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1// SPDX-License-Identifier: GPL-2.0-only2/*3 * cec-notifier.c - notify CEC drivers of physical address changes4 *5 * Copyright 2016 Russell King.6 * Copyright 2016-2017 Cisco Systems, Inc. and/or its affiliates. All rights reserved.7 */8 9#include <linux/export.h>10#include <linux/platform_device.h>11#include <linux/string.h>12#include <linux/slab.h>13#include <linux/i2c.h>14#include <linux/list.h>15#include <linux/kref.h>16#include <linux/of_platform.h>17 18#include <media/cec.h>19#include <media/cec-notifier.h>20#include <drm/drm_edid.h>21 22struct cec_notifier {23 struct mutex lock;24 struct list_head head;25 struct kref kref;26 struct device *hdmi_dev;27 struct cec_connector_info conn_info;28 const char *port_name;29 struct cec_adapter *cec_adap;30 31 u16 phys_addr;32};33 34static LIST_HEAD(cec_notifiers);35static DEFINE_MUTEX(cec_notifiers_lock);36 37/**38 * cec_notifier_get_conn - find or create a new cec_notifier for the given39 * device and connector tuple.40 * @hdmi_dev: device that sends the events.41 * @port_name: the connector name from which the event occurs42 *43 * If a notifier for device @dev already exists, then increase the refcount44 * and return that notifier.45 *46 * If it doesn't exist, then allocate a new notifier struct and return a47 * pointer to that new struct.48 *49 * Return NULL if the memory could not be allocated.50 */51static struct cec_notifier *52cec_notifier_get_conn(struct device *hdmi_dev, const char *port_name)53{54 struct cec_notifier *n;55 56 mutex_lock(&cec_notifiers_lock);57 list_for_each_entry(n, &cec_notifiers, head) {58 if (n->hdmi_dev == hdmi_dev &&59 (!port_name ||60 (n->port_name && !strcmp(n->port_name, port_name)))) {61 kref_get(&n->kref);62 mutex_unlock(&cec_notifiers_lock);63 return n;64 }65 }66 n = kzalloc(sizeof(*n), GFP_KERNEL);67 if (!n)68 goto unlock;69 n->hdmi_dev = hdmi_dev;70 if (port_name) {71 n->port_name = kstrdup(port_name, GFP_KERNEL);72 if (!n->port_name) {73 kfree(n);74 n = NULL;75 goto unlock;76 }77 }78 n->phys_addr = CEC_PHYS_ADDR_INVALID;79 80 mutex_init(&n->lock);81 kref_init(&n->kref);82 list_add_tail(&n->head, &cec_notifiers);83unlock:84 mutex_unlock(&cec_notifiers_lock);85 return n;86}87 88static void cec_notifier_release(struct kref *kref)89{90 struct cec_notifier *n =91 container_of(kref, struct cec_notifier, kref);92 93 list_del(&n->head);94 kfree(n->port_name);95 kfree(n);96}97 98static void cec_notifier_put(struct cec_notifier *n)99{100 mutex_lock(&cec_notifiers_lock);101 kref_put(&n->kref, cec_notifier_release);102 mutex_unlock(&cec_notifiers_lock);103}104 105struct cec_notifier *106cec_notifier_conn_register(struct device *hdmi_dev, const char *port_name,107 const struct cec_connector_info *conn_info)108{109 struct cec_notifier *n = cec_notifier_get_conn(hdmi_dev, port_name);110 111 if (!n)112 return n;113 114 mutex_lock(&n->lock);115 n->phys_addr = CEC_PHYS_ADDR_INVALID;116 if (conn_info)117 n->conn_info = *conn_info;118 else119 memset(&n->conn_info, 0, sizeof(n->conn_info));120 if (n->cec_adap) {121 if (!n->cec_adap->adap_controls_phys_addr)122 cec_phys_addr_invalidate(n->cec_adap);123 cec_s_conn_info(n->cec_adap, conn_info);124 }125 mutex_unlock(&n->lock);126 return n;127}128EXPORT_SYMBOL_GPL(cec_notifier_conn_register);129 130void cec_notifier_conn_unregister(struct cec_notifier *n)131{132 if (!n)133 return;134 135 mutex_lock(&n->lock);136 memset(&n->conn_info, 0, sizeof(n->conn_info));137 n->phys_addr = CEC_PHYS_ADDR_INVALID;138 if (n->cec_adap) {139 if (!n->cec_adap->adap_controls_phys_addr)140 cec_phys_addr_invalidate(n->cec_adap);141 cec_s_conn_info(n->cec_adap, NULL);142 }143 mutex_unlock(&n->lock);144 cec_notifier_put(n);145}146EXPORT_SYMBOL_GPL(cec_notifier_conn_unregister);147 148struct cec_notifier *149cec_notifier_cec_adap_register(struct device *hdmi_dev, const char *port_name,150 struct cec_adapter *adap)151{152 struct cec_notifier *n;153 154 if (WARN_ON(!adap))155 return NULL;156 157 n = cec_notifier_get_conn(hdmi_dev, port_name);158 if (!n)159 return n;160 161 mutex_lock(&n->lock);162 n->cec_adap = adap;163 adap->conn_info = n->conn_info;164 adap->notifier = n;165 if (!adap->adap_controls_phys_addr)166 cec_s_phys_addr(adap, n->phys_addr, false);167 mutex_unlock(&n->lock);168 return n;169}170EXPORT_SYMBOL_GPL(cec_notifier_cec_adap_register);171 172void cec_notifier_cec_adap_unregister(struct cec_notifier *n,173 struct cec_adapter *adap)174{175 if (!n)176 return;177 178 mutex_lock(&n->lock);179 adap->notifier = NULL;180 n->cec_adap = NULL;181 mutex_unlock(&n->lock);182 cec_notifier_put(n);183}184EXPORT_SYMBOL_GPL(cec_notifier_cec_adap_unregister);185 186void cec_notifier_set_phys_addr(struct cec_notifier *n, u16 pa)187{188 if (n == NULL)189 return;190 191 mutex_lock(&n->lock);192 n->phys_addr = pa;193 if (n->cec_adap && !n->cec_adap->adap_controls_phys_addr)194 cec_s_phys_addr(n->cec_adap, n->phys_addr, false);195 mutex_unlock(&n->lock);196}197EXPORT_SYMBOL_GPL(cec_notifier_set_phys_addr);198 199/*200 * Note: In the drm subsystem, prefer calling (if possible):201 *202 * cec_notifier_set_phys_addr(n, connector->display_info.source_physical_address);203 */204void cec_notifier_set_phys_addr_from_edid(struct cec_notifier *n,205 const struct edid *edid)206{207 u16 pa = CEC_PHYS_ADDR_INVALID;208 209 if (n == NULL)210 return;211 212 if (edid && edid->extensions)213 pa = cec_get_edid_phys_addr((const u8 *)edid,214 EDID_LENGTH * (edid->extensions + 1), NULL);215 cec_notifier_set_phys_addr(n, pa);216}217EXPORT_SYMBOL_GPL(cec_notifier_set_phys_addr_from_edid);218 219struct device *cec_notifier_parse_hdmi_phandle(struct device *dev)220{221 struct platform_device *hdmi_pdev;222 struct device *hdmi_dev = NULL;223 struct device_node *np;224 225 np = of_parse_phandle(dev->of_node, "hdmi-phandle", 0);226 227 if (!np) {228 dev_err(dev, "Failed to find HDMI node in device tree\n");229 return ERR_PTR(-ENODEV);230 }231 232 hdmi_pdev = of_find_device_by_node(np);233 if (hdmi_pdev)234 hdmi_dev = &hdmi_pdev->dev;235#if IS_REACHABLE(CONFIG_I2C)236 if (!hdmi_dev) {237 struct i2c_client *hdmi_client = of_find_i2c_device_by_node(np);238 239 if (hdmi_client)240 hdmi_dev = &hdmi_client->dev;241 }242#endif243 of_node_put(np);244 if (!hdmi_dev)245 return ERR_PTR(-EPROBE_DEFER);246 247 /*248 * Note that the device struct is only used as a key into the249 * cec_notifiers list, it is never actually accessed.250 * So we decrement the reference here so we don't leak251 * memory.252 */253 put_device(hdmi_dev);254 return hdmi_dev;255}256EXPORT_SYMBOL_GPL(cec_notifier_parse_hdmi_phandle);257