The current backlight support is broken; the driver expects a backlight-class
in the panel devicetree node. Fix this by implementing it properly, getting
an optional backlight from a phandle.
This shouldn't cause any backward-compatibility DT issue because the current
implementation doesn't work and is not even documented.
Signed-off-by: Ezequiel Garcia <ezequiel@xxxxxxxxxxxxxxxxxxxx>
---
.../devicetree/bindings/drm/tilcdc/panel.txt | 5 +++++
drivers/gpu/drm/tilcdc/tilcdc_panel.c | 23 +++++++++++++++++-----
2 files changed, 23 insertions(+), 5 deletions(-)
diff --git a/Documentation/devicetree/bindings/drm/tilcdc/panel.txt b/Documentation/devicetree/bindings/drm/tilcdc/panel.txt
index 9301c33..10a06e8 100644
--- a/Documentation/devicetree/bindings/drm/tilcdc/panel.txt
+++ b/Documentation/devicetree/bindings/drm/tilcdc/panel.txt
@@ -18,6 +18,9 @@ Required properties:
Documentation/devicetree/bindings/video/display-timing.txt for display
timing binding details.
+Optional properties:
+- backlight: phandle of the backlight device attached to the panel
+
Recommended properties:
- pinctrl-names, pinctrl-0: the pincontrol settings to configure
muxing properly for pins that connect to TFP410 device
@@ -29,6 +32,8 @@ Example:
compatible = "ti,tilcdc,panel";
pinctrl-names = "default";
pinctrl-0 = <&bone_lcd3_cape_lcd_pins>;
+ backlight = <&backlight>;
+
panel-info {
ac-bias = <255>;
ac-bias-intrpt = <0>;
diff --git a/drivers/gpu/drm/tilcdc/tilcdc_panel.c b/drivers/gpu/drm/tilcdc/tilcdc_panel.c
index c716c12..3dcf08e 100644
--- a/drivers/gpu/drm/tilcdc/tilcdc_panel.c
+++ b/drivers/gpu/drm/tilcdc/tilcdc_panel.c
@@ -342,7 +342,7 @@ static struct tilcdc_panel_info *of_get_panel_info(struct device_node *np)
static int panel_probe(struct platform_device *pdev)
{
- struct device_node *node = pdev->dev.of_node;
+ struct device_node *bl_node, *node = pdev->dev.of_node;
struct panel_module *panel_mod;
struct tilcdc_module *mod;
struct pinctrl *pinctrl;
@@ -358,6 +358,17 @@ static int panel_probe(struct platform_device *pdev)
if (!panel_mod)
return -ENOMEM;
+ bl_node = of_parse_phandle(node, "backlight", 0);
+ if (bl_node) {
+ panel_mod->backlight = of_find_backlight_by_node(bl_node);
+ of_node_put(bl_node);
+
+ if (!panel_mod->backlight)
+ return -EPROBE_DEFER;
+
+ dev_info(&pdev->dev, "found backlight\n");
+ }
+
mod = &panel_mod->base;
pdev->dev.platform_data = mod;
@@ -381,10 +392,6 @@ static int panel_probe(struct platform_device *pdev)
mod->preferred_bpp = panel_mod->info->bpp;
- panel_mod->backlight = of_find_backlight_by_node(node);
- if (panel_mod->backlight)
- dev_info(&pdev->dev, "found backlight\n");
-
return 0;
fail_timings:
@@ -392,6 +399,8 @@ fail_timings:
fail_free:
tilcdc_module_cleanup(mod);
+ if (panel_mod->backlight)
+ put_device(&panel_mod->backlight->dev);
return ret;
}
@@ -399,6 +408,10 @@ static int panel_remove(struct platform_device *pdev)
{
struct tilcdc_module *mod = dev_get_platdata(&pdev->dev);
struct panel_module *panel_mod = to_panel_module(mod);
+ struct backlight_device *backlight = panel_mod->backlight;
+
+ if (backlight)
+ put_device(&backlight->dev);
display_timings_release(panel_mod->timings);
--
1.9.1
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