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=ham 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 246C4C433FF for ; Tue, 13 Aug 2019 06:10:46 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id F1E5F20679 for ; Tue, 13 Aug 2019 06:10:45 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727546AbfHMGKo (ORCPT ); Tue, 13 Aug 2019 02:10:44 -0400 Received: from mga03.intel.com ([134.134.136.65]:50516 "EHLO mga03.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726808AbfHMGKo (ORCPT ); Tue, 13 Aug 2019 02:10:44 -0400 X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from fmsmga007.fm.intel.com ([10.253.24.52]) by orsmga103.jf.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 12 Aug 2019 23:10:43 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.64,380,1559545200"; d="scan'208";a="177709469" Received: from rfried-mobl.ger.corp.intel.com (HELO [10.249.82.228]) ([10.249.82.228]) by fmsmga007.fm.intel.com with ESMTP; 12 Aug 2019 23:10:41 -0700 Subject: Re: [PATCH v2] gpiolib: Take MUX usage into account To: Stefan Wahren , 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> <1650c967-5176-70db-ff9a-b2af432ba1e7@i2se.com> From: "Fried, Ramon" Message-ID: <88cbb5b2-fd95-afb3-3645-e5b799844941@linux.intel.com> Date: Tue, 13 Aug 2019 09:10:37 +0300 User-Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:60.0) Gecko/20100101 Thunderbird/60.8.0 MIME-Version: 1.0 In-Reply-To: <1650c967-5176-70db-ff9a-b2af432ba1e7@i2se.com> Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 7bit Content-Language: en-US Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 8/13/2019 08:38, Stefan Wahren wrote: > 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. Basically, it's just the reversed return value you returned in the original patch, It means in this context that if the pin is not owned by a pin-controller it can be used for GPIO. Thanks, Ramon. > > Stefan >