[Intel-gfx] [v4 2/2] drm/i915/icl: Enable Plane Input CSC for YUV to RGB Conversion

Shankar, Uma uma.shankar at intel.com
Fri Oct 26 09:24:07 UTC 2018



>-----Original Message-----
>From: Maarten Lankhorst [mailto:maarten.lankhorst at linux.intel.com]
>Sent: Friday, October 26, 2018 2:11 PM
>To: Roper, Matthew D <matthew.d.roper at intel.com>; Shankar, Uma
><uma.shankar at intel.com>
>Cc: intel-gfx at lists.freedesktop.org; Syrjala, Ville <ville.syrjala at intel.com>;
>Lankhorst, Maarten <maarten.lankhorst at intel.com>
>Subject: Re: [Intel-gfx] [v4 2/2] drm/i915/icl: Enable Plane Input CSC for YUV to
>RGB Conversion
>
>Op 26-10-18 om 00:11 schreef Matt Roper:
>> On Fri, Oct 26, 2018 at 03:33:38AM +0530, Uma Shankar wrote:
>>> Plane input CSC needs to be enabled to convert frambuffers from YUV
>>> to RGB. This is needed for bottom 3 planes on ICL, rest of the planes
>>> have hardcoded conversion and taken care by the legacy code.
>>>
>>> This patch defines the co-efficient values for YUV to RGB conversion
>>> in BT709 and BT601 formats. It programs the coefficients and enables
>>> the plane input csc unit in hardware.
>>>
>>> Note: This is currently untested and floated to get an early feedback
>>> on the design and implementation for this feature. In parallel, I
>>> will test this on actual ICL hardware and confirm with planar
>>> formats.
>>>
>>> v2: Addressed Maarten's and Ville's review comments and added the
>>> coefficients in a 2D array instead of independent Macros.
>>>
>>> v3: Added individual coefficient matrix (9 values) instead of 6
>>> register values as per Maarten's comment. Also addresed a shift issue
>>> with B channel coefficient.
>>>
>>> v4: Added support for Limited Range Color Handling
>>>
>>> Signed-off-by: Uma Shankar <uma.shankar at intel.com>
>>> ---
>>>  drivers/gpu/drm/i915/intel_color.c   | 79
>++++++++++++++++++++++++++++++++++++
>>>  drivers/gpu/drm/i915/intel_display.c | 23 ++++++++---
>>>  drivers/gpu/drm/i915/intel_drv.h     |  2 +
>>>  3 files changed, 98 insertions(+), 6 deletions(-)
>>>
>>> diff --git a/drivers/gpu/drm/i915/intel_color.c
>>> b/drivers/gpu/drm/i915/intel_color.c
>>> index 5127da2..3a52d92 100644
>>> --- a/drivers/gpu/drm/i915/intel_color.c
>>> +++ b/drivers/gpu/drm/i915/intel_color.c
>>> @@ -57,6 +57,15 @@
>>>  #define CSC_RGB_TO_YUV_RV_GV 0xbce89ad8  #define
>CSC_RGB_TO_YUV_BV
>>> 0x1e080000
>>>
>>> +#define  ROFF(x)          (((x) & 0xffff) << 16)
>>> +#define  GOFF(x)          (((x) & 0xffff) << 0)
>>> +#define  BOFF(x)          (((x) & 0xffff) << 16)
>>> +
>>> +/* Preoffset values for YUV to RGB Conversion */
>>> +#define PREOFF_YUV_TO_RGB_HI		0x800
>>> +#define PREOFF_YUV_TO_RGB_ME		0xF00
>>> +#define PREOFF_YUV_TO_RGB_LO		0x800
>> Doesn't bit #12 need to be set for each of these values (0x1800,
>> 0x1F00, 0x1800)?  At least that's what I came up with based on the
>> assumption that input CSC is programmed the same way as pipe CSC, but
>> I might be overlooking or miscalculating something.
>>
>> The pipe CSC page gives an example of converting YUV to RGB with a
>> table that matches your csc matrix below, and a note "Program the CSC
>> Pre-Offsets to -1/2, -1/16, and -1/2."
>>
>> The bspec indicates the register values here are 13-bits (12:0 in the
>> register dword) and are 2's complement fractions allowing values
>> between
>> -1 and 1 (exclusive).  So I take that to mean:
>>
>>     1/2                     = 0 1000 0000 0000
>>     -1/2 (one's complement) = 1 0111 1111 1111
>>     -1/2 (two's complement) = 1 1000 0000 0000 = 0x1800
>>
>> and
>>
>>     1/16                     = 0 0001 0000 0000
>>     -1/16 (one's complement) = 1 1110 1111 1111
>>     -1/16 (two's complement) = 1 1111 0000 0000 = 0x1F00
>>
>> Anyway, it would probably be good to give a comment indicating what
>> the human-readable values you're using are supposed to be and an
>> indication of how the register is programmed to represent those values.

Yes, You are right here. Will correct it. Thanks Matt !!

>> Matt
>>
>>> +
>>>  /*
>>>   * Extract the CSC coefficient from a CTM coefficient (in U32.32 fixed point
>>>   * format). This macro takes the coefficient we want transformed and
>>> the @@ -643,6 +652,76 @@ int intel_color_check(struct drm_crtc *crtc,
>>>  	return -EINVAL;
>>>  }
>>>
>>> +void icl_program_input_csc_coeff(const struct intel_crtc_state *crtc_state,
>>> +				 const struct intel_plane_state *plane_state) {
>>> +	struct drm_i915_private *dev_priv =
>>> +		to_i915(plane_state->base.plane->dev);
>>> +	struct intel_crtc *crtc = to_intel_crtc(crtc_state->base.crtc);
>>> +	enum pipe pipe = crtc->pipe;
>>> +	struct intel_plane *intel_plane =
>>> +		to_intel_plane(plane_state->base.plane);
>>> +	enum plane_id plane = intel_plane->id;
>>> +
>>> +	static const u16 input_csc_matrix[][9] = {
>>> +		/* BT.601 full range YCbCr -> full range RGB */
>>> +		[DRM_COLOR_YCBCR_BT601] = {
>>> +			0x7AF8, 7800, 0x0,
>>> +			0x8B28, 7800, 0x9AC0,
>>> +			0x0, 7800, 0x7DD8,
>>> +		},
>>> +		/* BT.709 full range YCbCr -> full range RGB */
>>> +		[DRM_COLOR_YCBCR_BT709] = {
>>> +			0x7C98, 7800, 0x0,
>>> +			0x9EF8, 7800, 0xABF8,
>>> +			0x0, 0x7800,  0x7ED8,
>>> +		},
>>> +	};
>>> +
>>> +	/* Matrix for Limited Range to Full Range Conversion */
>>> +	static const u16 input_csc_matrix_lr[][9] = {
>>> +		/* BT.601 Limted range YCbCr -> full range RGB */
>>> +		[DRM_COLOR_YCBCR_BT601] = {
>>> +			0x7CC8, 7950, 0x0,
>>> +			0x8CB8, 7918, 0x9C40,
>>> +			0x0, 7918, 0x7FC8,
>I think you forgot to add 0x to the second value, resulting in part hex, part
>numeric.

Oh :( , Yes my bad. Will rectify the error. Thanks

Regards,
Uma Shankar

>~Maarten
>>> +		},
>>> +		/* BT.709 Limited range YCbCr -> full range RGB */
>>> +		[DRM_COLOR_YCBCR_BT709] = {
>>> +			0x7EA8, 7950, 0x0,
>>> +			0x8888, 7918, 0xADA8,
>>> +			0x0, 0x7918,  0x6870,
>>> +		},
>>> +	};
>>> +	const u16 *csc;
>>> +
>>> +	if (plane_state->base.color_range ==
>DRM_COLOR_YCBCR_FULL_RANGE)
>>> +		csc = input_csc_matrix[plane_state->base.color_encoding];
>>> +	else
>>> +		csc = input_csc_matrix_lr[plane_state->base.color_encoding];
>>> +
>>> +	I915_WRITE(PLANE_INPUT_CSC_COEFF_REG(pipe, plane, 0),
>ROFF(csc[0]) |
>>> +		   GOFF(csc[1]));
>>> +	I915_WRITE(PLANE_INPUT_CSC_COEFF_REG(pipe, plane, 1),
>BOFF(csc[2]));
>>> +	I915_WRITE(PLANE_INPUT_CSC_COEFF_REG(pipe, plane, 2),
>ROFF(csc[3]) |
>>> +		   GOFF(csc[4]));
>>> +	I915_WRITE(PLANE_INPUT_CSC_COEFF_REG(pipe, plane, 3),
>BOFF(csc[5]));
>>> +	I915_WRITE(PLANE_INPUT_CSC_COEFF_REG(pipe, plane, 4),
>ROFF(csc[6]) |
>>> +		   GOFF(csc[7]));
>>> +	I915_WRITE(PLANE_INPUT_CSC_COEFF_REG(pipe, plane, 5),
>>> +BOFF(csc[8]));
>>> +
>>> +	I915_WRITE(PLANE_INPUT_CSC_PREOFF_REG(pipe, plane, 0),
>>> +		   PREOFF_YUV_TO_RGB_HI);
>>> +	I915_WRITE(PLANE_INPUT_CSC_PREOFF_REG(pipe, plane, 1),
>>> +		   PREOFF_YUV_TO_RGB_ME);
>>> +	I915_WRITE(PLANE_INPUT_CSC_PREOFF_REG(pipe, plane, 2),
>>> +		   PREOFF_YUV_TO_RGB_LO);
>>> +
>>> +	I915_WRITE(PLANE_INPUT_CSC_POSTOFF_REG(pipe, plane, 0), 0x0);
>>> +	I915_WRITE(PLANE_INPUT_CSC_POSTOFF_REG(pipe, plane, 1), 0x0);
>>> +	I915_WRITE(PLANE_INPUT_CSC_POSTOFF_REG(pipe, plane, 2), 0x0); }
>>> +
>>>  void intel_color_init(struct drm_crtc *crtc)  {
>>>  	struct drm_i915_private *dev_priv = to_i915(crtc->dev); diff --git
>>> a/drivers/gpu/drm/i915/intel_display.c
>>> b/drivers/gpu/drm/i915/intel_display.c
>>> index fe045ab..d16a064 100644
>>> --- a/drivers/gpu/drm/i915/intel_display.c
>>> +++ b/drivers/gpu/drm/i915/intel_display.c
>>> @@ -3666,6 +3666,7 @@ u32 glk_plane_color_ctl(const struct
>intel_crtc_state *crtc_state,
>>>  	struct drm_i915_private *dev_priv =
>>>  		to_i915(plane_state->base.plane->dev);
>>>  	const struct drm_framebuffer *fb = plane_state->base.fb;
>>> +	struct intel_plane *plane =
>>> +to_intel_plane(plane_state->base.plane);
>>>  	u32 plane_color_ctl = 0;
>>>
>>>  	if (INTEL_GEN(dev_priv) < 11) {
>>> @@ -3676,13 +3677,23 @@ u32 glk_plane_color_ctl(const struct
>intel_crtc_state *crtc_state,
>>>  	plane_color_ctl |= glk_plane_color_ctl_alpha(plane_state);
>>>
>>>  	if (fb->format->is_yuv) {
>>> -		if (plane_state->base.color_encoding ==
>DRM_COLOR_YCBCR_BT709)
>>> -			plane_color_ctl |=
>PLANE_COLOR_CSC_MODE_YUV709_TO_RGB709;
>>> -		else
>>> -			plane_color_ctl |=
>PLANE_COLOR_CSC_MODE_YUV601_TO_RGB709;
>>> +		if (!icl_is_hdr_plane(plane)) {
>>> +			if (plane_state->base.color_encoding ==
>>> +					DRM_COLOR_YCBCR_BT709)
>>> +				plane_color_ctl |=
>>> +
>	PLANE_COLOR_CSC_MODE_YUV709_TO_RGB709;
>>> +			else
>>> +				plane_color_ctl |=
>>> +
>	PLANE_COLOR_CSC_MODE_YUV601_TO_RGB709;
>>>
>>> -		if (plane_state->base.color_range ==
>DRM_COLOR_YCBCR_FULL_RANGE)
>>> -			plane_color_ctl |=
>PLANE_COLOR_YUV_RANGE_CORRECTION_DISABLE;
>>> +			if (plane_state->base.color_range ==
>>> +					DRM_COLOR_YCBCR_FULL_RANGE)
>>> +				plane_color_ctl |=
>>> +
>	PLANE_COLOR_YUV_RANGE_CORRECTION_DISABLE;
>>> +		} else {
>>> +			icl_program_input_csc_coeff(crtc_state, plane_state);
>>> +			plane_color_ctl |= PLANE_COLOR_INPUT_CSC_ENABLE;
>>> +		}
>>>  	}
>>>
>>>  	return plane_color_ctl;
>>> diff --git a/drivers/gpu/drm/i915/intel_drv.h
>>> b/drivers/gpu/drm/i915/intel_drv.h
>>> index db24308..bd9e946 100644
>>> --- a/drivers/gpu/drm/i915/intel_drv.h
>>> +++ b/drivers/gpu/drm/i915/intel_drv.h
>>> @@ -2285,6 +2285,8 @@ int intel_plane_atomic_check_with_state(const
>>> struct intel_crtc_state *old_crtc_  int intel_color_check(struct
>>> drm_crtc *crtc, struct drm_crtc_state *state);  void
>>> intel_color_set_csc(struct drm_crtc_state *crtc_state);  void
>>> intel_color_load_luts(struct drm_crtc_state *crtc_state);
>>> +void icl_program_input_csc_coeff(const struct intel_crtc_state *crtc_state,
>>> +				 const struct intel_plane_state *plane_state);
>>>
>>>  /* intel_lspcon.c */
>>>  bool lspcon_init(struct intel_digital_port *intel_dig_port);
>>> --
>>> 1.9.1
>>>
>>> _______________________________________________
>>> Intel-gfx mailing list
>>> Intel-gfx at lists.freedesktop.org
>>> https://lists.freedesktop.org/mailman/listinfo/intel-gfx
>



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