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authorGravatar Richard Genoud <richard.genoud@gmail.com> 2014-05-13 20:20:44 +0200
committerGravatar Greg Kroah-Hartman <gregkh@linuxfoundation.org> 2014-05-28 12:49:44 -0700
commite0b0baadb7a4509bdcd5ba37d0be61e2c4bb0d48 (patch)
treeea9d6937dddf11ed65c8b9c2f8847213f73e2d2e /Documentation
parenttty/serial: Add GPIOLIB helpers for controlling modem lines (diff)
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tty/serial: at91: use mctrl_gpio helpers
On sam9x5, dedicated CTS (and RTS) pins are unusable together with the LCDC, the EMAC, or the MMC because they share the same line. Moreover, the USART 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: Richard Genoud <richard.genoud@gmail.com> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Acked-by: Nicolas Ferre <nicolas.ferre@atmel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'Documentation')
-rw-r--r--Documentation/devicetree/bindings/serial/atmel-usart.txt10
1 files changed, 8 insertions, 2 deletions
diff --git a/Documentation/devicetree/bindings/serial/atmel-usart.txt b/Documentation/devicetree/bindings/serial/atmel-usart.txt
index 2f7aad71b3c9..a6391e70a8fd 100644
--- a/Documentation/devicetree/bindings/serial/atmel-usart.txt
+++ b/Documentation/devicetree/bindings/serial/atmel-usart.txt
@@ -13,8 +13,9 @@ Required properties:
Optional properties:
- atmel,use-dma-rx: use of PDC or DMA for receiving data
- atmel,use-dma-tx: use of PDC or DMA for transmitting data
-- rts-gpios: specify a GPIO for RTS line. It will use specified PIO instead of the peripheral
- function pin for the USART RTS feature. If unsure, don't specify this property.
+- {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.
- add dma bindings for dma transfer:
- dmas: DMA specifier, consisting of a phandle to DMA controller node,
memory peripheral interface and USART DMA channel ID, FIFO configuration.
@@ -36,6 +37,11 @@ Example:
atmel,use-dma-rx;
atmel,use-dma-tx;
rts-gpios = <&pioD 15 GPIO_ACTIVE_LOW>;
+ cts-gpios = <&pioD 16 GPIO_ACTIVE_LOW>;
+ dtr-gpios = <&pioD 17 GPIO_ACTIVE_LOW>;
+ dsr-gpios = <&pioD 18 GPIO_ACTIVE_LOW>;
+ dcd-gpios = <&pioD 20 GPIO_ACTIVE_LOW>;
+ rng-gpios = <&pioD 19 GPIO_ACTIVE_LOW>;
};
- use DMA: