From patchwork Sun Jan 13 21:21:34 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Stefan Wahren X-Patchwork-Id: 1024158 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Authentication-Results: ozlabs.org; spf=none (mailfrom) smtp.mailfrom=vger.kernel.org (client-ip=209.132.180.67; helo=vger.kernel.org; envelope-from=linux-gpio-owner@vger.kernel.org; receiver=) Authentication-Results: ozlabs.org; dmarc=none (p=none dis=none) header.from=i2se.com Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id 43d8gh28Zsz9s9h for ; Mon, 14 Jan 2019 08:22:07 +1100 (AEDT) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726591AbfAMVWF (ORCPT ); Sun, 13 Jan 2019 16:22:05 -0500 Received: from mout.kundenserver.de ([217.72.192.74]:43621 "EHLO mout.kundenserver.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726570AbfAMVWF (ORCPT ); Sun, 13 Jan 2019 16:22:05 -0500 Received: from localhost.localdomain ([37.4.249.153]) by mrelayeu.kundenserver.de (mreue107 [212.227.15.183]) with ESMTPSA (Nemesis) id 1N3bCH-1hPrEP1AaB-010ZXV; Sun, 13 Jan 2019 22:22:02 +0100 From: Stefan Wahren To: Linus Walleij , Bartosz Golaszewski Cc: linux-gpio@vger.kernel.org, Stefan Wahren Subject: [PATCH RFC] gpiolib: Take MUX usage into account Date: Sun, 13 Jan 2019 22:21:34 +0100 Message-Id: <1547414494-8556-1-git-send-email-stefan.wahren@i2se.com> X-Mailer: git-send-email 2.7.4 X-Provags-ID: V03:K1:NgdOhqzMbyFTtDzmW3RORykBlpblBHasrGOTMZKDesbPOHH+Azd fK4SZuJs2cFxJ1DPqk6qTzKWqVvEBfYRdMS/qTCpaJFZJ0RHjS4RXb0pZtVL5qyo1gll0ZM 7fEZFM9X5rxKVILBfJC/a8JE8keNEH7upm6VNFkSv3Keul4DHKlQLUsPa9yIcNi+mRa0f7v PhPl/8i3BmQ+fSB0FOaGA== X-Spam-Flag: NO X-UI-Out-Filterresults: notjunk:1; V03:K0:SueLfe68T90=:NUQQQa6y4pj3TU7zGilc26 lUz9RSeX/j+7/7SMcNWetDuKzT+9xWQOECa2Uw9Jcwrcfe+uG2uq6p/EF53XwcdDApYjupVOI ZDTnE6r7ohs03xyqubBl0y9s6sWWCAkPVrz6TDpkBqdIxDlC2M31PEt0rOUbHN2aYATyFSpa2 CrQ2FOF9Y4O3RKj2YN7reMA/Xjmu6wgQBXBfNgfATb5GRisobd/jT801iiA6B4lwevF/pM/0X O7A12ErupQoxyPGIHDF+XEDLge7H4twA/WpQwLZtbVLB7wapoiZB+RZ7bNXba6C2fpnDO1Quh nHE/kjNXy9vSH6pshpDRpVrh4obfTmlw8/w2oqPl/eZgzWYU9hDZrkgunuEoyq0yKEGf8Djq0 +RePmQW4xnrtARAMOFRvN8lr+6mhVCt9XyvArffYJh/B1JVXMChmcioWE5zQSt9t+zWkqQ2+h eFohSlVWMkhRGpGJQ6hSK7ImdG1IykFyXXIQOtFLY59/ZFb98YnjFcpyioU+zTaYSllTij4/2 bRhy0Wj6DSPRs8jx05XjMA0swh9kysflmyqxRlvNQI1gyUfj0MrrhyJNbVp6bzalx8dbPp+6a avXKoaps90WfLhu/QeJ561ISomOyNKo11wyid2tBGx42X2FFSH8nwBjkgpSm9Hh45jCHohBxJ Z8DKTbCSvP86No7Nuq/EeTcz1Ck6+JjLGVz7bgedQDUBPTwMty3r+y9TCAEB4qvmZioQf2zSQ CgJ/gnbkz9QOohtYa4TC9eRYKfkjZ/ToKI6gQ6FwjgA5jEtUiv3MzXQB3Kk= Sender: linux-gpio-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-gpio@vger.kernel.org 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 into account to get a more realistic view for ioctl GPIO_GET_LINEINFO_IOCTL. Signed-off-by: Stefan Wahren --- drivers/gpio/gpiolib.c | 3 ++- drivers/pinctrl/core.c | 23 +++++++++++++++++++++++ drivers/pinctrl/pinmux.c | 17 +++++++++++++++++ drivers/pinctrl/pinmux.h | 7 +++++++ include/linux/pinctrl/consumer.h | 6 ++++++ 5 files changed, 55 insertions(+), 1 deletion(-) Hi, as proposed in a recent discussion [1], this is a hack to improve gpioinfo. I think this could a start point for a discussion. Obvious drawback is the resulting overhead for the ioctl call. Stefan [1] - https://marc.info/?l=linux-gpio&m=154644476313636 diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c index 1651d7f..da3b008 100644 --- a/drivers/gpio/gpiolib.c +++ b/drivers/gpio/gpiolib.c @@ -1075,7 +1075,8 @@ 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_is_in_use(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 c6ff4d5..6e097e4 100644 --- a/drivers/pinctrl/core.c +++ b/drivers/pinctrl/core.c @@ -760,6 +760,29 @@ int pinctrl_get_group_selector(struct pinctrl_dev *pctldev, return -EINVAL; } +bool pinctrl_gpio_is_in_use(unsigned gpio) +{ + struct pinctrl_dev *pctldev; + struct pinctrl_gpio_range *range; + bool result; + int pin; + + if (pinctrl_get_device_gpio_range(gpio, &pctldev, &range)) + return false; + + mutex_lock(&pctldev->mutex); + + /* Convert to the pin controllers number space */ + pin = gpio_to_pin(range, gpio); + + result = pinmux_is_in_use(pctldev, pin); + + mutex_unlock(&pctldev->mutex); + + return result; +} +EXPORT_SYMBOL_GPL(pinctrl_gpio_is_in_use); + /** * 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 4d0cc18..0a5bab2 100644 --- a/drivers/pinctrl/pinmux.c +++ b/drivers/pinctrl/pinmux.c @@ -71,6 +71,23 @@ int pinmux_validate_map(const struct pinctrl_map *map, int i) return 0; } +bool pinmux_is_in_use(struct pinctrl_dev *pctldev, unsigned pin) +{ + struct pin_desc *desc = pin_desc_get(pctldev, pin); + + if (!desc) { + dev_err(pctldev->dev, + "pin %u is not registered so it cannot be requested\n", + pin); + return false; + } + + if (desc->mux_usecount) + return true; + + return !!desc->gpio_owner; +} + /** * pin_request() - request a single pin to be muxed in, typically for GPIO * @pin: the pin number in the global pin space diff --git a/drivers/pinctrl/pinmux.h b/drivers/pinctrl/pinmux.h index 3319535..1da2a75 100644 --- a/drivers/pinctrl/pinmux.h +++ b/drivers/pinctrl/pinmux.h @@ -16,6 +16,8 @@ int pinmux_check_ops(struct pinctrl_dev *pctldev); int pinmux_validate_map(const struct pinctrl_map *map, int i); +bool pinmux_is_in_use(struct pinctrl_dev *pctldev, unsigned pin); + int pinmux_request_gpio(struct pinctrl_dev *pctldev, struct pinctrl_gpio_range *range, unsigned pin, unsigned gpio); @@ -43,6 +45,11 @@ static inline int pinmux_validate_map(const struct pinctrl_map *map, int i) return 0; } +static inline bool pinmux_is_in_use(struct pinctrl_dev *pctldev, unsigned pin) +{ + return false; +} + static inline int pinmux_request_gpio(struct pinctrl_dev *pctldev, struct pinctrl_gpio_range *range, unsigned pin, unsigned gpio) diff --git a/include/linux/pinctrl/consumer.h b/include/linux/pinctrl/consumer.h index 0412cc9..0093a2b 100644 --- a/include/linux/pinctrl/consumer.h +++ b/include/linux/pinctrl/consumer.h @@ -25,6 +25,7 @@ struct device; #ifdef CONFIG_PINCTRL /* External interface to pin control */ +extern bool pinctrl_gpio_is_in_use(unsigned gpio); extern int pinctrl_gpio_request(unsigned gpio); extern void pinctrl_gpio_free(unsigned gpio); extern int pinctrl_gpio_direction_input(unsigned gpio); @@ -62,6 +63,11 @@ static inline int pinctrl_pm_select_idle_state(struct device *dev) #else /* !CONFIG_PINCTRL */ +static inline bool pinctrl_gpio_is_in_use(unsigned gpio) +{ + return 0; +} + static inline int pinctrl_gpio_request(unsigned gpio) { return 0;