Re: [PATCH 3/3] tty/serial/8250: add DT bindings description for mctrl_gpio helpers

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



On Thu, Jul 27, 2017 at 03:17:36PM +0200, yegorslists@xxxxxxxxxxxxxx wrote:
> From: Yegor Yefremov <yegorslists@xxxxxxxxxxxxxx>
> 
> Describe {rts,cts,dtr,dsr,rng,dcd}-gpios usage.
> 
> Cc: Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx>
> Signed-off-by: Yegor Yefremov <yegorslists@xxxxxxxxxxxxxx>
> ---
>  Documentation/devicetree/bindings/serial/8250.txt | 26 +++++++++++++++++++++++
>  1 file changed, 26 insertions(+)
> 
> diff --git a/Documentation/devicetree/bindings/serial/8250.txt b/Documentation/devicetree/bindings/serial/8250.txt
> index 419ff6c..1c09db2 100644
> --- a/Documentation/devicetree/bindings/serial/8250.txt
> +++ b/Documentation/devicetree/bindings/serial/8250.txt
> @@ -48,6 +48,16 @@ Optional properties:
>  - tx-threshold: Specify the TX FIFO low water indication for parts with
>    programmable TX FIFO thresholds.
>  - resets : phandle + reset specifier pairs
> +- rts-gpios:
> +- cts-gpios:
> +- dtr-gpios:
> +- dsr-gpios:
> +- rng-gpios:
> +- dcd-gpios: specify a GPIO for RTS/CTS/DTR/DSR/RI/DCD
> +  line respectively. It will use specified GPIO instead of the peripheral
> +  function pin for the UART feature. If unsure, don't specify this property.

These are already described in serial.txt.

> +  If "wakeup-source" property is specified for the device this GPIO
> +  initialization will be aborted.

Why? Many GPIOs can function as wake-up sources. You would need get the 
IRQ for the GPIO. Also, some UARTs wake-up from the RX line. Not sure 
about any 8250 flavors, but is probably implementation specific what is 
the trigger for wake-up.

Rob
--
To unsubscribe from this list: send the line "unsubscribe linux-serial" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html



[Index of Archives]     [Kernel Newbies]     [Security]     [Netfilter]     [Bugtraq]     [Linux PPP]     [Linux FS]     [Yosemite News]     [MIPS Linux]     [ARM Linux]     [Linux Security]     [Linux RAID]     [Samba]     [Video 4 Linux]     [Linmodem]     [Device Mapper]     [Linux Kernel for ARM]

  Powered by Linux