[PATCH 4/6] drm/bridge: tc358767: fix timing calculations

Andrey Gusakov andrey.gusakov at cogentembedded.com
Thu Jul 27 12:47:34 UTC 2017


Fields in HTIM01 and HTIM02 regs should be even.
Recomended thresh_dly value is max_tu_symbol.

Signed-off-by: Andrey Gusakov <andrey.gusakov at cogentembedded.com>
---
 drivers/gpu/drm/bridge/tc358767.c | 34 ++++++++++++++++++++--------------
 1 file changed, 20 insertions(+), 14 deletions(-)

diff --git a/drivers/gpu/drm/bridge/tc358767.c b/drivers/gpu/drm/bridge/tc358767.c
index 4aee6178d889..c657a00af508 100644
--- a/drivers/gpu/drm/bridge/tc358767.c
+++ b/drivers/gpu/drm/bridge/tc358767.c
@@ -659,6 +659,14 @@ static int tc_set_video_mode(struct tc_data *tc, struct drm_display_mode *mode)
 	int lower_margin = mode->vsync_start - mode->vdisplay;
 	int vsync_len = mode->vsync_end - mode->vsync_start;
 
+	/*
+	 * Recommended maximum number of symbols transferred in a transfer unit:
+	 * DIV_ROUND_UP((input active video bandwidth in bytes) * tu_size,
+	 *              (output active video bandwidth in bytes))
+	 * Must be less than tu_size.
+	 */
+	max_tu_symbol = TU_SIZE_RECOMMENDED - 1;
+
 	dev_dbg(tc->dev, "set mode %dx%d\n",
 		mode->hdisplay, mode->vdisplay);
 	dev_dbg(tc->dev, "H margin %d,%d sync %d\n",
@@ -668,13 +676,18 @@ static int tc_set_video_mode(struct tc_data *tc, struct drm_display_mode *mode)
 	dev_dbg(tc->dev, "total: %dx%d\n", mode->htotal, mode->vtotal);
 
 
-	/* LCD Ctl Frame Size */
-	tc_write(VPCTRL0, (0x40 << 20) /* VSDELAY */ |
+	/*
+	 * LCD Ctl Frame Size
+	 * datasheet is not clear of vsdelay in case of DPI
+	 * assume we do not need any delay when DPI is a source of
+	 * sync signals
+	 */
+	tc_write(VPCTRL0, (0 << 20) /* VSDELAY */ |
 		 OPXLFMT_RGB888 | FRMSYNC_DISABLED | MSF_DISABLED);
-	tc_write(HTIM01, (left_margin << 16) |		/* H back porch */
-			 (hsync_len << 0));		/* Hsync */
-	tc_write(HTIM02, (right_margin << 16) |		/* H front porch */
-			 (mode->hdisplay << 0));	/* width */
+	tc_write(HTIM01, (ALIGN(left_margin, 2) << 16) | /* H back porch */
+			 (ALIGN(hsync_len, 2) << 0));	 /* Hsync */
+	tc_write(HTIM02, (ALIGN(right_margin, 2) << 16) |  /* H front porch */
+			 (ALIGN(mode->hdisplay, 2) << 0)); /* width */
 	tc_write(VTIM01, (upper_margin << 16) |		/* V back porch */
 			 (vsync_len << 0));		/* Vsync */
 	tc_write(VTIM02, (lower_margin << 16) |		/* V front porch */
@@ -693,7 +706,7 @@ static int tc_set_video_mode(struct tc_data *tc, struct drm_display_mode *mode)
 	/* DP Main Stream Attributes */
 	vid_sync_dly = hsync_len + left_margin + mode->hdisplay;
 	tc_write(DP0_VIDSYNCDELAY,
-		 (0x003e << 16) |	/* thresh_dly */
+		 (max_tu_symbol << 16) |	/* thresh_dly */
 		 (vid_sync_dly << 0));
 
 	tc_write(DP0_TOTALVAL, (mode->vtotal << 16) | (mode->htotal));
@@ -709,13 +722,6 @@ static int tc_set_video_mode(struct tc_data *tc, struct drm_display_mode *mode)
 	tc_write(DPIPXLFMT, VS_POL_ACTIVE_LOW | HS_POL_ACTIVE_LOW |
 		 DE_POL_ACTIVE_HIGH | SUB_CFG_TYPE_CONFIG1 | DPI_BPP_RGB888);
 
-	/*
-	 * Recommended maximum number of symbols transferred in a transfer unit:
-	 * DIV_ROUND_UP((input active video bandwidth in bytes) * tu_size,
-	 *              (output active video bandwidth in bytes))
-	 * Must be less than tu_size.
-	 */
-	max_tu_symbol = TU_SIZE_RECOMMENDED - 1;
 	tc_write(DP0_MISC, (max_tu_symbol << 23) | (TU_SIZE_RECOMMENDED << 16) |
 			   BPC_8);
 
-- 
2.13.0



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