1 files changed, 85 insertions, 0 deletions
diff --git a/include/drm/display/drm_dp_aux_bus.h b/include/drm/display/drm_dp_aux_bus.h
new file mode 100644
index 000000000000..8a0a486383c5
--- /dev/null
+++ b/include/drm/display/drm_dp_aux_bus.h
@@ -0,0 +1,85 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Copyright 2021 Google Inc.
+ *
+ * The DP AUX bus is used for devices that are connected over a DisplayPort
+ * AUX bus. The devices on the far side of the bus are referred to as
+ * endpoints in this code.
+ */
+
+#ifndef _DP_AUX_BUS_H_
+#define _DP_AUX_BUS_H_
+
+#include <linux/device.h>
+#include <linux/mod_devicetable.h>
+
+/**
+ * struct dp_aux_ep_device - Main dev structure for DP AUX endpoints
+ *
+ * This is used to instantiate devices that are connected via a DP AUX
+ * bus. Usually the device is a panel, but conceivable other devices could
+ * be hooked up there.
+ */
+struct dp_aux_ep_device {
+	/** @dev: The normal dev pointer */
+	struct device dev;
+	/** @aux: Pointer to the aux bus */
+	struct drm_dp_aux *aux;
+};
+
+struct dp_aux_ep_driver {
+	int (*probe)(struct dp_aux_ep_device *aux_ep);
+	void (*remove)(struct dp_aux_ep_device *aux_ep);
+	void (*shutdown)(struct dp_aux_ep_device *aux_ep);
+	struct device_driver driver;
+};
+
+static inline struct dp_aux_ep_device *to_dp_aux_ep_dev(struct device *dev)
+{
+	return container_of(dev, struct dp_aux_ep_device, dev);
+}
+
+static inline struct dp_aux_ep_driver *to_dp_aux_ep_drv(struct device_driver *drv)
+{
+	return container_of(drv, struct dp_aux_ep_driver, driver);
+}
+
+int of_dp_aux_populate_bus(struct drm_dp_aux *aux,
+			   int (*done_probing)(struct drm_dp_aux *aux));
+void of_dp_aux_depopulate_bus(struct drm_dp_aux *aux);
+int devm_of_dp_aux_populate_bus(struct drm_dp_aux *aux,
+				int (*done_probing)(struct drm_dp_aux *aux));
+
+/* Deprecated versions of the above functions. To be removed when no callers. */
+static inline int of_dp_aux_populate_ep_devices(struct drm_dp_aux *aux)
+{
+	int ret;
+
+	ret = of_dp_aux_populate_bus(aux, NULL);
+
+	/* New API returns -ENODEV for no child case; adapt to old assumption */
+	return (ret != -ENODEV) ? ret : 0;
+}
+
+static inline int devm_of_dp_aux_populate_ep_devices(struct drm_dp_aux *aux)
+{
+	int ret;
+
+	ret = devm_of_dp_aux_populate_bus(aux, NULL);
+
+	/* New API returns -ENODEV for no child case; adapt to old assumption */
+	return (ret != -ENODEV) ? ret : 0;
+}
+
+static inline void of_dp_aux_depopulate_ep_devices(struct drm_dp_aux *aux)
+{
+	of_dp_aux_depopulate_bus(aux);
+}
+
+#define dp_aux_dp_driver_register(aux_ep_drv) \
+	__dp_aux_dp_driver_register(aux_ep_drv, THIS_MODULE)
+int __dp_aux_dp_driver_register(struct dp_aux_ep_driver *aux_ep_drv,
+				struct module *owner);
+void dp_aux_dp_driver_unregister(struct dp_aux_ep_driver *aux_ep_drv);
+
+#endif /* _DP_AUX_BUS_H_ */