DRM: ingenic: Add support for Sharp panels

Add support for the LCD panels that must be driven with the
Sharp-specific signals SPL, CLS, REV, PS.

An example of such panel is the LS020B1DD01D supported by the
panel-simple DRM panel driver.
Signed-off-by: Paul Cercueil <paul@crapouillou.net>
Link: https://patchwork.freedesktop.org/patch/msgid/20190627182114.27299-2-paul@crapouillou.net
# *** extracted tags ***
Reviewed-by: Sam Ravnborg <sam@ravnborg.org>

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

@@ -166,6 +166,8 @@ struct ingenic_drm {
 
 	struct ingenic_dma_hwdesc *dma_hwdesc;
 	dma_addr_t dma_hwdesc_phys;
+
+	bool panel_is_sharp;
 };
 
 static const u32 ingenic_drm_primary_formats[] = {
@@ -283,6 +285,13 @@ static void ingenic_drm_crtc_update_timings(struct ingenic_drm *priv,
 	regmap_write(priv->map, JZ_REG_LCD_DAV,
 		     vds << JZ_LCD_DAV_VDS_OFFSET |
 		     vde << JZ_LCD_DAV_VDE_OFFSET);
+
+	if (priv->panel_is_sharp) {
+		regmap_write(priv->map, JZ_REG_LCD_PS, hde << 16 | (hde + 1));
+		regmap_write(priv->map, JZ_REG_LCD_CLS, hde << 16 | (hde + 1));
+		regmap_write(priv->map, JZ_REG_LCD_SPL, hpe << 16 | (hpe + 1));
+		regmap_write(priv->map, JZ_REG_LCD_REV, mode->htotal << 16);
+	}
 }
 
 static void ingenic_drm_crtc_update_ctrl(struct ingenic_drm *priv,
@@ -378,11 +387,18 @@ static void ingenic_drm_encoder_atomic_mode_set(struct drm_encoder *encoder,
 {
 	struct ingenic_drm *priv = drm_encoder_get_priv(encoder);
 	struct drm_display_mode *mode = &crtc_state->adjusted_mode;
-	struct drm_display_info *info = &conn_state->connector->display_info;
-	unsigned int cfg = JZ_LCD_CFG_PS_DISABLE
-			 | JZ_LCD_CFG_CLS_DISABLE
-			 | JZ_LCD_CFG_SPL_DISABLE
-			 | JZ_LCD_CFG_REV_DISABLE;
+	struct drm_connector *conn = conn_state->connector;
+	struct drm_display_info *info = &conn->display_info;
+	unsigned int cfg;
+
+	priv->panel_is_sharp = info->bus_flags & DRM_BUS_FLAG_SHARP_SIGNALS;
+
+	if (priv->panel_is_sharp) {
+		cfg = JZ_LCD_CFG_MODE_SPECIAL_TFT_1 | JZ_LCD_CFG_REV_POLARITY;
+	} else {
+		cfg = JZ_LCD_CFG_PS_DISABLE | JZ_LCD_CFG_CLS_DISABLE
+		    | JZ_LCD_CFG_SPL_DISABLE | JZ_LCD_CFG_REV_DISABLE;
+	}
 
 	if (mode->flags & DRM_MODE_FLAG_NHSYNC)
 		cfg |= JZ_LCD_CFG_HSYNC_ACTIVE_LOW;
@@ -393,7 +409,8 @@ static void ingenic_drm_encoder_atomic_mode_set(struct drm_encoder *encoder,
 	if (info->bus_flags & DRM_BUS_FLAG_PIXDATA_NEGEDGE)
 		cfg |= JZ_LCD_CFG_PCLK_FALLING_EDGE;
 
-	if (conn_state->connector->connector_type == DRM_MODE_CONNECTOR_TV) {
+	if (!priv->panel_is_sharp) {
+		if (conn->connector_type == DRM_MODE_CONNECTOR_TV) {
 			if (mode->flags & DRM_MODE_FLAG_INTERLACE)
 				cfg |= JZ_LCD_CFG_MODE_TV_OUT_I;
 			else
@@ -413,6 +430,7 @@ static void ingenic_drm_encoder_atomic_mode_set(struct drm_encoder *encoder,
 				break;
 			}
 		}
+	}
 
 	regmap_write(priv->map, JZ_REG_LCD_CFG, cfg);
 }