In order to support the "enable GPIO" available in many panel devices,
this commit adds a proper devicetree binding.
By providing an enable GPIO in the devicetree, the driver can now turn
off and on the panel device, and/or the backlight device. Both the
backlight and the GPIO are optional properties.
Tested-by: Darren Etheridge <detheridge@xxxxxx>
Signed-off-by: Ezequiel Garcia <ezequiel@xxxxxxxxxxxxxxxxxxxx>
---
.../devicetree/bindings/drm/tilcdc/panel.txt | 2 ++
drivers/gpu/drm/tilcdc/tilcdc_panel.c | 37 +++++++++++++++++++---
2 files changed, 34 insertions(+), 5 deletions(-)
diff --git a/Documentation/devicetree/bindings/drm/tilcdc/panel.txt b/Documentation/devicetree/bindings/drm/tilcdc/panel.txt
index 10a06e8..4ab9e23 100644
--- a/Documentation/devicetree/bindings/drm/tilcdc/panel.txt
+++ b/Documentation/devicetree/bindings/drm/tilcdc/panel.txt
@@ -20,6 +20,7 @@ Required properties:
Optional properties:
- backlight: phandle of the backlight device attached to the panel
+- enable-gpios: GPIO pin to enable or disable the panel
Recommended properties:
- pinctrl-names, pinctrl-0: the pincontrol settings to configure
@@ -33,6 +34,7 @@ Example:
pinctrl-names = "default";
pinctrl-0 = <&bone_lcd3_cape_lcd_pins>;
backlight = <&backlight>;
+ enable-gpios = <&gpio3 19 0>;
panel-info {
ac-bias = <255>;
diff --git a/drivers/gpu/drm/tilcdc/tilcdc_panel.c b/drivers/gpu/drm/tilcdc/tilcdc_panel.c
index f2a5b23..7a03158 100644
--- a/drivers/gpu/drm/tilcdc/tilcdc_panel.c
+++ b/drivers/gpu/drm/tilcdc/tilcdc_panel.c
@@ -18,6 +18,7 @@
#include <linux/pinctrl/pinmux.h>
#include <linux/pinctrl/consumer.h>
#include <linux/backlight.h>
+#include <linux/gpio/consumer.h>
#include <video/display_timing.h>
#include <video/of_display_timing.h>
#include <video/videomode.h>
@@ -29,6 +30,7 @@ struct panel_module {
struct tilcdc_panel_info *info;
struct display_timings *timings;
struct backlight_device *backlight;
+ struct gpio_desc *enable_gpio;
};
#define to_panel_module(x) container_of(x, struct panel_module, base)
@@ -55,13 +57,17 @@ static void panel_encoder_dpms(struct drm_encoder *encoder, int mode)
{
struct panel_encoder *panel_encoder = to_panel_encoder(encoder);
struct backlight_device *backlight = panel_encoder->mod->backlight;
+ struct gpio_desc *gpio = panel_encoder->mod->enable_gpio;
- if (!backlight)
- return;
+ if (backlight) {
+ backlight->props.power = mode == DRM_MODE_DPMS_ON ?
+ FB_BLANK_UNBLANK : FB_BLANK_POWERDOWN;
+ backlight_update_status(backlight);
+ }
- backlight->props.power = mode == DRM_MODE_DPMS_ON
- ? FB_BLANK_UNBLANK : FB_BLANK_POWERDOWN;
- backlight_update_status(backlight);
+ if (gpio)
+ gpiod_set_value_cansleep(gpio,
+ mode == DRM_MODE_DPMS_ON ? 1 : 0);
}
static bool panel_encoder_mode_fixup(struct drm_encoder *encoder,
@@ -369,6 +375,25 @@ static int panel_probe(struct platform_device *pdev)
dev_info(&pdev->dev, "found backlight\n");
}
+ panel_mod->enable_gpio = devm_gpiod_get(&pdev->dev, "enable");
+ if (IS_ERR(panel_mod->enable_gpio)) {
+ ret = PTR_ERR(panel_mod->enable_gpio);
+ if (ret != -ENOENT) {
+ dev_err(&pdev->dev, "failed to request enable GPIO\n");
+ goto fail_backlight;
+ }
+
+ /* Optional GPIO is not here, continue silently. */
+ panel_mod->enable_gpio = NULL;
+ } else {
+ ret = gpiod_direction_output(panel_mod->enable_gpio, 0);
+ if (ret < 0) {
+ dev_err(&pdev->dev, "failed to setup GPIO\n");
+ goto fail_backlight;
+ }
+ dev_info(&pdev->dev, "found enable GPIO\n");
+ }
+
mod = &panel_mod->base;
pdev->dev.platform_data = mod;
@@ -401,6 +426,8 @@ fail_timings:
fail_free:
tilcdc_module_cleanup(mod);
+
+fail_backlight:
if (panel_mod->backlight)
put_device(&panel_mod->backlight->dev);
return ret;
--
2.0.1
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