--- /dev/null
+/*
+ * cec-core.c - HDMI Consumer Electronics Control framework - Core
+ *
+ * Copyright 2016 Cisco Systems, Inc. and/or its affiliates. All rights reserved.
+ *
+ * This program is free software; you may redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; version 2 of the License.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+ * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+ * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
+ * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
+ * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
+ * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+#include <linux/errno.h>
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/kmod.h>
+#include <linux/slab.h>
+#include <linux/mm.h>
+#include <linux/string.h>
+#include <linux/types.h>
+
+#include "cec-priv.h"
+
+#define CEC_NUM_DEVICES 256
+#define CEC_NAME "cec"
+
+int cec_debug;
+module_param_named(debug, cec_debug, int, 0644);
+MODULE_PARM_DESC(debug, "debug level (0-2)");
+
+static dev_t cec_dev_t;
+
+/* Active devices */
+static DEFINE_MUTEX(cec_devnode_lock);
+static DECLARE_BITMAP(cec_devnode_nums, CEC_NUM_DEVICES);
+
+static struct dentry *top_cec_dir;
+
+/* dev to cec_devnode */
+#define to_cec_devnode(cd) container_of(cd, struct cec_devnode, dev)
+
+int cec_get_device(struct cec_devnode *devnode)
+{
+ /*
+ * Check if the cec device is available. This needs to be done with
+ * the cec_devnode_lock held to prevent an open/unregister race:
+ * without the lock, the device could be unregistered and freed between
+ * the devnode->registered check and get_device() calls, leading to
+ * a crash.
+ */
+ mutex_lock(&cec_devnode_lock);
+ /*
+ * return ENXIO if the cec device has been removed
+ * already or if it is not registered anymore.
+ */
+ if (!devnode->registered) {
+ mutex_unlock(&cec_devnode_lock);
+ return -ENXIO;
+ }
+ /* and increase the device refcount */
+ get_device(&devnode->dev);
+ mutex_unlock(&cec_devnode_lock);
+ return 0;
+}
+
+void cec_put_device(struct cec_devnode *devnode)
+{
+ mutex_lock(&cec_devnode_lock);
+ put_device(&devnode->dev);
+ mutex_unlock(&cec_devnode_lock);
+}
+
+/* Called when the last user of the cec device exits. */
+static void cec_devnode_release(struct device *cd)
+{
+ struct cec_devnode *devnode = to_cec_devnode(cd);
+
+ mutex_lock(&cec_devnode_lock);
+
+ /* Mark device node number as free */
+ clear_bit(devnode->minor, cec_devnode_nums);
+
+ mutex_unlock(&cec_devnode_lock);
+ cec_delete_adapter(to_cec_adapter(devnode));
+}
+
+static struct bus_type cec_bus_type = {
+ .name = CEC_NAME,
+};
+
+/*
+ * Register a cec device node
+ *
+ * The registration code assigns minor numbers and registers the new device node
+ * with the kernel. An error is returned if no free minor number can be found,
+ * or if the registration of the device node fails.
+ *
+ * Zero is returned on success.
+ *
+ * Note that if the cec_devnode_register call fails, the release() callback of
+ * the cec_devnode structure is *not* called, so the caller is responsible for
+ * freeing any data.
+ */
+static int __must_check cec_devnode_register(struct cec_devnode *devnode,
+ struct module *owner)
+{
+ int minor;
+ int ret;
+
+ /* Initialization */
+ INIT_LIST_HEAD(&devnode->fhs);
+ mutex_init(&devnode->fhs_lock);
+
+ /* Part 1: Find a free minor number */
+ mutex_lock(&cec_devnode_lock);
+ minor = find_next_zero_bit(cec_devnode_nums, CEC_NUM_DEVICES, 0);
+ if (minor == CEC_NUM_DEVICES) {
+ mutex_unlock(&cec_devnode_lock);
+ pr_err("could not get a free minor\n");
+ return -ENFILE;
+ }
+
+ set_bit(minor, cec_devnode_nums);
+ mutex_unlock(&cec_devnode_lock);
+
+ devnode->minor = minor;
+ devnode->dev.bus = &cec_bus_type;
+ devnode->dev.devt = MKDEV(MAJOR(cec_dev_t), minor);
+ devnode->dev.release = cec_devnode_release;
+ devnode->dev.parent = devnode->parent;
+ dev_set_name(&devnode->dev, "cec%d", devnode->minor);
+ device_initialize(&devnode->dev);
+
+ /* Part 2: Initialize and register the character device */
+ cdev_init(&devnode->cdev, &cec_devnode_fops);
+ devnode->cdev.kobj.parent = &devnode->dev.kobj;
+ devnode->cdev.owner = owner;
+
+ ret = cdev_add(&devnode->cdev, devnode->dev.devt, 1);
+ if (ret < 0) {
+ pr_err("%s: cdev_add failed\n", __func__);
+ goto clr_bit;
+ }
+
+ ret = device_add(&devnode->dev);
+ if (ret)
+ goto cdev_del;
+
+ devnode->registered = true;
+ return 0;
+
+cdev_del:
+ cdev_del(&devnode->cdev);
+clr_bit:
+ clear_bit(devnode->minor, cec_devnode_nums);
+ return ret;
+}
+
+/*
+ * Unregister a cec device node
+ *
+ * This unregisters the passed device. Future open calls will be met with
+ * errors.
+ *
+ * This function can safely be called if the device node has never been
+ * registered or has already been unregistered.
+ */
+static void cec_devnode_unregister(struct cec_devnode *devnode)
+{
+ struct cec_fh *fh;
+
+ /* Check if devnode was never registered or already unregistered */
+ if (!devnode->registered || devnode->unregistered)
+ return;
+
+ mutex_lock(&devnode->fhs_lock);
+ list_for_each_entry(fh, &devnode->fhs, list)
+ wake_up_interruptible(&fh->wait);
+ mutex_unlock(&devnode->fhs_lock);
+
+ devnode->registered = false;
+ devnode->unregistered = true;
+ device_del(&devnode->dev);
+ cdev_del(&devnode->cdev);
+ put_device(&devnode->dev);
+}
+
+struct cec_adapter *cec_allocate_adapter(const struct cec_adap_ops *ops,
+ void *priv, const char *name, u32 caps,
+ u8 available_las, struct device *parent)
+{
+ struct cec_adapter *adap;
+ int res;
+
+ if (WARN_ON(!parent))
+ return ERR_PTR(-EINVAL);
+ if (WARN_ON(!caps))
+ return ERR_PTR(-EINVAL);
+ if (WARN_ON(!ops))
+ return ERR_PTR(-EINVAL);
+ if (WARN_ON(!available_las || available_las > CEC_MAX_LOG_ADDRS))
+ return ERR_PTR(-EINVAL);
+ adap = kzalloc(sizeof(*adap), GFP_KERNEL);
+ if (!adap)
+ return ERR_PTR(-ENOMEM);
+ adap->owner = parent->driver->owner;
+ adap->devnode.parent = parent;
+ strlcpy(adap->name, name, sizeof(adap->name));
+ adap->phys_addr = CEC_PHYS_ADDR_INVALID;
+ adap->log_addrs.cec_version = CEC_OP_CEC_VERSION_2_0;
+ adap->log_addrs.vendor_id = CEC_VENDOR_ID_NONE;
+ adap->capabilities = caps;
+ adap->available_log_addrs = available_las;
+ adap->sequence = 0;
+ adap->ops = ops;
+ adap->priv = priv;
+ memset(adap->phys_addrs, 0xff, sizeof(adap->phys_addrs));
+ mutex_init(&adap->lock);
+ INIT_LIST_HEAD(&adap->transmit_queue);
+ INIT_LIST_HEAD(&adap->wait_queue);
+ init_waitqueue_head(&adap->kthread_waitq);
+
+ adap->kthread = kthread_run(cec_thread_func, adap, "cec-%s", name);
+ if (IS_ERR(adap->kthread)) {
+ pr_err("cec-%s: kernel_thread() failed\n", name);
+ res = PTR_ERR(adap->kthread);
+ kfree(adap);
+ return ERR_PTR(res);
+ }
+
+ if (!(caps & CEC_CAP_RC))
+ return adap;
+
+#if IS_ENABLED(CONFIG_RC_CORE)
+ /* Prepare the RC input device */
+ adap->rc = rc_allocate_device();
+ if (!adap->rc) {
+ pr_err("cec-%s: failed to allocate memory for rc_dev\n",
+ name);
+ kthread_stop(adap->kthread);
+ kfree(adap);
+ return ERR_PTR(-ENOMEM);
+ }
+
+ snprintf(adap->input_name, sizeof(adap->input_name),
+ "RC for %s", name);
+ snprintf(adap->input_phys, sizeof(adap->input_phys),
+ "%s/input0", name);
+
+ adap->rc->input_name = adap->input_name;
+ adap->rc->input_phys = adap->input_phys;
+ adap->rc->input_id.bustype = BUS_CEC;
+ adap->rc->input_id.vendor = 0;
+ adap->rc->input_id.product = 0;
+ adap->rc->input_id.version = 1;
+ adap->rc->dev.parent = parent;
+ adap->rc->driver_type = RC_DRIVER_SCANCODE;
+ adap->rc->driver_name = CEC_NAME;
+ adap->rc->allowed_protocols = RC_BIT_CEC;
+ adap->rc->priv = adap;
+ adap->rc->map_name = RC_MAP_CEC;
+ adap->rc->timeout = MS_TO_NS(100);
+#else
+ adap->capabilities &= ~CEC_CAP_RC;
+#endif
+ return adap;
+}
+EXPORT_SYMBOL_GPL(cec_allocate_adapter);
+
+int cec_register_adapter(struct cec_adapter *adap)
+{
+ int res;
+
+ if (IS_ERR_OR_NULL(adap))
+ return 0;
+
+#if IS_ENABLED(CONFIG_RC_CORE)
+ if (adap->capabilities & CEC_CAP_RC) {
+ res = rc_register_device(adap->rc);
+
+ if (res) {
+ pr_err("cec-%s: failed to prepare input device\n",
+ adap->name);
+ rc_free_device(adap->rc);
+ adap->rc = NULL;
+ return res;
+ }
+ }
+#endif
+
+ res = cec_devnode_register(&adap->devnode, adap->owner);
+ if (res) {
+#if IS_ENABLED(CONFIG_RC_CORE)
+ /* Note: rc_unregister also calls rc_free */
+ rc_unregister_device(adap->rc);
+ adap->rc = NULL;
+#endif
+ return res;
+ }
+
+ dev_set_drvdata(&adap->devnode.dev, adap);
+#ifdef CONFIG_MEDIA_CEC_DEBUG
+ if (!top_cec_dir)
+ return 0;
+
+ adap->cec_dir = debugfs_create_dir(dev_name(&adap->devnode.dev), top_cec_dir);
+ if (IS_ERR_OR_NULL(adap->cec_dir)) {
+ pr_warn("cec-%s: Failed to create debugfs dir\n", adap->name);
+ return 0;
+ }
+ adap->status_file = debugfs_create_devm_seqfile(&adap->devnode.dev,
+ "status", adap->cec_dir, cec_adap_status);
+ if (IS_ERR_OR_NULL(adap->status_file)) {
+ pr_warn("cec-%s: Failed to create status file\n", adap->name);
+ debugfs_remove_recursive(adap->cec_dir);
+ adap->cec_dir = NULL;
+ }
+#endif
+ return 0;
+}
+EXPORT_SYMBOL_GPL(cec_register_adapter);
+
+void cec_unregister_adapter(struct cec_adapter *adap)
+{
+ if (IS_ERR_OR_NULL(adap))
+ return;
+
+#if IS_ENABLED(CONFIG_RC_CORE)
+ /* Note: rc_unregister also calls rc_free */
+ rc_unregister_device(adap->rc);
+ adap->rc = NULL;
+#endif
+ debugfs_remove_recursive(adap->cec_dir);
+ cec_devnode_unregister(&adap->devnode);
+}
+EXPORT_SYMBOL_GPL(cec_unregister_adapter);
+
+void cec_delete_adapter(struct cec_adapter *adap)
+{
+ if (IS_ERR_OR_NULL(adap))
+ return;
+ mutex_lock(&adap->lock);
+ __cec_s_phys_addr(adap, CEC_PHYS_ADDR_INVALID, false);
+ mutex_unlock(&adap->lock);
+ kthread_stop(adap->kthread);
+ if (adap->kthread_config)
+ kthread_stop(adap->kthread_config);
+#if IS_ENABLED(CONFIG_RC_CORE)
+ if (adap->rc)
+ rc_free_device(adap->rc);
+#endif
+ kfree(adap);
+}
+EXPORT_SYMBOL_GPL(cec_delete_adapter);
+
+/*
+ * Initialise cec for linux
+ */
+static int __init cec_devnode_init(void)
+{
+ int ret;
+
+ pr_info("Linux cec interface: v0.10\n");
+ ret = alloc_chrdev_region(&cec_dev_t, 0, CEC_NUM_DEVICES,
+ CEC_NAME);
+ if (ret < 0) {
+ pr_warn("cec: unable to allocate major\n");
+ return ret;
+ }
+
+#ifdef CONFIG_MEDIA_CEC_DEBUG
+ top_cec_dir = debugfs_create_dir("cec", NULL);
+ if (IS_ERR_OR_NULL(top_cec_dir)) {
+ pr_warn("cec: Failed to create debugfs cec dir\n");
+ top_cec_dir = NULL;
+ }
+#endif
+
+ ret = bus_register(&cec_bus_type);
+ if (ret < 0) {
+ unregister_chrdev_region(cec_dev_t, CEC_NUM_DEVICES);
+ pr_warn("cec: bus_register failed\n");
+ return -EIO;
+ }
+
+ return 0;
+}
+
+static void __exit cec_devnode_exit(void)
+{
+ debugfs_remove_recursive(top_cec_dir);
+ bus_unregister(&cec_bus_type);
+ unregister_chrdev_region(cec_dev_t, CEC_NUM_DEVICES);
+}
+
+subsys_initcall(cec_devnode_init);
+module_exit(cec_devnode_exit)
+
+MODULE_AUTHOR("Hans Verkuil <hans.verkuil@cisco.com>");
+MODULE_DESCRIPTION("Device node registration for cec drivers");
+MODULE_LICENSE("GPL");
--- /dev/null
+/*
+ * cec - HDMI Consumer Electronics Control support header
+ *
+ * Copyright 2016 Cisco Systems, Inc. and/or its affiliates. All rights reserved.
+ *
+ * This program is free software; you may redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; version 2 of the License.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+ * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+ * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
+ * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
+ * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
+ * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+#ifndef _MEDIA_CEC_H
+#define _MEDIA_CEC_H
+
+#include <linux/poll.h>
+#include <linux/fs.h>
+#include <linux/debugfs.h>
+#include <linux/device.h>
+#include <linux/cdev.h>
+#include <linux/kthread.h>
+#include <linux/timer.h>
+#include <linux/cec-funcs.h>
+#include <media/rc-core.h>
+#include <media/cec-edid.h>
+
+/**
+ * struct cec_devnode - cec device node
+ * @dev: cec device
+ * @cdev: cec character device
+ * @parent: parent device
+ * @minor: device node minor number
+ * @registered: the device was correctly registered
+ * @unregistered: the device was unregistered
+ * @fhs_lock: lock to control access to the filehandle list
+ * @fhs: the list of open filehandles (cec_fh)
+ *
+ * This structure represents a cec-related device node.
+ *
+ * The @parent is a physical device. It must be set by core or device drivers
+ * before registering the node.
+ */
+struct cec_devnode {
+ /* sysfs */
+ struct device dev;
+ struct cdev cdev;
+ struct device *parent;
+
+ /* device info */
+ int minor;
+ bool registered;
+ bool unregistered;
+ struct mutex fhs_lock;
+ struct list_head fhs;
+};
+
+struct cec_adapter;
+struct cec_data;
+
+struct cec_data {
+ struct list_head list;
+ struct list_head xfer_list;
+ struct cec_adapter *adap;
+ struct cec_msg msg;
+ struct cec_fh *fh;
+ struct delayed_work work;
+ struct completion c;
+ u8 attempts;
+ bool new_initiator;
+ bool blocking;
+ bool completed;
+};
+
+struct cec_msg_entry {
+ struct list_head list;
+ struct cec_msg msg;
+};
+
+#define CEC_NUM_EVENTS CEC_EVENT_LOST_MSGS
+
+struct cec_fh {
+ struct list_head list;
+ struct list_head xfer_list;
+ struct cec_adapter *adap;
+ u8 mode_initiator;
+ u8 mode_follower;
+
+ /* Events */
+ wait_queue_head_t wait;
+ unsigned int pending_events;
+ struct cec_event events[CEC_NUM_EVENTS];
+ struct mutex lock;
+ struct list_head msgs; /* queued messages */
+ unsigned int queued_msgs;
+};
+
+#define CEC_SIGNAL_FREE_TIME_RETRY 3
+#define CEC_SIGNAL_FREE_TIME_NEW_INITIATOR 5
+#define CEC_SIGNAL_FREE_TIME_NEXT_XFER 7
+
+/* The nominal data bit period is 2.4 ms */
+#define CEC_FREE_TIME_TO_USEC(ft) ((ft) * 2400)
+
+struct cec_adap_ops {
+ /* Low-level callbacks */
+ int (*adap_enable)(struct cec_adapter *adap, bool enable);
+ int (*adap_monitor_all_enable)(struct cec_adapter *adap, bool enable);
+ int (*adap_log_addr)(struct cec_adapter *adap, u8 logical_addr);
+ int (*adap_transmit)(struct cec_adapter *adap, u8 attempts,
+ u32 signal_free_time, struct cec_msg *msg);
+ void (*adap_status)(struct cec_adapter *adap, struct seq_file *file);
+
+ /* High-level CEC message callback */
+ int (*received)(struct cec_adapter *adap, struct cec_msg *msg);
+};
+
+/*
+ * The minimum message length you can receive (excepting poll messages) is 2.
+ * With a transfer rate of at most 36 bytes per second this makes 18 messages
+ * per second worst case.
+ *
+ * We queue at most 3 seconds worth of messages. The CEC specification requires
+ * that messages are replied to within a second, so 3 seconds should give more
+ * than enough margin. Since most messages are actually more than 2 bytes, this
+ * is in practice a lot more than 3 seconds.
+ */
+#define CEC_MAX_MSG_QUEUE_SZ (18 * 3)
+
+struct cec_adapter {
+ struct module *owner;
+ char name[32];
+ struct cec_devnode devnode;
+ struct mutex lock;
+ struct rc_dev *rc;
+
+ struct list_head transmit_queue;
+ struct list_head wait_queue;
+ struct cec_data *transmitting;
+
+ struct task_struct *kthread_config;
+ struct completion config_completion;
+
+ struct task_struct *kthread;
+ wait_queue_head_t kthread_waitq;
+ wait_queue_head_t waitq;
+
+ const struct cec_adap_ops *ops;
+ void *priv;
+ u32 capabilities;
+ u8 available_log_addrs;
+
+ u16 phys_addr;
+ bool is_configuring;
+ bool is_configured;
+ u32 monitor_all_cnt;
+ u32 follower_cnt;
+ struct cec_fh *cec_follower;
+ struct cec_fh *cec_initiator;
+ bool passthrough;
+ struct cec_log_addrs log_addrs;
+
+ struct dentry *cec_dir;
+ struct dentry *status_file;
+
+ u16 phys_addrs[15];
+ u32 sequence;
+
+ char input_name[32];
+ char input_phys[32];
+ char input_drv[32];
+};
+
+static inline bool cec_has_log_addr(const struct cec_adapter *adap, u8 log_addr)
+{
+ return adap->log_addrs.log_addr_mask & (1 << log_addr);
+}
+
+static inline bool cec_is_sink(const struct cec_adapter *adap)
+{
+ return adap->phys_addr == 0;
+}
+
+#if IS_ENABLED(CONFIG_MEDIA_CEC)
+struct cec_adapter *cec_allocate_adapter(const struct cec_adap_ops *ops,
+ void *priv, const char *name, u32 caps, u8 available_las,
+ struct device *parent);
+int cec_register_adapter(struct cec_adapter *adap);
+void cec_unregister_adapter(struct cec_adapter *adap);
+void cec_delete_adapter(struct cec_adapter *adap);
+
+int cec_s_log_addrs(struct cec_adapter *adap, struct cec_log_addrs *log_addrs,
+ bool block);
+void cec_s_phys_addr(struct cec_adapter *adap, u16 phys_addr,
+ bool block);
+int cec_transmit_msg(struct cec_adapter *adap, struct cec_msg *msg,
+ bool block);
+
+/* Called by the adapter */
+void cec_transmit_done(struct cec_adapter *adap, u8 status, u8 arb_lost_cnt,
+ u8 nack_cnt, u8 low_drive_cnt, u8 error_cnt);
+void cec_received_msg(struct cec_adapter *adap, struct cec_msg *msg);
+
+#else
+
+static inline int cec_register_adapter(struct cec_adapter *adap)
+{
+ return 0;
+}
+
+static inline void cec_unregister_adapter(struct cec_adapter *adap)
+{
+}
+
+static inline void cec_delete_adapter(struct cec_adapter *adap)
+{
+}
+
+static inline void cec_s_phys_addr(struct cec_adapter *adap, u16 phys_addr,
+ bool block)
+{
+}
+
+#endif
+
+#endif /* _MEDIA_CEC_H */
projects / mirror_ubuntu-bionic-kernel.git / commitdiff