gpu:drm:tilcdc: get preferred_bpp value from DT

The preferred_bpp value in currently hard-coded to 16.
This causes color corruption on the am335x-evm lcd panel which
requires 32 bpp instead. This changes attempts to use the configured
bpp value from the DT or built-in panel-info struct.
Signed-off-by: Benoit Parrot <bparrot@ti.com>
Acked-by: Rob Clark <robdclark@gmail.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>

drivers/gpu/drm/tilcdc/tilcdc_drv.c

@@ -157,7 +157,9 @@ static int tilcdc_load(struct drm_device *dev, unsigned long flags)
 	struct platform_device *pdev = dev->platformdev;
 	struct device_node *node = pdev->dev.of_node;
 	struct tilcdc_drm_private *priv;
+	struct tilcdc_module *mod;
 	struct resource *res;
+	u32 bpp = 0;
 	int ret;
 
 	priv = kzalloc(sizeof(*priv), GFP_KERNEL);
@@ -256,7 +258,15 @@ static int tilcdc_load(struct drm_device *dev, unsigned long flags)
 
 	platform_set_drvdata(pdev, dev);
 
-	priv->fbdev = drm_fbdev_cma_init(dev, 16,
+
+	list_for_each_entry(mod, &module_list, list) {
+		DBG("%s: preferred_bpp: %d", mod->name, mod->preferred_bpp);
+		bpp = mod->preferred_bpp;
+		if (bpp > 0)
+			break;
+	}
+
+	priv->fbdev = drm_fbdev_cma_init(dev, bpp,
 			dev->mode_config.num_crtc,
 			dev->mode_config.num_connector);
 

drivers/gpu/drm/tilcdc/tilcdc_drv.h

@@ -89,6 +89,7 @@ struct tilcdc_module {
 	const char *name;
 	struct list_head list;
 	const struct tilcdc_module_ops *funcs;
+	unsigned int preferred_bpp;
 };
 
 void tilcdc_module_init(struct tilcdc_module *mod, const char *name,

drivers/gpu/drm/tilcdc/tilcdc_panel.c

@@ -393,6 +393,8 @@ static int panel_probe(struct platform_device *pdev)
 		goto fail;
 	}
 
+	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");

drivers/gpu/drm/tilcdc/tilcdc_slave.c

@@ -323,6 +323,8 @@ static int slave_probe(struct platform_device *pdev)
 		goto fail;
 	}
 
+	mod->preferred_bpp = slave_info.bpp;
+
 	i2c_node = of_find_node_by_phandle(i2c_phandle);
 	if (!i2c_node) {
 		dev_err(&pdev->dev, "could not get i2c bus node\n");

drivers/gpu/drm/tilcdc/tilcdc_tfp410.c

@@ -354,6 +354,8 @@ static int tfp410_probe(struct platform_device *pdev)
 		goto fail;
 	}
 
+	mod->preferred_bpp = dvi_info.bpp;
+
 	i2c_node = of_find_node_by_phandle(i2c_phandle);
 	if (!i2c_node) {
 		dev_err(&pdev->dev, "could not get i2c bus node\n");