drm: bridge: icn6211: Fix HFP_HSW_HBP_HI and HFP_MIN handling

[ Upstream commit c0ff7a6 ]

The HFP_HSW_HBP_HI register must be programmed with 2 LSbits of each
Horizontal Front Porch/Sync/Back Porch. Currently the driver programs
this register to 0, which breaks displays with either value above 255.

The HFP_MIN register must be set to the same value as HFP_LI, otherwise
there is visible image distortion, usually in the form of missing lines
at the bottom of the panel.

Fix this by correctly programming the HFP_HSW_HBP_HI and HFP_MIN registers.

Acked-by: Maxime Ripard <[email protected]>
Fixes: ce517f1 ("drm: bridge: Add Chipone ICN6211 MIPI-DSI to RGB bridge")
Signed-off-by: Marek Vasut <[email protected]>
Cc: Jagan Teki <[email protected]>
Cc: Maxime Ripard <[email protected]>
Cc: Robert Foss <[email protected]>
Cc: Sam Ravnborg <[email protected]>
Cc: Thomas Zimmermann <[email protected]>
To: [email protected]
Signed-off-by: Robert Foss <[email protected]>
Link: https://patchwork.freedesktop.org/patch/msgid/[email protected]
Signed-off-by: Sasha Levin <[email protected]>

drivers/gpu/drm/bridge/chipone-icn6211.c

@@ -34,6 +34,9 @@
 #define HSYNC_LI		0x24
 #define HBP_LI			0x25
 #define HFP_HSW_HBP_HI		0x26
+#define HFP_HSW_HBP_HI_HFP(n)		(((n) & 0x300) >> 4)
+#define HFP_HSW_HBP_HI_HS(n)		(((n) & 0x300) >> 6)
+#define HFP_HSW_HBP_HI_HBP(n)		(((n) & 0x300) >> 8)
 #define VFP			0x27
 #define VSYNC			0x28
 #define VBP			0x29
@@ -165,6 +168,7 @@ static void chipone_enable(struct drm_bridge *bridge)
 {
 	struct chipone *icn = bridge_to_chipone(bridge);
 	struct drm_display_mode *mode = bridge_to_mode(bridge);
+	u16 hfp, hbp, hsync;
 
 	ICN6211_DSI(icn, MIPI_CFG_PW, MIPI_CFG_PW_CONFIG_DSI);
 
@@ -180,13 +184,18 @@ static void chipone_enable(struct drm_bridge *bridge)
 		    ((mode->hdisplay >> 8) & 0xf) |
 		    (((mode->vdisplay >> 8) & 0xf) << 4));
 
-	ICN6211_DSI(icn, HFP_LI, mode->hsync_start - mode->hdisplay);
+	hfp = mode->hsync_start - mode->hdisplay;
+	hsync = mode->hsync_end - mode->hsync_start;
+	hbp = mode->htotal - mode->hsync_end;
 
-	ICN6211_DSI(icn, HSYNC_LI, mode->hsync_end - mode->hsync_start);
-
-	ICN6211_DSI(icn, HBP_LI, mode->htotal - mode->hsync_end);
-
-	ICN6211_DSI(icn, HFP_HSW_HBP_HI, 0x00);
+	ICN6211_DSI(icn, HFP_LI, hfp & 0xff);
+	ICN6211_DSI(icn, HSYNC_LI, hsync & 0xff);
+	ICN6211_DSI(icn, HBP_LI, hbp & 0xff);
+	/* Top two bits of Horizontal Front porch/Sync/Back porch */
+	ICN6211_DSI(icn, HFP_HSW_HBP_HI,
+		    HFP_HSW_HBP_HI_HFP(hfp) |
+		    HFP_HSW_HBP_HI_HS(hsync) |
+		    HFP_HSW_HBP_HI_HBP(hbp));
 
 	ICN6211_DSI(icn, VFP, mode->vsync_start - mode->vdisplay);
 
@@ -196,7 +205,7 @@ static void chipone_enable(struct drm_bridge *bridge)
 
 	/* dsi specific sequence */
 	ICN6211_DSI(icn, SYNC_EVENT_DLY, 0x80);
-	ICN6211_DSI(icn, HFP_MIN, 0x28);
+	ICN6211_DSI(icn, HFP_MIN, hfp & 0xff);
 	ICN6211_DSI(icn, MIPI_PD_CK_LANE, 0xa0);
 	ICN6211_DSI(icn, PLL_CTRL(12), 0xff);
 	ICN6211_DSI(icn, BIST_POL, BIST_POL_DE_POL);