linux/drivers/media/cec/cec-notifier.c

224 lines
5.1 KiB
C

// SPDX-License-Identifier: GPL-2.0-only
/*
* cec-notifier.c - notify CEC drivers of physical address changes
*
* Copyright 2016 Russell King <rmk+kernel@arm.linux.org.uk>
* 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 *conn_name;
struct cec_adapter *cec_adap;
u16 phys_addr;
};
static LIST_HEAD(cec_notifiers);
static DEFINE_MUTEX(cec_notifiers_lock);
struct cec_notifier *
cec_notifier_get_conn(struct device *hdmi_dev, const char *conn_name)
{
struct cec_notifier *n;
mutex_lock(&cec_notifiers_lock);
list_for_each_entry(n, &cec_notifiers, head) {
if (n->hdmi_dev == hdmi_dev &&
(!conn_name ||
(n->conn_name && !strcmp(n->conn_name, conn_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 (conn_name) {
n->conn_name = kstrdup(conn_name, GFP_KERNEL);
if (!n->conn_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;
}
EXPORT_SYMBOL_GPL(cec_notifier_get_conn);
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->conn_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 *conn_name,
const struct cec_connector_info *conn_info)
{
struct cec_notifier *n = cec_notifier_get_conn(hdmi_dev, conn_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 *conn_name,
struct cec_adapter *adap)
{
struct cec_notifier *n;
if (WARN_ON(!adap))
return NULL;
n = cec_notifier_get_conn(hdmi_dev, conn_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);