[PATCH v7 20/25] drm/i915: BDW: Pipe level Gamma correction

Shashank Sharma
2015-10-20T12:34:47Z

BDW/SKL/BXT platforms support various Gamma correction modes
which are:
1. Legacy 8-bit mode
2. 10-bit mode
3. Split mode
4. 12-bit mode

This patch does the following:
1. Adds the core function to program Gamma correction values
for BDW/SKL/BXT platforms
2. Adds Gamma correction macros/defines

Signed-off-by: Shashank Sharma <shashank.sharma@intel.com>
Signed-off-by: Kausal Malladi <kausalmalladi@gmail.com>
---
drivers/gpu/drm/i915/i915_reg.h | 25 ++-
drivers/gpu/drm/i915/intel_color_manager.c | 281 +++++++++++++++++++++++++++++
drivers/gpu/drm/i915/intel_color_manager.h | 6 +
3 files changed, 310 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h
index 3db42f4..39fbafc 100644
--- a/drivers/gpu/drm/i915/i915_reg.h
+++ b/drivers/gpu/drm/i915/i915_reg.h
@@ -5685,11 +5685,15 @@ enum skl_disp_power_wells {
/* legacy palette */
#define _LGC_PALETTE_A 0x4a000
#define _LGC_PALETTE_B 0x4a800
-#define LGC_PALETTE(pipe, i) (_PIPE(pipe, _LGC_PALETTE_A, _LGC_PALETTE_B) + (i) * 4)
+#define _LGC_PALETTE_C 0x4b000
+#define LGC_PALETTE(pipe, i) (_PIPE3(pipe, _LGC_PALETTE_A, _LGC_PALETTE_B, \
+ _LGC_PALETTE_C) + (i) * 4)

#define _GAMMA_MODE_A 0x4a480
#define _GAMMA_MODE_B 0x4ac80
-#define GAMMA_MODE(pipe) _PIPE(pipe, _GAMMA_MODE_A, _GAMMA_MODE_B)
+#define _GAMMA_MODE_C 0x4b480
+#define GAMMA_MODE(pipe) \
+ _PIPE3(pipe, _GAMMA_MODE_A, _GAMMA_MODE_B, _GAMMA_MODE_C)
#define GAMMA_MODE_MODE_MASK (3 << 0)
#define GAMMA_MODE_MODE_8BIT (0 << 0)
#define GAMMA_MODE_MODE_10BIT (1 << 0)
@@ -8172,6 +8176,23 @@ enum skl_disp_power_wells {
#define _PIPE_CSC_BASE(pipe) \
(_PIPE3(pipe, PIPEA_CGM_CSC, PIPEB_CGM_CSC, PIPEC_CGM_CSC))

+/* BDW gamma correction */
+#define PAL_PREC_INDEX_A 0x4A400
+#define PAL_PREC_INDEX_B 0x4AC00
+#define PAL_PREC_INDEX_C 0x4B400
+#define PAL_PREC_DATA_A 0x4A404
+#define PAL_PREC_DATA_B 0x4AC04
+#define PAL_PREC_DATA_C 0x4B404
+#define PAL_PREC_GCMAX_A 0x4A410
+#define PAL_PREC_GCMAX_B 0x4AC10
+#define PAL_PREC_GCMAX_C 0x4B410
+
+#define _PREC_PAL_INDEX(pipe) \
+ (_PIPE3(pipe, PAL_PREC_INDEX_A, PAL_PREC_INDEX_B, PAL_PREC_INDEX_C))
+#define _PREC_PAL_DATA(pipe) \
+ (_PIPE3(pipe, PAL_PREC_DATA_A, PAL_PREC_DATA_B, PAL_PREC_DATA_C))
+#define _PREC_PAL_GCMAX(pipe) \
+ (_PIPE3(pipe, PAL_PREC_GCMAX_A, PAL_PREC_GCMAX_B, PAL_PREC_GCMAX_C))

#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 ac4074a..fbb5d03 100644
--- a/drivers/gpu/drm/i915/intel_color_manager.c
+++ b/drivers/gpu/drm/i915/intel_color_manager.c
@@ -27,6 +27,285 @@

#include "intel_color_manager.h"

+static void bdw_write_8bit_gamma_legacy(struct drm_device *dev,
+ struct drm_r32g32b32 *correction_values, u32 palette)
+{
+ u16 blue_fract, green_fract, red_fract;
+ u32 blue, green, red;
+ u32 count = 0;
+ u32 word = 0;
+ struct drm_i915_private *dev_priv = dev->dev_private;
+
+ while (count < BDW_8BIT_GAMMA_MAX_VALS) {
+ blue = correction_values[count].b32;
+ green = correction_values[count].g32;
+ red = correction_values[count].r32;
+
+ /*
+ * Maximum possible gamma correction value supported
+ * for BDW is 0xFFFFFFFF, so clamp the values accordingly
+ */
+ if (blue >= BDW_MAX_GAMMA)
+ blue = BDW_MAX_GAMMA;
+ if (green >= BDW_MAX_GAMMA)
+ green = BDW_MAX_GAMMA;
+ if (red >= BDW_MAX_GAMMA)
+ red = BDW_MAX_GAMMA;
+
+ blue_fract = GET_BITS(blue, 16, 8);
+ green_fract = GET_BITS(green, 16, 8);
+ red_fract = GET_BITS(red, 16, 8);
+
+ /* Blue (7:0) Green (15:8) and Red (23:16) */
+ SET_BITS(word, blue_fract, 0, 8);
+ SET_BITS(word, green_fract, 8, 8);
+ SET_BITS(word, red_fract, 16, 8);
+ I915_WRITE(palette, word);
+ palette += 4;
+ count++;
+ }
+}
+
+static void bdw_write_10bit_gamma_precision(struct drm_device *dev,
+ struct drm_r32g32b32 *correction_values, u32 pal_prec_data,
+ u32 no_of_coeff)
+{
+ u16 blue_fract, green_fract, red_fract;
+ u32 word = 0;
+ u32 count = 0;
+ u32 blue, green, red;
+ struct drm_i915_private *dev_priv = dev->dev_private;
+
+ while (count < no_of_coeff) {
+
+ blue = correction_values[count].b32;
+ green = correction_values[count].g32;
+ red = correction_values[count].r32;
+
+ /*
+ * Maximum possible gamma correction value supported
+ * for BDW is 0xFFFFFFFF, so clamp the values accordingly
+ */
+ if (blue >= BDW_MAX_GAMMA)
+ blue = BDW_MAX_GAMMA;
+ if (green >= BDW_MAX_GAMMA)
+ green = BDW_MAX_GAMMA;
+ if (red >= BDW_MAX_GAMMA)
+ red = BDW_MAX_GAMMA;
+
+ /*
+ * Gamma correction values are sent in 8.24 format
+ * with 8 int and 24 fraction bits. BDW 10 bit gamma
+ * unit expects correction registers to be programmed in
+ * 0.10 format, with 0 int and 16 fraction bits. So take
+ * MSB 10 bit values(bits 23-14) from the fraction part and
+ * prepare the correction registers.
+ */
+ blue_fract = GET_BITS(blue, 14, 10);
+ green_fract = GET_BITS(green, 14, 10);
+ red_fract = GET_BITS(red, 14, 10);
+
+ /* Arrange: Red (29:20) Green (19:10) and Blue (9:0) */
+ SET_BITS(word, red_fract, 20, 10);
+ SET_BITS(word, green_fract, 10, 10);
+ SET_BITS(word, blue_fract, 0, 10);
+ I915_WRITE(pal_prec_data, word);
+ count++;
+ }
+ DRM_DEBUG_DRIVER("Gamma correction programmed\n");
+}
+
+static void bdw_write_12bit_gamma_precision(struct drm_device *dev,
+ struct drm_r32g32b32 *correction_values, u32 pal_prec_data,
+ enum pipe pipe)
+{
+ uint16_t blue_fract, green_fract, red_fract;
+ uint32_t gcmax;
+ uint32_t word = 0;
+ uint32_t count = 0;
+ uint32_t gcmax_reg;
+ u32 blue, green, red;
+ struct drm_i915_private *dev_priv = dev->dev_private;
+
+ /* Program first 512 values in precision palette */
+ while (count < BDW_12BIT_GAMMA_MAX_VALS - 1) {
+
+ blue = correction_values[count].b32;
+ green = correction_values[count].g32;
+ red = correction_values[count].r32;
+
+ /*
+ * Maximum possible gamma correction value supported
+ * for BDW is 0xFFFFFFFF, so clamp the values accordingly
+ */
+ if (blue >= BDW_MAX_GAMMA)
+ blue = BDW_MAX_GAMMA;
+ if (green >= BDW_MAX_GAMMA)
+ green = BDW_MAX_GAMMA;
+ if (red >= BDW_MAX_GAMMA)
+ red = BDW_MAX_GAMMA;
+
+ /*
+ * Framework's general gamma format is 8.24 (8 int 16 fraction)
+ * BDW Platform's supported gamma format is 16 bit correction
+ * values in 0.16 format. So extract higher 16 fraction bits
+ * from 8.24 gamma correction values.
+ */
+ red_fract = GET_BITS(red, 8, 16);
+ green_fract = GET_BITS(green, 8, 16);
+ blue_fract = GET_BITS(blue, 8, 16);
+
+ /*
+ * From the bspec:
+ * For 12 bit gamma correction, program precision palette
+ * with 16 bits per color in a 0.16 format with 0 integer and
+ * 16 fractional bits (upper 10 bits in odd indexes, lower 6
+ * bits in even indexes)
+ */
+
+ /* Even index: Lower 6 bits from correction should go as MSB */
+ SET_BITS(word, GET_BITS(red_fract, 0, 6), 24, 6);
+ SET_BITS(word, GET_BITS(green_fract, 0, 6), 14, 6);
+ SET_BITS(word, GET_BITS(blue_fract, 0, 6), 4, 6);
+ I915_WRITE(pal_prec_data, word);
+
+ word = 0x0;
+ /* Odd index: Upper 10 bits of correction should go as MSB */
+ SET_BITS(word, GET_BITS(red_fract, 6, 10), 20, 10);
+ SET_BITS(word, GET_BITS(green_fract, 6, 10), 10, 10);
+ SET_BITS(word, GET_BITS(blue_fract, 6, 10), 0, 10);
+
+ I915_WRITE(pal_prec_data, word);
+ count++;
+ }
+
+ /* Now program the 513th value in GCMAX regs */
+ word = 0;
+ gcmax_reg = _PREC_PAL_GCMAX(pipe);
+ gcmax = min_t(u32, GET_BITS(correction_values[count].r32, 8, 17),
+ BDW_MAX_GAMMA);
+ SET_BITS(word, gcmax, 0, 17);
+ I915_WRITE(gcmax_reg, word);
+ gcmax_reg += 4;
+
+ word = 0;
+ gcmax = min_t(u32, GET_BITS(correction_values[count].g32, 8, 17),
+ BDW_MAX_GAMMA);
+ SET_BITS(word, gcmax, 0, 17);
+ I915_WRITE(gcmax_reg, word);
+ gcmax_reg += 4;
+
+ word = 0;
+ gcmax = min_t(u32, GET_BITS(correction_values[count].b32, 8, 17),
+ BDW_MAX_GAMMA);
+ SET_BITS(word, gcmax, 0, 17);
+ I915_WRITE(gcmax_reg, word);
+}
+
+/* Apply unity gamma for gamma reset */
+static void bdw_reset_gamma(struct drm_i915_private *dev_priv,
+ enum pipe pipe)
+{
+ u16 count = 0;
+ u32 val;
+ u32 pal_prec_data = LGC_PALETTE(pipe, 0);
+
+ DRM_DEBUG_DRIVER("\n");
+
+ /* Reset the palette for unit gamma */
+ while (count < BDW_8BIT_GAMMA_MAX_VALS) {
+ /* Red (23:16) Green (15:8) and Blue (7:0) */
+ val = (count << 16) | (count << 8) | count;
+ I915_WRITE(pal_prec_data, val);
+ pal_prec_data += 4;
+ count++;
+ }
+}
+
+static int bdw_set_gamma(struct drm_device *dev, struct drm_property_blob *blob,
+ struct drm_crtc *crtc)
+{
+ enum pipe pipe;
+ int num_samples;
+ u32 mode, pal_prec_index, pal_prec_data, index;
+ u32 word = 0;
+ struct drm_palette *gamma_data;
+ struct drm_crtc_state *state = crtc->state;
+ struct drm_i915_private *dev_priv = dev->dev_private;
+ struct drm_r32g32b32 *correction_values = NULL;
+
+ if (WARN_ON(!blob))
+ return -EINVAL;
+
+ gamma_data = (struct drm_palette *)blob->data;
+ pipe = to_intel_crtc(crtc)->pipe;
+ num_samples = blob->length / sizeof(struct drm_r32g32b32);
+
+ pal_prec_index = _PREC_PAL_INDEX(pipe);
+ pal_prec_data = _PREC_PAL_DATA(pipe);
+
+ correction_values = (struct drm_r32g32b32 *)&gamma_data->lut;
+ index = I915_READ(pal_prec_index);
+
+ switch (num_samples) {
+ case GAMMA_DISABLE_VALS:
+ /* Disable Gamma functionality on Pipe */
+ DRM_DEBUG_DRIVER("Disabling gamma on Pipe %c\n",
+ pipe_name(pipe));
+ mode = I915_READ(GAMMA_MODE(pipe));
+ if ((mode & GAMMA_MODE_MODE_MASK) == GAMMA_MODE_MODE_12BIT)
+ bdw_reset_gamma(dev_priv, pipe);
+ state->palette_after_ctm_blob = NULL;
+ word = GAMMA_MODE_MODE_8BIT;
+ break;
+
+ case BDW_8BIT_GAMMA_MAX_VALS:
+ /* Legacy palette */
+ bdw_write_8bit_gamma_legacy(dev, correction_values,
+ LGC_PALETTE(pipe, 0));
+ word = GAMMA_MODE_MODE_8BIT;
+ break;
+
+ case BDW_SPLITGAMMA_MAX_VALS:
+ index |= BDW_INDEX_AUTO_INCREMENT | BDW_INDEX_SPLIT_MODE;
+ I915_WRITE(pal_prec_index, index);
+ bdw_write_10bit_gamma_precision(dev, correction_values,
+ pal_prec_data, BDW_SPLITGAMMA_MAX_VALS);
+ word = GAMMA_MODE_MODE_SPLIT;
+ break;
+
+ case BDW_12BIT_GAMMA_MAX_VALS:
+ index |= BDW_INDEX_AUTO_INCREMENT;
+ index &= ~BDW_INDEX_SPLIT_MODE;
+ I915_WRITE(pal_prec_index, index);
+ bdw_write_12bit_gamma_precision(dev, correction_values,
+ pal_prec_data, pipe);
+ word = GAMMA_MODE_MODE_12BIT;
+ break;
+
+ case BDW_10BIT_GAMMA_MAX_VALS:
+ index |= BDW_INDEX_AUTO_INCREMENT;
+ index &= ~BDW_INDEX_SPLIT_MODE;
+ I915_WRITE(pal_prec_index, index);
+ bdw_write_10bit_gamma_precision(dev, correction_values,
+ pal_prec_data, BDW_10BIT_GAMMA_MAX_VALS);
+ word = GAMMA_MODE_MODE_10BIT;
+ break;
+
+ default:
+ DRM_ERROR("Invalid number of samples\n");
+ return -EINVAL;
+ }
+
+ /* Set gamma mode on pipe control reg */
+ mode = I915_READ(GAMMA_MODE(pipe));
+ mode &= ~GAMMA_MODE_MODE_MASK;
+ I915_WRITE(GAMMA_MODE(pipe), mode | word);
+ DRM_DEBUG_DRIVER("Gamma applied on pipe %c\n",
+ pipe_name(pipe));
+ return 0;
+}
+
static s32 chv_prepare_csc_coeff(s64 csc_value)
{
s32 csc_int_value;
@@ -303,6 +582,8 @@ void intel_color_manager_crtc_commit(struct drm_device *dev,
/* Gamma correction is platform specific */
if (IS_CHERRYVIEW(dev))
ret = chv_set_gamma(dev, blob, crtc);
+ else if (IS_BROADWELL(dev) || IS_GEN9(dev))
+ ret = bdw_set_gamma(dev, blob, crtc);

if (ret)
DRM_ERROR("set Gamma correction failed\n");
diff --git a/drivers/gpu/drm/i915/intel_color_manager.h b/drivers/gpu/drm/i915/intel_color_manager.h
index 271246a..6c7cb08 100644
--- a/drivers/gpu/drm/i915/intel_color_manager.h
+++ b/drivers/gpu/drm/i915/intel_color_manager.h
@@ -92,3 +92,9 @@

/* Gamma on BDW */
#define BDW_SPLITGAMMA_MAX_VALS 512
+#define BDW_8BIT_GAMMA_MAX_VALS 256
+#define BDW_10BIT_GAMMA_MAX_VALS 1024
+#define BDW_12BIT_GAMMA_MAX_VALS 513
+#define BDW_MAX_GAMMA ((1 << 24) - 1)
+#define BDW_INDEX_AUTO_INCREMENT (1 << 15)
+#define BDW_INDEX_SPLIT_MODE (1 << 31)