[PATCHv6 7/8] drm/i915/histogram: Histogram changes for Display 20+

[PATCHv6 7/8] drm/i915/histogram: Histogram changes for Display 20+

[Arun R Murthy]

In Display 20+, new registers are added for setting index, reading
histogram and writing the IET.

v2: Removed duplicate code (Jani)
v3: Moved histogram core changes to earlier patches (Jani/Suraj)
v4: Rebased after addressing comments on patch 1
v5: Added the retry logic from patch3 and rebased the patch series
v6: optimize wite_iet() (Suraj)

Signed-off-by: Arun R Murthy <arun.r.murthy@intel.com>
---
 .../gpu/drm/i915/display/intel_histogram.c    | 105 +++++++++++++-----
 .../drm/i915/display/intel_histogram_regs.h   |  25 +++++
 2 files changed, 103 insertions(+), 27 deletions(-)

diff --git a/drivers/gpu/drm/i915/display/intel_histogram.c b/drivers/gpu/drm/i915/display/intel_histogram.c
index a64e778fface..db4bc60be557 100644
--- a/drivers/gpu/drm/i915/display/intel_histogram.c
+++ b/drivers/gpu/drm/i915/display/intel_histogram.c
@@ -29,6 +29,37 @@ struct intel_histogram {
 	u32 bin_data[HISTOGRAM_BIN_COUNT];
 };
 
+static void set_bin_index_0(struct intel_display *display, enum pipe pipe)
+{
+	if (DISPLAY_VER(display) >= 20)
+		intel_de_rmw(display, DPST_IE_INDEX(pipe),
+			     DPST_IE_BIN_INDEX_MASK, DPST_IE_BIN_INDEX(0));
+	else
+		intel_de_rmw(display, DPST_CTL(pipe),
+			     DPST_CTL_BIN_REG_MASK,
+			     DPST_CTL_BIN_REG_CLEAR);
+}
+
+static void write_iet(struct intel_display *display, enum pipe pipe,
+			      u32 *data)
+{
+	int i;
+
+	for (i = 0; i < HISTOGRAM_IET_LENGTH; i++) {
+		if (DISPLAY_VER(display) >= 20)
+			intel_de_rmw(display, DPST_IE_BIN(pipe),
+				     DPST_IE_BIN_DATA_MASK,
+				     DPST_IE_BIN_DATA(data[i]));
+		else
+			intel_de_rmw(display, DPST_BIN(pipe),
+				     DPST_BIN_DATA_MASK,
+				     DPST_BIN_DATA(data[i]));
+
+		drm_dbg_atomic(display->drm, "iet_lut[%d]=%x\n",
+			       i, data[i]);
+	}
+}
+
 static bool intel_histogram_get_data(struct intel_crtc *intel_crtc)
 {
 	struct intel_display *display = to_intel_display(intel_crtc);
@@ -36,12 +67,27 @@ static bool intel_histogram_get_data(struct intel_crtc *intel_crtc)
 	int index;
 	u32 dpstbin;
 
+	if (DISPLAY_VER(display) >= 20)
+		intel_de_rmw(display, DPST_HIST_INDEX(intel_crtc->pipe),
+			     DPST_HIST_BIN_INDEX_MASK,
+			     DPST_HIST_BIN_INDEX(0));
+	else
+		intel_de_rmw(display, DPST_CTL(intel_crtc->pipe),
+			     DPST_CTL_BIN_REG_FUNC_SEL | DPST_CTL_BIN_REG_MASK, 0);
+
 	for (index = 0; index < ARRAY_SIZE(histogram->bin_data); index++) {
-		dpstbin = intel_de_read(display, DPST_BIN(intel_crtc->pipe));
+		dpstbin = intel_de_read(display, (DISPLAY_VER(display) >= 20 ?
+					DPST_HIST_BIN(intel_crtc->pipe) :
+					DPST_BIN(intel_crtc->pipe)));
 		if (!(dpstbin & DPST_BIN_BUSY)) {
-			histogram->bin_data[index] = dpstbin & DPST_BIN_DATA_MASK;
-		} else
+			histogram->bin_data[index] = dpstbin & (DISPLAY_VER(display) >= 20 ?
+								DPST_HIST_BIN_DATA_MASK :
+								DPST_BIN_DATA_MASK);
+		} else {
+			drm_err(display->drm, "Histogram bin busy, retyring\n");
+			fsleep(2);
 			return false;
+		}
 	}
 	return true;
 }
@@ -69,8 +115,6 @@ static void intel_histogram_handle_int_work(struct work_struct *work)
 	 * Set DPST_CTL Bin Reg function select to TC
 	 * Set DPST_CTL Bin Register Index to 0
 	 */
-	intel_de_rmw(display, DPST_CTL(intel_crtc->pipe),
-		     DPST_CTL_BIN_REG_FUNC_SEL | DPST_CTL_BIN_REG_MASK, 0);
 	for (retry = 0; retry < HISTOGRAM_BIN_READ_RETRY_COUNT; retry++) {
 		if (intel_histogram_get_data(intel_crtc)) {
 			drm_property_replace_global_blob(display->drm,
@@ -153,15 +197,26 @@ static int intel_histogram_enable(struct intel_crtc *intel_crtc)
 	if (histogram->enable)
 		return 0;
 
-	 /* enable histogram, clear DPST_CTL bin reg func select to TC */
-	intel_de_rmw(display, DPST_CTL(pipe),
-		     DPST_CTL_BIN_REG_FUNC_SEL | DPST_CTL_IE_HIST_EN |
-		     DPST_CTL_HIST_MODE | DPST_CTL_IE_TABLE_VALUE_FORMAT |
-		     DPST_CTL_ENHANCEMENT_MODE_MASK | DPST_CTL_IE_MODI_TABLE_EN,
-		     DPST_CTL_BIN_REG_FUNC_TC | DPST_CTL_IE_HIST_EN |
-		     DPST_CTL_HIST_MODE_HSV |
-		     DPST_CTL_IE_TABLE_VALUE_FORMAT_1INT_9FRAC |
-		     DPST_CTL_EN_MULTIPLICATIVE | DPST_CTL_IE_MODI_TABLE_EN);
+	 /* enable histogram, clear DPST_BIN reg and select TC function */
+	if (DISPLAY_VER(display) >= 20)
+		intel_de_rmw(display, DPST_CTL(pipe),
+			     DPST_CTL_IE_HIST_EN |
+			     DPST_CTL_HIST_MODE,
+			     DPST_CTL_IE_HIST_EN |
+			     DPST_CTL_HIST_MODE_HSV);
+	else
+		 /* enable histogram, clear DPST_BIN reg and select TC function */
+		intel_de_rmw(display, DPST_CTL(pipe),
+			     DPST_CTL_BIN_REG_FUNC_SEL | DPST_CTL_IE_HIST_EN |
+			     DPST_CTL_HIST_MODE |
+			     DPST_CTL_IE_TABLE_VALUE_FORMAT |
+			     DPST_CTL_ENHANCEMENT_MODE_MASK |
+			     DPST_CTL_IE_MODI_TABLE_EN,
+			     DPST_CTL_BIN_REG_FUNC_TC | DPST_CTL_IE_HIST_EN |
+			     DPST_CTL_HIST_MODE_HSV |
+			     DPST_CTL_IE_TABLE_VALUE_FORMAT_1INT_9FRAC |
+			     DPST_CTL_EN_MULTIPLICATIVE |
+			     DPST_CTL_IE_MODI_TABLE_EN);
 
 	/* Re-Visit: check if wait for one vblank is required */
 	drm_crtc_wait_one_vblank(&intel_crtc->base);
@@ -230,7 +285,6 @@ int intel_histogram_set_iet_lut(struct intel_crtc *intel_crtc, u32 *data)
 	struct intel_histogram *histogram = intel_crtc->histogram;
 	struct intel_display *display = to_intel_display(intel_crtc);
 	int pipe = intel_crtc->pipe;
-	int i = 0;
 
 	if (!histogram)
 		return -EINVAL;
@@ -245,22 +299,19 @@ int intel_histogram_set_iet_lut(struct intel_crtc *intel_crtc, u32 *data)
 		return -EINVAL;
 	}
 
-	/* Set DPST_CTL Bin Reg function select to IE & wait for a vblabk */
-	intel_de_rmw(display, DPST_CTL(pipe),
-		     DPST_CTL_BIN_REG_FUNC_SEL, DPST_CTL_BIN_REG_FUNC_IE);
 
-	drm_crtc_wait_one_vblank(&intel_crtc->base);
+	if (DISPLAY_VER(display) < 20) {
+		/* Set DPST_CTL Bin Reg function select to IE & wait for a vblabk */
+		intel_de_rmw(display, DPST_CTL(pipe),
+			     DPST_CTL_BIN_REG_FUNC_SEL,
+			     DPST_CTL_BIN_REG_FUNC_IE);
 
-	 /* Set DPST_CTL Bin Register Index to 0 */
-	intel_de_rmw(display, DPST_CTL(pipe),
-		     DPST_CTL_BIN_REG_MASK, DPST_CTL_BIN_REG_CLEAR);
-
-	for (i = 0; i < HISTOGRAM_IET_LENGTH; i++) {
-		intel_de_rmw(display, DPST_BIN(pipe),
-			     DPST_BIN_DATA_MASK, data[i]);
-		drm_dbg_atomic(display->drm, "iet_lut[%d]=%x\n", i, data[i]);
+		drm_crtc_wait_one_vblank(&intel_crtc->base);
 	}
 
+	set_bin_index_0(display, pipe);
+	write_iet(display, pipe, data);
+
 	return 0;
 }
 
diff --git a/drivers/gpu/drm/i915/display/intel_histogram_regs.h b/drivers/gpu/drm/i915/display/intel_histogram_regs.h
index 213c9f483567..3fbb9c2deaae 100644
--- a/drivers/gpu/drm/i915/display/intel_histogram_regs.h
+++ b/drivers/gpu/drm/i915/display/intel_histogram_regs.h
@@ -45,6 +45,31 @@
 #define _DPST_BIN_B					0x491C4
 #define DPST_BIN(pipe)					_MMIO_PIPE(pipe, _DPST_BIN_A, _DPST_BIN_B)
 #define  DPST_BIN_DATA_MASK				REG_GENMASK(23, 0)
+#define  DPST_BIN_DATA(val)				REG_FIELD_PREP(DPST_BIN_DATA_MASK, val)
 #define  DPST_BIN_BUSY					REG_BIT(31)
 
+#define _DPST_HIST_INDEX_A				0x490D8
+#define _DPST_HIST_INDEX_B				0x491D8
+#define DPST_HIST_INDEX(pipe)				_MMIO_PIPE(pipe, _DPST_HIST_INDEX_A, _DPST_HIST_INDEX_B)
+#define  DPST_HIST_BIN_INDEX_MASK			REG_GENMASK(4, 0)
+#define  DPST_HIST_BIN_INDEX(val)			REG_FIELD_PREP(DPST_HIST_BIN_INDEX_MASK, val)
+
+#define _DPST_HIST_BIN_A				0x490C4
+#define _DPST_HIST_BIN_B				0x491C4
+#define DPST_HIST_BIN(pipe)				_MMIO_PIPE(pipe, _DPST_HIST_BIN_A, _DPST_HIST_BIN_B)
+#define  DPST_HIST_BIN_BUSY				REG_BIT(31)
+#define  DPST_HIST_BIN_DATA_MASK				REG_GENMASK(30, 0)
+
+#define _DPST_IE_BIN_A					0x490CC
+#define _DPST_IE_BIN_B					0x491CC
+#define DPST_IE_BIN(pipe)				_MMIO_PIPE(pipe, _DPST_IE_BIN_A, _DPST_IE_BIN_B)
+#define	 DPST_IE_BIN_DATA_MASK				REG_GENMASK(9, 0)
+#define  DPST_IE_BIN_DATA(val)				REG_FIELD_PREP(DPST_IE_BIN_DATA_MASK, val)
+
+#define _DPST_IE_INDEX_A				0x490DC
+#define _DPST_IE_INDEX_B				0x491DC
+#define DPST_IE_INDEX(pipe)				_MMIO_PIPE(pipe, _DPST_IE_INDEX_A, _DPST_IE_INDEX_B)
+#define  DPST_IE_BIN_INDEX_MASK				REG_GENMASK(6, 0)
+#define  DPST_IE_BIN_INDEX(val)				REG_FIELD_PREP(DPST_IE_BIN_INDEX_MASK, val)
+
 #endif /* __INTEL_HISTOGRAM_REGS_H__ */
-- 
2.25.1

RE: [PATCHv6 7/8] drm/i915/histogram: Histogram changes for Display 20+

[Kandpal, Suraj]

> -----Original Message-----
> From: dri-devel <dri-devel-bounces@lists.freedesktop.org> On Behalf Of
> Arun R Murthy
> Sent: Thursday, November 21, 2024 5:56 PM
> To: intel-xe@lists.freedesktop.org; intel-gfx@lists.freedesktop.org; dri-
> devel@lists.freedesktop.org
> Cc: Murthy, Arun R <arun.r.murthy@intel.com>
> Subject: [PATCHv6 7/8] drm/i915/histogram: Histogram changes for Display
> 20+
> 
> In Display 20+, new registers are added for setting index, reading histogram
> and writing the IET.
> 
> v2: Removed duplicate code (Jani)
> v3: Moved histogram core changes to earlier patches (Jani/Suraj)
> v4: Rebased after addressing comments on patch 1
> v5: Added the retry logic from patch3 and rebased the patch series
> v6: optimize wite_iet() (Suraj)

I think you missed some comments from previous revision
Add the bspec reference for registers added

> 
> Signed-off-by: Arun R Murthy <arun.r.murthy@intel.com>
> ---
>  .../gpu/drm/i915/display/intel_histogram.c    | 105 +++++++++++++-----
>  .../drm/i915/display/intel_histogram_regs.h   |  25 +++++
>  2 files changed, 103 insertions(+), 27 deletions(-)
> 
> diff --git a/drivers/gpu/drm/i915/display/intel_histogram.c
> b/drivers/gpu/drm/i915/display/intel_histogram.c
> index a64e778fface..db4bc60be557 100644
> --- a/drivers/gpu/drm/i915/display/intel_histogram.c
> +++ b/drivers/gpu/drm/i915/display/intel_histogram.c
> @@ -29,6 +29,37 @@ struct intel_histogram {
>  	u32 bin_data[HISTOGRAM_BIN_COUNT];
>  };
> 
> +static void set_bin_index_0(struct intel_display *display, enum pipe
> +pipe) {
> +	if (DISPLAY_VER(display) >= 20)
> +		intel_de_rmw(display, DPST_IE_INDEX(pipe),
> +			     DPST_IE_BIN_INDEX_MASK,
> DPST_IE_BIN_INDEX(0));
> +	else
> +		intel_de_rmw(display, DPST_CTL(pipe),
> +			     DPST_CTL_BIN_REG_MASK,
> +			     DPST_CTL_BIN_REG_CLEAR);
> +}
> +
> +static void write_iet(struct intel_display *display, enum pipe pipe,
> +			      u32 *data)
> +{
> +	int i;
> +
> +	for (i = 0; i < HISTOGRAM_IET_LENGTH; i++) {
> +		if (DISPLAY_VER(display) >= 20)
> +			intel_de_rmw(display, DPST_IE_BIN(pipe),
> +				     DPST_IE_BIN_DATA_MASK,
> +				     DPST_IE_BIN_DATA(data[i]));
> +		else
> +			intel_de_rmw(display, DPST_BIN(pipe),
> +				     DPST_BIN_DATA_MASK,
> +				     DPST_BIN_DATA(data[i]));
> +
> +		drm_dbg_atomic(display->drm, "iet_lut[%d]=%x\n",
> +			       i, data[i]);
> +	}

This looks more clean according to me 
if (DISPLAY_VER(display) >= 20) {
    register_base = DPST_IE_BIN(pipe);
    data_mask = DPST_IE_BIN_DATA_MASK;
    data_temp = DPST_IE_BIN_DATA(data[i]);
} else {
    register_base = DPST_BIN(pipe);
    data_mask = DPST_BIN_DATA_MASK;
    data_temp = DPST_BIN_DATA(data[i]);
}
 intel_de_rmw(display, register_base, data_mask, data_temp);
  drm_dbg_atomic(display->drm, "iet_lut[%d]=%x\n", i, data[i]);

The rest LGTM
So with the above comments addressed 
Reviewed-by: Suraj Kandpal <suraj.kandpal@intel.com>



> +}
> +
>  static bool intel_histogram_get_data(struct intel_crtc *intel_crtc)  {
>  	struct intel_display *display = to_intel_display(intel_crtc); @@ -36,12
> +67,27 @@ static bool intel_histogram_get_data(struct intel_crtc *intel_crtc)
>  	int index;
>  	u32 dpstbin;
> 
> +	if (DISPLAY_VER(display) >= 20)
> +		intel_de_rmw(display, DPST_HIST_INDEX(intel_crtc->pipe),
> +			     DPST_HIST_BIN_INDEX_MASK,
> +			     DPST_HIST_BIN_INDEX(0));
> +	else
> +		intel_de_rmw(display, DPST_CTL(intel_crtc->pipe),
> +			     DPST_CTL_BIN_REG_FUNC_SEL |
> DPST_CTL_BIN_REG_MASK, 0);
> +
>  	for (index = 0; index < ARRAY_SIZE(histogram->bin_data); index++) {
> -		dpstbin = intel_de_read(display, DPST_BIN(intel_crtc->pipe));
> +		dpstbin = intel_de_read(display, (DISPLAY_VER(display) >= 20
> ?
> +					DPST_HIST_BIN(intel_crtc->pipe) :
> +					DPST_BIN(intel_crtc->pipe)));
>  		if (!(dpstbin & DPST_BIN_BUSY)) {
> -			histogram->bin_data[index] = dpstbin &
> DPST_BIN_DATA_MASK;
> -		} else
> +			histogram->bin_data[index] = dpstbin &
> (DISPLAY_VER(display) >= 20 ?
> +
> 	DPST_HIST_BIN_DATA_MASK :
> +
> 	DPST_BIN_DATA_MASK);
> +		} else {
> +			drm_err(display->drm, "Histogram bin busy,
> retyring\n");
> +			fsleep(2);
>  			return false;
> +		}
>  	}
>  	return true;
>  }
> @@ -69,8 +115,6 @@ static void intel_histogram_handle_int_work(struct
> work_struct *work)
>  	 * Set DPST_CTL Bin Reg function select to TC
>  	 * Set DPST_CTL Bin Register Index to 0
>  	 */
> -	intel_de_rmw(display, DPST_CTL(intel_crtc->pipe),
> -		     DPST_CTL_BIN_REG_FUNC_SEL |
> DPST_CTL_BIN_REG_MASK, 0);
>  	for (retry = 0; retry < HISTOGRAM_BIN_READ_RETRY_COUNT; retry++)
> {
>  		if (intel_histogram_get_data(intel_crtc)) {
>  			drm_property_replace_global_blob(display->drm,
> @@ -153,15 +197,26 @@ static int intel_histogram_enable(struct intel_crtc
> *intel_crtc)
>  	if (histogram->enable)
>  		return 0;
> 
> -	 /* enable histogram, clear DPST_CTL bin reg func select to TC */
> -	intel_de_rmw(display, DPST_CTL(pipe),
> -		     DPST_CTL_BIN_REG_FUNC_SEL | DPST_CTL_IE_HIST_EN |
> -		     DPST_CTL_HIST_MODE |
> DPST_CTL_IE_TABLE_VALUE_FORMAT |
> -		     DPST_CTL_ENHANCEMENT_MODE_MASK |
> DPST_CTL_IE_MODI_TABLE_EN,
> -		     DPST_CTL_BIN_REG_FUNC_TC | DPST_CTL_IE_HIST_EN |
> -		     DPST_CTL_HIST_MODE_HSV |
> -		     DPST_CTL_IE_TABLE_VALUE_FORMAT_1INT_9FRAC |
> -		     DPST_CTL_EN_MULTIPLICATIVE |
> DPST_CTL_IE_MODI_TABLE_EN);
> +	 /* enable histogram, clear DPST_BIN reg and select TC function */
> +	if (DISPLAY_VER(display) >= 20)
> +		intel_de_rmw(display, DPST_CTL(pipe),
> +			     DPST_CTL_IE_HIST_EN |
> +			     DPST_CTL_HIST_MODE,
> +			     DPST_CTL_IE_HIST_EN |
> +			     DPST_CTL_HIST_MODE_HSV);
> +	else
> +		 /* enable histogram, clear DPST_BIN reg and select TC
> function */
> +		intel_de_rmw(display, DPST_CTL(pipe),
> +			     DPST_CTL_BIN_REG_FUNC_SEL |
> DPST_CTL_IE_HIST_EN |
> +			     DPST_CTL_HIST_MODE |
> +			     DPST_CTL_IE_TABLE_VALUE_FORMAT |
> +			     DPST_CTL_ENHANCEMENT_MODE_MASK |
> +			     DPST_CTL_IE_MODI_TABLE_EN,
> +			     DPST_CTL_BIN_REG_FUNC_TC |
> DPST_CTL_IE_HIST_EN |
> +			     DPST_CTL_HIST_MODE_HSV |
> +			     DPST_CTL_IE_TABLE_VALUE_FORMAT_1INT_9FRAC
> |
> +			     DPST_CTL_EN_MULTIPLICATIVE |
> +			     DPST_CTL_IE_MODI_TABLE_EN);
> 
>  	/* Re-Visit: check if wait for one vblank is required */
>  	drm_crtc_wait_one_vblank(&intel_crtc->base);
> @@ -230,7 +285,6 @@ int intel_histogram_set_iet_lut(struct intel_crtc
> *intel_crtc, u32 *data)
>  	struct intel_histogram *histogram = intel_crtc->histogram;
>  	struct intel_display *display = to_intel_display(intel_crtc);
>  	int pipe = intel_crtc->pipe;
> -	int i = 0;
> 
>  	if (!histogram)
>  		return -EINVAL;
> @@ -245,22 +299,19 @@ int intel_histogram_set_iet_lut(struct intel_crtc
> *intel_crtc, u32 *data)
>  		return -EINVAL;
>  	}
> 
> -	/* Set DPST_CTL Bin Reg function select to IE & wait for a vblabk */
> -	intel_de_rmw(display, DPST_CTL(pipe),
> -		     DPST_CTL_BIN_REG_FUNC_SEL,
> DPST_CTL_BIN_REG_FUNC_IE);
> 
> -	drm_crtc_wait_one_vblank(&intel_crtc->base);
> +	if (DISPLAY_VER(display) < 20) {
> +		/* Set DPST_CTL Bin Reg function select to IE & wait for a
> vblabk */
> +		intel_de_rmw(display, DPST_CTL(pipe),
> +			     DPST_CTL_BIN_REG_FUNC_SEL,
> +			     DPST_CTL_BIN_REG_FUNC_IE);
> 
> -	 /* Set DPST_CTL Bin Register Index to 0 */
> -	intel_de_rmw(display, DPST_CTL(pipe),
> -		     DPST_CTL_BIN_REG_MASK, DPST_CTL_BIN_REG_CLEAR);
> -
> -	for (i = 0; i < HISTOGRAM_IET_LENGTH; i++) {
> -		intel_de_rmw(display, DPST_BIN(pipe),
> -			     DPST_BIN_DATA_MASK, data[i]);
> -		drm_dbg_atomic(display->drm, "iet_lut[%d]=%x\n", i,
> data[i]);
> +		drm_crtc_wait_one_vblank(&intel_crtc->base);
>  	}
> 
> +	set_bin_index_0(display, pipe);
> +	write_iet(display, pipe, data);
> +
>  	return 0;
>  }
> 
> diff --git a/drivers/gpu/drm/i915/display/intel_histogram_regs.h
> b/drivers/gpu/drm/i915/display/intel_histogram_regs.h
> index 213c9f483567..3fbb9c2deaae 100644
> --- a/drivers/gpu/drm/i915/display/intel_histogram_regs.h
> +++ b/drivers/gpu/drm/i915/display/intel_histogram_regs.h
> @@ -45,6 +45,31 @@
>  #define _DPST_BIN_B					0x491C4
>  #define DPST_BIN(pipe)
> 	_MMIO_PIPE(pipe, _DPST_BIN_A, _DPST_BIN_B)
>  #define  DPST_BIN_DATA_MASK
> 	REG_GENMASK(23, 0)
> +#define  DPST_BIN_DATA(val)
> 	REG_FIELD_PREP(DPST_BIN_DATA_MASK, val)
>  #define  DPST_BIN_BUSY					REG_BIT(31)
> 
> +#define _DPST_HIST_INDEX_A				0x490D8
> +#define _DPST_HIST_INDEX_B				0x491D8
> +#define DPST_HIST_INDEX(pipe)
> 	_MMIO_PIPE(pipe, _DPST_HIST_INDEX_A, _DPST_HIST_INDEX_B)
> +#define  DPST_HIST_BIN_INDEX_MASK
> 	REG_GENMASK(4, 0)
> +#define  DPST_HIST_BIN_INDEX(val)
> 	REG_FIELD_PREP(DPST_HIST_BIN_INDEX_MASK, val)
> +
> +#define _DPST_HIST_BIN_A				0x490C4
> +#define _DPST_HIST_BIN_B				0x491C4
> +#define DPST_HIST_BIN(pipe)				_MMIO_PIPE(pipe,
> _DPST_HIST_BIN_A, _DPST_HIST_BIN_B)
> +#define  DPST_HIST_BIN_BUSY				REG_BIT(31)
> +#define  DPST_HIST_BIN_DATA_MASK
> 	REG_GENMASK(30, 0)
> +
> +#define _DPST_IE_BIN_A					0x490CC
> +#define _DPST_IE_BIN_B					0x491CC
> +#define DPST_IE_BIN(pipe)				_MMIO_PIPE(pipe,
> _DPST_IE_BIN_A, _DPST_IE_BIN_B)
> +#define	 DPST_IE_BIN_DATA_MASK
> 	REG_GENMASK(9, 0)
> +#define  DPST_IE_BIN_DATA(val)
> 	REG_FIELD_PREP(DPST_IE_BIN_DATA_MASK, val)
> +
> +#define _DPST_IE_INDEX_A				0x490DC
> +#define _DPST_IE_INDEX_B				0x491DC
> +#define DPST_IE_INDEX(pipe)				_MMIO_PIPE(pipe,
> _DPST_IE_INDEX_A, _DPST_IE_INDEX_B)
> +#define  DPST_IE_BIN_INDEX_MASK
> 	REG_GENMASK(6, 0)
> +#define  DPST_IE_BIN_INDEX(val)
> 	REG_FIELD_PREP(DPST_IE_BIN_INDEX_MASK, val)
> +
>  #endif /* __INTEL_HISTOGRAM_REGS_H__ */
> --
> 2.25.1

[PATCHv5 2/8] drm/i915/histogram: Add support for histogram

[Arun R Murthy]

Statistics is generated from the image frame that is coming to display
and an event is sent to user after reading this histogram data.
This statistics/histogram is then shared with the user upon getting a
request from user. User can then use this histogram and generate an
enhancement factor. This enhancement factor can be multiplied/added with
the incoming pixel data frame.

v2: forward declaration in header file along with error handling (Jani)
v3: Replaced i915 with intel_display (Suraj)
v4: Removed dithering enable/disable (Vandita)
    New patch for histogram register definitions (Suraj)
v5: IET LUT pgm follow the seq in spec and removed change to TC at end
    (Suraj)

Signed-off-by: Arun R Murthy <arun.r.murthy@intel.com>
Reviewed-by: Suraj Kandpal <suraj.kandpal@intel.com>
---
 drivers/gpu/drm/i915/Makefile                 |   1 +
 .../drm/i915/display/intel_display_types.h    |   2 +
 .../gpu/drm/i915/display/intel_histogram.c    | 187 ++++++++++++++++++
 .../gpu/drm/i915/display/intel_histogram.h    |  35 ++++
 4 files changed, 225 insertions(+)
 create mode 100644 drivers/gpu/drm/i915/display/intel_histogram.c
 create mode 100644 drivers/gpu/drm/i915/display/intel_histogram.h

diff --git a/drivers/gpu/drm/i915/Makefile b/drivers/gpu/drm/i915/Makefile
index e465828d748f..97141b4def3b 100644
--- a/drivers/gpu/drm/i915/Makefile
+++ b/drivers/gpu/drm/i915/Makefile
@@ -267,6 +267,7 @@ i915-y += \
 	display/intel_hdcp.o \
 	display/intel_hdcp_gsc.o \
 	display/intel_hdcp_gsc_message.o \
+	display/intel_histogram.o \
 	display/intel_hotplug.o \
 	display/intel_hotplug_irq.o \
 	display/intel_hti.o \
diff --git a/drivers/gpu/drm/i915/display/intel_display_types.h b/drivers/gpu/drm/i915/display/intel_display_types.h
index 339e4b0f7698..351441efd10a 100644
--- a/drivers/gpu/drm/i915/display/intel_display_types.h
+++ b/drivers/gpu/drm/i915/display/intel_display_types.h
@@ -1414,6 +1414,8 @@ struct intel_crtc {
 	/* for loading single buffered registers during vblank */
 	struct pm_qos_request vblank_pm_qos;
 
+	struct intel_histogram *histogram;
+
 #ifdef CONFIG_DEBUG_FS
 	struct intel_pipe_crc pipe_crc;
 #endif
diff --git a/drivers/gpu/drm/i915/display/intel_histogram.c b/drivers/gpu/drm/i915/display/intel_histogram.c
new file mode 100644
index 000000000000..12b70936c91c
--- /dev/null
+++ b/drivers/gpu/drm/i915/display/intel_histogram.c
@@ -0,0 +1,187 @@
+// SPDX-License-Identifier: MIT
+/*
+ * Copyright © 2024 Intel Corporation
+ */
+
+#include <drm/drm_device.h>
+#include <drm/drm_file.h>
+#include <drm/drm_vblank.h>
+
+#include "i915_reg.h"
+#include "i915_drv.h"
+#include "intel_de.h"
+#include "intel_display.h"
+#include "intel_display_types.h"
+#include "intel_histogram.h"
+#include "intel_histogram_regs.h"
+
+/* 3.0% of the pipe's current pixel count, hw does x4 */
+#define HISTOGRAM_GUARDBAND_THRESHOLD_DEFAULT 300
+/* Precision factor for threshold guardband */
+#define HISTOGRAM_GUARDBAND_PRECISION_FACTOR 10000
+#define HISTOGRAM_DEFAULT_GUARDBAND_DELAY 0x04
+
+struct intel_histogram {
+	struct intel_crtc *crtc;
+	struct delayed_work work;
+	bool enable;
+	bool can_enable;
+	u32 bin_data[HISTOGRAM_BIN_COUNT];
+};
+
+int intel_histogram_atomic_check(struct intel_crtc *intel_crtc)
+{
+	struct intel_histogram *histogram = intel_crtc->histogram;
+
+	/* TODO: Restrictions for enabling histogram */
+	histogram->can_enable = true;
+
+	return 0;
+}
+
+static int intel_histogram_enable(struct intel_crtc *intel_crtc)
+{
+	struct intel_display *display = to_intel_display(intel_crtc);
+	struct intel_histogram *histogram = intel_crtc->histogram;
+	int pipe = intel_crtc->pipe;
+	u64 res;
+	u32 gbandthreshold;
+
+	if (!histogram || !histogram->can_enable)
+		return -EINVAL;
+
+	if (histogram->enable)
+		return 0;
+
+	 /* enable histogram, clear DPST_CTL bin reg func select to TC */
+	intel_de_rmw(display, DPST_CTL(pipe),
+		     DPST_CTL_BIN_REG_FUNC_SEL | DPST_CTL_IE_HIST_EN |
+		     DPST_CTL_HIST_MODE | DPST_CTL_IE_TABLE_VALUE_FORMAT |
+		     DPST_CTL_ENHANCEMENT_MODE_MASK | DPST_CTL_IE_MODI_TABLE_EN,
+		     DPST_CTL_BIN_REG_FUNC_TC | DPST_CTL_IE_HIST_EN |
+		     DPST_CTL_HIST_MODE_HSV |
+		     DPST_CTL_IE_TABLE_VALUE_FORMAT_1INT_9FRAC |
+		     DPST_CTL_EN_MULTIPLICATIVE | DPST_CTL_IE_MODI_TABLE_EN);
+
+	/* Re-Visit: check if wait for one vblank is required */
+	drm_crtc_wait_one_vblank(&intel_crtc->base);
+
+	/* TODO: Program GuardBand Threshold needs to be moved to modeset path */
+	res = (intel_crtc->config->hw.adjusted_mode.vtotal *
+	       intel_crtc->config->hw.adjusted_mode.htotal);
+
+	gbandthreshold = (res *	HISTOGRAM_GUARDBAND_THRESHOLD_DEFAULT) /
+			  HISTOGRAM_GUARDBAND_PRECISION_FACTOR;
+
+	/* Enable histogram interrupt mode */
+	intel_de_rmw(display, DPST_GUARD(pipe),
+		     DPST_GUARD_THRESHOLD_GB_MASK |
+		     DPST_GUARD_INTERRUPT_DELAY_MASK | DPST_GUARD_HIST_INT_EN,
+		     DPST_GUARD_THRESHOLD_GB(gbandthreshold) |
+		     DPST_GUARD_INTERRUPT_DELAY(HISTOGRAM_DEFAULT_GUARDBAND_DELAY) |
+		     DPST_GUARD_HIST_INT_EN);
+
+	/* Clear pending interrupts has to be done on separate write */
+	intel_de_rmw(display, DPST_GUARD(pipe),
+		     DPST_GUARD_HIST_EVENT_STATUS, 1);
+
+	histogram->enable = true;
+
+	return 0;
+}
+
+static void intel_histogram_disable(struct intel_crtc *intel_crtc)
+{
+	struct intel_display *display = to_intel_display(intel_crtc);
+	struct intel_histogram *histogram = intel_crtc->histogram;
+	int pipe = intel_crtc->pipe;
+
+	if (!histogram)
+		return;
+
+	/* If already disabled return */
+	if (histogram->enable)
+		return;
+
+	/* Clear pending interrupts and disable interrupts */
+	intel_de_rmw(display, DPST_GUARD(pipe),
+		     DPST_GUARD_HIST_INT_EN | DPST_GUARD_HIST_EVENT_STATUS, 0);
+
+	/* disable DPST_CTL Histogram mode */
+	intel_de_rmw(display, DPST_CTL(pipe),
+		     DPST_CTL_IE_HIST_EN, 0);
+
+	histogram->enable = false;
+}
+
+int intel_histogram_update(struct intel_crtc *intel_crtc, bool enable)
+{
+	if (enable)
+		return intel_histogram_enable(intel_crtc);
+
+	intel_histogram_disable(intel_crtc);
+	return 0;
+}
+
+int intel_histogram_set_iet_lut(struct intel_crtc *intel_crtc, u32 *data)
+{
+	struct intel_histogram *histogram = intel_crtc->histogram;
+	struct intel_display *display = to_intel_display(intel_crtc);
+	int pipe = intel_crtc->pipe;
+	int i = 0;
+
+	if (!histogram)
+		return -EINVAL;
+
+	if (!histogram->enable) {
+		drm_err(display->drm, "histogram not enabled");
+		return -EINVAL;
+	}
+
+	if (!data) {
+		drm_err(display->drm, "enhancement LUT data is NULL");
+		return -EINVAL;
+	}
+
+	/* Set DPST_CTL Bin Reg function select to IE & wait for a vblabk */
+	intel_de_rmw(display, DPST_CTL(pipe),
+		     DPST_CTL_BIN_REG_FUNC_SEL, DPST_CTL_BIN_REG_FUNC_IE);
+
+	drm_crtc_wait_one_vblank(&intel_crtc->base);
+
+	 /* Set DPST_CTL Bin Register Index to 0 */
+	intel_de_rmw(display, DPST_CTL(pipe),
+		     DPST_CTL_BIN_REG_MASK, DPST_CTL_BIN_REG_CLEAR);
+
+	for (i = 0; i < HISTOGRAM_IET_LENGTH; i++) {
+		intel_de_rmw(display, DPST_BIN(pipe),
+			     DPST_BIN_DATA_MASK, data[i]);
+		drm_dbg_atomic(display->drm, "iet_lut[%d]=%x\n", i, data[i]);
+	}
+
+	return 0;
+}
+
+void intel_histogram_finish(struct intel_crtc *intel_crtc)
+{
+	struct intel_histogram *histogram = intel_crtc->histogram;
+
+	kfree(histogram);
+}
+
+int intel_histogram_init(struct intel_crtc *intel_crtc)
+{
+	struct intel_histogram *histogram;
+
+	/* Allocate histogram internal struct */
+	histogram = kzalloc(sizeof(*histogram), GFP_KERNEL);
+	if (!histogram) {
+		return -ENOMEM;
+	}
+
+	intel_crtc->histogram = histogram;
+	histogram->crtc = intel_crtc;
+	histogram->can_enable = false;
+
+	return 0;
+}
diff --git a/drivers/gpu/drm/i915/display/intel_histogram.h b/drivers/gpu/drm/i915/display/intel_histogram.h
new file mode 100644
index 000000000000..9d66724f9c53
--- /dev/null
+++ b/drivers/gpu/drm/i915/display/intel_histogram.h
@@ -0,0 +1,35 @@
+// SPDX-License-Identifier: MIT
+/*
+ * Copyright © 2024 Intel Corporation
+ */
+
+#ifndef __INTEL_HISTOGRAM_H__
+#define __INTEL_HISTOGRAM_H__
+
+#include <linux/types.h>
+
+struct intel_crtc;
+
+#define HISTOGRAM_BIN_COUNT                    32
+#define HISTOGRAM_IET_LENGTH                   33
+
+enum intel_global_hist_status {
+	INTEL_HISTOGRAM_ENABLE,
+	INTEL_HISTOGRAM_DISABLE,
+};
+
+enum intel_global_histogram {
+	INTEL_HISTOGRAM,
+};
+
+enum intel_global_hist_lut {
+	INTEL_HISTOGRAM_PIXEL_FACTOR,
+};
+
+int intel_histogram_atomic_check(struct intel_crtc *intel_crtc);
+int intel_histogram_update(struct intel_crtc *intel_crtc, bool enable);
+int intel_histogram_set_iet_lut(struct intel_crtc *intel_crtc, u32 *data);
+int intel_histogram_init(struct intel_crtc *intel_crtc);
+void intel_histogram_finish(struct intel_crtc *intel_crtc);
+
+#endif /* __INTEL_HISTOGRAM_H__ */
-- 
2.25.1

RE: [PATCHv6 7/8] drm/i915/histogram: Histogram changes for Display 20+

[Murthy, Arun R]

> > -----Original Message-----
> > From: dri-devel <dri-devel-bounces@lists.freedesktop.org> On Behalf Of
> > Arun R Murthy
> > Sent: Thursday, November 21, 2024 5:56 PM
> > To: intel-xe@lists.freedesktop.org; intel-gfx@lists.freedesktop.org;
> > dri- devel@lists.freedesktop.org
> > Cc: Murthy, Arun R <arun.r.murthy@intel.com>
> > Subject: [PATCHv6 7/8] drm/i915/histogram: Histogram changes for
> > Display
> > 20+
> >
> > In Display 20+, new registers are added for setting index, reading
> > histogram and writing the IET.
> >
> > v2: Removed duplicate code (Jani)
> > v3: Moved histogram core changes to earlier patches (Jani/Suraj)
> > v4: Rebased after addressing comments on patch 1
> > v5: Added the retry logic from patch3 and rebased the patch series
> > v6: optimize wite_iet() (Suraj)
> 
> I think you missed some comments from previous revision Add the bspec
> reference for registers added
> 
Added

> >
> > Signed-off-by: Arun R Murthy <arun.r.murthy@intel.com>
> > ---
> >  .../gpu/drm/i915/display/intel_histogram.c    | 105 +++++++++++++-----
> >  .../drm/i915/display/intel_histogram_regs.h   |  25 +++++
> >  2 files changed, 103 insertions(+), 27 deletions(-)
> >
> > diff --git a/drivers/gpu/drm/i915/display/intel_histogram.c
> > b/drivers/gpu/drm/i915/display/intel_histogram.c
> > index a64e778fface..db4bc60be557 100644
> > --- a/drivers/gpu/drm/i915/display/intel_histogram.c
> > +++ b/drivers/gpu/drm/i915/display/intel_histogram.c
> > @@ -29,6 +29,37 @@ struct intel_histogram {
> >  	u32 bin_data[HISTOGRAM_BIN_COUNT];
> >  };
> >
> > +static void set_bin_index_0(struct intel_display *display, enum pipe
> > +pipe) {
> > +	if (DISPLAY_VER(display) >= 20)
> > +		intel_de_rmw(display, DPST_IE_INDEX(pipe),
> > +			     DPST_IE_BIN_INDEX_MASK,
> > DPST_IE_BIN_INDEX(0));
> > +	else
> > +		intel_de_rmw(display, DPST_CTL(pipe),
> > +			     DPST_CTL_BIN_REG_MASK,
> > +			     DPST_CTL_BIN_REG_CLEAR);
> > +}
> > +
> > +static void write_iet(struct intel_display *display, enum pipe pipe,
> > +			      u32 *data)
> > +{
> > +	int i;
> > +
> > +	for (i = 0; i < HISTOGRAM_IET_LENGTH; i++) {
> > +		if (DISPLAY_VER(display) >= 20)
> > +			intel_de_rmw(display, DPST_IE_BIN(pipe),
> > +				     DPST_IE_BIN_DATA_MASK,
> > +				     DPST_IE_BIN_DATA(data[i]));
> > +		else
> > +			intel_de_rmw(display, DPST_BIN(pipe),
> > +				     DPST_BIN_DATA_MASK,
> > +				     DPST_BIN_DATA(data[i]));
> > +
> > +		drm_dbg_atomic(display->drm, "iet_lut[%d]=%x\n",
> > +			       i, data[i]);
> > +	}
> 
> This looks more clean according to me
> if (DISPLAY_VER(display) >= 20) {
>     register_base = DPST_IE_BIN(pipe);
>     data_mask = DPST_IE_BIN_DATA_MASK;
>     data_temp = DPST_IE_BIN_DATA(data[i]); } else {
>     register_base = DPST_BIN(pipe);
>     data_mask = DPST_BIN_DATA_MASK;
>     data_temp = DPST_BIN_DATA(data[i]);
> }
>  intel_de_rmw(display, register_base, data_mask, data_temp);
>   drm_dbg_atomic(display->drm, "iet_lut[%d]=%x\n", i, data[i]);
> 

With the above code snippet data_temp will have to be in the for loop so as to get the bit mapped value of data[i]

Thanks and Regards,
Arun R Murthy
--------------------

[PATCHv3 6/8] drm/i915/histogram: histogram delay counter doesnt reset

[Arun R Murthy]

The delay counter for histogram does not reset and as a result the
histogram bin never gets updated. Workaround would be to use save and
restore histogram register.

v2: Follow the seq in interrupt handler
	Restore DPST bit 0
	read/write dpst ctl rg
	Restore DPST bit 1 and Guardband Delay Interrupt counter = 0
	(Suraj)
v3: updated wa version for display 13 and 14

Wa: 14014889975
Signed-off-by: Arun R Murthy <arun.r.murthy@intel.com>
---
 drivers/gpu/drm/i915/display/intel_histogram.c     | 14 ++++++++++++++
 .../gpu/drm/i915/display/intel_histogram_regs.h    |  2 ++
 2 files changed, 16 insertions(+)

diff --git a/drivers/gpu/drm/i915/display/intel_histogram.c b/drivers/gpu/drm/i915/display/intel_histogram.c
index add303df21d5..7b27c7227a8a 100644
--- a/drivers/gpu/drm/i915/display/intel_histogram.c
+++ b/drivers/gpu/drm/i915/display/intel_histogram.c
@@ -59,6 +59,11 @@ static void intel_histogram_handle_int_work(struct work_struct *work)
 	snprintf(pipe_id, sizeof(pipe_id),
 		 "PIPE=%u", intel_crtc->base.base.id);
 
+	/* Wa: 14014889975 */
+	if (IS_DISPLAY_VER(display, 13, 14))
+		intel_de_rmw(display, DPST_CTL(intel_crtc->pipe),
+			     DPST_CTL_RESTORE, 0);
+
 	/*
 	 * TODO: PSR to be exited while reading the Histogram data
 	 * Set DPST_CTL Bin Reg function select to TC
@@ -86,6 +91,15 @@ static void intel_histogram_handle_int_work(struct work_struct *work)
 		return;
 	}
 
+	/* Wa: 14014889975 */
+	if (IS_DISPLAY_VER(display, 13, 14))
+		/* Write the value read from DPST_CTL to DPST_CTL.Interrupt Delay Counter(bit 23:16) */
+		intel_de_rmw(display, DPST_CTL(intel_crtc->pipe),
+			     DPST_CTL_GUARDBAND_INTERRUPT_DELAY_CNT |
+			     DPST_CTL_RESTORE,
+			     DPST_CTL_GUARDBAND_INTERRUPT_DELAY(0x0) |
+			     DPST_CTL_RESTORE);
+
 	/* Enable histogram interrupt */
 	intel_de_rmw(display, DPST_GUARD(intel_crtc->pipe), DPST_GUARD_HIST_INT_EN,
 		     DPST_GUARD_HIST_INT_EN);
diff --git a/drivers/gpu/drm/i915/display/intel_histogram_regs.h b/drivers/gpu/drm/i915/display/intel_histogram_regs.h
index 1252b4f339a6..213c9f483567 100644
--- a/drivers/gpu/drm/i915/display/intel_histogram_regs.h
+++ b/drivers/gpu/drm/i915/display/intel_histogram_regs.h
@@ -16,6 +16,8 @@
 #define  DPST_CTL_RESTORE				REG_BIT(28)
 #define  DPST_CTL_IE_MODI_TABLE_EN			REG_BIT(27)
 #define  DPST_CTL_HIST_MODE				REG_BIT(24)
+#define  DPST_CTL_GUARDBAND_INTERRUPT_DELAY_CNT		REG_GENMASK(23, 16)
+#define  DPST_CTL_GUARDBAND_INTERRUPT_DELAY(val)	REG_FIELD_PREP(DPST_CTL_GUARDBAND_INTERRUPT_DELAY_CNT, val)
 #define  DPST_CTL_ENHANCEMENT_MODE_MASK			REG_GENMASK(14, 13)
 #define  DPST_CTL_EN_MULTIPLICATIVE			REG_FIELD_PREP(DPST_CTL_ENHANCEMENT_MODE_MASK, 2)
 #define  DPST_CTL_IE_TABLE_VALUE_FORMAT			REG_BIT(15)
-- 
2.25.1

[PATCHv6 7/8] drm/i915/histogram: Histogram changes for Display 20+

[Arun R Murthy]

In Display 20+, new registers are added for setting index, reading
histogram and writing the IET.

v2: Removed duplicate code (Jani)
v3: Moved histogram core changes to earlier patches (Jani/Suraj)
v4: Rebased after addressing comments on patch 1
v5: Added the retry logic from patch3 and rebased the patch series
v6: optimize wite_iet() (Suraj)

Bspec: 68895
Signed-off-by: Arun R Murthy <arun.r.murthy@intel.com>
---
 .../gpu/drm/i915/display/intel_histogram.c    | 105 +++++++++++++-----
 .../drm/i915/display/intel_histogram_regs.h   |  25 +++++
 2 files changed, 103 insertions(+), 27 deletions(-)

diff --git a/drivers/gpu/drm/i915/display/intel_histogram.c b/drivers/gpu/drm/i915/display/intel_histogram.c
index 7b27c7227a8a..475d29441612 100644
--- a/drivers/gpu/drm/i915/display/intel_histogram.c
+++ b/drivers/gpu/drm/i915/display/intel_histogram.c
@@ -29,6 +29,37 @@ struct intel_histogram {
 	u32 bin_data[HISTOGRAM_BIN_COUNT];
 };
 
+static void set_bin_index_0(struct intel_display *display, enum pipe pipe)
+{
+	if (DISPLAY_VER(display) >= 20)
+		intel_de_rmw(display, DPST_IE_INDEX(pipe),
+			     DPST_IE_BIN_INDEX_MASK, DPST_IE_BIN_INDEX(0));
+	else
+		intel_de_rmw(display, DPST_CTL(pipe),
+			     DPST_CTL_BIN_REG_MASK,
+			     DPST_CTL_BIN_REG_CLEAR);
+}
+
+static void write_iet(struct intel_display *display, enum pipe pipe,
+			      u32 *data)
+{
+	int i;
+
+	for (i = 0; i < HISTOGRAM_IET_LENGTH; i++) {
+		if (DISPLAY_VER(display) >= 20)
+			intel_de_rmw(display, DPST_IE_BIN(pipe),
+				     DPST_IE_BIN_DATA_MASK,
+				     DPST_IE_BIN_DATA(data[i]));
+		else
+			intel_de_rmw(display, DPST_BIN(pipe),
+				     DPST_BIN_DATA_MASK,
+				     DPST_BIN_DATA(data[i]));
+
+		drm_dbg_atomic(display->drm, "iet_lut[%d]=%x\n",
+			       i, data[i]);
+	}
+}
+
 static bool intel_histogram_get_data(struct intel_crtc *intel_crtc)
 {
 	struct intel_display *display = to_intel_display(intel_crtc);
@@ -36,12 +67,27 @@ static bool intel_histogram_get_data(struct intel_crtc *intel_crtc)
 	int index;
 	u32 dpstbin;
 
+	if (DISPLAY_VER(display) >= 20)
+		intel_de_rmw(display, DPST_HIST_INDEX(intel_crtc->pipe),
+			     DPST_HIST_BIN_INDEX_MASK,
+			     DPST_HIST_BIN_INDEX(0));
+	else
+		intel_de_rmw(display, DPST_CTL(intel_crtc->pipe),
+			     DPST_CTL_BIN_REG_FUNC_SEL | DPST_CTL_BIN_REG_MASK, 0);
+
 	for (index = 0; index < ARRAY_SIZE(histogram->bin_data); index++) {
-		dpstbin = intel_de_read(display, DPST_BIN(intel_crtc->pipe));
+		dpstbin = intel_de_read(display, (DISPLAY_VER(display) >= 20 ?
+					DPST_HIST_BIN(intel_crtc->pipe) :
+					DPST_BIN(intel_crtc->pipe)));
 		if (!(dpstbin & DPST_BIN_BUSY)) {
-			histogram->bin_data[index] = dpstbin & DPST_BIN_DATA_MASK;
-		} else
+			histogram->bin_data[index] = dpstbin & (DISPLAY_VER(display) >= 20 ?
+								DPST_HIST_BIN_DATA_MASK :
+								DPST_BIN_DATA_MASK);
+		} else {
+			drm_err(display->drm, "Histogram bin busy, retyring\n");
+			fsleep(2);
 			return false;
+		}
 	}
 	return true;
 }
@@ -69,8 +115,6 @@ static void intel_histogram_handle_int_work(struct work_struct *work)
 	 * Set DPST_CTL Bin Reg function select to TC
 	 * Set DPST_CTL Bin Register Index to 0
 	 */
-	intel_de_rmw(display, DPST_CTL(intel_crtc->pipe),
-		     DPST_CTL_BIN_REG_FUNC_SEL | DPST_CTL_BIN_REG_MASK, 0);
 	for (retry = 0; retry < HISTOGRAM_BIN_READ_RETRY_COUNT; retry++) {
 		if (intel_histogram_get_data(intel_crtc)) {
 			drm_property_replace_global_blob(display->drm,
@@ -150,15 +194,26 @@ static int intel_histogram_enable(struct intel_crtc *intel_crtc)
 	if (histogram->enable)
 		return 0;
 
-	 /* enable histogram, clear DPST_CTL bin reg func select to TC */
-	intel_de_rmw(display, DPST_CTL(pipe),
-		     DPST_CTL_BIN_REG_FUNC_SEL | DPST_CTL_IE_HIST_EN |
-		     DPST_CTL_HIST_MODE | DPST_CTL_IE_TABLE_VALUE_FORMAT |
-		     DPST_CTL_ENHANCEMENT_MODE_MASK | DPST_CTL_IE_MODI_TABLE_EN,
-		     DPST_CTL_BIN_REG_FUNC_TC | DPST_CTL_IE_HIST_EN |
-		     DPST_CTL_HIST_MODE_HSV |
-		     DPST_CTL_IE_TABLE_VALUE_FORMAT_1INT_9FRAC |
-		     DPST_CTL_EN_MULTIPLICATIVE | DPST_CTL_IE_MODI_TABLE_EN);
+	 /* enable histogram, clear DPST_BIN reg and select TC function */
+	if (DISPLAY_VER(display) >= 20)
+		intel_de_rmw(display, DPST_CTL(pipe),
+			     DPST_CTL_IE_HIST_EN |
+			     DPST_CTL_HIST_MODE,
+			     DPST_CTL_IE_HIST_EN |
+			     DPST_CTL_HIST_MODE_HSV);
+	else
+		 /* enable histogram, clear DPST_BIN reg and select TC function */
+		intel_de_rmw(display, DPST_CTL(pipe),
+			     DPST_CTL_BIN_REG_FUNC_SEL | DPST_CTL_IE_HIST_EN |
+			     DPST_CTL_HIST_MODE |
+			     DPST_CTL_IE_TABLE_VALUE_FORMAT |
+			     DPST_CTL_ENHANCEMENT_MODE_MASK |
+			     DPST_CTL_IE_MODI_TABLE_EN,
+			     DPST_CTL_BIN_REG_FUNC_TC | DPST_CTL_IE_HIST_EN |
+			     DPST_CTL_HIST_MODE_HSV |
+			     DPST_CTL_IE_TABLE_VALUE_FORMAT_1INT_9FRAC |
+			     DPST_CTL_EN_MULTIPLICATIVE |
+			     DPST_CTL_IE_MODI_TABLE_EN);
 
 	/* Re-Visit: check if wait for one vblank is required */
 	drm_crtc_wait_one_vblank(&intel_crtc->base);
@@ -227,7 +282,6 @@ int intel_histogram_set_iet_lut(struct intel_crtc *intel_crtc, u32 *data)
 	struct intel_histogram *histogram = intel_crtc->histogram;
 	struct intel_display *display = to_intel_display(intel_crtc);
 	int pipe = intel_crtc->pipe;
-	int i = 0;
 
 	if (!histogram)
 		return -EINVAL;
@@ -242,22 +296,19 @@ int intel_histogram_set_iet_lut(struct intel_crtc *intel_crtc, u32 *data)
 		return -EINVAL;
 	}
 
-	/* Set DPST_CTL Bin Reg function select to IE & wait for a vblabk */
-	intel_de_rmw(display, DPST_CTL(pipe),
-		     DPST_CTL_BIN_REG_FUNC_SEL, DPST_CTL_BIN_REG_FUNC_IE);
 
-	drm_crtc_wait_one_vblank(&intel_crtc->base);
+	if (DISPLAY_VER(display) < 20) {
+		/* Set DPST_CTL Bin Reg function select to IE & wait for a vblabk */
+		intel_de_rmw(display, DPST_CTL(pipe),
+			     DPST_CTL_BIN_REG_FUNC_SEL,
+			     DPST_CTL_BIN_REG_FUNC_IE);
 
-	 /* Set DPST_CTL Bin Register Index to 0 */
-	intel_de_rmw(display, DPST_CTL(pipe),
-		     DPST_CTL_BIN_REG_MASK, DPST_CTL_BIN_REG_CLEAR);
-
-	for (i = 0; i < HISTOGRAM_IET_LENGTH; i++) {
-		intel_de_rmw(display, DPST_BIN(pipe),
-			     DPST_BIN_DATA_MASK, data[i]);
-		drm_dbg_atomic(display->drm, "iet_lut[%d]=%x\n", i, data[i]);
+		drm_crtc_wait_one_vblank(&intel_crtc->base);
 	}
 
+	set_bin_index_0(display, pipe);
+	write_iet(display, pipe, data);
+
 	return 0;
 }
 
diff --git a/drivers/gpu/drm/i915/display/intel_histogram_regs.h b/drivers/gpu/drm/i915/display/intel_histogram_regs.h
index 213c9f483567..3fbb9c2deaae 100644
--- a/drivers/gpu/drm/i915/display/intel_histogram_regs.h
+++ b/drivers/gpu/drm/i915/display/intel_histogram_regs.h
@@ -45,6 +45,31 @@
 #define _DPST_BIN_B					0x491C4
 #define DPST_BIN(pipe)					_MMIO_PIPE(pipe, _DPST_BIN_A, _DPST_BIN_B)
 #define  DPST_BIN_DATA_MASK				REG_GENMASK(23, 0)
+#define  DPST_BIN_DATA(val)				REG_FIELD_PREP(DPST_BIN_DATA_MASK, val)
 #define  DPST_BIN_BUSY					REG_BIT(31)
 
+#define _DPST_HIST_INDEX_A				0x490D8
+#define _DPST_HIST_INDEX_B				0x491D8
+#define DPST_HIST_INDEX(pipe)				_MMIO_PIPE(pipe, _DPST_HIST_INDEX_A, _DPST_HIST_INDEX_B)
+#define  DPST_HIST_BIN_INDEX_MASK			REG_GENMASK(4, 0)
+#define  DPST_HIST_BIN_INDEX(val)			REG_FIELD_PREP(DPST_HIST_BIN_INDEX_MASK, val)
+
+#define _DPST_HIST_BIN_A				0x490C4
+#define _DPST_HIST_BIN_B				0x491C4
+#define DPST_HIST_BIN(pipe)				_MMIO_PIPE(pipe, _DPST_HIST_BIN_A, _DPST_HIST_BIN_B)
+#define  DPST_HIST_BIN_BUSY				REG_BIT(31)
+#define  DPST_HIST_BIN_DATA_MASK				REG_GENMASK(30, 0)
+
+#define _DPST_IE_BIN_A					0x490CC
+#define _DPST_IE_BIN_B					0x491CC
+#define DPST_IE_BIN(pipe)				_MMIO_PIPE(pipe, _DPST_IE_BIN_A, _DPST_IE_BIN_B)
+#define	 DPST_IE_BIN_DATA_MASK				REG_GENMASK(9, 0)
+#define  DPST_IE_BIN_DATA(val)				REG_FIELD_PREP(DPST_IE_BIN_DATA_MASK, val)
+
+#define _DPST_IE_INDEX_A				0x490DC
+#define _DPST_IE_INDEX_B				0x491DC
+#define DPST_IE_INDEX(pipe)				_MMIO_PIPE(pipe, _DPST_IE_INDEX_A, _DPST_IE_INDEX_B)
+#define  DPST_IE_BIN_INDEX_MASK				REG_GENMASK(6, 0)
+#define  DPST_IE_BIN_INDEX(val)				REG_FIELD_PREP(DPST_IE_BIN_INDEX_MASK, val)
+
 #endif /* __INTEL_HISTOGRAM_REGS_H__ */
-- 
2.25.1

RE: [PATCHv6 7/8] drm/i915/histogram: Histogram changes for Display 20+

[Kandpal, Suraj]

> -----Original Message-----
> From: Murthy, Arun R <arun.r.murthy@intel.com>
> Sent: Thursday, November 21, 2024 8:10 PM
> To: Kandpal, Suraj <suraj.kandpal@intel.com>; intel-xe@lists.freedesktop.org;
> intel-gfx@lists.freedesktop.org; dri-devel@lists.freedesktop.org
> Subject: RE: [PATCHv6 7/8] drm/i915/histogram: Histogram changes for
> Display 20+
> 
> > > -----Original Message-----
> > > From: dri-devel <dri-devel-bounces@lists.freedesktop.org> On Behalf
> > > Of Arun R Murthy
> > > Sent: Thursday, November 21, 2024 5:56 PM
> > > To: intel-xe@lists.freedesktop.org; intel-gfx@lists.freedesktop.org;
> > > dri- devel@lists.freedesktop.org
> > > Cc: Murthy, Arun R <arun.r.murthy@intel.com>
> > > Subject: [PATCHv6 7/8] drm/i915/histogram: Histogram changes for
> > > Display
> > > 20+
> > >
> > > In Display 20+, new registers are added for setting index, reading
> > > histogram and writing the IET.
> > >
> > > v2: Removed duplicate code (Jani)
> > > v3: Moved histogram core changes to earlier patches (Jani/Suraj)
> > > v4: Rebased after addressing comments on patch 1
> > > v5: Added the retry logic from patch3 and rebased the patch series
> > > v6: optimize wite_iet() (Suraj)
> >
> > I think you missed some comments from previous revision Add the bspec
> > reference for registers added
> >
> Added
> 
> > >
> > > Signed-off-by: Arun R Murthy <arun.r.murthy@intel.com>
> > > ---
> > >  .../gpu/drm/i915/display/intel_histogram.c    | 105 +++++++++++++-----
> > >  .../drm/i915/display/intel_histogram_regs.h   |  25 +++++
> > >  2 files changed, 103 insertions(+), 27 deletions(-)
> > >
> > > diff --git a/drivers/gpu/drm/i915/display/intel_histogram.c
> > > b/drivers/gpu/drm/i915/display/intel_histogram.c
> > > index a64e778fface..db4bc60be557 100644
> > > --- a/drivers/gpu/drm/i915/display/intel_histogram.c
> > > +++ b/drivers/gpu/drm/i915/display/intel_histogram.c
> > > @@ -29,6 +29,37 @@ struct intel_histogram {
> > >  	u32 bin_data[HISTOGRAM_BIN_COUNT];  };
> > >
> > > +static void set_bin_index_0(struct intel_display *display, enum
> > > +pipe
> > > +pipe) {
> > > +	if (DISPLAY_VER(display) >= 20)
> > > +		intel_de_rmw(display, DPST_IE_INDEX(pipe),
> > > +			     DPST_IE_BIN_INDEX_MASK,
> > > DPST_IE_BIN_INDEX(0));
> > > +	else
> > > +		intel_de_rmw(display, DPST_CTL(pipe),
> > > +			     DPST_CTL_BIN_REG_MASK,
> > > +			     DPST_CTL_BIN_REG_CLEAR);
> > > +}
> > > +
> > > +static void write_iet(struct intel_display *display, enum pipe pipe,
> > > +			      u32 *data)
> > > +{
> > > +	int i;
> > > +
> > > +	for (i = 0; i < HISTOGRAM_IET_LENGTH; i++) {
> > > +		if (DISPLAY_VER(display) >= 20)
> > > +			intel_de_rmw(display, DPST_IE_BIN(pipe),
> > > +				     DPST_IE_BIN_DATA_MASK,
> > > +				     DPST_IE_BIN_DATA(data[i]));
> > > +		else
> > > +			intel_de_rmw(display, DPST_BIN(pipe),
> > > +				     DPST_BIN_DATA_MASK,
> > > +				     DPST_BIN_DATA(data[i]));
> > > +
> > > +		drm_dbg_atomic(display->drm, "iet_lut[%d]=%x\n",
> > > +			       i, data[i]);
> > > +	}
> >
> > This looks more clean according to me
> > if (DISPLAY_VER(display) >= 20) {
> >     register_base = DPST_IE_BIN(pipe);
> >     data_mask = DPST_IE_BIN_DATA_MASK;
> >     data_temp = DPST_IE_BIN_DATA(data[i]); } else {
> >     register_base = DPST_BIN(pipe);
> >     data_mask = DPST_BIN_DATA_MASK;
> >     data_temp = DPST_BIN_DATA(data[i]); }  intel_de_rmw(display,
> > register_base, data_mask, data_temp);
> >   drm_dbg_atomic(display->drm, "iet_lut[%d]=%x\n", i, data[i]);
> >
> 
> With the above code snippet data_temp will have to be in the for loop so as
> to get the bit mapped value of data[i]
> 

Yes the  whole code snippet will be inside the loop itself

Regards,
Suraj Kandpal

> Thanks and Regards,
> Arun R Murthy
> --------------------

RE: [PATCHv6 7/8] drm/i915/histogram: Histogram changes for Display 20+

[Murthy, Arun R]

> > > > +static void write_iet(struct intel_display *display, enum pipe pipe,
> > > > +			      u32 *data)
> > > > +{
> > > > +	int i;
> > > > +
> > > > +	for (i = 0; i < HISTOGRAM_IET_LENGTH; i++) {
> > > > +		if (DISPLAY_VER(display) >= 20)
> > > > +			intel_de_rmw(display, DPST_IE_BIN(pipe),
> > > > +				     DPST_IE_BIN_DATA_MASK,
> > > > +				     DPST_IE_BIN_DATA(data[i]));
> > > > +		else
> > > > +			intel_de_rmw(display, DPST_BIN(pipe),
> > > > +				     DPST_BIN_DATA_MASK,
> > > > +				     DPST_BIN_DATA(data[i]));
> > > > +
> > > > +		drm_dbg_atomic(display->drm, "iet_lut[%d]=%x\n",
> > > > +			       i, data[i]);
> > > > +	}
> > >
> > > This looks more clean according to me if (DISPLAY_VER(display) >=
> > > 20) {
> > >     register_base = DPST_IE_BIN(pipe);
> > >     data_mask = DPST_IE_BIN_DATA_MASK;
> > >     data_temp = DPST_IE_BIN_DATA(data[i]); } else {
> > >     register_base = DPST_BIN(pipe);
> > >     data_mask = DPST_BIN_DATA_MASK;
> > >     data_temp = DPST_BIN_DATA(data[i]); }  intel_de_rmw(display,
> > > register_base, data_mask, data_temp);
> > >   drm_dbg_atomic(display->drm, "iet_lut[%d]=%x\n", i, data[i]);
> > >
> >
> > With the above code snippet data_temp will have to be in the for loop
> > so as to get the bit mapped value of data[i]
> >
> 
> Yes the  whole code snippet will be inside the loop itself
> 
In that case I don't see any advantage of this over the present code.
If you still insist will do the necessary changes.

Thanks and Regards,
Arun R Murthy
--------------------

RE: [PATCHv6 7/8] drm/i915/histogram: Histogram changes for Display 20+

[Kandpal, Suraj]

> -----Original Message-----
> From: Murthy, Arun R <arun.r.murthy@intel.com>
> Sent: Friday, November 22, 2024 1:49 PM
> To: Kandpal, Suraj <suraj.kandpal@intel.com>; intel-xe@lists.freedesktop.org;
> intel-gfx@lists.freedesktop.org; dri-devel@lists.freedesktop.org
> Subject: RE: [PATCHv6 7/8] drm/i915/histogram: Histogram changes for
> Display 20+
> 
> > > > > +static void write_iet(struct intel_display *display, enum pipe pipe,
> > > > > +			      u32 *data)
> > > > > +{
> > > > > +	int i;
> > > > > +
> > > > > +	for (i = 0; i < HISTOGRAM_IET_LENGTH; i++) {
> > > > > +		if (DISPLAY_VER(display) >= 20)
> > > > > +			intel_de_rmw(display, DPST_IE_BIN(pipe),
> > > > > +				     DPST_IE_BIN_DATA_MASK,
> > > > > +				     DPST_IE_BIN_DATA(data[i]));
> > > > > +		else
> > > > > +			intel_de_rmw(display, DPST_BIN(pipe),
> > > > > +				     DPST_BIN_DATA_MASK,
> > > > > +				     DPST_BIN_DATA(data[i]));
> > > > > +
> > > > > +		drm_dbg_atomic(display->drm, "iet_lut[%d]=%x\n",
> > > > > +			       i, data[i]);
> > > > > +	}
> > > >
> > > > This looks more clean according to me if (DISPLAY_VER(display) >=
> > > > 20) {
> > > >     register_base = DPST_IE_BIN(pipe);
> > > >     data_mask = DPST_IE_BIN_DATA_MASK;
> > > >     data_temp = DPST_IE_BIN_DATA(data[i]); } else {
> > > >     register_base = DPST_BIN(pipe);
> > > >     data_mask = DPST_BIN_DATA_MASK;
> > > >     data_temp = DPST_BIN_DATA(data[i]); }  intel_de_rmw(display,
> > > > register_base, data_mask, data_temp);
> > > >   drm_dbg_atomic(display->drm, "iet_lut[%d]=%x\n", i, data[i]);
> > > >
> > >
> > > With the above code snippet data_temp will have to be in the for
> > > loop so as to get the bit mapped value of data[i]
> > >
> >
> > Yes the  whole code snippet will be inside the loop itself
> >
> In that case I don't see any advantage of this over the present code.
> If you still insist will do the necessary changes.

I think it looks much cleaner and the variables also help explain what the values are instead
Of just craming a bunch of macros in two differenct intel_de_rmw
Side note make data_temp into bin_data or something around those lines

Regards,
Suraj Kandpal

> 
> Thanks and Regards,
> Arun R Murthy
> --------------------