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/mfd/cros_ec.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> 20 21 #define DRV_NAME "cros-ec-debugfs" 22 23 #define LOG_SHIFT 14 24 #define LOG_SIZE (1 << LOG_SHIFT) 25 #define LOG_POLL_SEC 10 26 27 #define CIRC_ADD(idx, size, value) (((idx) + (value)) & ((size) - 1)) 28 29 /** 30 * struct cros_ec_debugfs - EC debugging information. 31 * 32 * @ec: EC device this debugfs information belongs to 33 * @dir: dentry for debugfs files 34 * @log_buffer: circular buffer for console log information 35 * @read_msg: preallocated EC command and buffer to read console log 36 * @log_mutex: mutex to protect circular buffer 37 * @log_wq: waitqueue for log readers 38 * @log_poll_work: recurring task to poll EC for new console log data 39 * @panicinfo_blob: panicinfo debugfs blob 40 */ 41 struct cros_ec_debugfs { 42 struct cros_ec_dev *ec; 43 struct dentry *dir; 44 /* EC log */ 45 struct circ_buf log_buffer; 46 struct cros_ec_command *read_msg; 47 struct mutex log_mutex; 48 wait_queue_head_t log_wq; 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(&debug_info->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(debug_info->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, &debug_info->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 ssize_t cros_ec_uptime_read(struct file *file, char __user *user_buf, 247 size_t count, loff_t *ppos) 248 { 249 struct cros_ec_debugfs *debug_info = file->private_data; 250 struct cros_ec_device *ec_dev = debug_info->ec->ec_dev; 251 struct { 252 struct cros_ec_command cmd; 253 struct ec_response_uptime_info resp; 254 } __packed msg = {}; 255 struct ec_response_uptime_info *resp; 256 char read_buf[32]; 257 int ret; 258 259 resp = (struct ec_response_uptime_info *)&msg.resp; 260 261 msg.cmd.command = EC_CMD_GET_UPTIME_INFO; 262 msg.cmd.insize = sizeof(*resp); 263 264 ret = cros_ec_cmd_xfer_status(ec_dev, &msg.cmd); 265 if (ret < 0) 266 return ret; 267 268 ret = scnprintf(read_buf, sizeof(read_buf), "%u\n", 269 resp->time_since_ec_boot_ms); 270 271 return simple_read_from_buffer(user_buf, count, ppos, read_buf, ret); 272 } 273 274 static const struct file_operations cros_ec_console_log_fops = { 275 .owner = THIS_MODULE, 276 .open = cros_ec_console_log_open, 277 .read = cros_ec_console_log_read, 278 .llseek = no_llseek, 279 .poll = cros_ec_console_log_poll, 280 .release = cros_ec_console_log_release, 281 }; 282 283 static const struct file_operations cros_ec_pdinfo_fops = { 284 .owner = THIS_MODULE, 285 .open = simple_open, 286 .read = cros_ec_pdinfo_read, 287 .llseek = default_llseek, 288 }; 289 290 static const struct file_operations cros_ec_uptime_fops = { 291 .owner = THIS_MODULE, 292 .open = simple_open, 293 .read = cros_ec_uptime_read, 294 .llseek = default_llseek, 295 }; 296 297 static int ec_read_version_supported(struct cros_ec_dev *ec) 298 { 299 struct ec_params_get_cmd_versions_v1 *params; 300 struct ec_response_get_cmd_versions *response; 301 int ret; 302 303 struct cros_ec_command *msg; 304 305 msg = kzalloc(sizeof(*msg) + max(sizeof(*params), sizeof(*response)), 306 GFP_KERNEL); 307 if (!msg) 308 return 0; 309 310 msg->command = EC_CMD_GET_CMD_VERSIONS + ec->cmd_offset; 311 msg->outsize = sizeof(*params); 312 msg->insize = sizeof(*response); 313 314 params = (struct ec_params_get_cmd_versions_v1 *)msg->data; 315 params->cmd = EC_CMD_CONSOLE_READ; 316 response = (struct ec_response_get_cmd_versions *)msg->data; 317 318 ret = cros_ec_cmd_xfer_status(ec->ec_dev, msg) >= 0 && 319 response->version_mask & EC_VER_MASK(1); 320 321 kfree(msg); 322 323 return ret; 324 } 325 326 static int cros_ec_create_console_log(struct cros_ec_debugfs *debug_info) 327 { 328 struct cros_ec_dev *ec = debug_info->ec; 329 char *buf; 330 int read_params_size; 331 int read_response_size; 332 333 /* 334 * If the console log feature is not supported return silently and 335 * don't create the console_log entry. 336 */ 337 if (!ec_read_version_supported(ec)) 338 return 0; 339 340 buf = devm_kzalloc(ec->dev, LOG_SIZE, GFP_KERNEL); 341 if (!buf) 342 return -ENOMEM; 343 344 read_params_size = sizeof(struct ec_params_console_read_v1); 345 read_response_size = ec->ec_dev->max_response; 346 debug_info->read_msg = devm_kzalloc(ec->dev, 347 sizeof(*debug_info->read_msg) + 348 max(read_params_size, read_response_size), GFP_KERNEL); 349 if (!debug_info->read_msg) 350 return -ENOMEM; 351 352 debug_info->read_msg->version = 1; 353 debug_info->read_msg->command = EC_CMD_CONSOLE_READ + ec->cmd_offset; 354 debug_info->read_msg->outsize = read_params_size; 355 debug_info->read_msg->insize = read_response_size; 356 357 debug_info->log_buffer.buf = buf; 358 debug_info->log_buffer.head = 0; 359 debug_info->log_buffer.tail = 0; 360 361 mutex_init(&debug_info->log_mutex); 362 init_waitqueue_head(&debug_info->log_wq); 363 364 debugfs_create_file("console_log", S_IFREG | 0444, debug_info->dir, 365 debug_info, &cros_ec_console_log_fops); 366 367 INIT_DELAYED_WORK(&debug_info->log_poll_work, 368 cros_ec_console_log_work); 369 schedule_delayed_work(&debug_info->log_poll_work, 0); 370 371 return 0; 372 } 373 374 static void cros_ec_cleanup_console_log(struct cros_ec_debugfs *debug_info) 375 { 376 if (debug_info->log_buffer.buf) { 377 cancel_delayed_work_sync(&debug_info->log_poll_work); 378 mutex_destroy(&debug_info->log_mutex); 379 } 380 } 381 382 static int cros_ec_create_panicinfo(struct cros_ec_debugfs *debug_info) 383 { 384 struct cros_ec_device *ec_dev = debug_info->ec->ec_dev; 385 int ret; 386 struct cros_ec_command *msg; 387 int insize; 388 389 insize = ec_dev->max_response; 390 391 msg = devm_kzalloc(debug_info->ec->dev, 392 sizeof(*msg) + insize, GFP_KERNEL); 393 if (!msg) 394 return -ENOMEM; 395 396 msg->command = EC_CMD_GET_PANIC_INFO; 397 msg->insize = insize; 398 399 ret = cros_ec_cmd_xfer_status(ec_dev, msg); 400 if (ret < 0) { 401 ret = 0; 402 goto free; 403 } 404 405 /* No panic data */ 406 if (ret == 0) 407 goto free; 408 409 debug_info->panicinfo_blob.data = msg->data; 410 debug_info->panicinfo_blob.size = ret; 411 412 debugfs_create_blob("panicinfo", S_IFREG | 0444, debug_info->dir, 413 &debug_info->panicinfo_blob); 414 415 return 0; 416 417 free: 418 devm_kfree(debug_info->ec->dev, msg); 419 return ret; 420 } 421 422 static int cros_ec_debugfs_probe(struct platform_device *pd) 423 { 424 struct cros_ec_dev *ec = dev_get_drvdata(pd->dev.parent); 425 struct cros_ec_platform *ec_platform = dev_get_platdata(ec->dev); 426 const char *name = ec_platform->ec_name; 427 struct cros_ec_debugfs *debug_info; 428 int ret; 429 430 debug_info = devm_kzalloc(ec->dev, sizeof(*debug_info), GFP_KERNEL); 431 if (!debug_info) 432 return -ENOMEM; 433 434 debug_info->ec = ec; 435 debug_info->dir = debugfs_create_dir(name, NULL); 436 437 ret = cros_ec_create_panicinfo(debug_info); 438 if (ret) 439 goto remove_debugfs; 440 441 ret = cros_ec_create_console_log(debug_info); 442 if (ret) 443 goto remove_debugfs; 444 445 debugfs_create_file("pdinfo", 0444, debug_info->dir, debug_info, 446 &cros_ec_pdinfo_fops); 447 448 debugfs_create_file("uptime", 0444, debug_info->dir, debug_info, 449 &cros_ec_uptime_fops); 450 451 debugfs_create_x32("last_resume_result", 0444, debug_info->dir, 452 &ec->ec_dev->last_resume_result); 453 454 ec->debug_info = debug_info; 455 456 dev_set_drvdata(&pd->dev, ec); 457 458 return 0; 459 460 remove_debugfs: 461 debugfs_remove_recursive(debug_info->dir); 462 return ret; 463 } 464 465 static int cros_ec_debugfs_remove(struct platform_device *pd) 466 { 467 struct cros_ec_dev *ec = dev_get_drvdata(pd->dev.parent); 468 469 debugfs_remove_recursive(ec->debug_info->dir); 470 cros_ec_cleanup_console_log(ec->debug_info); 471 472 return 0; 473 } 474 475 static int __maybe_unused cros_ec_debugfs_suspend(struct device *dev) 476 { 477 struct cros_ec_dev *ec = dev_get_drvdata(dev); 478 479 if (ec->debug_info->log_buffer.buf) 480 cancel_delayed_work_sync(&ec->debug_info->log_poll_work); 481 482 return 0; 483 } 484 485 static int __maybe_unused cros_ec_debugfs_resume(struct device *dev) 486 { 487 struct cros_ec_dev *ec = dev_get_drvdata(dev); 488 489 if (ec->debug_info->log_buffer.buf) 490 schedule_delayed_work(&ec->debug_info->log_poll_work, 0); 491 492 return 0; 493 } 494 495 static SIMPLE_DEV_PM_OPS(cros_ec_debugfs_pm_ops, 496 cros_ec_debugfs_suspend, cros_ec_debugfs_resume); 497 498 static struct platform_driver cros_ec_debugfs_driver = { 499 .driver = { 500 .name = DRV_NAME, 501 .pm = &cros_ec_debugfs_pm_ops, 502 }, 503 .probe = cros_ec_debugfs_probe, 504 .remove = cros_ec_debugfs_remove, 505 }; 506 507 module_platform_driver(cros_ec_debugfs_driver); 508 509 MODULE_LICENSE("GPL"); 510 MODULE_DESCRIPTION("Debug logs for ChromeOS EC"); 511 MODULE_ALIAS("platform:" DRV_NAME); 512