From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-8.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,USER_AGENT_SANE_1 autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 3C62CC433FF for ; Tue, 13 Aug 2019 05:38:46 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 10BE420673 for ; Tue, 13 Aug 2019 05:38:46 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726500AbfHMFip (ORCPT ); Tue, 13 Aug 2019 01:38:45 -0400 Received: from mout.kundenserver.de ([212.227.17.13]:52263 "EHLO mout.kundenserver.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725820AbfHMFio (ORCPT ); Tue, 13 Aug 2019 01:38:44 -0400 Received: from [192.168.178.60] ([109.104.47.130]) by mrelayeu.kundenserver.de (mreue108 [212.227.15.183]) with ESMTPSA (Nemesis) id 1MQMqN-1hbdV81Pf7-00MN08; Tue, 13 Aug 2019 07:38:39 +0200 Subject: Re: [PATCH v2] gpiolib: Take MUX usage into account To: Ramon Fried , linus.walleij@linaro.org, bgolaszewski@baylibre.com Cc: linux-gpio@vger.kernel.org, linux-kernel@vger.kernel.org References: <20190813014210.15519-1-ramon.fried@linux.intel.com> Reply-To: Stefan Wahren From: Stefan Wahren Message-ID: <1650c967-5176-70db-ff9a-b2af432ba1e7@i2se.com> Date: Tue, 13 Aug 2019 07:38:38 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.8.0 MIME-Version: 1.0 In-Reply-To: <20190813014210.15519-1-ramon.fried@linux.intel.com> Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit Content-Language: en-US X-Provags-ID: V03:K1:GlqnZkg1THBOLCVRM66b8COLiBJs9tJmHP25dZDrzPLL21FgkSe Kq3JPQBjXnsC8Vh5lcJaiXH5I3tIUTGH4fTzp63TaLYai9KXtCMwXaPJJiBgU8AuyBBaOd7 X1SxeahtrTpUKmIYF33SvNgMNktBS/bFOAorKvtKNZfiX/eUy3kTk5AZ4Ek1wPcQrAI/DdV sz9KobSbAYC1ikrSTHJow== X-UI-Out-Filterresults: notjunk:1;V03:K0:930VAuWktZc=:o+zK9PAtwUdR4khEreCpfB gTKpmJwr+iJaUn8tsG2/qUpKE47sRKRJ+2OXgjxbtfhXalN8Usl52qJX0Zsj0bA3xIHzmcpfl kFQlkP/vjf3ino5WyY7jEP4LHhuDYFiIGt7kTi2fsxweDYrEq4UtFeSAg8Jf/MPWIMFGsheVk 84Z7TbR4Nk8Jj3Dqd+JnMw9imA9E01KyyBTMbM2ZiTOjP8HA3Edebej2zcJSnWBtMUc6Bk88Y VYPkWqH1375a14rwQ/YhS4i1J+ghSBBp7xWBLGrMd9IfS5I8yT1rn7xZSmDl27Ns9OPQV1+TD eNK6Ojaz4PGxBkodNUA/p7nG2TVqgeGIY5PDbNg08zULjz2jCGBEv+3D+ku4w0c6k4DjlARQ3 ar1UK16rieFyNFOLgzKElK7KEgJCMOtF5gPWSbnPID0nNpD2amK4EA0QPFzAHBixcZ0ubOZZu XYjyUYs0rs8LLWXNKHq0+kZFYl6EFBqvBsTgWqHNYPh6qNA3a/0+YrklTVT06HNUZ+WAcxgyj 0nXtsiUrBzPMbnIwccoiY+H5sGGI4BfDC0luIbODiN12IL4A7Qre/WW8dd/x0g5oSUulULz3v 1rBwyP5F86gTaK1XzHGdard1Wxxi9EIE6AGU/eL0nN2XWMaeW1R5VF31RuHnqndHKXY7mv8iR UFuX9jDHT670wG4LieY6mTF6QSDOsrr4q7sR+G9cwOwRCbyD/ywKon2CL4R4RtWTPqZTYIPF8 novDlwyQDPghUmkIfIGrxpdRD9fbDE4xuiQg92JhNO5Q8zEnzdeSWRkAWnY= Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Ramon, On 13.08.19 03:42, Ramon Fried wrote: > From: Stefan Wahren > > The user space like gpioinfo only see the GPIO usage but not the > MUX usage (e.g. I2C or SPI usage) of a pin. As a user we want to know which > pin is free/safe to use. So take the MUX usage of strict pinmux controllers > into account to get a more realistic view for ioctl GPIO_GET_LINEINFO_IOCTL. > > Signed-off-by: Stefan Wahren > Tested-by: Ramon Fried > Signed-off-by: Ramon Fried > --- > v2: Address review from linus: > * ** Please notive logic was reversed ** > * renamed pinctrl_gpio_is_in_use() to pinctrl_gpio_can_use_line() > * renamed pinmux_is_in_use() to pinmux_can_be_used_for_gpio() > * changed dev_err to dev_dbg (Linus suggested removing it altogether, I > find it better to keep it for debug). thanks for taking care of this. > > drivers/gpio/gpiolib.c | 3 ++- > drivers/pinctrl/core.c | 28 ++++++++++++++++++++++++++++ > drivers/pinctrl/pinmux.c | 27 +++++++++++++++++++++++++++ > drivers/pinctrl/pinmux.h | 8 ++++++++ > include/linux/pinctrl/consumer.h | 6 ++++++ > 5 files changed, 71 insertions(+), 1 deletion(-) > > diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c > index f497003f119c..52937bf8e514 100644 > --- a/drivers/gpio/gpiolib.c > +++ b/drivers/gpio/gpiolib.c > @@ -1084,7 +1084,8 @@ static long gpio_ioctl(struct file *filp, unsigned int cmd, unsigned long arg) > test_bit(FLAG_IS_HOGGED, &desc->flags) || > test_bit(FLAG_USED_AS_IRQ, &desc->flags) || > test_bit(FLAG_EXPORT, &desc->flags) || > - test_bit(FLAG_SYSFS, &desc->flags)) > + test_bit(FLAG_SYSFS, &desc->flags) || > + !pinctrl_gpio_can_use_line(chip->base + lineinfo.line_offset)) > lineinfo.flags |= GPIOLINE_FLAG_KERNEL; > if (test_bit(FLAG_IS_OUT, &desc->flags)) > lineinfo.flags |= GPIOLINE_FLAG_IS_OUT; > diff --git a/drivers/pinctrl/core.c b/drivers/pinctrl/core.c > index b70df27874d1..2bbd8ee93507 100644 > --- a/drivers/pinctrl/core.c > +++ b/drivers/pinctrl/core.c > @@ -736,6 +736,34 @@ int pinctrl_get_group_selector(struct pinctrl_dev *pctldev, > return -EINVAL; > } > > +bool pinctrl_gpio_can_use_line(unsigned gpio) > +{ > + struct pinctrl_dev *pctldev; > + struct pinctrl_gpio_range *range; > + bool result; > + int pin; > + > + /* > + * Try to obtain GPIO range, if it fails > + * we're probably dealing with GPIO driver > + * without a backing pin controller - bail out. > + */ > + if (pinctrl_get_device_gpio_range(gpio, &pctldev, &range)) > + return true; > + > + mutex_lock(&pctldev->mutex); > + > + /* Convert to the pin controllers number space */ > + pin = gpio_to_pin(range, gpio); > + > + result = pinmux_can_be_used_for_gpio(pctldev, pin); > + > + mutex_unlock(&pctldev->mutex); > + > + return result; > +} > +EXPORT_SYMBOL_GPL(pinctrl_gpio_can_use_line); > + > /** > * pinctrl_gpio_request() - request a single pin to be used as GPIO > * @gpio: the GPIO pin number from the GPIO subsystem number space > diff --git a/drivers/pinctrl/pinmux.c b/drivers/pinctrl/pinmux.c > index 020e54f843f9..7e42a5738d82 100644 > --- a/drivers/pinctrl/pinmux.c > +++ b/drivers/pinctrl/pinmux.c > @@ -70,6 +70,33 @@ int pinmux_validate_map(const struct pinctrl_map *map, int i) > return 0; > } > > +/** > + * pinmux_can_be_used_for_gpio() - check if a specific pin > + * is either muxed to a different function or used as gpio. > + * > + * @pin: the pin number in the global pin space > + * > + * Controllers not defined as strict will always return true, > + * menaning that the gpio can be used. > + */ > +bool pinmux_can_be_used_for_gpio(struct pinctrl_dev *pctldev, unsigned pin) > +{ > + struct pin_desc *desc = pin_desc_get(pctldev, pin); > + const struct pinmux_ops *ops = pctldev->desc->pmxops; > + > + if (!desc) { > + dev_dbg(pctldev->dev, > + "pin %u is not registered so it cannot be requested\n", > + pin); > + return true; This return value looks strange to me. Stefan