From: Ondrej Jirman <megi@xxxxxx>
For panels that don't use video burst mode, hsclock should match the
pixel clock * bpp / lane exactly. This fixes display image corruption
on Pinephone Pro, which doesn't use video burst mode to drive the panel.
To simplify the addition of exact fout calculation for non-burst modes,
the code is re-organized in order to not redo the same calculation
multiple times, and to use identical algorithm for per-lane bitrate
for internal and external dphy use cases.
Signed-off-by: Ondrej Jirman <megi@xxxxxx>
---
.../gpu/drm/rockchip/dw-mipi-dsi-rockchip.c | 28 ++++++++-----------
1 file changed, 12 insertions(+), 16 deletions(-)
diff --git a/drivers/gpu/drm/rockchip/dw-mipi-dsi-rockchip.c b/drivers/gpu/drm/rockchip/dw-mipi-dsi-rockchip.c
index 4cc8ed8f4fbd..7468324872ec 100644
--- a/drivers/gpu/drm/rockchip/dw-mipi-dsi-rockchip.c
+++ b/drivers/gpu/drm/rockchip/dw-mipi-dsi-rockchip.c
@@ -548,8 +548,6 @@ dw_mipi_dsi_get_lane_mbps(void *priv_data, const struct drm_display_mode *mode,
{
struct dw_mipi_dsi_rockchip *dsi = priv_data;
int bpp;
- unsigned long mpclk, tmp;
- unsigned int target_mbps = 1000;
unsigned int max_mbps = dppa_map[ARRAY_SIZE(dppa_map) - 1].max_mbps;
unsigned long best_freq = 0;
unsigned long fvco_min, fvco_max, fin, fout;
@@ -567,30 +565,28 @@ dw_mipi_dsi_get_lane_mbps(void *priv_data, const struct drm_display_mode *mode,
return bpp;
}
- mpclk = DIV_ROUND_UP(mode->clock, MSEC_PER_SEC);
- if (mpclk) {
- /* take 1 / 0.8, since mbps must big than bandwidth of RGB */
- tmp = mpclk * (bpp / lanes) * 10 / 8;
- if (tmp < max_mbps)
- target_mbps = tmp;
- else
- DRM_DEV_ERROR(dsi->dev,
- "DPHY clock frequency is out of range\n");
+ fout = mode->clock * bpp / lanes;
+ if (mode_flags & MIPI_DSI_MODE_VIDEO_BURST)
+ fout = fout * 10 / 8;
+ fout *= MSEC_PER_SEC;
+
+ if (fout > max_mbps * USEC_PER_SEC) {
+ DRM_DEV_ERROR(dsi->dev,
+ "DPHY clock frequency is out of range\n");
+ return -EINVAL;
}
- /* for external phy only a the mipi_dphy_config is necessary */
+ /* for external phy only the mipi_dphy_config is necessary */
if (dsi->phy) {
- phy_mipi_dphy_get_default_config(mode->clock * 1000 * 10 / 8,
- bpp, lanes,
+ phy_mipi_dphy_get_default_config_for_hsclk(fout, lanes,
&dsi->phy_opts.mipi_dphy);
- dsi->lane_mbps = target_mbps;
+ dsi->lane_mbps = DIV_ROUND_UP(fout, USEC_PER_SEC);
*lane_mbps = dsi->lane_mbps;
return 0;
}
fin = clk_get_rate(dsi->pllref_clk);
- fout = target_mbps * USEC_PER_SEC;
/* constraint: 5Mhz <= Fref / N <= 40MHz */
min_prediv = DIV_ROUND_UP(fin, 40 * USEC_PER_SEC);
--
2.43.0
