diff options
author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-06-19 21:00:51 +0000 |
---|---|---|
committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-06-19 21:00:51 +0000 |
commit | 6d03a247468059b0e59c821ef39e6762d4d6fc30 (patch) | |
tree | 17b9c00de2c62e68c965c742cdbc206f77a375da /Documentation/driver-api/gpio/consumer.rst | |
parent | Releasing progress-linux version 6.8.12-1~progress7.99u1. (diff) | |
download | linux-6d03a247468059b0e59c821ef39e6762d4d6fc30.tar.xz linux-6d03a247468059b0e59c821ef39e6762d4d6fc30.zip |
Merging upstream version 6.9.2.
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'Documentation/driver-api/gpio/consumer.rst')
-rw-r--r-- | Documentation/driver-api/gpio/consumer.rst | 10 |
1 files changed, 5 insertions, 5 deletions
diff --git a/Documentation/driver-api/gpio/consumer.rst b/Documentation/driver-api/gpio/consumer.rst index 3e588b9d6..ab56ab0dd 100644 --- a/Documentation/driver-api/gpio/consumer.rst +++ b/Documentation/driver-api/gpio/consumer.rst @@ -222,9 +222,9 @@ Use the following calls to access GPIOs from an atomic context:: int gpiod_get_value(const struct gpio_desc *desc); void gpiod_set_value(struct gpio_desc *desc, int value); -The values are boolean, zero for low, nonzero for high. When reading the value -of an output pin, the value returned should be what's seen on the pin. That -won't always match the specified output value, because of issues including +The values are boolean, zero for inactive, nonzero for active. When reading the +value of an output pin, the value returned should be what's seen on the pin. +That won't always match the specified output value, because of issues including open-drain signaling and output latencies. The get/set calls do not return errors because "invalid GPIO" should have been @@ -277,11 +277,11 @@ switch their output to a high impedance value. The consumer should not need to care. (For details read about open drain in driver.rst.) With this, all the gpiod_set_(array)_value_xxx() functions interpret the -parameter "value" as "asserted" ("1") or "de-asserted" ("0"). The physical line +parameter "value" as "active" ("1") or "inactive" ("0"). The physical line level will be driven accordingly. As an example, if the active low property for a dedicated GPIO is set, and the -gpiod_set_(array)_value_xxx() passes "asserted" ("1"), the physical line level +gpiod_set_(array)_value_xxx() passes "active" ("1"), the physical line level will be driven low. To summarize:: |