drm/i915/color: Extract icl_read_luts()

For icl+, have hw read out to create hw blob of gamma
lut values. icl+ platforms supports multi segmented gamma
mode by default, add hw lut creation for this mode.

This will be used to validate gamma programming using dsb
(display state buffer) which is a tgl specific feature.

Major change done-removal of readouts of coarse and fine segments
because PAL_PREC_DATA register isn't giving propoer values.
State checker limited only to "fine segment"

v2: -readout code for multisegmented gamma has to come
     up with some intermediate entries that aren't preserved
     in hardware (Jani N)
    -linear interpolation (Ville)
    -moved common code to check gamma_enable to specific funcs,
     since icl doesn't support that
v3: -use u16 instead of __u16 [Jani N]
    -used single lut [Jani N]
    -improved and more readable for loops [Jani N]
    -read values directly to actual locations and then fill gaps [Jani N]
    -moved cleaning to patch 1 [Jani N]
    -renamed icl_read_lut_multi_seg() to icl_read_lut_multi_segment to
     make it similar to icl_load_luts()
    -renamed icl_compute_interpolated_gamma_blob() to
     icl_compute_interpolated_gamma_lut_values() more sensible, I guess
v4: -removed interpolated func for creating gamma lut values
    -removed readouts of fine and coarse segments, failure to read PAL_PREC_DATA
     correctly
Signed-off-by: Swati Sharma <swati2.sharma@intel.com>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/1569096654-24433-3-git-send-email-swati2.sharma@intel.com

drivers/gpu/drm/i915/display/intel_color.c

@@ -1402,6 +1402,9 @@ static int icl_color_check(struct intel_crtc_state *crtc_state)
 
 static int i9xx_gamma_precision(const struct intel_crtc_state *crtc_state)
 {
+	if (!crtc_state->gamma_enable)
+		return 0;
+
 	switch (crtc_state->gamma_mode) {
 	case GAMMA_MODE_MODE_8BIT:
 		return 8;
@@ -1415,6 +1418,9 @@ static int i9xx_gamma_precision(const struct intel_crtc_state *crtc_state)
 
 static int ilk_gamma_precision(const struct intel_crtc_state *crtc_state)
 {
+	if (!crtc_state->gamma_enable)
+		return 0;
+
 	if ((crtc_state->csc_mode & CSC_POSITION_BEFORE_GAMMA) == 0)
 		return 0;
 
@@ -1431,6 +1437,9 @@ static int ilk_gamma_precision(const struct intel_crtc_state *crtc_state)
 
 static int chv_gamma_precision(const struct intel_crtc_state *crtc_state)
 {
+	if (!crtc_state->gamma_enable)
+		return 0;
+
 	if (crtc_state->cgm_mode & CGM_PIPE_MODE_GAMMA)
 		return 10;
 	else
@@ -1439,6 +1448,9 @@ static int chv_gamma_precision(const struct intel_crtc_state *crtc_state)
 
 static int glk_gamma_precision(const struct intel_crtc_state *crtc_state)
 {
+	if (!crtc_state->gamma_enable)
+		return 0;
+
 	switch (crtc_state->gamma_mode) {
 	case GAMMA_MODE_MODE_8BIT:
 		return 8;
@@ -1450,21 +1462,39 @@ static int glk_gamma_precision(const struct intel_crtc_state *crtc_state)
 	}
 }
 
+static int icl_gamma_precision(const struct intel_crtc_state *crtc_state)
+{
+	if ((crtc_state->gamma_mode & POST_CSC_GAMMA_ENABLE) == 0)
+		return 0;
+
+	switch (crtc_state->gamma_mode & GAMMA_MODE_MODE_MASK) {
+	case GAMMA_MODE_MODE_8BIT:
+		return 8;
+	case GAMMA_MODE_MODE_10BIT:
+		return 10;
+	case GAMMA_MODE_MODE_12BIT_MULTI_SEGMENTED:
+		return 16;
+	default:
+		MISSING_CASE(crtc_state->gamma_mode);
+		return 0;
+	}
+
+}
+
 int intel_color_get_gamma_bit_precision(const struct intel_crtc_state *crtc_state)
 {
 	struct intel_crtc *crtc = to_intel_crtc(crtc_state->base.crtc);
 	struct drm_i915_private *dev_priv = to_i915(crtc->base.dev);
 
-	if (!crtc_state->gamma_enable)
-		return 0;
-
 	if (HAS_GMCH(dev_priv)) {
 		if (IS_CHERRYVIEW(dev_priv))
 			return chv_gamma_precision(crtc_state);
 		else
 			return i9xx_gamma_precision(crtc_state);
 	} else {
-		if (IS_CANNONLAKE(dev_priv) || IS_GEMINILAKE(dev_priv))
+		if (INTEL_GEN(dev_priv) >= 11)
+			return icl_gamma_precision(crtc_state);
+		else if (IS_CANNONLAKE(dev_priv) || IS_GEMINILAKE(dev_priv))
 			return glk_gamma_precision(crtc_state);
 		else if (IS_IRONLAKE(dev_priv))
 			return ilk_gamma_precision(crtc_state);
@@ -1495,6 +1525,20 @@ static bool intel_color_lut_entry_equal(struct drm_color_lut *lut1,
 	return true;
 }
 
+static bool intel_color_lut_entry_multi_equal(struct drm_color_lut *lut1,
+					      struct drm_color_lut *lut2,
+					      int lut_size, u32 err)
+{
+	int i;
+
+	for (i = 0; i < 9; i++) {
+		if (!err_check(&lut1[i], &lut2[i], err))
+			return false;
+	}
+
+	return true;
+}
+
 bool intel_color_lut_equal(struct drm_property_blob *blob1,
 			   struct drm_property_blob *blob2,
 			   u32 gamma_mode, u32 bit_precision)
@@ -1513,16 +1557,8 @@ bool intel_color_lut_equal(struct drm_property_blob *blob1,
 	lut_size2 = drm_color_lut_size(blob2);
 
 	/* check sw and hw lut size */
-	switch (gamma_mode) {
-	case GAMMA_MODE_MODE_8BIT:
-	case GAMMA_MODE_MODE_10BIT:
 	if (lut_size1 != lut_size2)
 		return false;
-		break;
-	default:
-		MISSING_CASE(gamma_mode);
-			return false;
-	}
 
 	lut1 = blob1->data;
 	lut2 = blob2->data;
@@ -1530,13 +1566,18 @@ bool intel_color_lut_equal(struct drm_property_blob *blob1,
 	err = 0xffff >> bit_precision;
 
 	/* check sw and hw lut entry to be equal */
-	switch (gamma_mode) {
+	switch (gamma_mode & GAMMA_MODE_MODE_MASK) {
 	case GAMMA_MODE_MODE_8BIT:
 	case GAMMA_MODE_MODE_10BIT:
 		if (!intel_color_lut_entry_equal(lut1, lut2,
 						 lut_size2, err))
 			return false;
 		break;
+	case GAMMA_MODE_MODE_12BIT_MULTI_SEGMENTED:
+		if (!intel_color_lut_entry_multi_equal(lut1, lut2,
+						       lut_size2, err))
+			return false;
+		break;
 	default:
 		MISSING_CASE(gamma_mode);
 			return false;
@@ -1776,6 +1817,60 @@ static void glk_read_luts(struct intel_crtc_state *crtc_state)
 		crtc_state->base.gamma_lut = glk_read_lut_10(crtc_state, PAL_PREC_INDEX_VALUE(0));
 }
 
+static struct drm_property_blob *
+icl_read_lut_multi_segment(const struct intel_crtc_state *crtc_state)
+{
+	struct intel_crtc *crtc = to_intel_crtc(crtc_state->base.crtc);
+	struct drm_i915_private *dev_priv = to_i915(crtc->base.dev);
+	int lut_size = INTEL_INFO(dev_priv)->color.gamma_lut_size;
+	enum pipe pipe = crtc->pipe;
+	struct drm_property_blob *blob;
+	struct drm_color_lut *blob_data;
+	u32 i, val1, val2;
+
+	blob = drm_property_create_blob(&dev_priv->drm,
+					sizeof(struct drm_color_lut) * lut_size,
+					NULL);
+	if (IS_ERR(blob))
+		return NULL;
+
+	blob_data = blob->data;
+
+	I915_WRITE(PREC_PAL_MULTI_SEG_INDEX(pipe), PAL_PREC_AUTO_INCREMENT);
+
+	for (i = 0; i < 9; i++) {
+		val1 = I915_READ(PREC_PAL_MULTI_SEG_DATA(pipe));
+		val2 = I915_READ(PREC_PAL_MULTI_SEG_DATA(pipe));
+
+		blob_data[i].red = REG_FIELD_GET(PAL_PREC_MULTI_SEG_RED_UDW_MASK, val2) << 6 |
+				   REG_FIELD_GET(PAL_PREC_MULTI_SEG_RED_LDW_MASK, val1);
+		blob_data[i].green = REG_FIELD_GET(PAL_PREC_MULTI_SEG_GREEN_UDW_MASK, val2) << 6 |
+				     REG_FIELD_GET(PAL_PREC_MULTI_SEG_GREEN_LDW_MASK, val1);
+		blob_data[i].blue = REG_FIELD_GET(PAL_PREC_MULTI_SEG_BLUE_UDW_MASK, val2) << 6 |
+				    REG_FIELD_GET(PAL_PREC_MULTI_SEG_BLUE_LDW_MASK, val1);
+	}
+
+	/*
+	 * FIXME readouts from PAL_PREC_DATA register aren't giving correct values
+	 * in the case of fine and coarse segments. Restricting readouts only for
+	 * super fine segment as of now.
+	 */
+
+	return blob;
+}
+
+static void icl_read_luts(struct intel_crtc_state *crtc_state)
+{
+	if ((crtc_state->gamma_mode & GAMMA_MODE_MODE_MASK) ==
+	    GAMMA_MODE_MODE_8BIT)
+		crtc_state->base.gamma_lut = i9xx_read_lut_8(crtc_state);
+	else if ((crtc_state->gamma_mode & GAMMA_MODE_MODE_MASK) ==
+		 GAMMA_MODE_MODE_12BIT_MULTI_SEGMENTED)
+		crtc_state->base.gamma_lut = icl_read_lut_multi_segment(crtc_state);
+	else
+		crtc_state->base.gamma_lut = glk_read_lut_10(crtc_state, PAL_PREC_INDEX_VALUE(0));
+}
+
 void intel_color_init(struct intel_crtc *crtc)
 {
 	struct drm_i915_private *dev_priv = to_i915(crtc->base.dev);
@@ -1819,6 +1914,7 @@ void intel_color_init(struct intel_crtc *crtc)
 
 		if (INTEL_GEN(dev_priv) >= 11) {
 			dev_priv->display.load_luts = icl_load_luts;
+			dev_priv->display.read_luts = icl_read_luts;
 		} else if (IS_CANNONLAKE(dev_priv) || IS_GEMINILAKE(dev_priv)) {
 			dev_priv->display.load_luts = glk_load_luts;
 			dev_priv->display.read_luts = glk_read_luts;

drivers/gpu/drm/i915/i915_reg.h

@@ -10410,6 +10410,12 @@ enum skl_power_gate {
 
 #define _PAL_PREC_MULTI_SEG_DATA_A	0x4A40C
 #define _PAL_PREC_MULTI_SEG_DATA_B	0x4AC0C
+#define  PAL_PREC_MULTI_SEG_RED_LDW_MASK   REG_GENMASK(29, 24)
+#define  PAL_PREC_MULTI_SEG_RED_UDW_MASK   REG_GENMASK(29, 20)
+#define  PAL_PREC_MULTI_SEG_GREEN_LDW_MASK REG_GENMASK(19, 14)
+#define  PAL_PREC_MULTI_SEG_GREEN_UDW_MASK REG_GENMASK(19, 10)
+#define  PAL_PREC_MULTI_SEG_BLUE_LDW_MASK  REG_GENMASK(9, 4)
+#define  PAL_PREC_MULTI_SEG_BLUE_UDW_MASK  REG_GENMASK(9, 0)
 
 #define PREC_PAL_MULTI_SEG_INDEX(pipe)	_MMIO_PIPE(pipe, \
 					_PAL_PREC_MULTI_SEG_INDEX_A, \