From mboxrd@z Thu Jan 1 00:00:00 1970 From: maxime.ripard@free-electrons.com (Maxime Ripard) Date: Thu, 27 Oct 2016 00:17:24 +0200 Subject: [PATCH v2 1/8] drm/bridge: rgb-to-vga: Support an enable GPIO In-Reply-To: <20161026221346.tdpmbrwca4jehch2@rob-hp-laptop> References: <20161020034344.14154-1-wens@csie.org> <20161020034344.14154-2-wens@csie.org> <20161026221346.tdpmbrwca4jehch2@rob-hp-laptop> Message-ID: <20161026221724.55yufeql6s5nd5gq@lukather> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org Hi Rob, On Wed, Oct 26, 2016 at 05:13:46PM -0500, Rob Herring wrote: > On Thu, Oct 20, 2016 at 11:43:37AM +0800, Chen-Yu Tsai wrote: > > Some rgb-to-vga bridges have an enable GPIO, either directly tied to > > an enable pin on the bridge IC, or indirectly controlling a power > > switch. > > > > Add support for it. > > > > Signed-off-by: Chen-Yu Tsai > > --- > > .../bindings/display/bridge/dumb-vga-dac.txt | 2 ++ > > drivers/gpu/drm/bridge/dumb-vga-dac.c | 28 ++++++++++++++++++++++ > > 2 files changed, 30 insertions(+) > > > > diff --git a/Documentation/devicetree/bindings/display/bridge/dumb-vga-dac.txt b/Documentation/devicetree/bindings/display/bridge/dumb-vga-dac.txt > > index 003bc246a270..d3484822bf77 100644 > > --- a/Documentation/devicetree/bindings/display/bridge/dumb-vga-dac.txt > > +++ b/Documentation/devicetree/bindings/display/bridge/dumb-vga-dac.txt > > @@ -16,6 +16,8 @@ graph bindings specified in Documentation/devicetree/bindings/graph.txt. > > - Video port 0 for RGB input > > - Video port 1 for VGA output > > > > +Optional properties: > > +- enable-gpios: GPIO pin to enable or disable the bridge > > This should also define the active state. > > > +static void dumb_vga_enable(struct drm_bridge *bridge) > > +{ > > + struct dumb_vga *vga = drm_bridge_to_dumb_vga(bridge); > > + > > + if (vga->enable_gpio) > > + gpiod_set_value_cansleep(vga->enable_gpio, 1); > > So the driver should allow either active high or low. You mean like having a enable-active-high property? Isn't that redundant with the GPIO flags? Maxime -- Maxime Ripard, Free Electrons Embedded Linux and Kernel engineering http://free-electrons.com -------------- next part -------------- A non-text attachment was scrubbed... Name: signature.asc Type: application/pgp-signature Size: 801 bytes Desc: not available URL: