diff options
| author | Linus Walleij <linusw@kernel.org> | 2026-03-06 16:22:00 +0300 |
|---|---|---|
| committer | Bartosz Golaszewski <bartosz.golaszewski@oss.qualcomm.com> | 2026-03-09 12:16:00 +0300 |
| commit | 5645f805927c9bd4443e6143e487ef3ffea34aaf (patch) | |
| tree | 7a1b45ad07ddc589d2ea434e0d02c696f66b7716 /include/linux | |
| parent | 3671411e9073cb06d726dbf10835d158e18f0796 (diff) | |
| download | linux-5645f805927c9bd4443e6143e487ef3ffea34aaf.tar.xz | |
gpio: Document line value semantics
It is not clearly documented that the GPIO driver API expect the
driver to get/set the physical level of the GPIO line and the
consumer API will get/set the logic level. Document this in
relevant places.
Reported-by: David Jander <david@protonic.nl>
Signed-off-by: Linus Walleij <linusw@kernel.org>
Link: https://patch.msgid.link/20260306-gpio-doc-levels-v1-1-19928739e400@kernel.org
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@oss.qualcomm.com>
Diffstat (limited to 'include/linux')
| -rw-r--r-- | include/linux/gpio/driver.h | 10 |
1 files changed, 8 insertions, 2 deletions
diff --git a/include/linux/gpio/driver.h b/include/linux/gpio/driver.h index 5f5ddcbfa445..17511434ed07 100644 --- a/include/linux/gpio/driver.h +++ b/include/linux/gpio/driver.h @@ -343,11 +343,17 @@ struct gpio_irq_chip { * @direction_output: configures signal "offset" as output, returns 0 on * success or a negative error number. This can be omitted on input-only * or output-only gpio chips. - * @get: returns value for signal "offset", 0=low, 1=high, or negative error + * @get: returns value for signal "offset", 0=low, 1=high, or negative error. + * the low and high values are defined as physical low on the line + * in/out to the connector such as a physical pad, pin or rail. The GPIO + * library has internal logic to handle lines that are active low, such + * as indicated by overstrike or #name in a schematic, and the driver + * should not try to second-guess the logic value of a line. * @get_multiple: reads values for multiple signals defined by "mask" and * stores them in "bits", returns 0 on success or negative error * @set: assigns output value for signal "offset", returns 0 on success or - * negative error value + * negative error value. The output value follows the same semantic + * rules as for @get. * @set_multiple: assigns output values for multiple signals defined by * "mask", returns 0 on success or negative error value * @set_config: optional hook for all kinds of settings. Uses the same |