Let's provide an helper to make it easier for bridge drivers to
power-cycle their bridge.
In order to avoid a circular dependency between that new helper and
drm_atomic_helper_reset_crtc(), this new helper will be in a
drm_bridge_helper.c file to follow the pattern we have for other
objects.
Co-developed-by: Simona Vetter <simona.vetter@xxxxxxxx>
Signed-off-by: Maxime Ripard <mripard@xxxxxxxxxx>
---
drivers/gpu/drm/Makefile | 1 +
drivers/gpu/drm/drm_bridge_helper.c | 55 +++++++++++++++++++++++++++++++++++++
include/drm/drm_bridge_helper.h | 12 ++++++++
3 files changed, 68 insertions(+)
diff --git a/drivers/gpu/drm/Makefile b/drivers/gpu/drm/Makefile
index 4cd054188faf0b3dec442efd99ae52604541bce1..5a332f7d3ecccb6e5e1fb9fb811eab7aa5a84a21 100644
--- a/drivers/gpu/drm/Makefile
+++ b/drivers/gpu/drm/Makefile
@@ -131,10 +131,11 @@ obj-$(CONFIG_DRM_TTM_HELPER) += drm_ttm_helper.o
#
drm_kms_helper-y := \
drm_atomic_helper.o \
drm_atomic_state_helper.o \
+ drm_bridge_helper.o \
drm_crtc_helper.o \
drm_damage_helper.o \
drm_flip_work.o \
drm_format_helper.o \
drm_gem_atomic_helper.o \
diff --git a/drivers/gpu/drm/drm_bridge_helper.c b/drivers/gpu/drm/drm_bridge_helper.c
new file mode 100644
index 0000000000000000000000000000000000000000..521df9d5dcb3fef842a95cdb2865a8b8d09b0fbe
--- /dev/null
+++ b/drivers/gpu/drm/drm_bridge_helper.c
@@ -0,0 +1,55 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+
+#include <drm/drm_atomic.h>
+#include <drm/drm_atomic_helper.h>
+#include <drm/drm_bridge.h>
+#include <drm/drm_bridge_helper.h>
+#include <drm/drm_modeset_lock.h>
+
+/**
+ * drm_bridge_helper_reset_crtc - Reset the pipeline feeding a bridge
+ * @bridge: DRM bridge to reset
+ * @ctx: lock acquisition context
+ *
+ * Reset a @bridge pipeline. It will power-cycle all active components
+ * between the CRTC and connector that bridge is connected to.
+ *
+ * Returns:
+ *
+ * 0 on success or a negative error code on failure. If the error
+ * returned is EDEADLK, the whole atomic sequence must be restarted.
+ */
+int drm_bridge_helper_reset_crtc(struct drm_bridge *bridge,
+ struct drm_modeset_acquire_ctx *ctx)
+{
+ struct drm_connector *connector;
+ struct drm_encoder *encoder = bridge->encoder;
+ struct drm_device *dev = encoder->dev;
+ struct drm_crtc *crtc;
+ int ret;
+
+ ret = drm_modeset_lock(&dev->mode_config.connection_mutex, ctx);
+ if (ret)
+ return ret;
+
+ connector = drm_atomic_get_connector_for_encoder(encoder, ctx);
+ if (IS_ERR(connector)) {
+ ret = PTR_ERR(connector);
+ goto out;
+ }
+
+ if (!connector->state) {
+ ret = -EINVAL;
+ goto out;
+ }
+
+ crtc = connector->state->crtc;
+ ret = drm_atomic_helper_reset_crtc(crtc, ctx);
+ if (ret)
+ goto out;
+
+out:
+ drm_modeset_unlock(&dev->mode_config.connection_mutex);
+ return ret;
+}
+EXPORT_SYMBOL(drm_bridge_helper_reset_crtc);
diff --git a/include/drm/drm_bridge_helper.h b/include/drm/drm_bridge_helper.h
new file mode 100644
index 0000000000000000000000000000000000000000..6c35b479ec2a84aa43283351a6f18e49a9f9c177
--- /dev/null
+++ b/include/drm/drm_bridge_helper.h
@@ -0,0 +1,12 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+
+#ifndef __DRM_BRIDGE_HELPER_H_
+#define __DRM_BRIDGE_HELPER_H_
+
+struct drm_bridge;
+struct drm_modeset_acquire_ctx;
+
+int drm_bridge_helper_reset_crtc(struct drm_bridge *bridge,
+ struct drm_modeset_acquire_ctx *ctx);
+
+#endif // __DRM_BRIDGE_HELPER_H_
--
2.48.1
