1 files changed, 412 insertions, 0 deletions

diff --git a/drivers/media/cec/cec-core.c b/drivers/media/cec/cec-core.c
new file mode 100644
index 000000000000..37217e205040
--- /dev/null
+++ b/drivers/media/cec/cec-core.c
@@ -0,0 +1,412 @@
+/*
+ * 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 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(&devnode->lock);
+	/*
+	 * return ENXIO if the cec device has been removed
+	 * already or if it is not registered anymore.
+	 */
+	if (!devnode->registered) {
+		mutex_unlock(&devnode->lock);
+		return -ENXIO;
+	}
+	/* and increase the device refcount */
+	get_device(&devnode->dev);
+	mutex_unlock(&devnode->lock);
+	return 0;
+}
+
+void cec_put_device(struct cec_devnode *devnode)
+{
+	put_device(&devnode->dev);
+}
+
+/* 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->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;
+	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:
+	mutex_lock(&cec_devnode_lock);
+	clear_bit(devnode->minor, cec_devnode_nums);
+	mutex_unlock(&cec_devnode_lock);
+	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;
+
+	mutex_lock(&devnode->lock);
+
+	/* Check if devnode was never registered or already unregistered */
+	if (!devnode->registered || devnode->unregistered) {
+		mutex_unlock(&devnode->lock);
+		return;
+	}
+
+	list_for_each_entry(fh, &devnode->fhs, list)
+		wake_up_interruptible(&fh->wait);
+
+	devnode->registered = false;
+	devnode->unregistered = true;
+	mutex_unlock(&devnode->lock);
+
+	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 cec_adapter *adap;
+	int res;
+
+	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);
+	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_REACHABLE(CONFIG_RC_CORE)
+	/* Prepare the RC input device */
+	adap->rc = rc_allocate_device(RC_DRIVER_SCANCODE);
+	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->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,
+			 struct device *parent)
+{
+	int res;
+
+	if (IS_ERR_OR_NULL(adap))
+		return 0;
+
+	if (WARN_ON(!parent))
+		return -EINVAL;
+
+	adap->owner = parent->driver->owner;
+	adap->devnode.dev.parent = parent;
+
+#if IS_REACHABLE(CONFIG_RC_CORE)
+	adap->rc->dev.parent = parent;
+	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_REACHABLE(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_REACHABLE(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_REACHABLE(CONFIG_RC_CORE)
+	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");