1 // SPDX-License-Identifier: GPL-2.0+ 2 // Debug logs for the ChromeOS EC 3 // 4 // Copyright (C) 2015 Google, Inc. 5 6 #include <linux/circ_buf.h> 7 #include <linux/debugfs.h> 8 #include <linux/delay.h> 9 #include <linux/fs.h> 10 #include <linux/module.h> 11 #include <linux/mutex.h> 12 #include <linux/platform_data/cros_ec_commands.h> 13 #include <linux/platform_data/cros_ec_proto.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> 19 20 #define DRV_NAME "cros-ec-debugfs" 21 22 #define LOG_SHIFT 14 23 #define LOG_SIZE (1 << LOG_SHIFT) 24 #define LOG_POLL_SEC 10 25 26 #define CIRC_ADD(idx, size, value) (((idx) + (value)) & ((size) - 1)) 27 28 /** 29 * struct cros_ec_debugfs - EC debugging information. 30 * 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 39 */ 40 struct cros_ec_debugfs { 41 struct cros_ec_dev *ec; 42 struct dentry *dir; 43 /* EC log */ 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; 49 /* EC panicinfo */ 50 struct debugfs_blob_wrapper panicinfo_blob; 51 }; 52 53 /* 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. 56 */ 57 static void cros_ec_console_log_work(struct work_struct *__work) 58 { 59 struct cros_ec_debugfs *debug_info = 60 container_of(to_delayed_work(__work), 61 struct cros_ec_debugfs, 62 log_poll_work); 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, 67 }; 68 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; 72 int idx; 73 int buf_space; 74 int ret; 75 76 ret = cros_ec_cmd_xfer_status(ec->ec_dev, &snapshot_msg); 77 if (ret < 0) 78 goto resched; 79 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); 83 84 while (1) { 85 if (!buf_space) { 86 dev_info_once(ec->dev, 87 "Some logs may have been dropped...\n"); 88 break; 89 } 90 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); 95 if (ret < 0) 96 break; 97 98 /* If the buffer is empty, we're done here. */ 99 if (ret == 0 || ec_buffer[0] == '\0') 100 break; 101 102 idx = 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); 106 idx++; 107 buf_space--; 108 } 109 110 wake_up(&debug_info->log_wq); 111 } 112 113 mutex_unlock(&debug_info->log_mutex); 114 115 resched: 116 schedule_delayed_work(&debug_info->log_poll_work, 117 msecs_to_jiffies(LOG_POLL_SEC * 1000)); 118 } 119 120 static int cros_ec_console_log_open(struct inode *inode, struct file *file) 121 { 122 file->private_data = inode->i_private; 123 124 return stream_open(inode, file); 125 } 126 127 static ssize_t cros_ec_console_log_read(struct file *file, char __user *buf, 128 size_t count, loff_t *ppos) 129 { 130 struct cros_ec_debugfs *debug_info = file->private_data; 131 struct circ_buf *cb = &debug_info->log_buffer; 132 ssize_t ret; 133 134 mutex_lock(&debug_info->log_mutex); 135 136 while (!CIRC_CNT(cb->head, cb->tail, LOG_SIZE)) { 137 if (file->f_flags & O_NONBLOCK) { 138 ret = -EAGAIN; 139 goto error; 140 } 141 142 mutex_unlock(&debug_info->log_mutex); 143 144 ret = wait_event_interruptible(debug_info->log_wq, 145 CIRC_CNT(cb->head, cb->tail, LOG_SIZE)); 146 if (ret < 0) 147 return ret; 148 149 mutex_lock(&debug_info->log_mutex); 150 } 151 152 /* Only copy until the end of the circular buffer, and let userspace 153 * retry to get the rest of the data. 154 */ 155 ret = min_t(size_t, CIRC_CNT_TO_END(cb->head, cb->tail, LOG_SIZE), 156 count); 157 158 if (copy_to_user(buf, cb->buf + cb->tail, ret)) { 159 ret = -EFAULT; 160 goto error; 161 } 162 163 cb->tail = CIRC_ADD(cb->tail, LOG_SIZE, ret); 164 165 error: 166 mutex_unlock(&debug_info->log_mutex); 167 return ret; 168 } 169 170 static __poll_t cros_ec_console_log_poll(struct file *file, 171 poll_table *wait) 172 { 173 struct cros_ec_debugfs *debug_info = file->private_data; 174 __poll_t mask = 0; 175 176 poll_wait(file, &debug_info->log_wq, wait); 177 178 mutex_lock(&debug_info->log_mutex); 179 if (CIRC_CNT(debug_info->log_buffer.head, 180 debug_info->log_buffer.tail, 181 LOG_SIZE)) 182 mask |= EPOLLIN | EPOLLRDNORM; 183 mutex_unlock(&debug_info->log_mutex); 184 185 return mask; 186 } 187 188 static int cros_ec_console_log_release(struct inode *inode, struct file *file) 189 { 190 return 0; 191 } 192 193 static ssize_t cros_ec_pdinfo_read(struct file *file, 194 char __user *user_buf, 195 size_t count, 196 loff_t *ppos) 197 { 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; 201 struct { 202 struct cros_ec_command msg; 203 union { 204 struct ec_response_usb_pd_control_v1 resp; 205 struct ec_params_usb_pd_control params; 206 }; 207 } __packed ec_buf; 208 struct cros_ec_command *msg; 209 struct ec_response_usb_pd_control_v1 *resp; 210 struct ec_params_usb_pd_control *params; 211 int i; 212 213 msg = &ec_buf.msg; 214 params = (struct ec_params_usb_pd_control *)msg->data; 215 resp = (struct ec_response_usb_pd_control_v1 *)msg->data; 216 217 msg->command = EC_CMD_USB_PD_CONTROL; 218 msg->version = 1; 219 msg->insize = sizeof(*resp); 220 msg->outsize = sizeof(*params); 221 222 /* 223 * Read status from all PD ports until failure, typically caused 224 * by attempting to read status on a port that doesn't exist. 225 */ 226 for (i = 0; i < EC_USB_PD_MAX_PORTS; ++i) { 227 params->port = i; 228 params->role = 0; 229 params->mux = 0; 230 params->swap = 0; 231 232 if (cros_ec_cmd_xfer_status(ec_dev, msg) < 0) 233 break; 234 235 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, 238 resp->polarity); 239 } 240 241 return simple_read_from_buffer(user_buf, count, ppos, 242 read_buf, p - read_buf); 243 } 244 245 static bool cros_ec_uptime_is_supported(struct cros_ec_device *ec_dev) 246 { 247 struct { 248 struct cros_ec_command cmd; 249 struct ec_response_uptime_info resp; 250 } __packed msg = {}; 251 int ret; 252 253 msg.cmd.command = EC_CMD_GET_UPTIME_INFO; 254 msg.cmd.insize = sizeof(msg.resp); 255 256 ret = cros_ec_cmd_xfer_status(ec_dev, &msg.cmd); 257 if (ret == -EPROTO && msg.cmd.result == EC_RES_INVALID_COMMAND) 258 return false; 259 260 /* Other errors maybe a transient error, do not rule about support. */ 261 return true; 262 } 263 264 static ssize_t cros_ec_uptime_read(struct file *file, char __user *user_buf, 265 size_t count, loff_t *ppos) 266 { 267 struct cros_ec_debugfs *debug_info = file->private_data; 268 struct cros_ec_device *ec_dev = debug_info->ec->ec_dev; 269 struct { 270 struct cros_ec_command cmd; 271 struct ec_response_uptime_info resp; 272 } __packed msg = {}; 273 struct ec_response_uptime_info *resp; 274 char read_buf[32]; 275 int ret; 276 277 resp = (struct ec_response_uptime_info *)&msg.resp; 278 279 msg.cmd.command = EC_CMD_GET_UPTIME_INFO; 280 msg.cmd.insize = sizeof(*resp); 281 282 ret = cros_ec_cmd_xfer_status(ec_dev, &msg.cmd); 283 if (ret < 0) 284 return ret; 285 286 ret = scnprintf(read_buf, sizeof(read_buf), "%u\n", 287 resp->time_since_ec_boot_ms); 288 289 return simple_read_from_buffer(user_buf, count, ppos, read_buf, ret); 290 } 291 292 static const struct file_operations cros_ec_console_log_fops = { 293 .owner = THIS_MODULE, 294 .open = cros_ec_console_log_open, 295 .read = cros_ec_console_log_read, 296 .llseek = no_llseek, 297 .poll = cros_ec_console_log_poll, 298 .release = cros_ec_console_log_release, 299 }; 300 301 static const struct file_operations cros_ec_pdinfo_fops = { 302 .owner = THIS_MODULE, 303 .open = simple_open, 304 .read = cros_ec_pdinfo_read, 305 .llseek = default_llseek, 306 }; 307 308 static const struct file_operations cros_ec_uptime_fops = { 309 .owner = THIS_MODULE, 310 .open = simple_open, 311 .read = cros_ec_uptime_read, 312 .llseek = default_llseek, 313 }; 314 315 static int ec_read_version_supported(struct cros_ec_dev *ec) 316 { 317 struct ec_params_get_cmd_versions_v1 *params; 318 struct ec_response_get_cmd_versions *response; 319 int ret; 320 321 struct cros_ec_command *msg; 322 323 msg = kzalloc(sizeof(*msg) + max(sizeof(*params), sizeof(*response)), 324 GFP_KERNEL); 325 if (!msg) 326 return 0; 327 328 msg->command = EC_CMD_GET_CMD_VERSIONS + ec->cmd_offset; 329 msg->outsize = sizeof(*params); 330 msg->insize = sizeof(*response); 331 332 params = (struct ec_params_get_cmd_versions_v1 *)msg->data; 333 params->cmd = EC_CMD_CONSOLE_READ; 334 response = (struct ec_response_get_cmd_versions *)msg->data; 335 336 ret = cros_ec_cmd_xfer_status(ec->ec_dev, msg) >= 0 && 337 response->version_mask & EC_VER_MASK(1); 338 339 kfree(msg); 340 341 return ret; 342 } 343 344 static int cros_ec_create_console_log(struct cros_ec_debugfs *debug_info) 345 { 346 struct cros_ec_dev *ec = debug_info->ec; 347 char *buf; 348 int read_params_size; 349 int read_response_size; 350 351 /* 352 * If the console log feature is not supported return silently and 353 * don't create the console_log entry. 354 */ 355 if (!ec_read_version_supported(ec)) 356 return 0; 357 358 buf = devm_kzalloc(ec->dev, LOG_SIZE, GFP_KERNEL); 359 if (!buf) 360 return -ENOMEM; 361 362 read_params_size = sizeof(struct ec_params_console_read_v1); 363 read_response_size = ec->ec_dev->max_response; 364 debug_info->read_msg = devm_kzalloc(ec->dev, 365 sizeof(*debug_info->read_msg) + 366 max(read_params_size, read_response_size), GFP_KERNEL); 367 if (!debug_info->read_msg) 368 return -ENOMEM; 369 370 debug_info->read_msg->version = 1; 371 debug_info->read_msg->command = EC_CMD_CONSOLE_READ + ec->cmd_offset; 372 debug_info->read_msg->outsize = read_params_size; 373 debug_info->read_msg->insize = read_response_size; 374 375 debug_info->log_buffer.buf = buf; 376 debug_info->log_buffer.head = 0; 377 debug_info->log_buffer.tail = 0; 378 379 mutex_init(&debug_info->log_mutex); 380 init_waitqueue_head(&debug_info->log_wq); 381 382 debugfs_create_file("console_log", S_IFREG | 0444, debug_info->dir, 383 debug_info, &cros_ec_console_log_fops); 384 385 INIT_DELAYED_WORK(&debug_info->log_poll_work, 386 cros_ec_console_log_work); 387 schedule_delayed_work(&debug_info->log_poll_work, 0); 388 389 return 0; 390 } 391 392 static void cros_ec_cleanup_console_log(struct cros_ec_debugfs *debug_info) 393 { 394 if (debug_info->log_buffer.buf) { 395 cancel_delayed_work_sync(&debug_info->log_poll_work); 396 mutex_destroy(&debug_info->log_mutex); 397 } 398 } 399 400 static int cros_ec_create_panicinfo(struct cros_ec_debugfs *debug_info) 401 { 402 struct cros_ec_device *ec_dev = debug_info->ec->ec_dev; 403 int ret; 404 struct cros_ec_command *msg; 405 int insize; 406 407 insize = ec_dev->max_response; 408 409 msg = devm_kzalloc(debug_info->ec->dev, 410 sizeof(*msg) + insize, GFP_KERNEL); 411 if (!msg) 412 return -ENOMEM; 413 414 msg->command = EC_CMD_GET_PANIC_INFO; 415 msg->insize = insize; 416 417 ret = cros_ec_cmd_xfer_status(ec_dev, msg); 418 if (ret < 0) { 419 ret = 0; 420 goto free; 421 } 422 423 /* No panic data */ 424 if (ret == 0) 425 goto free; 426 427 debug_info->panicinfo_blob.data = msg->data; 428 debug_info->panicinfo_blob.size = ret; 429 430 debugfs_create_blob("panicinfo", S_IFREG | 0444, debug_info->dir, 431 &debug_info->panicinfo_blob); 432 433 return 0; 434 435 free: 436 devm_kfree(debug_info->ec->dev, msg); 437 return ret; 438 } 439 440 static int cros_ec_debugfs_probe(struct platform_device *pd) 441 { 442 struct cros_ec_dev *ec = dev_get_drvdata(pd->dev.parent); 443 struct cros_ec_platform *ec_platform = dev_get_platdata(ec->dev); 444 const char *name = ec_platform->ec_name; 445 struct cros_ec_debugfs *debug_info; 446 int ret; 447 448 debug_info = devm_kzalloc(ec->dev, sizeof(*debug_info), GFP_KERNEL); 449 if (!debug_info) 450 return -ENOMEM; 451 452 debug_info->ec = ec; 453 debug_info->dir = debugfs_create_dir(name, NULL); 454 455 ret = cros_ec_create_panicinfo(debug_info); 456 if (ret) 457 goto remove_debugfs; 458 459 ret = cros_ec_create_console_log(debug_info); 460 if (ret) 461 goto remove_debugfs; 462 463 debugfs_create_file("pdinfo", 0444, debug_info->dir, debug_info, 464 &cros_ec_pdinfo_fops); 465 466 if (cros_ec_uptime_is_supported(ec->ec_dev)) 467 debugfs_create_file("uptime", 0444, debug_info->dir, debug_info, 468 &cros_ec_uptime_fops); 469 470 debugfs_create_x32("last_resume_result", 0444, debug_info->dir, 471 &ec->ec_dev->last_resume_result); 472 473 ec->debug_info = debug_info; 474 475 dev_set_drvdata(&pd->dev, ec); 476 477 return 0; 478 479 remove_debugfs: 480 debugfs_remove_recursive(debug_info->dir); 481 return ret; 482 } 483 484 static int cros_ec_debugfs_remove(struct platform_device *pd) 485 { 486 struct cros_ec_dev *ec = dev_get_drvdata(pd->dev.parent); 487 488 debugfs_remove_recursive(ec->debug_info->dir); 489 cros_ec_cleanup_console_log(ec->debug_info); 490 491 return 0; 492 } 493 494 static int __maybe_unused cros_ec_debugfs_suspend(struct device *dev) 495 { 496 struct cros_ec_dev *ec = dev_get_drvdata(dev); 497 498 if (ec->debug_info->log_buffer.buf) 499 cancel_delayed_work_sync(&ec->debug_info->log_poll_work); 500 501 return 0; 502 } 503 504 static int __maybe_unused cros_ec_debugfs_resume(struct device *dev) 505 { 506 struct cros_ec_dev *ec = dev_get_drvdata(dev); 507 508 if (ec->debug_info->log_buffer.buf) 509 schedule_delayed_work(&ec->debug_info->log_poll_work, 0); 510 511 return 0; 512 } 513 514 static SIMPLE_DEV_PM_OPS(cros_ec_debugfs_pm_ops, 515 cros_ec_debugfs_suspend, cros_ec_debugfs_resume); 516 517 static struct platform_driver cros_ec_debugfs_driver = { 518 .driver = { 519 .name = DRV_NAME, 520 .pm = &cros_ec_debugfs_pm_ops, 521 }, 522 .probe = cros_ec_debugfs_probe, 523 .remove = cros_ec_debugfs_remove, 524 }; 525 526 module_platform_driver(cros_ec_debugfs_driver); 527 528 MODULE_LICENSE("GPL"); 529 MODULE_DESCRIPTION("Debug logs for ChromeOS EC"); 530 MODULE_ALIAS("platform:" DRV_NAME); 531