Hi Geert,


On 5/18/20 9:04 AM, Geert Uytterhoeven wrote:

Hi Mani,

On Mon, Apr 20, 2020 at 7:02 PM [off-list ref] wrote:

quoted

From: Manivannan Sadhasivam <mani@kernel.org>

Document the use of CTS/RTS gpios for flow control in STM32 UART
controller. These properties can be used instead of 'st,hw-flow-ctrl'
for making use of any gpio pins for flow control instead of dedicated
pins. It should be noted that both CTS/RTS and 'st,hw-flow-ctrl'
properties cannot co-exist in a design.

Reviewed-by: Andy Shevchenko <redacted>
Signed-off-by: Manivannan Sadhasivam <mani@kernel.org>

--- a/Documentation/devicetree/bindings/serial/st,stm32-uart.yaml
+++ b/Documentation/devicetree/bindings/serial/st,stm32-uart.yaml

@@ -55,6 +61,14 @@ properties:
    linux,rs485-enabled-at-boot-time: true
    rs485-rx-during-tx: true

+if:
+  required:
+    - st,hw-flow-ctrl

Perhaps "st,hw-flow-ctrl" should be deprecated, in favor of the standard
"uart-has-rtscts" property?
Of course the driver needs to gain support for the latter first.

You're fully right, the patch to deprecate "st, hw-flow-ctrl" and 
introduce generic "uart-has-rtscts" property in the driver is ready and 
will be sent this week on top of Mani patch.

quoted

+then:
+  properties:
+    cts-gpios: false
+    rts-gpios: false
+
  required:
    - compatible
    - reg

Gr{oetje,eeting}s,

                         Geert