[PATCH 10/12] drm/i915: Add DeGamma correction for CHV/BSW

Kausal Malladi Kausal.Malladi at intel.com
Thu Jul 2 20:31:45 PDT 2015


CHV/BSW supports DeGamma color correction feature, which linearizes all
the non-linear color values. This will be applied before Color
Transformation.

This patch does the following:
1. Adds the core function to program DeGamma correction values for
   CHV/BSW platform
2. Adds DeGamma 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            |   4 ++
 drivers/gpu/drm/i915/intel_atomic.c        |   2 +
 drivers/gpu/drm/i915/intel_color_manager.c | 110 +++++++++++++++++++++++++++++
 drivers/gpu/drm/i915/intel_color_manager.h |   5 ++
 drivers/gpu/drm/i915/intel_drv.h           |   2 +
 5 files changed, 123 insertions(+)

diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h
index 36672e7..58a1414 100644
--- a/drivers/gpu/drm/i915/i915_reg.h
+++ b/drivers/gpu/drm/i915/i915_reg.h
@@ -7903,11 +7903,15 @@ enum skl_disp_power_wells {
 /* Color Management */
 #define PIPEA_CGM_CONTROL			(VLV_DISPLAY_BASE + 0x67A00)
 #define PIPEA_CGM_GAMMA_MIN			(VLV_DISPLAY_BASE + 0x67000)
+#define PIPEA_CGM_DEGAMMA_MIN			(VLV_DISPLAY_BASE + 0x66000)
 #define CGM_OFFSET				0x2000
 #define GAMMA_OFFSET				0x2000
+#define DEGAMMA_OFFSET				0x2000
 #define _PIPE_CGM_CONTROL(pipe) \
 	(PIPEA_CGM_CONTROL + (pipe * CGM_OFFSET))
 #define _PIPE_GAMMA_BASE(pipe) \
 	(PIPEA_CGM_GAMMA_MIN + (pipe * GAMMA_OFFSET))
+#define _PIPE_DEGAMMA_BASE(pipe) \
+	(PIPEA_CGM_DEGAMMA_MIN + (pipe * DEGAMMA_OFFSET))
 
 #endif /* _I915_REG_H_ */
diff --git a/drivers/gpu/drm/i915/intel_atomic.c b/drivers/gpu/drm/i915/intel_atomic.c
index 21f0ac2..570af9d 100644
--- a/drivers/gpu/drm/i915/intel_atomic.c
+++ b/drivers/gpu/drm/i915/intel_atomic.c
@@ -478,6 +478,8 @@ int intel_crtc_atomic_set_property(struct drm_crtc *crtc,
 
 	if (property == config->prop_palette_after_ctm)
 		return intel_color_manager_set_gamma(dev, &crtc->base, val);
+	if (property == config->prop_palette_before_ctm)
+		return intel_color_manager_set_degamma(dev, &crtc->base, val);
 
 	DRM_DEBUG_KMS("Unknown crtc property '%s'\n", property->name);
 	return -EINVAL;
diff --git a/drivers/gpu/drm/i915/intel_color_manager.c b/drivers/gpu/drm/i915/intel_color_manager.c
index 84cc3e47..21c499f 100644
--- a/drivers/gpu/drm/i915/intel_color_manager.c
+++ b/drivers/gpu/drm/i915/intel_color_manager.c
@@ -27,6 +27,105 @@
 
 #include "intel_color_manager.h"
 
+int chv_set_degamma(struct drm_device *dev, uint32_t blob_id,
+		  struct drm_crtc *crtc)
+{
+	struct drm_palette *degamma_data;
+	struct drm_i915_private *dev_priv = dev->dev_private;
+	struct drm_property_blob *blob;
+	struct drm_mode_config *config = &dev->mode_config;
+	u32 cgm_control_reg = 0;
+	u32 cgm_degamma_reg = 0;
+	enum pipe pipe;
+	u16 red, green, blue;
+	u32 count = 0;
+	struct drm_r32g32b32 *correction_values = NULL;
+	u32 num_samples;
+	u32 word;
+	int ret = 0, length;
+
+	blob = drm_property_lookup_blob(dev, blob_id);
+	if (!blob) {
+		DRM_ERROR("Invalid Blob ID\n");
+		return -EINVAL;
+	}
+
+	degamma_data = (struct drm_palette *)blob->data;
+
+	if (degamma_data->version != CHV_DEGAMMA_DATA_STRUCT_VERSION) {
+		DRM_ERROR("Invalid DeGamma Data struct version\n");
+		return -EINVAL;
+	}
+
+	pipe = to_intel_crtc(crtc)->pipe;
+	num_samples = degamma_data->palette_num_samples;
+	length = num_samples * sizeof(struct drm_r32g32b32);
+
+	if (num_samples == 0) {
+
+		/* Disable DeGamma functionality on Pipe - CGM Block */
+		cgm_control_reg = I915_READ(_PIPE_CGM_CONTROL(pipe));
+		cgm_control_reg &= ~CGM_DEGAMMA_EN;
+		I915_WRITE(_PIPE_CGM_CONTROL(pipe), cgm_control_reg);
+
+		DRM_DEBUG_DRIVER("DeGamma disabled on Pipe %c\n",
+				pipe_name(pipe));
+		ret = 0;
+	} else if (num_samples == CHV_DEGAMMA_MAX_VALS) {
+		cgm_degamma_reg = _PIPE_DEGAMMA_BASE(pipe);
+
+		count = 0;
+		correction_values =
+			(struct drm_r32g32b32 *)&degamma_data->palette_lut;
+		while (count < CHV_DEGAMMA_MAX_VALS) {
+			blue = correction_values[count].b32;
+			green = correction_values[count].g32;
+			red = correction_values[count].r32;
+
+			blue = blue >> CHV_DEGAMMA_MSB_SHIFT;
+			green = green >> CHV_DEGAMMA_MSB_SHIFT;
+			red = red >> CHV_DEGAMMA_MSB_SHIFT;
+
+			/* Green (29:16) and Blue (13:0) in DWORD1 */
+			word = (green << CHV_DEGAMMA_GREEN_SHIFT) | blue;
+			I915_WRITE(cgm_degamma_reg, word);
+
+			cgm_degamma_reg += 4;
+
+			/* Red (13:0) to be written to DWORD2 */
+			word = red;
+			I915_WRITE(cgm_degamma_reg, word);
+
+			cgm_degamma_reg += 4;
+			count++;
+		}
+
+		DRM_DEBUG_DRIVER("DeGamma LUT loaded for Pipe %c\n",
+				pipe_name(pipe));
+
+		/* Enable DeGamma on Pipe */
+		I915_WRITE(_PIPE_CGM_CONTROL(pipe),
+			I915_READ(_PIPE_CGM_CONTROL(pipe)) | CGM_DEGAMMA_EN);
+
+		DRM_DEBUG_DRIVER("DeGamma correction enabled on Pipe %c\n",
+				pipe_name(pipe));
+		ret = 0;
+	} else {
+		DRM_ERROR("Invalid number of samples for DeGamma LUT\n");
+		return -EINVAL;
+	}
+
+	ret = drm_property_replace_global_blob(dev, &blob, length,
+			(void *) degamma_data, &crtc->base,
+			config->prop_palette_before_ctm);
+
+	if (ret) {
+		DRM_ERROR("Error updating DeGamma blob\n");
+		return -EFAULT;
+	}
+
+	return ret;
+}
 int chv_set_gamma(struct drm_device *dev, uint32_t blob_id,
 		  struct drm_crtc *crtc)
 {
@@ -181,6 +280,17 @@ int intel_color_manager_set_gamma(struct drm_device *dev,
 	return -EINVAL;
 }
 
+int intel_color_manager_set_degamma(struct drm_device *dev,
+		struct drm_mode_object *obj, uint32_t blob_id)
+{
+	struct drm_crtc *crtc = obj_to_crtc(obj);
+
+	if (IS_CHERRYVIEW(dev))
+		return chv_set_degamma(dev, blob_id, crtc);
+
+	return -EINVAL;
+}
+
 int get_chv_pipe_capabilities(struct drm_device *dev,
 		struct drm_color_caps *color_caps, struct drm_crtc *crtc)
 {
diff --git a/drivers/gpu/drm/i915/intel_color_manager.h b/drivers/gpu/drm/i915/intel_color_manager.h
index d83567a..64468c1 100644
--- a/drivers/gpu/drm/i915/intel_color_manager.h
+++ b/drivers/gpu/drm/i915/intel_color_manager.h
@@ -32,6 +32,7 @@
 #define CHV_CTM_STRUCT_VERSION			1
 #define CHV_PLATFORM_STRUCT_VERSION		1
 #define CHV_GAMMA_DATA_STRUCT_VERSION		1
+#define CHV_DEGAMMA_DATA_STRUCT_VERSION		1
 
 #define CHV_MAX_PALETTE_CAPS_BEFORE_CTM		1
 #define CHV_MAX_PALETTE_CAPS_AFTER_CTM		2
@@ -51,6 +52,9 @@
 #define CHV_10BIT_GAMMA_MSB_SHIFT		6
 #define CHV_GAMMA_SHIFT_GREEN			16
 
+#define CHV_DEGAMMA_MSB_SHIFT			2
+#define CHV_DEGAMMA_GREEN_SHIFT			16
+
 #define CHV_CSC_COEFF_MAX_PRECISION		12
 #define CHV_CSC_COEFF_MAX_INT			7
 #define CHV_CSC_COEFF_MIN_INT			-7
@@ -58,3 +62,4 @@
 /* CHV CGM Block */
 /* Bit 2 to be enabled in CGM block for CHV */
 #define CGM_GAMMA_EN				4
+#define CGM_DEGAMMA_EN				1
diff --git a/drivers/gpu/drm/i915/intel_drv.h b/drivers/gpu/drm/i915/intel_drv.h
index a7aaadf..f47d9d6 100644
--- a/drivers/gpu/drm/i915/intel_drv.h
+++ b/drivers/gpu/drm/i915/intel_drv.h
@@ -1455,5 +1455,7 @@ void intel_color_manager_attach(struct drm_device *dev,
 		struct drm_mode_object *mode_obj);
 int intel_color_manager_set_gamma(struct drm_device *dev,
 		struct drm_mode_object *obj, uint32_t blob_id);
+int intel_color_manager_set_degamma(struct drm_device *dev,
+		struct drm_mode_object *obj, uint32_t blob_id);
 
 #endif /* __INTEL_DRV_H__ */
-- 
2.4.5



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