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[220.235.84.126]) by smtp.gmail.com with ESMTPSA id b20sm12042242pff.158.2019.10.11.18.56.54 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 11 Oct 2019 18:56:56 -0700 (PDT) From: Kent Gibson To: linux-gpio@vger.kernel.org, brgl@bgdev.pl, linus.walleij@linaro.org, bamv2005@gmail.com Cc: drew@pdp7.com, Bartosz Golaszewski Subject: [PATCH v2 1/6] gpio: expose pull-up/pull-down line flags to userspace Date: Sat, 12 Oct 2019 09:56:23 +0800 Message-Id: <20191012015628.9604-2-warthog618@gmail.com> X-Mailer: git-send-email 2.23.0 In-Reply-To: <20191012015628.9604-1-warthog618@gmail.com> References: <20191012015628.9604-1-warthog618@gmail.com> MIME-Version: 1.0 Sender: linux-gpio-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-gpio@vger.kernel.org From: Drew Fustini Add pull-up/pull-down flags to the gpio line get and set ioctl() calls. Use cases include a push button that does not have an external resistor. Addition use cases described by Limor Fried (ladyada) of Adafruit in this PR for Adafruit_Blinka Python lib: https://github.com/adafruit/Adafruit_Blinka/pull/59 Signed-off-by: Drew Fustini [Bartosz: added flag sanitization] Signed-off-by: Bartosz Golaszewski --- drivers/gpio/gpiolib.c | 17 +++++++++++++++++ include/uapi/linux/gpio.h | 4 ++++ 2 files changed, 21 insertions(+) diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c index bdbc1649eafa..9d2a5e2f6e77 100644 --- a/drivers/gpio/gpiolib.c +++ b/drivers/gpio/gpiolib.c @@ -421,6 +421,8 @@ struct linehandle_state { (GPIOHANDLE_REQUEST_INPUT | \ GPIOHANDLE_REQUEST_OUTPUT | \ GPIOHANDLE_REQUEST_ACTIVE_LOW | \ + GPIOHANDLE_REQUEST_PULL_UP | \ + GPIOHANDLE_REQUEST_PULL_DOWN | \ GPIOHANDLE_REQUEST_OPEN_DRAIN | \ GPIOHANDLE_REQUEST_OPEN_SOURCE) @@ -537,6 +539,11 @@ static int linehandle_create(struct gpio_device *gdev, void __user *ip) (lflags & GPIOHANDLE_REQUEST_OUTPUT)) return -EINVAL; + /* Same with pull-up and pull-down. */ + if ((lflags & GPIOHANDLE_REQUEST_PULL_UP) && + (lflags & GPIOHANDLE_REQUEST_PULL_DOWN)) + return -EINVAL; + /* * Do not allow OPEN_SOURCE & OPEN_DRAIN flags in a single request. If * the hardware actually supports enabling both at the same time the @@ -592,6 +599,10 @@ static int linehandle_create(struct gpio_device *gdev, void __user *ip) set_bit(FLAG_OPEN_DRAIN, &desc->flags); if (lflags & GPIOHANDLE_REQUEST_OPEN_SOURCE) set_bit(FLAG_OPEN_SOURCE, &desc->flags); + if (lflags & GPIOHANDLE_REQUEST_PULL_DOWN) + set_bit(FLAG_PULL_DOWN, &desc->flags); + if (lflags & GPIOHANDLE_REQUEST_PULL_UP) + set_bit(FLAG_PULL_UP, &desc->flags); ret = gpiod_set_transitory(desc, false); if (ret < 0) @@ -1097,6 +1108,10 @@ static long gpio_ioctl(struct file *filp, unsigned int cmd, unsigned long arg) if (test_bit(FLAG_OPEN_SOURCE, &desc->flags)) lineinfo.flags |= (GPIOLINE_FLAG_OPEN_SOURCE | GPIOLINE_FLAG_IS_OUT); + if (test_bit(FLAG_PULL_DOWN, &desc->flags)) + lineinfo.flags |= GPIOLINE_FLAG_PULL_DOWN; + if (test_bit(FLAG_PULL_UP, &desc->flags)) + lineinfo.flags |= GPIOLINE_FLAG_PULL_UP; if (copy_to_user(ip, &lineinfo, sizeof(lineinfo))) return -EFAULT; @@ -2770,6 +2785,8 @@ static bool gpiod_free_commit(struct gpio_desc *desc) clear_bit(FLAG_REQUESTED, &desc->flags); clear_bit(FLAG_OPEN_DRAIN, &desc->flags); clear_bit(FLAG_OPEN_SOURCE, &desc->flags); + clear_bit(FLAG_PULL_UP, &desc->flags); + clear_bit(FLAG_PULL_DOWN, &desc->flags); clear_bit(FLAG_IS_HOGGED, &desc->flags); ret = true; } diff --git a/include/uapi/linux/gpio.h b/include/uapi/linux/gpio.h index 4ebfe0ac6c5b..c2d1f7d908d6 100644 --- a/include/uapi/linux/gpio.h +++ b/include/uapi/linux/gpio.h @@ -33,6 +33,8 @@ struct gpiochip_info { #define GPIOLINE_FLAG_ACTIVE_LOW (1UL << 2) #define GPIOLINE_FLAG_OPEN_DRAIN (1UL << 3) #define GPIOLINE_FLAG_OPEN_SOURCE (1UL << 4) +#define GPIOLINE_FLAG_PULL_UP (1UL << 5) +#define GPIOLINE_FLAG_PULL_DOWN (1UL << 6) /** * struct gpioline_info - Information about a certain GPIO line @@ -62,6 +64,8 @@ struct gpioline_info { #define GPIOHANDLE_REQUEST_ACTIVE_LOW (1UL << 2) #define GPIOHANDLE_REQUEST_OPEN_DRAIN (1UL << 3) #define GPIOHANDLE_REQUEST_OPEN_SOURCE (1UL << 4) +#define GPIOHANDLE_REQUEST_PULL_UP (1UL << 5) +#define GPIOHANDLE_REQUEST_PULL_DOWN (1UL << 6) /** * struct gpiohandle_request - Information about a GPIO handle request