From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To: Bartosz Golaszewski <brgl@bgdev.pl>
Cc: Kent Gibson <warthog618@gmail.com>,
Linus Walleij <linus.walleij@linaro.org>,
Andy Shevchenko <andriy.shevchenko@linux.intel.com>,
linux-gpio@vger.kernel.org, linux-kernel@vger.kernel.org,
Bartosz Golaszewski <bgolaszewski@baylibre.com>
Subject: Re: [PATCH v3 12/13] gpiolib: add new ioctl() for monitoring changes in line info
Date: Thu, 19 Dec 2019 18:24:14 +0100 [thread overview]
Message-ID: <20191219172414.GA2094615@kroah.com> (raw)
In-Reply-To: <20191219171528.6348-13-brgl@bgdev.pl>
On Thu, Dec 19, 2019 at 06:15:27PM +0100, Bartosz Golaszewski wrote:
> From: Bartosz Golaszewski <bgolaszewski@baylibre.com>
>
> Currently there is no way for user-space to be informed about changes
> in status of GPIO lines e.g. when someone else requests the line or its
> config changes. We can only periodically re-read the line-info. This
> is fine for simple one-off user-space tools, but any daemon that provides
> a centralized access to GPIO chips would benefit hugely from an event
> driven line info synchronization.
>
> This patch adds a new ioctl() that allows user-space processes to reuse
> the file descriptor associated with the character device for watching
> any changes in line properties. Every such event contains the updated
> line information.
>
> Currently the events are generated on three types of status changes: when
> a line is requested, when it's released and when its config is changed.
> The first two are self-explanatory. For the third one: this will only
> happen when another user-space process calls the new SET_CONFIG ioctl()
> as any changes that can happen from within the kernel (i.e.
> set_transitory() or set_debounce()) are of no interest to user-space.
>
> Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
> ---
> drivers/gpio/gpiolib.c | 191 ++++++++++++++++++++++++++++++++++++--
> drivers/gpio/gpiolib.h | 1 +
> include/uapi/linux/gpio.h | 24 +++++
> tools/gpio/gpio-watch | Bin 0 -> 26528 bytes
Did you mean for this binary file to be checked in?
next prev parent reply other threads:[~2019-12-19 17:24 UTC|newest]
Thread overview: 22+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-12-19 17:15 [PATCH v3 00/13] gpiolib: add an ioctl() for monitoring line status changes Bartosz Golaszewski
2019-12-19 17:15 ` [PATCH v3 01/13] gpiolib: use 'unsigned int' instead of 'unsigned' in gpio_set_config() Bartosz Golaszewski
2019-12-19 17:15 ` [PATCH v3 02/13] gpiolib: have a single place of calling set_config() Bartosz Golaszewski
2019-12-19 17:15 ` [PATCH v3 03/13] gpiolib: convert the type of hwnum to unsigned int in gpiochip_get_desc() Bartosz Golaszewski
2019-12-19 17:15 ` [PATCH v3 04/13] gpiolib: use gpiochip_get_desc() in linehandle_create() Bartosz Golaszewski
2019-12-19 17:15 ` [PATCH v3 05/13] gpiolib: use gpiochip_get_desc() in lineevent_create() Bartosz Golaszewski
2019-12-19 17:15 ` [PATCH v3 06/13] gpiolib: use gpiochip_get_desc() in gpio_ioctl() Bartosz Golaszewski
2019-12-19 17:15 ` [PATCH v3 07/13] kfifo: provide noirqsave variants of spinlocked in and out helpers Bartosz Golaszewski
2019-12-19 17:15 ` [PATCH v3 08/13] kfifo: provide kfifo_is_empty_spinlocked() Bartosz Golaszewski
2019-12-19 17:15 ` [PATCH v3 09/13] gpiolib: rework the locking mechanism for lineevent kfifo Bartosz Golaszewski
2019-12-19 17:15 ` [PATCH v3 10/13] gpiolib: emit a debug message when adding events to a full kfifo Bartosz Golaszewski
2019-12-19 17:15 ` [PATCH v3 11/13] gpiolib: provide a dedicated function for setting lineinfo Bartosz Golaszewski
2019-12-19 17:15 ` [PATCH v3 12/13] gpiolib: add new ioctl() for monitoring changes in line info Bartosz Golaszewski
2019-12-19 17:24 ` Greg Kroah-Hartman [this message]
2019-12-20 8:45 ` Bartosz Golaszewski
2019-12-19 18:17 ` Andy Shevchenko
2019-12-20 11:25 ` Bartosz Golaszewski
2019-12-20 12:15 ` Andy Shevchenko
2019-12-20 17:29 ` Bartosz Golaszewski
2019-12-24 12:09 ` Bartosz Golaszewski
2019-12-24 12:08 ` Bartosz Golaszewski
2019-12-19 17:15 ` [PATCH v3 13/13] tools: gpio: implement gpio-watch Bartosz Golaszewski
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