[PATCH v3 1/2] drm/mediatek: Add gamma correction

Bibby Hsieh bibby.hsieh at mediatek.com
Wed Jul 20 20:23:00 PDT 2016


Hi, CK

I'm appreciate your comments.

On Fri, 2016-07-15 at 17:11 +0800, CK Hu wrote:
> Hi, Bibby:
> 
> Some comments inline.
> 
> On Thu, 2016-07-07 at 15:37 +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 at mediatek.com>
> > ---
> >  drivers/gpu/drm/mediatek/mtk_drm_crtc.c     |    8 +++
> >  drivers/gpu/drm/mediatek/mtk_drm_crtc.h     |    1 +
> >  drivers/gpu/drm/mediatek/mtk_drm_ddp_comp.c |   89 ++++++++++++++++++++++++++-
> >  drivers/gpu/drm/mediatek/mtk_drm_ddp_comp.h |   10 +++
> >  4 files changed, 106 insertions(+), 2 deletions(-)
> > 
> > diff --git a/drivers/gpu/drm/mediatek/mtk_drm_crtc.c b/drivers/gpu/drm/mediatek/mtk_drm_crtc.c
> > index 24aa3ba..ee219bb 100644
> > --- a/drivers/gpu/drm/mediatek/mtk_drm_crtc.c
> > +++ b/drivers/gpu/drm/mediatek/mtk_drm_crtc.c
> > @@ -409,6 +409,10 @@ static void mtk_drm_crtc_atomic_flush(struct drm_crtc *crtc,
> >  	}
> >  	if (pending_planes)
> >  		mtk_crtc->pending_planes = true;
> > +	if (crtc->state->color_mgmt_changed)
> > +		for (i = 0; i < mtk_crtc->ddp_comp_nr; i++)
> > +			mtk_ddp_gamma_set(mtk_crtc->ddp_comp[i], crtc->state);
> > +
> >  }
> >  
> >  static const struct drm_crtc_funcs mtk_crtc_funcs = {
> > @@ -418,6 +422,7 @@ 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		= drm_atomic_helper_legacy_gamma_set,
> >  };
> >  
> >  static const struct drm_crtc_helper_funcs mtk_crtc_helper_funcs = {
> > @@ -569,6 +574,9 @@ 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);
> > +	drm_helper_crtc_enable_color_mgmt(&mtk_crtc->base, MTK_LUT_SIZE,
> > +					  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..56c5894 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 +39,21 @@
> >  #define DISP_COLOR_WIDTH			0x0c50
> >  #define DISP_COLOR_HEIGHT			0x0c54
> >  
> > +#define DISP_AAL_EN				0x000
> > +#define DISP_AAL_SIZE				0x030
> > +
> > +#define DISP_GAMMA_EN				0x000
> > +#define DISP_GAMMA_CFG				0x020
> > +#define DISP_GAMMA_SIZE				0x030
> > +#define DISP_GAMMA_LUT				0x700
> 
> It's better that the digits of register address of OD, COLOR, AAL, and
> GAMMA are the same. Maybe you can align all to 4 digits.
> 
Ok, will fix.
> > +
> > +#define LUT_10BIT_MASK				0x3ff
> > +
> > +#define AAL_EN			BIT(0)
> > +
> > +#define GAMMA_EN		BIT(0)
> > +#define GAMMA_LUT_EN		BIT(1)
> > +
> >  #define	OD_RELAY_MODE		BIT(0)
> >  
> >  #define	UFO_BYPASS		BIT(2)
> > @@ -76,6 +92,61 @@ 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);
> > +}
> 
> I think AAL is somewhat different from GAMMA and this patch include 3
> modifications:
> 
> 1. AAL basic config
> 2. GAMMA basic config
> 3. Add gamma function of AAL and GAMMA
> 
> So you should split this patch into 3 patches.
> 
Ok, I will split that.
> > +
> > +static void mtk_gamma_config(struct mtk_ddp_comp *comp, unsigned int w,
> > +			     unsigned int h, unsigned int vrefresh)
> > +{
> > +	writel(h << 16 | w, comp->regs + DISP_GAMMA_SIZE);
> > +}
> > +
> > +static void mtk_gamma_start(struct mtk_ddp_comp *comp)
> > +{
> > +	writel(GAMMA_EN, comp->regs  + DISP_GAMMA_EN);
> > +}
> > +
> > +static void mtk_gamma_stop(struct mtk_ddp_comp *comp)
> > +{
> > +	writel_relaxed(0x0, comp->regs  + DISP_GAMMA_EN);
> > +}
> > +
> > +static void mtk_gamma_set(struct mtk_ddp_comp *comp,
> > +			  struct drm_crtc_state *state)
> > +{
> > +	unsigned int i, reg;
> > +	struct drm_color_lut *lut;
> > +	void __iomem *lut_base;
> > +	u32 word;
> > +
> > +	if (state->gamma_lut) {
> > +		reg = readl(comp->regs + DISP_GAMMA_CFG);
> > +		reg = reg | GAMMA_LUT_EN;
> > +		writel(reg, comp->regs + DISP_GAMMA_CFG);
> > +		lut_base = comp->regs + DISP_GAMMA_LUT;
> > +		lut = (struct drm_color_lut *)state->gamma_lut->data;
> > +		for (i = 0; i < MTK_LUT_SIZE; i++) {
> > +			word = (((lut[i].red >> 6) & LUT_10BIT_MASK) << 20) +
> > +			      (((lut[i].green >> 6) & LUT_10BIT_MASK) << 10) +
> > +			      ((lut[i].blue >> 6) & LUT_10BIT_MASK);
> > +			writel(word, (lut_base + i * 4));
> > +		}
> > +	}
> > +}
> > +
> >  static const struct mtk_ddp_comp_funcs ddp_color = {
> >  	.config = mtk_color_config,
> >  	.start = mtk_color_start,
> > @@ -90,6 +161,20 @@ 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 struct mtk_ddp_comp_funcs ddp_gamma = {
> > +	.gamma_set = mtk_gamma_set,
> > +	.config = mtk_gamma_config,
> > +	.start = mtk_gamma_start,
> > +	.stop = mtk_gamma_stop,
> > +};
> > +
> >  static const char * const mtk_ddp_comp_stem[MTK_DDP_COMP_TYPE_MAX] = {
> >  	[MTK_DISP_OVL] = "ovl",
> >  	[MTK_DISP_RDMA] = "rdma",
> > @@ -112,13 +197,13 @@ 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 },
> >  	[DDP_COMPONENT_DSI0]	= { MTK_DSI,		0, NULL },
> >  	[DDP_COMPONENT_DSI1]	= { MTK_DSI,		1, NULL },
> > -	[DDP_COMPONENT_GAMMA]	= { MTK_DISP_GAMMA,	0, NULL },
> > +	[DDP_COMPONENT_GAMMA]	= { MTK_DISP_GAMMA,	0, &ddp_gamma },
> >  	[DDP_COMPONENT_OD]	= { MTK_DISP_OD,	0, &ddp_od },
> >  	[DDP_COMPONENT_OVL0]	= { MTK_DISP_OVL,	0, NULL },
> >  	[DDP_COMPONENT_OVL1]	= { MTK_DISP_OVL,	1, 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..07e17fe 100644
> > --- a/drivers/gpu/drm/mediatek/mtk_drm_ddp_comp.h
> > +++ b/drivers/gpu/drm/mediatek/mtk_drm_ddp_comp.h
> > @@ -20,6 +20,7 @@ struct device;
> >  struct device_node;
> >  struct drm_crtc;
> >  struct drm_device;
> > +struct drm_crtc_state;
> >  struct mtk_plane_state;
> >  
> >  enum mtk_ddp_comp_type {
> > @@ -73,6 +74,8 @@ 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,
> > +			  struct drm_crtc_state *state);
> >  };
> >  
> >  struct mtk_ddp_comp {
> > @@ -139,6 +142,13 @@ 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,
> > +				     struct drm_crtc_state *state)
> > +{
> > +	if (comp->funcs && comp->funcs->gamma_set)
> > +		comp->funcs->gamma_set(comp, state);
> > +}
> > +
> >  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,
> 
> 





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