drivers/mfd/cros_ec_debugfs.c - chromiumos/third_party/kernel - Git at Google

 /*
  * cros_ec_debugfs - debug logs for Chrome OS EC
  *
  * Copyright 2015 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/circ_buf.h>
 #include <linux/debugfs.h>
 #include <linux/delay.h>
 #include <linux/fs.h>
 #include <linux/mfd/cros_ec.h>
 #include <linux/mfd/cros_ec_commands.h>
 #include <linux/mfd/cros_ec_dev.h>
 #include <linux/mutex.h>
 #include <linux/poll.h>
 #include <linux/sched.h>
 #include <linux/slab.h>
 #include <linux/wait.h>

 #include "cros_ec_debugfs.h"

 #define LOG_SHIFT		14
 #define LOG_SIZE		(1 << LOG_SHIFT)
 #define LOG_POLL_SEC		10

 #define CIRC_ADD(idx, size, value)	(((idx) + (value)) & ((size) - 1))

 /* struct cros_ec_debugfs - ChromeOS EC debugging information
  *
  * @ec: EC device this debugfs information belongs to
  * @dir: dentry for debugfs files
  * @log_buffer: circular buffer for console log information
  * @ec_buffer: buffer used to read console log from EC
  * @ec_buffer_size: size of that buffer
  * @log_mutex: mutex to protect circular buffer
  * @log_wq: waitqueue for log readers
  * @log_poll_work: recurring task to poll EC for new console log data
  * @panicinfo_blob: panicinfo debugfs blob
  */
 struct cros_ec_debugfs {
 	struct cros_ec_dev *ec;
 	struct dentry *dir;
 	/* EC log */
 	struct circ_buf log_buffer;
 	uint8_t *ec_buffer;
 	size_t ec_buffer_size;
 	struct mutex log_mutex;
 	wait_queue_head_t log_wq;
 	struct delayed_work log_poll_work;
 	/* EC panicinfo */
 	struct debugfs_blob_wrapper panicinfo_blob;
 };

 /*
  * TODO(ejcaruso): Move this from a recurring task to being triggered by
  * host events in the future. For now, this should expose a stable interface
  * for a userspace log concatenator.
  *
  * Note: We also need to make sure that the EC log on the UART is large enough,
  * so that it is unlikely enough to overlow within LOG_POLL_SEC.
  */
 static void cros_ec_console_log_work(struct work_struct *__work)
 {
 	struct cros_ec_debugfs *debug_info =
 		container_of(to_delayed_work(__work),
 			     struct cros_ec_debugfs,
 			     log_poll_work);
 	struct cros_ec_dev *ec = debug_info->ec;
 	struct circ_buf *cb = &debug_info->log_buffer;
 	struct cros_ec_command snapshot_msg = {
 		.command = EC_CMD_CONSOLE_SNAPSHOT + ec->cmd_offset,
 	};

 	struct ec_params_console_read_v1 params = {
 		.subcmd = CONSOLE_READ_RECENT,
 	};

 	struct cros_ec_command read_msg = {
 		.version = 1,
 		.command = EC_CMD_CONSOLE_READ + ec->cmd_offset,
 		.outdata = (void *)&params,
 		.outsize = sizeof(params),
 		.indata = debug_info->ec_buffer,
 		.insize = debug_info->ec_buffer_size,
 	};

 	int idx;
 	int buf_space;
 	int ret;

 	ret = cros_ec_cmd_xfer(ec->ec_dev, &snapshot_msg);
 	if (ret < 0) {
 		dev_err(ec->dev, "EC communication failed\n");
 		goto resched;
 	}
 	if (snapshot_msg.result != EC_RES_SUCCESS) {
 		dev_err(ec->dev, "EC failed to snapshot the console log\n");
 		goto resched;
 	}

 	/* Loop until we have read everything, or there's an error. */
 	mutex_lock(&debug_info->log_mutex);
 	buf_space = CIRC_SPACE(cb->head, cb->tail, LOG_SIZE);

 	while (1) {
 		if (!buf_space) {
 			dev_info_once(ec->dev,
 				      "Some logs may have been dropped...\n");
 			break;
 		}

 		memset(debug_info->ec_buffer, '\0', debug_info->ec_buffer_size);
 		ret = cros_ec_cmd_xfer(ec->ec_dev, &read_msg);
 		if (ret < 0) {
 			dev_err(ec->dev, "EC communication failed\n");
 			break;
 		}
 		if (read_msg.result != EC_RES_SUCCESS) {
 			dev_err(ec->dev,
 				"EC failed to read the console log\n");
 			break;
 		}

 		/* If the buffer is empty, we're done here. */
 		if (debug_info->ec_buffer[0] == '\0')
 			break;

 		idx = 0;
 		while (idx < debug_info->ec_buffer_size &&
 		       debug_info->ec_buffer[idx] != '\0' &&
 		       buf_space > 0) {
 			cb->buf[cb->head] = debug_info->ec_buffer[idx];
 			cb->head = CIRC_ADD(cb->head, LOG_SIZE, 1);
 			idx++;
 			buf_space--;
 		}

 		wake_up(&debug_info->log_wq);
 	}

 	mutex_unlock(&debug_info->log_mutex);

 resched:
 	schedule_delayed_work(&debug_info->log_poll_work,
 			      msecs_to_jiffies(LOG_POLL_SEC * 1000));
 }

 static int cros_ec_console_log_open(struct inode *inode, struct file *file)
 {
 	file->private_data = inode->i_private;

 	return nonseekable_open(inode, file);
 }

 static ssize_t cros_ec_console_log_read(struct file *file, char __user *buf,
 					size_t count, loff_t *ppos)
 {
 	struct cros_ec_debugfs *debug_info = file->private_data;
 	struct circ_buf *cb = &debug_info->log_buffer;
 	ssize_t ret;

 	mutex_lock(&debug_info->log_mutex);

 	while (!CIRC_CNT(cb->head, cb->tail, LOG_SIZE)) {
 		if (file->f_flags & O_NONBLOCK) {
 			ret = -EAGAIN;
 			goto error;
 		}

 		mutex_unlock(&debug_info->log_mutex);

 		ret = wait_event_interruptible(debug_info->log_wq,
 					CIRC_CNT(cb->head, cb->tail, LOG_SIZE));
 		if (ret < 0)
 			return ret;

 		mutex_lock(&debug_info->log_mutex);
 	}

 	/* Only copy until the end of the circular buffer, and let userspace
 	 * retry to get the rest of the data.
 	 */
 	ret = min_t(size_t, CIRC_CNT_TO_END(cb->head, cb->tail, LOG_SIZE),
 		    count);

 	if (copy_to_user(buf, cb->buf + cb->tail, ret)) {
 		ret = -EFAULT;
 		goto error;
 	}

 	cb->tail = CIRC_ADD(cb->tail, LOG_SIZE, ret);

 error:
 	mutex_unlock(&debug_info->log_mutex);
 	return ret;
 }

 static unsigned int cros_ec_console_log_poll(struct file *file,
 					     poll_table *wait)
 {
 	struct cros_ec_debugfs *debug_info = file->private_data;
 	unsigned int mask = 0;

 	poll_wait(file, &debug_info->log_wq, wait);

 	mutex_lock(&debug_info->log_mutex);
 	if (CIRC_CNT(debug_info->log_buffer.head,
 		     debug_info->log_buffer.tail,
 		     LOG_SIZE))
 		mask |= POLLIN | POLLRDNORM;
 	mutex_unlock(&debug_info->log_mutex);

 	return mask;
 }

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

 const struct file_operations cros_ec_console_log_fops = {
 	.owner = THIS_MODULE,
 	.open = cros_ec_console_log_open,
 	.read = cros_ec_console_log_read,
 	.llseek = no_llseek,
 	.poll = cros_ec_console_log_poll,
 	.release = cros_ec_console_log_release,
 };

 static int ec_read_version_supported(struct cros_ec_dev *ec)
 {
 	struct ec_params_get_cmd_versions_v1 params = {
 		.cmd = EC_CMD_CONSOLE_READ,
 	};
 	struct ec_response_get_cmd_versions response;
 	struct cros_ec_command msg = {
 		.command = EC_CMD_GET_CMD_VERSIONS + ec->cmd_offset,
 		.outdata = (void *)&params,
 		.outsize = sizeof(params),
 		.indata = (void *)&response,
 		.insize = sizeof(response),
 	};
 	int ret;

 	ret = cros_ec_cmd_xfer(ec->ec_dev, &msg);
 	return ret >= 0 &&
 	       msg.result == EC_RES_SUCCESS &&
 	       (response.version_mask & EC_VER_MASK(1));
 }

 static int cros_ec_create_console_log(struct cros_ec_debugfs *debug_info)
 {
 	struct cros_ec_dev *ec = debug_info->ec;
 	char *buf;

 	if (!ec_read_version_supported(ec)) {
 		dev_warn(ec->dev,
 			"device does not support reading the console log\n");
 		return 0;
 	}

 	buf = devm_kzalloc(ec->dev, LOG_SIZE, GFP_KERNEL);
 	if (!buf)
 		return -ENOMEM;

 	debug_info->ec_buffer_size = ec->ec_dev->max_response;
 	debug_info->ec_buffer = devm_kzalloc(ec->dev,
 					debug_info->ec_buffer_size, GFP_KERNEL);
 	if (!debug_info->ec_buffer)
 		return -ENOMEM;

 	debug_info->log_buffer.buf = buf;
 	debug_info->log_buffer.head = 0;
 	debug_info->log_buffer.tail = 0;

 	mutex_init(&debug_info->log_mutex);
 	init_waitqueue_head(&debug_info->log_wq);

 	if (!debugfs_create_file("console_log",
 				 S_IFREG | S_IRUGO,
 				 debug_info->dir,
 				 debug_info,
 				 &cros_ec_console_log_fops))
 		return -ENOMEM;

 	INIT_DELAYED_WORK(&debug_info->log_poll_work,
 			  cros_ec_console_log_work);
 	schedule_delayed_work(&debug_info->log_poll_work, 0);

 	return 0;
 }

 static void cros_ec_cleanup_console_log(struct cros_ec_debugfs *debug_info)
 {
 	if (debug_info->log_buffer.buf) {
 		cancel_delayed_work_sync(&debug_info->log_poll_work);
 		mutex_destroy(&debug_info->log_mutex);
 	}
 }

 void cros_ec_debugfs_suspend(struct cros_ec_dev *ec)
 {
 	/*
 	 * cros_ec_debugfs_init() failures are non-fatal; it's also possible
 	 * that we initted things but decided that console log wasn't supported.
 	 * We'll use the same set of checks that cros_ec_debugfs_remove() +
 	 * cros_ec_cleanup_console_log() end up using to handle those cases.
 	 */
 	if (ec->debug_info && ec->debug_info->log_buffer.buf)
 		cancel_delayed_work_sync(&ec->debug_info->log_poll_work);
 }

 void cros_ec_debugfs_resume(struct cros_ec_dev *ec)
 {
 	if (ec->debug_info && ec->debug_info->log_buffer.buf)
 		schedule_delayed_work(&ec->debug_info->log_poll_work, 0);
 }

 static int cros_ec_create_panicinfo(struct cros_ec_debugfs *debug_info)
 {
 	struct cros_ec_device *ec_dev = debug_info->ec->ec_dev;
 	int ret;
 	u8 *pdata;
 	struct cros_ec_command msg = {
 		.command = EC_CMD_GET_PANIC_INFO,
 		.insize = ec_dev->max_response,
 	};

 	pdata = devm_kzalloc(debug_info->ec->dev, msg.insize, GFP_KERNEL);
 	if (!pdata)
 		return -ENOMEM;

 	msg.indata = pdata;

 	ret = cros_ec_cmd_xfer(ec_dev, &msg);
 	if (ret < 0) {
 		dev_warn(debug_info->ec->dev, "Cannot read panicinfo.\n");
 		ret = 0;
 		goto free;
 	}

 	/* No panic data */
 	if (ret == 0)
 		goto free;

 	debug_info->panicinfo_blob.data = pdata;
 	debug_info->panicinfo_blob.size = ret;

 	if (!debugfs_create_blob("panicinfo",
 				 S_IFREG | S_IRUGO,
 				 debug_info->dir,
 				 &debug_info->panicinfo_blob)) {
 		ret = -ENOMEM;
 		goto free;
 	}

 	return 0;

 free:
 	devm_kfree(debug_info->ec->dev, pdata);
 	return ret;
 }

 int cros_ec_debugfs_init(struct cros_ec_dev *ec)
 {
 	struct cros_ec_dev_platform *ec_platform = dev_get_platdata(ec->dev);
 	const char *name = ec_platform->ec_name;
 	struct cros_ec_debugfs *debug_info;
 	int ret;

 	debug_info = devm_kzalloc(ec->dev, sizeof(*debug_info), GFP_KERNEL);
 	if (!debug_info)
 		return -ENOMEM;

 	debug_info->ec = ec;
 	debug_info->dir = debugfs_create_dir(name, NULL);
 	if (!debug_info->dir)
 		return -ENOMEM;

 	ret = cros_ec_create_panicinfo(debug_info);
 	if (ret)
 		goto remove_debugfs;

 	ret = cros_ec_create_console_log(debug_info);
 	if (ret)
 		goto remove_debugfs;

 	ec->debug_info = debug_info;

 	return 0;

 remove_debugfs:
 	debugfs_remove_recursive(debug_info->dir);
 	return ret;
 }

 void cros_ec_debugfs_remove(struct cros_ec_dev *ec)
 {
 	if (!ec->debug_info)
 		return;

 	debugfs_remove_recursive(ec->debug_info->dir);
 	cros_ec_cleanup_console_log(ec->debug_info);
 }
	/*
	* cros_ec_debugfs - debug logs for Chrome OS EC
	*
	* Copyright 2015 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/circ_buf.h>
	#include <linux/debugfs.h>
	#include <linux/delay.h>
	#include <linux/fs.h>
	#include <linux/mfd/cros_ec.h>
	#include <linux/mfd/cros_ec_commands.h>
	#include <linux/mfd/cros_ec_dev.h>
	#include <linux/mutex.h>
	#include <linux/poll.h>
	#include <linux/sched.h>
	#include <linux/slab.h>
	#include <linux/wait.h>

	#include "cros_ec_debugfs.h"

	#define LOG_SHIFT 14
	#define LOG_SIZE (1 << LOG_SHIFT)
	#define LOG_POLL_SEC 10

	#define CIRC_ADD(idx, size, value) (((idx) + (value)) & ((size) - 1))

	/* struct cros_ec_debugfs - ChromeOS EC debugging information
	*
	* @ec: EC device this debugfs information belongs to
	* @dir: dentry for debugfs files
	* @log_buffer: circular buffer for console log information
	* @ec_buffer: buffer used to read console log from EC
	* @ec_buffer_size: size of that buffer
	* @log_mutex: mutex to protect circular buffer
	* @log_wq: waitqueue for log readers
	* @log_poll_work: recurring task to poll EC for new console log data
	* @panicinfo_blob: panicinfo debugfs blob
	*/
	struct cros_ec_debugfs {
	struct cros_ec_dev *ec;
	struct dentry *dir;
	/* EC log */
	struct circ_buf log_buffer;
	uint8_t *ec_buffer;
	size_t ec_buffer_size;
	struct mutex log_mutex;
	wait_queue_head_t log_wq;
	struct delayed_work log_poll_work;
	/* EC panicinfo */
	struct debugfs_blob_wrapper panicinfo_blob;
	};

	/*
	* TODO(ejcaruso): Move this from a recurring task to being triggered by
	* host events in the future. For now, this should expose a stable interface
	* for a userspace log concatenator.
	*
	* Note: We also need to make sure that the EC log on the UART is large enough,
	* so that it is unlikely enough to overlow within LOG_POLL_SEC.
	*/
	static void cros_ec_console_log_work(struct work_struct *__work)
	{
	struct cros_ec_debugfs *debug_info =
	container_of(to_delayed_work(__work),
	struct cros_ec_debugfs,
	log_poll_work);
	struct cros_ec_dev *ec = debug_info->ec;
	struct circ_buf *cb = &debug_info->log_buffer;
	struct cros_ec_command snapshot_msg = {
	.command = EC_CMD_CONSOLE_SNAPSHOT + ec->cmd_offset,
	};

	struct ec_params_console_read_v1 params = {
	.subcmd = CONSOLE_READ_RECENT,
	};

	struct cros_ec_command read_msg = {
	.version = 1,
	.command = EC_CMD_CONSOLE_READ + ec->cmd_offset,
	.outdata = (void *)&params,
	.outsize = sizeof(params),
	.indata = debug_info->ec_buffer,
	.insize = debug_info->ec_buffer_size,
	};

	int idx;
	int buf_space;
	int ret;

	ret = cros_ec_cmd_xfer(ec->ec_dev, &snapshot_msg);
	if (ret < 0) {
	dev_err(ec->dev, "EC communication failed\n");
	goto resched;
	}
	if (snapshot_msg.result != EC_RES_SUCCESS) {
	dev_err(ec->dev, "EC failed to snapshot the console log\n");
	goto resched;
	}

	/* Loop until we have read everything, or there's an error. */
	mutex_lock(&debug_info->log_mutex);
	buf_space = CIRC_SPACE(cb->head, cb->tail, LOG_SIZE);

	while (1) {
	if (!buf_space) {
	dev_info_once(ec->dev,
	"Some logs may have been dropped...\n");
	break;
	}

	memset(debug_info->ec_buffer, '\0', debug_info->ec_buffer_size);
	ret = cros_ec_cmd_xfer(ec->ec_dev, &read_msg);
	if (ret < 0) {
	dev_err(ec->dev, "EC communication failed\n");
	break;
	}
	if (read_msg.result != EC_RES_SUCCESS) {
	dev_err(ec->dev,
	"EC failed to read the console log\n");
	break;
	}

	/* If the buffer is empty, we're done here. */
	if (debug_info->ec_buffer[0] == '\0')
	break;

	idx = 0;
	while (idx < debug_info->ec_buffer_size &&
	debug_info->ec_buffer[idx] != '\0' &&
	buf_space > 0) {
	cb->buf[cb->head] = debug_info->ec_buffer[idx];
	cb->head = CIRC_ADD(cb->head, LOG_SIZE, 1);
	idx++;
	buf_space--;
	}

	wake_up(&debug_info->log_wq);
	}

	mutex_unlock(&debug_info->log_mutex);

	resched:
	schedule_delayed_work(&debug_info->log_poll_work,
	msecs_to_jiffies(LOG_POLL_SEC * 1000));
	}

	static int cros_ec_console_log_open(struct inode inode, struct file file)
	{
	file->private_data = inode->i_private;

	return nonseekable_open(inode, file);
	}

	static ssize_t cros_ec_console_log_read(struct file file, char __user buf,
	size_t count, loff_t *ppos)
	{
	struct cros_ec_debugfs *debug_info = file->private_data;
	struct circ_buf *cb = &debug_info->log_buffer;
	ssize_t ret;

	mutex_lock(&debug_info->log_mutex);

	while (!CIRC_CNT(cb->head, cb->tail, LOG_SIZE)) {
	if (file->f_flags & O_NONBLOCK) {
	ret = -EAGAIN;
	goto error;
	}

	mutex_unlock(&debug_info->log_mutex);

	ret = wait_event_interruptible(debug_info->log_wq,
	CIRC_CNT(cb->head, cb->tail, LOG_SIZE));
	if (ret < 0)
	return ret;

	mutex_lock(&debug_info->log_mutex);
	}

	/* Only copy until the end of the circular buffer, and let userspace
	* retry to get the rest of the data.
	*/
	ret = min_t(size_t, CIRC_CNT_TO_END(cb->head, cb->tail, LOG_SIZE),
	count);

	if (copy_to_user(buf, cb->buf + cb->tail, ret)) {
	ret = -EFAULT;
	goto error;
	}

	cb->tail = CIRC_ADD(cb->tail, LOG_SIZE, ret);

	error:
	mutex_unlock(&debug_info->log_mutex);
	return ret;
	}

	static unsigned int cros_ec_console_log_poll(struct file *file,
	poll_table *wait)
	{
	struct cros_ec_debugfs *debug_info = file->private_data;
	unsigned int mask = 0;

	poll_wait(file, &debug_info->log_wq, wait);

	mutex_lock(&debug_info->log_mutex);
	if (CIRC_CNT(debug_info->log_buffer.head,
	debug_info->log_buffer.tail,
	LOG_SIZE))
	mask \|= POLLIN \| POLLRDNORM;
	mutex_unlock(&debug_info->log_mutex);

	return mask;
	}

	static int cros_ec_console_log_release(struct inode inode, struct file file)
	{
	return 0;
	}

	const struct file_operations cros_ec_console_log_fops = {
	.owner = THIS_MODULE,
	.open = cros_ec_console_log_open,
	.read = cros_ec_console_log_read,
	.llseek = no_llseek,
	.poll = cros_ec_console_log_poll,
	.release = cros_ec_console_log_release,
	};

	static int ec_read_version_supported(struct cros_ec_dev *ec)
	{
	struct ec_params_get_cmd_versions_v1 params = {
	.cmd = EC_CMD_CONSOLE_READ,
	};
	struct ec_response_get_cmd_versions response;
	struct cros_ec_command msg = {
	.command = EC_CMD_GET_CMD_VERSIONS + ec->cmd_offset,
	.outdata = (void *)&params,
	.outsize = sizeof(params),
	.indata = (void *)&response,
	.insize = sizeof(response),
	};
	int ret;

	ret = cros_ec_cmd_xfer(ec->ec_dev, &msg);
	return ret >= 0 &&
	msg.result == EC_RES_SUCCESS &&
	(response.version_mask & EC_VER_MASK(1));
	}

	static int cros_ec_create_console_log(struct cros_ec_debugfs *debug_info)
	{
	struct cros_ec_dev *ec = debug_info->ec;
	char *buf;

	if (!ec_read_version_supported(ec)) {
	dev_warn(ec->dev,
	"device does not support reading the console log\n");
	return 0;
	}

	buf = devm_kzalloc(ec->dev, LOG_SIZE, GFP_KERNEL);
	if (!buf)
	return -ENOMEM;

	debug_info->ec_buffer_size = ec->ec_dev->max_response;
	debug_info->ec_buffer = devm_kzalloc(ec->dev,
	debug_info->ec_buffer_size, GFP_KERNEL);
	if (!debug_info->ec_buffer)
	return -ENOMEM;

	debug_info->log_buffer.buf = buf;
	debug_info->log_buffer.head = 0;
	debug_info->log_buffer.tail = 0;

	mutex_init(&debug_info->log_mutex);
	init_waitqueue_head(&debug_info->log_wq);

	if (!debugfs_create_file("console_log",
	S_IFREG \| S_IRUGO,
	debug_info->dir,
	debug_info,
	&cros_ec_console_log_fops))
	return -ENOMEM;

	INIT_DELAYED_WORK(&debug_info->log_poll_work,
	cros_ec_console_log_work);
	schedule_delayed_work(&debug_info->log_poll_work, 0);

	return 0;
	}

	static void cros_ec_cleanup_console_log(struct cros_ec_debugfs *debug_info)
	{
	if (debug_info->log_buffer.buf) {
	cancel_delayed_work_sync(&debug_info->log_poll_work);
	mutex_destroy(&debug_info->log_mutex);
	}
	}

	void cros_ec_debugfs_suspend(struct cros_ec_dev *ec)
	{
	/*
	* cros_ec_debugfs_init() failures are non-fatal; it's also possible
	* that we initted things but decided that console log wasn't supported.
	* We'll use the same set of checks that cros_ec_debugfs_remove() +
	* cros_ec_cleanup_console_log() end up using to handle those cases.
	*/
	if (ec->debug_info && ec->debug_info->log_buffer.buf)
	cancel_delayed_work_sync(&ec->debug_info->log_poll_work);
	}

	void cros_ec_debugfs_resume(struct cros_ec_dev *ec)
	{
	if (ec->debug_info && ec->debug_info->log_buffer.buf)
	schedule_delayed_work(&ec->debug_info->log_poll_work, 0);
	}

	static int cros_ec_create_panicinfo(struct cros_ec_debugfs *debug_info)
	{
	struct cros_ec_device *ec_dev = debug_info->ec->ec_dev;
	int ret;
	u8 *pdata;
	struct cros_ec_command msg = {
	.command = EC_CMD_GET_PANIC_INFO,
	.insize = ec_dev->max_response,
	};

	pdata = devm_kzalloc(debug_info->ec->dev, msg.insize, GFP_KERNEL);
	if (!pdata)
	return -ENOMEM;

	msg.indata = pdata;

	ret = cros_ec_cmd_xfer(ec_dev, &msg);
	if (ret < 0) {
	dev_warn(debug_info->ec->dev, "Cannot read panicinfo.\n");
	ret = 0;
	goto free;
	}

	/* No panic data */
	if (ret == 0)
	goto free;

	debug_info->panicinfo_blob.data = pdata;
	debug_info->panicinfo_blob.size = ret;

	if (!debugfs_create_blob("panicinfo",
	S_IFREG \| S_IRUGO,
	debug_info->dir,
	&debug_info->panicinfo_blob)) {
	ret = -ENOMEM;
	goto free;
	}

	return 0;

	free:
	devm_kfree(debug_info->ec->dev, pdata);
	return ret;
	}

	int cros_ec_debugfs_init(struct cros_ec_dev *ec)
	{
	struct cros_ec_dev_platform *ec_platform = dev_get_platdata(ec->dev);
	const char *name = ec_platform->ec_name;
	struct cros_ec_debugfs *debug_info;
	int ret;

	debug_info = devm_kzalloc(ec->dev, sizeof(*debug_info), GFP_KERNEL);
	if (!debug_info)
	return -ENOMEM;

	debug_info->ec = ec;
	debug_info->dir = debugfs_create_dir(name, NULL);
	if (!debug_info->dir)
	return -ENOMEM;

	ret = cros_ec_create_panicinfo(debug_info);
	if (ret)
	goto remove_debugfs;

	ret = cros_ec_create_console_log(debug_info);
	if (ret)
	goto remove_debugfs;

	ec->debug_info = debug_info;

	return 0;

	remove_debugfs:
	debugfs_remove_recursive(debug_info->dir);
	return ret;
	}

	void cros_ec_debugfs_remove(struct cros_ec_dev *ec)
	{
	if (!ec->debug_info)
	return;

	debugfs_remove_recursive(ec->debug_info->dir);
	cros_ec_cleanup_console_log(ec->debug_info);
	}