1 files changed, 52 insertions, 0 deletions

diff --git a/drivers/gpu/drm/sun4i/sun4i_tcon.c b/drivers/gpu/drm/sun4i/sun4i_tcon.c
index 0d6c5ed44795..1a114e380f13 100644
--- a/drivers/gpu/drm/sun4i/sun4i_tcon.c
+++ b/drivers/gpu/drm/sun4i/sun4i_tcon.c
@@ -17,6 +17,7 @@
 #include <drm/drm_encoder.h>
 #include <drm/drm_modes.h>
 #include <drm/drm_of.h>
+#include <drm/drm_panel.h>
 
 #include <uapi/drm/drm_mode.h>
 
@@ -343,6 +344,9 @@ static void sun4i_tcon0_mode_set_lvds(struct sun4i_tcon *tcon,
 static void sun4i_tcon0_mode_set_rgb(struct sun4i_tcon *tcon,
 				     const struct drm_display_mode *mode)
 {
+	struct drm_panel *panel = tcon->panel;
+	struct drm_connector *connector = panel->connector;
+	struct drm_display_info display_info = connector->display_info;
 	unsigned int bp, hsync, vsync;
 	u8 clk_delay;
 	u32 val = 0;
@@ -400,6 +404,27 @@ static void sun4i_tcon0_mode_set_rgb(struct sun4i_tcon *tcon,
 	if (mode->flags & DRM_MODE_FLAG_PVSYNC)
 		val |= SUN4I_TCON0_IO_POL_VSYNC_POSITIVE;
 
+	/*
+	 * On A20 and similar SoCs, the only way to achieve Positive Edge
+	 * (Rising Edge), is setting dclk clock phase to 2/3(240°).
+	 * By default TCON works in Negative Edge(Falling Edge),
+	 * this is why phase is set to 0 in that case.
+	 * Unfortunately there's no way to logically invert dclk through
+	 * IO_POL register.
+	 * The only acceptable way to work, triple checked with scope,
+	 * is using clock phase set to 0° for Negative Edge and set to 240°
+	 * for Positive Edge.
+	 * On A33 and similar SoCs there would be a 90° phase option,
+	 * but it divides also dclk by 2.
+	 * Following code is a way to avoid quirks all around TCON
+	 * and DOTCLOCK drivers.
+	 */
+	if (display_info.bus_flags & DRM_BUS_FLAG_PIXDATA_POSEDGE)
+		clk_set_phase(tcon->dclk, 240);
+
+	if (display_info.bus_flags & DRM_BUS_FLAG_PIXDATA_NEGEDGE)
+		clk_set_phase(tcon->dclk, 0);
+
 	regmap_update_bits(tcon->regs, SUN4I_TCON0_IO_POL_REG,
 			   SUN4I_TCON0_IO_POL_HSYNC_POSITIVE | SUN4I_TCON0_IO_POL_VSYNC_POSITIVE,
 			   val);
@@ -850,6 +875,7 @@ static int sun4i_tcon_bind(struct device *dev, struct device *master,
 	struct sunxi_engine *engine;
 	struct device_node *remote;
 	struct sun4i_tcon *tcon;
+	struct reset_control *edp_rstc;
 	bool has_lvds_rst, has_lvds_alt, can_lvds;
 	int ret;
 
@@ -874,6 +900,20 @@ static int sun4i_tcon_bind(struct device *dev, struct device *master,
 		return PTR_ERR(tcon->lcd_rst);
 	}
 
+	if (tcon->quirks->needs_edp_reset) {
+		edp_rstc = devm_reset_control_get_shared(dev, "edp");
+		if (IS_ERR(edp_rstc)) {
+			dev_err(dev, "Couldn't get edp reset line\n");
+			return PTR_ERR(edp_rstc);
+		}
+
+		ret = reset_control_deassert(edp_rstc);
+		if (ret) {
+			dev_err(dev, "Couldn't deassert edp reset line\n");
+			return ret;
+		}
+	}
+
 	/* Make sure our TCON is reset */
 	ret = reset_control_reset(tcon->lcd_rst);
 	if (ret) {
@@ -1166,6 +1206,16 @@ static const struct sun4i_tcon_quirks sun8i_v3s_quirks = {
 	.has_channel_0		= true,
 };
 
+static const struct sun4i_tcon_quirks sun9i_a80_tcon_lcd_quirks = {
+	.has_channel_0	= true,
+	.needs_edp_reset = true,
+};
+
+static const struct sun4i_tcon_quirks sun9i_a80_tcon_tv_quirks = {
+	.has_channel_1	= true,
+	.needs_edp_reset = true,
+};
+
 /* sun4i_drv uses this list to check if a device node is a TCON */
 const struct of_device_id sun4i_tcon_of_table[] = {
 	{ .compatible = "allwinner,sun4i-a10-tcon", .data = &sun4i_a10_quirks },
@@ -1177,6 +1227,8 @@ const struct of_device_id sun4i_tcon_of_table[] = {
 	{ .compatible = "allwinner,sun8i-a83t-tcon-lcd", .data = &sun8i_a83t_lcd_quirks },
 	{ .compatible = "allwinner,sun8i-a83t-tcon-tv", .data = &sun8i_a83t_tv_quirks },
 	{ .compatible = "allwinner,sun8i-v3s-tcon", .data = &sun8i_v3s_quirks },
+	{ .compatible = "allwinner,sun9i-a80-tcon-lcd", .data = &sun9i_a80_tcon_lcd_quirks },
+	{ .compatible = "allwinner,sun9i-a80-tcon-tv", .data = &sun9i_a80_tcon_tv_quirks },
 	{ }
 };
 MODULE_DEVICE_TABLE(of, sun4i_tcon_of_table);