125 lines
2.8 KiB
C
125 lines
2.8 KiB
C
// SPDX-License-Identifier: GPL-2.0-only
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/*
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* cec-notifier.c - notify CEC drivers of physical address changes
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*
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* Copyright 2016 Russell King <rmk+kernel@arm.linux.org.uk>
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* Copyright 2016-2017 Cisco Systems, Inc. and/or its affiliates. All rights reserved.
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*/
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#include <linux/export.h>
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#include <linux/string.h>
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#include <linux/slab.h>
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#include <linux/list.h>
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#include <linux/kref.h>
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#include <media/cec.h>
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#include <media/cec-notifier.h>
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#include <drm/drm_edid.h>
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struct cec_notifier {
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struct mutex lock;
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struct list_head head;
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struct kref kref;
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struct device *dev;
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struct cec_adapter *cec_adap;
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void (*callback)(struct cec_adapter *adap, u16 pa);
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u16 phys_addr;
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};
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static LIST_HEAD(cec_notifiers);
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static DEFINE_MUTEX(cec_notifiers_lock);
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struct cec_notifier *cec_notifier_get(struct device *dev)
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{
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struct cec_notifier *n;
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mutex_lock(&cec_notifiers_lock);
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list_for_each_entry(n, &cec_notifiers, head) {
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if (n->dev == dev) {
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kref_get(&n->kref);
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mutex_unlock(&cec_notifiers_lock);
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return n;
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}
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}
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n = kzalloc(sizeof(*n), GFP_KERNEL);
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if (!n)
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goto unlock;
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n->dev = dev;
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n->phys_addr = CEC_PHYS_ADDR_INVALID;
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mutex_init(&n->lock);
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kref_init(&n->kref);
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list_add_tail(&n->head, &cec_notifiers);
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unlock:
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mutex_unlock(&cec_notifiers_lock);
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return n;
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}
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EXPORT_SYMBOL_GPL(cec_notifier_get);
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static void cec_notifier_release(struct kref *kref)
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{
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struct cec_notifier *n =
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container_of(kref, struct cec_notifier, kref);
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list_del(&n->head);
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kfree(n);
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}
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void cec_notifier_put(struct cec_notifier *n)
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{
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mutex_lock(&cec_notifiers_lock);
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kref_put(&n->kref, cec_notifier_release);
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mutex_unlock(&cec_notifiers_lock);
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}
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EXPORT_SYMBOL_GPL(cec_notifier_put);
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void cec_notifier_set_phys_addr(struct cec_notifier *n, u16 pa)
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{
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if (n == NULL)
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return;
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mutex_lock(&n->lock);
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n->phys_addr = pa;
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if (n->callback)
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n->callback(n->cec_adap, n->phys_addr);
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mutex_unlock(&n->lock);
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}
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EXPORT_SYMBOL_GPL(cec_notifier_set_phys_addr);
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void cec_notifier_set_phys_addr_from_edid(struct cec_notifier *n,
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const struct edid *edid)
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{
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u16 pa = CEC_PHYS_ADDR_INVALID;
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if (n == NULL)
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return;
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if (edid && edid->extensions)
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pa = cec_get_edid_phys_addr((const u8 *)edid,
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EDID_LENGTH * (edid->extensions + 1), NULL);
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cec_notifier_set_phys_addr(n, pa);
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}
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EXPORT_SYMBOL_GPL(cec_notifier_set_phys_addr_from_edid);
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void cec_notifier_register(struct cec_notifier *n,
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struct cec_adapter *adap,
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void (*callback)(struct cec_adapter *adap, u16 pa))
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{
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kref_get(&n->kref);
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mutex_lock(&n->lock);
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n->cec_adap = adap;
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n->callback = callback;
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n->callback(adap, n->phys_addr);
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mutex_unlock(&n->lock);
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}
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EXPORT_SYMBOL_GPL(cec_notifier_register);
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void cec_notifier_unregister(struct cec_notifier *n)
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{
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mutex_lock(&n->lock);
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n->callback = NULL;
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mutex_unlock(&n->lock);
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cec_notifier_put(n);
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}
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EXPORT_SYMBOL_GPL(cec_notifier_unregister);
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