drm/tegra: dsi: Reset across ->exit()/->init()

This allows a DRM driver unload/reload cycle to completely reset the DSI
controller and may help in situations where it's broken.

Signed-off-by: Thierry Reding <treding@nvidia.com>

1 files changed, 14 insertions, 13 deletions

diff --git a/drivers/gpu/drm/tegra/dsi.c b/drivers/gpu/drm/tegra/dsi.c
index 60b802205546..748727bc175b 100644
--- a/drivers/gpu/drm/tegra/dsi.c
+++ b/drivers/gpu/drm/tegra/dsi.c
@@ -948,6 +948,14 @@ static int tegra_dsi_init(struct host1x_client *client)
         struct tegra_dsi *dsi = host1x_client_to_dsi(client);
         int err;
 
+        reset_control_deassert(dsi->rst);
+
+        err = tegra_dsi_pad_calibrate(dsi);
+        if (err < 0) {
+                dev_err(dsi->dev, "MIPI calibration failed: %d\n", err);
+                goto reset;
+        }
+
         /* Gangsters must not register their own outputs. */
         if (!dsi->master) {
                 dsi->output.type = TEGRA_OUTPUT_DSI;
@@ -968,6 +976,10 @@ static int tegra_dsi_init(struct host1x_client *client)
         }
 
         return 0;
+
+reset:
+        reset_control_assert(dsi->rst);
+        return err;
 }
 
 static int tegra_dsi_exit(struct host1x_client *client)
@@ -997,6 +1009,8 @@ static int tegra_dsi_exit(struct host1x_client *client)
                 }
         }
 
+        reset_control_assert(dsi->rst);
+
         return 0;
 }
 
@@ -1423,13 +1437,6 @@ static int tegra_dsi_probe(struct platform_device *pdev)
         if (IS_ERR(dsi->rst))
                 return PTR_ERR(dsi->rst);
 
-        err = reset_control_deassert(dsi->rst);
-        if (err < 0) {
-                dev_err(&pdev->dev, "failed to bring DSI out of reset: %d\n",
-                        err);
-                return err;
-        }
-
         dsi->clk = devm_clk_get(&pdev->dev, NULL);
         if (IS_ERR(dsi->clk)) {
                 dev_err(&pdev->dev, "cannot get DSI clock\n");
@@ -1495,12 +1502,6 @@ static int tegra_dsi_probe(struct platform_device *pdev)
                 goto disable_vdd;
         }
 
-        err = tegra_dsi_pad_calibrate(dsi);
-        if (err < 0) {
-                dev_err(dsi->dev, "MIPI calibration failed: %d\n", err);
-                goto mipi_free;
-        }
-
         dsi->host.ops = &tegra_dsi_host_ops;
         dsi->host.dev = &pdev->dev;