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/pci.h>
21 #include <linux/sched.h>
22 #include <linux/watchdog.h>
24 #include <linux/mei.h>
30 static const u8 mei_start_wd_params[] = { 0x02, 0x12, 0x13, 0x10 };
31 static const u8 mei_stop_wd_params[] = { 0x02, 0x02, 0x14, 0x10 };
36 #define INTEL_AMT_WATCHDOG_ID "INTCAMT"
38 /* UUIDs for AMT F/W clients */
39 const uuid_le mei_wd_guid = UUID_LE(0x05B79A6F, 0x4628, 0x4D7F, 0x89,
40 0x9D, 0xA9, 0x15, 0x14, 0xCB,
43 static void mei_wd_set_start_timeout(struct mei_device *dev, u16 timeout)
45 dev_dbg(&dev->pdev->dev, "wd: set timeout=%d.\n", timeout);
46 memcpy(dev->wd_data, mei_start_wd_params, MEI_WD_HDR_SIZE);
47 memcpy(dev->wd_data + MEI_WD_HDR_SIZE, &timeout, sizeof(u16));
51 * mei_wd_host_init - connect to the watchdog client
53 * @dev: the device structure
55 * returns -ENOTTY if wd client cannot be found
56 * -EIO if write has failed
59 int mei_wd_host_init(struct mei_device *dev)
61 struct mei_cl *cl = &dev->wd_cl;
62 struct mei_me_client *me_cl;
67 dev->wd_timeout = MEI_WD_DEFAULT_TIMEOUT;
68 dev->wd_state = MEI_WD_IDLE;
71 /* check for valid client id */
72 me_cl = mei_me_cl_by_uuid(dev, &mei_wd_guid);
74 dev_info(&dev->pdev->dev, "wd: failed to find the client\n");
78 cl->me_client_id = me_cl->client_id;
80 ret = mei_cl_link(cl, MEI_WD_HOST_CLIENT_ID);
83 dev_info(&dev->pdev->dev, "wd: failed link client\n");
87 ret = mei_cl_connect(cl, NULL);
90 dev_err(&dev->pdev->dev, "wd: failed to connect = %d\n", ret);
95 ret = mei_watchdog_register(dev);
97 mei_cl_disconnect(cl);
104 * mei_wd_send - sends watch dog message to fw.
106 * @dev: the device structure
108 * returns 0 if success,
109 * -EIO when message send fails
110 * -EINVAL when invalid message is to be sent
111 * -ENODEV on flow control failure
113 int mei_wd_send(struct mei_device *dev)
115 struct mei_cl *cl = &dev->wd_cl;
116 struct mei_msg_hdr hdr;
119 hdr.host_addr = cl->host_client_id;
120 hdr.me_addr = cl->me_client_id;
121 hdr.msg_complete = 1;
125 if (!memcmp(dev->wd_data, mei_start_wd_params, MEI_WD_HDR_SIZE))
126 hdr.length = MEI_WD_START_MSG_SIZE;
127 else if (!memcmp(dev->wd_data, mei_stop_wd_params, MEI_WD_HDR_SIZE))
128 hdr.length = MEI_WD_STOP_MSG_SIZE;
130 dev_err(&dev->pdev->dev, "wd: invalid message is to be sent, aborting\n");
134 ret = mei_write_message(dev, &hdr, dev->wd_data);
136 dev_err(&dev->pdev->dev, "wd: write message failed\n");
140 ret = mei_cl_flow_ctrl_reduce(cl);
142 dev_err(&dev->pdev->dev, "wd: flow_ctrl_reduce failed.\n");
150 * mei_wd_stop - sends watchdog stop message to fw.
152 * @dev: the device structure
153 * @preserve: indicate if to keep the timeout value
155 * returns 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->pdev->dev,
196 "wd: stop failed to complete ret=%d.\n", ret);
199 dev_dbg(&dev->pdev->dev, "wd: stop completed after %u msec\n",
200 MEI_WD_STOP_TIMEOUT - jiffies_to_msecs(ret));
207 * mei_wd_ops_start - wd start command from the watchdog core.
209 * @wd_dev - watchdog device struct
211 * returns 0 if success, negative errno code for failure
213 static int mei_wd_ops_start(struct watchdog_device *wd_dev)
216 struct mei_device *dev;
218 dev = watchdog_get_drvdata(wd_dev);
222 mutex_lock(&dev->device_lock);
224 if (dev->dev_state != MEI_DEV_ENABLED) {
225 dev_dbg(&dev->pdev->dev,
226 "wd: dev_state != MEI_DEV_ENABLED dev_state = %s\n",
227 mei_dev_state_str(dev->dev_state));
231 if (dev->wd_cl.state != MEI_FILE_CONNECTED) {
232 dev_dbg(&dev->pdev->dev,
233 "MEI Driver is not connected to Watchdog Client\n");
237 mei_wd_set_start_timeout(dev, dev->wd_timeout);
241 mutex_unlock(&dev->device_lock);
246 * mei_wd_ops_stop - wd stop command from the watchdog core.
248 * @wd_dev - watchdog device struct
250 * returns 0 if success, negative errno code for failure
252 static int mei_wd_ops_stop(struct watchdog_device *wd_dev)
254 struct mei_device *dev;
256 dev = watchdog_get_drvdata(wd_dev);
260 mutex_lock(&dev->device_lock);
262 mutex_unlock(&dev->device_lock);
268 * mei_wd_ops_ping - wd ping command from the watchdog core.
270 * @wd_dev - watchdog device struct
272 * returns 0 if success, negative errno code for failure
274 static int mei_wd_ops_ping(struct watchdog_device *wd_dev)
276 struct mei_device *dev;
279 dev = watchdog_get_drvdata(wd_dev);
283 mutex_lock(&dev->device_lock);
285 if (dev->wd_cl.state != MEI_FILE_CONNECTED) {
286 dev_err(&dev->pdev->dev, "wd: not connected.\n");
291 dev->wd_state = MEI_WD_RUNNING;
293 ret = mei_cl_flow_ctrl_creds(&dev->wd_cl);
296 /* Check if we can send the ping to HW*/
297 if (ret && mei_hbuf_acquire(dev)) {
299 dev_dbg(&dev->pdev->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 * returns 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->pdev->dev, "wd: unable to register watchdog device = %d.\n",
387 dev_dbg(&dev->pdev->dev,
388 "wd: successfully register watchdog interface.\n");
389 watchdog_set_drvdata(&amt_wd_dev, dev);
393 void mei_watchdog_unregister(struct mei_device *dev)
395 if (watchdog_get_drvdata(&amt_wd_dev) == NULL)
398 watchdog_set_drvdata(&amt_wd_dev, NULL);
399 watchdog_unregister_device(&amt_wd_dev);