drm/ingenic: Fix support for JZ4780 HDMI output

We have to make sure that
- JZ_LCD_OSDC_ALPHAEN is set
- plane f0 is disabled as it's not working yet

Tested on MIPS Creator CI20 board.
Signed-off-by: Paul Boddie <paul@boddie.org.uk>
Signed-off-by: Ezequiel Garcia <ezequiel@collabora.com>
Signed-off-by: H. Nikolaus Schaller <hns@goldelico.com>
Fixes: ef2f5d0a ("drm/ingenic: prepare ingenic drm for later addition of JZ4780")
Signed-off-by: Paul Cercueil <paul@crapouillou.net>
[pcercuei: add proper fixes commit, slightly reword commit description]
Link: https://patchwork.freedesktop.org/patch/msgid/9d3a2000d2bb014f1afb0613537bdc523202135d.1644681054.git.hns@goldelico.com

drivers/gpu/drm/ingenic/ingenic-drm-drv.c

@@ -65,8 +65,10 @@ struct ingenic_dma_hwdescs {
 struct jz_soc_info {
 	bool needs_dev_clk;
 	bool has_osd;
+	bool has_alpha;
 	bool map_noncoherent;
 	bool use_extended_hwdesc;
+	bool plane_f0_not_working;
 	unsigned int max_width, max_height;
 	const u32 *formats_f0, *formats_f1;
 	unsigned int num_formats_f0, num_formats_f1;
@@ -453,7 +455,7 @@ static int ingenic_drm_plane_atomic_check(struct drm_plane *plane,
 	if (!crtc)
 		return 0;
 
-	if (plane == &priv->f0)
+	if (priv->soc_info->plane_f0_not_working && plane == &priv->f0)
 		return -EINVAL;
 
 	crtc_state = drm_atomic_get_existing_crtc_state(state,
@@ -1055,6 +1057,7 @@ static int ingenic_drm_bind(struct device *dev, bool has_components)
 	long parent_rate;
 	unsigned int i, clone_mask = 0;
 	int ret, irq;
+	u32 osdc = 0;
 
 	soc_info = of_device_get_match_data(dev);
 	if (!soc_info) {
@@ -1312,7 +1315,10 @@ static int ingenic_drm_bind(struct device *dev, bool has_components)
 
 	/* Enable OSD if available */
 	if (soc_info->has_osd)
-		regmap_write(priv->map, JZ_REG_LCD_OSDC, JZ_LCD_OSDC_OSDEN);
+		osdc |= JZ_LCD_OSDC_OSDEN;
+	if (soc_info->has_alpha)
+		osdc |= JZ_LCD_OSDC_ALPHAEN;
+	regmap_write(priv->map, JZ_REG_LCD_OSDC, osdc);
 
 	mutex_init(&priv->clk_mutex);
 	priv->clock_nb.notifier_call = ingenic_drm_update_pixclk;
@@ -1511,7 +1517,9 @@ static const struct jz_soc_info jz4770_soc_info = {
 static const struct jz_soc_info jz4780_soc_info = {
 	.needs_dev_clk = true,
 	.has_osd = true,
+	.has_alpha = true,
 	.use_extended_hwdesc = true,
+	.plane_f0_not_working = true,	/* REVISIT */
 	.max_width = 4096,
 	.max_height = 2048,
 	.formats_f1 = jz4770_formats_f1,