[PATCH v2 5/6] drm/msm/dsi: support DSC configurations with slice_per_pkt > 1

Jonathan Marek
2023-11-14T23:00:56Z

Add a dsc_slice_per_pkt field to mipi_dsi_device struct and the necessary
changes to msm driver to support this field.

Note that the removed "pkt_per_line = slice_per_intf * slice_per_pkt"
comment is incorrect.

Signed-off-by: Jonathan Marek <jonathan@marek.ca>
---
drivers/gpu/drm/msm/dsi/dsi_host.c | 25 ++++++++++---------------
include/drm/drm_mipi_dsi.h | 1 +
2 files changed, 11 insertions(+), 15 deletions(-)

diff --git a/drivers/gpu/drm/msm/dsi/dsi_host.c b/drivers/gpu/drm/msm/dsi/dsi_host.c
index 842765063b1b..892a463a7e03 100644
--- a/drivers/gpu/drm/msm/dsi/dsi_host.c
+++ b/drivers/gpu/drm/msm/dsi/dsi_host.c
@@ -161,6 +161,7 @@ struct msm_dsi_host {

struct drm_display_mode *mode;
struct drm_dsc_config *dsc;
+ unsigned int dsc_slice_per_pkt;

/* connected device info */
unsigned int channel;
@@ -857,17 +858,10 @@ static void dsi_update_dsc_timing(struct msm_dsi_host *msm_host, bool is_cmd_mod
slice_per_intf = msm_dsc_get_slices_per_intf(dsc, hdisplay);

total_bytes_per_intf = dsc->slice_chunk_size * slice_per_intf;
- bytes_per_pkt = dsc->slice_chunk_size; /* * slice_per_pkt; */
+ bytes_per_pkt = dsc->slice_chunk_size * msm_host->dsc_slice_per_pkt;

eol_byte_num = total_bytes_per_intf % 3;
-
- /*
- * Typically, pkt_per_line = slice_per_intf * slice_per_pkt.
- *
- * Since the current driver only supports slice_per_pkt = 1,
- * pkt_per_line will be equal to slice per intf for now.
- */
- pkt_per_line = slice_per_intf;
+ pkt_per_line = slice_per_intf / msm_host->dsc_slice_per_pkt;

if (is_cmd_mode) /* packet data type */
reg = DSI_COMMAND_COMPRESSION_MODE_CTRL_STREAM0_DATATYPE(MIPI_DSI_DCS_LONG_WRITE);
@@ -1004,12 +998,8 @@ static void dsi_timing_setup(struct msm_dsi_host *msm_host, bool is_bonded_dsi)
else
/*
* When DSC is enabled, WC = slice_chunk_size * slice_per_pkt + 1.
- * Currently, the driver only supports default value of slice_per_pkt = 1
- *
- * TODO: Expand mipi_dsi_device struct to hold slice_per_pkt info
- * and adjust DSC math to account for slice_per_pkt.
*/
- wc = msm_host->dsc->slice_chunk_size + 1;
+ wc = msm_host->dsc->slice_chunk_size * msm_host->dsc_slice_per_pkt + 1;

dsi_write(msm_host, REG_DSI_CMD_MDP_STREAM0_CTRL,
DSI_CMD_MDP_STREAM0_CTRL_WORD_COUNT(wc) |
@@ -1636,8 +1626,13 @@ static int dsi_host_attach(struct mipi_dsi_host *host,
msm_host->lanes = dsi->lanes;
msm_host->format = dsi->format;
msm_host->mode_flags = dsi->mode_flags;
- if (dsi->dsc)
+ if (dsi->dsc) {
msm_host->dsc = dsi->dsc;
+ msm_host->dsc_slice_per_pkt = dsi->dsc_slice_per_pkt;
+ /* for backwards compatibility, assume 1 if not set */
+ if (!msm_host->dsc_slice_per_pkt)
+ msm_host->dsc_slice_per_pkt = 1;
+ }

/* Some gpios defined in panel DT need to be controlled by host */
ret = dsi_host_init_panel_gpios(msm_host, &dsi->dev);
diff --git a/include/drm/drm_mipi_dsi.h b/include/drm/drm_mipi_dsi.h
index c9df0407980c..3e32fa52d94b 100644
--- a/include/drm/drm_mipi_dsi.h
+++ b/include/drm/drm_mipi_dsi.h
@@ -193,6 +193,7 @@ struct mipi_dsi_device {
unsigned long hs_rate;
unsigned long lp_rate;
struct drm_dsc_config *dsc;
+ unsigned int dsc_slice_per_pkt;
};

#define MIPI_DSI_MODULE_PREFIX "mipi-dsi:"
--
2.26.1