3 * Intel Management Engine Interface (Intel MEI) Linux driver
4 * Copyright (c) 2003-2012, Intel Corporation.
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.
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
16 #include <linux/kernel.h>
17 #include <linux/module.h>
18 #include <linux/moduleparam.h>
19 #include <linux/device.h>
20 #include <linux/sched.h>
21 #include <linux/watchdog.h>
23 #include <linux/mei.h>
29 static const u8 mei_start_wd_params[] = { 0x02, 0x12, 0x13, 0x10 };
30 static const u8 mei_stop_wd_params[] = { 0x02, 0x02, 0x14, 0x10 };
35 #define INTEL_AMT_WATCHDOG_ID "INTCAMT"
37 /* UUIDs for AMT F/W clients */
38 const uuid_le mei_wd_guid = UUID_LE(0x05B79A6F, 0x4628, 0x4D7F, 0x89,
39 0x9D, 0xA9, 0x15, 0x14, 0xCB,
42 static void mei_wd_set_start_timeout(struct mei_device *dev, u16 timeout)
44 dev_dbg(dev->dev, "wd: set timeout=%d.\n", timeout);
45 memcpy(dev->wd_data, mei_start_wd_params, MEI_WD_HDR_SIZE);
46 memcpy(dev->wd_data + MEI_WD_HDR_SIZE, &timeout, sizeof(u16));
50 * mei_wd_host_init - connect to the watchdog client
52 * @dev: the device structure
54 * Return: -ENOTTY if wd client cannot be found
55 * -EIO if write has failed
58 int mei_wd_host_init(struct mei_device *dev)
60 struct mei_cl *cl = &dev->wd_cl;
61 struct mei_me_client *me_cl;
66 dev->wd_timeout = MEI_WD_DEFAULT_TIMEOUT;
67 dev->wd_state = MEI_WD_IDLE;
70 /* check for valid client id */
71 me_cl = mei_me_cl_by_uuid(dev, &mei_wd_guid);
73 dev_info(dev->dev, "wd: failed to find the client\n");
77 cl->me_client_id = me_cl->client_id;
78 cl->cl_uuid = me_cl->props.protocol_name;
81 ret = mei_cl_link(cl, MEI_WD_HOST_CLIENT_ID);
84 dev_info(dev->dev, "wd: failed link client\n");
88 ret = mei_cl_connect(cl, NULL);
91 dev_err(dev->dev, "wd: failed to connect = %d\n", ret);
96 ret = mei_watchdog_register(dev);
98 mei_cl_disconnect(cl);
105 * mei_wd_send - sends watch dog message to fw.
107 * @dev: the device structure
109 * Return: 0 if success,
110 * -EIO when message send fails
111 * -EINVAL when invalid message is to be sent
112 * -ENODEV on flow control failure
114 int mei_wd_send(struct mei_device *dev)
116 struct mei_cl *cl = &dev->wd_cl;
117 struct mei_msg_hdr hdr;
120 hdr.host_addr = cl->host_client_id;
121 hdr.me_addr = cl->me_client_id;
122 hdr.msg_complete = 1;
126 if (!memcmp(dev->wd_data, mei_start_wd_params, MEI_WD_HDR_SIZE))
127 hdr.length = MEI_WD_START_MSG_SIZE;
128 else if (!memcmp(dev->wd_data, mei_stop_wd_params, MEI_WD_HDR_SIZE))
129 hdr.length = MEI_WD_STOP_MSG_SIZE;
131 dev_err(dev->dev, "wd: invalid message is to be sent, aborting\n");
135 ret = mei_write_message(dev, &hdr, dev->wd_data);
137 dev_err(dev->dev, "wd: write message failed\n");
141 ret = mei_cl_flow_ctrl_reduce(cl);
143 dev_err(dev->dev, "wd: flow_ctrl_reduce failed.\n");
151 * mei_wd_stop - sends watchdog stop message to fw.
153 * @dev: the device structure
155 * Return: 0 if success
157 * -EIO when message send fails
158 * -EINVAL when invalid message is to be sent
159 * -ETIME on message timeout
161 int mei_wd_stop(struct mei_device *dev)
165 if (dev->wd_cl.state != MEI_FILE_CONNECTED ||
166 dev->wd_state != MEI_WD_RUNNING)
169 memcpy(dev->wd_data, mei_stop_wd_params, MEI_WD_STOP_MSG_SIZE);
171 dev->wd_state = MEI_WD_STOPPING;
173 ret = mei_cl_flow_ctrl_creds(&dev->wd_cl);
177 if (ret && mei_hbuf_acquire(dev)) {
178 ret = mei_wd_send(dev);
181 dev->wd_pending = false;
183 dev->wd_pending = true;
186 mutex_unlock(&dev->device_lock);
188 ret = wait_event_timeout(dev->wait_stop_wd,
189 dev->wd_state == MEI_WD_IDLE,
190 msecs_to_jiffies(MEI_WD_STOP_TIMEOUT));
191 mutex_lock(&dev->device_lock);
192 if (dev->wd_state != MEI_WD_IDLE) {
195 dev_warn(dev->dev, "wd: stop failed to complete ret=%d\n", ret);
198 dev_dbg(dev->dev, "wd: stop completed after %u msec\n",
199 MEI_WD_STOP_TIMEOUT - jiffies_to_msecs(ret));
206 * mei_wd_ops_start - wd start command from the watchdog core.
208 * @wd_dev - watchdog device struct
210 * Return: 0 if success, negative errno code for failure
212 static int mei_wd_ops_start(struct watchdog_device *wd_dev)
215 struct mei_device *dev;
217 dev = watchdog_get_drvdata(wd_dev);
221 mutex_lock(&dev->device_lock);
223 if (dev->dev_state != MEI_DEV_ENABLED) {
224 dev_dbg(dev->dev, "wd: dev_state != MEI_DEV_ENABLED dev_state = %s\n",
225 mei_dev_state_str(dev->dev_state));
229 if (dev->wd_cl.state != MEI_FILE_CONNECTED) {
230 dev_dbg(dev->dev, "MEI Driver is not connected to Watchdog Client\n");
234 mei_wd_set_start_timeout(dev, dev->wd_timeout);
238 mutex_unlock(&dev->device_lock);
243 * mei_wd_ops_stop - wd stop command from the watchdog core.
245 * @wd_dev - watchdog device struct
247 * Return: 0 if success, negative errno code for failure
249 static int mei_wd_ops_stop(struct watchdog_device *wd_dev)
251 struct mei_device *dev;
253 dev = watchdog_get_drvdata(wd_dev);
257 mutex_lock(&dev->device_lock);
259 mutex_unlock(&dev->device_lock);
265 * mei_wd_ops_ping - wd ping command from the watchdog core.
267 * @wd_dev - watchdog device struct
269 * Return: 0 if success, negative errno code for failure
271 static int mei_wd_ops_ping(struct watchdog_device *wd_dev)
273 struct mei_device *dev;
277 dev = watchdog_get_drvdata(wd_dev);
283 mutex_lock(&dev->device_lock);
285 if (cl->state != MEI_FILE_CONNECTED) {
286 dev_err(dev->dev, "wd: not connected.\n");
291 dev->wd_state = MEI_WD_RUNNING;
293 ret = mei_cl_flow_ctrl_creds(cl);
297 /* Check if we can send the ping to HW*/
298 if (ret && mei_hbuf_acquire(dev)) {
299 dev_dbg(dev->dev, "wd: sending ping\n");
301 ret = mei_wd_send(dev);
304 dev->wd_pending = false;
306 dev->wd_pending = true;
310 mutex_unlock(&dev->device_lock);
315 * mei_wd_ops_set_timeout - wd set timeout command from the watchdog core.
317 * @wd_dev - watchdog device struct
318 * @timeout - timeout value to set
320 * Return: 0 if success, negative errno code for failure
322 static int mei_wd_ops_set_timeout(struct watchdog_device *wd_dev,
323 unsigned int timeout)
325 struct mei_device *dev;
327 dev = watchdog_get_drvdata(wd_dev);
331 /* Check Timeout value */
332 if (timeout < MEI_WD_MIN_TIMEOUT || timeout > MEI_WD_MAX_TIMEOUT)
335 mutex_lock(&dev->device_lock);
337 dev->wd_timeout = timeout;
338 wd_dev->timeout = timeout;
339 mei_wd_set_start_timeout(dev, dev->wd_timeout);
341 mutex_unlock(&dev->device_lock);
347 * Watchdog Device structs
349 static const struct watchdog_ops wd_ops = {
350 .owner = THIS_MODULE,
351 .start = mei_wd_ops_start,
352 .stop = mei_wd_ops_stop,
353 .ping = mei_wd_ops_ping,
354 .set_timeout = mei_wd_ops_set_timeout,
356 static const struct watchdog_info wd_info = {
357 .identity = INTEL_AMT_WATCHDOG_ID,
358 .options = WDIOF_KEEPALIVEPING |
363 static struct watchdog_device amt_wd_dev = {
366 .timeout = MEI_WD_DEFAULT_TIMEOUT,
367 .min_timeout = MEI_WD_MIN_TIMEOUT,
368 .max_timeout = MEI_WD_MAX_TIMEOUT,
372 int mei_watchdog_register(struct mei_device *dev)
377 /* unlock to perserve correct locking order */
378 mutex_unlock(&dev->device_lock);
379 ret = watchdog_register_device(&amt_wd_dev);
380 mutex_lock(&dev->device_lock);
382 dev_err(dev->dev, "wd: unable to register watchdog device = %d.\n",
387 dev_dbg(dev->dev, "wd: successfully register watchdog interface.\n");
388 watchdog_set_drvdata(&amt_wd_dev, dev);
392 void mei_watchdog_unregister(struct mei_device *dev)
394 if (watchdog_get_drvdata(&amt_wd_dev) == NULL)
397 watchdog_set_drvdata(&amt_wd_dev, NULL);
398 watchdog_unregister_device(&amt_wd_dev);