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 /* waitqueue for log readers */ 29 static DECLARE_WAIT_QUEUE_HEAD(cros_ec_debugfs_log_wq); 30 31 /** 32 * struct cros_ec_debugfs - EC debugging information. 33 * 34 * @ec: EC device this debugfs information belongs to 35 * @dir: dentry for debugfs files 36 * @log_buffer: circular buffer for console log information 37 * @read_msg: preallocated EC command and buffer to read console log 38 * @log_mutex: mutex to protect circular buffer 39 * @log_poll_work: recurring task to poll EC for new console log data 40 * @panicinfo_blob: panicinfo debugfs blob 41 */ 42 struct cros_ec_debugfs { 43 struct cros_ec_dev *ec; 44 struct dentry *dir; 45 /* EC log */ 46 struct circ_buf log_buffer; 47 struct cros_ec_command *read_msg; 48 struct mutex log_mutex; 49 struct delayed_work log_poll_work; 50 /* EC panicinfo */ 51 struct debugfs_blob_wrapper panicinfo_blob; 52 }; 53 54 /* 55 * We need to make sure that the EC log buffer on the UART is large enough, 56 * so that it is unlikely enough to overlow within LOG_POLL_SEC. 57 */ 58 static void cros_ec_console_log_work(struct work_struct *__work) 59 { 60 struct cros_ec_debugfs *debug_info = 61 container_of(to_delayed_work(__work), 62 struct cros_ec_debugfs, 63 log_poll_work); 64 struct cros_ec_dev *ec = debug_info->ec; 65 struct circ_buf *cb = &debug_info->log_buffer; 66 struct cros_ec_command snapshot_msg = { 67 .command = EC_CMD_CONSOLE_SNAPSHOT + ec->cmd_offset, 68 }; 69 70 struct ec_params_console_read_v1 *read_params = 71 (struct ec_params_console_read_v1 *)debug_info->read_msg->data; 72 uint8_t *ec_buffer = (uint8_t *)debug_info->read_msg->data; 73 int idx; 74 int buf_space; 75 int ret; 76 77 ret = cros_ec_cmd_xfer_status(ec->ec_dev, &snapshot_msg); 78 if (ret < 0) 79 goto resched; 80 81 /* Loop until we have read everything, or there's an error. */ 82 mutex_lock(&debug_info->log_mutex); 83 buf_space = CIRC_SPACE(cb->head, cb->tail, LOG_SIZE); 84 85 while (1) { 86 if (!buf_space) { 87 dev_info_once(ec->dev, 88 "Some logs may have been dropped...\n"); 89 break; 90 } 91 92 memset(read_params, '\0', sizeof(*read_params)); 93 read_params->subcmd = CONSOLE_READ_RECENT; 94 ret = cros_ec_cmd_xfer_status(ec->ec_dev, 95 debug_info->read_msg); 96 if (ret < 0) 97 break; 98 99 /* If the buffer is empty, we're done here. */ 100 if (ret == 0 || ec_buffer[0] == '\0') 101 break; 102 103 idx = 0; 104 while (idx < ret && ec_buffer[idx] != '\0' && buf_space > 0) { 105 cb->buf[cb->head] = ec_buffer[idx]; 106 cb->head = CIRC_ADD(cb->head, LOG_SIZE, 1); 107 idx++; 108 buf_space--; 109 } 110 111 wake_up(&cros_ec_debugfs_log_wq); 112 } 113 114 mutex_unlock(&debug_info->log_mutex); 115 116 resched: 117 schedule_delayed_work(&debug_info->log_poll_work, 118 msecs_to_jiffies(LOG_POLL_SEC * 1000)); 119 } 120 121 static int cros_ec_console_log_open(struct inode *inode, struct file *file) 122 { 123 file->private_data = inode->i_private; 124 125 return stream_open(inode, file); 126 } 127 128 static ssize_t cros_ec_console_log_read(struct file *file, char __user *buf, 129 size_t count, loff_t *ppos) 130 { 131 struct cros_ec_debugfs *debug_info = file->private_data; 132 struct circ_buf *cb = &debug_info->log_buffer; 133 ssize_t ret; 134 135 mutex_lock(&debug_info->log_mutex); 136 137 while (!CIRC_CNT(cb->head, cb->tail, LOG_SIZE)) { 138 if (file->f_flags & O_NONBLOCK) { 139 ret = -EAGAIN; 140 goto error; 141 } 142 143 mutex_unlock(&debug_info->log_mutex); 144 145 ret = wait_event_interruptible(cros_ec_debugfs_log_wq, 146 CIRC_CNT(cb->head, cb->tail, LOG_SIZE)); 147 if (ret < 0) 148 return ret; 149 150 mutex_lock(&debug_info->log_mutex); 151 } 152 153 /* Only copy until the end of the circular buffer, and let userspace 154 * retry to get the rest of the data. 155 */ 156 ret = min_t(size_t, CIRC_CNT_TO_END(cb->head, cb->tail, LOG_SIZE), 157 count); 158 159 if (copy_to_user(buf, cb->buf + cb->tail, ret)) { 160 ret = -EFAULT; 161 goto error; 162 } 163 164 cb->tail = CIRC_ADD(cb->tail, LOG_SIZE, ret); 165 166 error: 167 mutex_unlock(&debug_info->log_mutex); 168 return ret; 169 } 170 171 static __poll_t cros_ec_console_log_poll(struct file *file, 172 poll_table *wait) 173 { 174 struct cros_ec_debugfs *debug_info = file->private_data; 175 __poll_t mask = 0; 176 177 poll_wait(file, &cros_ec_debugfs_log_wq, wait); 178 179 mutex_lock(&debug_info->log_mutex); 180 if (CIRC_CNT(debug_info->log_buffer.head, 181 debug_info->log_buffer.tail, 182 LOG_SIZE)) 183 mask |= EPOLLIN | EPOLLRDNORM; 184 mutex_unlock(&debug_info->log_mutex); 185 186 return mask; 187 } 188 189 static int cros_ec_console_log_release(struct inode *inode, struct file *file) 190 { 191 return 0; 192 } 193 194 static ssize_t cros_ec_pdinfo_read(struct file *file, 195 char __user *user_buf, 196 size_t count, 197 loff_t *ppos) 198 { 199 char read_buf[EC_USB_PD_MAX_PORTS * 40], *p = read_buf; 200 struct cros_ec_debugfs *debug_info = file->private_data; 201 struct cros_ec_device *ec_dev = debug_info->ec->ec_dev; 202 struct { 203 struct cros_ec_command msg; 204 union { 205 struct ec_response_usb_pd_control_v1 resp; 206 struct ec_params_usb_pd_control params; 207 }; 208 } __packed ec_buf; 209 struct cros_ec_command *msg; 210 struct ec_response_usb_pd_control_v1 *resp; 211 struct ec_params_usb_pd_control *params; 212 int i; 213 214 msg = &ec_buf.msg; 215 params = (struct ec_params_usb_pd_control *)msg->data; 216 resp = (struct ec_response_usb_pd_control_v1 *)msg->data; 217 218 msg->command = EC_CMD_USB_PD_CONTROL; 219 msg->version = 1; 220 msg->insize = sizeof(*resp); 221 msg->outsize = sizeof(*params); 222 223 /* 224 * Read status from all PD ports until failure, typically caused 225 * by attempting to read status on a port that doesn't exist. 226 */ 227 for (i = 0; i < EC_USB_PD_MAX_PORTS; ++i) { 228 params->port = i; 229 params->role = 0; 230 params->mux = 0; 231 params->swap = 0; 232 233 if (cros_ec_cmd_xfer_status(ec_dev, msg) < 0) 234 break; 235 236 p += scnprintf(p, sizeof(read_buf) + read_buf - p, 237 "p%d: %s en:%.2x role:%.2x pol:%.2x\n", i, 238 resp->state, resp->enabled, resp->role, 239 resp->polarity); 240 } 241 242 return simple_read_from_buffer(user_buf, count, ppos, 243 read_buf, p - read_buf); 244 } 245 246 static bool cros_ec_uptime_is_supported(struct cros_ec_device *ec_dev) 247 { 248 struct { 249 struct cros_ec_command cmd; 250 struct ec_response_uptime_info resp; 251 } __packed msg = {}; 252 int ret; 253 254 msg.cmd.command = EC_CMD_GET_UPTIME_INFO; 255 msg.cmd.insize = sizeof(msg.resp); 256 257 ret = cros_ec_cmd_xfer_status(ec_dev, &msg.cmd); 258 if (ret == -EPROTO && msg.cmd.result == EC_RES_INVALID_COMMAND) 259 return false; 260 261 /* Other errors maybe a transient error, do not rule about support. */ 262 return true; 263 } 264 265 static ssize_t cros_ec_uptime_read(struct file *file, char __user *user_buf, 266 size_t count, loff_t *ppos) 267 { 268 struct cros_ec_debugfs *debug_info = file->private_data; 269 struct cros_ec_device *ec_dev = debug_info->ec->ec_dev; 270 struct { 271 struct cros_ec_command cmd; 272 struct ec_response_uptime_info resp; 273 } __packed msg = {}; 274 struct ec_response_uptime_info *resp; 275 char read_buf[32]; 276 int ret; 277 278 resp = (struct ec_response_uptime_info *)&msg.resp; 279 280 msg.cmd.command = EC_CMD_GET_UPTIME_INFO; 281 msg.cmd.insize = sizeof(*resp); 282 283 ret = cros_ec_cmd_xfer_status(ec_dev, &msg.cmd); 284 if (ret < 0) 285 return ret; 286 287 ret = scnprintf(read_buf, sizeof(read_buf), "%u\n", 288 resp->time_since_ec_boot_ms); 289 290 return simple_read_from_buffer(user_buf, count, ppos, read_buf, ret); 291 } 292 293 static const struct file_operations cros_ec_console_log_fops = { 294 .owner = THIS_MODULE, 295 .open = cros_ec_console_log_open, 296 .read = cros_ec_console_log_read, 297 .llseek = no_llseek, 298 .poll = cros_ec_console_log_poll, 299 .release = cros_ec_console_log_release, 300 }; 301 302 static const struct file_operations cros_ec_pdinfo_fops = { 303 .owner = THIS_MODULE, 304 .open = simple_open, 305 .read = cros_ec_pdinfo_read, 306 .llseek = default_llseek, 307 }; 308 309 static const struct file_operations cros_ec_uptime_fops = { 310 .owner = THIS_MODULE, 311 .open = simple_open, 312 .read = cros_ec_uptime_read, 313 .llseek = default_llseek, 314 }; 315 316 static int ec_read_version_supported(struct cros_ec_dev *ec) 317 { 318 struct ec_params_get_cmd_versions_v1 *params; 319 struct ec_response_get_cmd_versions *response; 320 int ret; 321 322 struct cros_ec_command *msg; 323 324 msg = kzalloc(sizeof(*msg) + max(sizeof(*params), sizeof(*response)), 325 GFP_KERNEL); 326 if (!msg) 327 return 0; 328 329 msg->command = EC_CMD_GET_CMD_VERSIONS + ec->cmd_offset; 330 msg->outsize = sizeof(*params); 331 msg->insize = sizeof(*response); 332 333 params = (struct ec_params_get_cmd_versions_v1 *)msg->data; 334 params->cmd = EC_CMD_CONSOLE_READ; 335 response = (struct ec_response_get_cmd_versions *)msg->data; 336 337 ret = cros_ec_cmd_xfer_status(ec->ec_dev, msg) >= 0 && 338 response->version_mask & EC_VER_MASK(1); 339 340 kfree(msg); 341 342 return ret; 343 } 344 345 static int cros_ec_create_console_log(struct cros_ec_debugfs *debug_info) 346 { 347 struct cros_ec_dev *ec = debug_info->ec; 348 char *buf; 349 int read_params_size; 350 int read_response_size; 351 352 /* 353 * If the console log feature is not supported return silently and 354 * don't create the console_log entry. 355 */ 356 if (!ec_read_version_supported(ec)) 357 return 0; 358 359 buf = devm_kzalloc(ec->dev, LOG_SIZE, GFP_KERNEL); 360 if (!buf) 361 return -ENOMEM; 362 363 read_params_size = sizeof(struct ec_params_console_read_v1); 364 read_response_size = ec->ec_dev->max_response; 365 debug_info->read_msg = devm_kzalloc(ec->dev, 366 sizeof(*debug_info->read_msg) + 367 max(read_params_size, read_response_size), GFP_KERNEL); 368 if (!debug_info->read_msg) 369 return -ENOMEM; 370 371 debug_info->read_msg->version = 1; 372 debug_info->read_msg->command = EC_CMD_CONSOLE_READ + ec->cmd_offset; 373 debug_info->read_msg->outsize = read_params_size; 374 debug_info->read_msg->insize = read_response_size; 375 376 debug_info->log_buffer.buf = buf; 377 debug_info->log_buffer.head = 0; 378 debug_info->log_buffer.tail = 0; 379 380 mutex_init(&debug_info->log_mutex); 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