Re: [PATCH 1/2] drm/mediatek: Add gamma correction
From: Bibby Hsieh
Date: Wed Jun 15 2016 - 23:04:47 EST
Hi, Daniel,
Thank you for your suggestion, I will modify that to use the atomic
color management.
Bibby
On Tue, 2016-06-14 at 07:43 +0200, Daniel Vetter wrote:
> On Tue, Jun 14, 2016 at 10:55:52AM +0800, Bibby Hsieh wrote:
> > Apply gamma function to correct brightness values.
> > It applies arbitrary mapping curve to compensate the
> > incorrect transfer function of the panel.
> >
> > Signed-off-by: Bibby Hsieh <bibby.hsieh@xxxxxxxxxxxx>
>
> I think it would be much better to use the new atomic color management
> support, which includes gamma. See drm_crtc_enable_color_mgmt.
> -Daniel
>
> > ---
> > drivers/gpu/drm/mediatek/mtk_drm_crtc.c | 12 ++++++
> > drivers/gpu/drm/mediatek/mtk_drm_crtc.h | 1 +
> > drivers/gpu/drm/mediatek/mtk_drm_ddp_comp.c | 56 ++++++++++++++++++++++++++-
> > drivers/gpu/drm/mediatek/mtk_drm_ddp_comp.h | 9 +++++
> > 4 files changed, 77 insertions(+), 1 deletion(-)
> >
> > diff --git a/drivers/gpu/drm/mediatek/mtk_drm_crtc.c b/drivers/gpu/drm/mediatek/mtk_drm_crtc.c
> > index 24aa3ba..1b38406 100644
> > --- a/drivers/gpu/drm/mediatek/mtk_drm_crtc.c
> > +++ b/drivers/gpu/drm/mediatek/mtk_drm_crtc.c
> > @@ -127,6 +127,16 @@ static void mtk_drm_crtc_reset(struct drm_crtc *crtc)
> > state->base.crtc = crtc;
> > }
> >
> > +static void mtk_crtc_gamma_set(struct drm_crtc *crtc, u16 *r,
> > + u16 *g, u16 *b, uint32_t start, uint32_t size)
> > +{
> > + struct mtk_drm_crtc *mtk_crtc = to_mtk_crtc(crtc);
> > + unsigned int i;
> > +
> > + for (i = 0; i < mtk_crtc->ddp_comp_nr; i++)
> > + mtk_ddp_gamma_set(mtk_crtc->ddp_comp[i], r, g, b, start, size);
> > +}
> > +
> > static struct drm_crtc_state *mtk_drm_crtc_duplicate_state(struct drm_crtc *crtc)
> > {
> > struct mtk_crtc_state *state;
> > @@ -418,6 +428,7 @@ static const struct drm_crtc_funcs mtk_crtc_funcs = {
> > .reset = mtk_drm_crtc_reset,
> > .atomic_duplicate_state = mtk_drm_crtc_duplicate_state,
> > .atomic_destroy_state = mtk_drm_crtc_destroy_state,
> > + .gamma_set = mtk_crtc_gamma_set,
> > };
> >
> > static const struct drm_crtc_helper_funcs mtk_crtc_helper_funcs = {
> > @@ -569,6 +580,7 @@ int mtk_drm_crtc_create(struct drm_device *drm_dev,
> > if (ret < 0)
> > goto unprepare;
> >
> > + drm_mode_crtc_set_gamma_size(&mtk_crtc->base, MTK_LUT_SIZE);
> > priv->crtc[pipe] = &mtk_crtc->base;
> > priv->num_pipes++;
> >
> > diff --git a/drivers/gpu/drm/mediatek/mtk_drm_crtc.h b/drivers/gpu/drm/mediatek/mtk_drm_crtc.h
> > index 81e5566..d332564 100644
> > --- a/drivers/gpu/drm/mediatek/mtk_drm_crtc.h
> > +++ b/drivers/gpu/drm/mediatek/mtk_drm_crtc.h
> > @@ -19,6 +19,7 @@
> > #include "mtk_drm_plane.h"
> >
> > #define OVL_LAYER_NR 4
> > +#define MTK_LUT_SIZE 512
> >
> > int mtk_drm_crtc_enable_vblank(struct drm_device *drm, unsigned int pipe);
> > void mtk_drm_crtc_disable_vblank(struct drm_device *drm, unsigned int pipe);
> > diff --git a/drivers/gpu/drm/mediatek/mtk_drm_ddp_comp.c b/drivers/gpu/drm/mediatek/mtk_drm_ddp_comp.c
> > index 3970fcf..3fd5141 100644
> > --- a/drivers/gpu/drm/mediatek/mtk_drm_ddp_comp.c
> > +++ b/drivers/gpu/drm/mediatek/mtk_drm_ddp_comp.c
> > @@ -24,6 +24,7 @@
> > #include "mtk_drm_drv.h"
> > #include "mtk_drm_plane.h"
> > #include "mtk_drm_ddp_comp.h"
> > +#include "mtk_drm_crtc.h"
> >
> > #define DISP_OD_EN 0x0000
> > #define DISP_OD_INTEN 0x0008
> > @@ -38,6 +39,18 @@
> > #define DISP_COLOR_WIDTH 0x0c50
> > #define DISP_COLOR_HEIGHT 0x0c54
> >
> > +#define DISP_AAL_EN 0x000
> > +#define DISP_AAL_SIZE 0x030
> > +
> > +#define DISP_GAMMA_CFG 0x020
> > +#define DISP_GAMMA_LUT 0x700
> > +
> > +#define LUT_10BIT_MASK 0x3ff
> > +
> > +#define AAL_EN BIT(0)
> > +
> > +#define GAMMA_LUT_EN BIT(1)
> > +
> > #define OD_RELAY_MODE BIT(0)
> >
> > #define UFO_BYPASS BIT(2)
> > @@ -76,6 +89,40 @@ static void mtk_ufoe_start(struct mtk_ddp_comp *comp)
> > writel(UFO_BYPASS, comp->regs + DISP_REG_UFO_START);
> > }
> >
> > +static void mtk_aal_config(struct mtk_ddp_comp *comp, unsigned int w,
> > + unsigned int h, unsigned int vrefresh)
> > +{
> > + writel(h << 16 | w, comp->regs + DISP_AAL_SIZE);
> > +}
> > +
> > +static void mtk_aal_start(struct mtk_ddp_comp *comp)
> > +{
> > + writel(AAL_EN, comp->regs + DISP_AAL_EN);
> > +}
> > +
> > +static void mtk_aal_stop(struct mtk_ddp_comp *comp)
> > +{
> > + writel_relaxed(0x0, comp->regs + DISP_AAL_EN);
> > +}
> > +
> > +static void mtk_gamma_set(struct mtk_ddp_comp *comp, u16 *r, u16 *g,
> > + u16 *b, uint32_t start, uint32_t size)
> > +{
> > + int i;
> > + unsigned int lut;
> > + int end = (start + size > MTK_LUT_SIZE) ? MTK_LUT_SIZE : start + size;
> > + void __iomem *lut_base;
> > +
> > + writel(GAMMA_LUT_EN, comp->regs + DISP_GAMMA_CFG);
> > + lut_base = comp->regs + DISP_GAMMA_LUT;
> > + for (i = start; i < end; i++) {
> > + lut = (((r[i] >> 6) & LUT_10BIT_MASK) << 20) +
> > + (((g[i] >> 6) & LUT_10BIT_MASK) << 10) +
> > + ((b[i] >> 6) & LUT_10BIT_MASK);
> > + writel(lut, (lut_base + i * 4));
> > + }
> > +}
> > +
> > static const struct mtk_ddp_comp_funcs ddp_color = {
> > .config = mtk_color_config,
> > .start = mtk_color_start,
> > @@ -90,6 +137,13 @@ static const struct mtk_ddp_comp_funcs ddp_ufoe = {
> > .start = mtk_ufoe_start,
> > };
> >
> > +static const struct mtk_ddp_comp_funcs ddp_aal = {
> > + .gamma_set = mtk_gamma_set,
> > + .config = mtk_aal_config,
> > + .start = mtk_aal_start,
> > + .stop = mtk_aal_stop,
> > +};
> > +
> > static const char * const mtk_ddp_comp_stem[MTK_DDP_COMP_TYPE_MAX] = {
> > [MTK_DISP_OVL] = "ovl",
> > [MTK_DISP_RDMA] = "rdma",
> > @@ -112,7 +166,7 @@ struct mtk_ddp_comp_match {
> > };
> >
> > static const struct mtk_ddp_comp_match mtk_ddp_matches[DDP_COMPONENT_ID_MAX] = {
> > - [DDP_COMPONENT_AAL] = { MTK_DISP_AAL, 0, NULL },
> > + [DDP_COMPONENT_AAL] = { MTK_DISP_AAL, 0, &ddp_aal },
> > [DDP_COMPONENT_COLOR0] = { MTK_DISP_COLOR, 0, &ddp_color },
> > [DDP_COMPONENT_COLOR1] = { MTK_DISP_COLOR, 1, &ddp_color },
> > [DDP_COMPONENT_DPI0] = { MTK_DPI, 0, NULL },
> > diff --git a/drivers/gpu/drm/mediatek/mtk_drm_ddp_comp.h b/drivers/gpu/drm/mediatek/mtk_drm_ddp_comp.h
> > index 6b13ba9..0832179 100644
> > --- a/drivers/gpu/drm/mediatek/mtk_drm_ddp_comp.h
> > +++ b/drivers/gpu/drm/mediatek/mtk_drm_ddp_comp.h
> > @@ -73,6 +73,8 @@ struct mtk_ddp_comp_funcs {
> > void (*layer_off)(struct mtk_ddp_comp *comp, unsigned int idx);
> > void (*layer_config)(struct mtk_ddp_comp *comp, unsigned int idx,
> > struct mtk_plane_state *state);
> > + void (*gamma_set)(struct mtk_ddp_comp *comp, u16 *r, u16 *g, u16 *b,
> > + u32 start, u32 size);
> > };
> >
> > struct mtk_ddp_comp {
> > @@ -139,6 +141,13 @@ static inline void mtk_ddp_comp_layer_config(struct mtk_ddp_comp *comp,
> > comp->funcs->layer_config(comp, idx, state);
> > }
> >
> > +static inline void mtk_ddp_gamma_set(struct mtk_ddp_comp *comp, u16 *r, u16 *g,
> > + u16 *b, uint32_t start, uint32_t size)
> > +{
> > + if (comp->funcs && comp->funcs->gamma_set)
> > + comp->funcs->gamma_set(comp, r, g, b, start, size);
> > +}
> > +
> > int mtk_ddp_comp_get_id(struct device_node *node,
> > enum mtk_ddp_comp_type comp_type);
> > int mtk_ddp_comp_init(struct device *dev, struct device_node *comp_node,
> > --
> > 1.7.9.5
> >
>