[Intel-gfx] [PATCH 2/2] drm/i915/glk: Program pre_csc_gamma with unity gamma

[Dhanya Pillai]

From: Dhanya <dhanya.p.r at intel.com>

For GLK, Pre-CSC Gamma correction get enabled/disabled based
on "Pipe CSC Enable" bit in the PLANE_COLOR_CTL.
This patch programs Unity Gamma in these registers.

Signed-off-by: Dhanya <dhanya.p.r at intel.com>
---
 drivers/gpu/drm/i915/i915_reg.h    | 13 +++++++++++++
 drivers/gpu/drm/i915/intel_color.c | 35 +++++++++++++++++++++++++++++++++++
 2 files changed, 48 insertions(+)

diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h
index be756bd..ab6684d 100644
--- a/drivers/gpu/drm/i915/i915_reg.h
+++ b/drivers/gpu/drm/i915/i915_reg.h
@@ -8512,6 +8512,19 @@ enum {
 #define PREC_PAL_GC_MAX(pipe, i)	_MMIO(_PIPE(pipe, _PAL_PREC_GC_MAX_A, _PAL_PREC_GC_MAX_B) + (i) * 4)
 #define PREC_PAL_EXT_GC_MAX(pipe, i)	_MMIO(_PIPE(pipe, _PAL_PREC_EXT_GC_MAX_A, _PAL_PREC_EXT_GC_MAX_B) + (i) * 4)
 
+/*pipe pre-csc gamma LUTS on GEN10+*/
+#define PRE_CSC_GAMMA_AUTO_INCREMENT (1 << 10)
+#define PRE_CSC_GAMMA_LUT_SIZE 35
+#define _PRE_CSC_GAMMA_INDEX_A  0x4A484
+#define _PRE_CSC_GAMMA_INDEX_B  0x4AC84
+#define _PRE_CSC_GAMMA_INDEX_C  0x4B484
+#define _PRE_CSC_GAMMA_DATA_A  0x4A488
+#define _PRE_CSC_GAMMA_DATA_B  0x4AC88
+#define _PRE_CSC_GAMMA_DATA_C  0x4B488
+
+#define PRE_CSC_GAMMA_INDEX(pipe)   _MMIO_PIPE(pipe, _PRE_CSC_GAMMA_INDEX_A, _PRE_CSC_GAMMA_INDEX_B)
+#define PRE_CSC_GAMMA_DATA(pipe)    _MMIO_PIPE(pipe, _PRE_CSC_GAMMA_DATA_A, _PRE_CSC_GAMMA_DATA_B)
+
 /* pipe CSC & degamma/gamma LUTs on CHV */
 #define _CGM_PIPE_A_CSC_COEFF01	(VLV_DISPLAY_BASE + 0x67900)
 #define _CGM_PIPE_A_CSC_COEFF23	(VLV_DISPLAY_BASE + 0x67904)
diff --git a/drivers/gpu/drm/i915/intel_color.c b/drivers/gpu/drm/i915/intel_color.c
index 8bfcdcd..05dcaa6 100644
--- a/drivers/gpu/drm/i915/intel_color.c
+++ b/drivers/gpu/drm/i915/intel_color.c
@@ -91,6 +91,32 @@ static void ctm_mult_by_limited(uint64_t *result, int64_t *input)
 	}
 }
 
+/*Set up the Pre-CSC Gamma correction for Gen9+*/
+static void i9xx_load_pre_csc_gamma_lut(struct drm_crtc_state *crtc_state)
+{
+	struct drm_crtc *crtc = crtc_state->crtc;
+	struct drm_device *dev = crtc->dev;
+	struct drm_i915_private *dev_priv = to_i915(dev);
+	struct intel_crtc *intel_crtc = to_intel_crtc(crtc);
+	int i, pipe = intel_crtc->pipe;
+
+	I915_WRITE(PRE_CSC_GAMMA_INDEX(pipe),
+			PRE_CSC_GAMMA_AUTO_INCREMENT);
+
+	for (i = 0; i < PRE_CSC_GAMMA_LUT_SIZE; i++) {
+		uint32_t v = (i * ((1 << 16) - 1));
+
+		I915_WRITE(PRE_CSC_GAMMA_DATA(pipe), v);
+	}
+	/*
+	 * Reset the index, otherwise it prevents the legacy palette to be
+	 * written properly.
+	 */
+	I915_WRITE(PRE_CSC_GAMMA_INDEX(pipe), 0);
+
+}
+
+
 /* Set up the pipe CSC unit. */
 static void i9xx_load_csc_matrix(struct drm_crtc_state *crtc_state)
 {
@@ -101,6 +127,15 @@ static void i9xx_load_csc_matrix(struct drm_crtc_state *crtc_state)
 	uint16_t coeffs[9] = { 0, };
 	struct intel_crtc_state *intel_crtc_state = to_intel_crtc_state(crtc_state);
 
+	/*
+	 *For Gen9_LP+ Pre-CSC Gamma correction get enabled/disabled based on
+	 *"Pipe CSC Enable" bit in the PLANE_COLOR_CTL. We need to program 1:1
+	 * gamma value in these.
+	 */
+
+	if (IS_GEN9_LP(dev_priv) && !IS_BROXTON(dev_priv))
+		i9xx_load_pre_csc_gamma_lut(crtc_state);
+
 	if (crtc_state->ctm) {
 		struct drm_color_ctm *ctm =
 			(struct drm_color_ctm *)crtc_state->ctm->data;
-- 
1.9.1