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/mfd/cros_ec.h>
11 #include <linux/mfd/cros_ec_commands.h>
12 #include <linux/module.h>
13 #include <linux/mutex.h>
14 #include <linux/platform_device.h>
15 #include <linux/poll.h>
16 #include <linux/sched.h>
17 #include <linux/slab.h>
18 #include <linux/wait.h>
20 #define DRV_NAME "cros-ec-debugfs"
23 #define LOG_SIZE (1 << LOG_SHIFT)
24 #define LOG_POLL_SEC 10
26 #define CIRC_ADD(idx, size, value) (((idx) + (value)) & ((size) - 1))
29 * struct cros_ec_debugfs - EC debugging information.
31 * @ec: EC device this debugfs information belongs to
32 * @dir: dentry for debugfs files
33 * @log_buffer: circular buffer for console log information
34 * @read_msg: preallocated EC command and buffer to read console log
35 * @log_mutex: mutex to protect circular buffer
36 * @log_wq: waitqueue for log readers
37 * @log_poll_work: recurring task to poll EC for new console log data
38 * @panicinfo_blob: panicinfo debugfs blob
40 struct cros_ec_debugfs {
41 struct cros_ec_dev *ec;
44 struct circ_buf log_buffer;
45 struct cros_ec_command *read_msg;
46 struct mutex log_mutex;
47 wait_queue_head_t log_wq;
48 struct delayed_work log_poll_work;
50 struct debugfs_blob_wrapper panicinfo_blob;
54 * We need to make sure that the EC log buffer on the UART is large enough,
55 * so that it is unlikely enough to overlow within LOG_POLL_SEC.
57 static void cros_ec_console_log_work(struct work_struct *__work)
59 struct cros_ec_debugfs *debug_info =
60 container_of(to_delayed_work(__work),
61 struct cros_ec_debugfs,
63 struct cros_ec_dev *ec = debug_info->ec;
64 struct circ_buf *cb = &debug_info->log_buffer;
65 struct cros_ec_command snapshot_msg = {
66 .command = EC_CMD_CONSOLE_SNAPSHOT + ec->cmd_offset,
69 struct ec_params_console_read_v1 *read_params =
70 (struct ec_params_console_read_v1 *)debug_info->read_msg->data;
71 uint8_t *ec_buffer = (uint8_t *)debug_info->read_msg->data;
76 ret = cros_ec_cmd_xfer_status(ec->ec_dev, &snapshot_msg);
80 /* Loop until we have read everything, or there's an error. */
81 mutex_lock(&debug_info->log_mutex);
82 buf_space = CIRC_SPACE(cb->head, cb->tail, LOG_SIZE);
86 dev_info_once(ec->dev,
87 "Some logs may have been dropped...\n");
91 memset(read_params, '\0', sizeof(*read_params));
92 read_params->subcmd = CONSOLE_READ_RECENT;
93 ret = cros_ec_cmd_xfer_status(ec->ec_dev,
94 debug_info->read_msg);
98 /* If the buffer is empty, we're done here. */
99 if (ret == 0 || ec_buffer[0] == '\0')
103 while (idx < ret && ec_buffer[idx] != '\0' && buf_space > 0) {
104 cb->buf[cb->head] = ec_buffer[idx];
105 cb->head = CIRC_ADD(cb->head, LOG_SIZE, 1);
110 wake_up(&debug_info->log_wq);
113 mutex_unlock(&debug_info->log_mutex);
116 schedule_delayed_work(&debug_info->log_poll_work,
117 msecs_to_jiffies(LOG_POLL_SEC * 1000));
120 static int cros_ec_console_log_open(struct inode *inode, struct file *file)
122 file->private_data = inode->i_private;
124 return stream_open(inode, file);
127 static ssize_t cros_ec_console_log_read(struct file *file, char __user *buf,
128 size_t count, loff_t *ppos)
130 struct cros_ec_debugfs *debug_info = file->private_data;
131 struct circ_buf *cb = &debug_info->log_buffer;
134 mutex_lock(&debug_info->log_mutex);
136 while (!CIRC_CNT(cb->head, cb->tail, LOG_SIZE)) {
137 if (file->f_flags & O_NONBLOCK) {
142 mutex_unlock(&debug_info->log_mutex);
144 ret = wait_event_interruptible(debug_info->log_wq,
145 CIRC_CNT(cb->head, cb->tail, LOG_SIZE));
149 mutex_lock(&debug_info->log_mutex);
152 /* Only copy until the end of the circular buffer, and let userspace
153 * retry to get the rest of the data.
155 ret = min_t(size_t, CIRC_CNT_TO_END(cb->head, cb->tail, LOG_SIZE),
158 if (copy_to_user(buf, cb->buf + cb->tail, ret)) {
163 cb->tail = CIRC_ADD(cb->tail, LOG_SIZE, ret);
166 mutex_unlock(&debug_info->log_mutex);
170 static __poll_t cros_ec_console_log_poll(struct file *file,
173 struct cros_ec_debugfs *debug_info = file->private_data;
176 poll_wait(file, &debug_info->log_wq, wait);
178 mutex_lock(&debug_info->log_mutex);
179 if (CIRC_CNT(debug_info->log_buffer.head,
180 debug_info->log_buffer.tail,
182 mask |= EPOLLIN | EPOLLRDNORM;
183 mutex_unlock(&debug_info->log_mutex);
188 static int cros_ec_console_log_release(struct inode *inode, struct file *file)
193 static ssize_t cros_ec_pdinfo_read(struct file *file,
194 char __user *user_buf,
198 char read_buf[EC_USB_PD_MAX_PORTS * 40], *p = read_buf;
199 struct cros_ec_debugfs *debug_info = file->private_data;
200 struct cros_ec_device *ec_dev = debug_info->ec->ec_dev;
202 struct cros_ec_command msg;
204 struct ec_response_usb_pd_control_v1 resp;
205 struct ec_params_usb_pd_control params;
208 struct cros_ec_command *msg;
209 struct ec_response_usb_pd_control_v1 *resp;
210 struct ec_params_usb_pd_control *params;
214 params = (struct ec_params_usb_pd_control *)msg->data;
215 resp = (struct ec_response_usb_pd_control_v1 *)msg->data;
217 msg->command = EC_CMD_USB_PD_CONTROL;
219 msg->insize = sizeof(*resp);
220 msg->outsize = sizeof(*params);
223 * Read status from all PD ports until failure, typically caused
224 * by attempting to read status on a port that doesn't exist.
226 for (i = 0; i < EC_USB_PD_MAX_PORTS; ++i) {
232 if (cros_ec_cmd_xfer_status(ec_dev, msg) < 0)
235 p += scnprintf(p, sizeof(read_buf) + read_buf - p,
236 "p%d: %s en:%.2x role:%.2x pol:%.2x\n", i,
237 resp->state, resp->enabled, resp->role,
241 return simple_read_from_buffer(user_buf, count, ppos,
242 read_buf, p - read_buf);
245 static ssize_t cros_ec_uptime_read(struct file *file, char __user *user_buf,
246 size_t count, loff_t *ppos)
248 struct cros_ec_debugfs *debug_info = file->private_data;
249 struct cros_ec_device *ec_dev = debug_info->ec->ec_dev;
251 struct cros_ec_command cmd;
252 struct ec_response_uptime_info resp;
254 struct ec_response_uptime_info *resp;
258 resp = (struct ec_response_uptime_info *)&msg.resp;
260 msg.cmd.command = EC_CMD_GET_UPTIME_INFO;
261 msg.cmd.insize = sizeof(*resp);
263 ret = cros_ec_cmd_xfer_status(ec_dev, &msg.cmd);
267 ret = scnprintf(read_buf, sizeof(read_buf), "%u\n",
268 resp->time_since_ec_boot_ms);
270 return simple_read_from_buffer(user_buf, count, ppos, read_buf, ret);
273 static const struct file_operations cros_ec_console_log_fops = {
274 .owner = THIS_MODULE,
275 .open = cros_ec_console_log_open,
276 .read = cros_ec_console_log_read,
278 .poll = cros_ec_console_log_poll,
279 .release = cros_ec_console_log_release,
282 static const struct file_operations cros_ec_pdinfo_fops = {
283 .owner = THIS_MODULE,
285 .read = cros_ec_pdinfo_read,
286 .llseek = default_llseek,
289 static const struct file_operations cros_ec_uptime_fops = {
290 .owner = THIS_MODULE,
292 .read = cros_ec_uptime_read,
293 .llseek = default_llseek,
296 static int ec_read_version_supported(struct cros_ec_dev *ec)
298 struct ec_params_get_cmd_versions_v1 *params;
299 struct ec_response_get_cmd_versions *response;
302 struct cros_ec_command *msg;
304 msg = kzalloc(sizeof(*msg) + max(sizeof(*params), sizeof(*response)),
309 msg->command = EC_CMD_GET_CMD_VERSIONS + ec->cmd_offset;
310 msg->outsize = sizeof(*params);
311 msg->insize = sizeof(*response);
313 params = (struct ec_params_get_cmd_versions_v1 *)msg->data;
314 params->cmd = EC_CMD_CONSOLE_READ;
315 response = (struct ec_response_get_cmd_versions *)msg->data;
317 ret = cros_ec_cmd_xfer_status(ec->ec_dev, msg) >= 0 &&
318 response->version_mask & EC_VER_MASK(1);
325 static int cros_ec_create_console_log(struct cros_ec_debugfs *debug_info)
327 struct cros_ec_dev *ec = debug_info->ec;
329 int read_params_size;
330 int read_response_size;
333 * If the console log feature is not supported return silently and
334 * don't create the console_log entry.
336 if (!ec_read_version_supported(ec))
339 buf = devm_kzalloc(ec->dev, LOG_SIZE, GFP_KERNEL);
343 read_params_size = sizeof(struct ec_params_console_read_v1);
344 read_response_size = ec->ec_dev->max_response;
345 debug_info->read_msg = devm_kzalloc(ec->dev,
346 sizeof(*debug_info->read_msg) +
347 max(read_params_size, read_response_size), GFP_KERNEL);
348 if (!debug_info->read_msg)
351 debug_info->read_msg->version = 1;
352 debug_info->read_msg->command = EC_CMD_CONSOLE_READ + ec->cmd_offset;
353 debug_info->read_msg->outsize = read_params_size;
354 debug_info->read_msg->insize = read_response_size;
356 debug_info->log_buffer.buf = buf;
357 debug_info->log_buffer.head = 0;
358 debug_info->log_buffer.tail = 0;
360 mutex_init(&debug_info->log_mutex);
361 init_waitqueue_head(&debug_info->log_wq);
363 debugfs_create_file("console_log", S_IFREG | 0444, debug_info->dir,
364 debug_info, &cros_ec_console_log_fops);
366 INIT_DELAYED_WORK(&debug_info->log_poll_work,
367 cros_ec_console_log_work);
368 schedule_delayed_work(&debug_info->log_poll_work, 0);
373 static void cros_ec_cleanup_console_log(struct cros_ec_debugfs *debug_info)
375 if (debug_info->log_buffer.buf) {
376 cancel_delayed_work_sync(&debug_info->log_poll_work);
377 mutex_destroy(&debug_info->log_mutex);
381 static int cros_ec_create_panicinfo(struct cros_ec_debugfs *debug_info)
383 struct cros_ec_device *ec_dev = debug_info->ec->ec_dev;
385 struct cros_ec_command *msg;
388 insize = ec_dev->max_response;
390 msg = devm_kzalloc(debug_info->ec->dev,
391 sizeof(*msg) + insize, GFP_KERNEL);
395 msg->command = EC_CMD_GET_PANIC_INFO;
396 msg->insize = insize;
398 ret = cros_ec_cmd_xfer_status(ec_dev, msg);
408 debug_info->panicinfo_blob.data = msg->data;
409 debug_info->panicinfo_blob.size = ret;
411 debugfs_create_blob("panicinfo", S_IFREG | 0444, debug_info->dir,
412 &debug_info->panicinfo_blob);
417 devm_kfree(debug_info->ec->dev, msg);
421 static int cros_ec_debugfs_probe(struct platform_device *pd)
423 struct cros_ec_dev *ec = dev_get_drvdata(pd->dev.parent);
424 struct cros_ec_platform *ec_platform = dev_get_platdata(ec->dev);
425 const char *name = ec_platform->ec_name;
426 struct cros_ec_debugfs *debug_info;
429 debug_info = devm_kzalloc(ec->dev, sizeof(*debug_info), GFP_KERNEL);
434 debug_info->dir = debugfs_create_dir(name, NULL);
436 ret = cros_ec_create_panicinfo(debug_info);
440 ret = cros_ec_create_console_log(debug_info);
444 debugfs_create_file("pdinfo", 0444, debug_info->dir, debug_info,
445 &cros_ec_pdinfo_fops);
447 debugfs_create_file("uptime", 0444, debug_info->dir, debug_info,
448 &cros_ec_uptime_fops);
450 ec->debug_info = debug_info;
452 dev_set_drvdata(&pd->dev, ec);
457 debugfs_remove_recursive(debug_info->dir);
461 static int cros_ec_debugfs_remove(struct platform_device *pd)
463 struct cros_ec_dev *ec = dev_get_drvdata(pd->dev.parent);
465 debugfs_remove_recursive(ec->debug_info->dir);
466 cros_ec_cleanup_console_log(ec->debug_info);
471 static int __maybe_unused cros_ec_debugfs_suspend(struct device *dev)
473 struct cros_ec_dev *ec = dev_get_drvdata(dev);
475 if (ec->debug_info->log_buffer.buf)
476 cancel_delayed_work_sync(&ec->debug_info->log_poll_work);
481 static int __maybe_unused cros_ec_debugfs_resume(struct device *dev)
483 struct cros_ec_dev *ec = dev_get_drvdata(dev);
485 if (ec->debug_info->log_buffer.buf)
486 schedule_delayed_work(&ec->debug_info->log_poll_work, 0);
491 static SIMPLE_DEV_PM_OPS(cros_ec_debugfs_pm_ops,
492 cros_ec_debugfs_suspend, cros_ec_debugfs_resume);
494 static struct platform_driver cros_ec_debugfs_driver = {
497 .pm = &cros_ec_debugfs_pm_ops,
499 .probe = cros_ec_debugfs_probe,
500 .remove = cros_ec_debugfs_remove,
503 module_platform_driver(cros_ec_debugfs_driver);
505 MODULE_LICENSE("GPL");
506 MODULE_DESCRIPTION("Debug logs for ChromeOS EC");
507 MODULE_ALIAS("platform:" DRV_NAME);