From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jyri Sarha Date: Thu, 19 Jan 2017 08:24:00 +0000 Subject: Re: [PATCH v2 2/5] fbdev: ssd1307fb: Remove reset-active-low from the DT binding document Message-Id: List-Id: References: <20170118222804.ifqkkffot5n55gsk@rob-hp-laptop> In-Reply-To: <20170118222804.ifqkkffot5n55gsk@rob-hp-laptop> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: Rob Herring Cc: linux-fbdev-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, devicetree-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, b.zolnierkie-Sze3O3UU22JBDgjK7y7TUQ@public.gmane.org, tomi.valkeinen-l0cyMroinI0@public.gmane.org, maxime.ripard-wi1+55ScJUtKEb57/3fJTNBPR1lH4CV8@public.gmane.org, bcousson-rdvid1DuHRBWk0Htik3J/w@public.gmane.org On 01/19/17 00:28, Rob Herring wrote: > On Fri, Jan 13, 2017 at 12:35:46PM +0200, Jyri Sarha wrote: >> 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 >> --- >> 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