[PATCH v4 00/11] MediaTek DDP GAMMA - 12-bit LUT support

[PATCH v4 00/11] MediaTek DDP GAMMA - 12-bit LUT support

[AngeloGioacchino Del Regno]

Changes in v4:
 - Fixed assignment typo appeared in v3

Changes in v3:
 - Fixed issues due to variables renaming during cleanup (oops)
 - This is actually the right series, since v2 was taken from the
   wrong kernel tree.... :-)

Changes in v2:
 - Added explicit inclusion of linux/bitfield.h in patch [06/11]

This series adds support for GAMMA IP requiring and/or supporting
a 12-bits LUT using a slightly different register layout and programming
sequence for multiple LUT banks: this IP version is currently found
on a number of SoCs, not only including the Chromebook/IoT oriented
Kompanio 1200/1380 MT8195/MT8195T, but also Smartphone chips such as
the Dimensity 9200 (MT6985) and others.

This series was tested on MT8195, MT8192, MT8173, MT6795:
 * MT6795, MT8192, MT8173: No regression, works fine.
 * MT8195: Color correction is finally working!

AngeloGioacchino Del Regno (10):
  drm/mediatek: gamma: Reduce indentation in mtk_gamma_set_common()
  drm/mediatek: gamma: Support SoC specific LUT size
  drm/mediatek: gamma: Improve and simplify HW LUT calculation
  drm/mediatek: gamma: Enable the Gamma LUT table only after programming
  drm/mediatek: gamma: Use bitfield macros
  drm/mediatek: gamma: Support specifying number of bits per LUT
    component
  drm/mediatek: gamma: Support multi-bank gamma LUT
  drm/mediatek: gamma: Add support for 12-bit LUT and MT8195
  drm/mediatek: gamma: Make sure relay mode is disabled
  drm/mediatek: gamma: Program gamma LUT type for descending or rising

Jason-JH.Lin (1):
  drm/mediatek: gamma: Adjust mtk_drm_gamma_set_common parameters

 drivers/gpu/drm/mediatek/mtk_disp_aal.c     |   2 +-
 drivers/gpu/drm/mediatek/mtk_disp_drv.h     |   3 +-
 drivers/gpu/drm/mediatek/mtk_disp_gamma.c   | 197 +++++++++++++++++---
 drivers/gpu/drm/mediatek/mtk_drm_crtc.c     |   4 +-
 drivers/gpu/drm/mediatek/mtk_drm_crtc.h     |   1 -
 drivers/gpu/drm/mediatek/mtk_drm_ddp_comp.c |   1 +
 drivers/gpu/drm/mediatek/mtk_drm_ddp_comp.h |   9 +
 7 files changed, 181 insertions(+), 36 deletions(-)

-- 
2.40.1

[PATCH v4 01/11] drm/mediatek: gamma: Adjust mtk_drm_gamma_set_common parameters

[AngeloGioacchino Del Regno]

From: "Jason-JH.Lin" <jason-jh.lin@mediatek.com>

Adjust the parameters in mtk_drm_gamma_set_common()
  - add (struct device *dev) to get lut_diff from gamma's driver data
  - remove (bool lut_diff) and use false as default value in the function

Signed-off-by: Jason-JH.Lin <jason-jh.lin@mediatek.com>
Signed-off-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
---
 drivers/gpu/drm/mediatek/mtk_disp_aal.c   |  2 +-
 drivers/gpu/drm/mediatek/mtk_disp_drv.h   |  2 +-
 drivers/gpu/drm/mediatek/mtk_disp_gamma.c | 15 +++++++++------
 3 files changed, 11 insertions(+), 8 deletions(-)

diff --git a/drivers/gpu/drm/mediatek/mtk_disp_aal.c b/drivers/gpu/drm/mediatek/mtk_disp_aal.c
index 434e8a9ce8ab..8ddf7a97e583 100644
--- a/drivers/gpu/drm/mediatek/mtk_disp_aal.c
+++ b/drivers/gpu/drm/mediatek/mtk_disp_aal.c
@@ -67,7 +67,7 @@ void mtk_aal_gamma_set(struct device *dev, struct drm_crtc_state *state)
 	struct mtk_disp_aal *aal = dev_get_drvdata(dev);
 
 	if (aal->data && aal->data->has_gamma)
-		mtk_gamma_set_common(aal->regs, state, false);
+		mtk_gamma_set_common(NULL, aal->regs, state);
 }
 
 void mtk_aal_start(struct device *dev)
diff --git a/drivers/gpu/drm/mediatek/mtk_disp_drv.h b/drivers/gpu/drm/mediatek/mtk_disp_drv.h
index 2254038519e1..75045932353e 100644
--- a/drivers/gpu/drm/mediatek/mtk_disp_drv.h
+++ b/drivers/gpu/drm/mediatek/mtk_disp_drv.h
@@ -54,7 +54,7 @@ void mtk_gamma_config(struct device *dev, unsigned int w,
 		      unsigned int h, unsigned int vrefresh,
 		      unsigned int bpc, struct cmdq_pkt *cmdq_pkt);
 void mtk_gamma_set(struct device *dev, struct drm_crtc_state *state);
-void mtk_gamma_set_common(void __iomem *regs, struct drm_crtc_state *state, bool lut_diff);
+void mtk_gamma_set_common(struct device *dev, void __iomem *regs, struct drm_crtc_state *state);
 void mtk_gamma_start(struct device *dev);
 void mtk_gamma_stop(struct device *dev);
 
diff --git a/drivers/gpu/drm/mediatek/mtk_disp_gamma.c b/drivers/gpu/drm/mediatek/mtk_disp_gamma.c
index c844942603f7..99be515a941b 100644
--- a/drivers/gpu/drm/mediatek/mtk_disp_gamma.c
+++ b/drivers/gpu/drm/mediatek/mtk_disp_gamma.c
@@ -55,14 +55,21 @@ void mtk_gamma_clk_disable(struct device *dev)
 	clk_disable_unprepare(gamma->clk);
 }
 
-void mtk_gamma_set_common(void __iomem *regs, struct drm_crtc_state *state, bool lut_diff)
+void mtk_gamma_set_common(struct device *dev, void __iomem *regs, struct drm_crtc_state *state)
 {
+	struct mtk_disp_gamma *gamma = dev_get_drvdata(dev);
 	unsigned int i, reg;
 	struct drm_color_lut *lut;
 	void __iomem *lut_base;
+	bool lut_diff;
 	u32 word;
 	u32 diff[3] = {0};
 
+	if (gamma && gamma->data)
+		lut_diff = gamma->data->lut_diff;
+	else
+		lut_diff = false;
+
 	if (state->gamma_lut) {
 		reg = readl(regs + DISP_GAMMA_CFG);
 		reg = reg | GAMMA_LUT_EN;
@@ -92,12 +99,8 @@ void mtk_gamma_set_common(void __iomem *regs, struct drm_crtc_state *state, bool
 void mtk_gamma_set(struct device *dev, struct drm_crtc_state *state)
 {
 	struct mtk_disp_gamma *gamma = dev_get_drvdata(dev);
-	bool lut_diff = false;
-
-	if (gamma->data)
-		lut_diff = gamma->data->lut_diff;
 
-	mtk_gamma_set_common(gamma->regs, state, lut_diff);
+	mtk_gamma_set_common(dev, gamma->regs, state);
 }
 
 void mtk_gamma_config(struct device *dev, unsigned int w,
-- 
2.40.1

[PATCH v4 02/11] drm/mediatek: gamma: Reduce indentation in mtk_gamma_set_common()

[AngeloGioacchino Del Regno]

Invert the check for state->gamma_lut and move it at the beginning
of the function to reduce indentation: this prepares the code for
keeping readability on later additions.

This commit brings no functional changes.

Signed-off-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Reviewed-by: Jason-JH.Lin <jason-jh.lin@mediatek.com>
---
 drivers/gpu/drm/mediatek/mtk_disp_gamma.c | 45 ++++++++++++-----------
 1 file changed, 23 insertions(+), 22 deletions(-)

diff --git a/drivers/gpu/drm/mediatek/mtk_disp_gamma.c b/drivers/gpu/drm/mediatek/mtk_disp_gamma.c
index 99be515a941b..ce6f2499b891 100644
--- a/drivers/gpu/drm/mediatek/mtk_disp_gamma.c
+++ b/drivers/gpu/drm/mediatek/mtk_disp_gamma.c
@@ -65,34 +65,35 @@ void mtk_gamma_set_common(struct device *dev, void __iomem *regs, struct drm_crt
 	u32 word;
 	u32 diff[3] = {0};
 
+	/* If there's no gamma lut there's nothing to do here. */
+	if (!state->gamma_lut)
+		return;
+
 	if (gamma && gamma->data)
 		lut_diff = gamma->data->lut_diff;
 	else
 		lut_diff = false;
 
-	if (state->gamma_lut) {
-		reg = readl(regs + DISP_GAMMA_CFG);
-		reg = reg | GAMMA_LUT_EN;
-		writel(reg, regs + DISP_GAMMA_CFG);
-		lut_base = regs + DISP_GAMMA_LUT;
-		lut = (struct drm_color_lut *)state->gamma_lut->data;
-		for (i = 0; i < MTK_LUT_SIZE; i++) {
-
-			if (!lut_diff || (i % 2 == 0)) {
-				word = (((lut[i].red >> 6) & LUT_10BIT_MASK) << 20) +
-					(((lut[i].green >> 6) & LUT_10BIT_MASK) << 10) +
-					((lut[i].blue >> 6) & LUT_10BIT_MASK);
-			} else {
-				diff[0] = (lut[i].red >> 6) - (lut[i - 1].red >> 6);
-				diff[1] = (lut[i].green >> 6) - (lut[i - 1].green >> 6);
-				diff[2] = (lut[i].blue >> 6) - (lut[i - 1].blue >> 6);
-
-				word = ((diff[0] & LUT_10BIT_MASK) << 20) +
-					((diff[1] & LUT_10BIT_MASK) << 10) +
-					(diff[2] & LUT_10BIT_MASK);
-			}
-			writel(word, (lut_base + i * 4));
+	reg = readl(regs + DISP_GAMMA_CFG);
+	reg = reg | GAMMA_LUT_EN;
+	writel(reg, regs + DISP_GAMMA_CFG);
+	lut_base = regs + DISP_GAMMA_LUT;
+	lut = (struct drm_color_lut *)state->gamma_lut->data;
+	for (i = 0; i < MTK_LUT_SIZE; i++) {
+		if (!lut_diff || (i % 2 == 0)) {
+			word = (((lut[i].red >> 6) & LUT_10BIT_MASK) << 20) +
+				(((lut[i].green >> 6) & LUT_10BIT_MASK) << 10) +
+				((lut[i].blue >> 6) & LUT_10BIT_MASK);
+		} else {
+			diff[0] = (lut[i].red >> 6) - (lut[i - 1].red >> 6);
+			diff[1] = (lut[i].green >> 6) - (lut[i - 1].green >> 6);
+			diff[2] = (lut[i].blue >> 6) - (lut[i - 1].blue >> 6);
+
+			word = ((diff[0] & LUT_10BIT_MASK) << 20) +
+				((diff[1] & LUT_10BIT_MASK) << 10) +
+				(diff[2] & LUT_10BIT_MASK);
 		}
+		writel(word, (lut_base + i * 4));
 	}
 }
 
-- 
2.40.1

[PATCH v4 03/11] drm/mediatek: gamma: Support SoC specific LUT size

[AngeloGioacchino Del Regno]

Newer SoCs support a bigger Gamma LUT table: wire up a callback
to retrieve the correct LUT size for each different Gamma IP.

Co-developed-by: Jason-JH.Lin <jason-jh.lin@mediatek.com>
Signed-off-by: Jason-JH.Lin <jason-jh.lin@mediatek.com>
[Angelo: Rewritten commit message/description + porting]
Signed-off-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Reviewed-by: Jason-JH.Lin <jason-jh.lin@mediatek.com>
---
 drivers/gpu/drm/mediatek/mtk_disp_drv.h     |  1 +
 drivers/gpu/drm/mediatek/mtk_disp_gamma.c   | 25 ++++++++++++++++++---
 drivers/gpu/drm/mediatek/mtk_drm_crtc.c     |  4 ++--
 drivers/gpu/drm/mediatek/mtk_drm_crtc.h     |  1 -
 drivers/gpu/drm/mediatek/mtk_drm_ddp_comp.c |  1 +
 drivers/gpu/drm/mediatek/mtk_drm_ddp_comp.h |  9 ++++++++
 6 files changed, 35 insertions(+), 6 deletions(-)

diff --git a/drivers/gpu/drm/mediatek/mtk_disp_drv.h b/drivers/gpu/drm/mediatek/mtk_disp_drv.h
index 75045932353e..e554b19f4830 100644
--- a/drivers/gpu/drm/mediatek/mtk_disp_drv.h
+++ b/drivers/gpu/drm/mediatek/mtk_disp_drv.h
@@ -53,6 +53,7 @@ void mtk_gamma_clk_disable(struct device *dev);
 void mtk_gamma_config(struct device *dev, unsigned int w,
 		      unsigned int h, unsigned int vrefresh,
 		      unsigned int bpc, struct cmdq_pkt *cmdq_pkt);
+unsigned int mtk_gamma_get_lut_size(struct device *dev);
 void mtk_gamma_set(struct device *dev, struct drm_crtc_state *state);
 void mtk_gamma_set_common(struct device *dev, void __iomem *regs, struct drm_crtc_state *state);
 void mtk_gamma_start(struct device *dev);
diff --git a/drivers/gpu/drm/mediatek/mtk_disp_gamma.c b/drivers/gpu/drm/mediatek/mtk_disp_gamma.c
index ce6f2499b891..d194d9bc2e2b 100644
--- a/drivers/gpu/drm/mediatek/mtk_disp_gamma.c
+++ b/drivers/gpu/drm/mediatek/mtk_disp_gamma.c
@@ -25,10 +25,12 @@
 #define DISP_GAMMA_LUT				0x0700
 
 #define LUT_10BIT_MASK				0x03ff
+#define LUT_SIZE_DEFAULT			512 /* for setting gamma lut from AAL */
 
 struct mtk_disp_gamma_data {
 	bool has_dither;
 	bool lut_diff;
+	u16 lut_size;
 };
 
 /*
@@ -55,6 +57,17 @@ void mtk_gamma_clk_disable(struct device *dev)
 	clk_disable_unprepare(gamma->clk);
 }
 
+unsigned int mtk_gamma_get_lut_size(struct device *dev)
+{
+	struct mtk_disp_gamma *gamma = dev_get_drvdata(dev);
+	unsigned int lut_size = LUT_SIZE_DEFAULT;
+
+	if (gamma && gamma->data)
+		lut_size = gamma->data->lut_size;
+
+	return lut_size;
+}
+
 void mtk_gamma_set_common(struct device *dev, void __iomem *regs, struct drm_crtc_state *state)
 {
 	struct mtk_disp_gamma *gamma = dev_get_drvdata(dev);
@@ -62,6 +75,7 @@ void mtk_gamma_set_common(struct device *dev, void __iomem *regs, struct drm_crt
 	struct drm_color_lut *lut;
 	void __iomem *lut_base;
 	bool lut_diff;
+	u16 lut_size;
 	u32 word;
 	u32 diff[3] = {0};
 
@@ -69,17 +83,20 @@ void mtk_gamma_set_common(struct device *dev, void __iomem *regs, struct drm_crt
 	if (!state->gamma_lut)
 		return;
 
-	if (gamma && gamma->data)
+	if (gamma && gamma->data) {
 		lut_diff = gamma->data->lut_diff;
-	else
+		lut_size = gamma->data->lut_size;
+	} else {
 		lut_diff = false;
+		lut_size = LUT_SIZE_DEFAULT;
+	}
 
 	reg = readl(regs + DISP_GAMMA_CFG);
 	reg = reg | GAMMA_LUT_EN;
 	writel(reg, regs + DISP_GAMMA_CFG);
 	lut_base = regs + DISP_GAMMA_LUT;
 	lut = (struct drm_color_lut *)state->gamma_lut->data;
-	for (i = 0; i < MTK_LUT_SIZE; i++) {
+	for (i = 0; i < lut_size; i++) {
 		if (!lut_diff || (i % 2 == 0)) {
 			word = (((lut[i].red >> 6) & LUT_10BIT_MASK) << 20) +
 				(((lut[i].green >> 6) & LUT_10BIT_MASK) << 10) +
@@ -196,10 +213,12 @@ static int mtk_disp_gamma_remove(struct platform_device *pdev)
 
 static const struct mtk_disp_gamma_data mt8173_gamma_driver_data = {
 	.has_dither = true,
+	.lut_size = 512,
 };
 
 static const struct mtk_disp_gamma_data mt8183_gamma_driver_data = {
 	.lut_diff = true,
+	.lut_size = 512,
 };
 
 static const struct of_device_id mtk_disp_gamma_driver_dt_match[] = {
diff --git a/drivers/gpu/drm/mediatek/mtk_drm_crtc.c b/drivers/gpu/drm/mediatek/mtk_drm_crtc.c
index d40142842f85..0df62b076f49 100644
--- a/drivers/gpu/drm/mediatek/mtk_drm_crtc.c
+++ b/drivers/gpu/drm/mediatek/mtk_drm_crtc.c
@@ -958,8 +958,8 @@ int mtk_drm_crtc_create(struct drm_device *drm_dev,
 		mtk_crtc->ddp_comp[i] = comp;
 
 		if (comp->funcs) {
-			if (comp->funcs->gamma_set)
-				gamma_lut_size = MTK_LUT_SIZE;
+			if (comp->funcs->gamma_set && comp->funcs->gamma_get_lut_size)
+				gamma_lut_size = mtk_ddp_gamma_get_lut_size(comp);
 
 			if (comp->funcs->ctm_set)
 				has_ctm = true;
diff --git a/drivers/gpu/drm/mediatek/mtk_drm_crtc.h b/drivers/gpu/drm/mediatek/mtk_drm_crtc.h
index 3e9046993d09..b2e50292e57d 100644
--- a/drivers/gpu/drm/mediatek/mtk_drm_crtc.h
+++ b/drivers/gpu/drm/mediatek/mtk_drm_crtc.h
@@ -10,7 +10,6 @@
 #include "mtk_drm_ddp_comp.h"
 #include "mtk_drm_plane.h"
 
-#define MTK_LUT_SIZE	512
 #define MTK_MAX_BPC	10
 #define MTK_MIN_BPC	3
 
diff --git a/drivers/gpu/drm/mediatek/mtk_drm_ddp_comp.c b/drivers/gpu/drm/mediatek/mtk_drm_ddp_comp.c
index f114da4d36a9..c77af2e4000f 100644
--- a/drivers/gpu/drm/mediatek/mtk_drm_ddp_comp.c
+++ b/drivers/gpu/drm/mediatek/mtk_drm_ddp_comp.c
@@ -322,6 +322,7 @@ static const struct mtk_ddp_comp_funcs ddp_dsi = {
 static const struct mtk_ddp_comp_funcs ddp_gamma = {
 	.clk_enable = mtk_gamma_clk_enable,
 	.clk_disable = mtk_gamma_clk_disable,
+	.gamma_get_lut_size = mtk_gamma_get_lut_size,
 	.gamma_set = mtk_gamma_set,
 	.config = mtk_gamma_config,
 	.start = mtk_gamma_start,
diff --git a/drivers/gpu/drm/mediatek/mtk_drm_ddp_comp.h b/drivers/gpu/drm/mediatek/mtk_drm_ddp_comp.h
index febcaeef16a1..c1355960e195 100644
--- a/drivers/gpu/drm/mediatek/mtk_drm_ddp_comp.h
+++ b/drivers/gpu/drm/mediatek/mtk_drm_ddp_comp.h
@@ -67,6 +67,7 @@ struct mtk_ddp_comp_funcs {
 	void (*layer_config)(struct device *dev, unsigned int idx,
 			     struct mtk_plane_state *state,
 			     struct cmdq_pkt *cmdq_pkt);
+	unsigned int (*gamma_get_lut_size)(struct device *dev);
 	void (*gamma_set)(struct device *dev,
 			  struct drm_crtc_state *state);
 	void (*bgclr_in_on)(struct device *dev);
@@ -186,6 +187,14 @@ static inline void mtk_ddp_comp_layer_config(struct mtk_ddp_comp *comp,
 		comp->funcs->layer_config(comp->dev, idx, state, cmdq_pkt);
 }
 
+static inline unsigned int mtk_ddp_gamma_get_lut_size(struct mtk_ddp_comp *comp)
+{
+	if (comp->funcs && comp->funcs->gamma_get_lut_size)
+		return comp->funcs->gamma_get_lut_size(comp->dev);
+
+	return 0;
+}
+
 static inline void mtk_ddp_gamma_set(struct mtk_ddp_comp *comp,
 				     struct drm_crtc_state *state)
 {
-- 
2.40.1

Re: [PATCH v4 03/11] drm/mediatek: gamma: Support SoC specific LUT size

[CK Hu (胡俊光)]

Hi, Angelo:

On Thu, 2023-05-18 at 12:48 +0200, AngeloGioacchino Del Regno wrote:
> External email : Please do not click links or open attachments until
> you have verified the sender or the content.
> 
> 
> Newer SoCs support a bigger Gamma LUT table: wire up a callback
> to retrieve the correct LUT size for each different Gamma IP.
> 
> Co-developed-by: Jason-JH.Lin <jason-jh.lin@mediatek.com>
> Signed-off-by: Jason-JH.Lin <jason-jh.lin@mediatek.com>
> [Angelo: Rewritten commit message/description + porting]
> Signed-off-by: AngeloGioacchino Del Regno <
> angelogioacchino.delregno@collabora.com>
> Reviewed-by: Jason-JH.Lin <jason-jh.lin@mediatek.com>
> ---
>  drivers/gpu/drm/mediatek/mtk_disp_drv.h     |  1 +
>  drivers/gpu/drm/mediatek/mtk_disp_gamma.c   | 25 ++++++++++++++++++-
> --
>  drivers/gpu/drm/mediatek/mtk_drm_crtc.c     |  4 ++--
>  drivers/gpu/drm/mediatek/mtk_drm_crtc.h     |  1 -
>  drivers/gpu/drm/mediatek/mtk_drm_ddp_comp.c |  1 +
>  drivers/gpu/drm/mediatek/mtk_drm_ddp_comp.h |  9 ++++++++
>  6 files changed, 35 insertions(+), 6 deletions(-)
> 
> diff --git a/drivers/gpu/drm/mediatek/mtk_disp_drv.h
> b/drivers/gpu/drm/mediatek/mtk_disp_drv.h
> index 75045932353e..e554b19f4830 100644
> --- a/drivers/gpu/drm/mediatek/mtk_disp_drv.h
> +++ b/drivers/gpu/drm/mediatek/mtk_disp_drv.h
> @@ -53,6 +53,7 @@ void mtk_gamma_clk_disable(struct device *dev);
>  void mtk_gamma_config(struct device *dev, unsigned int w,
>                       unsigned int h, unsigned int vrefresh,
>                       unsigned int bpc, struct cmdq_pkt *cmdq_pkt);
> +unsigned int mtk_gamma_get_lut_size(struct device *dev);
>  void mtk_gamma_set(struct device *dev, struct drm_crtc_state
> *state);
>  void mtk_gamma_set_common(struct device *dev, void __iomem *regs,
> struct drm_crtc_state *state);
>  void mtk_gamma_start(struct device *dev);
> diff --git a/drivers/gpu/drm/mediatek/mtk_disp_gamma.c
> b/drivers/gpu/drm/mediatek/mtk_disp_gamma.c
> index ce6f2499b891..d194d9bc2e2b 100644
> --- a/drivers/gpu/drm/mediatek/mtk_disp_gamma.c
> +++ b/drivers/gpu/drm/mediatek/mtk_disp_gamma.c
> @@ -25,10 +25,12 @@
>  #define DISP_GAMMA_LUT                         0x0700
> 
>  #define LUT_10BIT_MASK                         0x03ff
> +#define LUT_SIZE_DEFAULT                       512 /* for setting
> gamma lut from AAL */

I would like to place AAL definition in AAL driver and pass it to gamma
driver.

Regards,
CK

> 
>  struct mtk_disp_gamma_data {
>         bool has_dither;
>         bool lut_diff;
> +       u16 lut_size;
>  };
> 
>  /*
> @@ -55,6 +57,17 @@ void mtk_gamma_clk_disable(struct device *dev)
>         clk_disable_unprepare(gamma->clk);
>  }
> 
> +unsigned int mtk_gamma_get_lut_size(struct device *dev)
> +{
> +       struct mtk_disp_gamma *gamma = dev_get_drvdata(dev);
> +       unsigned int lut_size = LUT_SIZE_DEFAULT;
> +
> +       if (gamma && gamma->data)
> +               lut_size = gamma->data->lut_size;
> +
> +       return lut_size;
> +}
> +
>  void mtk_gamma_set_common(struct device *dev, void __iomem *regs,
> struct drm_crtc_state *state)
>  {
>         struct mtk_disp_gamma *gamma = dev_get_drvdata(dev);
> @@ -62,6 +75,7 @@ void mtk_gamma_set_common(struct device *dev, void
> __iomem *regs, struct drm_crt
>         struct drm_color_lut *lut;
>         void __iomem *lut_base;
>         bool lut_diff;
> +       u16 lut_size;
>         u32 word;
>         u32 diff[3] = {0};
> 
> @@ -69,17 +83,20 @@ void mtk_gamma_set_common(struct device *dev,
> void __iomem *regs, struct drm_crt
>         if (!state->gamma_lut)
>                 return;
> 
> -       if (gamma && gamma->data)
> +       if (gamma && gamma->data) {
>                 lut_diff = gamma->data->lut_diff;
> -       else
> +               lut_size = gamma->data->lut_size;
> +       } else {
>                 lut_diff = false;
> +               lut_size = LUT_SIZE_DEFAULT;
> +       }
> 
>         reg = readl(regs + DISP_GAMMA_CFG);
>         reg = reg | GAMMA_LUT_EN;
>         writel(reg, regs + DISP_GAMMA_CFG);
>         lut_base = regs + DISP_GAMMA_LUT;
>         lut = (struct drm_color_lut *)state->gamma_lut->data;
> -       for (i = 0; i < MTK_LUT_SIZE; i++) {
> +       for (i = 0; i < lut_size; i++) {
>                 if (!lut_diff || (i % 2 == 0)) {
>                         word = (((lut[i].red >> 6) & LUT_10BIT_MASK)
> << 20) +
>                                 (((lut[i].green >> 6) &
> LUT_10BIT_MASK) << 10) +
> @@ -196,10 +213,12 @@ static int mtk_disp_gamma_remove(struct
> platform_device *pdev)
> 
>  static const struct mtk_disp_gamma_data mt8173_gamma_driver_data = {
>         .has_dither = true,
> +       .lut_size = 512,
>  };
> 
>  static const struct mtk_disp_gamma_data mt8183_gamma_driver_data = {
>         .lut_diff = true,
> +       .lut_size = 512,
>  };
> 
>  static const struct of_device_id mtk_disp_gamma_driver_dt_match[] =
> {
> diff --git a/drivers/gpu/drm/mediatek/mtk_drm_crtc.c
> b/drivers/gpu/drm/mediatek/mtk_drm_crtc.c
> index d40142842f85..0df62b076f49 100644
> --- a/drivers/gpu/drm/mediatek/mtk_drm_crtc.c
> +++ b/drivers/gpu/drm/mediatek/mtk_drm_crtc.c
> @@ -958,8 +958,8 @@ int mtk_drm_crtc_create(struct drm_device
> *drm_dev,
>                 mtk_crtc->ddp_comp[i] = comp;
> 
>                 if (comp->funcs) {
> -                       if (comp->funcs->gamma_set)
> -                               gamma_lut_size = MTK_LUT_SIZE;
> +                       if (comp->funcs->gamma_set && comp->funcs-
> >gamma_get_lut_size)
> +                               gamma_lut_size =
> mtk_ddp_gamma_get_lut_size(comp);
> 
>                         if (comp->funcs->ctm_set)
>                                 has_ctm = true;
> diff --git a/drivers/gpu/drm/mediatek/mtk_drm_crtc.h
> b/drivers/gpu/drm/mediatek/mtk_drm_crtc.h
> index 3e9046993d09..b2e50292e57d 100644
> --- a/drivers/gpu/drm/mediatek/mtk_drm_crtc.h
> +++ b/drivers/gpu/drm/mediatek/mtk_drm_crtc.h
> @@ -10,7 +10,6 @@
>  #include "mtk_drm_ddp_comp.h"
>  #include "mtk_drm_plane.h"
> 
> -#define MTK_LUT_SIZE   512
>  #define MTK_MAX_BPC    10
>  #define MTK_MIN_BPC    3
> 
> diff --git a/drivers/gpu/drm/mediatek/mtk_drm_ddp_comp.c
> b/drivers/gpu/drm/mediatek/mtk_drm_ddp_comp.c
> index f114da4d36a9..c77af2e4000f 100644
> --- a/drivers/gpu/drm/mediatek/mtk_drm_ddp_comp.c
> +++ b/drivers/gpu/drm/mediatek/mtk_drm_ddp_comp.c
> @@ -322,6 +322,7 @@ static const struct mtk_ddp_comp_funcs ddp_dsi =
> {
>  static const struct mtk_ddp_comp_funcs ddp_gamma = {
>         .clk_enable = mtk_gamma_clk_enable,
>         .clk_disable = mtk_gamma_clk_disable,
> +       .gamma_get_lut_size = mtk_gamma_get_lut_size,
>         .gamma_set = mtk_gamma_set,
>         .config = mtk_gamma_config,
>         .start = mtk_gamma_start,
> diff --git a/drivers/gpu/drm/mediatek/mtk_drm_ddp_comp.h
> b/drivers/gpu/drm/mediatek/mtk_drm_ddp_comp.h
> index febcaeef16a1..c1355960e195 100644
> --- a/drivers/gpu/drm/mediatek/mtk_drm_ddp_comp.h
> +++ b/drivers/gpu/drm/mediatek/mtk_drm_ddp_comp.h
> @@ -67,6 +67,7 @@ struct mtk_ddp_comp_funcs {
>         void (*layer_config)(struct device *dev, unsigned int idx,
>                              struct mtk_plane_state *state,
>                              struct cmdq_pkt *cmdq_pkt);
> +       unsigned int (*gamma_get_lut_size)(struct device *dev);
>         void (*gamma_set)(struct device *dev,
>                           struct drm_crtc_state *state);
>         void (*bgclr_in_on)(struct device *dev);
> @@ -186,6 +187,14 @@ static inline void
> mtk_ddp_comp_layer_config(struct mtk_ddp_comp *comp,
>                 comp->funcs->layer_config(comp->dev, idx, state,
> cmdq_pkt);
>  }
> 
> +static inline unsigned int mtk_ddp_gamma_get_lut_size(struct
> mtk_ddp_comp *comp)
> +{
> +       if (comp->funcs && comp->funcs->gamma_get_lut_size)
> +               return comp->funcs->gamma_get_lut_size(comp->dev);
> +
> +       return 0;
> +}
> +
>  static inline void mtk_ddp_gamma_set(struct mtk_ddp_comp *comp,
>                                      struct drm_crtc_state *state)
>  {
> --
> 2.40.1
> 

Re: [PATCH v4 03/11] drm/mediatek: gamma: Support SoC specific LUT size

[AngeloGioacchino Del Regno]

Il 26/05/23 07:20, CK Hu (胡俊光) ha scritto:
> Hi, Angelo:
> 
> On Thu, 2023-05-18 at 12:48 +0200, AngeloGioacchino Del Regno wrote:
>> External email : Please do not click links or open attachments until
>> you have verified the sender or the content.
>>
>>
>> Newer SoCs support a bigger Gamma LUT table: wire up a callback
>> to retrieve the correct LUT size for each different Gamma IP.
>>
>> Co-developed-by: Jason-JH.Lin <jason-jh.lin@mediatek.com>
>> Signed-off-by: Jason-JH.Lin <jason-jh.lin@mediatek.com>
>> [Angelo: Rewritten commit message/description + porting]
>> Signed-off-by: AngeloGioacchino Del Regno <
>> angelogioacchino.delregno@collabora.com>
>> Reviewed-by: Jason-JH.Lin <jason-jh.lin@mediatek.com>
>> ---
>>   drivers/gpu/drm/mediatek/mtk_disp_drv.h     |  1 +
>>   drivers/gpu/drm/mediatek/mtk_disp_gamma.c   | 25 ++++++++++++++++++-
>> --
>>   drivers/gpu/drm/mediatek/mtk_drm_crtc.c     |  4 ++--
>>   drivers/gpu/drm/mediatek/mtk_drm_crtc.h     |  1 -
>>   drivers/gpu/drm/mediatek/mtk_drm_ddp_comp.c |  1 +
>>   drivers/gpu/drm/mediatek/mtk_drm_ddp_comp.h |  9 ++++++++
>>   6 files changed, 35 insertions(+), 6 deletions(-)
>>
>> diff --git a/drivers/gpu/drm/mediatek/mtk_disp_drv.h
>> b/drivers/gpu/drm/mediatek/mtk_disp_drv.h
>> index 75045932353e..e554b19f4830 100644
>> --- a/drivers/gpu/drm/mediatek/mtk_disp_drv.h
>> +++ b/drivers/gpu/drm/mediatek/mtk_disp_drv.h
>> @@ -53,6 +53,7 @@ void mtk_gamma_clk_disable(struct device *dev);
>>   void mtk_gamma_config(struct device *dev, unsigned int w,
>>                        unsigned int h, unsigned int vrefresh,
>>                        unsigned int bpc, struct cmdq_pkt *cmdq_pkt);
>> +unsigned int mtk_gamma_get_lut_size(struct device *dev);
>>   void mtk_gamma_set(struct device *dev, struct drm_crtc_state
>> *state);
>>   void mtk_gamma_set_common(struct device *dev, void __iomem *regs,
>> struct drm_crtc_state *state);
>>   void mtk_gamma_start(struct device *dev);
>> diff --git a/drivers/gpu/drm/mediatek/mtk_disp_gamma.c
>> b/drivers/gpu/drm/mediatek/mtk_disp_gamma.c
>> index ce6f2499b891..d194d9bc2e2b 100644
>> --- a/drivers/gpu/drm/mediatek/mtk_disp_gamma.c
>> +++ b/drivers/gpu/drm/mediatek/mtk_disp_gamma.c
>> @@ -25,10 +25,12 @@
>>   #define DISP_GAMMA_LUT                         0x0700
>>
>>   #define LUT_10BIT_MASK                         0x03ff
>> +#define LUT_SIZE_DEFAULT                       512 /* for setting
>> gamma lut from AAL */
> 
> I would like to place AAL definition in AAL driver and pass it to gamma
> driver.
> 

This is not only for AAL, actually; I should remove that comment as it
may actually be misleading.

The default LUT size (512) is relevant for both the AAL case and the
older SoCs, where the LUT size is 512 and no multi-register.

I'll remove that comment in the next version

Regards,
Angelo

[PATCH v4 04/11] drm/mediatek: gamma: Improve and simplify HW LUT calculation

[AngeloGioacchino Del Regno]

Use drm_color_lut_extract() to avoid open-coding the bits reduction
calculations for each color channel and use a struct drm_color_lut
to temporarily store the information instead of an array of u32.

Also, slightly improve the precision of the HW LUT calculation in the
LUT DIFF case by performing the subtractions on the 16-bits values and
doing the 10 bits conversion later.

Signed-off-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Reviewed-by: Jason-JH.Lin <jason-jh.lin@mediatek.com>
---
 drivers/gpu/drm/mediatek/mtk_disp_gamma.c | 30 +++++++++++++++--------
 1 file changed, 20 insertions(+), 10 deletions(-)

diff --git a/drivers/gpu/drm/mediatek/mtk_disp_gamma.c b/drivers/gpu/drm/mediatek/mtk_disp_gamma.c
index d194d9bc2e2b..60ccea8c1e1a 100644
--- a/drivers/gpu/drm/mediatek/mtk_disp_gamma.c
+++ b/drivers/gpu/drm/mediatek/mtk_disp_gamma.c
@@ -77,7 +77,6 @@ void mtk_gamma_set_common(struct device *dev, void __iomem *regs, struct drm_crt
 	bool lut_diff;
 	u16 lut_size;
 	u32 word;
-	u32 diff[3] = {0};
 
 	/* If there's no gamma lut there's nothing to do here. */
 	if (!state->gamma_lut)
@@ -97,18 +96,29 @@ void mtk_gamma_set_common(struct device *dev, void __iomem *regs, struct drm_crt
 	lut_base = regs + DISP_GAMMA_LUT;
 	lut = (struct drm_color_lut *)state->gamma_lut->data;
 	for (i = 0; i < lut_size; i++) {
+		struct drm_color_lut diff, hwlut;
+
+		hwlut.red = drm_color_lut_extract(lut[i].red, 10);
+		hwlut.green = drm_color_lut_extract(lut[i].green, 10);
+		hwlut.blue = drm_color_lut_extract(lut[i].blue, 10);
+
 		if (!lut_diff || (i % 2 == 0)) {
-			word = (((lut[i].red >> 6) & LUT_10BIT_MASK) << 20) +
-				(((lut[i].green >> 6) & LUT_10BIT_MASK) << 10) +
-				((lut[i].blue >> 6) & LUT_10BIT_MASK);
+			word = hwlut.red << 20 +
+			       hwlut.green << 10 +
+			       hwlut.red;
 		} else {
-			diff[0] = (lut[i].red >> 6) - (lut[i - 1].red >> 6);
-			diff[1] = (lut[i].green >> 6) - (lut[i - 1].green >> 6);
-			diff[2] = (lut[i].blue >> 6) - (lut[i - 1].blue >> 6);
+			diff.red = lut[i].red - lut[i - 1].red;
+			diff.red = drm_color_lut_extract(diff.red, 10);
+
+			diff.green = lut[i].green - lut[i - 1].green;
+			diff.green = drm_color_lut_extract(diff.green, 10);
+
+			diff.blue = lut[i].blue - lut[i - 1].blue;
+			diff.blue = drm_color_lut_extract(diff.blue, 10);
 
-			word = ((diff[0] & LUT_10BIT_MASK) << 20) +
-				((diff[1] & LUT_10BIT_MASK) << 10) +
-				(diff[2] & LUT_10BIT_MASK);
+			word = diff.blue << 20 +
+			       diff.green << 10 +
+			       diff.red;
 		}
 		writel(word, (lut_base + i * 4));
 	}
-- 
2.40.1

[PATCH v4 05/11] drm/mediatek: gamma: Enable the Gamma LUT table only after programming

[AngeloGioacchino Del Regno]

Move the write to DISP_GAMMA_CFG to enable the Gamma LUT to after
programming the actual table to avoid potential visual glitches during
table modification.

Signed-off-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Reviewed-by: Jason-JH.Lin <jason-jh.lin@mediatek.com>
---
 drivers/gpu/drm/mediatek/mtk_disp_gamma.c | 13 ++++++++-----
 1 file changed, 8 insertions(+), 5 deletions(-)

diff --git a/drivers/gpu/drm/mediatek/mtk_disp_gamma.c b/drivers/gpu/drm/mediatek/mtk_disp_gamma.c
index 60ccea8c1e1a..1592614b6de7 100644
--- a/drivers/gpu/drm/mediatek/mtk_disp_gamma.c
+++ b/drivers/gpu/drm/mediatek/mtk_disp_gamma.c
@@ -71,12 +71,12 @@ unsigned int mtk_gamma_get_lut_size(struct device *dev)
 void mtk_gamma_set_common(struct device *dev, void __iomem *regs, struct drm_crtc_state *state)
 {
 	struct mtk_disp_gamma *gamma = dev_get_drvdata(dev);
-	unsigned int i, reg;
+	unsigned int i;
 	struct drm_color_lut *lut;
 	void __iomem *lut_base;
 	bool lut_diff;
 	u16 lut_size;
-	u32 word;
+	u32 cfg_val, word;
 
 	/* If there's no gamma lut there's nothing to do here. */
 	if (!state->gamma_lut)
@@ -90,9 +90,7 @@ void mtk_gamma_set_common(struct device *dev, void __iomem *regs, struct drm_crt
 		lut_size = LUT_SIZE_DEFAULT;
 	}
 
-	reg = readl(regs + DISP_GAMMA_CFG);
-	reg = reg | GAMMA_LUT_EN;
-	writel(reg, regs + DISP_GAMMA_CFG);
+	cfg_val = readl(regs + DISP_GAMMA_CFG);
 	lut_base = regs + DISP_GAMMA_LUT;
 	lut = (struct drm_color_lut *)state->gamma_lut->data;
 	for (i = 0; i < lut_size; i++) {
@@ -122,6 +120,11 @@ void mtk_gamma_set_common(struct device *dev, void __iomem *regs, struct drm_crt
 		}
 		writel(word, (lut_base + i * 4));
 	}
+
+	/* Enable the gamma table */
+	cfg_val = cfg_val | GAMMA_LUT_EN;
+
+	writel(cfg_val, regs + DISP_GAMMA_CFG);
 }
 
 void mtk_gamma_set(struct device *dev, struct drm_crtc_state *state)
-- 
2.40.1

Re: [PATCH v4 05/11] drm/mediatek: gamma: Enable the Gamma LUT table only after programming

[CK Hu (胡俊光)]

Hi, Angelo:

On Thu, 2023-05-18 at 12:48 +0200, AngeloGioacchino Del Regno wrote:
> External email : Please do not click links or open attachments until
> you have verified the sender or the content.
> 
> 
> Move the write to DISP_GAMMA_CFG to enable the Gamma LUT to after
> programming the actual table to avoid potential visual glitches
> during
> table modification.

I think user could update the lut table frequently, so when do you
disable the gamma function before next update? In addition, if we
really care the glitches, update the register in vblank period which
should use cmdq to update the register. But now, I think we do not care
the glitches. You may skip this patch, or fix the problem I mention.

Regards,
CK

> 
> Signed-off-by: AngeloGioacchino Del Regno <
> angelogioacchino.delregno@collabora.com>
> Reviewed-by: Jason-JH.Lin <jason-jh.lin@mediatek.com>
> ---
>  drivers/gpu/drm/mediatek/mtk_disp_gamma.c | 13 ++++++++-----
>  1 file changed, 8 insertions(+), 5 deletions(-)
> 
> diff --git a/drivers/gpu/drm/mediatek/mtk_disp_gamma.c
> b/drivers/gpu/drm/mediatek/mtk_disp_gamma.c
> index 60ccea8c1e1a..1592614b6de7 100644
> --- a/drivers/gpu/drm/mediatek/mtk_disp_gamma.c
> +++ b/drivers/gpu/drm/mediatek/mtk_disp_gamma.c
> @@ -71,12 +71,12 @@ unsigned int mtk_gamma_get_lut_size(struct device
> *dev)
>  void mtk_gamma_set_common(struct device *dev, void __iomem *regs,
> struct drm_crtc_state *state)
>  {
>         struct mtk_disp_gamma *gamma = dev_get_drvdata(dev);
> -       unsigned int i, reg;
> +       unsigned int i;
>         struct drm_color_lut *lut;
>         void __iomem *lut_base;
>         bool lut_diff;
>         u16 lut_size;
> -       u32 word;
> +       u32 cfg_val, word;
> 
>         /* If there's no gamma lut there's nothing to do here. */
>         if (!state->gamma_lut)
> @@ -90,9 +90,7 @@ void mtk_gamma_set_common(struct device *dev, void
> __iomem *regs, struct drm_crt
>                 lut_size = LUT_SIZE_DEFAULT;
>         }
> 
> -       reg = readl(regs + DISP_GAMMA_CFG);
> -       reg = reg | GAMMA_LUT_EN;
> -       writel(reg, regs + DISP_GAMMA_CFG);
> +       cfg_val = readl(regs + DISP_GAMMA_CFG);
>         lut_base = regs + DISP_GAMMA_LUT;
>         lut = (struct drm_color_lut *)state->gamma_lut->data;
>         for (i = 0; i < lut_size; i++) {
> @@ -122,6 +120,11 @@ void mtk_gamma_set_common(struct device *dev,
> void __iomem *regs, struct drm_crt
>                 }
>                 writel(word, (lut_base + i * 4));
>         }
> +
> +       /* Enable the gamma table */
> +       cfg_val = cfg_val | GAMMA_LUT_EN;
> +
> +       writel(cfg_val, regs + DISP_GAMMA_CFG);
>  }
> 
>  void mtk_gamma_set(struct device *dev, struct drm_crtc_state *state)
> --
> 2.40.1
> 

Re: [PATCH v4 05/11] drm/mediatek: gamma: Enable the Gamma LUT table only after programming

[AngeloGioacchino Del Regno]

Il 22/05/23 12:00, CK Hu (胡俊光) ha scritto:
> Hi, Angelo:
> 
> On Thu, 2023-05-18 at 12:48 +0200, AngeloGioacchino Del Regno wrote:
>> External email : Please do not click links or open attachments until
>> you have verified the sender or the content.
>>
>>
>> Move the write to DISP_GAMMA_CFG to enable the Gamma LUT to after
>> programming the actual table to avoid potential visual glitches
>> during
>> table modification.
> 
> I think user could update the lut table frequently, so when do you
> disable the gamma function before next update? In addition, if we
> really care the glitches, update the register in vblank period which
> should use cmdq to update the register. But now, I think we do not care
> the glitches. You may skip this patch, or fix the problem I mention.
> 

If you disable the GAMMA function (either set RELAY mode or disable the
GAMMA_LUT_EN bit in GAMMA_CFG), there will be glitches during setting via
the GNOME Night Mode color temperature slider.

This commit prevents a glitch in the case in which the GAMMA LUT registers
are not zeroed before setting the expected LUT, for which reason I disagree
about skipping this patch.

Please note that, while I agree about updating the GAMMA LUT through CMDQ
setting and between vblanks, this requires a lot more effort to implement
and it's out of scope for this specific series; depending on my bandwidth,
this may come later and it would in any case require this patch to move
the LUT enablement to after LUT registers setting. Besides, I have already
tried to enable this through CMDQ, but didn't work as expected and since I
had no time to dig further, I deemed this to be essential for at least an
initial functionality implementation for MT8195, and a cleanup of this
driver.
Obviously, the *only* way to fix *all* of the corner cases of the problem
that you mentioned is to use CMDQ and trying to implement this purely with
cpu writes will in any case be prone to at least some glitches.

In any case, while your concern is valid, I'm sure that you agree with me
on the fact that enabling the LUT before actually programming it is something
that should not happen in principle. For this reason, and for the others that
I've just mentioned, I think that this patch is totally valid.

Regards,
Angelo

> Regards,
> CK
> 
>>
>> Signed-off-by: AngeloGioacchino Del Regno <
>> angelogioacchino.delregno@collabora.com>
>> Reviewed-by: Jason-JH.Lin <jason-jh.lin@mediatek.com>
>> ---
>>   drivers/gpu/drm/mediatek/mtk_disp_gamma.c | 13 ++++++++-----
>>   1 file changed, 8 insertions(+), 5 deletions(-)
>>
>> diff --git a/drivers/gpu/drm/mediatek/mtk_disp_gamma.c
>> b/drivers/gpu/drm/mediatek/mtk_disp_gamma.c
>> index 60ccea8c1e1a..1592614b6de7 100644
>> --- a/drivers/gpu/drm/mediatek/mtk_disp_gamma.c
>> +++ b/drivers/gpu/drm/mediatek/mtk_disp_gamma.c
>> @@ -71,12 +71,12 @@ unsigned int mtk_gamma_get_lut_size(struct device
>> *dev)
>>   void mtk_gamma_set_common(struct device *dev, void __iomem *regs,
>> struct drm_crtc_state *state)
>>   {
>>          struct mtk_disp_gamma *gamma = dev_get_drvdata(dev);
>> -       unsigned int i, reg;
>> +       unsigned int i;
>>          struct drm_color_lut *lut;
>>          void __iomem *lut_base;
>>          bool lut_diff;
>>          u16 lut_size;
>> -       u32 word;
>> +       u32 cfg_val, word;
>>
>>          /* If there's no gamma lut there's nothing to do here. */
>>          if (!state->gamma_lut)
>> @@ -90,9 +90,7 @@ void mtk_gamma_set_common(struct device *dev, void
>> __iomem *regs, struct drm_crt
>>                  lut_size = LUT_SIZE_DEFAULT;
>>          }
>>
>> -       reg = readl(regs + DISP_GAMMA_CFG);
>> -       reg = reg | GAMMA_LUT_EN;
>> -       writel(reg, regs + DISP_GAMMA_CFG);
>> +       cfg_val = readl(regs + DISP_GAMMA_CFG);
>>          lut_base = regs + DISP_GAMMA_LUT;
>>          lut = (struct drm_color_lut *)state->gamma_lut->data;
>>          for (i = 0; i < lut_size; i++) {
>> @@ -122,6 +120,11 @@ void mtk_gamma_set_common(struct device *dev,
>> void __iomem *regs, struct drm_crt
>>                  }
>>                  writel(word, (lut_base + i * 4));
>>          }
>> +
>> +       /* Enable the gamma table */
>> +       cfg_val = cfg_val | GAMMA_LUT_EN;
>> +
>> +       writel(cfg_val, regs + DISP_GAMMA_CFG);
>>   }
>>
>>   void mtk_gamma_set(struct device *dev, struct drm_crtc_state *state)
>> --
>> 2.40.1
>>

Re: [PATCH v4 05/11] drm/mediatek: gamma: Enable the Gamma LUT table only after programming

[CK Hu (胡俊光)]

Hi, Angelo:

On Mon, 2023-05-22 at 14:25 +0200, AngeloGioacchino Del Regno wrote:
> External email : Please do not click links or open attachments until
> you have verified the sender or the content.
> 
> 
> Il 22/05/23 12:00, CK Hu (胡俊光) ha scritto:
> > Hi, Angelo:
> > 
> > On Thu, 2023-05-18 at 12:48 +0200, AngeloGioacchino Del Regno
> > wrote:
> > > External email : Please do not click links or open attachments
> > > until
> > > you have verified the sender or the content.
> > > 
> > > 
> > > Move the write to DISP_GAMMA_CFG to enable the Gamma LUT to after
> > > programming the actual table to avoid potential visual glitches
> > > during
> > > table modification.
> > 
> > I think user could update the lut table frequently, so when do you
> > disable the gamma function before next update? In addition, if we
> > really care the glitches, update the register in vblank period
> > which
> > should use cmdq to update the register. But now, I think we do not
> > care
> > the glitches. You may skip this patch, or fix the problem I
> > mention.
> > 
> 
> If you disable the GAMMA function (either set RELAY mode or disable
> the
> GAMMA_LUT_EN bit in GAMMA_CFG), there will be glitches during setting
> via
> the GNOME Night Mode color temperature slider.
> 
> This commit prevents a glitch in the case in which the GAMMA LUT
> registers
> are not zeroed before setting the expected LUT, for which reason I
> disagree
> about skipping this patch.
> 
> Please note that, while I agree about updating the GAMMA LUT through
> CMDQ
> setting and between vblanks, this requires a lot more effort to
> implement
> and it's out of scope for this specific series; depending on my
> bandwidth,
> this may come later and it would in any case require this patch to
> move
> the LUT enablement to after LUT registers setting. Besides, I have
> already
> tried to enable this through CMDQ, but didn't work as expected and
> since I
> had no time to dig further, I deemed this to be essential for at
> least an
> initial functionality implementation for MT8195, and a cleanup of
> this
> driver.
> Obviously, the *only* way to fix *all* of the corner cases of the
> problem
> that you mentioned is to use CMDQ and trying to implement this purely
> with
> cpu writes will in any case be prone to at least some glitches.
> 
> In any case, while your concern is valid, I'm sure that you agree
> with me
> on the fact that enabling the LUT before actually programming it is
> something
> that should not happen in principle. For this reason, and for the
> others that
> I've just mentioned, I think that this patch is totally valid.

OK. So please add these comment to patch description so that we could
know there is something to do.

Regards,
CK

> 
> Regards,
> Angelo
> 
> > Regards,
> > CK
> > 
> > > 
> > > Signed-off-by: AngeloGioacchino Del Regno <
> > > angelogioacchino.delregno@collabora.com>
> > > Reviewed-by: Jason-JH.Lin <jason-jh.lin@mediatek.com>
> > > ---
> > >   drivers/gpu/drm/mediatek/mtk_disp_gamma.c | 13 ++++++++-----
> > >   1 file changed, 8 insertions(+), 5 deletions(-)
> > > 
> > > diff --git a/drivers/gpu/drm/mediatek/mtk_disp_gamma.c
> > > b/drivers/gpu/drm/mediatek/mtk_disp_gamma.c
> > > index 60ccea8c1e1a..1592614b6de7 100644
> > > --- a/drivers/gpu/drm/mediatek/mtk_disp_gamma.c
> > > +++ b/drivers/gpu/drm/mediatek/mtk_disp_gamma.c
> > > @@ -71,12 +71,12 @@ unsigned int mtk_gamma_get_lut_size(struct
> > > device
> > > *dev)
> > >   void mtk_gamma_set_common(struct device *dev, void __iomem
> > > *regs,
> > > struct drm_crtc_state *state)
> > >   {
> > >          struct mtk_disp_gamma *gamma = dev_get_drvdata(dev);
> > > -       unsigned int i, reg;
> > > +       unsigned int i;
> > >          struct drm_color_lut *lut;
> > >          void __iomem *lut_base;
> > >          bool lut_diff;
> > >          u16 lut_size;
> > > -       u32 word;
> > > +       u32 cfg_val, word;
> > > 
> > >          /* If there's no gamma lut there's nothing to do here.
> > > */
> > >          if (!state->gamma_lut)
> > > @@ -90,9 +90,7 @@ void mtk_gamma_set_common(struct device *dev,
> > > void
> > > __iomem *regs, struct drm_crt
> > >                  lut_size = LUT_SIZE_DEFAULT;
> > >          }
> > > 
> > > -       reg = readl(regs + DISP_GAMMA_CFG);
> > > -       reg = reg | GAMMA_LUT_EN;
> > > -       writel(reg, regs + DISP_GAMMA_CFG);
> > > +       cfg_val = readl(regs + DISP_GAMMA_CFG);
> > >          lut_base = regs + DISP_GAMMA_LUT;
> > >          lut = (struct drm_color_lut *)state->gamma_lut->data;
> > >          for (i = 0; i < lut_size; i++) {
> > > @@ -122,6 +120,11 @@ void mtk_gamma_set_common(struct device
> > > *dev,
> > > void __iomem *regs, struct drm_crt
> > >                  }
> > >                  writel(word, (lut_base + i * 4));
> > >          }
> > > +
> > > +       /* Enable the gamma table */
> > > +       cfg_val = cfg_val | GAMMA_LUT_EN;
> > > +
> > > +       writel(cfg_val, regs + DISP_GAMMA_CFG);
> > >   }
> > > 
> > >   void mtk_gamma_set(struct device *dev, struct drm_crtc_state
> > > *state)
> > > --
> > > 2.40.1
> > > 
> 
> 

[PATCH v4 06/11] drm/mediatek: gamma: Use bitfield macros

[AngeloGioacchino Del Regno]

Make the code more robust and improve readability by using bitfield
macros instead of open coding bit operations.
While at it, also add a definition for LUT_BITS_DEFAULT.

Signed-off-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Reviewed-by: Jason-JH.Lin <jason-jh.lin@mediatek.com>
---
 drivers/gpu/drm/mediatek/mtk_disp_gamma.c | 41 ++++++++++++++---------
 1 file changed, 26 insertions(+), 15 deletions(-)

diff --git a/drivers/gpu/drm/mediatek/mtk_disp_gamma.c b/drivers/gpu/drm/mediatek/mtk_disp_gamma.c
index 1592614b6de7..ed2aa1fb0171 100644
--- a/drivers/gpu/drm/mediatek/mtk_disp_gamma.c
+++ b/drivers/gpu/drm/mediatek/mtk_disp_gamma.c
@@ -3,6 +3,7 @@
  * Copyright (c) 2021 MediaTek Inc.
  */
 
+#include <linux/bitfield.h>
 #include <linux/clk.h>
 #include <linux/component.h>
 #include <linux/module.h>
@@ -22,9 +23,16 @@
 #define GAMMA_LUT_EN					BIT(1)
 #define GAMMA_DITHERING					BIT(2)
 #define DISP_GAMMA_SIZE				0x0030
+#define DISP_GAMMA_SIZE_HSIZE				GENMASK(28, 16)
+#define DISP_GAMMA_SIZE_VSIZE				GENMASK(12, 0)
 #define DISP_GAMMA_LUT				0x0700
 
+#define DISP_GAMMA_LUT_10BIT_R			GENMASK(29, 20)
+#define DISP_GAMMA_LUT_10BIT_G			GENMASK(19, 10)
+#define DISP_GAMMA_LUT_10BIT_B			GENMASK(9, 0)
+
 #define LUT_10BIT_MASK				0x03ff
+#define LUT_BITS_DEFAULT			10
 #define LUT_SIZE_DEFAULT			512 /* for setting gamma lut from AAL */
 
 struct mtk_disp_gamma_data {
@@ -96,33 +104,33 @@ void mtk_gamma_set_common(struct device *dev, void __iomem *regs, struct drm_crt
 	for (i = 0; i < lut_size; i++) {
 		struct drm_color_lut diff, hwlut;
 
-		hwlut.red = drm_color_lut_extract(lut[i].red, 10);
-		hwlut.green = drm_color_lut_extract(lut[i].green, 10);
-		hwlut.blue = drm_color_lut_extract(lut[i].blue, 10);
+		hwlut.red = drm_color_lut_extract(lut[i].red, LUT_BITS_DEFAULT);
+		hwlut.green = drm_color_lut_extract(lut[i].green, LUT_BITS_DEFAULT);
+		hwlut.blue = drm_color_lut_extract(lut[i].blue, LUT_BITS_DEFAULT);
 
 		if (!lut_diff || (i % 2 == 0)) {
-			word = hwlut.red << 20 +
-			       hwlut.green << 10 +
-			       hwlut.red;
+			word = FIELD_PREP(DISP_GAMMA_LUT_10BIT_R, hwlut.red);
+			word |= FIELD_PREP(DISP_GAMMA_LUT_10BIT_G, hwlut.green);
+			word |= FIELD_PREP(DISP_GAMMA_LUT_10BIT_B, hwlut.blue);
 		} else {
 			diff.red = lut[i].red - lut[i - 1].red;
-			diff.red = drm_color_lut_extract(diff.red, 10);
+			diff.red = drm_color_lut_extract(diff.red, LUT_BITS_DEFAULT);
 
 			diff.green = lut[i].green - lut[i - 1].green;
-			diff.green = drm_color_lut_extract(diff.green, 10);
+			diff.green = drm_color_lut_extract(diff.green, LUT_BITS_DEFAULT);
 
 			diff.blue = lut[i].blue - lut[i - 1].blue;
-			diff.blue = drm_color_lut_extract(diff.blue, 10);
+			diff.blue = drm_color_lut_extract(diff.blue, LUT_BITS_DEFAULT);
 
-			word = diff.blue << 20 +
-			       diff.green << 10 +
-			       diff.red;
+			word = FIELD_PREP(DISP_GAMMA_LUT_10BIT_R, diff.red);
+			word |= FIELD_PREP(DISP_GAMMA_LUT_10BIT_G, diff.green);
+			word |= FIELD_PREP(DISP_GAMMA_LUT_10BIT_B, diff.blue);
 		}
 		writel(word, (lut_base + i * 4));
 	}
 
 	/* Enable the gamma table */
-	cfg_val = cfg_val | GAMMA_LUT_EN;
+	cfg_val |= FIELD_PREP(GAMMA_LUT_EN, 1);
 
 	writel(cfg_val, regs + DISP_GAMMA_CFG);
 }
@@ -139,9 +147,12 @@ void mtk_gamma_config(struct device *dev, unsigned int w,
 		      unsigned int bpc, struct cmdq_pkt *cmdq_pkt)
 {
 	struct mtk_disp_gamma *gamma = dev_get_drvdata(dev);
+	u32 sz;
+
+	sz = FIELD_PREP(DISP_GAMMA_SIZE_HSIZE, w);
+	sz |= FIELD_PREP(DISP_GAMMA_SIZE_VSIZE, h);
 
-	mtk_ddp_write(cmdq_pkt, h << 16 | w, &gamma->cmdq_reg, gamma->regs,
-		      DISP_GAMMA_SIZE);
+	mtk_ddp_write(cmdq_pkt, sz, &gamma->cmdq_reg, gamma->regs, DISP_GAMMA_SIZE);
 	if (gamma->data && gamma->data->has_dither)
 		mtk_dither_set_common(gamma->regs, &gamma->cmdq_reg, bpc,
 				      DISP_GAMMA_CFG, GAMMA_DITHERING, cmdq_pkt);
-- 
2.40.1

Re: [PATCH v4 06/11] drm/mediatek: gamma: Use bitfield macros

[CK Hu (胡俊光)]

Hi, Angelo:

On Thu, 2023-05-18 at 12:48 +0200, AngeloGioacchino Del Regno wrote:
> External email : Please do not click links or open attachments until
> you have verified the sender or the content.
> 
> 
> Make the code more robust and improve readability by using bitfield
> macros instead of open coding bit operations.
> While at it, also add a definition for LUT_BITS_DEFAULT.
> 
> Signed-off-by: AngeloGioacchino Del Regno <
> angelogioacchino.delregno@collabora.com>
> Reviewed-by: Jason-JH.Lin <jason-jh.lin@mediatek.com>
> ---
>  drivers/gpu/drm/mediatek/mtk_disp_gamma.c | 41 ++++++++++++++-------
> --
>  1 file changed, 26 insertions(+), 15 deletions(-)
> 
> diff --git a/drivers/gpu/drm/mediatek/mtk_disp_gamma.c
> b/drivers/gpu/drm/mediatek/mtk_disp_gamma.c
> index 1592614b6de7..ed2aa1fb0171 100644
> --- a/drivers/gpu/drm/mediatek/mtk_disp_gamma.c
> +++ b/drivers/gpu/drm/mediatek/mtk_disp_gamma.c
> @@ -3,6 +3,7 @@
>   * Copyright (c) 2021 MediaTek Inc.
>   */
> 
> +#include <linux/bitfield.h>
>  #include <linux/clk.h>
>  #include <linux/component.h>
>  #include <linux/module.h>
> @@ -22,9 +23,16 @@
>  #define GAMMA_LUT_EN                                   BIT(1)
>  #define
> GAMMA_DITHERING                                        BIT(2)
>  #define DISP_GAMMA_SIZE                                0x0030
> +#define DISP_GAMMA_SIZE_HSIZE                          GENMASK(28,
> 16)
> +#define DISP_GAMMA_SIZE_VSIZE                          GENMASK(12,
> 0)
>  #define DISP_GAMMA_LUT                         0x0700
> 
> +#define DISP_GAMMA_LUT_10BIT_R                 GENMASK(29, 20)
> +#define DISP_GAMMA_LUT_10BIT_G                 GENMASK(19, 10)
> +#define DISP_GAMMA_LUT_10BIT_B                 GENMASK(9, 0)
> +
>  #define LUT_10BIT_MASK                         0x03ff
> +#define LUT_BITS_DEFAULT                       10

This is used only for AAL after patch "drm/mediatek: gamma: Support
specifying number of bits per LUT component", so I would like move AAL
definition to AAL driver and pass it to gamma driver.

Regards,
CK

>  #define LUT_SIZE_DEFAULT                       512 /* for setting
> gamma lut from AAL */
> 
>  struct mtk_disp_gamma_data {
> @@ -96,33 +104,33 @@ void mtk_gamma_set_common(struct device *dev,
> void __iomem *regs, struct drm_crt
>         for (i = 0; i < lut_size; i++) {
>                 struct drm_color_lut diff, hwlut;
> 
> -               hwlut.red = drm_color_lut_extract(lut[i].red, 10);
> -               hwlut.green = drm_color_lut_extract(lut[i].green,
> 10);
> -               hwlut.blue = drm_color_lut_extract(lut[i].blue, 10);
> +               hwlut.red = drm_color_lut_extract(lut[i].red,
> LUT_BITS_DEFAULT);
> +               hwlut.green = drm_color_lut_extract(lut[i].green,
> LUT_BITS_DEFAULT);
> +               hwlut.blue = drm_color_lut_extract(lut[i].blue,
> LUT_BITS_DEFAULT);
> 
>                 if (!lut_diff || (i % 2 == 0)) {
> -                       word = hwlut.red << 20 +
> -                              hwlut.green << 10 +
> -                              hwlut.red;
> +                       word = FIELD_PREP(DISP_GAMMA_LUT_10BIT_R,
> hwlut.red);
> +                       word |= FIELD_PREP(DISP_GAMMA_LUT_10BIT_G,
> hwlut.green);
> +                       word |= FIELD_PREP(DISP_GAMMA_LUT_10BIT_B,
> hwlut.blue);
>                 } else {
>                         diff.red = lut[i].red - lut[i - 1].red;
> -                       diff.red = drm_color_lut_extract(diff.red,
> 10);
> +                       diff.red = drm_color_lut_extract(diff.red,
> LUT_BITS_DEFAULT);
> 
>                         diff.green = lut[i].green - lut[i - 1].green;
> -                       diff.green =
> drm_color_lut_extract(diff.green, 10);
> +                       diff.green =
> drm_color_lut_extract(diff.green, LUT_BITS_DEFAULT);
> 
>                         diff.blue = lut[i].blue - lut[i - 1].blue;
> -                       diff.blue = drm_color_lut_extract(diff.blue,
> 10);
> +                       diff.blue = drm_color_lut_extract(diff.blue,
> LUT_BITS_DEFAULT);
> 
> -                       word = diff.blue << 20 +
> -                              diff.green << 10 +
> -                              diff.red;
> +                       word = FIELD_PREP(DISP_GAMMA_LUT_10BIT_R,
> diff.red);
> +                       word |= FIELD_PREP(DISP_GAMMA_LUT_10BIT_G,
> diff.green);
> +                       word |= FIELD_PREP(DISP_GAMMA_LUT_10BIT_B,
> diff.blue);
>                 }
>                 writel(word, (lut_base + i * 4));
>         }
> 
>         /* Enable the gamma table */
> -       cfg_val = cfg_val | GAMMA_LUT_EN;
> +       cfg_val |= FIELD_PREP(GAMMA_LUT_EN, 1);
> 
>         writel(cfg_val, regs + DISP_GAMMA_CFG);
>  }
> @@ -139,9 +147,12 @@ void mtk_gamma_config(struct device *dev,
> unsigned int w,
>                       unsigned int bpc, struct cmdq_pkt *cmdq_pkt)
>  {
>         struct mtk_disp_gamma *gamma = dev_get_drvdata(dev);
> +       u32 sz;
> +
> +       sz = FIELD_PREP(DISP_GAMMA_SIZE_HSIZE, w);
> +       sz |= FIELD_PREP(DISP_GAMMA_SIZE_VSIZE, h);
> 
> -       mtk_ddp_write(cmdq_pkt, h << 16 | w, &gamma->cmdq_reg, gamma-
> >regs,
> -                     DISP_GAMMA_SIZE);
> +       mtk_ddp_write(cmdq_pkt, sz, &gamma->cmdq_reg, gamma->regs,
> DISP_GAMMA_SIZE);
>         if (gamma->data && gamma->data->has_dither)
>                 mtk_dither_set_common(gamma->regs, &gamma->cmdq_reg,
> bpc,
>                                       DISP_GAMMA_CFG,
> GAMMA_DITHERING, cmdq_pkt);
> --
> 2.40.1
> 

Re: [PATCH v4 06/11] drm/mediatek: gamma: Use bitfield macros

[AngeloGioacchino Del Regno]

Il 26/05/23 07:32, CK Hu (胡俊光) ha scritto:
> Hi, Angelo:
> 
> On Thu, 2023-05-18 at 12:48 +0200, AngeloGioacchino Del Regno wrote:
>> External email : Please do not click links or open attachments until
>> you have verified the sender or the content.
>>
>>
>> Make the code more robust and improve readability by using bitfield
>> macros instead of open coding bit operations.
>> While at it, also add a definition for LUT_BITS_DEFAULT.
>>
>> Signed-off-by: AngeloGioacchino Del Regno <
>> angelogioacchino.delregno@collabora.com>
>> Reviewed-by: Jason-JH.Lin <jason-jh.lin@mediatek.com>
>> ---
>>   drivers/gpu/drm/mediatek/mtk_disp_gamma.c | 41 ++++++++++++++-------
>> --
>>   1 file changed, 26 insertions(+), 15 deletions(-)
>>
>> diff --git a/drivers/gpu/drm/mediatek/mtk_disp_gamma.c
>> b/drivers/gpu/drm/mediatek/mtk_disp_gamma.c
>> index 1592614b6de7..ed2aa1fb0171 100644
>> --- a/drivers/gpu/drm/mediatek/mtk_disp_gamma.c
>> +++ b/drivers/gpu/drm/mediatek/mtk_disp_gamma.c
>> @@ -3,6 +3,7 @@
>>    * Copyright (c) 2021 MediaTek Inc.
>>    */
>>
>> +#include <linux/bitfield.h>
>>   #include <linux/clk.h>
>>   #include <linux/component.h>
>>   #include <linux/module.h>
>> @@ -22,9 +23,16 @@
>>   #define GAMMA_LUT_EN                                   BIT(1)
>>   #define
>> GAMMA_DITHERING                                        BIT(2)
>>   #define DISP_GAMMA_SIZE                                0x0030
>> +#define DISP_GAMMA_SIZE_HSIZE                          GENMASK(28,
>> 16)
>> +#define DISP_GAMMA_SIZE_VSIZE                          GENMASK(12,
>> 0)
>>   #define DISP_GAMMA_LUT                         0x0700
>>
>> +#define DISP_GAMMA_LUT_10BIT_R                 GENMASK(29, 20)
>> +#define DISP_GAMMA_LUT_10BIT_G                 GENMASK(19, 10)
>> +#define DISP_GAMMA_LUT_10BIT_B                 GENMASK(9, 0)
>> +
>>   #define LUT_10BIT_MASK                         0x03ff
>> +#define LUT_BITS_DEFAULT                       10
> 
> This is used only for AAL after patch "drm/mediatek: gamma: Support
> specifying number of bits per LUT component", so I would like move AAL
> definition to AAL driver and pass it to gamma driver.
> 

Like LUT_SIZE_DEFAULT, this definition is not only for AAL but also for
the older gamma lut register layout.

In any case, I'll check if there's any clean way to pass AAL's gamma
size to this driver... it's a different "component", so this may get
complicated.

Let's see what I can come up with in v5...

Thanks,
Angelo

[PATCH v4 07/11] drm/mediatek: gamma: Support specifying number of bits per LUT component

[AngeloGioacchino Del Regno]

New SoCs, like MT8195, not only may support bigger lookup tables, but
have got a different register layout to support bigger precision:
support specifying the number of `lut_bits` for each SoC and use it
in mtk_gamma_set_common() to perform the right calculation.

Signed-off-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Reviewed-by: Jason-JH.Lin <jason-jh.lin@mediatek.com>
---
 drivers/gpu/drm/mediatek/mtk_disp_gamma.c | 18 ++++++++++++------
 1 file changed, 12 insertions(+), 6 deletions(-)

diff --git a/drivers/gpu/drm/mediatek/mtk_disp_gamma.c b/drivers/gpu/drm/mediatek/mtk_disp_gamma.c
index ed2aa1fb0171..62e1e50d2671 100644
--- a/drivers/gpu/drm/mediatek/mtk_disp_gamma.c
+++ b/drivers/gpu/drm/mediatek/mtk_disp_gamma.c
@@ -39,6 +39,7 @@ struct mtk_disp_gamma_data {
 	bool has_dither;
 	bool lut_diff;
 	u16 lut_size;
+	u8 lut_bits;
 };
 
 /*
@@ -84,6 +85,7 @@ void mtk_gamma_set_common(struct device *dev, void __iomem *regs, struct drm_crt
 	void __iomem *lut_base;
 	bool lut_diff;
 	u16 lut_size;
+	u8 lut_bits;
 	u32 cfg_val, word;
 
 	/* If there's no gamma lut there's nothing to do here. */
@@ -92,9 +94,11 @@ void mtk_gamma_set_common(struct device *dev, void __iomem *regs, struct drm_crt
 
 	if (gamma && gamma->data) {
 		lut_diff = gamma->data->lut_diff;
+		lut_bits = gamma->data->lut_bits;
 		lut_size = gamma->data->lut_size;
 	} else {
 		lut_diff = false;
+		lut_bits = LUT_BITS_DEFAULT;
 		lut_size = LUT_SIZE_DEFAULT;
 	}
 
@@ -104,9 +108,9 @@ void mtk_gamma_set_common(struct device *dev, void __iomem *regs, struct drm_crt
 	for (i = 0; i < lut_size; i++) {
 		struct drm_color_lut diff, hwlut;
 
-		hwlut.red = drm_color_lut_extract(lut[i].red, LUT_BITS_DEFAULT);
-		hwlut.green = drm_color_lut_extract(lut[i].green, LUT_BITS_DEFAULT);
-		hwlut.blue = drm_color_lut_extract(lut[i].blue, LUT_BITS_DEFAULT);
+		hwlut.red = drm_color_lut_extract(lut[i].red, lut_bits);
+		hwlut.green = drm_color_lut_extract(lut[i].green, lut_bits);
+		hwlut.blue = drm_color_lut_extract(lut[i].blue, lut_bits);
 
 		if (!lut_diff || (i % 2 == 0)) {
 			word = FIELD_PREP(DISP_GAMMA_LUT_10BIT_R, hwlut.red);
@@ -114,13 +118,13 @@ void mtk_gamma_set_common(struct device *dev, void __iomem *regs, struct drm_crt
 			word |= FIELD_PREP(DISP_GAMMA_LUT_10BIT_B, hwlut.blue);
 		} else {
 			diff.red = lut[i].red - lut[i - 1].red;
-			diff.red = drm_color_lut_extract(diff.red, LUT_BITS_DEFAULT);
+			diff.red = drm_color_lut_extract(diff.red, lut_bits);
 
 			diff.green = lut[i].green - lut[i - 1].green;
-			diff.green = drm_color_lut_extract(diff.green, LUT_BITS_DEFAULT);
+			diff.green = drm_color_lut_extract(diff.green, lut_bits);
 
 			diff.blue = lut[i].blue - lut[i - 1].blue;
-			diff.blue = drm_color_lut_extract(diff.blue, LUT_BITS_DEFAULT);
+			diff.blue = drm_color_lut_extract(diff.blue, lut_bits);
 
 			word = FIELD_PREP(DISP_GAMMA_LUT_10BIT_R, diff.red);
 			word |= FIELD_PREP(DISP_GAMMA_LUT_10BIT_G, diff.green);
@@ -237,10 +241,12 @@ static int mtk_disp_gamma_remove(struct platform_device *pdev)
 
 static const struct mtk_disp_gamma_data mt8173_gamma_driver_data = {
 	.has_dither = true,
+	.lut_bits = 10,
 	.lut_size = 512,
 };
 
 static const struct mtk_disp_gamma_data mt8183_gamma_driver_data = {
+	.lut_bits = 10,
 	.lut_diff = true,
 	.lut_size = 512,
 };
-- 
2.40.1

[PATCH v4 08/11] drm/mediatek: gamma: Support multi-bank gamma LUT

[AngeloGioacchino Del Regno]

Newer Gamma IP have got multiple LUT banks: support specifying the
size of the LUT banks and handle bank-switching before programming
the LUT in mtk_gamma_set_common() in preparation for adding support
for MT8195 and newer SoCs.

Suggested-by: Jason-JH.Lin <jason-jh.lin@mediatek.com>
[Angelo: Refactored original commit]
Signed-off-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
---
 drivers/gpu/drm/mediatek/mtk_disp_gamma.c | 78 +++++++++++++++--------
 1 file changed, 51 insertions(+), 27 deletions(-)

diff --git a/drivers/gpu/drm/mediatek/mtk_disp_gamma.c b/drivers/gpu/drm/mediatek/mtk_disp_gamma.c
index 62e1e50d2671..a05c445367ee 100644
--- a/drivers/gpu/drm/mediatek/mtk_disp_gamma.c
+++ b/drivers/gpu/drm/mediatek/mtk_disp_gamma.c
@@ -25,6 +25,8 @@
 #define DISP_GAMMA_SIZE				0x0030
 #define DISP_GAMMA_SIZE_HSIZE				GENMASK(28, 16)
 #define DISP_GAMMA_SIZE_VSIZE				GENMASK(12, 0)
+#define DISP_GAMMA_BANK				0x0100
+#define DISP_GAMMA_BANK_BANK				GENMASK(1, 0)
 #define DISP_GAMMA_LUT				0x0700
 
 #define DISP_GAMMA_LUT_10BIT_R			GENMASK(29, 20)
@@ -38,6 +40,7 @@
 struct mtk_disp_gamma_data {
 	bool has_dither;
 	bool lut_diff;
+	u16 lut_bank_size;
 	u16 lut_size;
 	u8 lut_bits;
 };
@@ -84,9 +87,10 @@ void mtk_gamma_set_common(struct device *dev, void __iomem *regs, struct drm_crt
 	struct drm_color_lut *lut;
 	void __iomem *lut_base;
 	bool lut_diff;
-	u16 lut_size;
+	u16 lut_bank_size, lut_size;
 	u8 lut_bits;
-	u32 cfg_val, word;
+	u32 cfg_val, lbank_val, word;
+	int cur_bank, num_lut_banks;
 
 	/* If there's no gamma lut there's nothing to do here. */
 	if (!state->gamma_lut)
@@ -94,43 +98,61 @@ void mtk_gamma_set_common(struct device *dev, void __iomem *regs, struct drm_crt
 
 	if (gamma && gamma->data) {
 		lut_diff = gamma->data->lut_diff;
+		lut_bank_size = gamma->data->lut_bank_size;
 		lut_bits = gamma->data->lut_bits;
 		lut_size = gamma->data->lut_size;
 	} else {
 		lut_diff = false;
+		lut_bank_size = LUT_SIZE_DEFAULT;
 		lut_bits = LUT_BITS_DEFAULT;
 		lut_size = LUT_SIZE_DEFAULT;
 	}
 
+	if (lut_bank_size)
+		num_lut_banks = lut_size / lut_bank_size;
+	else
+		num_lut_banks = 1;
+
 	cfg_val = readl(regs + DISP_GAMMA_CFG);
 	lut_base = regs + DISP_GAMMA_LUT;
 	lut = (struct drm_color_lut *)state->gamma_lut->data;
-	for (i = 0; i < lut_size; i++) {
-		struct drm_color_lut diff, hwlut;
-
-		hwlut.red = drm_color_lut_extract(lut[i].red, lut_bits);
-		hwlut.green = drm_color_lut_extract(lut[i].green, lut_bits);
-		hwlut.blue = drm_color_lut_extract(lut[i].blue, lut_bits);
-
-		if (!lut_diff || (i % 2 == 0)) {
-			word = FIELD_PREP(DISP_GAMMA_LUT_10BIT_R, hwlut.red);
-			word |= FIELD_PREP(DISP_GAMMA_LUT_10BIT_G, hwlut.green);
-			word |= FIELD_PREP(DISP_GAMMA_LUT_10BIT_B, hwlut.blue);
-		} else {
-			diff.red = lut[i].red - lut[i - 1].red;
-			diff.red = drm_color_lut_extract(diff.red, lut_bits);
-
-			diff.green = lut[i].green - lut[i - 1].green;
-			diff.green = drm_color_lut_extract(diff.green, lut_bits);
-
-			diff.blue = lut[i].blue - lut[i - 1].blue;
-			diff.blue = drm_color_lut_extract(diff.blue, lut_bits);
-
-			word = FIELD_PREP(DISP_GAMMA_LUT_10BIT_R, diff.red);
-			word |= FIELD_PREP(DISP_GAMMA_LUT_10BIT_G, diff.green);
-			word |= FIELD_PREP(DISP_GAMMA_LUT_10BIT_B, diff.blue);
+
+	for (cur_bank = 0; cur_bank < num_lut_banks; cur_bank++) {
+
+		/* Switch gamma bank and set data mode before writing LUT */
+		if (num_lut_banks > 1) {
+			lbank_val = FIELD_PREP(DISP_GAMMA_BANK_BANK, cur_bank);
+			writel(lbank_val, regs + DISP_GAMMA_BANK);
+		}
+
+		for (i = 0; i < lut_bank_size; i++) {
+			int n = (cur_bank * lut_bank_size) + i;
+			struct drm_color_lut diff, hwlut;
+
+			hwlut.red = drm_color_lut_extract(lut[n].red, lut_bits);
+			hwlut.green = drm_color_lut_extract(lut[n].green, lut_bits);
+			hwlut.blue = drm_color_lut_extract(lut[n].blue, lut_bits);
+
+			if (!lut_diff || (i % 2 == 0)) {
+				word = FIELD_PREP(DISP_GAMMA_LUT_10BIT_R, hwlut.red);
+				word |= FIELD_PREP(DISP_GAMMA_LUT_10BIT_G, hwlut.green);
+				word |= FIELD_PREP(DISP_GAMMA_LUT_10BIT_B, hwlut.blue);
+			} else {
+				diff.red = lut[n].red - lut[n - 1].red;
+				diff.red = drm_color_lut_extract(diff.red, lut_bits);
+
+				diff.green = lut[n].green - lut[n - 1].green;
+				diff.green = drm_color_lut_extract(diff.green, lut_bits);
+
+				diff.blue = lut[n].blue - lut[n - 1].blue;
+				diff.blue = drm_color_lut_extract(diff.blue, lut_bits);
+
+				word = FIELD_PREP(DISP_GAMMA_LUT_10BIT_R, diff.red);
+				word |= FIELD_PREP(DISP_GAMMA_LUT_10BIT_G, diff.green);
+				word |= FIELD_PREP(DISP_GAMMA_LUT_10BIT_B, diff.blue);
+			}
+			writel(word, (lut_base + i * 4));
 		}
-		writel(word, (lut_base + i * 4));
 	}
 
 	/* Enable the gamma table */
@@ -241,11 +263,13 @@ static int mtk_disp_gamma_remove(struct platform_device *pdev)
 
 static const struct mtk_disp_gamma_data mt8173_gamma_driver_data = {
 	.has_dither = true,
+	.lut_bank_size = 512,
 	.lut_bits = 10,
 	.lut_size = 512,
 };
 
 static const struct mtk_disp_gamma_data mt8183_gamma_driver_data = {
+	.lut_bank_size = 512,
 	.lut_bits = 10,
 	.lut_diff = true,
 	.lut_size = 512,
-- 
2.40.1

[PATCH v4 09/11] drm/mediatek: gamma: Add support for 12-bit LUT and MT8195

[AngeloGioacchino Del Regno]

Add support for 12-bit gamma lookup tables and introduce the first
user for it: MT8195.
While at it, also reorder the variables in mtk_gamma_set_common()
and rename `lut_base` to `lut0_base` to improve readability.

Signed-off-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Reviewed-by: Jason-JH.Lin <jason-jh.lin@mediatek.com>
---
 drivers/gpu/drm/mediatek/mtk_disp_gamma.c | 61 ++++++++++++++++++-----
 1 file changed, 48 insertions(+), 13 deletions(-)

diff --git a/drivers/gpu/drm/mediatek/mtk_disp_gamma.c b/drivers/gpu/drm/mediatek/mtk_disp_gamma.c
index a05c445367ee..9ae08a2d7da2 100644
--- a/drivers/gpu/drm/mediatek/mtk_disp_gamma.c
+++ b/drivers/gpu/drm/mediatek/mtk_disp_gamma.c
@@ -27,12 +27,20 @@
 #define DISP_GAMMA_SIZE_VSIZE				GENMASK(12, 0)
 #define DISP_GAMMA_BANK				0x0100
 #define DISP_GAMMA_BANK_BANK				GENMASK(1, 0)
+#define DISP_GAMMA_BANK_DATA_MODE			BIT(2)
 #define DISP_GAMMA_LUT				0x0700
+#define DISP_GAMMA_LUT1				0x0b00
 
+/* For 10 bit LUT layout, R/G/B are in the same register */
 #define DISP_GAMMA_LUT_10BIT_R			GENMASK(29, 20)
 #define DISP_GAMMA_LUT_10BIT_G			GENMASK(19, 10)
 #define DISP_GAMMA_LUT_10BIT_B			GENMASK(9, 0)
 
+/* For 12 bit LUT layout, R/G are in LUT, B is in LUT1 */
+#define DISP_GAMMA_LUT_12BIT_R			GENMASK(11, 0)
+#define DISP_GAMMA_LUT_12BIT_G			GENMASK(23, 12)
+#define DISP_GAMMA_LUT_12BIT_B			GENMASK(11, 0)
+
 #define LUT_10BIT_MASK				0x03ff
 #define LUT_BITS_DEFAULT			10
 #define LUT_SIZE_DEFAULT			512 /* for setting gamma lut from AAL */
@@ -83,14 +91,15 @@ unsigned int mtk_gamma_get_lut_size(struct device *dev)
 void mtk_gamma_set_common(struct device *dev, void __iomem *regs, struct drm_crtc_state *state)
 {
 	struct mtk_disp_gamma *gamma = dev_get_drvdata(dev);
-	unsigned int i;
+	void __iomem *lut0_base = regs + DISP_GAMMA_LUT;
+	void __iomem *lut1_base = regs + DISP_GAMMA_LUT1;
+	u32 cfg_val, data_mode, lbank_val, word[2];
+	int cur_bank, num_lut_banks;
+	u16 lut_bank_size, lut_size;
 	struct drm_color_lut *lut;
-	void __iomem *lut_base;
+	unsigned int i;
 	bool lut_diff;
-	u16 lut_bank_size, lut_size;
 	u8 lut_bits;
-	u32 cfg_val, lbank_val, word;
-	int cur_bank, num_lut_banks;
 
 	/* If there's no gamma lut there's nothing to do here. */
 	if (!state->gamma_lut)
@@ -114,14 +123,17 @@ void mtk_gamma_set_common(struct device *dev, void __iomem *regs, struct drm_crt
 		num_lut_banks = 1;
 
 	cfg_val = readl(regs + DISP_GAMMA_CFG);
-	lut_base = regs + DISP_GAMMA_LUT;
 	lut = (struct drm_color_lut *)state->gamma_lut->data;
 
+	/* Switch to 12 bits data mode if supported */
+	data_mode = FIELD_PREP(DISP_GAMMA_BANK_DATA_MODE, !!(lut_bits == 12));
+
 	for (cur_bank = 0; cur_bank < num_lut_banks; cur_bank++) {
 
 		/* Switch gamma bank and set data mode before writing LUT */
 		if (num_lut_banks > 1) {
 			lbank_val = FIELD_PREP(DISP_GAMMA_BANK_BANK, cur_bank);
+			lbank_val |= data_mode;
 			writel(lbank_val, regs + DISP_GAMMA_BANK);
 		}
 
@@ -134,9 +146,15 @@ void mtk_gamma_set_common(struct device *dev, void __iomem *regs, struct drm_crt
 			hwlut.blue = drm_color_lut_extract(lut[n].blue, lut_bits);
 
 			if (!lut_diff || (i % 2 == 0)) {
-				word = FIELD_PREP(DISP_GAMMA_LUT_10BIT_R, hwlut.red);
-				word |= FIELD_PREP(DISP_GAMMA_LUT_10BIT_G, hwlut.green);
-				word |= FIELD_PREP(DISP_GAMMA_LUT_10BIT_B, hwlut.blue);
+				if (lut_bits == 12) {
+					word[0] = FIELD_PREP(DISP_GAMMA_LUT_12BIT_R, hwlut.red);
+					word[0] |= FIELD_PREP(DISP_GAMMA_LUT_12BIT_G, hwlut.green);
+					word[1] = FIELD_PREP(DISP_GAMMA_LUT_12BIT_B, hwlut.blue);
+				} else {
+					word[0] = FIELD_PREP(DISP_GAMMA_LUT_10BIT_R, hwlut.red);
+					word[0] |= FIELD_PREP(DISP_GAMMA_LUT_10BIT_G, hwlut.green);
+					word[0] |= FIELD_PREP(DISP_GAMMA_LUT_10BIT_B, hwlut.blue);
+				}
 			} else {
 				diff.red = lut[n].red - lut[n - 1].red;
 				diff.red = drm_color_lut_extract(diff.red, lut_bits);
@@ -147,11 +165,19 @@ void mtk_gamma_set_common(struct device *dev, void __iomem *regs, struct drm_crt
 				diff.blue = lut[n].blue - lut[n - 1].blue;
 				diff.blue = drm_color_lut_extract(diff.blue, lut_bits);
 
-				word = FIELD_PREP(DISP_GAMMA_LUT_10BIT_R, diff.red);
-				word |= FIELD_PREP(DISP_GAMMA_LUT_10BIT_G, diff.green);
-				word |= FIELD_PREP(DISP_GAMMA_LUT_10BIT_B, diff.blue);
+				if (lut_bits == 12) {
+					word[0] = FIELD_PREP(DISP_GAMMA_LUT_12BIT_R, diff.red);
+					word[0] |= FIELD_PREP(DISP_GAMMA_LUT_12BIT_G, diff.green);
+					word[1] = FIELD_PREP(DISP_GAMMA_LUT_12BIT_B, diff.blue);
+				} else {
+					word[0] = FIELD_PREP(DISP_GAMMA_LUT_10BIT_R, diff.red);
+					word[0] |= FIELD_PREP(DISP_GAMMA_LUT_10BIT_G, diff.green);
+					word[0] |= FIELD_PREP(DISP_GAMMA_LUT_10BIT_B, diff.blue);
+				}
 			}
-			writel(word, (lut_base + i * 4));
+			writel(word[0], (lut0_base + i * 4));
+			if (lut_bits == 12)
+				writel(word[1], (lut1_base + i * 4));
 		}
 	}
 
@@ -275,11 +301,20 @@ static const struct mtk_disp_gamma_data mt8183_gamma_driver_data = {
 	.lut_size = 512,
 };
 
+static const struct mtk_disp_gamma_data mt8195_gamma_driver_data = {
+	.lut_bank_size = 256,
+	.lut_bits = 12,
+	.lut_diff = true,
+	.lut_size = 1024,
+};
+
 static const struct of_device_id mtk_disp_gamma_driver_dt_match[] = {
 	{ .compatible = "mediatek,mt8173-disp-gamma",
 	  .data = &mt8173_gamma_driver_data},
 	{ .compatible = "mediatek,mt8183-disp-gamma",
 	  .data = &mt8183_gamma_driver_data},
+	{ .compatible = "mediatek,mt8195-disp-gamma",
+	  .data = &mt8195_gamma_driver_data},
 	{},
 };
 MODULE_DEVICE_TABLE(of, mtk_disp_gamma_driver_dt_match);
-- 
2.40.1

[PATCH v4 10/11] drm/mediatek: gamma: Make sure relay mode is disabled

[AngeloGioacchino Del Regno]

Disable relay mode at the end of LUT programming to make sure that the
processed image goes through.

Signed-off-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Reviewed-by: Jason-JH.Lin <jason-jh.lin@mediatek.com>
---
 drivers/gpu/drm/mediatek/mtk_disp_gamma.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/drivers/gpu/drm/mediatek/mtk_disp_gamma.c b/drivers/gpu/drm/mediatek/mtk_disp_gamma.c
index 9ae08a2d7da2..ba8a0f93f184 100644
--- a/drivers/gpu/drm/mediatek/mtk_disp_gamma.c
+++ b/drivers/gpu/drm/mediatek/mtk_disp_gamma.c
@@ -20,6 +20,7 @@
 #define DISP_GAMMA_EN				0x0000
 #define GAMMA_EN					BIT(0)
 #define DISP_GAMMA_CFG				0x0020
+#define GAMMA_RELAY_MODE				BIT(0)
 #define GAMMA_LUT_EN					BIT(1)
 #define GAMMA_DITHERING					BIT(2)
 #define DISP_GAMMA_SIZE				0x0030
@@ -184,6 +185,9 @@ void mtk_gamma_set_common(struct device *dev, void __iomem *regs, struct drm_crt
 	/* Enable the gamma table */
 	cfg_val |= FIELD_PREP(GAMMA_LUT_EN, 1);
 
+	/* Disable RELAY mode to pass the processed image */
+	cfg_val &= ~GAMMA_RELAY_MODE;
+
 	writel(cfg_val, regs + DISP_GAMMA_CFG);
 }
 
-- 
2.40.1

[PATCH v4 11/11] drm/mediatek: gamma: Program gamma LUT type for descending or rising

[AngeloGioacchino Del Regno]

All of the SoCs that don't have dithering control in the gamma IP
have got a GAMMA_LUT_TYPE bit that tells to the IP if the LUT is
"descending" (bit set) or "rising" (bit cleared): make sure to set
it correctly after programming the LUT.

Signed-off-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Reviewed-by: Jason-JH.Lin <jason-jh.lin@mediatek.com>
---
 drivers/gpu/drm/mediatek/mtk_disp_gamma.c | 19 +++++++++++++++++++
 1 file changed, 19 insertions(+)

diff --git a/drivers/gpu/drm/mediatek/mtk_disp_gamma.c b/drivers/gpu/drm/mediatek/mtk_disp_gamma.c
index ba8a0f93f184..d7c7c6ca2e97 100644
--- a/drivers/gpu/drm/mediatek/mtk_disp_gamma.c
+++ b/drivers/gpu/drm/mediatek/mtk_disp_gamma.c
@@ -23,6 +23,7 @@
 #define GAMMA_RELAY_MODE				BIT(0)
 #define GAMMA_LUT_EN					BIT(1)
 #define GAMMA_DITHERING					BIT(2)
+#define GAMMA_LUT_TYPE					BIT(2)
 #define DISP_GAMMA_SIZE				0x0030
 #define DISP_GAMMA_SIZE_HSIZE				GENMASK(28, 16)
 #define DISP_GAMMA_SIZE_VSIZE				GENMASK(12, 0)
@@ -89,6 +90,16 @@ unsigned int mtk_gamma_get_lut_size(struct device *dev)
 	return lut_size;
 }
 
+static bool mtk_gamma_lut_is_descending(struct drm_color_lut *lut, u32 lut_size)
+{
+	u64 first, last;
+
+	first = lut[0].red + lut[0].green + lut[0].blue;
+	last = lut[lut_size].red + lut[lut_size].green + lut[lut_size].blue;
+
+	return !!(first > last);
+}
+
 void mtk_gamma_set_common(struct device *dev, void __iomem *regs, struct drm_crtc_state *state)
 {
 	struct mtk_disp_gamma *gamma = dev_get_drvdata(dev);
@@ -182,6 +193,14 @@ void mtk_gamma_set_common(struct device *dev, void __iomem *regs, struct drm_crt
 		}
 	}
 
+	if (gamma && !gamma->data->has_dither) {
+		/* Descending or Rising LUT */
+		if (mtk_gamma_lut_is_descending(lut, lut_size))
+			cfg_val |= FIELD_PREP(GAMMA_LUT_TYPE, 1);
+		else
+			cfg_val &= ~GAMMA_LUT_TYPE;
+	}
+
 	/* Enable the gamma table */
 	cfg_val |= FIELD_PREP(GAMMA_LUT_EN, 1);
 
-- 
2.40.1