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authorJunzhi Zhao <junzhi.zhao@mediatek.com>2016-09-29 11:02:15 +0800
committerCK Hu <ck.hu@mediatek.com>2016-10-19 09:07:08 +0800
commit0d2200794f0a2c1ebb3b6613842914d8ce4b67f9 (patch)
treee872f270f260e84c4cacde3e93a957708f9f274d /drivers/gpu
parent968253bd7caae5621f6806dd5055353fe33d366e (diff)
drm/mediatek: modify the factor to make the pll_rate set in the 1G-2G range
Currently, the code sets the "pll" to the desired multiple of the pixel clock manully(4*3m 8*3,etc). The valid range of the pll is 1G-2G, however, when the pixel clock is bigger than 167MHz, the "pll" will be set to a invalid value( > 2G), then the "pll" will be 2GHz, thus the pixel clock will be in correct. Change the factor to make the "pll" be set in the (1G, 2G) range. Signed-off-by: Junzhi Zhao <junzhi.zhao@mediatek.com> Signed-off-by: Bibby Hsieh <bibby.hsieh@mediatek.com>
Diffstat (limited to 'drivers/gpu')
-rw-r--r--drivers/gpu/drm/mediatek/mtk_dpi.c9
1 files changed, 7 insertions, 2 deletions
diff --git a/drivers/gpu/drm/mediatek/mtk_dpi.c b/drivers/gpu/drm/mediatek/mtk_dpi.c
index 0186e500d2a5..90fb831ef031 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",