[linux-2.6-block.git] / drivers / platform / chrome / cros_ec_dev.c

/*
 * cros_ec_dev - expose the Chrome OS Embedded Controller to user-space
 *
 * Copyright (C) 2014 Google, Inc.
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program. If not, see <http://www.gnu.org/licenses/>.
 */

#include <linux/fs.h>
#include <linux/module.h>
#include <linux/platform_device.h>
#include <linux/slab.h>
#include <linux/uaccess.h>

#include "cros_ec_dev.h"

/* Device variables */
#define CROS_MAX_DEV 128
static int ec_major;

static const struct attribute_group *cros_ec_groups[] = {
	&cros_ec_attr_group,
	&cros_ec_lightbar_attr_group,
	&cros_ec_vbc_attr_group,
	NULL,
};

static struct class cros_class = {
	.owner          = THIS_MODULE,
	.name           = "chromeos",
	.dev_groups     = cros_ec_groups,
};

/* Basic communication */
static int ec_get_version(struct cros_ec_dev *ec, char *str, int maxlen)
{
	struct ec_response_get_version *resp;
	static const char * const current_image_name[] = {
		"unknown", "read-only", "read-write", "invalid",
	};
	struct cros_ec_command *msg;
	int ret;

	msg = kmalloc(sizeof(*msg) + sizeof(*resp), GFP_KERNEL);
	if (!msg)
		return -ENOMEM;

	msg->version = 0;
	msg->command = EC_CMD_GET_VERSION + ec->cmd_offset;
	msg->insize = sizeof(*resp);
	msg->outsize = 0;

	ret = cros_ec_cmd_xfer(ec->ec_dev, msg);
	if (ret < 0)
		goto exit;

	if (msg->result != EC_RES_SUCCESS) {
		snprintf(str, maxlen,
			 "%s\nUnknown EC version: EC returned %d\n",
			 CROS_EC_DEV_VERSION, msg->result);
		ret = -EINVAL;
		goto exit;
	}

	resp = (struct ec_response_get_version *)msg->data;
	if (resp->current_image >= ARRAY_SIZE(current_image_name))
		resp->current_image = 3; /* invalid */

	snprintf(str, maxlen, "%s\n%s\n%s\n%s\n", CROS_EC_DEV_VERSION,
		 resp->version_string_ro, resp->version_string_rw,
		 current_image_name[resp->current_image]);

	ret = 0;
exit:
	kfree(msg);
	return ret;
}

/* Device file ops */
static int ec_device_open(struct inode *inode, struct file *filp)
{
	struct cros_ec_dev *ec = container_of(inode->i_cdev,
					      struct cros_ec_dev, cdev);
	filp->private_data = ec;
	nonseekable_open(inode, filp);
	return 0;
}

static int ec_device_release(struct inode *inode, struct file *filp)
{
	return 0;
}

static ssize_t ec_device_read(struct file *filp, char __user *buffer,
			      size_t length, loff_t *offset)
{
	struct cros_ec_dev *ec = filp->private_data;
	char msg[sizeof(struct ec_response_get_version) +
		 sizeof(CROS_EC_DEV_VERSION)];
	size_t count;
	int ret;

	if (*offset != 0)
		return 0;

	ret = ec_get_version(ec, msg, sizeof(msg));
	if (ret)
		return ret;

	count = min(length, strlen(msg));

	if (copy_to_user(buffer, msg, count))
		return -EFAULT;

	*offset = count;
	return count;
}

/* Ioctls */
static long ec_device_ioctl_xcmd(struct cros_ec_dev *ec, void __user *arg)
{
	long ret;
	struct cros_ec_command u_cmd;
	struct cros_ec_command *s_cmd;

	if (copy_from_user(&u_cmd, arg, sizeof(u_cmd)))
		return -EFAULT;

	if ((u_cmd.outsize > EC_MAX_MSG_BYTES) ||
	    (u_cmd.insize > EC_MAX_MSG_BYTES))
		return -EINVAL;

	s_cmd = kmalloc(sizeof(*s_cmd) + max(u_cmd.outsize, u_cmd.insize),
			GFP_KERNEL);
	if (!s_cmd)
		return -ENOMEM;

	if (copy_from_user(s_cmd, arg, sizeof(*s_cmd) + u_cmd.outsize)) {
		ret = -EFAULT;
		goto exit;
	}

	if (u_cmd.outsize != s_cmd->outsize ||
	    u_cmd.insize != s_cmd->insize) {
		ret = -EINVAL;
		goto exit;
	}

	s_cmd->command += ec->cmd_offset;
	ret = cros_ec_cmd_xfer(ec->ec_dev, s_cmd);
	/* Only copy data to userland if data was received. */
	if (ret < 0)
		goto exit;

	if (copy_to_user(arg, s_cmd, sizeof(*s_cmd) + s_cmd->insize))
		ret = -EFAULT;
exit:
	kfree(s_cmd);
	return ret;
}

static long ec_device_ioctl_readmem(struct cros_ec_dev *ec, void __user *arg)
{
	struct cros_ec_device *ec_dev = ec->ec_dev;
	struct cros_ec_readmem s_mem = { };
	long num;

	/* Not every platform supports direct reads */
	if (!ec_dev->cmd_readmem)
		return -ENOTTY;

	if (copy_from_user(&s_mem, arg, sizeof(s_mem)))
		return -EFAULT;

	num = ec_dev->cmd_readmem(ec_dev, s_mem.offset, s_mem.bytes,
				  s_mem.buffer);
	if (num <= 0)
		return num;

	if (copy_to_user((void __user *)arg, &s_mem, sizeof(s_mem)))
		return -EFAULT;

	return 0;
}

static long ec_device_ioctl(struct file *filp, unsigned int cmd,
			    unsigned long arg)
{
	struct cros_ec_dev *ec = filp->private_data;

	if (_IOC_TYPE(cmd) != CROS_EC_DEV_IOC)
		return -ENOTTY;

	switch (cmd) {
	case CROS_EC_DEV_IOCXCMD:
		return ec_device_ioctl_xcmd(ec, (void __user *)arg);
	case CROS_EC_DEV_IOCRDMEM:
		return ec_device_ioctl_readmem(ec, (void __user *)arg);
	}

	return -ENOTTY;
}

/* Module initialization */
static const struct file_operations fops = {
	.open = ec_device_open,
	.release = ec_device_release,
	.read = ec_device_read,
	.unlocked_ioctl = ec_device_ioctl,
#ifdef CONFIG_COMPAT
	.compat_ioctl = ec_device_ioctl,
#endif
};

static void __remove(struct device *dev)
{
	struct cros_ec_dev *ec = container_of(dev, struct cros_ec_dev,
					      class_dev);
	kfree(ec);
}

static int ec_device_probe(struct platform_device *pdev)
{
	int retval = -ENOMEM;
	struct device *dev = &pdev->dev;
	struct cros_ec_platform *ec_platform = dev_get_platdata(dev);
	dev_t devno = MKDEV(ec_major, pdev->id);
	struct cros_ec_dev *ec = kzalloc(sizeof(*ec), GFP_KERNEL);

	if (!ec)
		return retval;

	dev_set_drvdata(dev, ec);
	ec->ec_dev = dev_get_drvdata(dev->parent);
	ec->dev = dev;
	ec->cmd_offset = ec_platform->cmd_offset;
	device_initialize(&ec->class_dev);
	cdev_init(&ec->cdev, &fops);

	/*
	 * Add the character device
	 * Link cdev to the class device to be sure device is not used
	 * before unbinding it.
	 */
	ec->cdev.kobj.parent = &ec->class_dev.kobj;
	retval = cdev_add(&ec->cdev, devno, 1);
	if (retval) {
		dev_err(dev, ": failed to add character device\n");
		goto cdev_add_failed;
	}

	/*
	 * Add the class device
	 * Link to the character device for creating the /dev entry
	 * in devtmpfs.
	 */
	ec->class_dev.devt = ec->cdev.dev;
	ec->class_dev.class = &cros_class;
	ec->class_dev.parent = dev;
	ec->class_dev.release = __remove;

	retval = dev_set_name(&ec->class_dev, "%s", ec_platform->ec_name);
	if (retval) {
		dev_err(dev, "dev_set_name failed => %d\n", retval);
		goto set_named_failed;
	}

	retval = device_add(&ec->class_dev);
	if (retval) {
		dev_err(dev, "device_register failed => %d\n", retval);
		goto dev_reg_failed;
	}

	return 0;

dev_reg_failed:
set_named_failed:
	dev_set_drvdata(dev, NULL);
	cdev_del(&ec->cdev);
cdev_add_failed:
	kfree(ec);
	return retval;
}

static int ec_device_remove(struct platform_device *pdev)
{
	struct cros_ec_dev *ec = dev_get_drvdata(&pdev->dev);
	cdev_del(&ec->cdev);
	device_unregister(&ec->class_dev);
	return 0;
}

static const struct platform_device_id cros_ec_id[] = {
	{ "cros-ec-ctl", 0 },
	{ /* sentinel */ },
};
MODULE_DEVICE_TABLE(platform, cros_ec_id);

static struct platform_driver cros_ec_dev_driver = {
	.driver = {
		.name = "cros-ec-ctl",
	},
	.probe = ec_device_probe,
	.remove = ec_device_remove,
};

static int __init cros_ec_dev_init(void)
{
	int ret;
	dev_t dev = 0;

	ret  = class_register(&cros_class);
	if (ret) {
		pr_err(CROS_EC_DEV_NAME ": failed to register device class\n");
		return ret;
	}

	/* Get a range of minor numbers (starting with 0) to work with */
	ret = alloc_chrdev_region(&dev, 0, CROS_MAX_DEV, CROS_EC_DEV_NAME);
	if (ret < 0) {
		pr_err(CROS_EC_DEV_NAME ": alloc_chrdev_region() failed\n");
		goto failed_chrdevreg;
	}
	ec_major = MAJOR(dev);

	/* Register the driver */
	ret = platform_driver_register(&cros_ec_dev_driver);
	if (ret < 0) {
		pr_warn(CROS_EC_DEV_NAME ": can't register driver: %d\n", ret);
		goto failed_devreg;
	}
	return 0;

failed_devreg:
	unregister_chrdev_region(MKDEV(ec_major, 0), CROS_MAX_DEV);
failed_chrdevreg:
	class_unregister(&cros_class);
	return ret;
}

static void __exit cros_ec_dev_exit(void)
{
	platform_driver_unregister(&cros_ec_dev_driver);
	unregister_chrdev(ec_major, CROS_EC_DEV_NAME);
	class_unregister(&cros_class);
}

module_init(cros_ec_dev_init);
module_exit(cros_ec_dev_exit);

MODULE_AUTHOR("Bill Richardson <wfrichar@chromium.org>");
MODULE_DESCRIPTION("Userspace interface to the Chrome OS Embedded Controller");
MODULE_VERSION("1.0");
MODULE_LICENSE("GPL");
Commit	Line	Data
e7c256fb BR	1	/*
	2	* cros_ec_dev - expose the Chrome OS Embedded Controller to user-space
	3	*
	4	* Copyright (C) 2014 Google, Inc.
	5	*
	6	* This program is free software; you can redistribute it and/or modify
	7	* it under the terms of the GNU General Public License as published by
	8	* the Free Software Foundation; either version 2 of the License, or
	9	* (at your option) any later version.
	10	*
	11	* This program is distributed in the hope that it will be useful,
	12	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	13	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	14	* GNU General Public License for more details.
	15	*
	16	* You should have received a copy of the GNU General Public License
	17	* along with this program. If not, see <http://www.gnu.org/licenses/>.
	18	*/
	19
	20	#include <linux/fs.h>
	21	#include <linux/module.h>
	22	#include <linux/platform_device.h>
a8411784	23	#include <linux/slab.h>
e7c256fb BR	24	#include <linux/uaccess.h>
	25
	26	#include "cros_ec_dev.h"
	27
	28	/* Device variables */
	29	#define CROS_MAX_DEV 128
e7c256fb BR	30	static int ec_major;
e7c256fb BR	31
57b33ff0 GG	32	static const struct attribute_group *cros_ec_groups[] = {
	33	&cros_ec_attr_group,
	34	&cros_ec_lightbar_attr_group,
18800fc7	35	&cros_ec_vbc_attr_group,
57b33ff0 GG	36	NULL,
	37	};
	38
	39	static struct class cros_class = {
	40	.owner = THIS_MODULE,
	41	.name = "chromeos",
	42	.dev_groups = cros_ec_groups,
	43	};
	44
e7c256fb	45	/* Basic communication */
57b33ff0	46	static int ec_get_version(struct cros_ec_dev ec, char str, int maxlen)
e7c256fb BR	47	{
	48	struct ec_response_get_version *resp;
	49	static const char * const current_image_name[] = {
	50	"unknown", "read-only", "read-write", "invalid",
	51	};
a8411784	52	struct cros_ec_command *msg;
e7c256fb BR	53	int ret;
e7c256fb BR	54
a8411784 JMC	55	msg = kmalloc(sizeof(msg) + sizeof(resp), GFP_KERNEL);
	56	if (!msg)
	57	return -ENOMEM;
	58
	59	msg->version = 0;
57b33ff0	60	msg->command = EC_CMD_GET_VERSION + ec->cmd_offset;
a8411784 JMC	61	msg->insize = sizeof(*resp);
	62	msg->outsize = 0;
	63
57b33ff0	64	ret = cros_ec_cmd_xfer(ec->ec_dev, msg);
e7c256fb	65	if (ret < 0)
a8411784	66	goto exit;
e7c256fb	67
a8411784	68	if (msg->result != EC_RES_SUCCESS) {
e7c256fb BR	69	snprintf(str, maxlen,
e7c256fb BR	70	"%s\nUnknown EC version: EC returned %d\n",
a8411784 JMC	71	CROS_EC_DEV_VERSION, msg->result);
	72	ret = -EINVAL;
	73	goto exit;
e7c256fb BR	74	}
e7c256fb BR	75
a8411784	76	resp = (struct ec_response_get_version *)msg->data;
e7c256fb BR	77	if (resp->current_image >= ARRAY_SIZE(current_image_name))
	78	resp->current_image = 3; /* invalid */
	79
ef59c25d	80	snprintf(str, maxlen, "%s\n%s\n%s\n%s\n", CROS_EC_DEV_VERSION,
e7c256fb BR	81	resp->version_string_ro, resp->version_string_rw,
	82	current_image_name[resp->current_image]);
	83
a8411784 JMC	84	ret = 0;
	85	exit:
	86	kfree(msg);
	87	return ret;
e7c256fb BR	88	}
	89
	90	/* Device file ops */
	91	static int ec_device_open(struct inode inode, struct file filp)
	92	{
57b33ff0 GG	93	struct cros_ec_dev *ec = container_of(inode->i_cdev,
	94	struct cros_ec_dev, cdev);
	95	filp->private_data = ec;
	96	nonseekable_open(inode, filp);
e7c256fb BR	97	return 0;
	98	}
	99
	100	static int ec_device_release(struct inode inode, struct file filp)
	101	{
	102	return 0;
	103	}
	104
	105	static ssize_t ec_device_read(struct file filp, char __user buffer,
	106	size_t length, loff_t *offset)
	107	{
57b33ff0	108	struct cros_ec_dev *ec = filp->private_data;
e7c256fb BR	109	char msg[sizeof(struct ec_response_get_version) +
	110	sizeof(CROS_EC_DEV_VERSION)];
	111	size_t count;
	112	int ret;
	113
	114	if (*offset != 0)
	115	return 0;
	116
	117	ret = ec_get_version(ec, msg, sizeof(msg));
	118	if (ret)
	119	return ret;
	120
	121	count = min(length, strlen(msg));
	122
	123	if (copy_to_user(buffer, msg, count))
	124	return -EFAULT;
	125
	126	*offset = count;
	127	return count;
	128	}
	129
	130	/* Ioctls */
57b33ff0	131	static long ec_device_ioctl_xcmd(struct cros_ec_dev ec, void __user arg)
e7c256fb BR	132	{
e7c256fb BR	133	long ret;
a8411784 JMC	134	struct cros_ec_command u_cmd;
a8411784 JMC	135	struct cros_ec_command *s_cmd;
e7c256fb	136
a8411784	137	if (copy_from_user(&u_cmd, arg, sizeof(u_cmd)))
e7c256fb BR	138	return -EFAULT;
e7c256fb BR	139
5d749d0b GG	140	if ((u_cmd.outsize > EC_MAX_MSG_BYTES) \|\|
	141	(u_cmd.insize > EC_MAX_MSG_BYTES))
	142	return -EINVAL;
	143
a8411784 JMC	144	s_cmd = kmalloc(sizeof(*s_cmd) + max(u_cmd.outsize, u_cmd.insize),
	145	GFP_KERNEL);
	146	if (!s_cmd)
	147	return -ENOMEM;
	148
	149	if (copy_from_user(s_cmd, arg, sizeof(*s_cmd) + u_cmd.outsize)) {
	150	ret = -EFAULT;
	151	goto exit;
	152	}
	153
096cdc6f DC	154	if (u_cmd.outsize != s_cmd->outsize \|\|
	155	u_cmd.insize != s_cmd->insize) {
	156	ret = -EINVAL;
	157	goto exit;
	158	}
	159
57b33ff0 GG	160	s_cmd->command += ec->cmd_offset;
57b33ff0 GG	161	ret = cros_ec_cmd_xfer(ec->ec_dev, s_cmd);
e7c256fb BR	162	/* Only copy data to userland if data was received. */
e7c256fb BR	163	if (ret < 0)
a8411784	164	goto exit;
e7c256fb	165
096cdc6f	166	if (copy_to_user(arg, s_cmd, sizeof(*s_cmd) + s_cmd->insize))
a8411784 JMC	167	ret = -EFAULT;
	168	exit:
	169	kfree(s_cmd);
	170	return ret;
e7c256fb BR	171	}
e7c256fb BR	172
57b33ff0	173	static long ec_device_ioctl_readmem(struct cros_ec_dev ec, void __user arg)
e7c256fb	174	{
57b33ff0	175	struct cros_ec_device *ec_dev = ec->ec_dev;
e7c256fb BR	176	struct cros_ec_readmem s_mem = { };
	177	long num;
	178
	179	/* Not every platform supports direct reads */
57b33ff0	180	if (!ec_dev->cmd_readmem)
e7c256fb BR	181	return -ENOTTY;
	182
	183	if (copy_from_user(&s_mem, arg, sizeof(s_mem)))
	184	return -EFAULT;
	185
57b33ff0 GG	186	num = ec_dev->cmd_readmem(ec_dev, s_mem.offset, s_mem.bytes,
57b33ff0 GG	187	s_mem.buffer);
e7c256fb BR	188	if (num <= 0)
	189	return num;
	190
	191	if (copy_to_user((void __user *)arg, &s_mem, sizeof(s_mem)))
	192	return -EFAULT;
	193
	194	return 0;
	195	}
	196
	197	static long ec_device_ioctl(struct file *filp, unsigned int cmd,
	198	unsigned long arg)
	199	{
57b33ff0	200	struct cros_ec_dev *ec = filp->private_data;
e7c256fb BR	201
	202	if (_IOC_TYPE(cmd) != CROS_EC_DEV_IOC)
	203	return -ENOTTY;
	204
	205	switch (cmd) {
	206	case CROS_EC_DEV_IOCXCMD:
	207	return ec_device_ioctl_xcmd(ec, (void __user *)arg);
	208	case CROS_EC_DEV_IOCRDMEM:
	209	return ec_device_ioctl_readmem(ec, (void __user *)arg);
	210	}
	211
	212	return -ENOTTY;
	213	}
	214
	215	/* Module initialization */
	216	static const struct file_operations fops = {
	217	.open = ec_device_open,
	218	.release = ec_device_release,
	219	.read = ec_device_read,
	220	.unlocked_ioctl = ec_device_ioctl,
2521ea3e GR	221	#ifdef CONFIG_COMPAT
	222	.compat_ioctl = ec_device_ioctl,
	223	#endif
e7c256fb BR	224	};
e7c256fb BR	225
57b33ff0 GG	226	static void __remove(struct device *dev)
	227	{
	228	struct cros_ec_dev *ec = container_of(dev, struct cros_ec_dev,
	229	class_dev);
	230	kfree(ec);
	231	}
	232
e7c256fb BR	233	static int ec_device_probe(struct platform_device *pdev)
e7c256fb BR	234	{
57b33ff0 GG	235	int retval = -ENOMEM;
	236	struct device *dev = &pdev->dev;
	237	struct cros_ec_platform *ec_platform = dev_get_platdata(dev);
	238	dev_t devno = MKDEV(ec_major, pdev->id);
	239	struct cros_ec_dev ec = kzalloc(sizeof(ec), GFP_KERNEL);
	240
	241	if (!ec)
	242	return retval;
e7c256fb	243
57b33ff0 GG	244	dev_set_drvdata(dev, ec);
	245	ec->ec_dev = dev_get_drvdata(dev->parent);
	246	ec->dev = dev;
	247	ec->cmd_offset = ec_platform->cmd_offset;
	248	device_initialize(&ec->class_dev);
e7c256fb BR	249	cdev_init(&ec->cdev, &fops);
e7c256fb BR	250
57b33ff0 GG	251	/*
	252	* Add the character device
	253	* Link cdev to the class device to be sure device is not used
	254	* before unbinding it.
	255	*/
	256	ec->cdev.kobj.parent = &ec->class_dev.kobj;
e7c256fb BR	257	retval = cdev_add(&ec->cdev, devno, 1);
e7c256fb BR	258	if (retval) {
57b33ff0 GG	259	dev_err(dev, ": failed to add character device\n");
57b33ff0 GG	260	goto cdev_add_failed;
e7c256fb BR	261	}
e7c256fb BR	262
57b33ff0 GG	263	/*
	264	* Add the class device
	265	* Link to the character device for creating the /dev entry
	266	* in devtmpfs.
	267	*/
	268	ec->class_dev.devt = ec->cdev.dev;
	269	ec->class_dev.class = &cros_class;
	270	ec->class_dev.parent = dev;
	271	ec->class_dev.release = __remove;
	272
	273	retval = dev_set_name(&ec->class_dev, "%s", ec_platform->ec_name);
	274	if (retval) {
	275	dev_err(dev, "dev_set_name failed => %d\n", retval);
	276	goto set_named_failed;
e7c256fb BR	277	}
e7c256fb BR	278
57b33ff0 GG	279	retval = device_add(&ec->class_dev);
	280	if (retval) {
	281	dev_err(dev, "device_register failed => %d\n", retval);
	282	goto dev_reg_failed;
	283	}
71af4b52	284
e7c256fb	285	return 0;
57b33ff0 GG	286
	287	dev_reg_failed:
	288	set_named_failed:
	289	dev_set_drvdata(dev, NULL);
	290	cdev_del(&ec->cdev);
	291	cdev_add_failed:
	292	kfree(ec);
	293	return retval;
e7c256fb BR	294	}
	295
	296	static int ec_device_remove(struct platform_device *pdev)
	297	{
57b33ff0	298	struct cros_ec_dev *ec = dev_get_drvdata(&pdev->dev);
e7c256fb	299	cdev_del(&ec->cdev);
57b33ff0	300	device_unregister(&ec->class_dev);
e7c256fb BR	301	return 0;
	302	}
	303
afbf8ec7 JMC	304	static const struct platform_device_id cros_ec_id[] = {
	305	{ "cros-ec-ctl", 0 },
	306	{ /* sentinel */ },
	307	};
	308	MODULE_DEVICE_TABLE(platform, cros_ec_id);
	309
e7c256fb BR	310	static struct platform_driver cros_ec_dev_driver = {
	311	.driver = {
	312	.name = "cros-ec-ctl",
	313	},
	314	.probe = ec_device_probe,
	315	.remove = ec_device_remove,
	316	};
	317
	318	static int __init cros_ec_dev_init(void)
	319	{
	320	int ret;
	321	dev_t dev = 0;
	322
57b33ff0 GG	323	ret = class_register(&cros_class);
57b33ff0 GG	324	if (ret) {
e7c256fb	325	pr_err(CROS_EC_DEV_NAME ": failed to register device class\n");
57b33ff0	326	return ret;
e7c256fb BR	327	}
	328
	329	/* Get a range of minor numbers (starting with 0) to work with */
	330	ret = alloc_chrdev_region(&dev, 0, CROS_MAX_DEV, CROS_EC_DEV_NAME);
	331	if (ret < 0) {
	332	pr_err(CROS_EC_DEV_NAME ": alloc_chrdev_region() failed\n");
	333	goto failed_chrdevreg;
	334	}
	335	ec_major = MAJOR(dev);
	336
	337	/* Register the driver */
	338	ret = platform_driver_register(&cros_ec_dev_driver);
	339	if (ret < 0) {
	340	pr_warn(CROS_EC_DEV_NAME ": can't register driver: %d\n", ret);
	341	goto failed_devreg;
	342	}
	343	return 0;
	344
	345	failed_devreg:
	346	unregister_chrdev_region(MKDEV(ec_major, 0), CROS_MAX_DEV);
	347	failed_chrdevreg:
57b33ff0	348	class_unregister(&cros_class);
e7c256fb BR	349	return ret;
	350	}
	351
	352	static void __exit cros_ec_dev_exit(void)
	353	{
	354	platform_driver_unregister(&cros_ec_dev_driver);
	355	unregister_chrdev(ec_major, CROS_EC_DEV_NAME);
57b33ff0	356	class_unregister(&cros_class);
e7c256fb BR	357	}
	358
	359	module_init(cros_ec_dev_init);
	360	module_exit(cros_ec_dev_exit);
	361
	362	MODULE_AUTHOR("Bill Richardson <wfrichar@chromium.org>");
	363	MODULE_DESCRIPTION("Userspace interface to the Chrome OS Embedded Controller");
	364	MODULE_VERSION("1.0");
	365	MODULE_LICENSE("GPL");