1 files changed, 236 insertions, 0 deletions
diff --git a/drivers/media/cec/core/cec-notifier.c b/drivers/media/cec/core/cec-notifier.c
new file mode 100644
index 000000000000..517e0035fc99
--- /dev/null
+++ b/drivers/media/cec/core/cec-notifier.c
@@ -0,0 +1,236 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * cec-notifier.c - notify CEC drivers of physical address changes
+ *
+ * Copyright 2016 Russell King.
+ * Copyright 2016-2017 Cisco Systems, Inc. and/or its affiliates. All rights reserved.
+ */
+
+#include <linux/export.h>
+#include <linux/string.h>
+#include <linux/slab.h>
+#include <linux/list.h>
+#include <linux/kref.h>
+#include <linux/of_platform.h>
+
+#include <media/cec.h>
+#include <media/cec-notifier.h>
+#include <drm/drm_edid.h>
+
+struct cec_notifier {
+	struct mutex lock;
+	struct list_head head;
+	struct kref kref;
+	struct device *hdmi_dev;
+	struct cec_connector_info conn_info;
+	const char *port_name;
+	struct cec_adapter *cec_adap;
+
+	u16 phys_addr;
+};
+
+static LIST_HEAD(cec_notifiers);
+static DEFINE_MUTEX(cec_notifiers_lock);
+
+/**
+ * cec_notifier_get_conn - find or create a new cec_notifier for the given
+ * device and connector tuple.
+ * @hdmi_dev: device that sends the events.
+ * @port_name: the connector name from which the event occurs
+ *
+ * If a notifier for device @dev already exists, then increase the refcount
+ * and return that notifier.
+ *
+ * If it doesn't exist, then allocate a new notifier struct and return a
+ * pointer to that new struct.
+ *
+ * Return NULL if the memory could not be allocated.
+ */
+static struct cec_notifier *
+cec_notifier_get_conn(struct device *hdmi_dev, const char *port_name)
+{
+	struct cec_notifier *n;
+
+	mutex_lock(&cec_notifiers_lock);
+	list_for_each_entry(n, &cec_notifiers, head) {
+		if (n->hdmi_dev == hdmi_dev &&
+		    (!port_name ||
+		     (n->port_name && !strcmp(n->port_name, port_name)))) {
+			kref_get(&n->kref);
+			mutex_unlock(&cec_notifiers_lock);
+			return n;
+		}
+	}
+	n = kzalloc(sizeof(*n), GFP_KERNEL);
+	if (!n)
+		goto unlock;
+	n->hdmi_dev = hdmi_dev;
+	if (port_name) {
+		n->port_name = kstrdup(port_name, GFP_KERNEL);
+		if (!n->port_name) {
+			kfree(n);
+			n = NULL;
+			goto unlock;
+		}
+	}
+	n->phys_addr = CEC_PHYS_ADDR_INVALID;
+
+	mutex_init(&n->lock);
+	kref_init(&n->kref);
+	list_add_tail(&n->head, &cec_notifiers);
+unlock:
+	mutex_unlock(&cec_notifiers_lock);
+	return n;
+}
+
+static void cec_notifier_release(struct kref *kref)
+{
+	struct cec_notifier *n =
+		container_of(kref, struct cec_notifier, kref);
+
+	list_del(&n->head);
+	kfree(n->port_name);
+	kfree(n);
+}
+
+static void cec_notifier_put(struct cec_notifier *n)
+{
+	mutex_lock(&cec_notifiers_lock);
+	kref_put(&n->kref, cec_notifier_release);
+	mutex_unlock(&cec_notifiers_lock);
+}
+
+struct cec_notifier *
+cec_notifier_conn_register(struct device *hdmi_dev, const char *port_name,
+			   const struct cec_connector_info *conn_info)
+{
+	struct cec_notifier *n = cec_notifier_get_conn(hdmi_dev, port_name);
+
+	if (!n)
+		return n;
+
+	mutex_lock(&n->lock);
+	n->phys_addr = CEC_PHYS_ADDR_INVALID;
+	if (conn_info)
+		n->conn_info = *conn_info;
+	else
+		memset(&n->conn_info, 0, sizeof(n->conn_info));
+	if (n->cec_adap) {
+		cec_phys_addr_invalidate(n->cec_adap);
+		cec_s_conn_info(n->cec_adap, conn_info);
+	}
+	mutex_unlock(&n->lock);
+	return n;
+}
+EXPORT_SYMBOL_GPL(cec_notifier_conn_register);
+
+void cec_notifier_conn_unregister(struct cec_notifier *n)
+{
+	if (!n)
+		return;
+
+	mutex_lock(&n->lock);
+	memset(&n->conn_info, 0, sizeof(n->conn_info));
+	n->phys_addr = CEC_PHYS_ADDR_INVALID;
+	if (n->cec_adap) {
+		cec_phys_addr_invalidate(n->cec_adap);
+		cec_s_conn_info(n->cec_adap, NULL);
+	}
+	mutex_unlock(&n->lock);
+	cec_notifier_put(n);
+}
+EXPORT_SYMBOL_GPL(cec_notifier_conn_unregister);
+
+struct cec_notifier *
+cec_notifier_cec_adap_register(struct device *hdmi_dev, const char *port_name,
+			       struct cec_adapter *adap)
+{
+	struct cec_notifier *n;
+
+	if (WARN_ON(!adap))
+		return NULL;
+
+	n = cec_notifier_get_conn(hdmi_dev, port_name);
+	if (!n)
+		return n;
+
+	mutex_lock(&n->lock);
+	n->cec_adap = adap;
+	adap->conn_info = n->conn_info;
+	adap->notifier = n;
+	cec_s_phys_addr(adap, n->phys_addr, false);
+	mutex_unlock(&n->lock);
+	return n;
+}
+EXPORT_SYMBOL_GPL(cec_notifier_cec_adap_register);
+
+void cec_notifier_cec_adap_unregister(struct cec_notifier *n,
+				      struct cec_adapter *adap)
+{
+	if (!n)
+		return;
+
+	mutex_lock(&n->lock);
+	adap->notifier = NULL;
+	n->cec_adap = NULL;
+	mutex_unlock(&n->lock);
+	cec_notifier_put(n);
+}
+EXPORT_SYMBOL_GPL(cec_notifier_cec_adap_unregister);
+
+void cec_notifier_set_phys_addr(struct cec_notifier *n, u16 pa)
+{
+	if (n == NULL)
+		return;
+
+	mutex_lock(&n->lock);
+	n->phys_addr = pa;
+	if (n->cec_adap)
+		cec_s_phys_addr(n->cec_adap, n->phys_addr, false);
+	mutex_unlock(&n->lock);
+}
+EXPORT_SYMBOL_GPL(cec_notifier_set_phys_addr);
+
+void cec_notifier_set_phys_addr_from_edid(struct cec_notifier *n,
+					  const struct edid *edid)
+{
+	u16 pa = CEC_PHYS_ADDR_INVALID;
+
+	if (n == NULL)
+		return;
+
+	if (edid && edid->extensions)
+		pa = cec_get_edid_phys_addr((const u8 *)edid,
+				EDID_LENGTH * (edid->extensions + 1), NULL);
+	cec_notifier_set_phys_addr(n, pa);
+}
+EXPORT_SYMBOL_GPL(cec_notifier_set_phys_addr_from_edid);
+
+struct device *cec_notifier_parse_hdmi_phandle(struct device *dev)
+{
+	struct platform_device *hdmi_pdev;
+	struct device *hdmi_dev = NULL;
+	struct device_node *np;
+
+	np = of_parse_phandle(dev->of_node, "hdmi-phandle", 0);
+
+	if (!np) {
+		dev_err(dev, "Failed to find HDMI node in device tree\n");
+		return ERR_PTR(-ENODEV);
+	}
+	hdmi_pdev = of_find_device_by_node(np);
+	of_node_put(np);
+	if (hdmi_pdev) {
+		hdmi_dev = &hdmi_pdev->dev;
+		/*
+		 * Note that the device struct is only used as a key into the
+		 * cec_notifiers list, it is never actually accessed.
+		 * So we decrement the reference here so we don't leak
+		 * memory.
+		 */
+		put_device(hdmi_dev);
+		return hdmi_dev;
+	}
+	return ERR_PTR(-EPROBE_DEFER);
+}
+EXPORT_SYMBOL_GPL(cec_notifier_parse_hdmi_phandle);