[PATCH v4 3/3] drm/mediatek: fix the wrong pixel clock when resolution is 4K

From: Bibby Hsieh
Date: Wed Aug 17 2016 - 02:58:21 EST


From: Junzhi Zhao <junzhi.zhao@xxxxxxxxxxxx>

Pixel clock should be 297MHz when resolution is 4K.

Signed-off-by: Junzhi Zhao <junzhi.zhao@xxxxxxxxxxxx>
Signed-off-by: Bibby Hsieh <bibby.hsieh@xxxxxxxxxxxx>
---
drivers/gpu/drm/mediatek/mtk_dpi.c | 9 +++++++--
1 file changed, 7 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/mediatek/mtk_dpi.c b/drivers/gpu/drm/mediatek/mtk_dpi.c
index 0186e50..90fb831 100644
--- a/drivers/gpu/drm/mediatek/mtk_dpi.c
+++ b/drivers/gpu/drm/mediatek/mtk_dpi.c
@@ -432,11 +432,16 @@ static int mtk_dpi_set_display_mode(struct mtk_dpi *dpi,
unsigned long pll_rate;
unsigned int factor;

+ /* let pll_rate can fix the valid range of tvdpll (1G~2GHz) */
pix_rate = 1000UL * mode->clock;
- if (mode->clock <= 74000)
+ if (mode->clock <= 27000)
+ factor = 16 * 3;
+ else if (mode->clock <= 84000)
factor = 8 * 3;
- else
+ else if (mode->clock <= 167000)
factor = 4 * 3;
+ else
+ factor = 2 * 3;
pll_rate = pix_rate * factor;

dev_dbg(dpi->dev, "Want PLL %lu Hz, pixel clock %lu Hz\n",
--
1.7.9.5