[PATCH v6 01/14] drm/msm/dsi: add support for dsc data

From: Vinod Koul
Date: Mon Apr 04 2022 - 18:01:17 EST


Display Stream Compression (DSC) parameters need to be calculated. Add
helpers and struct msm_display_dsc_config in msm_drv for this
msm_display_dsc_config uses drm_dsc_config for DSC parameters.

Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@xxxxxxxxxx>
Reviewed-by: Abhinav Kumar <quic_abhinavk@xxxxxxxxxxx>
Signed-off-by: Vinod Koul <vkoul@xxxxxxxxxx>
---
drivers/gpu/drm/msm/dsi/dsi_host.c | 130 +++++++++++++++++++++++++++++
drivers/gpu/drm/msm/msm_drv.h | 6 ++
2 files changed, 136 insertions(+)

diff --git a/drivers/gpu/drm/msm/dsi/dsi_host.c b/drivers/gpu/drm/msm/dsi/dsi_host.c
index d51e70fab93d..4a8a9b31ce1d 100644
--- a/drivers/gpu/drm/msm/dsi/dsi_host.c
+++ b/drivers/gpu/drm/msm/dsi/dsi_host.c
@@ -31,6 +31,8 @@

#define DSI_RESET_TOGGLE_DELAY_MS 20

+static int dsi_populate_dsc_params(struct msm_display_dsc_config *dsc);
+
static int dsi_get_version(const void __iomem *base, u32 *major, u32 *minor)
{
u32 ver;
@@ -157,6 +159,7 @@ struct msm_dsi_host {
struct regmap *sfpb;

struct drm_display_mode *mode;
+ struct msm_display_dsc_config *dsc;

/* connected device info */
struct device_node *device_node;
@@ -1722,6 +1725,133 @@ static int dsi_host_parse_lane_data(struct msm_dsi_host *msm_host,
return -EINVAL;
}

+static u32 dsi_dsc_rc_buf_thresh[DSC_NUM_BUF_RANGES - 1] = {
+ 0x0e, 0x1c, 0x2a, 0x38, 0x46, 0x54, 0x62,
+ 0x69, 0x70, 0x77, 0x79, 0x7b, 0x7d, 0x7e
+};
+
+/* only 8bpc, 8bpp added */
+static char min_qp[DSC_NUM_BUF_RANGES] = {
+ 0, 0, 1, 1, 3, 3, 3, 3, 3, 3, 5, 5, 5, 7, 13
+};
+
+static char max_qp[DSC_NUM_BUF_RANGES] = {
+ 4, 4, 5, 6, 7, 7, 7, 8, 9, 10, 11, 12, 13, 13, 15
+};
+
+static char bpg_offset[DSC_NUM_BUF_RANGES] = {
+ 2, 0, 0, -2, -4, -6, -8, -8, -8, -10, -10, -12, -12, -12, -12
+};
+
+static int dsi_populate_dsc_params(struct msm_display_dsc_config *dsc)
+{
+ int mux_words_size;
+ int groups_per_line, groups_total;
+ int min_rate_buffer_size;
+ int hrd_delay;
+ int pre_num_extra_mux_bits, num_extra_mux_bits;
+ int slice_bits;
+ int target_bpp_x16;
+ int data;
+ int final_value, final_scale;
+ int i;
+
+ dsc->drm->rc_model_size = 8192;
+ dsc->drm->first_line_bpg_offset = 12;
+ dsc->drm->rc_edge_factor = 6;
+ dsc->drm->rc_tgt_offset_high = 3;
+ dsc->drm->rc_tgt_offset_low = 3;
+ dsc->drm->simple_422 = 0;
+ dsc->drm->convert_rgb = 1;
+ dsc->drm->vbr_enable = 0;
+
+ /* handle only bpp = bpc = 8 */
+ for (i = 0; i < DSC_NUM_BUF_RANGES - 1 ; i++)
+ dsc->drm->rc_buf_thresh[i] = dsi_dsc_rc_buf_thresh[i];
+
+ for (i = 0; i < DSC_NUM_BUF_RANGES; i++) {
+ dsc->drm->rc_range_params[i].range_min_qp = min_qp[i];
+ dsc->drm->rc_range_params[i].range_max_qp = max_qp[i];
+ dsc->drm->rc_range_params[i].range_bpg_offset = bpg_offset[i];
+ }
+
+ dsc->drm->initial_offset = 6144; /* Not bpp 12 */
+ if (dsc->drm->bits_per_pixel != 8)
+ dsc->drm->initial_offset = 2048; /* bpp = 12 */
+
+ mux_words_size = 48; /* bpc == 8/10 */
+ if (dsc->drm->bits_per_component == 12)
+ mux_words_size = 64;
+
+ dsc->drm->initial_xmit_delay = 512;
+ dsc->drm->initial_scale_value = 32;
+ dsc->drm->first_line_bpg_offset = 12;
+ dsc->drm->line_buf_depth = dsc->drm->bits_per_component + 1;
+
+ /* bpc 8 */
+ dsc->drm->flatness_min_qp = 3;
+ dsc->drm->flatness_max_qp = 12;
+ dsc->drm->rc_quant_incr_limit0 = 11;
+ dsc->drm->rc_quant_incr_limit1 = 11;
+ dsc->drm->mux_word_size = DSC_MUX_WORD_SIZE_8_10_BPC;
+
+ /* FIXME: need to call drm_dsc_compute_rc_parameters() so that rest of
+ * params are calculated
+ */
+ groups_per_line = DIV_ROUND_UP(dsc->drm->slice_width, 3);
+ dsc->drm->slice_chunk_size = dsc->drm->slice_width * dsc->drm->bits_per_pixel / 8;
+ if ((dsc->drm->slice_width * dsc->drm->bits_per_pixel) % 8)
+ dsc->drm->slice_chunk_size++;
+
+ /* rbs-min */
+ min_rate_buffer_size = dsc->drm->rc_model_size - dsc->drm->initial_offset +
+ dsc->drm->initial_xmit_delay * dsc->drm->bits_per_pixel +
+ groups_per_line * dsc->drm->first_line_bpg_offset;
+
+ hrd_delay = DIV_ROUND_UP(min_rate_buffer_size, dsc->drm->bits_per_pixel);
+
+ dsc->drm->initial_dec_delay = hrd_delay - dsc->drm->initial_xmit_delay;
+
+ dsc->drm->initial_scale_value = 8 * dsc->drm->rc_model_size /
+ (dsc->drm->rc_model_size - dsc->drm->initial_offset);
+
+ slice_bits = 8 * dsc->drm->slice_chunk_size * dsc->drm->slice_height;
+
+ groups_total = groups_per_line * dsc->drm->slice_height;
+
+ data = dsc->drm->first_line_bpg_offset * 2048;
+
+ dsc->drm->nfl_bpg_offset = DIV_ROUND_UP(data, (dsc->drm->slice_height - 1));
+
+ pre_num_extra_mux_bits = 3 * (mux_words_size + (4 * dsc->drm->bits_per_component + 4) - 2);
+
+ num_extra_mux_bits = pre_num_extra_mux_bits - (mux_words_size -
+ ((slice_bits - pre_num_extra_mux_bits) % mux_words_size));
+
+ data = 2048 * (dsc->drm->rc_model_size - dsc->drm->initial_offset + num_extra_mux_bits);
+ dsc->drm->slice_bpg_offset = DIV_ROUND_UP(data, groups_total);
+
+ /* bpp * 16 + 0.5 */
+ data = dsc->drm->bits_per_pixel * 16;
+ data *= 2;
+ data++;
+ data /= 2;
+ target_bpp_x16 = data;
+
+ data = (dsc->drm->initial_xmit_delay * target_bpp_x16) / 16;
+ final_value = dsc->drm->rc_model_size - data + num_extra_mux_bits;
+ dsc->drm->final_offset = final_value;
+
+ final_scale = 8 * dsc->drm->rc_model_size / (dsc->drm->rc_model_size - final_value);
+
+ data = (final_scale - 9) * (dsc->drm->nfl_bpg_offset + dsc->drm->slice_bpg_offset);
+ dsc->drm->scale_increment_interval = (2048 * dsc->drm->final_offset) / data;
+
+ dsc->drm->scale_decrement_interval = groups_per_line / (dsc->drm->initial_scale_value - 8);
+
+ return 0;
+}
+
static int dsi_host_parse_dt(struct msm_dsi_host *msm_host)
{
struct device *dev = &msm_host->pdev->dev;
diff --git a/drivers/gpu/drm/msm/msm_drv.h b/drivers/gpu/drm/msm/msm_drv.h
index 9f68aa685ed7..57aee75f5022 100644
--- a/drivers/gpu/drm/msm/msm_drv.h
+++ b/drivers/gpu/drm/msm/msm_drv.h
@@ -30,6 +30,7 @@
#include <drm/drm_plane_helper.h>
#include <drm/drm_probe_helper.h>
#include <drm/drm_fb_helper.h>
+#include <drm/drm_dsc.h>
#include <drm/msm_drm.h>
#include <drm/drm_gem.h>

@@ -116,6 +117,11 @@ struct msm_drm_thread {
struct kthread_worker *worker;
};

+/* DSC config */
+struct msm_display_dsc_config {
+ struct drm_dsc_config *drm;
+};
+
struct msm_drm_private {

struct drm_device *dev;
--
2.34.1