[deliverable/linux.git] / drivers / misc / mei / init.c

/*
 *
 * Intel Management Engine Interface (Intel MEI) Linux driver
 * Copyright (c) 2003-2012, Intel Corporation.
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms and conditions of the GNU General Public License,
 * version 2, as published by the Free Software Foundation.
 *
 * This program is distributed in the hope 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.
 *
 */

#include <linux/export.h>
#include <linux/sched.h>
#include <linux/wait.h>
#include <linux/delay.h>

#include <linux/mei.h>

#include "mei_dev.h"
#include "hbm.h"
#include "client.h"

const char *mei_dev_state_str(int state)
{
#define MEI_DEV_STATE(state) case MEI_DEV_##state: return #state
	switch (state) {
	MEI_DEV_STATE(INITIALIZING);
	MEI_DEV_STATE(INIT_CLIENTS);
	MEI_DEV_STATE(ENABLED);
	MEI_DEV_STATE(RESETTING);
	MEI_DEV_STATE(DISABLED);
	MEI_DEV_STATE(POWER_DOWN);
	MEI_DEV_STATE(POWER_UP);
	default:
		return "unknown";
	}
#undef MEI_DEV_STATE
}

const char *mei_pg_state_str(enum mei_pg_state state)
{
#define MEI_PG_STATE(state) case MEI_PG_##state: return #state
	switch (state) {
	MEI_PG_STATE(OFF);
	MEI_PG_STATE(ON);
	default:
		return "unknown";
	}
#undef MEI_PG_STATE
}

/**
 * mei_fw_status2str - convert fw status registers to printable string
 *
 * @fw_status:  firmware status
 * @buf: string buffer at minimal size MEI_FW_STATUS_STR_SZ
 * @len: buffer len must be >= MEI_FW_STATUS_STR_SZ
 *
 * Return: number of bytes written or -EINVAL if buffer is to small
 */
ssize_t mei_fw_status2str(struct mei_fw_status *fw_status,
			  char *buf, size_t len)
{
	ssize_t cnt = 0;
	int i;

	buf[0] = '\0';

	if (len < MEI_FW_STATUS_STR_SZ)
		return -EINVAL;

	for (i = 0; i < fw_status->count; i++)
		cnt += scnprintf(buf + cnt, len - cnt, "%08X ",
				fw_status->status[i]);

	/* drop last space */
	buf[cnt] = '\0';
	return cnt;
}
EXPORT_SYMBOL_GPL(mei_fw_status2str);

/**
 * mei_cancel_work - Cancel mei background jobs
 *
 * @dev: the device structure
 */
void mei_cancel_work(struct mei_device *dev)
{
	cancel_work_sync(&dev->init_work);
	cancel_work_sync(&dev->reset_work);

	cancel_delayed_work(&dev->timer_work);
}
EXPORT_SYMBOL_GPL(mei_cancel_work);

/**
 * mei_reset - resets host and fw.
 *
 * @dev: the device structure
 *
 * Return: 0 on success or < 0 if the reset hasn't succeeded
 */
int mei_reset(struct mei_device *dev)
{
	enum mei_dev_state state = dev->dev_state;
	bool interrupts_enabled;
	int ret;

	if (state != MEI_DEV_INITIALIZING &&
	    state != MEI_DEV_DISABLED &&
	    state != MEI_DEV_POWER_DOWN &&
	    state != MEI_DEV_POWER_UP) {
		char fw_sts_str[MEI_FW_STATUS_STR_SZ];

		mei_fw_status_str(dev, fw_sts_str, MEI_FW_STATUS_STR_SZ);
		dev_warn(dev->dev, "unexpected reset: dev_state = %s fw status = %s\n",
			 mei_dev_state_str(state), fw_sts_str);
	}

	/* we're already in reset, cancel the init timer
	 * if the reset was called due the hbm protocol error
	 * we need to call it before hw start
	 * so the hbm watchdog won't kick in
	 */
	mei_hbm_idle(dev);

	/* enter reset flow */
	interrupts_enabled = state != MEI_DEV_POWER_DOWN;
	dev->dev_state = MEI_DEV_RESETTING;

	dev->reset_count++;
	if (dev->reset_count > MEI_MAX_CONSEC_RESET) {
		dev_err(dev->dev, "reset: reached maximal consecutive resets: disabling the device\n");
		dev->dev_state = MEI_DEV_DISABLED;
		return -ENODEV;
	}

	ret = mei_hw_reset(dev, interrupts_enabled);
	/* fall through and remove the sw state even if hw reset has failed */

	/* no need to clean up software state in case of power up */
	if (state != MEI_DEV_INITIALIZING &&
	    state != MEI_DEV_POWER_UP) {

		/* remove all waiting requests */
		mei_cl_all_write_clear(dev);

		mei_cl_all_disconnect(dev);

		/* wake up all readers and writers so they can be interrupted */
		mei_cl_all_wakeup(dev);

		/* remove entry if already in list */
		dev_dbg(dev->dev, "remove iamthif and wd from the file list.\n");
		mei_cl_unlink(&dev->wd_cl);
		mei_cl_unlink(&dev->iamthif_cl);
		mei_amthif_reset_params(dev);
	}

	mei_hbm_reset(dev);

	dev->rd_msg_hdr = 0;
	dev->wd_pending = false;

	if (ret) {
		dev_err(dev->dev, "hw_reset failed ret = %d\n", ret);
		return ret;
	}

	if (state == MEI_DEV_POWER_DOWN) {
		dev_dbg(dev->dev, "powering down: end of reset\n");
		dev->dev_state = MEI_DEV_DISABLED;
		return 0;
	}

	ret = mei_hw_start(dev);
	if (ret) {
		dev_err(dev->dev, "hw_start failed ret = %d\n", ret);
		return ret;
	}

	dev_dbg(dev->dev, "link is established start sending messages.\n");

	dev->dev_state = MEI_DEV_INIT_CLIENTS;
	ret = mei_hbm_start_req(dev);
	if (ret) {
		dev_err(dev->dev, "hbm_start failed ret = %d\n", ret);
		dev->dev_state = MEI_DEV_RESETTING;
		return ret;
	}

	return 0;
}
EXPORT_SYMBOL_GPL(mei_reset);

/**
 * mei_start - initializes host and fw to start work.
 *
 * @dev: the device structure
 *
 * Return: 0 on success, <0 on failure.
 */
int mei_start(struct mei_device *dev)
{
	int ret;

	mutex_lock(&dev->device_lock);

	/* acknowledge interrupt and stop interrupts */
	mei_clear_interrupts(dev);

	mei_hw_config(dev);

	dev_dbg(dev->dev, "reset in start the mei device.\n");

	dev->reset_count = 0;
	do {
		dev->dev_state = MEI_DEV_INITIALIZING;
		ret = mei_reset(dev);

		if (ret == -ENODEV || dev->dev_state == MEI_DEV_DISABLED) {
			dev_err(dev->dev, "reset failed ret = %d", ret);
			goto err;
		}
	} while (ret);

	/* we cannot start the device w/o hbm start message completed */
	if (dev->dev_state == MEI_DEV_DISABLED) {
		dev_err(dev->dev, "reset failed");
		goto err;
	}

	if (mei_hbm_start_wait(dev)) {
		dev_err(dev->dev, "HBM haven't started");
		goto err;
	}

	if (!mei_host_is_ready(dev)) {
		dev_err(dev->dev, "host is not ready.\n");
		goto err;
	}

	if (!mei_hw_is_ready(dev)) {
		dev_err(dev->dev, "ME is not ready.\n");
		goto err;
	}

	if (!mei_hbm_version_is_supported(dev)) {
		dev_dbg(dev->dev, "MEI start failed.\n");
		goto err;
	}

	dev_dbg(dev->dev, "link layer has been established.\n");

	mutex_unlock(&dev->device_lock);
	return 0;
err:
	dev_err(dev->dev, "link layer initialization failed.\n");
	dev->dev_state = MEI_DEV_DISABLED;
	mutex_unlock(&dev->device_lock);
	return -ENODEV;
}
EXPORT_SYMBOL_GPL(mei_start);

/**
 * mei_restart - restart device after suspend
 *
 * @dev: the device structure
 *
 * Return: 0 on success or -ENODEV if the restart hasn't succeeded
 */
int mei_restart(struct mei_device *dev)
{
	int err;

	mutex_lock(&dev->device_lock);

	mei_clear_interrupts(dev);

	dev->dev_state = MEI_DEV_POWER_UP;
	dev->reset_count = 0;

	err = mei_reset(dev);

	mutex_unlock(&dev->device_lock);

	if (err == -ENODEV || dev->dev_state == MEI_DEV_DISABLED) {
		dev_err(dev->dev, "device disabled = %d\n", err);
		return -ENODEV;
	}

	/* try to start again */
	if (err)
		schedule_work(&dev->reset_work);


	return 0;
}
EXPORT_SYMBOL_GPL(mei_restart);

static void mei_reset_work(struct work_struct *work)
{
	struct mei_device *dev =
		container_of(work, struct mei_device,  reset_work);
	int ret;

	mutex_lock(&dev->device_lock);

	ret = mei_reset(dev);

	mutex_unlock(&dev->device_lock);

	if (dev->dev_state == MEI_DEV_DISABLED) {
		dev_err(dev->dev, "device disabled = %d\n", ret);
		return;
	}

	/* retry reset in case of failure */
	if (ret)
		schedule_work(&dev->reset_work);
}

void mei_stop(struct mei_device *dev)
{
	dev_dbg(dev->dev, "stopping the device.\n");

	mei_cancel_work(dev);

	mei_cl_bus_remove_devices(dev);

	mutex_lock(&dev->device_lock);

	mei_wd_stop(dev);

	dev->dev_state = MEI_DEV_POWER_DOWN;
	mei_reset(dev);
	/* move device to disabled state unconditionally */
	dev->dev_state = MEI_DEV_DISABLED;

	mutex_unlock(&dev->device_lock);

	mei_watchdog_unregister(dev);
}
EXPORT_SYMBOL_GPL(mei_stop);

/**
 * mei_write_is_idle - check if the write queues are idle
 *
 * @dev: the device structure
 *
 * Return: true of there is no pending write
 */
bool mei_write_is_idle(struct mei_device *dev)
{
	bool idle = (dev->dev_state == MEI_DEV_ENABLED &&
		list_empty(&dev->ctrl_wr_list.list) &&
		list_empty(&dev->write_list.list)   &&
		list_empty(&dev->write_waiting_list.list));

	dev_dbg(dev->dev, "write pg: is idle[%d] state=%s ctrl=%01d write=%01d wwait=%01d\n",
		idle,
		mei_dev_state_str(dev->dev_state),
		list_empty(&dev->ctrl_wr_list.list),
		list_empty(&dev->write_list.list),
		list_empty(&dev->write_waiting_list.list));

	return idle;
}
EXPORT_SYMBOL_GPL(mei_write_is_idle);

/**
 * mei_device_init  -- initialize mei_device structure
 *
 * @dev: the mei device
 * @device: the device structure
 * @hw_ops: hw operations
 */
void mei_device_init(struct mei_device *dev,
		     struct device *device,
		     const struct mei_hw_ops *hw_ops)
{
	/* setup our list array */
	INIT_LIST_HEAD(&dev->file_list);
	INIT_LIST_HEAD(&dev->device_list);
	INIT_LIST_HEAD(&dev->me_clients);
	mutex_init(&dev->device_lock);
	init_rwsem(&dev->me_clients_rwsem);
	mutex_init(&dev->cl_bus_lock);
	init_waitqueue_head(&dev->wait_hw_ready);
	init_waitqueue_head(&dev->wait_pg);
	init_waitqueue_head(&dev->wait_hbm_start);
	init_waitqueue_head(&dev->wait_stop_wd);
	dev->dev_state = MEI_DEV_INITIALIZING;
	dev->reset_count = 0;

	mei_io_list_init(&dev->write_list);
	mei_io_list_init(&dev->write_waiting_list);
	mei_io_list_init(&dev->ctrl_wr_list);
	mei_io_list_init(&dev->ctrl_rd_list);

	INIT_DELAYED_WORK(&dev->timer_work, mei_timer);
	INIT_WORK(&dev->init_work, mei_host_client_init);
	INIT_WORK(&dev->reset_work, mei_reset_work);

	INIT_LIST_HEAD(&dev->wd_cl.link);
	INIT_LIST_HEAD(&dev->iamthif_cl.link);
	mei_io_list_init(&dev->amthif_cmd_list);
	mei_io_list_init(&dev->amthif_rd_complete_list);

	bitmap_zero(dev->host_clients_map, MEI_CLIENTS_MAX);
	dev->open_handle_count = 0;

	/*
	 * Reserving the first client ID
	 * 0: Reserved for MEI Bus Message communications
	 */
	bitmap_set(dev->host_clients_map, 0, 1);

	dev->pg_event = MEI_PG_EVENT_IDLE;
	dev->ops      = hw_ops;
	dev->dev      = device;
}
EXPORT_SYMBOL_GPL(mei_device_init);
Commit	Line	Data
91f01c6d OW	1	/*
	2	*
	3	* Intel Management Engine Interface (Intel MEI) Linux driver
733ba91c	4	* Copyright (c) 2003-2012, Intel Corporation.
91f01c6d OW	5	*
	6	* This program is free software; you can redistribute it and/or modify it
	7	* under the terms and conditions of the GNU General Public License,
	8	* version 2, as published by the Free Software Foundation.
	9	*
	10	* This program is distributed in the hope it will be useful, but WITHOUT
	11	* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
	12	* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
	13	* more details.
	14	*
	15	*/
	16
40e0b67b	17	#include <linux/export.h>
91f01c6d OW	18	#include <linux/sched.h>
	19	#include <linux/wait.h>
	20	#include <linux/delay.h>
	21
47a73801 TW	22	#include <linux/mei.h>
47a73801 TW	23
91f01c6d	24	#include "mei_dev.h"
aafae7ec	25	#include "hbm.h"
90e0b5f1	26	#include "client.h"
91f01c6d	27
b210d750 TW	28	const char *mei_dev_state_str(int state)
	29	{
	30	#define MEI_DEV_STATE(state) case MEI_DEV_##state: return #state
	31	switch (state) {
	32	MEI_DEV_STATE(INITIALIZING);
	33	MEI_DEV_STATE(INIT_CLIENTS);
	34	MEI_DEV_STATE(ENABLED);
0cfee51c	35	MEI_DEV_STATE(RESETTING);
b210d750	36	MEI_DEV_STATE(DISABLED);
b210d750 TW	37	MEI_DEV_STATE(POWER_DOWN);
	38	MEI_DEV_STATE(POWER_UP);
	39	default:
8b513d0c	40	return "unknown";
b210d750 TW	41	}
	42	#undef MEI_DEV_STATE
	43	}
	44
1beeb4b9 AU	45	const char *mei_pg_state_str(enum mei_pg_state state)
	46	{
	47	#define MEI_PG_STATE(state) case MEI_PG_##state: return #state
	48	switch (state) {
	49	MEI_PG_STATE(OFF);
	50	MEI_PG_STATE(ON);
	51	default:
	52	return "unknown";
	53	}
	54	#undef MEI_PG_STATE
	55	}
	56
edca5ea3 AU	57	/**
	58	* mei_fw_status2str - convert fw status registers to printable string
	59	*
	60	* @fw_status: firmware status
	61	* @buf: string buffer at minimal size MEI_FW_STATUS_STR_SZ
	62	* @len: buffer len must be >= MEI_FW_STATUS_STR_SZ
	63	*
	64	* Return: number of bytes written or -EINVAL if buffer is to small
	65	*/
	66	ssize_t mei_fw_status2str(struct mei_fw_status *fw_status,
	67	char *buf, size_t len)
	68	{
	69	ssize_t cnt = 0;
	70	int i;
	71
	72	buf[0] = '\0';
	73
	74	if (len < MEI_FW_STATUS_STR_SZ)
	75	return -EINVAL;
	76
	77	for (i = 0; i < fw_status->count; i++)
	78	cnt += scnprintf(buf + cnt, len - cnt, "%08X ",
	79	fw_status->status[i]);
	80
	81	/* drop last space */
	82	buf[cnt] = '\0';
	83	return cnt;
	84	}
	85	EXPORT_SYMBOL_GPL(mei_fw_status2str);
91f01c6d	86
544f9460	87	/**
a8605ea2	88	* mei_cancel_work - Cancel mei background jobs
544f9460 TW	89	*
	90	* @dev: the device structure
	91	*/
dc844b0d TW	92	void mei_cancel_work(struct mei_device *dev)
	93	{
	94	cancel_work_sync(&dev->init_work);
544f9460	95	cancel_work_sync(&dev->reset_work);
dc844b0d TW	96
	97	cancel_delayed_work(&dev->timer_work);
	98	}
	99	EXPORT_SYMBOL_GPL(mei_cancel_work);
	100
91f01c6d OW	101	/**
	102	* mei_reset - resets host and fw.
	103	*
	104	* @dev: the device structure
ce23139c AU	105	*
ce23139c AU	106	* Return: 0 on success or < 0 if the reset hasn't succeeded
91f01c6d	107	*/
33ec0826	108	int mei_reset(struct mei_device *dev)
91f01c6d	109	{
33ec0826 TW	110	enum mei_dev_state state = dev->dev_state;
33ec0826 TW	111	bool interrupts_enabled;
c20c68d5	112	int ret;
91f01c6d	113
33ec0826 TW	114	if (state != MEI_DEV_INITIALIZING &&
	115	state != MEI_DEV_DISABLED &&
	116	state != MEI_DEV_POWER_DOWN &&
04dd3661	117	state != MEI_DEV_POWER_UP) {
edca5ea3	118	char fw_sts_str[MEI_FW_STATUS_STR_SZ];
92db1555	119
edca5ea3 AU	120	mei_fw_status_str(dev, fw_sts_str, MEI_FW_STATUS_STR_SZ);
	121	dev_warn(dev->dev, "unexpected reset: dev_state = %s fw status = %s\n",
	122	mei_dev_state_str(state), fw_sts_str);
04dd3661	123	}
f931f4f3	124
66ae460b TW	125	/* we're already in reset, cancel the init timer
	126	* if the reset was called due the hbm protocol error
	127	* we need to call it before hw start
	128	* so the hbm watchdog won't kick in
	129	*/
	130	mei_hbm_idle(dev);
	131
33ec0826 TW	132	/* enter reset flow */
	133	interrupts_enabled = state != MEI_DEV_POWER_DOWN;
	134	dev->dev_state = MEI_DEV_RESETTING;
91f01c6d	135
6adb8efb TW	136	dev->reset_count++;
6adb8efb TW	137	if (dev->reset_count > MEI_MAX_CONSEC_RESET) {
2bf94cab	138	dev_err(dev->dev, "reset: reached maximal consecutive resets: disabling the device\n");
6adb8efb TW	139	dev->dev_state = MEI_DEV_DISABLED;
	140	return -ENODEV;
	141	}
	142
33ec0826 TW	143	ret = mei_hw_reset(dev, interrupts_enabled);
33ec0826 TW	144	/* fall through and remove the sw state even if hw reset has failed */
91f01c6d	145
33ec0826 TW	146	/* no need to clean up software state in case of power up */
	147	if (state != MEI_DEV_INITIALIZING &&
	148	state != MEI_DEV_POWER_UP) {
91f01c6d	149
b950ac1d TW	150	/* remove all waiting requests */
	151	mei_cl_all_write_clear(dev);
	152
074b4c01 TW	153	mei_cl_all_disconnect(dev);
074b4c01 TW	154
33ec0826	155	/* wake up all readers and writers so they can be interrupted */
b950ac1d TW	156	mei_cl_all_wakeup(dev);
b950ac1d TW	157
91f01c6d	158	/* remove entry if already in list */
2bf94cab	159	dev_dbg(dev->dev, "remove iamthif and wd from the file list.\n");
90e0b5f1 TW	160	mei_cl_unlink(&dev->wd_cl);
90e0b5f1 TW	161	mei_cl_unlink(&dev->iamthif_cl);
19838fb8	162	mei_amthif_reset_params(dev);
91f01c6d OW	163	}
91f01c6d OW	164
84b3294a	165	mei_hbm_reset(dev);
4a704575	166
91f01c6d	167	dev->rd_msg_hdr = 0;
eb9af0ac	168	dev->wd_pending = false;
91f01c6d	169
33ec0826	170	if (ret) {
2bf94cab	171	dev_err(dev->dev, "hw_reset failed ret = %d\n", ret);
33ec0826 TW	172	return ret;
	173	}
	174
	175	if (state == MEI_DEV_POWER_DOWN) {
2bf94cab	176	dev_dbg(dev->dev, "powering down: end of reset\n");
33ec0826 TW	177	dev->dev_state = MEI_DEV_DISABLED;
33ec0826 TW	178	return 0;
aafae7ec TW	179	}
aafae7ec TW	180
9049f793 TW	181	ret = mei_hw_start(dev);
9049f793 TW	182	if (ret) {
2bf94cab	183	dev_err(dev->dev, "hw_start failed ret = %d\n", ret);
33ec0826	184	return ret;
9049f793	185	}
aafae7ec	186
2bf94cab	187	dev_dbg(dev->dev, "link is established start sending messages.\n");
aafae7ec TW	188
aafae7ec TW	189	dev->dev_state = MEI_DEV_INIT_CLIENTS;
544f9460 TW	190	ret = mei_hbm_start_req(dev);
544f9460 TW	191	if (ret) {
2bf94cab	192	dev_err(dev->dev, "hbm_start failed ret = %d\n", ret);
7d93e58d	193	dev->dev_state = MEI_DEV_RESETTING;
33ec0826	194	return ret;
544f9460	195	}
33ec0826 TW	196
33ec0826 TW	197	return 0;
91f01c6d	198	}
40e0b67b	199	EXPORT_SYMBOL_GPL(mei_reset);
91f01c6d	200
33ec0826 TW	201	/**
	202	* mei_start - initializes host and fw to start work.
	203	*
	204	* @dev: the device structure
	205	*
a8605ea2	206	* Return: 0 on success, <0 on failure.
33ec0826 TW	207	*/
	208	int mei_start(struct mei_device *dev)
	209	{
7d93e58d	210	int ret;
92db1555	211
33ec0826 TW	212	mutex_lock(&dev->device_lock);
	213
	214	/* acknowledge interrupt and stop interrupts */
	215	mei_clear_interrupts(dev);
	216
	217	mei_hw_config(dev);
	218
2bf94cab	219	dev_dbg(dev->dev, "reset in start the mei device.\n");
33ec0826	220
6adb8efb	221	dev->reset_count = 0;
7d93e58d TW	222	do {
	223	dev->dev_state = MEI_DEV_INITIALIZING;
	224	ret = mei_reset(dev);
	225
	226	if (ret == -ENODEV \|\| dev->dev_state == MEI_DEV_DISABLED) {
2bf94cab	227	dev_err(dev->dev, "reset failed ret = %d", ret);
7d93e58d TW	228	goto err;
	229	}
	230	} while (ret);
33ec0826	231
7d93e58d	232	/* we cannot start the device w/o hbm start message completed */
33ec0826	233	if (dev->dev_state == MEI_DEV_DISABLED) {
2bf94cab	234	dev_err(dev->dev, "reset failed");
33ec0826 TW	235	goto err;
	236	}
	237
	238	if (mei_hbm_start_wait(dev)) {
2bf94cab	239	dev_err(dev->dev, "HBM haven't started");
33ec0826 TW	240	goto err;
	241	}
	242
	243	if (!mei_host_is_ready(dev)) {
2bf94cab	244	dev_err(dev->dev, "host is not ready.\n");
33ec0826 TW	245	goto err;
	246	}
	247
	248	if (!mei_hw_is_ready(dev)) {
2bf94cab	249	dev_err(dev->dev, "ME is not ready.\n");
33ec0826 TW	250	goto err;
	251	}
	252
	253	if (!mei_hbm_version_is_supported(dev)) {
2bf94cab	254	dev_dbg(dev->dev, "MEI start failed.\n");
33ec0826 TW	255	goto err;
	256	}
	257
2bf94cab	258	dev_dbg(dev->dev, "link layer has been established.\n");
33ec0826 TW	259
	260	mutex_unlock(&dev->device_lock);
	261	return 0;
	262	err:
2bf94cab	263	dev_err(dev->dev, "link layer initialization failed.\n");
33ec0826 TW	264	dev->dev_state = MEI_DEV_DISABLED;
	265	mutex_unlock(&dev->device_lock);
	266	return -ENODEV;
	267	}
	268	EXPORT_SYMBOL_GPL(mei_start);
	269
	270	/**
	271	* mei_restart - restart device after suspend
	272	*
	273	* @dev: the device structure
	274	*
a8605ea2	275	* Return: 0 on success or -ENODEV if the restart hasn't succeeded
33ec0826 TW	276	*/
	277	int mei_restart(struct mei_device *dev)
	278	{
	279	int err;
	280
	281	mutex_lock(&dev->device_lock);
	282
	283	mei_clear_interrupts(dev);
	284
	285	dev->dev_state = MEI_DEV_POWER_UP;
6adb8efb	286	dev->reset_count = 0;
33ec0826 TW	287
	288	err = mei_reset(dev);
	289
	290	mutex_unlock(&dev->device_lock);
	291
7d93e58d	292	if (err == -ENODEV \|\| dev->dev_state == MEI_DEV_DISABLED) {
2bf94cab	293	dev_err(dev->dev, "device disabled = %d\n", err);
33ec0826	294	return -ENODEV;
7d93e58d TW	295	}
	296
	297	/* try to start again */
	298	if (err)
	299	schedule_work(&dev->reset_work);
	300
33ec0826 TW	301
	302	return 0;
	303	}
	304	EXPORT_SYMBOL_GPL(mei_restart);
	305
544f9460 TW	306	static void mei_reset_work(struct work_struct *work)
	307	{
	308	struct mei_device *dev =
	309	container_of(work, struct mei_device, reset_work);
7d93e58d	310	int ret;
544f9460 TW	311
	312	mutex_lock(&dev->device_lock);
	313
7d93e58d	314	ret = mei_reset(dev);
544f9460 TW	315
544f9460 TW	316	mutex_unlock(&dev->device_lock);
33ec0826	317
7d93e58d	318	if (dev->dev_state == MEI_DEV_DISABLED) {
2bf94cab	319	dev_err(dev->dev, "device disabled = %d\n", ret);
7d93e58d TW	320	return;
	321	}
	322
	323	/* retry reset in case of failure */
	324	if (ret)
	325	schedule_work(&dev->reset_work);
544f9460 TW	326	}
544f9460 TW	327
7cb035d9 TW	328	void mei_stop(struct mei_device *dev)
7cb035d9 TW	329	{
2bf94cab	330	dev_dbg(dev->dev, "stopping the device.\n");
7cb035d9	331
dc844b0d	332	mei_cancel_work(dev);
5e85b364	333
6009595a	334	mei_cl_bus_remove_devices(dev);
7cb035d9	335
dc844b0d	336	mutex_lock(&dev->device_lock);
7cb035d9 TW	337
	338	mei_wd_stop(dev);
	339
	340	dev->dev_state = MEI_DEV_POWER_DOWN;
33ec0826	341	mei_reset(dev);
6c15a851 AU	342	/* move device to disabled state unconditionally */
6c15a851 AU	343	dev->dev_state = MEI_DEV_DISABLED;
7cb035d9 TW	344
	345	mutex_unlock(&dev->device_lock);
	346
2e647124	347	mei_watchdog_unregister(dev);
7cb035d9	348	}
40e0b67b	349	EXPORT_SYMBOL_GPL(mei_stop);
91f01c6d	350
a532bbed TW	351	/**
	352	* mei_write_is_idle - check if the write queues are idle
	353	*
	354	* @dev: the device structure
	355	*
a8605ea2	356	* Return: true of there is no pending write
a532bbed TW	357	*/
	358	bool mei_write_is_idle(struct mei_device *dev)
	359	{
	360	bool idle = (dev->dev_state == MEI_DEV_ENABLED &&
	361	list_empty(&dev->ctrl_wr_list.list) &&
41c95b04 TW	362	list_empty(&dev->write_list.list) &&
41c95b04 TW	363	list_empty(&dev->write_waiting_list.list));
c1174c0e	364
41c95b04	365	dev_dbg(dev->dev, "write pg: is idle[%d] state=%s ctrl=%01d write=%01d wwait=%01d\n",
a532bbed TW	366	idle,
	367	mei_dev_state_str(dev->dev_state),
	368	list_empty(&dev->ctrl_wr_list.list),
41c95b04 TW	369	list_empty(&dev->write_list.list),
41c95b04 TW	370	list_empty(&dev->write_waiting_list.list));
a532bbed TW	371
	372	return idle;
	373	}
	374	EXPORT_SYMBOL_GPL(mei_write_is_idle);
91f01c6d	375
3a7e9b6c TW	376	/**
	377	* mei_device_init -- initialize mei_device structure
	378	*
	379	* @dev: the mei device
	380	* @device: the device structure
	381	* @hw_ops: hw operations
	382	*/
	383	void mei_device_init(struct mei_device *dev,
	384	struct device *device,
	385	const struct mei_hw_ops *hw_ops)
544f9460 TW	386	{
	387	/* setup our list array */
	388	INIT_LIST_HEAD(&dev->file_list);
	389	INIT_LIST_HEAD(&dev->device_list);
5ca2d388	390	INIT_LIST_HEAD(&dev->me_clients);
544f9460	391	mutex_init(&dev->device_lock);
b7d88514	392	init_rwsem(&dev->me_clients_rwsem);
0ff0a8d8	393	mutex_init(&dev->cl_bus_lock);
544f9460	394	init_waitqueue_head(&dev->wait_hw_ready);
4fcbc99b	395	init_waitqueue_head(&dev->wait_pg);
cb02efc3	396	init_waitqueue_head(&dev->wait_hbm_start);
544f9460 TW	397	init_waitqueue_head(&dev->wait_stop_wd);
544f9460 TW	398	dev->dev_state = MEI_DEV_INITIALIZING;
6adb8efb	399	dev->reset_count = 0;
544f9460	400
544f9460 TW	401	mei_io_list_init(&dev->write_list);
	402	mei_io_list_init(&dev->write_waiting_list);
	403	mei_io_list_init(&dev->ctrl_wr_list);
	404	mei_io_list_init(&dev->ctrl_rd_list);
	405
	406	INIT_DELAYED_WORK(&dev->timer_work, mei_timer);
	407	INIT_WORK(&dev->init_work, mei_host_client_init);
	408	INIT_WORK(&dev->reset_work, mei_reset_work);
	409
	410	INIT_LIST_HEAD(&dev->wd_cl.link);
	411	INIT_LIST_HEAD(&dev->iamthif_cl.link);
	412	mei_io_list_init(&dev->amthif_cmd_list);
	413	mei_io_list_init(&dev->amthif_rd_complete_list);
	414
	415	bitmap_zero(dev->host_clients_map, MEI_CLIENTS_MAX);
	416	dev->open_handle_count = 0;
	417
	418	/*
	419	* Reserving the first client ID
	420	* 0: Reserved for MEI Bus Message communications
	421	*/
	422	bitmap_set(dev->host_clients_map, 0, 1);
964a2331 TW	423
964a2331 TW	424	dev->pg_event = MEI_PG_EVENT_IDLE;
3a7e9b6c TW	425	dev->ops = hw_ops;
3a7e9b6c TW	426	dev->dev = device;
544f9460 TW	427	}
	428	EXPORT_SYMBOL_GPL(mei_device_init);
	429