[v3,2/3] drm/i915/color: Extract icl_read_luts()
diff mbox series

Message ID 1568917040-3365-3-git-send-email-swati2.sharma@intel.com
State New
Headers show
Series
  • adding gamma state checker for icl+ platforms
Related show

Commit Message

Swati Sharma Sept. 19, 2019, 6:17 p.m. UTC
For icl+, have hw read out to create hw blob of gamma
lut values. icl+ platforms supports multi segmented gamma
mode by default, add hw lut creation for this mode.

This will be used to validate gamma programming using dsb
(display state buffer) which is a tgl specific feature.

Following are the main changes done in this patch:
1. gamma_enable checks made specific to platform func()
   since icl doeesn't support that and enable gamma through mode
2. lut[0] and lut[8] enteries should be same superfine and coarse;
   superfine and fine segments respectively, checked twice-no harm
3. Removed temporary lut
4. Coarse segment interpolated gamma values loop start from 2
   instead of 0, since actual h/w values started getting overrided.

v2: -readout code for multisegmented gamma has to come
     up with some intermediate entries that aren't preserved
     in hardware (Jani N)
    -linear interpolation (Ville)
    -moved common code to check gamma_enable to specific funcs,
     since icl doesn't support that
v3: -use u16 instead of __u16 [Jani N]
    -used single lut [Jani N]
    -improved and more readable for loops [Jani N]
    -read values directly to actual locations and then fill gaps [Jani N]
    -moved cleaning to patch 1 [Jani N]
    -renamed icl_read_lut_multi_seg() to icl_read_lut_multi_segment to
     make it similar to icl_load_luts()
    -renamed icl_compute_interpolated_gamma_blob() to
     icl_compute_interpolated_gamma_lut_values() more sensible, I guess

Signed-off-by: Swati Sharma <swati2.sharma@intel.com>
---
 drivers/gpu/drm/i915/display/intel_color.c | 216 +++++++++++++++++++++++++++--
 drivers/gpu/drm/i915/i915_reg.h            |   7 +
 2 files changed, 208 insertions(+), 15 deletions(-)

Comments

Jani Nikula Sept. 20, 2019, 10:24 a.m. UTC | #1
On Thu, 19 Sep 2019, Swati Sharma <swati2.sharma@intel.com> wrote:
> For icl+, have hw read out to create hw blob of gamma
> lut values. icl+ platforms supports multi segmented gamma
> mode by default, add hw lut creation for this mode.
>
> This will be used to validate gamma programming using dsb
> (display state buffer) which is a tgl specific feature.
>
> Following are the main changes done in this patch:
> 1. gamma_enable checks made specific to platform func()
>    since icl doeesn't support that and enable gamma through mode
> 2. lut[0] and lut[8] enteries should be same superfine and coarse;
>    superfine and fine segments respectively, checked twice-no harm
> 3. Removed temporary lut
> 4. Coarse segment interpolated gamma values loop start from 2
>    instead of 0, since actual h/w values started getting overrided.
>
> v2: -readout code for multisegmented gamma has to come
>      up with some intermediate entries that aren't preserved
>      in hardware (Jani N)
>     -linear interpolation (Ville)
>     -moved common code to check gamma_enable to specific funcs,
>      since icl doesn't support that
> v3: -use u16 instead of __u16 [Jani N]
>     -used single lut [Jani N]
>     -improved and more readable for loops [Jani N]
>     -read values directly to actual locations and then fill gaps [Jani N]
>     -moved cleaning to patch 1 [Jani N]
>     -renamed icl_read_lut_multi_seg() to icl_read_lut_multi_segment to
>      make it similar to icl_load_luts()
>     -renamed icl_compute_interpolated_gamma_blob() to
>      icl_compute_interpolated_gamma_lut_values() more sensible, I guess
>
> Signed-off-by: Swati Sharma <swati2.sharma@intel.com>
> ---
>  drivers/gpu/drm/i915/display/intel_color.c | 216 +++++++++++++++++++++++++++--
>  drivers/gpu/drm/i915/i915_reg.h            |   7 +
>  2 files changed, 208 insertions(+), 15 deletions(-)
>
> diff --git a/drivers/gpu/drm/i915/display/intel_color.c b/drivers/gpu/drm/i915/display/intel_color.c
> index 765482d..ad548ce 100644
> --- a/drivers/gpu/drm/i915/display/intel_color.c
> +++ b/drivers/gpu/drm/i915/display/intel_color.c
> @@ -1371,6 +1371,9 @@ static int icl_color_check(struct intel_crtc_state *crtc_state)
>  
>  static int i9xx_gamma_precision(const struct intel_crtc_state *crtc_state)
>  {
> +	if (!crtc_state->gamma_enable)
> +		return 0;
> +
>  	switch (crtc_state->gamma_mode) {
>  	case GAMMA_MODE_MODE_8BIT:
>  		return 8;
> @@ -1384,6 +1387,9 @@ static int i9xx_gamma_precision(const struct intel_crtc_state *crtc_state)
>  
>  static int ilk_gamma_precision(const struct intel_crtc_state *crtc_state)
>  {
> +	if (!crtc_state->gamma_enable)
> +		return 0;
> +
>  	if ((crtc_state->csc_mode & CSC_POSITION_BEFORE_GAMMA) == 0)
>  		return 0;
>  
> @@ -1400,6 +1406,9 @@ static int ilk_gamma_precision(const struct intel_crtc_state *crtc_state)
>  
>  static int chv_gamma_precision(const struct intel_crtc_state *crtc_state)
>  {
> +	if (!crtc_state->gamma_enable)
> +		return 0;
> +
>  	if (crtc_state->cgm_mode & CGM_PIPE_MODE_GAMMA)
>  		return 10;
>  	else
> @@ -1408,6 +1417,9 @@ static int chv_gamma_precision(const struct intel_crtc_state *crtc_state)
>  
>  static int glk_gamma_precision(const struct intel_crtc_state *crtc_state)
>  {
> +	if (!crtc_state->gamma_enable)
> +		return 0;
> +
>  	switch (crtc_state->gamma_mode) {
>  	case GAMMA_MODE_MODE_8BIT:
>  		return 8;
> @@ -1419,21 +1431,39 @@ static int glk_gamma_precision(const struct intel_crtc_state *crtc_state)
>  	}
>  }
>  
> +static int icl_gamma_precision(const struct intel_crtc_state *crtc_state)
> +{
> +	if ((crtc_state->gamma_mode & POST_CSC_GAMMA_ENABLE) == 0)
> +		return 0;
> +
> +	switch (crtc_state->gamma_mode & GAMMA_MODE_MODE_MASK) {
> +	case GAMMA_MODE_MODE_8BIT:
> +		return 8;
> +	case GAMMA_MODE_MODE_10BIT:
> +		return 10;
> +	case GAMMA_MODE_MODE_12BIT_MULTI_SEGMENTED:
> +		return 16;
> +	default:
> +		MISSING_CASE(crtc_state->gamma_mode);
> +		return 0;
> +	}
> +
> +}
> +
>  int intel_color_get_gamma_bit_precision(const struct intel_crtc_state *crtc_state)
>  {
>  	struct intel_crtc *crtc = to_intel_crtc(crtc_state->base.crtc);
>  	struct drm_i915_private *dev_priv = to_i915(crtc->base.dev);
>  
> -	if (!crtc_state->gamma_enable)
> -		return 0;
> -
>  	if (HAS_GMCH(dev_priv)) {
>  		if (IS_CHERRYVIEW(dev_priv))
>  			return chv_gamma_precision(crtc_state);
>  		else
>  			return i9xx_gamma_precision(crtc_state);
>  	} else {
> -		if (IS_CANNONLAKE(dev_priv) || IS_GEMINILAKE(dev_priv))
> +		if (INTEL_GEN(dev_priv) >= 11)
> +			return icl_gamma_precision(crtc_state);
> +		else if (IS_CANNONLAKE(dev_priv) || IS_GEMINILAKE(dev_priv))
>  			return glk_gamma_precision(crtc_state);
>  		else if (IS_IRONLAKE(dev_priv))
>  			return ilk_gamma_precision(crtc_state);
> @@ -1464,6 +1494,30 @@ static bool intel_color_lut_entry_equal(struct drm_color_lut *lut1,
>  	return true;
>  }
>  
> +static bool intel_color_lut_entry_multi_equal(struct drm_color_lut *lut1,
> +					      struct drm_color_lut *lut2,
> +					      int lut_size, u32 err)
> +{
> +	int i;
> +
> +	for (i = 0; i < 9; i++) {
> +		if (!err_check(&lut1[i], &lut2[i], err))
> +			return false;
> +	}
> +
> +	for (i = 1; i < 257; i++) {
> +		if (!err_check(&lut1[i * 8], &lut2[i * 8], err))
> +			return false;
> +	}
> +
> +	for (i = 0; i < 256; i++) {
> +		if (!err_check(&lut1[i * 8 * 128], &lut2[i * 8 * 128], err))
> +			return false;
> +	}

So apparently we're facing some issues with the readout of the relevant
registers. I suggest we wrap the above two loops in

#if 0


#endif

with a comment explaining why.

I don't much like this, but having *some* validation of this is better
than *no* validation.

BR,
Jani.


> +
> +	return true;
> +}
> +
>  bool intel_color_lut_equal(struct drm_property_blob *blob1,
>  			   struct drm_property_blob *blob2,
>  			   u32 gamma_mode, u32 bit_precision)
> @@ -1482,16 +1536,8 @@ bool intel_color_lut_equal(struct drm_property_blob *blob1,
>  	lut_size2 = drm_color_lut_size(blob2);
>  
>  	/* check sw and hw lut size */
> -	switch (gamma_mode) {
> -	case GAMMA_MODE_MODE_8BIT:
> -	case GAMMA_MODE_MODE_10BIT:
> -		if (lut_size1 != lut_size2)
> -			return false;
> -		break;
> -	default:
> -		MISSING_CASE(gamma_mode);
> -			return false;
> -	}
> +	if (lut_size1 != lut_size2)
> +		return false;
>  
>  	lut1 = blob1->data;
>  	lut2 = blob2->data;
> @@ -1499,13 +1545,18 @@ bool intel_color_lut_equal(struct drm_property_blob *blob1,
>  	err = 0xffff >> bit_precision;
>  
>  	/* check sw and hw lut entry to be equal */
> -	switch (gamma_mode) {
> +	switch (gamma_mode & GAMMA_MODE_MODE_MASK) {
>  	case GAMMA_MODE_MODE_8BIT:
>  	case GAMMA_MODE_MODE_10BIT:
>  		if (!intel_color_lut_entry_equal(lut1, lut2,
>  						 lut_size2, err))
>  			return false;
>  		break;
> +	case GAMMA_MODE_MODE_12BIT_MULTI_SEGMENTED:
> +		if (!intel_color_lut_entry_multi_equal(lut1, lut2,
> +						       lut_size2, err))
> +			return false;
> +		break;
>  	default:
>  		MISSING_CASE(gamma_mode);
>  			return false;
> @@ -1745,6 +1796,140 @@ static void glk_read_luts(struct intel_crtc_state *crtc_state)
>  		crtc_state->base.gamma_lut = glk_read_lut_10(crtc_state, PAL_PREC_INDEX_VALUE(0));
>  }
>  
> +static u16 cal_step_size(u16 end_val, u16 start_val, int steps)
> +{
> +	return ((end_val - start_val) / steps);
> +}
> +
> +static struct drm_color_lut *
> +icl_compute_interpolated_gamma_lut_values(struct drm_color_lut *lut, u32 lut_size)
> +{
> +	u16 red_step_size, green_step_size, blue_step_size;
> +	int start, end, steps;
> +	int i, j;
> +
> +	for (i = 1; i < 257 - 1; i++) {
> +		start = i * 8;
> +		end = (i + 1) * 8;
> +		steps = end - start;
> +
> +		red_step_size = cal_step_size(lut[end].red, lut[start].red, steps);
> +		green_step_size = cal_step_size(lut[end].green, lut[start].green, steps);
> +		blue_step_size = cal_step_size(lut[end].blue, lut[start].blue, steps);
> +
> +		for (j = start + 1; j < end; j++) {
> +			lut[j].red = lut[j - 1].red + red_step_size;
> +			lut[j].green = lut[j - 1].green + green_step_size;
> +			lut[j].blue = lut[j - 1].blue + blue_step_size;
> +
> +			i++;
> +		}
> +	}
> +
> +	for (i = 2; i < 256 - 1; i++) {
> +		start = i * 8 * 128;
> +		end = (i + 1) * 8 * 128;
> +		steps = end - start;
> +
> +		red_step_size = cal_step_size(lut[end].red, lut[start].red, steps);
> +		green_step_size = cal_step_size(lut[end].green, lut[start].green, steps);
> +		blue_step_size = cal_step_size(lut[end].blue, lut[start].blue, steps);
> +
> +		for (j = start + 1; j < end; j++) {
> +			lut[j].red = lut[j - 1].red + red_step_size;
> +			lut[j].green = lut[j - 1].green + green_step_size;
> +			lut[j].blue = lut[j - 1].blue + blue_step_size;
> +
> +			i++;
> +		}
> +	}
> +
> +	return lut;
> +}
> +
> +static struct drm_property_blob *
> +icl_read_lut_multi_segment(const struct intel_crtc_state *crtc_state)
> +{
> +	struct intel_crtc *crtc = to_intel_crtc(crtc_state->base.crtc);
> +	struct drm_i915_private *dev_priv = to_i915(crtc->base.dev);
> +	int lut_size = INTEL_INFO(dev_priv)->color.gamma_lut_size;
> +	enum pipe pipe = crtc->pipe;
> +	struct drm_property_blob *blob;
> +	struct drm_color_lut *blob_data;
> +	u32 i, val1, val2;
> +
> +	blob = drm_property_create_blob(&dev_priv->drm,
> +					sizeof(struct drm_color_lut) * lut_size,
> +					NULL);
> +	if (IS_ERR(blob))
> +		return NULL;
> +
> +	blob_data = blob->data;
> +
> +	I915_WRITE(PREC_PAL_MULTI_SEG_INDEX(pipe), PAL_PREC_AUTO_INCREMENT);
> +
> +	for (i = 0; i < 9; i++) {
> +		val1 = I915_READ(PREC_PAL_MULTI_SEG_DATA(pipe));
> +		val2 = I915_READ(PREC_PAL_MULTI_SEG_DATA(pipe));
> +
> +		blob_data[i].red = REG_FIELD_GET(PAL_PREC_MULTI_SEG_RED_UDW_MASK, val2) << 6 |
> +				   REG_FIELD_GET(PAL_PREC_MULTI_SEG_RED_LDW_MASK, val1);
> +		blob_data[i].green = REG_FIELD_GET(PAL_PREC_MULTI_SEG_GREEN_UDW_MASK, val2) << 6 |
> +				     REG_FIELD_GET(PAL_PREC_MULTI_SEG_GREEN_LDW_MASK, val1);
> +		blob_data[i].blue = REG_FIELD_GET(PAL_PREC_MULTI_SEG_BLUE_UDW_MASK, val2) << 6 |
> +				    REG_FIELD_GET(PAL_PREC_MULTI_SEG_BLUE_LDW_MASK, val1);
> +	}
> +
> +	I915_WRITE(PREC_PAL_INDEX(pipe), PAL_PREC_AUTO_INCREMENT);
> +
> +	for (i = 1; i < 257; i++) {
> +		val1 = I915_READ(PREC_PAL_DATA(pipe));
> +		val2 = I915_READ(PREC_PAL_DATA(pipe));
> +
> +		blob_data[i * 8].red = REG_FIELD_GET(PAL_PREC_MULTI_SEG_RED_UDW_MASK, val2) << 6 |
> +				       REG_FIELD_GET(PAL_PREC_MULTI_SEG_RED_LDW_MASK, val1);
> +		blob_data[i * 8].green = REG_FIELD_GET(PAL_PREC_MULTI_SEG_GREEN_UDW_MASK, val2) << 6 |
> +					 REG_FIELD_GET(PAL_PREC_MULTI_SEG_GREEN_LDW_MASK, val1);
> +		blob_data[i * 8].blue = REG_FIELD_GET(PAL_PREC_MULTI_SEG_BLUE_UDW_MASK, val2) << 6 |
> +					REG_FIELD_GET(PAL_PREC_MULTI_SEG_BLUE_LDW_MASK, val1);
> +	}
> +
> +	for (i = 0; i < 256; i++) {
> +		val1 = I915_READ(PREC_PAL_DATA(pipe));
> +		val2 = I915_READ(PREC_PAL_DATA(pipe));
> +
> +		blob_data[i * 8 * 128].red = REG_FIELD_GET(PAL_PREC_MULTI_SEG_RED_UDW_MASK, val2) << 6 |
> +					     REG_FIELD_GET(PAL_PREC_MULTI_SEG_RED_LDW_MASK, val1);
> +		blob_data[i * 8 * 128].green = REG_FIELD_GET(PAL_PREC_MULTI_SEG_GREEN_UDW_MASK, val2) << 6 |
> +					       REG_FIELD_GET(PAL_PREC_MULTI_SEG_GREEN_LDW_MASK, val1);
> +		blob_data[i * 8 * 128].blue = REG_FIELD_GET(PAL_PREC_MULTI_SEG_BLUE_UDW_MASK, val2) << 6 |
> +					      REG_FIELD_GET(PAL_PREC_MULTI_SEG_BLUE_LDW_MASK, val1);
> +	}
> +
> +	blob_data[lut_size - 1].red = REG_FIELD_GET(PREC_PAL_GC_MAX_RGB_MASK,
> +						    I915_READ(PREC_PAL_GC_MAX(pipe, 0)));
> +	blob_data[lut_size - 1].green = REG_FIELD_GET(PREC_PAL_GC_MAX_RGB_MASK,
> +						      I915_READ(PREC_PAL_GC_MAX(pipe, 1)));
> +	blob_data[lut_size - 1].blue = REG_FIELD_GET(PREC_PAL_GC_MAX_RGB_MASK,
> +						     I915_READ(PREC_PAL_GC_MAX(pipe, 1)));
> +
> +	blob_data = icl_compute_interpolated_gamma_lut_values(blob_data, lut_size);
> +
> +	return blob;
> +}
> +
> +static void icl_read_luts(struct intel_crtc_state *crtc_state)
> +{
> +	if ((crtc_state->gamma_mode & GAMMA_MODE_MODE_MASK) ==
> +	    GAMMA_MODE_MODE_8BIT)
> +		crtc_state->base.gamma_lut = i9xx_read_lut_8(crtc_state);
> +	else if ((crtc_state->gamma_mode & GAMMA_MODE_MODE_MASK) ==
> +		 GAMMA_MODE_MODE_12BIT_MULTI_SEGMENTED)
> +		crtc_state->base.gamma_lut = icl_read_lut_multi_segment(crtc_state);
> +	else
> +		crtc_state->base.gamma_lut = glk_read_lut_10(crtc_state, PAL_PREC_INDEX_VALUE(0));
> +}
> +
>  void intel_color_init(struct intel_crtc *crtc)
>  {
>  	struct drm_i915_private *dev_priv = to_i915(crtc->base.dev);
> @@ -1788,6 +1973,7 @@ void intel_color_init(struct intel_crtc *crtc)
>  
>  		if (INTEL_GEN(dev_priv) >= 11) {
>  			dev_priv->display.load_luts = icl_load_luts;
> +			dev_priv->display.read_luts = icl_read_luts;
>  		} else if (IS_CANNONLAKE(dev_priv) || IS_GEMINILAKE(dev_priv)) {
>  			dev_priv->display.load_luts = glk_load_luts;
>  			dev_priv->display.read_luts = glk_read_luts;
> diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h
> index bf37ece..844dd62 100644
> --- a/drivers/gpu/drm/i915/i915_reg.h
> +++ b/drivers/gpu/drm/i915/i915_reg.h
> @@ -10378,6 +10378,7 @@ enum skl_power_gate {
>  
>  #define PREC_PAL_INDEX(pipe)		_MMIO_PIPE(pipe, _PAL_PREC_INDEX_A, _PAL_PREC_INDEX_B)
>  #define PREC_PAL_DATA(pipe)		_MMIO_PIPE(pipe, _PAL_PREC_DATA_A, _PAL_PREC_DATA_B)
> +#define PREC_PAL_GC_MAX_RGB_MASK	 REG_GENMASK(15, 0)
>  #define PREC_PAL_GC_MAX(pipe, i)	_MMIO(_PIPE(pipe, _PAL_PREC_GC_MAX_A, _PAL_PREC_GC_MAX_B) + (i) * 4)
>  #define PREC_PAL_EXT_GC_MAX(pipe, i)	_MMIO(_PIPE(pipe, _PAL_PREC_EXT_GC_MAX_A, _PAL_PREC_EXT_GC_MAX_B) + (i) * 4)
>  #define PREC_PAL_EXT2_GC_MAX(pipe, i)	_MMIO(_PIPE(pipe, _PAL_PREC_EXT2_GC_MAX_A, _PAL_PREC_EXT2_GC_MAX_B) + (i) * 4)
> @@ -10401,6 +10402,12 @@ enum skl_power_gate {
>  
>  #define _PAL_PREC_MULTI_SEG_DATA_A	0x4A40C
>  #define _PAL_PREC_MULTI_SEG_DATA_B	0x4AC0C
> +#define  PAL_PREC_MULTI_SEG_RED_LDW_MASK   REG_GENMASK(29, 24)
> +#define  PAL_PREC_MULTI_SEG_RED_UDW_MASK   REG_GENMASK(29, 20)
> +#define  PAL_PREC_MULTI_SEG_GREEN_LDW_MASK REG_GENMASK(19, 14)
> +#define  PAL_PREC_MULTI_SEG_GREEN_UDW_MASK REG_GENMASK(19, 10)
> +#define  PAL_PREC_MULTI_SEG_BLUE_LDW_MASK  REG_GENMASK(9, 4)
> +#define  PAL_PREC_MULTI_SEG_BLUE_UDW_MASK  REG_GENMASK(9, 0)
>  
>  #define PREC_PAL_MULTI_SEG_INDEX(pipe)	_MMIO_PIPE(pipe, \
>  					_PAL_PREC_MULTI_SEG_INDEX_A, \
Jani Nikula Sept. 20, 2019, 12:06 p.m. UTC | #2
On Thu, 19 Sep 2019, Swati Sharma <swati2.sharma@intel.com> wrote:
> For icl+, have hw read out to create hw blob of gamma
> lut values. icl+ platforms supports multi segmented gamma
> mode by default, add hw lut creation for this mode.
>
> This will be used to validate gamma programming using dsb
> (display state buffer) which is a tgl specific feature.
>
> Following are the main changes done in this patch:
> 1. gamma_enable checks made specific to platform func()
>    since icl doeesn't support that and enable gamma through mode
> 2. lut[0] and lut[8] enteries should be same superfine and coarse;
>    superfine and fine segments respectively, checked twice-no harm
> 3. Removed temporary lut
> 4. Coarse segment interpolated gamma values loop start from 2
>    instead of 0, since actual h/w values started getting overrided.
>
> v2: -readout code for multisegmented gamma has to come
>      up with some intermediate entries that aren't preserved
>      in hardware (Jani N)
>     -linear interpolation (Ville)
>     -moved common code to check gamma_enable to specific funcs,
>      since icl doesn't support that
> v3: -use u16 instead of __u16 [Jani N]
>     -used single lut [Jani N]
>     -improved and more readable for loops [Jani N]
>     -read values directly to actual locations and then fill gaps [Jani N]
>     -moved cleaning to patch 1 [Jani N]
>     -renamed icl_read_lut_multi_seg() to icl_read_lut_multi_segment to
>      make it similar to icl_load_luts()
>     -renamed icl_compute_interpolated_gamma_blob() to
>      icl_compute_interpolated_gamma_lut_values() more sensible, I guess
>
> Signed-off-by: Swati Sharma <swati2.sharma@intel.com>
> ---
>  drivers/gpu/drm/i915/display/intel_color.c | 216 +++++++++++++++++++++++++++--
>  drivers/gpu/drm/i915/i915_reg.h            |   7 +
>  2 files changed, 208 insertions(+), 15 deletions(-)
>
> diff --git a/drivers/gpu/drm/i915/display/intel_color.c b/drivers/gpu/drm/i915/display/intel_color.c
> index 765482d..ad548ce 100644
> --- a/drivers/gpu/drm/i915/display/intel_color.c
> +++ b/drivers/gpu/drm/i915/display/intel_color.c
> @@ -1371,6 +1371,9 @@ static int icl_color_check(struct intel_crtc_state *crtc_state)
>  
>  static int i9xx_gamma_precision(const struct intel_crtc_state *crtc_state)
>  {
> +	if (!crtc_state->gamma_enable)
> +		return 0;
> +
>  	switch (crtc_state->gamma_mode) {
>  	case GAMMA_MODE_MODE_8BIT:
>  		return 8;
> @@ -1384,6 +1387,9 @@ static int i9xx_gamma_precision(const struct intel_crtc_state *crtc_state)
>  
>  static int ilk_gamma_precision(const struct intel_crtc_state *crtc_state)
>  {
> +	if (!crtc_state->gamma_enable)
> +		return 0;
> +
>  	if ((crtc_state->csc_mode & CSC_POSITION_BEFORE_GAMMA) == 0)
>  		return 0;
>  
> @@ -1400,6 +1406,9 @@ static int ilk_gamma_precision(const struct intel_crtc_state *crtc_state)
>  
>  static int chv_gamma_precision(const struct intel_crtc_state *crtc_state)
>  {
> +	if (!crtc_state->gamma_enable)
> +		return 0;
> +
>  	if (crtc_state->cgm_mode & CGM_PIPE_MODE_GAMMA)
>  		return 10;
>  	else
> @@ -1408,6 +1417,9 @@ static int chv_gamma_precision(const struct intel_crtc_state *crtc_state)
>  
>  static int glk_gamma_precision(const struct intel_crtc_state *crtc_state)
>  {
> +	if (!crtc_state->gamma_enable)
> +		return 0;
> +
>  	switch (crtc_state->gamma_mode) {
>  	case GAMMA_MODE_MODE_8BIT:
>  		return 8;
> @@ -1419,21 +1431,39 @@ static int glk_gamma_precision(const struct intel_crtc_state *crtc_state)
>  	}
>  }
>  
> +static int icl_gamma_precision(const struct intel_crtc_state *crtc_state)
> +{
> +	if ((crtc_state->gamma_mode & POST_CSC_GAMMA_ENABLE) == 0)
> +		return 0;
> +
> +	switch (crtc_state->gamma_mode & GAMMA_MODE_MODE_MASK) {
> +	case GAMMA_MODE_MODE_8BIT:
> +		return 8;
> +	case GAMMA_MODE_MODE_10BIT:
> +		return 10;
> +	case GAMMA_MODE_MODE_12BIT_MULTI_SEGMENTED:
> +		return 16;
> +	default:
> +		MISSING_CASE(crtc_state->gamma_mode);
> +		return 0;
> +	}
> +
> +}
> +
>  int intel_color_get_gamma_bit_precision(const struct intel_crtc_state *crtc_state)
>  {
>  	struct intel_crtc *crtc = to_intel_crtc(crtc_state->base.crtc);
>  	struct drm_i915_private *dev_priv = to_i915(crtc->base.dev);
>  
> -	if (!crtc_state->gamma_enable)
> -		return 0;
> -
>  	if (HAS_GMCH(dev_priv)) {
>  		if (IS_CHERRYVIEW(dev_priv))
>  			return chv_gamma_precision(crtc_state);
>  		else
>  			return i9xx_gamma_precision(crtc_state);
>  	} else {
> -		if (IS_CANNONLAKE(dev_priv) || IS_GEMINILAKE(dev_priv))
> +		if (INTEL_GEN(dev_priv) >= 11)
> +			return icl_gamma_precision(crtc_state);
> +		else if (IS_CANNONLAKE(dev_priv) || IS_GEMINILAKE(dev_priv))
>  			return glk_gamma_precision(crtc_state);
>  		else if (IS_IRONLAKE(dev_priv))
>  			return ilk_gamma_precision(crtc_state);
> @@ -1464,6 +1494,30 @@ static bool intel_color_lut_entry_equal(struct drm_color_lut *lut1,
>  	return true;
>  }
>  
> +static bool intel_color_lut_entry_multi_equal(struct drm_color_lut *lut1,
> +					      struct drm_color_lut *lut2,
> +					      int lut_size, u32 err)
> +{
> +	int i;
> +
> +	for (i = 0; i < 9; i++) {
> +		if (!err_check(&lut1[i], &lut2[i], err))
> +			return false;
> +	}
> +
> +	for (i = 1; i < 257; i++) {
> +		if (!err_check(&lut1[i * 8], &lut2[i * 8], err))
> +			return false;
> +	}
> +
> +	for (i = 0; i < 256; i++) {
> +		if (!err_check(&lut1[i * 8 * 128], &lut2[i * 8 * 128], err))
> +			return false;
> +	}
> +
> +	return true;
> +}
> +
>  bool intel_color_lut_equal(struct drm_property_blob *blob1,
>  			   struct drm_property_blob *blob2,
>  			   u32 gamma_mode, u32 bit_precision)
> @@ -1482,16 +1536,8 @@ bool intel_color_lut_equal(struct drm_property_blob *blob1,
>  	lut_size2 = drm_color_lut_size(blob2);
>  
>  	/* check sw and hw lut size */
> -	switch (gamma_mode) {
> -	case GAMMA_MODE_MODE_8BIT:
> -	case GAMMA_MODE_MODE_10BIT:
> -		if (lut_size1 != lut_size2)
> -			return false;
> -		break;
> -	default:
> -		MISSING_CASE(gamma_mode);
> -			return false;
> -	}
> +	if (lut_size1 != lut_size2)
> +		return false;
>  
>  	lut1 = blob1->data;
>  	lut2 = blob2->data;
> @@ -1499,13 +1545,18 @@ bool intel_color_lut_equal(struct drm_property_blob *blob1,
>  	err = 0xffff >> bit_precision;
>  
>  	/* check sw and hw lut entry to be equal */
> -	switch (gamma_mode) {
> +	switch (gamma_mode & GAMMA_MODE_MODE_MASK) {
>  	case GAMMA_MODE_MODE_8BIT:
>  	case GAMMA_MODE_MODE_10BIT:
>  		if (!intel_color_lut_entry_equal(lut1, lut2,
>  						 lut_size2, err))
>  			return false;
>  		break;
> +	case GAMMA_MODE_MODE_12BIT_MULTI_SEGMENTED:
> +		if (!intel_color_lut_entry_multi_equal(lut1, lut2,
> +						       lut_size2, err))
> +			return false;
> +		break;
>  	default:
>  		MISSING_CASE(gamma_mode);
>  			return false;
> @@ -1745,6 +1796,140 @@ static void glk_read_luts(struct intel_crtc_state *crtc_state)
>  		crtc_state->base.gamma_lut = glk_read_lut_10(crtc_state, PAL_PREC_INDEX_VALUE(0));
>  }
>  
> +static u16 cal_step_size(u16 end_val, u16 start_val, int steps)
> +{
> +	return ((end_val - start_val) / steps);
> +}
> +
> +static struct drm_color_lut *
> +icl_compute_interpolated_gamma_lut_values(struct drm_color_lut *lut, u32 lut_size)
> +{
> +	u16 red_step_size, green_step_size, blue_step_size;
> +	int start, end, steps;
> +	int i, j;
> +
> +	for (i = 1; i < 257 - 1; i++) {
> +		start = i * 8;
> +		end = (i + 1) * 8;
> +		steps = end - start;
> +
> +		red_step_size = cal_step_size(lut[end].red, lut[start].red, steps);
> +		green_step_size = cal_step_size(lut[end].green, lut[start].green, steps);
> +		blue_step_size = cal_step_size(lut[end].blue, lut[start].blue, steps);
> +
> +		for (j = start + 1; j < end; j++) {
> +			lut[j].red = lut[j - 1].red + red_step_size;
> +			lut[j].green = lut[j - 1].green + green_step_size;
> +			lut[j].blue = lut[j - 1].blue + blue_step_size;
> +
> +			i++;

Why would this be needed?

> +		}
> +	}
> +
> +	for (i = 2; i < 256 - 1; i++) {
> +		start = i * 8 * 128;
> +		end = (i + 1) * 8 * 128;
> +		steps = end - start;
> +
> +		red_step_size = cal_step_size(lut[end].red, lut[start].red, steps);
> +		green_step_size = cal_step_size(lut[end].green, lut[start].green, steps);
> +		blue_step_size = cal_step_size(lut[end].blue, lut[start].blue, steps);
> +
> +		for (j = start + 1; j < end; j++) {
> +			lut[j].red = lut[j - 1].red + red_step_size;
> +			lut[j].green = lut[j - 1].green + green_step_size;
> +			lut[j].blue = lut[j - 1].blue + blue_step_size;
> +
> +			i++;

Ditto.

I think everything else checks out. With those fixed,

Reviewed-by: Jani Nikula <jani.nikula@intel.com>


> +		}
> +	}
> +
> +	return lut;
> +}
> +
> +static struct drm_property_blob *
> +icl_read_lut_multi_segment(const struct intel_crtc_state *crtc_state)
> +{
> +	struct intel_crtc *crtc = to_intel_crtc(crtc_state->base.crtc);
> +	struct drm_i915_private *dev_priv = to_i915(crtc->base.dev);
> +	int lut_size = INTEL_INFO(dev_priv)->color.gamma_lut_size;
> +	enum pipe pipe = crtc->pipe;
> +	struct drm_property_blob *blob;
> +	struct drm_color_lut *blob_data;
> +	u32 i, val1, val2;
> +
> +	blob = drm_property_create_blob(&dev_priv->drm,
> +					sizeof(struct drm_color_lut) * lut_size,
> +					NULL);
> +	if (IS_ERR(blob))
> +		return NULL;
> +
> +	blob_data = blob->data;
> +
> +	I915_WRITE(PREC_PAL_MULTI_SEG_INDEX(pipe), PAL_PREC_AUTO_INCREMENT);
> +
> +	for (i = 0; i < 9; i++) {
> +		val1 = I915_READ(PREC_PAL_MULTI_SEG_DATA(pipe));
> +		val2 = I915_READ(PREC_PAL_MULTI_SEG_DATA(pipe));
> +
> +		blob_data[i].red = REG_FIELD_GET(PAL_PREC_MULTI_SEG_RED_UDW_MASK, val2) << 6 |
> +				   REG_FIELD_GET(PAL_PREC_MULTI_SEG_RED_LDW_MASK, val1);
> +		blob_data[i].green = REG_FIELD_GET(PAL_PREC_MULTI_SEG_GREEN_UDW_MASK, val2) << 6 |
> +				     REG_FIELD_GET(PAL_PREC_MULTI_SEG_GREEN_LDW_MASK, val1);
> +		blob_data[i].blue = REG_FIELD_GET(PAL_PREC_MULTI_SEG_BLUE_UDW_MASK, val2) << 6 |
> +				    REG_FIELD_GET(PAL_PREC_MULTI_SEG_BLUE_LDW_MASK, val1);
> +	}
> +
> +	I915_WRITE(PREC_PAL_INDEX(pipe), PAL_PREC_AUTO_INCREMENT);
> +
> +	for (i = 1; i < 257; i++) {
> +		val1 = I915_READ(PREC_PAL_DATA(pipe));
> +		val2 = I915_READ(PREC_PAL_DATA(pipe));
> +
> +		blob_data[i * 8].red = REG_FIELD_GET(PAL_PREC_MULTI_SEG_RED_UDW_MASK, val2) << 6 |
> +				       REG_FIELD_GET(PAL_PREC_MULTI_SEG_RED_LDW_MASK, val1);
> +		blob_data[i * 8].green = REG_FIELD_GET(PAL_PREC_MULTI_SEG_GREEN_UDW_MASK, val2) << 6 |
> +					 REG_FIELD_GET(PAL_PREC_MULTI_SEG_GREEN_LDW_MASK, val1);
> +		blob_data[i * 8].blue = REG_FIELD_GET(PAL_PREC_MULTI_SEG_BLUE_UDW_MASK, val2) << 6 |
> +					REG_FIELD_GET(PAL_PREC_MULTI_SEG_BLUE_LDW_MASK, val1);
> +	}
> +
> +	for (i = 0; i < 256; i++) {
> +		val1 = I915_READ(PREC_PAL_DATA(pipe));
> +		val2 = I915_READ(PREC_PAL_DATA(pipe));
> +
> +		blob_data[i * 8 * 128].red = REG_FIELD_GET(PAL_PREC_MULTI_SEG_RED_UDW_MASK, val2) << 6 |
> +					     REG_FIELD_GET(PAL_PREC_MULTI_SEG_RED_LDW_MASK, val1);
> +		blob_data[i * 8 * 128].green = REG_FIELD_GET(PAL_PREC_MULTI_SEG_GREEN_UDW_MASK, val2) << 6 |
> +					       REG_FIELD_GET(PAL_PREC_MULTI_SEG_GREEN_LDW_MASK, val1);
> +		blob_data[i * 8 * 128].blue = REG_FIELD_GET(PAL_PREC_MULTI_SEG_BLUE_UDW_MASK, val2) << 6 |
> +					      REG_FIELD_GET(PAL_PREC_MULTI_SEG_BLUE_LDW_MASK, val1);
> +	}
> +
> +	blob_data[lut_size - 1].red = REG_FIELD_GET(PREC_PAL_GC_MAX_RGB_MASK,
> +						    I915_READ(PREC_PAL_GC_MAX(pipe, 0)));
> +	blob_data[lut_size - 1].green = REG_FIELD_GET(PREC_PAL_GC_MAX_RGB_MASK,
> +						      I915_READ(PREC_PAL_GC_MAX(pipe, 1)));
> +	blob_data[lut_size - 1].blue = REG_FIELD_GET(PREC_PAL_GC_MAX_RGB_MASK,
> +						     I915_READ(PREC_PAL_GC_MAX(pipe, 1)));
> +
> +	blob_data = icl_compute_interpolated_gamma_lut_values(blob_data, lut_size);
> +
> +	return blob;
> +}
> +
> +static void icl_read_luts(struct intel_crtc_state *crtc_state)
> +{
> +	if ((crtc_state->gamma_mode & GAMMA_MODE_MODE_MASK) ==
> +	    GAMMA_MODE_MODE_8BIT)
> +		crtc_state->base.gamma_lut = i9xx_read_lut_8(crtc_state);
> +	else if ((crtc_state->gamma_mode & GAMMA_MODE_MODE_MASK) ==
> +		 GAMMA_MODE_MODE_12BIT_MULTI_SEGMENTED)
> +		crtc_state->base.gamma_lut = icl_read_lut_multi_segment(crtc_state);
> +	else
> +		crtc_state->base.gamma_lut = glk_read_lut_10(crtc_state, PAL_PREC_INDEX_VALUE(0));
> +}
> +
>  void intel_color_init(struct intel_crtc *crtc)
>  {
>  	struct drm_i915_private *dev_priv = to_i915(crtc->base.dev);
> @@ -1788,6 +1973,7 @@ void intel_color_init(struct intel_crtc *crtc)
>  
>  		if (INTEL_GEN(dev_priv) >= 11) {
>  			dev_priv->display.load_luts = icl_load_luts;
> +			dev_priv->display.read_luts = icl_read_luts;
>  		} else if (IS_CANNONLAKE(dev_priv) || IS_GEMINILAKE(dev_priv)) {
>  			dev_priv->display.load_luts = glk_load_luts;
>  			dev_priv->display.read_luts = glk_read_luts;
> diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h
> index bf37ece..844dd62 100644
> --- a/drivers/gpu/drm/i915/i915_reg.h
> +++ b/drivers/gpu/drm/i915/i915_reg.h
> @@ -10378,6 +10378,7 @@ enum skl_power_gate {
>  
>  #define PREC_PAL_INDEX(pipe)		_MMIO_PIPE(pipe, _PAL_PREC_INDEX_A, _PAL_PREC_INDEX_B)
>  #define PREC_PAL_DATA(pipe)		_MMIO_PIPE(pipe, _PAL_PREC_DATA_A, _PAL_PREC_DATA_B)
> +#define PREC_PAL_GC_MAX_RGB_MASK	 REG_GENMASK(15, 0)
>  #define PREC_PAL_GC_MAX(pipe, i)	_MMIO(_PIPE(pipe, _PAL_PREC_GC_MAX_A, _PAL_PREC_GC_MAX_B) + (i) * 4)
>  #define PREC_PAL_EXT_GC_MAX(pipe, i)	_MMIO(_PIPE(pipe, _PAL_PREC_EXT_GC_MAX_A, _PAL_PREC_EXT_GC_MAX_B) + (i) * 4)
>  #define PREC_PAL_EXT2_GC_MAX(pipe, i)	_MMIO(_PIPE(pipe, _PAL_PREC_EXT2_GC_MAX_A, _PAL_PREC_EXT2_GC_MAX_B) + (i) * 4)
> @@ -10401,6 +10402,12 @@ enum skl_power_gate {
>  
>  #define _PAL_PREC_MULTI_SEG_DATA_A	0x4A40C
>  #define _PAL_PREC_MULTI_SEG_DATA_B	0x4AC0C
> +#define  PAL_PREC_MULTI_SEG_RED_LDW_MASK   REG_GENMASK(29, 24)
> +#define  PAL_PREC_MULTI_SEG_RED_UDW_MASK   REG_GENMASK(29, 20)
> +#define  PAL_PREC_MULTI_SEG_GREEN_LDW_MASK REG_GENMASK(19, 14)
> +#define  PAL_PREC_MULTI_SEG_GREEN_UDW_MASK REG_GENMASK(19, 10)
> +#define  PAL_PREC_MULTI_SEG_BLUE_LDW_MASK  REG_GENMASK(9, 4)
> +#define  PAL_PREC_MULTI_SEG_BLUE_UDW_MASK  REG_GENMASK(9, 0)
>  
>  #define PREC_PAL_MULTI_SEG_INDEX(pipe)	_MMIO_PIPE(pipe, \
>  					_PAL_PREC_MULTI_SEG_INDEX_A, \

Patch
diff mbox series

diff --git a/drivers/gpu/drm/i915/display/intel_color.c b/drivers/gpu/drm/i915/display/intel_color.c
index 765482d..ad548ce 100644
--- a/drivers/gpu/drm/i915/display/intel_color.c
+++ b/drivers/gpu/drm/i915/display/intel_color.c
@@ -1371,6 +1371,9 @@  static int icl_color_check(struct intel_crtc_state *crtc_state)
 
 static int i9xx_gamma_precision(const struct intel_crtc_state *crtc_state)
 {
+	if (!crtc_state->gamma_enable)
+		return 0;
+
 	switch (crtc_state->gamma_mode) {
 	case GAMMA_MODE_MODE_8BIT:
 		return 8;
@@ -1384,6 +1387,9 @@  static int i9xx_gamma_precision(const struct intel_crtc_state *crtc_state)
 
 static int ilk_gamma_precision(const struct intel_crtc_state *crtc_state)
 {
+	if (!crtc_state->gamma_enable)
+		return 0;
+
 	if ((crtc_state->csc_mode & CSC_POSITION_BEFORE_GAMMA) == 0)
 		return 0;
 
@@ -1400,6 +1406,9 @@  static int ilk_gamma_precision(const struct intel_crtc_state *crtc_state)
 
 static int chv_gamma_precision(const struct intel_crtc_state *crtc_state)
 {
+	if (!crtc_state->gamma_enable)
+		return 0;
+
 	if (crtc_state->cgm_mode & CGM_PIPE_MODE_GAMMA)
 		return 10;
 	else
@@ -1408,6 +1417,9 @@  static int chv_gamma_precision(const struct intel_crtc_state *crtc_state)
 
 static int glk_gamma_precision(const struct intel_crtc_state *crtc_state)
 {
+	if (!crtc_state->gamma_enable)
+		return 0;
+
 	switch (crtc_state->gamma_mode) {
 	case GAMMA_MODE_MODE_8BIT:
 		return 8;
@@ -1419,21 +1431,39 @@  static int glk_gamma_precision(const struct intel_crtc_state *crtc_state)
 	}
 }
 
+static int icl_gamma_precision(const struct intel_crtc_state *crtc_state)
+{
+	if ((crtc_state->gamma_mode & POST_CSC_GAMMA_ENABLE) == 0)
+		return 0;
+
+	switch (crtc_state->gamma_mode & GAMMA_MODE_MODE_MASK) {
+	case GAMMA_MODE_MODE_8BIT:
+		return 8;
+	case GAMMA_MODE_MODE_10BIT:
+		return 10;
+	case GAMMA_MODE_MODE_12BIT_MULTI_SEGMENTED:
+		return 16;
+	default:
+		MISSING_CASE(crtc_state->gamma_mode);
+		return 0;
+	}
+
+}
+
 int intel_color_get_gamma_bit_precision(const struct intel_crtc_state *crtc_state)
 {
 	struct intel_crtc *crtc = to_intel_crtc(crtc_state->base.crtc);
 	struct drm_i915_private *dev_priv = to_i915(crtc->base.dev);
 
-	if (!crtc_state->gamma_enable)
-		return 0;
-
 	if (HAS_GMCH(dev_priv)) {
 		if (IS_CHERRYVIEW(dev_priv))
 			return chv_gamma_precision(crtc_state);
 		else
 			return i9xx_gamma_precision(crtc_state);
 	} else {
-		if (IS_CANNONLAKE(dev_priv) || IS_GEMINILAKE(dev_priv))
+		if (INTEL_GEN(dev_priv) >= 11)
+			return icl_gamma_precision(crtc_state);
+		else if (IS_CANNONLAKE(dev_priv) || IS_GEMINILAKE(dev_priv))
 			return glk_gamma_precision(crtc_state);
 		else if (IS_IRONLAKE(dev_priv))
 			return ilk_gamma_precision(crtc_state);
@@ -1464,6 +1494,30 @@  static bool intel_color_lut_entry_equal(struct drm_color_lut *lut1,
 	return true;
 }
 
+static bool intel_color_lut_entry_multi_equal(struct drm_color_lut *lut1,
+					      struct drm_color_lut *lut2,
+					      int lut_size, u32 err)
+{
+	int i;
+
+	for (i = 0; i < 9; i++) {
+		if (!err_check(&lut1[i], &lut2[i], err))
+			return false;
+	}
+
+	for (i = 1; i < 257; i++) {
+		if (!err_check(&lut1[i * 8], &lut2[i * 8], err))
+			return false;
+	}
+
+	for (i = 0; i < 256; i++) {
+		if (!err_check(&lut1[i * 8 * 128], &lut2[i * 8 * 128], err))
+			return false;
+	}
+
+	return true;
+}
+
 bool intel_color_lut_equal(struct drm_property_blob *blob1,
 			   struct drm_property_blob *blob2,
 			   u32 gamma_mode, u32 bit_precision)
@@ -1482,16 +1536,8 @@  bool intel_color_lut_equal(struct drm_property_blob *blob1,
 	lut_size2 = drm_color_lut_size(blob2);
 
 	/* check sw and hw lut size */
-	switch (gamma_mode) {
-	case GAMMA_MODE_MODE_8BIT:
-	case GAMMA_MODE_MODE_10BIT:
-		if (lut_size1 != lut_size2)
-			return false;
-		break;
-	default:
-		MISSING_CASE(gamma_mode);
-			return false;
-	}
+	if (lut_size1 != lut_size2)
+		return false;
 
 	lut1 = blob1->data;
 	lut2 = blob2->data;
@@ -1499,13 +1545,18 @@  bool intel_color_lut_equal(struct drm_property_blob *blob1,
 	err = 0xffff >> bit_precision;
 
 	/* check sw and hw lut entry to be equal */
-	switch (gamma_mode) {
+	switch (gamma_mode & GAMMA_MODE_MODE_MASK) {
 	case GAMMA_MODE_MODE_8BIT:
 	case GAMMA_MODE_MODE_10BIT:
 		if (!intel_color_lut_entry_equal(lut1, lut2,
 						 lut_size2, err))
 			return false;
 		break;
+	case GAMMA_MODE_MODE_12BIT_MULTI_SEGMENTED:
+		if (!intel_color_lut_entry_multi_equal(lut1, lut2,
+						       lut_size2, err))
+			return false;
+		break;
 	default:
 		MISSING_CASE(gamma_mode);
 			return false;
@@ -1745,6 +1796,140 @@  static void glk_read_luts(struct intel_crtc_state *crtc_state)
 		crtc_state->base.gamma_lut = glk_read_lut_10(crtc_state, PAL_PREC_INDEX_VALUE(0));
 }
 
+static u16 cal_step_size(u16 end_val, u16 start_val, int steps)
+{
+	return ((end_val - start_val) / steps);
+}
+
+static struct drm_color_lut *
+icl_compute_interpolated_gamma_lut_values(struct drm_color_lut *lut, u32 lut_size)
+{
+	u16 red_step_size, green_step_size, blue_step_size;
+	int start, end, steps;
+	int i, j;
+
+	for (i = 1; i < 257 - 1; i++) {
+		start = i * 8;
+		end = (i + 1) * 8;
+		steps = end - start;
+
+		red_step_size = cal_step_size(lut[end].red, lut[start].red, steps);
+		green_step_size = cal_step_size(lut[end].green, lut[start].green, steps);
+		blue_step_size = cal_step_size(lut[end].blue, lut[start].blue, steps);
+
+		for (j = start + 1; j < end; j++) {
+			lut[j].red = lut[j - 1].red + red_step_size;
+			lut[j].green = lut[j - 1].green + green_step_size;
+			lut[j].blue = lut[j - 1].blue + blue_step_size;
+
+			i++;
+		}
+	}
+
+	for (i = 2; i < 256 - 1; i++) {
+		start = i * 8 * 128;
+		end = (i + 1) * 8 * 128;
+		steps = end - start;
+
+		red_step_size = cal_step_size(lut[end].red, lut[start].red, steps);
+		green_step_size = cal_step_size(lut[end].green, lut[start].green, steps);
+		blue_step_size = cal_step_size(lut[end].blue, lut[start].blue, steps);
+
+		for (j = start + 1; j < end; j++) {
+			lut[j].red = lut[j - 1].red + red_step_size;
+			lut[j].green = lut[j - 1].green + green_step_size;
+			lut[j].blue = lut[j - 1].blue + blue_step_size;
+
+			i++;
+		}
+	}
+
+	return lut;
+}
+
+static struct drm_property_blob *
+icl_read_lut_multi_segment(const struct intel_crtc_state *crtc_state)
+{
+	struct intel_crtc *crtc = to_intel_crtc(crtc_state->base.crtc);
+	struct drm_i915_private *dev_priv = to_i915(crtc->base.dev);
+	int lut_size = INTEL_INFO(dev_priv)->color.gamma_lut_size;
+	enum pipe pipe = crtc->pipe;
+	struct drm_property_blob *blob;
+	struct drm_color_lut *blob_data;
+	u32 i, val1, val2;
+
+	blob = drm_property_create_blob(&dev_priv->drm,
+					sizeof(struct drm_color_lut) * lut_size,
+					NULL);
+	if (IS_ERR(blob))
+		return NULL;
+
+	blob_data = blob->data;
+
+	I915_WRITE(PREC_PAL_MULTI_SEG_INDEX(pipe), PAL_PREC_AUTO_INCREMENT);
+
+	for (i = 0; i < 9; i++) {
+		val1 = I915_READ(PREC_PAL_MULTI_SEG_DATA(pipe));
+		val2 = I915_READ(PREC_PAL_MULTI_SEG_DATA(pipe));
+
+		blob_data[i].red = REG_FIELD_GET(PAL_PREC_MULTI_SEG_RED_UDW_MASK, val2) << 6 |
+				   REG_FIELD_GET(PAL_PREC_MULTI_SEG_RED_LDW_MASK, val1);
+		blob_data[i].green = REG_FIELD_GET(PAL_PREC_MULTI_SEG_GREEN_UDW_MASK, val2) << 6 |
+				     REG_FIELD_GET(PAL_PREC_MULTI_SEG_GREEN_LDW_MASK, val1);
+		blob_data[i].blue = REG_FIELD_GET(PAL_PREC_MULTI_SEG_BLUE_UDW_MASK, val2) << 6 |
+				    REG_FIELD_GET(PAL_PREC_MULTI_SEG_BLUE_LDW_MASK, val1);
+	}
+
+	I915_WRITE(PREC_PAL_INDEX(pipe), PAL_PREC_AUTO_INCREMENT);
+
+	for (i = 1; i < 257; i++) {
+		val1 = I915_READ(PREC_PAL_DATA(pipe));
+		val2 = I915_READ(PREC_PAL_DATA(pipe));
+
+		blob_data[i * 8].red = REG_FIELD_GET(PAL_PREC_MULTI_SEG_RED_UDW_MASK, val2) << 6 |
+				       REG_FIELD_GET(PAL_PREC_MULTI_SEG_RED_LDW_MASK, val1);
+		blob_data[i * 8].green = REG_FIELD_GET(PAL_PREC_MULTI_SEG_GREEN_UDW_MASK, val2) << 6 |
+					 REG_FIELD_GET(PAL_PREC_MULTI_SEG_GREEN_LDW_MASK, val1);
+		blob_data[i * 8].blue = REG_FIELD_GET(PAL_PREC_MULTI_SEG_BLUE_UDW_MASK, val2) << 6 |
+					REG_FIELD_GET(PAL_PREC_MULTI_SEG_BLUE_LDW_MASK, val1);
+	}
+
+	for (i = 0; i < 256; i++) {
+		val1 = I915_READ(PREC_PAL_DATA(pipe));
+		val2 = I915_READ(PREC_PAL_DATA(pipe));
+
+		blob_data[i * 8 * 128].red = REG_FIELD_GET(PAL_PREC_MULTI_SEG_RED_UDW_MASK, val2) << 6 |
+					     REG_FIELD_GET(PAL_PREC_MULTI_SEG_RED_LDW_MASK, val1);
+		blob_data[i * 8 * 128].green = REG_FIELD_GET(PAL_PREC_MULTI_SEG_GREEN_UDW_MASK, val2) << 6 |
+					       REG_FIELD_GET(PAL_PREC_MULTI_SEG_GREEN_LDW_MASK, val1);
+		blob_data[i * 8 * 128].blue = REG_FIELD_GET(PAL_PREC_MULTI_SEG_BLUE_UDW_MASK, val2) << 6 |
+					      REG_FIELD_GET(PAL_PREC_MULTI_SEG_BLUE_LDW_MASK, val1);
+	}
+
+	blob_data[lut_size - 1].red = REG_FIELD_GET(PREC_PAL_GC_MAX_RGB_MASK,
+						    I915_READ(PREC_PAL_GC_MAX(pipe, 0)));
+	blob_data[lut_size - 1].green = REG_FIELD_GET(PREC_PAL_GC_MAX_RGB_MASK,
+						      I915_READ(PREC_PAL_GC_MAX(pipe, 1)));
+	blob_data[lut_size - 1].blue = REG_FIELD_GET(PREC_PAL_GC_MAX_RGB_MASK,
+						     I915_READ(PREC_PAL_GC_MAX(pipe, 1)));
+
+	blob_data = icl_compute_interpolated_gamma_lut_values(blob_data, lut_size);
+
+	return blob;
+}
+
+static void icl_read_luts(struct intel_crtc_state *crtc_state)
+{
+	if ((crtc_state->gamma_mode & GAMMA_MODE_MODE_MASK) ==
+	    GAMMA_MODE_MODE_8BIT)
+		crtc_state->base.gamma_lut = i9xx_read_lut_8(crtc_state);
+	else if ((crtc_state->gamma_mode & GAMMA_MODE_MODE_MASK) ==
+		 GAMMA_MODE_MODE_12BIT_MULTI_SEGMENTED)
+		crtc_state->base.gamma_lut = icl_read_lut_multi_segment(crtc_state);
+	else
+		crtc_state->base.gamma_lut = glk_read_lut_10(crtc_state, PAL_PREC_INDEX_VALUE(0));
+}
+
 void intel_color_init(struct intel_crtc *crtc)
 {
 	struct drm_i915_private *dev_priv = to_i915(crtc->base.dev);
@@ -1788,6 +1973,7 @@  void intel_color_init(struct intel_crtc *crtc)
 
 		if (INTEL_GEN(dev_priv) >= 11) {
 			dev_priv->display.load_luts = icl_load_luts;
+			dev_priv->display.read_luts = icl_read_luts;
 		} else if (IS_CANNONLAKE(dev_priv) || IS_GEMINILAKE(dev_priv)) {
 			dev_priv->display.load_luts = glk_load_luts;
 			dev_priv->display.read_luts = glk_read_luts;
diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h
index bf37ece..844dd62 100644
--- a/drivers/gpu/drm/i915/i915_reg.h
+++ b/drivers/gpu/drm/i915/i915_reg.h
@@ -10378,6 +10378,7 @@  enum skl_power_gate {
 
 #define PREC_PAL_INDEX(pipe)		_MMIO_PIPE(pipe, _PAL_PREC_INDEX_A, _PAL_PREC_INDEX_B)
 #define PREC_PAL_DATA(pipe)		_MMIO_PIPE(pipe, _PAL_PREC_DATA_A, _PAL_PREC_DATA_B)
+#define PREC_PAL_GC_MAX_RGB_MASK	 REG_GENMASK(15, 0)
 #define PREC_PAL_GC_MAX(pipe, i)	_MMIO(_PIPE(pipe, _PAL_PREC_GC_MAX_A, _PAL_PREC_GC_MAX_B) + (i) * 4)
 #define PREC_PAL_EXT_GC_MAX(pipe, i)	_MMIO(_PIPE(pipe, _PAL_PREC_EXT_GC_MAX_A, _PAL_PREC_EXT_GC_MAX_B) + (i) * 4)
 #define PREC_PAL_EXT2_GC_MAX(pipe, i)	_MMIO(_PIPE(pipe, _PAL_PREC_EXT2_GC_MAX_A, _PAL_PREC_EXT2_GC_MAX_B) + (i) * 4)
@@ -10401,6 +10402,12 @@  enum skl_power_gate {
 
 #define _PAL_PREC_MULTI_SEG_DATA_A	0x4A40C
 #define _PAL_PREC_MULTI_SEG_DATA_B	0x4AC0C
+#define  PAL_PREC_MULTI_SEG_RED_LDW_MASK   REG_GENMASK(29, 24)
+#define  PAL_PREC_MULTI_SEG_RED_UDW_MASK   REG_GENMASK(29, 20)
+#define  PAL_PREC_MULTI_SEG_GREEN_LDW_MASK REG_GENMASK(19, 14)
+#define  PAL_PREC_MULTI_SEG_GREEN_UDW_MASK REG_GENMASK(19, 10)
+#define  PAL_PREC_MULTI_SEG_BLUE_LDW_MASK  REG_GENMASK(9, 4)
+#define  PAL_PREC_MULTI_SEG_BLUE_UDW_MASK  REG_GENMASK(9, 0)
 
 #define PREC_PAL_MULTI_SEG_INDEX(pipe)	_MMIO_PIPE(pipe, \
 					_PAL_PREC_MULTI_SEG_INDEX_A, \