[Intel-gfx] [v2 5/7] drm/i915/icl: Add support for multi segmented gamma mode

Shankar, Uma uma.shankar at intel.com
Mon Apr 8 12:51:13 UTC 2019



>-----Original Message-----
>From: Ville Syrjälä [mailto:ville.syrjala at linux.intel.com]
>Sent: Monday, April 8, 2019 3:50 PM
>To: Shankar, Uma <uma.shankar at intel.com>
>Cc: intel-gfx at lists.freedesktop.org; dri-devel at lists.freedesktop.org;
>dcastagna at chromium.org; seanpaul at chromium.org; Syrjala, Ville
><ville.syrjala at intel.com>; harry.wentland at amd.com; Lankhorst, Maarten
><maarten.lankhorst at intel.com>
>Subject: Re: [Intel-gfx] [v2 5/7] drm/i915/icl: Add support for multi segmented
>gamma mode
>
>On Mon, Apr 01, 2019 at 11:00:09PM +0530, Uma Shankar wrote:
>> Gen11 introduced a new gamma mode i.e, multi segmented gamma mode.
>> Added support for the same.
>>
>> Signed-off-by: Uma Shankar <uma.shankar at intel.com>
>> ---
>>  drivers/gpu/drm/i915/intel_color.c | 161
>++++++++++++++++++++++++++++++++++++-
>>  include/drm/drm_crtc.h             |   3 +
>>  2 files changed, 161 insertions(+), 3 deletions(-)
>>
>> diff --git a/drivers/gpu/drm/i915/intel_color.c
>> b/drivers/gpu/drm/i915/intel_color.c
>> index 84d93ec..d81de32 100644
>> --- a/drivers/gpu/drm/i915/intel_color.c
>> +++ b/drivers/gpu/drm/i915/intel_color.c
>> @@ -57,6 +57,12 @@
>>
>>  #define ILK_CSC_POSTOFF_LIMITED_RANGE (16 * (1 << 12) / 255)
>>
>> +#define LEGACY_PALETTE_MODE_8BIT               BIT(0)
>> +#define PRECISION_PALETTE_MODE_10BIT           BIT(1)
>> +#define INTERPOLATED_GAMMA_MODE_12BIT          BIT(2)
>> +#define MULTI_SEGMENTED_GAMMA_MODE_12BIT       BIT(3)
>> +#define SPLIT_GAMMA_MODE_12BIT                 BIT(4)
>> +
>>  static const u16 ilk_csc_off_zero[3] = {};
>>
>>  static const u16 ilk_csc_coeff_identity[9] = { @@ -92,6 +98,9 @@
>>  	0x0800, 0x0100, 0x0800,
>>  };
>>
>> +#define GEN11_GET_MS10BITS_OF_LUT(lut) (((lut) >> 6) & 0x3FF) #define
>> +GEN11_GET_LS6BITS_OF_LUT(lut)  ((lut) & 0x3F)
>
>I think this is just the ilk+ 12.4 format. IIRC I had some kind of
>ilk_lut_12p4_ldw/udw() funcs for these in my branch somewhere.
>I'd like to see somehting like that in this patch.

Sure, I will add those and use the same. Something similar to (i965_lut_10p6_udw)

>> +
>>  static bool lut_is_legacy(const struct drm_property_blob *lut)  {
>>  	return drm_color_lut_size(lut) == LEGACY_LUT_LENGTH; @@ -670,16
>> +679,149 @@ static void glk_load_luts(const struct intel_crtc_state *crtc_state)
>>  		bdw_load_gamma_lut(crtc_state, 0);
>>  }
>>
>> +static void icl_program_coarse_segment_lut(const struct intel_crtc_state
>> +					   *crtc_state,
>> +					   struct drm_color_lut *gamma_lut,
>> +					   u32 offset)
>
>I think to match the current pattern we should have something like:
>
>icl_load_lut_coarse_segment(struct intel_crtc *crtc,
>                            const struct drm_property_blob *blob);
>icl_load_lut_fine_segment(struct intel_crtc *crtc,
>                          const struct drm_property_blob *blob);

Ok, will update this.

>> +{
>> +	struct intel_crtc *crtc = to_intel_crtc(crtc_state->base.crtc);
>> +	struct drm_i915_private *dev_priv = to_i915(crtc->base.dev);
>> +	const struct drm_color_lut *lut = gamma_lut;
>> +	enum pipe pipe = crtc->pipe;
>> +	u32 i, lut_size, word;
>> +
>> +	WARN_ON(offset & ~PAL_PREC_INDEX_VALUE_MASK);
>> +
>> +	I915_WRITE(PREC_PAL_INDEX(pipe),
>> +		   (offset ? PAL_PREC_SPLIT_MODE : 0) |
>> +		   PAL_PREC_AUTO_INCREMENT |
>> +		   offset);
>> +
>> +	if (lut && crtc_state->base.gamma_mode_type ==
>> +				MULTI_SEGMENTED_GAMMA_MODE_12BIT) {
>> +		lut_size = 9 + 514;
>> +		for (i = 9; i < lut_size; i++) {
>> +			/* For Even Index */
>> +			word = (GEN11_GET_LS6BITS_OF_LUT(lut[i].red) << 20) |
>> +				(GEN11_GET_LS6BITS_OF_LUT(lut[i].green) << 10) |
>> +				GEN11_GET_LS6BITS_OF_LUT(lut[i].blue);
>> +
>> +			I915_WRITE(PREC_PAL_DATA(pipe), word);
>> +
>> +			/* For ODD index */
>> +			word = (GEN11_GET_MS10BITS_OF_LUT(lut[i].red) << 20) |
>> +				(GEN11_GET_MS10BITS_OF_LUT(lut[i].green) << 10)
>|
>> +				GEN11_GET_MS10BITS_OF_LUT(lut[i].blue);
>> +
>> +			I915_WRITE(PREC_PAL_DATA(pipe), word);
>> +		}
>> +	}
>> +
>> +	/*
>> +	 * Program the max register to clamp values > 1.0.
>> +	 * ToDo: Extend the ABI to be able to program values
>> +	 * from 1.0
>> +	 */
>> +	I915_WRITE(PREC_PAL_GC_MAX(pipe, 0), (1 << 16));
>> +	I915_WRITE(PREC_PAL_GC_MAX(pipe, 1), (1 << 16));
>> +	I915_WRITE(PREC_PAL_GC_MAX(pipe, 2), (1 << 16));
>> +
>> +	/*
>> +	 * Program the max register to clamp values > 1.0.
>> +	 * ToDo: Extend the ABI to be able to program values
>> +	 * from 1.0 to 3.0
>> +	 */
>> +	I915_WRITE(PREC_PAL_EXT_GC_MAX(pipe, 0), (1 << 16));
>> +	I915_WRITE(PREC_PAL_EXT_GC_MAX(pipe, 1), (1 << 16));
>> +	I915_WRITE(PREC_PAL_EXT_GC_MAX(pipe, 2), (1 << 16));
>
>Doubled thing. But we can just drop these and call
>ivb_load_lut_10_max() from higher up instead.

Actually one is GC_MAX and another EXT_GC_MAX. There seem to be 3 set of
registers to be programed here.  Sure, I will use the ivb helper here to optimize this.

>> +
>> +	/*
>> +	 * Program the gc max 2 register to clamp values > 1.0.
>> +	 * ToDo: Extend the ABI to be able to program values
>> +	 * from 3.0 to 7.0
>> +	*/
>> +	if (INTEL_GEN(dev_priv) >= 10 || IS_GEMINILAKE(dev_priv)) {
>> +		I915_WRITE(PREC_PAL_EXT2_GC_MAX(pipe, 0), (1 << 16));
>> +		I915_WRITE(PREC_PAL_EXT2_GC_MAX(pipe, 1), (1 << 16));
>> +		I915_WRITE(PREC_PAL_EXT2_GC_MAX(pipe, 2), (1 << 16));
>> +	}
>> +}
>> +
>> +static void icl_program_fine_segment_lut(const struct intel_crtc_state
>> +					 *crtc_state,
>> +					 struct drm_color_lut *gamma_lut,
>> +					 u32 offset)
>> +{
>> +	struct drm_crtc *crtc = crtc_state->base.crtc;
>> +	struct drm_device *dev = crtc_state->base.crtc->dev;
>> +	struct drm_i915_private *dev_priv = to_i915(dev);
>> +	enum pipe pipe = to_intel_crtc(crtc)->pipe;
>> +	u32 i, word, lut_size = 9;
>> +
>> +	WARN_ON(offset & ~PAL_PREC_MULTI_SEGMENT_INDEX_VALUE_MASK);
>> +
>> +	I915_WRITE(PREC_PAL_MULTI_SEG_INDEX(pipe),
>> +		   (PAL_PREC_AUTO_INCREMENT | offset));
>> +
>> +	if (gamma_lut) {
>> +		struct drm_color_lut *lut =
>> +			(struct drm_color_lut *)gamma_lut;
>> +
>> +		for (i = 0; i < lut_size; i++) {
>> +			/* For Even Index */
>> +			word = (GEN11_GET_LS6BITS_OF_LUT(lut[i].red) << 20) |
>> +				(GEN11_GET_LS6BITS_OF_LUT(lut[i].green) << 10) |
>> +				GEN11_GET_LS6BITS_OF_LUT(lut[i].blue);
>> +
>> +			I915_WRITE(PREC_PAL_MULTI_SEG_DATA(pipe), word);
>> +
>> +			/* For ODD index */
>> +			word = (GEN11_GET_MS10BITS_OF_LUT(lut[i].red) << 20) |
>> +				(GEN11_GET_MS10BITS_OF_LUT(lut[i].green) << 10)
>|
>> +				GEN11_GET_MS10BITS_OF_LUT(lut[i].blue);
>> +
>> +			I915_WRITE(PREC_PAL_MULTI_SEG_DATA(pipe), word);
>> +		}
>> +	}
>> +}
>> +
>> +static void icl_load_gamma_multi_segmented_lut(const struct intel_crtc_state
>> +					       *crtc_state, u32 offset)
>> +{
>> +	const struct drm_property_blob *gamma_mode_blob =
>> +					crtc_state->base.gamma_mode;
>> +	struct drm_color_lut *gamma_lut;
>> +	int ret;
>> +
>> +	if (gamma_mode_blob) {
>> +		struct drm_color_mode_lut *arg = gamma_mode_blob->data;
>> +		u64 __user *props_ptr = (u64 __user *)(unsigned long)(arg->lut);
>> +
>> +		DRM_INFO("Gamma Mode=%s\n", arg->name);
>> +		gamma_lut = kmalloc((sizeof(struct drm_color_lut) * arg->count),
>> +				    GFP_KERNEL);
>> +		ret = copy_from_user(gamma_lut, props_ptr,
>> +				     sizeof(struct drm_color_lut) * arg->count);
>> +	}
>
>What's this doing here?

This is to get the lut values in driver from userspace. The blob passed from user is
struct drm_color_mode_lut {
       /* DRM_MODE_LUT_* */
       __u32 flags;
       /* number of points on the curve */
       __u32 count;
       /* Name of Gamma Mode */
       char name[DRM_PROP_NAME_LEN];
       /* Pointer to Lut elements */
       __u64 lut;
};

The lut values are passed as pointer in "lut", we are copying the same to kernel
memory space here.

>> +
>> +	icl_program_fine_segment_lut(crtc_state, gamma_lut, 0);
>> +	icl_program_coarse_segment_lut(crtc_state, gamma_lut, 0); }
>> +
>>  static void icl_load_luts(const struct intel_crtc_state *crtc_state)
>> {
>>  	if (crtc_state->base.degamma_lut)
>>  		glk_load_degamma_lut(crtc_state);
>>
>> -	if (crtc_state_is_legacy_gamma(crtc_state))
>> +	if (crtc_state_is_legacy_gamma(crtc_state)) {
>>  		i9xx_load_luts(crtc_state);
>> -	else
>> +	} else if (crtc_state->base.gamma_mode_type ==
>> +		   MULTI_SEGMENTED_GAMMA_MODE_12BIT) {
>> +		icl_load_gamma_multi_segmented_lut(crtc_state, 0);
>> +	} else {
>>  		/* ToDo: Add support for multi segment gamma LUT */
>>  		bdw_load_gamma_lut(crtc_state, 0);
>> +	}
>>  }
>>
>>  static void cherryview_load_luts(const struct intel_crtc_state
>> *crtc_state) @@ -1034,10 +1176,20 @@ static int glk_color_check(struct
>intel_crtc_state *crtc_state)
>>  	return 0;
>>  }
>>
>> -static u32 icl_gamma_mode(const struct intel_crtc_state *crtc_state)
>> +static u32 icl_gamma_mode(struct intel_crtc_state *crtc_state)
>>  {
>> +	const struct drm_property_blob *gamma_mode_blob =
>> +					crtc_state->base.gamma_mode;
>> +	struct drm_color_mode_lut *arg;
>>  	u32 gamma_mode = 0;
>>
>> +	if (gamma_mode_blob) {
>> +		arg = gamma_mode_blob->data;
>> +		if (!strcmp(arg->name, "multi-segmented gamma"))
>> +			crtc_state->base.gamma_mode_type =
>> +				MULTI_SEGMENTED_GAMMA_MODE_12BIT;
>> +	}
>
>With the blob_enum this kind of stuff should disappear I think.

I feel keeping 2 separate properties should be good as we can keep the capabilities
immutable. And with the above structure userspace should be able to set any supported
gamma_mode.  Let me know your opinion on the same.

Regards,
Uma Shankar

>> +
>>  	if (crtc_state->base.degamma_lut)
>>  		gamma_mode |= PRE_CSC_GAMMA_ENABLE;
>>
>> @@ -1048,6 +1200,9 @@ static u32 icl_gamma_mode(const struct intel_crtc_state
>*crtc_state)
>>  	if (!crtc_state->base.gamma_lut ||
>>  	    crtc_state_is_legacy_gamma(crtc_state))
>>  		gamma_mode |= GAMMA_MODE_MODE_8BIT;
>> +	else if (crtc_state->base.gamma_mode_type ==
>> +		 MULTI_SEGMENTED_GAMMA_MODE_12BIT)
>> +		gamma_mode |=
>GAMMA_MODE_MODE_12BIT_MULTI_SEGMENTED;
>>  	else
>>  		gamma_mode |= GAMMA_MODE_MODE_10BIT;
>>
>> diff --git a/include/drm/drm_crtc.h b/include/drm/drm_crtc.h index
>> bc8a2e7..a8d0b4c 100644
>> --- a/include/drm/drm_crtc.h
>> +++ b/include/drm/drm_crtc.h
>> @@ -262,6 +262,9 @@ struct drm_crtc_state {
>>  	 */
>>  	struct drm_property_blob *gamma_mode;
>>
>> +	/* Gamma mode type programmed on the pipe */
>> +	u32 gamma_mode_type;
>> +
>>  	/**
>>  	 * @degamma_lut:
>>  	 *
>> --
>> 1.9.1
>>
>> _______________________________________________
>> Intel-gfx mailing list
>> Intel-gfx at lists.freedesktop.org
>> https://lists.freedesktop.org/mailman/listinfo/intel-gfx
>
>--
>Ville Syrjälä
>Intel


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