1 // SPDX-License-Identifier: GPL-2.0+
2 // Debug logs for the ChromeOS EC
4 // Copyright (C) 2015 Google, Inc.
6 #include <linux/circ_buf.h>
7 #include <linux/debugfs.h>
8 #include <linux/delay.h>
10 #include <linux/mod_devicetable.h>
11 #include <linux/module.h>
12 #include <linux/mutex.h>
13 #include <linux/platform_data/cros_ec_commands.h>
14 #include <linux/platform_data/cros_ec_proto.h>
15 #include <linux/platform_device.h>
16 #include <linux/poll.h>
17 #include <linux/sched.h>
18 #include <linux/slab.h>
19 #include <linux/wait.h>
21 #define DRV_NAME "cros-ec-debugfs"
24 #define LOG_SIZE (1 << LOG_SHIFT)
25 #define LOG_POLL_SEC 10
27 #define CIRC_ADD(idx, size, value) (((idx) + (value)) & ((size) - 1))
29 static unsigned int log_poll_period_ms = LOG_POLL_SEC * MSEC_PER_SEC;
30 module_param(log_poll_period_ms, uint, 0644);
31 MODULE_PARM_DESC(log_poll_period_ms, "EC log polling period(ms)");
33 /* waitqueue for log readers */
34 static DECLARE_WAIT_QUEUE_HEAD(cros_ec_debugfs_log_wq);
37 * struct cros_ec_debugfs - EC debugging information.
39 * @ec: EC device this debugfs information belongs to
40 * @dir: dentry for debugfs files
41 * @log_buffer: circular buffer for console log information
42 * @read_msg: preallocated EC command and buffer to read console log
43 * @log_mutex: mutex to protect circular buffer
44 * @log_poll_work: recurring task to poll EC for new console log data
45 * @panicinfo_blob: panicinfo debugfs blob
46 * @notifier_panic: notifier_block to let kernel to flush buffered log
49 struct cros_ec_debugfs {
50 struct cros_ec_dev *ec;
53 struct circ_buf log_buffer;
54 struct cros_ec_command *read_msg;
55 struct mutex log_mutex;
56 struct delayed_work log_poll_work;
58 struct debugfs_blob_wrapper panicinfo_blob;
59 struct notifier_block notifier_panic;
63 * We need to make sure that the EC log buffer on the UART is large enough,
64 * so that it is unlikely enough to overlow within log_poll_period_ms.
66 static void cros_ec_console_log_work(struct work_struct *__work)
68 struct cros_ec_debugfs *debug_info =
69 container_of(to_delayed_work(__work),
70 struct cros_ec_debugfs,
72 struct cros_ec_dev *ec = debug_info->ec;
73 struct circ_buf *cb = &debug_info->log_buffer;
74 struct cros_ec_command snapshot_msg = {
75 .command = EC_CMD_CONSOLE_SNAPSHOT + ec->cmd_offset,
78 struct ec_params_console_read_v1 *read_params =
79 (struct ec_params_console_read_v1 *)debug_info->read_msg->data;
80 uint8_t *ec_buffer = (uint8_t *)debug_info->read_msg->data;
85 ret = cros_ec_cmd_xfer_status(ec->ec_dev, &snapshot_msg);
89 /* Loop until we have read everything, or there's an error. */
90 mutex_lock(&debug_info->log_mutex);
91 buf_space = CIRC_SPACE(cb->head, cb->tail, LOG_SIZE);
95 dev_info_once(ec->dev,
96 "Some logs may have been dropped...\n");
100 memset(read_params, '\0', sizeof(*read_params));
101 read_params->subcmd = CONSOLE_READ_RECENT;
102 ret = cros_ec_cmd_xfer_status(ec->ec_dev,
103 debug_info->read_msg);
107 /* If the buffer is empty, we're done here. */
108 if (ret == 0 || ec_buffer[0] == '\0')
112 while (idx < ret && ec_buffer[idx] != '\0' && buf_space > 0) {
113 cb->buf[cb->head] = ec_buffer[idx];
114 cb->head = CIRC_ADD(cb->head, LOG_SIZE, 1);
119 wake_up(&cros_ec_debugfs_log_wq);
122 mutex_unlock(&debug_info->log_mutex);
125 schedule_delayed_work(&debug_info->log_poll_work,
126 msecs_to_jiffies(log_poll_period_ms));
129 static int cros_ec_console_log_open(struct inode *inode, struct file *file)
131 file->private_data = inode->i_private;
133 return stream_open(inode, file);
136 static ssize_t cros_ec_console_log_read(struct file *file, char __user *buf,
137 size_t count, loff_t *ppos)
139 struct cros_ec_debugfs *debug_info = file->private_data;
140 struct circ_buf *cb = &debug_info->log_buffer;
143 mutex_lock(&debug_info->log_mutex);
145 while (!CIRC_CNT(cb->head, cb->tail, LOG_SIZE)) {
146 if (file->f_flags & O_NONBLOCK) {
151 mutex_unlock(&debug_info->log_mutex);
153 ret = wait_event_interruptible(cros_ec_debugfs_log_wq,
154 CIRC_CNT(cb->head, cb->tail, LOG_SIZE));
158 mutex_lock(&debug_info->log_mutex);
161 /* Only copy until the end of the circular buffer, and let userspace
162 * retry to get the rest of the data.
164 ret = min_t(size_t, CIRC_CNT_TO_END(cb->head, cb->tail, LOG_SIZE),
167 if (copy_to_user(buf, cb->buf + cb->tail, ret)) {
172 cb->tail = CIRC_ADD(cb->tail, LOG_SIZE, ret);
175 mutex_unlock(&debug_info->log_mutex);
179 static __poll_t cros_ec_console_log_poll(struct file *file,
182 struct cros_ec_debugfs *debug_info = file->private_data;
185 poll_wait(file, &cros_ec_debugfs_log_wq, wait);
187 mutex_lock(&debug_info->log_mutex);
188 if (CIRC_CNT(debug_info->log_buffer.head,
189 debug_info->log_buffer.tail,
191 mask |= EPOLLIN | EPOLLRDNORM;
192 mutex_unlock(&debug_info->log_mutex);
197 static int cros_ec_console_log_release(struct inode *inode, struct file *file)
202 static ssize_t cros_ec_pdinfo_read(struct file *file,
203 char __user *user_buf,
207 char read_buf[EC_USB_PD_MAX_PORTS * 40], *p = read_buf;
208 struct cros_ec_debugfs *debug_info = file->private_data;
209 struct cros_ec_device *ec_dev = debug_info->ec->ec_dev;
211 struct cros_ec_command msg;
213 struct ec_response_usb_pd_control_v1 resp;
214 struct ec_params_usb_pd_control params;
217 struct cros_ec_command *msg;
218 struct ec_response_usb_pd_control_v1 *resp;
219 struct ec_params_usb_pd_control *params;
223 params = (struct ec_params_usb_pd_control *)msg->data;
224 resp = (struct ec_response_usb_pd_control_v1 *)msg->data;
226 msg->command = EC_CMD_USB_PD_CONTROL;
228 msg->insize = sizeof(*resp);
229 msg->outsize = sizeof(*params);
232 * Read status from all PD ports until failure, typically caused
233 * by attempting to read status on a port that doesn't exist.
235 for (i = 0; i < EC_USB_PD_MAX_PORTS; ++i) {
241 if (cros_ec_cmd_xfer_status(ec_dev, msg) < 0)
244 p += scnprintf(p, sizeof(read_buf) + read_buf - p,
245 "p%d: %s en:%.2x role:%.2x pol:%.2x\n", i,
246 resp->state, resp->enabled, resp->role,
250 return simple_read_from_buffer(user_buf, count, ppos,
251 read_buf, p - read_buf);
254 static bool cros_ec_uptime_is_supported(struct cros_ec_device *ec_dev)
257 struct cros_ec_command cmd;
258 struct ec_response_uptime_info resp;
262 msg.cmd.command = EC_CMD_GET_UPTIME_INFO;
263 msg.cmd.insize = sizeof(msg.resp);
265 ret = cros_ec_cmd_xfer_status(ec_dev, &msg.cmd);
266 if (ret == -EPROTO && msg.cmd.result == EC_RES_INVALID_COMMAND)
269 /* Other errors maybe a transient error, do not rule about support. */
273 static ssize_t cros_ec_uptime_read(struct file *file, char __user *user_buf,
274 size_t count, loff_t *ppos)
276 struct cros_ec_debugfs *debug_info = file->private_data;
277 struct cros_ec_device *ec_dev = debug_info->ec->ec_dev;
279 struct cros_ec_command cmd;
280 struct ec_response_uptime_info resp;
282 struct ec_response_uptime_info *resp;
286 resp = (struct ec_response_uptime_info *)&msg.resp;
288 msg.cmd.command = EC_CMD_GET_UPTIME_INFO;
289 msg.cmd.insize = sizeof(*resp);
291 ret = cros_ec_cmd_xfer_status(ec_dev, &msg.cmd);
295 ret = scnprintf(read_buf, sizeof(read_buf), "%u\n",
296 resp->time_since_ec_boot_ms);
298 return simple_read_from_buffer(user_buf, count, ppos, read_buf, ret);
301 static const struct file_operations cros_ec_console_log_fops = {
302 .owner = THIS_MODULE,
303 .open = cros_ec_console_log_open,
304 .read = cros_ec_console_log_read,
306 .poll = cros_ec_console_log_poll,
307 .release = cros_ec_console_log_release,
310 static const struct file_operations cros_ec_pdinfo_fops = {
311 .owner = THIS_MODULE,
313 .read = cros_ec_pdinfo_read,
314 .llseek = default_llseek,
317 static const struct file_operations cros_ec_uptime_fops = {
318 .owner = THIS_MODULE,
320 .read = cros_ec_uptime_read,
321 .llseek = default_llseek,
324 static int ec_read_version_supported(struct cros_ec_dev *ec)
326 struct ec_params_get_cmd_versions_v1 *params;
327 struct ec_response_get_cmd_versions *response;
330 struct cros_ec_command *msg;
332 msg = kzalloc(sizeof(*msg) + max(sizeof(*params), sizeof(*response)),
338 msg->command = EC_CMD_GET_CMD_VERSIONS + ec->cmd_offset;
339 msg->outsize = sizeof(*params);
340 msg->insize = sizeof(*response);
342 params = (struct ec_params_get_cmd_versions_v1 *)msg->data;
343 params->cmd = EC_CMD_CONSOLE_READ;
344 response = (struct ec_response_get_cmd_versions *)msg->data;
346 ret = cros_ec_cmd_xfer_status(ec->ec_dev, msg) >= 0 &&
347 response->version_mask & EC_VER_MASK(1);
354 static int cros_ec_create_console_log(struct cros_ec_debugfs *debug_info)
356 struct cros_ec_dev *ec = debug_info->ec;
358 int read_params_size;
359 int read_response_size;
362 * If the console log feature is not supported return silently and
363 * don't create the console_log entry.
365 if (!ec_read_version_supported(ec))
368 buf = devm_kzalloc(ec->dev, LOG_SIZE, GFP_KERNEL);
372 read_params_size = sizeof(struct ec_params_console_read_v1);
373 read_response_size = ec->ec_dev->max_response;
374 debug_info->read_msg = devm_kzalloc(ec->dev,
375 sizeof(*debug_info->read_msg) +
376 max(read_params_size, read_response_size), GFP_KERNEL);
377 if (!debug_info->read_msg)
380 debug_info->read_msg->version = 1;
381 debug_info->read_msg->command = EC_CMD_CONSOLE_READ + ec->cmd_offset;
382 debug_info->read_msg->outsize = read_params_size;
383 debug_info->read_msg->insize = read_response_size;
385 debug_info->log_buffer.buf = buf;
386 debug_info->log_buffer.head = 0;
387 debug_info->log_buffer.tail = 0;
389 mutex_init(&debug_info->log_mutex);
391 debugfs_create_file("console_log", S_IFREG | 0444, debug_info->dir,
392 debug_info, &cros_ec_console_log_fops);
394 INIT_DELAYED_WORK(&debug_info->log_poll_work,
395 cros_ec_console_log_work);
396 schedule_delayed_work(&debug_info->log_poll_work, 0);
401 static void cros_ec_cleanup_console_log(struct cros_ec_debugfs *debug_info)
403 if (debug_info->log_buffer.buf) {
404 cancel_delayed_work_sync(&debug_info->log_poll_work);
405 mutex_destroy(&debug_info->log_mutex);
410 * Returns the size of the panicinfo data fetched from the EC
412 static int cros_ec_get_panicinfo(struct cros_ec_device *ec_dev, uint8_t *data,
416 struct cros_ec_command *msg;
418 if (!data || data_size <= 0 || data_size > ec_dev->max_response)
421 msg = kzalloc(sizeof(*msg) + data_size, GFP_KERNEL);
425 msg->command = EC_CMD_GET_PANIC_INFO;
426 msg->insize = data_size;
428 ret = cros_ec_cmd_xfer_status(ec_dev, msg);
432 memcpy(data, msg->data, data_size);
439 static int cros_ec_create_panicinfo(struct cros_ec_debugfs *debug_info)
441 struct cros_ec_device *ec_dev = debug_info->ec->ec_dev;
445 data = devm_kzalloc(debug_info->ec->dev, ec_dev->max_response,
450 ret = cros_ec_get_panicinfo(ec_dev, data, ec_dev->max_response);
460 debug_info->panicinfo_blob.data = data;
461 debug_info->panicinfo_blob.size = ret;
463 debugfs_create_blob("panicinfo", 0444, debug_info->dir,
464 &debug_info->panicinfo_blob);
469 devm_kfree(debug_info->ec->dev, data);
473 static int cros_ec_debugfs_panic_event(struct notifier_block *nb,
474 unsigned long queued_during_suspend, void *_notify)
476 struct cros_ec_debugfs *debug_info =
477 container_of(nb, struct cros_ec_debugfs, notifier_panic);
479 if (debug_info->log_buffer.buf) {
480 /* Force log poll work to run immediately */
481 mod_delayed_work(debug_info->log_poll_work.wq, &debug_info->log_poll_work, 0);
482 /* Block until log poll work finishes */
483 flush_delayed_work(&debug_info->log_poll_work);
489 static int cros_ec_debugfs_probe(struct platform_device *pd)
491 struct cros_ec_dev *ec = dev_get_drvdata(pd->dev.parent);
492 struct cros_ec_platform *ec_platform = dev_get_platdata(ec->dev);
493 const char *name = ec_platform->ec_name;
494 struct cros_ec_debugfs *debug_info;
497 debug_info = devm_kzalloc(ec->dev, sizeof(*debug_info), GFP_KERNEL);
502 debug_info->dir = debugfs_create_dir(name, NULL);
504 ret = cros_ec_create_panicinfo(debug_info);
508 ret = cros_ec_create_console_log(debug_info);
512 debugfs_create_file("pdinfo", 0444, debug_info->dir, debug_info,
513 &cros_ec_pdinfo_fops);
515 if (cros_ec_uptime_is_supported(ec->ec_dev))
516 debugfs_create_file("uptime", 0444, debug_info->dir, debug_info,
517 &cros_ec_uptime_fops);
519 debugfs_create_x32("last_resume_result", 0444, debug_info->dir,
520 &ec->ec_dev->last_resume_result);
522 debugfs_create_u16("suspend_timeout_ms", 0664, debug_info->dir,
523 &ec->ec_dev->suspend_timeout_ms);
525 debug_info->notifier_panic.notifier_call = cros_ec_debugfs_panic_event;
526 ret = blocking_notifier_chain_register(&ec->ec_dev->panic_notifier,
527 &debug_info->notifier_panic);
531 ec->debug_info = debug_info;
533 dev_set_drvdata(&pd->dev, ec);
538 debugfs_remove_recursive(debug_info->dir);
542 static void cros_ec_debugfs_remove(struct platform_device *pd)
544 struct cros_ec_dev *ec = dev_get_drvdata(pd->dev.parent);
546 debugfs_remove_recursive(ec->debug_info->dir);
547 cros_ec_cleanup_console_log(ec->debug_info);
550 static int __maybe_unused cros_ec_debugfs_suspend(struct device *dev)
552 struct cros_ec_dev *ec = dev_get_drvdata(dev);
554 if (ec->debug_info->log_buffer.buf)
555 cancel_delayed_work_sync(&ec->debug_info->log_poll_work);
560 static int __maybe_unused cros_ec_debugfs_resume(struct device *dev)
562 struct cros_ec_dev *ec = dev_get_drvdata(dev);
564 if (ec->debug_info->log_buffer.buf)
565 schedule_delayed_work(&ec->debug_info->log_poll_work, 0);
570 static SIMPLE_DEV_PM_OPS(cros_ec_debugfs_pm_ops,
571 cros_ec_debugfs_suspend, cros_ec_debugfs_resume);
573 static const struct platform_device_id cros_ec_debugfs_id[] = {
577 MODULE_DEVICE_TABLE(platform, cros_ec_debugfs_id);
579 static struct platform_driver cros_ec_debugfs_driver = {
582 .pm = &cros_ec_debugfs_pm_ops,
583 .probe_type = PROBE_PREFER_ASYNCHRONOUS,
585 .probe = cros_ec_debugfs_probe,
586 .remove_new = cros_ec_debugfs_remove,
587 .id_table = cros_ec_debugfs_id,
590 module_platform_driver(cros_ec_debugfs_driver);
592 MODULE_LICENSE("GPL");
593 MODULE_DESCRIPTION("Debug logs for ChromeOS EC");