diff --git a/Documentation/gpu/drm-kms-helpers.rst b/Documentation/gpu/drm-kms-helpers.rst
index 4b4dc236ef6f2443294818cffed0c6032ef005be..b422eb8edf1627baba10a231560eca754e31e846 100644
--- a/Documentation/gpu/drm-kms-helpers.rst
+++ b/Documentation/gpu/drm-kms-helpers.rst
@@ -232,6 +232,18 @@ MIPI DSI Helper Functions Reference
.. kernel-doc:: drivers/gpu/drm/drm_mipi_dsi.c
:export:
+Display Stream Compression Helper Functions Reference
+=====================================================
+
+.. kernel-doc:: drivers/gpu/drm/drm_dsc.c
+ :doc: dsc helpers
+
+.. kernel-doc:: include/drm/drm_dsc.h
+ :internal:
+
+.. kernel-doc:: drivers/gpu/drm/drm_dsc.c
+ :export:
+
Output Probing Helper Functions Reference
=========================================
diff --git a/drivers/gpu/drm/Makefile b/drivers/gpu/drm/Makefile
index 7f3be3506057af368c84a6584b298930166c49c3..65a643da48d7ab858e975a5a549773b59ec482c3 100644
--- a/drivers/gpu/drm/Makefile
+++ b/drivers/gpu/drm/Makefile
@@ -32,7 +32,7 @@ drm-$(CONFIG_AGP) += drm_agpsupport.o
drm-$(CONFIG_DEBUG_FS) += drm_debugfs.o drm_debugfs_crc.o
drm-$(CONFIG_DRM_LOAD_EDID_FIRMWARE) += drm_edid_load.o
-drm_kms_helper-y := drm_crtc_helper.o drm_dp_helper.o drm_probe_helper.o \
+drm_kms_helper-y := drm_crtc_helper.o drm_dp_helper.o drm_dsc.o drm_probe_helper.o \
drm_plane_helper.o drm_dp_mst_topology.o drm_atomic_helper.o \
drm_kms_helper_common.o drm_dp_dual_mode_helper.o \
drm_simple_kms_helper.o drm_modeset_helper.o \
diff --git a/drivers/gpu/drm/drm_dsc.c b/drivers/gpu/drm/drm_dsc.c
new file mode 100644
index 0000000000000000000000000000000000000000..bc2b23adb072ab6755bbcd1a83b511d652ffb996
--- /dev/null
+++ b/drivers/gpu/drm/drm_dsc.c
@@ -0,0 +1,228 @@
+// SPDX-License-Identifier: MIT
+/*
+ * Copyright © 2018 Intel Corp
+ *
+ * Author:
+ * Manasi Navare <manasi.d.navare@intel.com>
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/errno.h>
+#include <linux/byteorder/generic.h>
+#include <drm/drm_dp_helper.h>
+#include <drm/drm_dsc.h>
+
+/**
+ * DOC: dsc helpers
+ *
+ * These functions contain some common logic and helpers to deal with VESA
+ * Display Stream Compression standard required for DSC on Display Port/eDP or
+ * MIPI display interfaces.
+ */
+
+/**
+ * drm_dsc_dp_pps_header_init() - Initializes the PPS Header
+ * for DisplayPort as per the DP 1.4 spec.
+ * @pps_sdp: Secondary data packet for DSC Picture Parameter Set
+ */
+void drm_dsc_dp_pps_header_init(struct drm_dsc_pps_infoframe *pps_sdp)
+{
+ memset(&pps_sdp->pps_header, 0, sizeof(pps_sdp->pps_header));
+
+ pps_sdp->pps_header.HB1 = DP_SDP_PPS;
+ pps_sdp->pps_header.HB2 = DP_SDP_PPS_HEADER_PAYLOAD_BYTES_MINUS_1;
+}
+EXPORT_SYMBOL(drm_dsc_dp_pps_header_init);
+
+/**
+ * drm_dsc_pps_infoframe_pack() - Populates the DSC PPS infoframe
+ * using the DSC configuration parameters in the order expected
+ * by the DSC Display Sink device. For the DSC, the sink device
+ * expects the PPS payload in the big endian format for the fields
+ * that span more than 1 byte.
+ *
+ * @pps_sdp:
+ * Secondary data packet for DSC Picture Parameter Set
+ * @dsc_cfg:
+ * DSC Configuration data filled by driver
+ */
+void drm_dsc_pps_infoframe_pack(struct drm_dsc_pps_infoframe *pps_sdp,
+ const struct drm_dsc_config *dsc_cfg)
+{
+ int i;
+
+ /* Protect against someone accidently changing struct size */
+ BUILD_BUG_ON(sizeof(pps_sdp->pps_payload) !=
+ DP_SDP_PPS_HEADER_PAYLOAD_BYTES_MINUS_1 + 1);
+
+ memset(&pps_sdp->pps_payload, 0, sizeof(pps_sdp->pps_payload));
+
+ /* PPS 0 */
+ pps_sdp->pps_payload.dsc_version =
+ dsc_cfg->dsc_version_minor |
+ dsc_cfg->dsc_version_major << DSC_PPS_VERSION_MAJOR_SHIFT;
+
+ /* PPS 1, 2 is 0 */
+
+ /* PPS 3 */
+ pps_sdp->pps_payload.pps_3 =
+ dsc_cfg->line_buf_depth |
+ dsc_cfg->bits_per_component << DSC_PPS_BPC_SHIFT;
+
+ /* PPS 4 */
+ pps_sdp->pps_payload.pps_4 =
+ ((dsc_cfg->bits_per_pixel & DSC_PPS_BPP_HIGH_MASK) >>
+ DSC_PPS_MSB_SHIFT) |
+ dsc_cfg->vbr_enable << DSC_PPS_VBR_EN_SHIFT |
+ dsc_cfg->enable422 << DSC_PPS_SIMPLE422_SHIFT |
+ dsc_cfg->convert_rgb << DSC_PPS_CONVERT_RGB_SHIFT |
+ dsc_cfg->block_pred_enable << DSC_PPS_BLOCK_PRED_EN_SHIFT;
+
+ /* PPS 5 */
+ pps_sdp->pps_payload.bits_per_pixel_low =
+ (dsc_cfg->bits_per_pixel & DSC_PPS_LSB_MASK);
+
+ /*
+ * The DSC panel expects the PPS packet to have big endian format
+ * for data spanning 2 bytes. Use a macro cpu_to_be16() to convert
+ * to big endian format. If format is little endian, it will swap
+ * bytes to convert to Big endian else keep it unchanged.
+ */
+
+ /* PPS 6, 7 */
+ pps_sdp->pps_payload.pic_height = cpu_to_be16(dsc_cfg->pic_height);
+
+ /* PPS 8, 9 */
+ pps_sdp->pps_payload.pic_width = cpu_to_be16(dsc_cfg->pic_width);
+
+ /* PPS 10, 11 */
+ pps_sdp->pps_payload.slice_height = cpu_to_be16(dsc_cfg->slice_height);
+
+ /* PPS 12, 13 */
+ pps_sdp->pps_payload.slice_width = cpu_to_be16(dsc_cfg->slice_width);
+
+ /* PPS 14, 15 */
+ pps_sdp->pps_payload.chunk_size = cpu_to_be16(dsc_cfg->slice_chunk_size);
+
+ /* PPS 16 */
+ pps_sdp->pps_payload.initial_xmit_delay_high =
+ ((dsc_cfg->initial_xmit_delay &
+ DSC_PPS_INIT_XMIT_DELAY_HIGH_MASK) >>
+ DSC_PPS_MSB_SHIFT);
+
+ /* PPS 17 */
+ pps_sdp->pps_payload.initial_xmit_delay_low =
+ (dsc_cfg->initial_xmit_delay & DSC_PPS_LSB_MASK);
+
+ /* PPS 18, 19 */
+ pps_sdp->pps_payload.initial_dec_delay =
+ cpu_to_be16(dsc_cfg->initial_dec_delay);
+
+ /* PPS 20 is 0 */
+
+ /* PPS 21 */
+ pps_sdp->pps_payload.initial_scale_value =
+ dsc_cfg->initial_scale_value;
+
+ /* PPS 22, 23 */
+ pps_sdp->pps_payload.scale_increment_interval =
+ cpu_to_be16(dsc_cfg->scale_increment_interval);
+
+ /* PPS 24 */
+ pps_sdp->pps_payload.scale_decrement_interval_high =
+ ((dsc_cfg->scale_decrement_interval &
+ DSC_PPS_SCALE_DEC_INT_HIGH_MASK) >>
+ DSC_PPS_MSB_SHIFT);
+
+ /* PPS 25 */
+ pps_sdp->pps_payload.scale_decrement_interval_low =
+ (dsc_cfg->scale_decrement_interval & DSC_PPS_LSB_MASK);
+
+ /* PPS 26[7:0], PPS 27[7:5] RESERVED */
+
+ /* PPS 27 */
+ pps_sdp->pps_payload.first_line_bpg_offset =
+ dsc_cfg->first_line_bpg_offset;
+
+ /* PPS 28, 29 */
+ pps_sdp->pps_payload.nfl_bpg_offset =
+ cpu_to_be16(dsc_cfg->nfl_bpg_offset);
+
+ /* PPS 30, 31 */
+ pps_sdp->pps_payload.slice_bpg_offset =
+ cpu_to_be16(dsc_cfg->slice_bpg_offset);
+
+ /* PPS 32, 33 */
+ pps_sdp->pps_payload.initial_offset =
+ cpu_to_be16(dsc_cfg->initial_offset);
+
+ /* PPS 34, 35 */
+ pps_sdp->pps_payload.final_offset = cpu_to_be16(dsc_cfg->final_offset);
+
+ /* PPS 36 */
+ pps_sdp->pps_payload.flatness_min_qp = dsc_cfg->flatness_min_qp;
+
+ /* PPS 37 */
+ pps_sdp->pps_payload.flatness_max_qp = dsc_cfg->flatness_max_qp;
+
+ /* PPS 38, 39 */
+ pps_sdp->pps_payload.rc_model_size =
+ cpu_to_be16(DSC_RC_MODEL_SIZE_CONST);
+
+ /* PPS 40 */
+ pps_sdp->pps_payload.rc_edge_factor = DSC_RC_EDGE_FACTOR_CONST;
+
+ /* PPS 41 */
+ pps_sdp->pps_payload.rc_quant_incr_limit0 =
+ dsc_cfg->rc_quant_incr_limit0;
+
+ /* PPS 42 */
+ pps_sdp->pps_payload.rc_quant_incr_limit1 =
+ dsc_cfg->rc_quant_incr_limit1;
+
+ /* PPS 43 */
+ pps_sdp->pps_payload.rc_tgt_offset = DSC_RC_TGT_OFFSET_LO_CONST |
+ DSC_RC_TGT_OFFSET_HI_CONST << DSC_PPS_RC_TGT_OFFSET_HI_SHIFT;
+
+ /* PPS 44 - 57 */
+ for (i = 0; i < DSC_NUM_BUF_RANGES - 1; i++)
+ pps_sdp->pps_payload.rc_buf_thresh[i] =
+ dsc_cfg->rc_buf_thresh[i];
+
+ /* PPS 58 - 87 */
+ /*
+ * For DSC sink programming the RC Range parameter fields
+ * are as follows: Min_qp[15:11], max_qp[10:6], offset[5:0]
+ */
+ for (i = 0; i < DSC_NUM_BUF_RANGES; i++) {
+ pps_sdp->pps_payload.rc_range_parameters[i] =
+ ((dsc_cfg->rc_range_params[i].range_min_qp <<
+ DSC_PPS_RC_RANGE_MINQP_SHIFT) |
+ (dsc_cfg->rc_range_params[i].range_max_qp <<
+ DSC_PPS_RC_RANGE_MAXQP_SHIFT) |
+ (dsc_cfg->rc_range_params[i].range_bpg_offset));
+ pps_sdp->pps_payload.rc_range_parameters[i] =
+ cpu_to_be16(pps_sdp->pps_payload.rc_range_parameters[i]);
+ }
+
+ /* PPS 88 */
+ pps_sdp->pps_payload.native_422_420 = dsc_cfg->native_422 |
+ dsc_cfg->native_420 << DSC_PPS_NATIVE_420_SHIFT;
+
+ /* PPS 89 */
+ pps_sdp->pps_payload.second_line_bpg_offset =
+ dsc_cfg->second_line_bpg_offset;
+
+ /* PPS 90, 91 */
+ pps_sdp->pps_payload.nsl_bpg_offset =
+ cpu_to_be16(dsc_cfg->nsl_bpg_offset);
+
+ /* PPS 92, 93 */
+ pps_sdp->pps_payload.second_line_offset_adj =
+ cpu_to_be16(dsc_cfg->second_line_offset_adj);
+
+ /* PPS 94 - 127 are O */
+}
+EXPORT_SYMBOL(drm_dsc_pps_infoframe_pack);
diff --git a/include/drm/drm_dsc.h b/include/drm/drm_dsc.h
index b88e31bd9da778c8453917114ce0bcf4450bba08..52e57ceaff80050c2fd546c573442c182609898a 100644
--- a/include/drm/drm_dsc.h
+++ b/include/drm/drm_dsc.h
@@ -24,6 +24,23 @@
#define DSC_RC_TGT_OFFSET_HI_CONST 3
#define DSC_RC_TGT_OFFSET_LO_CONST 3
+/* DSC PPS constants and macros */
+#define DSC_PPS_VERSION_MAJOR_SHIFT 4
+#define DSC_PPS_BPC_SHIFT 4
+#define DSC_PPS_MSB_SHIFT 8
+#define DSC_PPS_LSB_MASK (0xFF << 0)
+#define DSC_PPS_BPP_HIGH_MASK (0x3 << 8)
+#define DSC_PPS_VBR_EN_SHIFT 2
+#define DSC_PPS_SIMPLE422_SHIFT 3
+#define DSC_PPS_CONVERT_RGB_SHIFT 4
+#define DSC_PPS_BLOCK_PRED_EN_SHIFT 5
+#define DSC_PPS_INIT_XMIT_DELAY_HIGH_MASK (0x3 << 8)
+#define DSC_PPS_SCALE_DEC_INT_HIGH_MASK (0xF << 8)
+#define DSC_PPS_RC_TGT_OFFSET_HI_SHIFT 4
+#define DSC_PPS_RC_RANGE_MINQP_SHIFT 11
+#define DSC_PPS_RC_RANGE_MAXQP_SHIFT 6
+#define DSC_PPS_NATIVE_420_SHIFT 1
+
/* Configuration for a single Rate Control model range */
struct drm_dsc_rc_range_parameters {
/* Min Quantization Parameters allowed for this range */
@@ -458,4 +475,8 @@ struct drm_dsc_pps_infoframe {
struct drm_dsc_picture_parameter_set pps_payload;
} __packed;
+void drm_dsc_dp_pps_header_init(struct drm_dsc_pps_infoframe *pps_sdp);
+void drm_dsc_pps_infoframe_pack(struct drm_dsc_pps_infoframe *pps_sdp,
+ const struct drm_dsc_config *dsc_cfg);
+
#endif /* _DRM_DSC_H_ */