[Intel-gfx] [PATCH 11/16] drm/i915: Add pipe level Gamma correction for CHV/BSW

Matt Roper matthew.d.roper at intel.com
Mon Jul 20 17:03:32 PDT 2015


On Wed, Jul 15, 2015 at 06:39:35PM +0530, Kausal Malladi wrote:
> CHV/BSW platform supports various Gamma correction modes, which are:
> 1. Legacy 8-bit mode
> 2. 10-bit CGM (Color Gamut Mapping) mode
> 
> This patch does the following:
> 1. Adds the core function to program Gamma correction values for CHV/BSW
>    platform
> 2. Adds Gamma correction macros/defines
> 
> Signed-off-by: Shashank Sharma <shashank.sharma at intel.com>
> Signed-off-by: Kausal Malladi <Kausal.Malladi at intel.com>
> ---
>  drivers/gpu/drm/i915/i915_reg.h            |  12 +++
>  drivers/gpu/drm/i915/intel_color_manager.c | 149 +++++++++++++++++++++++++++++
>  drivers/gpu/drm/i915/intel_color_manager.h |  20 ++++
>  drivers/gpu/drm/i915/intel_display.c       |   3 +
>  drivers/gpu/drm/i915/intel_drv.h           |   2 +
>  5 files changed, 186 insertions(+)
> 
> diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h
> index 059de0f..4ec2e4f 100644
> --- a/drivers/gpu/drm/i915/i915_reg.h
> +++ b/drivers/gpu/drm/i915/i915_reg.h
> @@ -7906,4 +7906,16 @@ enum skl_disp_power_wells {
>  #define _PALETTE_A (dev_priv->info.display_mmio_offset + 0xa000)
>  #define _PALETTE_B (dev_priv->info.display_mmio_offset + 0xa800)
>  
> +/* Color Management */
> +#define PIPEA_CGM_CONTROL			(VLV_DISPLAY_BASE + 0x67A00)
> +#define PIPEB_CGM_CONTROL			(VLV_DISPLAY_BASE + 0x69A00)
> +#define PIPEC_CGM_CONTROL			(VLV_DISPLAY_BASE + 0x6BA00)
> +#define PIPEA_CGM_GAMMA				(VLV_DISPLAY_BASE + 0x67000)
> +#define PIPEB_CGM_GAMMA				(VLV_DISPLAY_BASE + 0x69000)
> +#define PIPEC_CGM_GAMMA				(VLV_DISPLAY_BASE + 0x6B000)
> +#define _PIPE_CGM_CONTROL(pipe) \
> +	(_PIPE3(pipe, PIPEA_CGM_CONTROL, PIPEB_CGM_CONTROL, PIPEC_CGM_CONTROL))
> +#define _PIPE_GAMMA_BASE(pipe) \
> +	(_PIPE3(pipe, PIPEA_CGM_GAMMA, PIPEB_CGM_GAMMA, PIPEC_CGM_GAMMA))
> +
>  #endif /* _I915_REG_H_ */
> diff --git a/drivers/gpu/drm/i915/intel_color_manager.c b/drivers/gpu/drm/i915/intel_color_manager.c
> index 70c0d42..7e9e934 100644
> --- a/drivers/gpu/drm/i915/intel_color_manager.c
> +++ b/drivers/gpu/drm/i915/intel_color_manager.c
> @@ -27,6 +27,155 @@
>  
>  #include "intel_color_manager.h"
>  
> +int chv_set_gamma(struct drm_device *dev, struct drm_property_blob *blob,
> +		  struct drm_crtc *crtc)
> +{
> +	struct drm_palette *gamma_data;
> +	struct drm_i915_private *dev_priv = dev->dev_private;
> +	struct drm_mode_config *config = &dev->mode_config;
> +	u32 cgm_control_reg = 0;
> +	u32 cgm_gamma_reg = 0;
> +	enum pipe pipe;
> +	u32 red, green, blue;
> +	u8 red_int, blue_int, green_int;
> +	u16 red_fract, green_fract, blue_fract;
> +	u32 count = 0;
> +	struct drm_r32g32b32 *correction_values = NULL;
> +	u32 num_samples;
> +	u32 word;
> +	int ret = 0, length, flag = 0;
> +
> +	if (!blob) {
> +		DRM_ERROR("NULL Blob\n");
> +		return -EINVAL;
> +	}
> +
> +	gamma_data = (struct drm_palette *)blob->data;
> +
> +	if (gamma_data->version != CHV_GAMMA_DATA_STRUCT_VERSION) {
> +		DRM_ERROR("Invalid Gamma Data struct version\n");
> +		return -EINVAL;
> +	}
> +
> +	pipe = to_intel_crtc(crtc)->pipe;
> +	num_samples = gamma_data->num_samples;
> +	length = num_samples * sizeof(struct drm_r32g32b32);
> +
> +	if (num_samples == 0) {
> +
> +		/* Disable Gamma functionality on Pipe - CGM Block */
> +		cgm_control_reg = I915_READ(_PIPE_CGM_CONTROL(pipe));
> +		cgm_control_reg &= ~CGM_GAMMA_EN;
> +		I915_WRITE(_PIPE_CGM_CONTROL(pipe), cgm_control_reg);
> +
> +		DRM_DEBUG_DRIVER("Gamma disabled on Pipe %c\n",
> +				pipe_name(pipe));
> +		ret = 0;
> +	} else if (num_samples == CHV_10BIT_GAMMA_MAX_VALS ||
> +			num_samples == CHV_8BIT_GAMMA_MAX_VALS) {
> +		cgm_gamma_reg = _PIPE_GAMMA_BASE(pipe);
> +
> +		count = 0;
> +		correction_values = (struct drm_r32g32b32 *)&gamma_data->lut;
> +		while (count < num_samples) {
> +			blue = correction_values[count].b32;
> +			green = correction_values[count].g32;
> +			red = correction_values[count].r32;
> +
> +			blue_int = _GAMMA_INT_PART(blue);
> +			if (blue_int > GAMMA_INT_MAX)
> +				blue = CHV_MAX_GAMMA;
> +			green_int = _GAMMA_INT_PART(green);
> +			if (green_int > GAMMA_INT_MAX)
> +				green = CHV_MAX_GAMMA;
> +			red_int = _GAMMA_INT_PART(red);
> +			if (red_int > GAMMA_INT_MAX)
> +				red = CHV_MAX_GAMMA;
> +
> +			blue_fract = _GAMMA_FRACT_PART(blue);
> +			green_fract = _GAMMA_FRACT_PART(green);
> +			red_fract = _GAMMA_FRACT_PART(red);
> +
> +			blue_fract >>= CHV_10BIT_GAMMA_MSB_SHIFT;
> +			green_fract >>= CHV_10BIT_GAMMA_MSB_SHIFT;
> +			red_fract >>= CHV_10BIT_GAMMA_MSB_SHIFT;
> +
> +			/* Green (25:16) and Blue (9:0) to be written */
> +			word = green_fract;
> +			word <<= CHV_GAMMA_SHIFT_GREEN;
> +			word = word | blue_fract;
> +			I915_WRITE(cgm_gamma_reg, word);
> +			cgm_gamma_reg += 4;
> +
> +			/* Red (9:0) to be written */
> +			word = red_fract;
> +			I915_WRITE(cgm_gamma_reg, word);
> +
> +			cgm_gamma_reg += 4;
> +			count++;
> +
> +			/*
> +			 * On CHV, the best supported Gamma capability is
> +			 * CGM block, that takes 257 samples.
> +			 * If user gives 256 samples (legacy mode), then
> +			 * duplicate the 256th value to 257th.
> +			 * "flag" is used to make sure it happens only once
> +			 */
> +			if (num_samples == CHV_8BIT_GAMMA_MAX_VALS
> +					&& count == CHV_8BIT_GAMMA_MAX_VALS
> +					&& !flag) {
> +				count--;
> +				flag = 1;
> +			}
> +		}
> +
> +		DRM_DEBUG_DRIVER("Gamma LUT loaded successfully for Pipe %c\n",
> +			pipe_name(pipe));
> +
> +		/* Enable (CGM) Gamma on Pipe */
> +		I915_WRITE(_PIPE_CGM_CONTROL(pipe),
> +			I915_READ(_PIPE_CGM_CONTROL(pipe))
> +			| CGM_GAMMA_EN);
> +		DRM_DEBUG_DRIVER("CGM Gamma enabled on Pipe %c\n",
> +				pipe_name(pipe));
> +
> +		ret = 0;
> +	} else {
> +		DRM_ERROR("Invalid number of samples for Gamma LUT\n");
> +		return -EINVAL;
> +	}
> +
> +	ret = drm_property_replace_global_blob(dev, &blob, length,
> +			(void *) gamma_data, &crtc->base,
> +			config->prop_palette_after_ctm);

Is this supposed to be here?  This function seems to be for just
programming the hardware with the contents of the current blob.  I'm not
sure I understand why we try to alter the blob itself at the end of
that.  I see the same in your degamma patch.

> +
> +	if (ret) {
> +		DRM_ERROR("Error updating Gamma blob\n");
> +		return -EFAULT;
> +	}
> +
> +	return ret;
> +}
> +
> +void intel_color_manager_crtc_commit(struct drm_device *dev,
> +		struct drm_crtc_state *crtc_state)
> +{
> +	struct drm_property_blob *blob;
> +	struct drm_crtc *crtc = crtc_state->crtc;
> +	int ret = 0;
> +
> +	if (IS_CHERRYVIEW(dev)) {
> +		blob = crtc_state->palette_after_ctm_blob;
> +		if (blob) {
> +			ret = chv_set_gamma(dev, blob, crtc);
> +			if (!ret)
> +				DRM_DEBUG_DRIVER(
> +					"Gamma registers Commit success!\n");
> +		}
> +
> +	}
> +}
> +
>  int intel_color_manager_set_pipe_gamma(struct drm_device *dev,
>  		struct drm_crtc_state *crtc_state,
>  		struct drm_mode_object *obj, uint32_t blob_id)
> diff --git a/drivers/gpu/drm/i915/intel_color_manager.h b/drivers/gpu/drm/i915/intel_color_manager.h
> index 51aeb91..8bbac20 100644
> --- a/drivers/gpu/drm/i915/intel_color_manager.h
> +++ b/drivers/gpu/drm/i915/intel_color_manager.h
> @@ -28,6 +28,26 @@
>  #include <drm/drm_crtc_helper.h>
>  #include "i915_drv.h"
>  
> +#define _GAMMA_INT_PART(value)			(value >> GAMMA_INT_SHIFT)
> +#define _GAMMA_FRACT_PART(value)		(value >> GAMMA_FRACT_SHIFT)
> +
>  #define CHV_PALETTE_STRUCT_VERSION		1
>  #define CHV_DEGAMMA_MAX_VALS			65
>  #define CHV_10BIT_GAMMA_MAX_VALS		257
> +
> +/* Gamma correction */
> +#define CHV_GAMMA_DATA_STRUCT_VERSION		1
> +#define CHV_10BIT_GAMMA_MAX_VALS		257
> +#define CHV_8BIT_GAMMA_MAX_VALS			256
> +#define CHV_10BIT_GAMMA_MSB_SHIFT		6
> +#define CHV_GAMMA_SHIFT_GREEN			16
> +/* Gamma values are u8.24 format */
> +#define GAMMA_INT_SHIFT				24
> +#define GAMMA_FRACT_SHIFT			8
> +/* Max int value for Gamma is 1 */
> +#define GAMMA_INT_MAX				1
> +/* Max value for Gamma on CHV */
> +#define CHV_MAX_GAMMA				0x10000
> +
> +/* CHV CGM Block */
> +#define CGM_GAMMA_EN				(1 << 2)
> diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
> index 11d491e..9e994fc 100644
> --- a/drivers/gpu/drm/i915/intel_display.c
> +++ b/drivers/gpu/drm/i915/intel_display.c
> @@ -13773,6 +13773,9 @@ static void intel_begin_crtc_commit(struct drm_crtc *crtc)
>  
>  	if (!needs_modeset(crtc->state) && INTEL_INFO(dev)->gen >= 9)
>  		skl_detach_scalers(intel_crtc);
> +
> +	if (!needs_modeset(crtc->state))
> +		intel_color_manager_crtc_commit(dev, crtc->state);

It's not immediately clear to me why this is only for the
'!needs_modeset' case.  Does color management get setup somewhere else
in cases where a display update does involve a modeset?


Matt

>  }
>  
>  static void intel_finish_crtc_commit(struct drm_crtc *crtc)
> diff --git a/drivers/gpu/drm/i915/intel_drv.h b/drivers/gpu/drm/i915/intel_drv.h
> index 45c42f0..d8d8326 100644
> --- a/drivers/gpu/drm/i915/intel_drv.h
> +++ b/drivers/gpu/drm/i915/intel_drv.h
> @@ -1456,5 +1456,7 @@ void intel_attach_color_properties_to_crtc(struct drm_device *dev,
>  int intel_color_manager_set_pipe_gamma(struct drm_device *dev,
>  		struct drm_crtc_state *crtc_state,
>  		struct drm_mode_object *obj, uint32_t blob_id);
> +void intel_color_manager_crtc_commit(struct drm_device *dev,
> +		struct drm_crtc_state *crtc_state);
>  
>  #endif /* __INTEL_DRV_H__ */
> -- 
> 2.4.5
> 

-- 
Matt Roper
Graphics Software Engineer
IoTG Platform Enabling & Development
Intel Corporation
(916) 356-2795


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