[media] cec: move the CEC framework out of staging and to media

The last open issues have been addressed, so it is time to move
this out of staging and into the mainline and to move the public
cec headers to include/uapi/linux.

Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>

1 files changed, 411 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..b0137e247dc9
--- /dev/null
+++ b/drivers/media/cec/cec-core.c
@@ -0,0 +1,411 @@
+/*
+ * 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;
+	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:
+	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 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_REACHABLE(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_REACHABLE(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_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");