[PATCH v2 1/8] drm/bridge: rgb-to-vga: Support an enable GPIO
From: Chen-Yu Tsai <hidden>
Date: 2016-10-20 03:43:55
Also in:
dri-devel, linux-devicetree, lkml
Subsystem:
drm drivers, drm drivers and misc gpu patches, drm drivers for bridge chips, open firmware and flattened device tree bindings, the rest · Maintainers:
David Airlie, Simona Vetter, Maarten Lankhorst, Maxime Ripard, Thomas Zimmermann, Andrzej Hajda, Neil Armstrong, Robert Foss, Rob Herring, Krzysztof Kozlowski, Conor Dooley, Linus Torvalds
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 <redacted> --- .../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 Example -------
diff --git a/drivers/gpu/drm/bridge/dumb-vga-dac.c b/drivers/gpu/drm/bridge/dumb-vga-dac.c
index afec232185a7..b487e5e9b56d 100644
--- a/drivers/gpu/drm/bridge/dumb-vga-dac.c
+++ b/drivers/gpu/drm/bridge/dumb-vga-dac.c@@ -10,6 +10,7 @@ * the License, or (at your option) any later version. */ +#include <linux/gpio/consumer.h> #include <linux/module.h> #include <linux/of_graph.h>
@@ -23,6 +24,7 @@ struct dumb_vga { struct drm_connector connector; struct i2c_adapter *ddc; + struct gpio_desc *enable_gpio; }; static inline struct dumb_vga *
@@ -124,8 +126,26 @@ static int dumb_vga_attach(struct drm_bridge *bridge) return 0; } +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); +} + +static void dumb_vga_disable(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, 0); +} + static const struct drm_bridge_funcs dumb_vga_bridge_funcs = { .attach = dumb_vga_attach, + .enable = dumb_vga_enable, + .disable = dumb_vga_disable, }; static struct i2c_adapter *dumb_vga_retrieve_ddc(struct device *dev)
@@ -169,6 +189,14 @@ static int dumb_vga_probe(struct platform_device *pdev) return -ENOMEM; platform_set_drvdata(pdev, vga); + vga->enable_gpio = devm_gpiod_get_optional(&pdev->dev, "enable", + GPIOD_OUT_LOW); + if (IS_ERR(vga->enable_gpio)) { + ret = PTR_ERR(vga->enable_gpio); + dev_err(&pdev->dev, "failed to request GPIO: %d\n", ret); + return ret; + } + vga->ddc = dumb_vga_retrieve_ddc(&pdev->dev); if (IS_ERR(vga->ddc)) { if (PTR_ERR(vga->ddc) == -ENODEV) {
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2.9.3