diff options
| author |   Janusz Uzycki <j.uzycki@elproma.com.pl> | 2014-10-10 18:53:25 +0200 |
|---|---|---|
| committer |   Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2014-11-06 14:57:18 -0800 |
| commit | 7c573d7ea6c5a866cf89b7bf45fc5ab82d289cf1 (patch) | |
| tree | a8bf7ee47df629ff81802f1582538c3f047b534f /Documentation/devicetree/bindings/serial | |
| parent | serial: mxs-auart: clean get_mctrl and set_mctrl (diff) | |
| download | linux-dev-7c573d7ea6c5a866cf89b7bf45fc5ab82d289cf1.tar.xz linux-dev-7c573d7ea6c5a866cf89b7bf45fc5ab82d289cf1.zip | |
serial: mxs-auart: use mctrl_gpio helpers for handling modem signals
Dedicated CTS and RTS pins are unusable together with a lot of other
peripherals because they share the same line. Pinctrl is limited.
Moreover, the AUART controller doesn't handle DTR/DSR/DCD/RI signals,
so we have to control them via GPIO.
This patch permits to use GPIOs to control the CTS/RTS/DTR/DSR/DCD/RI
signals.
Signed-off-by: Janusz Uzycki <j.uzycki@elproma.com.pl>
Reviewed-by: Richard Genoud <richard.genoud@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'Documentation/devicetree/bindings/serial')
| -rw-r--r-- | Documentation/devicetree/bindings/serial/fsl-mxs-auart.txt | 10 |
1 files changed, 9 insertions, 1 deletions
diff --git a/Documentation/devicetree/bindings/serial/fsl-mxs-auart.txt b/Documentation/devicetree/bindings/serial/fsl-mxs-auart.txt index 59a40f18d551..7c408c87e613 100644 --- a/Documentation/devicetree/bindings/serial/fsl-mxs-auart.txt +++ b/Documentation/devicetree/bindings/serial/fsl-mxs-auart.txt @@ -11,8 +11,13 @@ Required properties: - dma-names: "rx" for RX channel, "tx" for TX channel. Optional properties: -- fsl,uart-has-rtscts : Indicate the UART has RTS and CTS lines, +- fsl,uart-has-rtscts : Indicate the UART has RTS and CTS lines + for hardware flow control, it also means you enable the DMA support for this UART. +- {rts,cts,dtr,dsr,rng,dcd}-gpios: specify a GPIO for RTS/CTS/DTR/DSR/RI/DCD + line respectively. It will use specified PIO instead of the peripheral + function pin for the USART feature. + If unsure, don't specify this property. Example: auart0: serial@8006a000 { @@ -21,6 +26,9 @@ auart0: serial@8006a000 { interrupts = <112>; dmas = <&dma_apbx 8>, <&dma_apbx 9>; dma-names = "rx", "tx"; + cts-gpios = <&gpio1 15 GPIO_ACTIVE_LOW>; + dsr-gpios = <&gpio1 16 GPIO_ACTIVE_LOW>; + dcd-gpios = <&gpio1 17 GPIO_ACTIVE_LOW>; }; Note: Each auart port should have an alias correctly numbered in "aliases" |