[RFC PATCH 07/10] drm/bridge: ps8640: require manual DSI power control

Dmitry Baryshkov
2023-10-16T16:57:06Z

The Parade PS8640 bridge will fail to start if the DSI link is enabled
when the bridge is being reset / powered up (even to the LP-11 state).
To ensure that the DSI link is powered down, require manual control over
the DSI link state.

Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
---
drivers/gpu/drm/bridge/parade-ps8640.c | 14 +++++++++++++-
1 file changed, 13 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/bridge/parade-ps8640.c b/drivers/gpu/drm/bridge/parade-ps8640.c
index 8161b1a1a4b1..6c5daaa70cb7 100644
--- a/drivers/gpu/drm/bridge/parade-ps8640.c
+++ b/drivers/gpu/drm/bridge/parade-ps8640.c
@@ -458,6 +458,10 @@ static void ps8640_atomic_pre_enable(struct drm_bridge *bridge,

ps8640_bridge_vdo_control(ps_bridge, ENABLE);

+ ret = mipi_dsi_host_power_up(ps_bridge->dsi->host);
+ if (ret < 0)
+ dev_warn(dev, "failed to power up DSI host: %d\n", ret);
+
ps_bridge->pre_enabled = true;
}

@@ -468,6 +472,8 @@ static void ps8640_atomic_post_disable(struct drm_bridge *bridge,

ps_bridge->pre_enabled = false;

+ mipi_dsi_host_power_down(ps_bridge->dsi->host);
+
ps8640_bridge_vdo_control(ps_bridge, DISABLE);
pm_runtime_put_sync_suspend(&ps_bridge->page[PAGE0_DP_CNTL]->dev);
}
@@ -562,6 +568,11 @@ static int ps8640_bridge_get_dsi_resources(struct device *dev, struct ps8640 *ps
if (!host)
return -EPROBE_DEFER;

+ if (!mipi_dsi_host_power_control_available(host)) {
+ dev_err(dev, "MIPI DSI host doesn't provide tight power control\n");
+ return -ENODEV;
+ }
+
dsi = devm_mipi_dsi_device_register_full(dev, host, &info);
if (IS_ERR(dsi)) {
dev_err(dev, "failed to create dsi device\n");
@@ -572,7 +583,8 @@ static int ps8640_bridge_get_dsi_resources(struct device *dev, struct ps8640 *ps

dsi->host = host;
dsi->mode_flags = MIPI_DSI_MODE_VIDEO |
- MIPI_DSI_MODE_VIDEO_SYNC_PULSE;
+ MIPI_DSI_MODE_VIDEO_SYNC_PULSE |
+ MIPI_DSI_MANUAL_POWERUP;
dsi->format = MIPI_DSI_FMT_RGB888;
dsi->lanes = NUM_MIPI_LANES;

--
2.42.0