[PATCH v7 1/3] drm: bridge: samsung-dsim: enter display mode in the enable() callback

[Dario Binacchi]

The synaptics-r63353 (panel-bridge) can only be configured in command mode.
So, samsung-dsim (bridge) must not be in display mode during the
prepare()/unprepare() of the panel-bridge. Setting the
"pre_enable_prev_first" flag to true allows the prepare() of the
panel-bridge to be called between the pre_enabled() and enabled() of the
bridge. So, the bridge can enter display mode only in the enabled().
The unprepare() of the panel-bridge is instead called between the disable()
and post_disable() of the bridge. So, the disable() must exit the display
mode (i .e. enter command mode) to allow the panel-bridge to receive DSI
commands.

samsung_dsim_atomic_pre_enable   -> command mode
r63353_panel_prepare             -> send DSI commands
samsung_dsim_atomic_enable       -> enter display mode

samsung_dsim_atomic_disable      -> exit display mode (command mode)
r63353_panel_unprepare           -> send DSI commands
samsung_dsim_atomic_post_disable

Co-developed-by: Michael Trimarchi <mich...@amarulasolutions.com>
Signed-off-by: Michael Trimarchi <mich...@amarulasolutions.com>
Signed-off-by: Dario Binacchi <dario.binac...@amarulasolutions.com>
---

(no changes since v1)

 drivers/gpu/drm/bridge/samsung-dsim.c | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/bridge/samsung-dsim.c 
b/drivers/gpu/drm/bridge/samsung-dsim.c
index be5914caa17d..15bf05b2bbe4 100644
--- a/drivers/gpu/drm/bridge/samsung-dsim.c
+++ b/drivers/gpu/drm/bridge/samsung-dsim.c
@@ -1494,7 +1494,6 @@ static void samsung_dsim_atomic_pre_enable(struct 
drm_bridge *bridge,
                        return;
 
                samsung_dsim_set_display_mode(dsi);
-               samsung_dsim_set_display_enable(dsi, true);
        }
 }
 
@@ -1507,6 +1506,7 @@ static void samsung_dsim_atomic_enable(struct drm_bridge 
*bridge,
                samsung_dsim_set_display_mode(dsi);
                samsung_dsim_set_display_enable(dsi, true);
        } else {
+               samsung_dsim_set_display_enable(dsi, true);
                samsung_dsim_set_stop_state(dsi, false);
        }
 
@@ -1524,6 +1524,8 @@ static void samsung_dsim_atomic_disable(struct drm_bridge 
*bridge,
        if (!samsung_dsim_hw_is_exynos(dsi->plat_data->hw_type))
                samsung_dsim_set_stop_state(dsi, true);
 
+       samsung_dsim_set_display_enable(dsi, false);
+
        dsi->state &= ~DSIM_STATE_VIDOUT_AVAILABLE;
 }
 
@@ -1532,7 +1534,8 @@ static void samsung_dsim_atomic_post_disable(struct 
drm_bridge *bridge,
 {
        struct samsung_dsim *dsi = bridge_to_dsi(bridge);
 
-       samsung_dsim_set_display_enable(dsi, false);
+       if (!samsung_dsim_hw_is_exynos(dsi->plat_data->hw_type))
+               samsung_dsim_set_stop_state(dsi, true);
 
        dsi->state &= ~DSIM_STATE_ENABLED;
        pm_runtime_put_sync(dsi->dev);
-- 
2.43.0