Re: [PATCH v2 2/5] fbdev: ssd1307fb: Remove reset-active-low from the DT binding document

On 01/19/17 00:28, Rob Herring wrote:

On Fri, Jan 13, 2017 at 12:35:46PM +0200, Jyri Sarha wrote:

quoted

Remove reset-active-low from the devicetree binding document. The actual
implementation has never been there in the driver code and there is no
reason to add it because the gpiod API supports gpio flags, including
GPIO_ACTIVE_LOW, directly trough its own devicetree binding.

Signed-off-by: Jyri Sarha <redacted>
---
 Documentation/devicetree/bindings/display/ssd1307fb.txt | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/Documentation/devicetree/bindings/display/ssd1307fb.txt b/Documentation/devicetree/bindings/display/ssd1307fb.txt
index eb31ed4..4aee67f 100644
--- a/Documentation/devicetree/bindings/display/ssd1307fb.txt
+++ b/Documentation/devicetree/bindings/display/ssd1307fb.txt

@@ -8,14 +8,14 @@ Required properties:
          0x3c or 0x3d
   - pwm: Should contain the pwm to use according to the OF device tree PWM
          specification [0]. Only required for the ssd1307.
-  - reset-gpios: Should contain the GPIO used to reset the OLED display
+  - reset-gpios: Should contain the GPIO used to reset the OLED display. See
+                 Documentation/devicetree/bindings/gpio/gpio.txt for details.

You need to define the active state. Does the active state actually 
vary? Sounds like the compatible is not specific enough unless some 
boards have an inverter.

No, I am not aware of the active state ever varying. For some reason
someone specified the reset-active-low, but probably in the end it was
not needed after all because the implementation was not added.

The only reason I can think of why the reset gpio would need active low
flag is very weird board design or broken gpio driver.

Best regards,
Jyri