[PATCH 15/23] drm/i915: CHV: Pipe level Gamma correction

Shashank Sharma shashank.sharma at intel.com
Wed Sep 16 10:37:12 PDT 2015


From: Kausal Malladi <kausalmalladi at gmail.com>

CHV/BSW platform supports two different pipe level gamma
correction modes, which are:
1. Legacy 8-bit mode
2. 10-bit CGM (Color Gamut Mapping) mode

This patch does the following:
1. Attaches Gamma property to CRTC
3. Adds the core Gamma correction function for CHV/BSW
4. Adds Gamma correction macros

Signed-off-by: Shashank Sharma <shashank.sharma at intel.com>
Signed-off-by: Kausal Malladi <kausalmalladi at gmail.com>
---
 drivers/gpu/drm/i915/i915_reg.h            |  12 +++
 drivers/gpu/drm/i915/intel_color_manager.c | 127 +++++++++++++++++++++++++++++
 drivers/gpu/drm/i915/intel_color_manager.h |  21 +++++
 3 files changed, 160 insertions(+)

diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h
index 67bf205..93aa1f9 100644
--- a/drivers/gpu/drm/i915/i915_reg.h
+++ b/drivers/gpu/drm/i915/i915_reg.h
@@ -7977,4 +7977,16 @@ enum skl_disp_power_wells {
 #define GEN9_VEBOX_MOCS_0	0xcb00	/* Video MOCS base register*/
 #define GEN9_BLT_MOCS_0		0xcc00	/* Blitter MOCS base register*/
 
+/* 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 2ba3fd7..222924d 100644
--- a/drivers/gpu/drm/i915/intel_color_manager.c
+++ b/drivers/gpu/drm/i915/intel_color_manager.c
@@ -66,6 +66,127 @@ int intel_color_manager_set_pipe_degamma(struct drm_device *dev,
 	return 0;
 }
 
+static int chv_set_gamma(struct drm_device *dev, struct drm_property_blob *blob,
+		  struct drm_crtc *crtc)
+{
+	bool flag = false;
+	enum pipe pipe;
+	u8 red_int, blue_int, green_int;
+	u16 red_fract, green_fract, blue_fract;
+	u32 red, green, blue;
+	u32 cgm_control_reg = 0;
+	u32 cgm_gamma_reg = 0;
+	u32 count = 0, num_samples, word;
+	int ret = 0, length;
+	struct drm_r32g32b32 *correction_values = NULL;
+	struct drm_palette *gamma_data;
+	struct drm_i915_private *dev_priv = dev->dev_private;
+
+	if (WARN_ON(!blob))
+		return -EINVAL;
+
+	gamma_data = (struct drm_palette *)blob->data;
+
+	if (gamma_data->version != GAMMA_DATA_STRUCT_VERSION) {
+		DRM_DEBUG_KMS("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);
+
+	switch (num_samples) {
+	case 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;
+		break;
+
+	case CHV_8BIT_GAMMA_MAX_VALS:
+	case CHV_10BIT_GAMMA_MAX_VALS:
+
+		count = 0;
+		cgm_gamma_reg = _PIPE_GAMMA_BASE(pipe);
+		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 |= 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 = true;
+			}
+		}
+
+		/* 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;
+		break;
+
+	default:
+		DRM_ERROR("Invalid number of samples for Gamma LUT\n");
+		ret = -EINVAL;
+	}
+
+	return ret;
+}
+
 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)
@@ -134,5 +255,11 @@ void intel_attach_color_properties_to_crtc(struct drm_device *dev,
 		DRM_DEBUG_DRIVER("Capabilities attached to CRTC\n");
 	}
 
+	if (config->cm_palette_after_ctm_property) {
+		drm_object_attach_property(mode_obj,
+			config->cm_palette_after_ctm_property, 0);
+		DRM_DEBUG_DRIVER("palette after CTM attached to CRTC\n");
+	}
+
 	kfree(palette_caps);
 }
diff --git a/drivers/gpu/drm/i915/intel_color_manager.h b/drivers/gpu/drm/i915/intel_color_manager.h
index 402b825..5f800c9 100644
--- a/drivers/gpu/drm/i915/intel_color_manager.h
+++ b/drivers/gpu/drm/i915/intel_color_manager.h
@@ -28,6 +28,27 @@
 #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 COLOR_STRUCT_VERSION			1
 #define CHV_10BIT_GAMMA_MAX_VALS		257
 #define CHV_DEGAMMA_MAX_VALS			65
+
+/* Gamma correction */
+#define 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)
-- 
1.9.1



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