user/sven/linux.git/include/uapi/linux/gpio.h, branch v5.9.10

gpio: uapi: fix misplaced comment line

2020-07-12T08:22:01Z

The second line of the description for event_type is before the first. Move it to after the first line. Signed-off-by: Kent Gibson Signed-off-by: Bartosz Golaszewski

gpio: uapi: Improve phrasing around arrays representing empty strings

2020-03-25T08:50:44Z

Character arrays can be considered empty strings (if they are immediately terminated), but they cannot be NULL. Signed-off-by: Jonathan Neuschäfer Signed-off-by: Bartosz Golaszewski

gpiolib: add new ioctl() for monitoring changes in line info

2020-02-12T11:05:47Z

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 Reviewed-by: Linus Walleij

gpio: add new SET_CONFIG ioctl() to gpio chardev

2019-11-12T15:30:31Z

Add the GPIOHANDLE_SET_CONFIG_IOCTL to the gpio chardev. The ioctl allows some of the configuration of a requested handle to be changed without having to release the line. The primary use case is the changing of direction for bi-directional lines. Based on initial work by Bartosz Golaszewski Signed-off-by: Kent Gibson Signed-off-by: Bartosz Golaszewski

gpiolib: add support for disabling line bias

2019-11-12T15:30:30Z

Allow pull up/down bias to be disabled, allowing the line to float or to be biased only by external circuitry. Use case is for where the bias has been applied previously, either by default or by the user, but that setting may conflict with the current use of the line. Signed-off-by: Kent Gibson Signed-off-by: Bartosz Golaszewski

gpio: expose pull-up/pull-down line flags to userspace

2019-11-12T15:30:30Z

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 [Kent: added BIAS to GPIO flag names and restrict application to input lines] Signed-off-by: Kent Gibson Signed-off-by: Bartosz Golaszewski

gpio: uapi: Grammar s/array/array of/

2018-09-13T08:46:24Z

Signed-off-by: Geert Uytterhoeven Signed-off-by: Linus Walleij

License cleanup: add SPDX license identifier to uapi header files with a license

2017-11-02T10:20:11Z

Many user space API headers have licensing information, which is either incomplete, badly formatted or just a shorthand for referring to the license under which the file is supposed to be. This makes it hard for compliance tools to determine the correct license. Update these files with an SPDX license identifier. The identifier was chosen based on the license information in the file. GPL/LGPL licensed headers get the matching GPL/LGPL SPDX license identifier with the added 'WITH Linux-syscall-note' exception, which is the officially assigned exception identifier for the kernel syscall exception: NOTE! This copyright does *not* cover user programs that use kernel services by normal system calls - this is merely considered normal use of the kernel, and does *not* fall under the heading of "derived work". This exception makes it possible to include GPL headers into non GPL code, without confusing license compliance tools. Headers which have either explicit dual licensing or are just licensed under a non GPL license are updated with the corresponding SPDX identifier and the GPLv2 with syscall exception identifier. The format is: ((GPL-2.0 WITH Linux-syscall-note) OR SPDX-ID-OF-OTHER-LICENSE) SPDX license identifiers are a legally binding shorthand, which can be used instead of the full boiler plate text. The update does not remove existing license information as this has to be done on a case by case basis and the copyright holders might have to be consulted. This will happen in a separate step. This patch is based on work done by Thomas Gleixner and Kate Stewart and Philippe Ombredanne. See the previous patch in this series for the methodology of how this patch was researched. Reviewed-by: Kate Stewart Reviewed-by: Philippe Ombredanne Reviewed-by: Thomas Gleixner Signed-off-by: Greg Kroah-Hartman

gpio: userspace ABI for reading GPIO line events

2016-06-15T07:29:17Z

This adds an ABI for listening to events on GPIO lines. The mechanism returns an anonymous file handle to a request to listen to a specific offset on a specific gpiochip. To fetch the stream of events from the file handle, userspace simply reads an event. - Events can be requested with the same flags as ordinary handles, i.e. open drain or open source. An ioctl() call GPIO_GET_LINEEVENT_IOCTL is issued indicating the desired line. - Events can be requested for falling edge events, rising edge events, or both. - All events are timestamped using the kernel real time nanosecond timestamp (the same as is used by IIO). - The supplied consumer label will appear in "lsgpio" listings of the lines, and in /proc/interrupts as the mechanism will request an interrupt from the gpio chip. - Events are not supported on gpiochips that do not serve interrupts (no legal .to_irq() call). The event interrupt is threaded to avoid any realtime problems. - It is possible to also directly read the current value of the registered GPIO line by issuing the same GPIOHANDLE_GET_LINE_VALUES_IOCTL as used by the line handles. Setting the value is not supported: we do not listen to events on output lines. This ABI is strongly influenced by Industrial I/O and surpasses the old sysfs ABI by providing proper precision timestamps, making it possible to set flags like open drain, and put consumer names on the GPIO lines. Signed-off-by: Linus Walleij

gpio: userspace ABI for reading/writing GPIO lines

2016-06-15T07:28:50Z

This adds a userspace ABI for reading and writing GPIO lines. The mechanism returns an anonymous file handle to a request to read/write n offsets from a gpiochip. This file handle in turn accepts two ioctl()s: one that reads and one that writes values to the selected lines. - Handles can be requested as input/output, active low, open drain, open source, however when you issue a request for n lines with GPIO_GET_LINEHANDLE_IOCTL, they must all have the same flags, i.e. all inputs or all outputs, all open drain etc. If a granular control of the flags for each line is desired, they need to be requested individually, not in a batch. - The GPIOHANDLE_GET_LINE_VALUES_IOCTL read ioctl() can be issued also to output lines to verify that the hardware is in the expected state. - It reads and writes up to GPIOHANDLES_MAX lines at once, utilizing the .set_multiple() call in the driver if possible, making the call efficient if several lines can be written with a single register update. The limitation of GPIOHANDLES_MAX to 64 lines is done under the assumption that we may expect hardware that can issue a transaction updating 64 bits at an instant but unlikely anything larger than that. ChangeLog v2->v3: - Use gpiod_get_value_cansleep() so we support also slowpath GPIO drivers. - Fix up the UAPI docs kerneldoc. - Allocate the anonymous fd last, so that the release function don't get called until that point of something fails. After this point, skip the errorpath. ChangeLog v1->v2: - Handle ioctl_compat() properly based on a similar patch to the other ioctl() handling code. - Use _IOWR() as we pass pointers both in and out of the ioctl() - Use kmalloc() and kfree() for the linehandled, do not try to be fancy with devm_* it doesn't work the way I thought. - Fix const-correctness on the linehandle name field. Acked-by: Michael Welling Signed-off-by: Linus Walleij