drm/vc4: dpi: Add action to disable the clock

The DPI controller has two clocks called core and pixel, the core clock
being enabled at bind time.

Adding a device-managed action will make the error path easier, so let's
create one to disable it.
Acked-by: Thomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: Dave Stevenson <dave.stevenson@raspberrypi.com>
Signed-off-by: Maxime Ripard <maxime@cerno.tech>
Link: https://lore.kernel.org/r/20220711173939.1132294-29-maxime@cerno.tech

drivers/gpu/drm/vc4/vc4_dpi.c

@@ -257,6 +257,13 @@ static int vc4_dpi_init_bridge(struct vc4_dpi *dpi)
 	return drm_bridge_attach(&dpi->encoder.base, bridge, NULL, 0);
 }
 
+static void vc4_dpi_disable_clock(void *ptr)
+{
+	struct vc4_dpi *dpi = ptr;
+
+	clk_disable_unprepare(dpi->core_clock);
+}
+
 static int vc4_dpi_bind(struct device *dev, struct device *master, void *data)
 {
 	struct platform_device *pdev = to_platform_device(dev);
@@ -305,6 +312,10 @@ static int vc4_dpi_bind(struct device *dev, struct device *master, void *data)
 		return ret;
 	}
 
+	ret = devm_add_action_or_reset(dev, vc4_dpi_disable_clock, dpi);
+	if (ret)
+		return ret;
+
 	drm_simple_encoder_init(drm, &dpi->encoder.base, DRM_MODE_ENCODER_DPI);
 	drm_encoder_helper_add(&dpi->encoder.base, &vc4_dpi_encoder_helper_funcs);
 
@@ -320,7 +331,6 @@ static int vc4_dpi_bind(struct device *dev, struct device *master, void *data)
 
 err_destroy_encoder:
 	drm_encoder_cleanup(&dpi->encoder.base);
-	clk_disable_unprepare(dpi->core_clock);
 	return ret;
 }
 
@@ -330,8 +340,6 @@ static void vc4_dpi_unbind(struct device *dev, struct device *master,
 	struct vc4_dpi *dpi = dev_get_drvdata(dev);
 
 	drm_encoder_cleanup(&dpi->encoder.base);
-
-	clk_disable_unprepare(dpi->core_clock);
 }
 
 static const struct component_ops vc4_dpi_ops = {