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	In non device-tree world, we can need to get the notifier by the driver name directly and eventually defer probe if not yet created. This patch adds a variant of the get function by using the device name instead and will not create a notifier if not yet created. But the i915 driver exposes at least 2 HDMI connectors, this patch also adds the possibility to add a connector name tied to the notifier device to form a tuple and associate different CEC controllers for each HDMI connectors. Signed-off-by: Neil Armstrong <narmstrong@baylibre.com> Reviewed-by: Hans Verkuil <hans.verkuil@cisco.com> Signed-off-by: Lee Jones <lee.jones@linaro.org>
		
			
				
	
	
		
			129 lines
		
	
	
	
		
			3 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			129 lines
		
	
	
	
		
			3 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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	const char *conn;
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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_conn(struct device *dev, const char *conn)
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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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		    (!conn || !strcmp(n->conn, conn))) {
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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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	if (conn)
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		n->conn = kstrdup(conn, GFP_KERNEL);
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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_conn);
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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->conn);
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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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