[RFC PATCH 1/2] drm/msm/dpu: add dsc helper functions

[Kuogee Hsieh]

Add DSC helper functions based on DSC configuration profiles to produce
DSC related runtime parameters through both table look up and runtime
calculation to support DSC on DPU.

There are 6 different DSC configuration profiles are supported currently.
DSC configuration profiles are differiented by 5 keys, DSC version (V1.1),
chroma (444/422/420), colorspace (RGB/YUV), bpc(8/10),
bpp (6/7/7.5/8/9/10/12/15) and SCR (0/1).

Only DSC version V1.1 added and V1.2 will be added later.

Signed-off-by: Kuogee Hsieh <quic_khsieh@xxxxxxxxxxx>
---
 drivers/gpu/drm/msm/Makefile                   |   1 +
 drivers/gpu/drm/msm/disp/dpu1/dpu_dsc_helper.c | 209 +++++++++++++++++++++++++
 drivers/gpu/drm/msm/disp/dpu1/dpu_dsc_helper.h |  34 ++++
 3 files changed, 244 insertions(+)
 create mode 100644 drivers/gpu/drm/msm/disp/dpu1/dpu_dsc_helper.c
 create mode 100644 drivers/gpu/drm/msm/disp/dpu1/dpu_dsc_helper.h

diff --git a/drivers/gpu/drm/msm/Makefile b/drivers/gpu/drm/msm/Makefile
index 7274c412..28cf52b 100644
--- a/drivers/gpu/drm/msm/Makefile
+++ b/drivers/gpu/drm/msm/Makefile
@@ -65,6 +65,7 @@ msm-$(CONFIG_DRM_MSM_DPU) += \
 	disp/dpu1/dpu_hw_catalog.o \
 	disp/dpu1/dpu_hw_ctl.o \
 	disp/dpu1/dpu_hw_dsc.o \
+	disp/dpu1/dpu_dsc_helper.o \
 	disp/dpu1/dpu_hw_interrupts.o \
 	disp/dpu1/dpu_hw_intf.o \
 	disp/dpu1/dpu_hw_lm.o \
diff --git a/drivers/gpu/drm/msm/disp/dpu1/dpu_dsc_helper.c b/drivers/gpu/drm/msm/disp/dpu1/dpu_dsc_helper.c
new file mode 100644
index 00000000..88207e9
--- /dev/null
+++ b/drivers/gpu/drm/msm/disp/dpu1/dpu_dsc_helper.c
@@ -0,0 +1,209 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (c) 2023. Qualcomm Innovation Center, Inc. All rights reserved
+ */
+
+#include <drm/display/drm_dsc_helper.h>
+#include "msm_drv.h"
+#include "dpu_kms.h"
+#include "dpu_hw_dsc.h"
+#include "dpu_dsc_helper.h"
+
+
+#define DPU_DSC_PPS_SIZE       128
+
+enum dpu_dsc_ratio_type {
+	DSC_V11_8BPC_8BPP,
+	DSC_V11_10BPC_8BPP,
+	DSC_V11_10BPC_10BPP,
+	DSC_V11_SCR1_8BPC_8BPP,
+	DSC_V11_SCR1_10BPC_8BPP,
+	DSC_V11_SCR1_10BPC_10BPP,
+	DSC_RATIO_TYPE_MAX
+};
+
+
+static u16 dpu_dsc_rc_buf_thresh[DSC_NUM_BUF_RANGES - 1] = {
+		0x0e, 0x1c, 0x2a, 0x38, 0x46, 0x54,
+		0x62, 0x69, 0x70, 0x77, 0x79, 0x7b, 0x7d, 0x7e
+};
+
+/*
+ * Rate control - Min QP values for each ratio type in dpu_dsc_ratio_type
+ */
+static char dpu_dsc_rc_range_min_qp[DSC_RATIO_TYPE_MAX][DSC_NUM_BUF_RANGES] = {
+	/* DSC v1.1 */
+	{0, 0, 1, 1, 3, 3, 3, 3, 3, 3, 5, 5, 5, 7, 13},
+	{0, 4, 5, 5, 7, 7, 7, 7, 7, 7, 9, 9, 9, 11, 17},
+	{0, 4, 5, 6, 7, 7, 7, 7, 7, 7, 9, 9, 9, 11, 15},
+	/* DSC v1.1 SCR and DSC v1.2 RGB 444 */
+	{0, 0, 1, 1, 3, 3, 3, 3, 3, 3, 5, 5, 5, 9, 12},
+	{0, 4, 5, 5, 7, 7, 7, 7, 7, 7, 9, 9, 9, 13, 16},
+	{0, 4, 5, 6, 7, 7, 7, 7, 7, 7, 9, 9, 9, 11, 15},
+};
+
+/*
+ * Rate control - Max QP values for each ratio type in dpu_dsc_ratio_type
+ */
+static char dpu_dsc_rc_range_max_qp[DSC_RATIO_TYPE_MAX][DSC_NUM_BUF_RANGES] = {
+	/* DSC v1.1 */
+	{4, 4, 5, 6, 7, 7, 7, 8, 9, 10, 11, 12, 13, 13, 15},
+	{4, 8, 9, 10, 11, 11, 11, 12, 13, 14, 15, 16, 17, 17, 19},
+	{7, 8, 9, 10, 11, 11, 11, 12, 13, 13, 14, 14, 15, 15, 16},
+	/* DSC v1.1 SCR and DSC v1.2 RGB 444 */
+	{4, 4, 5, 6, 7, 7, 7, 8, 9, 10, 10, 11, 11, 12, 13},
+	{8, 8, 9, 10, 11, 11, 11, 12, 13, 14, 14, 15, 15, 16, 17},
+	{7, 8, 9, 10, 11, 11, 11, 12, 13, 13, 14, 14, 15, 15, 16},
+};
+
+/*
+ * Rate control - bpg offset values for each ratio type in dpu_dsc_ratio_type
+ */
+static char dpu_dsc_rc_range_bpg[DSC_RATIO_TYPE_MAX][DSC_NUM_BUF_RANGES] = {
+	/* DSC v1.1 */
+	{2, 0, 0, -2, -4, -6, -8, -8, -8, -10, -10, -12, -12, -12, -12},
+	{2, 0, 0, -2, -4, -6, -8, -8, -8, -10, -10, -12, -12, -12, -12},
+	{2, 0, 0, -2, -4, -6, -8, -8, -8, -10, -10, -10, -12, -12, -12},
+	/* DSC v1.1 SCR and DSC V1.2 RGB 444 */
+	{2, 0, 0, -2, -4, -6, -8, -8, -8, -10, -10, -12, -12, -12, -12},
+	{2, 0, 0, -2, -4, -6, -8, -8, -8, -10, -10, -12, -12, -12, -12},
+	{2, 0, 0, -2, -4, -6, -8, -8, -8, -10, -10, -10, -12, -12, -12},
+};
+
+static struct dpu_dsc_rc_init_params_lut {
+	u32 rc_quant_incr_limit0;
+	u32 rc_quant_incr_limit1;
+	u32 initial_fullness_offset;
+	u32 initial_xmit_delay;
+	u32 second_line_bpg_offset;
+	u32 second_line_offset_adj;
+	u32 flatness_min_qp;
+	u32 flatness_max_qp;
+}  dpu_dsc_rc_init_param_lut[] = {
+	/* DSC v1.1 */
+	{11, 11, 6144, 512, 0, 0, 3, 12}, /* DSC_V11_8BPC_8BPP */
+	{15, 15, 6144, 512, 0, 0, 7, 16}, /* DSC_V11_10BPC_8BPP */
+	{15, 15, 5632, 410, 0, 0, 7, 16}, /* DSC_V11_10BPC_10BPP */
+	/* DSC v1.1 SCR and DSC v1.2 RGB 444 */
+	{11, 11, 6144, 512, 0, 0, 3, 12}, /* DSC_V12_444_8BPC_8BPP or DSC_V11_SCR1_8BPC_8BPP */
+	{15, 15, 6144, 512, 0, 0, 7, 16}, /* DSC_V12_444_10BPC_8BPP or DSC_V11_SCR1_10BPC_8BPP */
+	{15, 15, 5632, 410, 0, 0, 7, 16}, /* DSC_V12_444_10BPC_10BPP or DSC_V11_SCR1_10BPC_10BPP */
+};
+
+/**
+ * Maps to lookup the dpu_dsc_ratio_type index used in rate control tables
+ */
+static struct dpu_dsc_table_index_lut {
+	u32 fmt;
+	u32 scr_ver;
+	u32 minor_ver;
+	u32 bpc;
+	u32 bpp;
+	u32 type;
+} dpu_dsc_index_map[] = {
+	/* DSC 1.1 formats - scr version is considered */
+	{DPU_DSC_CHROMA_444, 0, 1, 8, 8, DSC_V11_8BPC_8BPP},
+	{DPU_DSC_CHROMA_444, 0, 1, 10, 8, DSC_V11_10BPC_8BPP},
+	{DPU_DSC_CHROMA_444, 0, 1, 10, 10, DSC_V11_10BPC_10BPP},
+	{DPU_DSC_CHROMA_444, 1, 1, 8, 8, DSC_V11_SCR1_8BPC_8BPP},
+	{DPU_DSC_CHROMA_444, 1, 1, 10, 8, DSC_V11_SCR1_10BPC_8BPP},
+	{DPU_DSC_CHROMA_444, 1, 1, 10, 10, DSC_V11_SCR1_10BPC_10BPP},
+};
+
+static int _get_rc_table_index(struct drm_dsc_config *dsc, int scr_ver)
+{
+	u32 bpp, bpc, i, fmt = DPU_DSC_CHROMA_444;
+
+	if (dsc->dsc_version_major != 0x1) {
+		DPU_ERROR("unsupported major version %d\n",
+				dsc->dsc_version_major);
+		return -EINVAL;
+	}
+
+	bpc = dsc->bits_per_component;
+	bpp = DSC_BPP(*dsc);
+
+	if (dsc->native_422)
+		fmt = DPU_DSC_CHROMA_422;
+	else if (dsc->native_420)
+		fmt = DPU_DSC_CHROMA_420;
+
+
+	for (i = 0; i < ARRAY_SIZE(dpu_dsc_index_map); i++) {
+		if (dsc->dsc_version_minor == dpu_dsc_index_map[i].minor_ver &&
+				fmt ==  dpu_dsc_index_map[i].fmt &&
+				bpc == dpu_dsc_index_map[i].bpc &&
+				bpp == dpu_dsc_index_map[i].bpp &&
+				(dsc->dsc_version_minor != 0x1 ||
+					scr_ver == dpu_dsc_index_map[i].scr_ver))
+			return dpu_dsc_index_map[i].type;
+	}
+
+	DPU_ERROR("unsupported DSC v%d.%dr%d, bpc:%d, bpp:%d, fmt:0x%x\n",
+			dsc->dsc_version_major, dsc->dsc_version_minor,
+			scr_ver, bpc, bpp, fmt);
+	return -EINVAL;
+}
+
+int dpu_dsc_populate_dsc_config(struct drm_dsc_config *dsc, int scr_ver)
+{
+	int bpp, bpc;
+	struct dpu_dsc_rc_init_params_lut *rc_param_lut;
+	int i, ratio_idx;
+
+	dsc->rc_model_size = 8192;
+
+	if ((dsc->dsc_version_major == 0x1) &&
+			(dsc->dsc_version_minor == 0x1)) {
+		if (scr_ver == 0x1)
+			dsc->first_line_bpg_offset = 15;
+		else
+			dsc->first_line_bpg_offset = 12;
+	}
+
+	dsc->rc_edge_factor = 6;
+	dsc->rc_tgt_offset_high = 3;
+	dsc->rc_tgt_offset_low = 3;
+	dsc->simple_422 = 0;
+	dsc->convert_rgb = !(dsc->native_422 | dsc->native_420);
+	dsc->vbr_enable = 0;
+
+	bpp = DSC_BPP(*dsc);
+	bpc = dsc->bits_per_component;
+
+	ratio_idx = _get_rc_table_index(dsc, scr_ver);
+	if ((ratio_idx < 0) || (ratio_idx >= DSC_RATIO_TYPE_MAX))
+		return -EINVAL;
+
+
+	for (i = 0; i < DSC_NUM_BUF_RANGES - 1; i++)
+		dsc->rc_buf_thresh[i] = dpu_dsc_rc_buf_thresh[i];
+
+	for (i = 0; i < DSC_NUM_BUF_RANGES; i++) {
+		dsc->rc_range_params[i].range_min_qp =
+			dpu_dsc_rc_range_min_qp[ratio_idx][i];
+		dsc->rc_range_params[i].range_max_qp =
+			dpu_dsc_rc_range_max_qp[ratio_idx][i];
+		dsc->rc_range_params[i].range_bpg_offset =
+			dpu_dsc_rc_range_bpg[ratio_idx][i];
+	}
+
+	rc_param_lut = &dpu_dsc_rc_init_param_lut[ratio_idx];
+	dsc->rc_quant_incr_limit0 = rc_param_lut->rc_quant_incr_limit0;
+	dsc->rc_quant_incr_limit1 = rc_param_lut->rc_quant_incr_limit1;
+	dsc->initial_offset = rc_param_lut->initial_fullness_offset;
+	dsc->initial_xmit_delay = rc_param_lut->initial_xmit_delay;
+	dsc->second_line_bpg_offset = rc_param_lut->second_line_bpg_offset;
+	dsc->second_line_offset_adj = rc_param_lut->second_line_offset_adj;
+	dsc->flatness_min_qp = rc_param_lut->flatness_min_qp;
+	dsc->flatness_max_qp = rc_param_lut->flatness_max_qp;
+
+
+	dsc->line_buf_depth = bpc + 1;
+	dsc->mux_word_size = bpc > 10 ? DSC_MUX_WORD_SIZE_12_BPC : DSC_MUX_WORD_SIZE_8_10_BPC;
+
+	dsc->initial_scale_value = 8 * dsc->rc_model_size /
+			(dsc->rc_model_size - dsc->initial_offset);
+
+        return drm_dsc_compute_rc_parameters(dsc);
+}
diff --git a/drivers/gpu/drm/msm/disp/dpu1/dpu_dsc_helper.h b/drivers/gpu/drm/msm/disp/dpu1/dpu_dsc_helper.h
new file mode 100644
index 00000000..4a23e02
--- /dev/null
+++ b/drivers/gpu/drm/msm/disp/dpu1/dpu_dsc_helper.h
@@ -0,0 +1,34 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (c) 2023. Qualcomm Innovation Center, Inc. All rights reserved
+ */
+
+#ifndef __DPU_DSC_HELPER_H__
+#define __DPU_DSC_HELPER_H__
+
+#include "msm_drv.h"
+
+#define DSC_1_1_PPS_PARAMETER_SET_ELEMENTS   88
+
+/**
+ * Bits/pixel target >> 4  (removing the fractional bits)
+ * returns the integer bpp value from the drm_dsc_config struct
+ */
+#define DSC_BPP(config) ((config).bits_per_pixel >> 4)
+
+enum dpu_dsc_chroma {
+	DPU_DSC_CHROMA_444,
+	DPU_DSC_CHROMA_422,
+	DPU_DSC_CHROMA_420,
+};
+
+int dpu_dsc_populate_dsc_config(struct drm_dsc_config *dsc, int scr_ver);
+
+bool dpu_dsc_ich_reset_override_needed(bool pu_en, struct drm_dsc_config *dsc);
+
+int dpu_dsc_initial_line_calc( u32 num_active_ss_per_enc,
+				struct drm_dsc_config *dsc,
+				int enc_ip_width, int dsc_cmn_mode);
+
+#endif /* __DPU_DSC_HELPER_H__ */
+
-- 
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