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
17 #include <linux/export.h>
18 #include <linux/pci.h>
19 #include <linux/sched.h>
20 #include <linux/wait.h>
21 #include <linux/delay.h>
23 #include <linux/mei.h>
29 const char *mei_dev_state_str(int state)
31 #define MEI_DEV_STATE(state) case MEI_DEV_##state: return #state
33 MEI_DEV_STATE(INITIALIZING);
34 MEI_DEV_STATE(INIT_CLIENTS);
35 MEI_DEV_STATE(ENABLED);
36 MEI_DEV_STATE(RESETTING);
37 MEI_DEV_STATE(DISABLED);
38 MEI_DEV_STATE(POWER_DOWN);
39 MEI_DEV_STATE(POWER_UP);
48 * mei_cancel_work. Cancel mei background jobs
50 * @dev: the device structure
52 * returns 0 on success or < 0 if the reset hasn't succeeded
54 void mei_cancel_work(struct mei_device *dev)
56 cancel_work_sync(&dev->init_work);
57 cancel_work_sync(&dev->reset_work);
59 cancel_delayed_work(&dev->timer_work);
61 EXPORT_SYMBOL_GPL(mei_cancel_work);
64 * mei_reset - resets host and fw.
66 * @dev: the device structure
68 int mei_reset(struct mei_device *dev)
70 enum mei_dev_state state = dev->dev_state;
71 bool interrupts_enabled;
74 if (state != MEI_DEV_INITIALIZING &&
75 state != MEI_DEV_DISABLED &&
76 state != MEI_DEV_POWER_DOWN &&
77 state != MEI_DEV_POWER_UP)
78 dev_warn(&dev->pdev->dev, "unexpected reset: dev_state = %s\n",
79 mei_dev_state_str(state));
81 /* we're already in reset, cancel the init timer
82 * if the reset was called due the hbm protocol error
83 * we need to call it before hw start
84 * so the hbm watchdog won't kick in
88 /* enter reset flow */
89 interrupts_enabled = state != MEI_DEV_POWER_DOWN;
90 dev->dev_state = MEI_DEV_RESETTING;
93 if (dev->reset_count > MEI_MAX_CONSEC_RESET) {
94 dev_err(&dev->pdev->dev, "reset: reached maximal consecutive resets: disabling the device\n");
95 dev->dev_state = MEI_DEV_DISABLED;
99 ret = mei_hw_reset(dev, interrupts_enabled);
100 /* fall through and remove the sw state even if hw reset has failed */
102 /* no need to clean up software state in case of power up */
103 if (state != MEI_DEV_INITIALIZING &&
104 state != MEI_DEV_POWER_UP) {
106 /* remove all waiting requests */
107 mei_cl_all_write_clear(dev);
109 mei_cl_all_disconnect(dev);
111 /* wake up all readers and writers so they can be interrupted */
112 mei_cl_all_wakeup(dev);
114 /* remove entry if already in list */
115 dev_dbg(&dev->pdev->dev, "remove iamthif and wd from the file list.\n");
116 mei_cl_unlink(&dev->wd_cl);
117 mei_cl_unlink(&dev->iamthif_cl);
118 mei_amthif_reset_params(dev);
119 memset(&dev->wr_ext_msg, 0, sizeof(dev->wr_ext_msg));
123 dev->me_clients_num = 0;
125 dev->wd_pending = false;
128 dev_err(&dev->pdev->dev, "hw_reset failed ret = %d\n", ret);
132 if (state == MEI_DEV_POWER_DOWN) {
133 dev_dbg(&dev->pdev->dev, "powering down: end of reset\n");
134 dev->dev_state = MEI_DEV_DISABLED;
138 ret = mei_hw_start(dev);
140 dev_err(&dev->pdev->dev, "hw_start failed ret = %d\n", ret);
144 dev_dbg(&dev->pdev->dev, "link is established start sending messages.\n");
146 dev->dev_state = MEI_DEV_INIT_CLIENTS;
147 ret = mei_hbm_start_req(dev);
149 dev_err(&dev->pdev->dev, "hbm_start failed ret = %d\n", ret);
150 dev->dev_state = MEI_DEV_RESETTING;
156 EXPORT_SYMBOL_GPL(mei_reset);
159 * mei_start - initializes host and fw to start work.
161 * @dev: the device structure
163 * returns 0 on success, <0 on failure.
165 int mei_start(struct mei_device *dev)
168 mutex_lock(&dev->device_lock);
170 /* acknowledge interrupt and stop interrupts */
171 mei_clear_interrupts(dev);
175 dev_dbg(&dev->pdev->dev, "reset in start the mei device.\n");
177 dev->reset_count = 0;
179 dev->dev_state = MEI_DEV_INITIALIZING;
180 ret = mei_reset(dev);
182 if (ret == -ENODEV || dev->dev_state == MEI_DEV_DISABLED) {
183 dev_err(&dev->pdev->dev, "reset failed ret = %d", ret);
188 /* we cannot start the device w/o hbm start message completed */
189 if (dev->dev_state == MEI_DEV_DISABLED) {
190 dev_err(&dev->pdev->dev, "reset failed");
194 if (mei_hbm_start_wait(dev)) {
195 dev_err(&dev->pdev->dev, "HBM haven't started");
199 if (!mei_host_is_ready(dev)) {
200 dev_err(&dev->pdev->dev, "host is not ready.\n");
204 if (!mei_hw_is_ready(dev)) {
205 dev_err(&dev->pdev->dev, "ME is not ready.\n");
209 if (!mei_hbm_version_is_supported(dev)) {
210 dev_dbg(&dev->pdev->dev, "MEI start failed.\n");
214 dev_dbg(&dev->pdev->dev, "link layer has been established.\n");
216 mutex_unlock(&dev->device_lock);
219 dev_err(&dev->pdev->dev, "link layer initialization failed.\n");
220 dev->dev_state = MEI_DEV_DISABLED;
221 mutex_unlock(&dev->device_lock);
224 EXPORT_SYMBOL_GPL(mei_start);
227 * mei_restart - restart device after suspend
229 * @dev: the device structure
231 * returns 0 on success or -ENODEV if the restart hasn't succeeded
233 int mei_restart(struct mei_device *dev)
237 mutex_lock(&dev->device_lock);
239 mei_clear_interrupts(dev);
241 dev->dev_state = MEI_DEV_POWER_UP;
242 dev->reset_count = 0;
244 err = mei_reset(dev);
246 mutex_unlock(&dev->device_lock);
248 if (err == -ENODEV || dev->dev_state == MEI_DEV_DISABLED) {
249 dev_err(&dev->pdev->dev, "device disabled = %d\n", err);
253 /* try to start again */
255 schedule_work(&dev->reset_work);
260 EXPORT_SYMBOL_GPL(mei_restart);
262 static void mei_reset_work(struct work_struct *work)
264 struct mei_device *dev =
265 container_of(work, struct mei_device, reset_work);
268 mutex_lock(&dev->device_lock);
270 ret = mei_reset(dev);
272 mutex_unlock(&dev->device_lock);
274 if (dev->dev_state == MEI_DEV_DISABLED) {
275 dev_err(&dev->pdev->dev, "device disabled = %d\n", ret);
279 /* retry reset in case of failure */
281 schedule_work(&dev->reset_work);
284 void mei_stop(struct mei_device *dev)
286 dev_dbg(&dev->pdev->dev, "stopping the device.\n");
288 mei_cancel_work(dev);
290 mei_nfc_host_exit(dev);
292 mutex_lock(&dev->device_lock);
296 dev->dev_state = MEI_DEV_POWER_DOWN;
299 mutex_unlock(&dev->device_lock);
301 mei_watchdog_unregister(dev);
303 EXPORT_SYMBOL_GPL(mei_stop);
307 void mei_device_init(struct mei_device *dev)
309 /* setup our list array */
310 INIT_LIST_HEAD(&dev->file_list);
311 INIT_LIST_HEAD(&dev->device_list);
312 mutex_init(&dev->device_lock);
313 init_waitqueue_head(&dev->wait_hw_ready);
314 init_waitqueue_head(&dev->wait_recvd_msg);
315 init_waitqueue_head(&dev->wait_stop_wd);
316 dev->dev_state = MEI_DEV_INITIALIZING;
317 dev->reset_count = 0;
319 mei_io_list_init(&dev->read_list);
320 mei_io_list_init(&dev->write_list);
321 mei_io_list_init(&dev->write_waiting_list);
322 mei_io_list_init(&dev->ctrl_wr_list);
323 mei_io_list_init(&dev->ctrl_rd_list);
325 INIT_DELAYED_WORK(&dev->timer_work, mei_timer);
326 INIT_WORK(&dev->init_work, mei_host_client_init);
327 INIT_WORK(&dev->reset_work, mei_reset_work);
329 INIT_LIST_HEAD(&dev->wd_cl.link);
330 INIT_LIST_HEAD(&dev->iamthif_cl.link);
331 mei_io_list_init(&dev->amthif_cmd_list);
332 mei_io_list_init(&dev->amthif_rd_complete_list);
334 bitmap_zero(dev->host_clients_map, MEI_CLIENTS_MAX);
335 dev->open_handle_count = 0;
338 * Reserving the first client ID
339 * 0: Reserved for MEI Bus Message communications
341 bitmap_set(dev->host_clients_map, 0, 1);
343 EXPORT_SYMBOL_GPL(mei_device_init);