[PATCH 3/3] drm/vc4: Make DSI call into the bridge after the DSI link is enabled.

From: Eric Anholt
Date: Wed Jun 06 2018 - 15:04:42 EST


This allows panels or bridges that need to send DSI commands during
pre_enable() to successfully send them. We delay DISP0 (aka the
actual display) enabling until after pre_enable so that pixels aren't
streaming before then.

Signed-off-by: Eric Anholt <eric@xxxxxxxxxx>
---
drivers/gpu/drm/vc4/vc4_dsi.c | 37 +++++++++++++++++++++--------------
1 file changed, 22 insertions(+), 15 deletions(-)

diff --git a/drivers/gpu/drm/vc4/vc4_dsi.c b/drivers/gpu/drm/vc4/vc4_dsi.c
index 8aa897835118..02cbfcc3cc4b 100644
--- a/drivers/gpu/drm/vc4/vc4_dsi.c
+++ b/drivers/gpu/drm/vc4/vc4_dsi.c
@@ -814,7 +814,9 @@ static void vc4_dsi_encoder_disable(struct drm_encoder *encoder)
struct vc4_dsi *dsi = vc4_encoder->dsi;
struct device *dev = &dsi->pdev->dev;

+ drm_bridge_disable(dsi->bridge);
vc4_dsi_ulps(dsi, true);
+ drm_bridge_post_disable(dsi->bridge);

clk_disable_unprepare(dsi->pll_phy_clock);
clk_disable_unprepare(dsi->escape_clock);
@@ -1089,21 +1091,6 @@ static void vc4_dsi_encoder_enable(struct drm_encoder *encoder)
/* Display reset sequence timeout */
DSI_PORT_WRITE(PR_TO_CNT, 100000);

- if (dsi->mode_flags & MIPI_DSI_MODE_VIDEO) {
- DSI_PORT_WRITE(DISP0_CTRL,
- VC4_SET_FIELD(dsi->divider,
- DSI_DISP0_PIX_CLK_DIV) |
- VC4_SET_FIELD(dsi->format, DSI_DISP0_PFORMAT) |
- VC4_SET_FIELD(DSI_DISP0_LP_STOP_PERFRAME,
- DSI_DISP0_LP_STOP_CTRL) |
- DSI_DISP0_ST_END |
- DSI_DISP0_ENABLE);
- } else {
- DSI_PORT_WRITE(DISP0_CTRL,
- DSI_DISP0_COMMAND_MODE |
- DSI_DISP0_ENABLE);
- }
-
/* Set up DISP1 for transferring long command payloads through
* the pixfifo.
*/
@@ -1128,6 +1115,25 @@ static void vc4_dsi_encoder_enable(struct drm_encoder *encoder)

vc4_dsi_ulps(dsi, false);

+ drm_bridge_pre_enable(dsi->bridge);
+
+ if (dsi->mode_flags & MIPI_DSI_MODE_VIDEO) {
+ DSI_PORT_WRITE(DISP0_CTRL,
+ VC4_SET_FIELD(dsi->divider,
+ DSI_DISP0_PIX_CLK_DIV) |
+ VC4_SET_FIELD(dsi->format, DSI_DISP0_PFORMAT) |
+ VC4_SET_FIELD(DSI_DISP0_LP_STOP_PERFRAME,
+ DSI_DISP0_LP_STOP_CTRL) |
+ DSI_DISP0_ST_END |
+ DSI_DISP0_ENABLE);
+ } else {
+ DSI_PORT_WRITE(DISP0_CTRL,
+ DSI_DISP0_COMMAND_MODE |
+ DSI_DISP0_ENABLE);
+ }
+
+ drm_bridge_enable(dsi->bridge);
+
if (debug_dump_regs) {
DRM_INFO("DSI regs after:\n");
vc4_dsi_dump_regs(dsi);
@@ -1639,6 +1645,7 @@ static int vc4_dsi_bind(struct device *dev, struct device *master, void *data)
dev_err(dev, "bridge attach failed: %d\n", ret);
return ret;
}
+ dsi->bridge->disable_midlayer_calls = true;

pm_runtime_enable(dev);

--
2.17.0