diff options
| author | Bibby Hsieh <bibby.hsieh@mediatek.com> | 2016-07-28 10:22:55 +0800 |
|---|---|---|
| committer | Philipp Zabel <p.zabel@pengutronix.de> | 2016-08-11 10:52:23 +0200 |
| commit | 7216436420414144646f5d8343d061355fd23483 (patch) | |
| tree | 2c165aea9b4c7272e46114182f2d85412acd643d /drivers/gpu/drm/mediatek/mtk_disp_ovl.c | |
| parent | 2f3f4dda747c0619594d13996e65598ab675c60c (diff) | |
drm/mediatek: set mt8173 dithering function
Some panels only accept bpc (bit per color) 6-bit.
But, the default bpc in mt8173 display data path is 8-bit.
If we didn't enable dithering function to convert bpc,
display cannot show the smooth grayscale image.
In mt8173, the dithering function in OD (OverDrive) and
GAMMA module, we have to config them with
connector->display_mode.bpc when CRTC initial.
1. Clear the default value at *_DITHER_5 and *_DITHER_7 register.
2. Calculate the LSB_ERR_SHIFT bits and ADD_LSHIFT bits two values.
i.e. Input bpc of OD is 10 bits, we assume the bpc of panel is 6-bit,
so, we need to set 4-bit to LSB_ERR_SHIFT and ADD_LSHIFT bits respectively.
3. Then, set the OD or GAMMA to dithering mode depends on path-1 or path-2.
Signed-off-by: Bibby Hsieh <bibby.hsieh@mediatek.com>
Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>
Diffstat (limited to 'drivers/gpu/drm/mediatek/mtk_disp_ovl.c')
| -rw-r--r-- | drivers/gpu/drm/mediatek/mtk_disp_ovl.c | 3 |
1 files changed, 2 insertions, 1 deletions
diff --git a/drivers/gpu/drm/mediatek/mtk_disp_ovl.c b/drivers/gpu/drm/mediatek/mtk_disp_ovl.c index 8f62671fcfbf..019b7ca392d7 100644 --- a/drivers/gpu/drm/mediatek/mtk_disp_ovl.c +++ b/drivers/gpu/drm/mediatek/mtk_disp_ovl.c @@ -103,7 +103,8 @@ static void mtk_ovl_stop(struct mtk_ddp_comp *comp) } static void mtk_ovl_config(struct mtk_ddp_comp *comp, unsigned int w, - unsigned int h, unsigned int vrefresh) + unsigned int h, unsigned int vrefresh, + unsigned int bpc) { if (w != 0 && h != 0) writel_relaxed(h << 16 | w, comp->regs + DISP_REG_OVL_ROI_SIZE); |