diff options
| author | Richard Genoud <richard.genoud@gmail.com> | 2014-05-13 20:20:43 +0200 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2014-05-28 21:49:14 +0200 |
| commit | 84130aace83989c1dba073ed98dad721d2060258 (patch) | |
| tree | e313e54a9276328a551825f58fc867aa02f8acf1 /Documentation | |
| parent | ARM: at91: gpio: implement get_direction (diff) | |
| download | linux-84130aace83989c1dba073ed98dad721d2060258.tar.xz linux-84130aace83989c1dba073ed98dad721d2060258.zip | |
tty/serial: Add GPIOLIB helpers for controlling modem lines
This patch add some helpers to control modem lines (CTS/RTS/DSR...) via
GPIO.
This will be useful for many boards which have a serial controller that
only handle CTS/RTS pins (or even just RX/TX).
Signed-off-by: Richard Genoud <richard.genoud@gmail.com>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Tested-by: Yegor Yefremov <yegorslists@googlemail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'Documentation')
| -rw-r--r-- | Documentation/serial/driver | 25 |
1 files changed, 25 insertions, 0 deletions
diff --git a/Documentation/serial/driver b/Documentation/serial/driver index c3a7689a90e6..3bba1aeb799c 100644 --- a/Documentation/serial/driver +++ b/Documentation/serial/driver @@ -429,3 +429,28 @@ thus: struct uart_port port; int my_stuff; }; + +Modem control lines via GPIO +---------------------------- + +Some helpers are provided in order to set/get modem control lines via GPIO. + +mctrl_gpio_init(dev, idx): + This will get the {cts,rts,...}-gpios from device tree if they are + present and request them, set direction etc, and return an + allocated structure. devm_* functions are used, so there's no need + to call mctrl_gpio_free(). + +mctrl_gpio_free(dev, gpios): + This will free the requested gpios in mctrl_gpio_init(). + As devm_* function are used, there's generally no need to call + this function. + +mctrl_gpio_to_gpiod(gpios, gidx) + This returns the gpio structure associated to the modem line index. + +mctrl_gpio_set(gpios, mctrl): + This will sets the gpios according to the mctrl state. + +mctrl_gpio_get(gpios, mctrl): + This will update mctrl with the gpios values. |