1/* SPDX-License-Identifier: GPL-2.0-only */
  2/*
  3 * cec-notifier.h - notify CEC drivers of physical address changes
  4 *
  5 * Copyright 2016 Russell King.
  6 * Copyright 2016-2017 Cisco Systems, Inc. and/or its affiliates. All rights reserved.
  7 */
  8
  9#ifndef LINUX_CEC_NOTIFIER_H
 10#define LINUX_CEC_NOTIFIER_H
 11
 12#include <linux/err.h>
 13#include <media/cec.h>
 14
 15struct device;
 16struct edid;
 17struct cec_adapter;
 18struct cec_notifier;
 19
 20#if IS_REACHABLE(CONFIG_CEC_CORE) && IS_ENABLED(CONFIG_CEC_NOTIFIER)
 21
 22/**
 23 * cec_notifier_conn_register - find or create a new cec_notifier for the given
 24 * HDMI device and connector tuple.
 25 * @hdmi_dev: HDMI device that sends the events.
 26 * @port_name: the connector name from which the event occurs. May be NULL
 27 * if there is always only one HDMI connector created by the HDMI device.
 28 * @conn_info: the connector info from which the event occurs (may be NULL)
 29 *
 30 * If a notifier for device @dev and connector @port_name already exists, then
 31 * increase the refcount and return that notifier.
 32 *
 33 * If it doesn't exist, then allocate a new notifier struct and return a
 34 * pointer to that new struct.
 35 *
 36 * Return NULL if the memory could not be allocated.
 37 */
 38struct cec_notifier *
 39cec_notifier_conn_register(struct device *hdmi_dev, const char *port_name,
 40			   const struct cec_connector_info *conn_info);
 41
 42/**
 43 * cec_notifier_conn_unregister - decrease refcount and delete when the
 44 * refcount reaches 0.
 45 * @n: notifier. If NULL, then this function does nothing.
 46 */
 47void cec_notifier_conn_unregister(struct cec_notifier *n);
 48
 49/**
 50 * cec_notifier_cec_adap_register - find or create a new cec_notifier for the
 51 * given device.
 52 * @hdmi_dev: HDMI device that sends the events.
 53 * @port_name: the connector name from which the event occurs. May be NULL
 54 * if there is always only one HDMI connector created by the HDMI device.
 55 * @adap: the cec adapter that registered this notifier.
 56 *
 57 * If a notifier for device @dev and connector @port_name already exists, then
 58 * increase the refcount and return that notifier.
 59 *
 60 * If it doesn't exist, then allocate a new notifier struct and return a
 61 * pointer to that new struct.
 62 *
 63 * Return NULL if the memory could not be allocated.
 64 */
 65struct cec_notifier *
 66cec_notifier_cec_adap_register(struct device *hdmi_dev, const char *port_name,
 67			       struct cec_adapter *adap);
 68
 69/**
 70 * cec_notifier_cec_adap_unregister - decrease refcount and delete when the
 71 * refcount reaches 0.
 72 * @n: notifier. If NULL, then this function does nothing.
 73 * @adap: the cec adapter that registered this notifier.
 74 */
 75void cec_notifier_cec_adap_unregister(struct cec_notifier *n,
 76				      struct cec_adapter *adap);
 77
 78/**
 79 * cec_notifier_set_phys_addr - set a new physical address.
 80 * @n: the CEC notifier
 81 * @pa: the CEC physical address
 82 *
 83 * Set a new CEC physical address.
 84 * Does nothing if @n == NULL.
 85 */
 86void cec_notifier_set_phys_addr(struct cec_notifier *n, u16 pa);
 87
 88/**
 89 * cec_notifier_set_phys_addr_from_edid - set parse the PA from the EDID.
 90 * @n: the CEC notifier
 91 * @edid: the struct edid pointer
 92 *
 93 * Parses the EDID to obtain the new CEC physical address and set it.
 94 * Does nothing if @n == NULL.
 95 */
 96void cec_notifier_set_phys_addr_from_edid(struct cec_notifier *n,
 97					  const struct edid *edid);
 98
 99/**
100 * cec_notifier_parse_hdmi_phandle - find the hdmi device from "hdmi-phandle"
101 * @dev: the device with the "hdmi-phandle" device tree property
102 *
103 * Returns the device pointer referenced by the "hdmi-phandle" property.
104 * Note that the refcount of the returned device is not incremented.
105 * This device pointer is only used as a key value in the notifier
106 * list, but it is never accessed by the CEC driver.
107 */
108struct device *cec_notifier_parse_hdmi_phandle(struct device *dev);
109
110#else
111
112static inline struct cec_notifier *
113cec_notifier_conn_register(struct device *hdmi_dev, const char *port_name,
114			   const struct cec_connector_info *conn_info)
115{
116	/* A non-NULL pointer is expected on success */
117	return (struct cec_notifier *)0xdeadfeed;
118}
119
120static inline void cec_notifier_conn_unregister(struct cec_notifier *n)
121{
122}
123
124static inline struct cec_notifier *
125cec_notifier_cec_adap_register(struct device *hdmi_dev, const char *port_name,
126			       struct cec_adapter *adap)
127{
128	/* A non-NULL pointer is expected on success */
129	return (struct cec_notifier *)0xdeadfeed;
130}
131
132static inline void cec_notifier_cec_adap_unregister(struct cec_notifier *n,
133						    struct cec_adapter *adap)
134{
135}
136
137static inline void cec_notifier_set_phys_addr(struct cec_notifier *n, u16 pa)
138{
139}
140
141static inline void cec_notifier_set_phys_addr_from_edid(struct cec_notifier *n,
142							const struct edid *edid)
143{
144}
145
146static inline struct device *cec_notifier_parse_hdmi_phandle(struct device *dev)
147{
148	return ERR_PTR(-ENODEV);
149}
150
151#endif
152
153/**
154 * cec_notifier_phys_addr_invalidate() - set the physical address to INVALID
155 *
156 * @n: the CEC notifier
157 *
158 * This is a simple helper function to invalidate the physical
159 * address. Does nothing if @n == NULL.
160 */
161static inline void cec_notifier_phys_addr_invalidate(struct cec_notifier *n)
162{
163	cec_notifier_set_phys_addr(n, CEC_PHYS_ADDR_INVALID);
164}
165
166#endif