The pixel clock is optional. When available, it offers a better
preciseness for timing computations and allows to reduce the extra dsi
bandwidth in burst mode (from ~20% to ~10-12%, hw platform dependant).
Reviewed-by: Andrzej Hajda <a.hajda@xxxxxxxxxxx>
Signed-off-by: Philippe Cornu <philippe.cornu@xxxxxx>
---
Changes in v3: Simplify px_clk probing thanks to Andrzej Hajda comments
Changes in v2: Improve px_clk probing in case of ENOENT dt returned value
(thanks to Philipp Zabel & Andrzej Hajda comments)
drivers/gpu/drm/bridge/synopsys/dw-mipi-dsi.c | 25 +++++++++++++++++++------
1 file changed, 19 insertions(+), 6 deletions(-)
diff --git a/drivers/gpu/drm/bridge/synopsys/dw-mipi-dsi.c b/drivers/gpu/drm/bridge/synopsys/dw-mipi-dsi.c
index ed8af32f8e52..9fb35385c348 100644
--- a/drivers/gpu/drm/bridge/synopsys/dw-mipi-dsi.c
+++ b/drivers/gpu/drm/bridge/synopsys/dw-mipi-dsi.c
@@ -217,6 +217,7 @@ struct dw_mipi_dsi {
void __iomem *base;
struct clk *pclk;
+ struct clk *px_clk;
unsigned int lane_mbps; /* per lane */
u32 channel;
@@ -703,24 +704,28 @@ static void dw_mipi_dsi_bridge_mode_set(struct drm_bridge *bridge,
struct dw_mipi_dsi *dsi = bridge_to_dsi(bridge);
const struct dw_mipi_dsi_phy_ops *phy_ops = dsi->plat_data->phy_ops;
void *priv_data = dsi->plat_data->priv_data;
+ struct drm_display_mode px_clk_mode = *mode;
int ret;
clk_prepare_enable(dsi->pclk);
- ret = phy_ops->get_lane_mbps(priv_data, mode, dsi->mode_flags,
+ if (dsi->px_clk)
+ px_clk_mode.clock = clk_get_rate(dsi->px_clk) / 1000;
+
+ ret = phy_ops->get_lane_mbps(priv_data, &px_clk_mode, dsi->mode_flags,
dsi->lanes, dsi->format, &dsi->lane_mbps);
if (ret)
DRM_DEBUG_DRIVER("Phy get_lane_mbps() failed\n");
pm_runtime_get_sync(dsi->dev);
dw_mipi_dsi_init(dsi);
- dw_mipi_dsi_dpi_config(dsi, mode);
+ dw_mipi_dsi_dpi_config(dsi, &px_clk_mode);
dw_mipi_dsi_packet_handler_config(dsi);
dw_mipi_dsi_video_mode_config(dsi);
- dw_mipi_dsi_video_packet_config(dsi, mode);
+ dw_mipi_dsi_video_packet_config(dsi, &px_clk_mode);
dw_mipi_dsi_command_mode_config(dsi);
- dw_mipi_dsi_line_timer_config(dsi, mode);
- dw_mipi_dsi_vertical_timing_config(dsi, mode);
+ dw_mipi_dsi_line_timer_config(dsi, &px_clk_mode);
+ dw_mipi_dsi_vertical_timing_config(dsi, &px_clk_mode);
dw_mipi_dsi_dphy_init(dsi);
dw_mipi_dsi_dphy_timing_config(dsi);
@@ -734,7 +739,7 @@ static void dw_mipi_dsi_bridge_mode_set(struct drm_bridge *bridge,
dw_mipi_dsi_dphy_enable(dsi);
- dw_mipi_dsi_wait_for_two_frames(mode);
+ dw_mipi_dsi_wait_for_two_frames(&px_clk_mode);
/* Switch to cmd mode for panel-bridge pre_enable & panel prepare */
dw_mipi_dsi_set_mode(dsi, 0);
@@ -828,6 +833,14 @@ __dw_mipi_dsi_probe(struct platform_device *pdev,
return ERR_PTR(ret);
}
+ dsi->px_clk = devm_clk_get(dev, "px_clk");
+ if (IS_ERR(dsi->px_clk)) {
+ ret = PTR_ERR(dsi->px_clk);
+ if (ret != ENOENT)
+ dev_err(dev, "Unable to get opt. px_clk: %d\n", ret);
+ dsi->px_clk = NULL;
+ }
+
/*
* Note that the reset was not defined in the initial device tree, so
* we have to be prepared for it not being found.
--
2.15.1
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