiochip4: (80018000.pinctrl:gpio@4): created GPIO range 0->31 ==> 80018000.pinctrl PIN 128->159 > > > > > > But when looking at a used gpio > > > > > > # cat /sys/kernel/debug/gpio > > > gpiochip0: GPIOs 0-31, parent: platform/80018000.pinctrl:gpio@0, 80018000.pinctrl:gpio@0: > > > ... > > > gpio-20 (LED4 |? ) out hi > > > ... > > > > > > # grep "pin 20 " /sys/kernel/debug/pinctrl/80018000.pinctrl/pinmux-pins > > > pin 20 (GPMI_RDY0): leds (GPIO UNCLAIMED) function leds group leds.0 > > > > > > I wonder why there is still "GPIO UNCLAIMED". I would have expected that > > > this disappears and somehow references the gpio_request issued by the > > > led-gpio driver after my patch. > > > > > > What am I missing? > > > > It seems that's only the case where @strict of struct pinmux_ops is > > true. We should set it true for pinctrl-mxs, I guess? > > The description is: > > * @strict: do not allow simultaneous use of the same pin for GPIO and another > * function. Check both gpio_owner and mux_owner strictly before approving > * the pin request. Sorry, I misread the 'strict' code and my comment about it is completely a noise. I went through the code around requesting a pin, and found that we need to call pinctrl_request_gpio() from gpio driver to get the result you want. In that case, pin_request() will be called with a valid gpio_range as below. pinctrl_request_gpio() pinmux_request_gpio() pin_request(..., gpio_range) Right now, pin_request() is being called with a NULL gpio_range from pinmux_enable_setting(). That gets us the mux_owner rather than gpio_owner for the pin. Shawn