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1// SPDX-License-Identifier: GPL-2.0+2// Debug logs for the ChromeOS EC3//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/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>20 21#define DRV_NAME "cros-ec-debugfs"22 23#define LOG_SHIFT 1424#define LOG_SIZE (1 << LOG_SHIFT)25#define LOG_POLL_SEC 1026 27#define CIRC_ADD(idx, size, value) (((idx) + (value)) & ((size) - 1))28 29static unsigned int log_poll_period_ms = LOG_POLL_SEC * MSEC_PER_SEC;30module_param(log_poll_period_ms, uint, 0644);31MODULE_PARM_DESC(log_poll_period_ms, "EC log polling period(ms)");32 33/* waitqueue for log readers */34static DECLARE_WAIT_QUEUE_HEAD(cros_ec_debugfs_log_wq);35 36/**37 * struct cros_ec_debugfs - EC debugging information.38 *39 * @ec: EC device this debugfs information belongs to40 * @dir: dentry for debugfs files41 * @log_buffer: circular buffer for console log information42 * @read_msg: preallocated EC command and buffer to read console log43 * @log_mutex: mutex to protect circular buffer44 * @log_poll_work: recurring task to poll EC for new console log data45 * @panicinfo_blob: panicinfo debugfs blob46 * @notifier_panic: notifier_block to let kernel to flush buffered log47 * when EC panic48 */49struct cros_ec_debugfs {50 struct cros_ec_dev *ec;51 struct dentry *dir;52 /* EC log */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;57 /* EC panicinfo */58 struct debugfs_blob_wrapper panicinfo_blob;59 struct notifier_block notifier_panic;60};61 62/*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.65 */66static void cros_ec_console_log_work(struct work_struct *__work)67{68 struct cros_ec_debugfs *debug_info =69 container_of(to_delayed_work(__work),70 struct cros_ec_debugfs,71 log_poll_work);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,76 };77 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;81 int idx;82 int buf_space;83 int ret;84 85 ret = cros_ec_cmd_xfer_status(ec->ec_dev, &snapshot_msg);86 if (ret < 0)87 goto resched;88 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);92 93 while (1) {94 if (!buf_space) {95 dev_info_once(ec->dev,96 "Some logs may have been dropped...\n");97 break;98 }99 100 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);104 if (ret < 0)105 break;106 107 /* If the buffer is empty, we're done here. */108 if (ret == 0 || ec_buffer[0] == '\0')109 break;110 111 idx = 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);115 idx++;116 buf_space--;117 }118 119 wake_up(&cros_ec_debugfs_log_wq);120 }121 122 mutex_unlock(&debug_info->log_mutex);123 124resched:125 schedule_delayed_work(&debug_info->log_poll_work,126 msecs_to_jiffies(log_poll_period_ms));127}128 129static int cros_ec_console_log_open(struct inode *inode, struct file *file)130{131 file->private_data = inode->i_private;132 133 return stream_open(inode, file);134}135 136static ssize_t cros_ec_console_log_read(struct file *file, char __user *buf,137 size_t count, loff_t *ppos)138{139 struct cros_ec_debugfs *debug_info = file->private_data;140 struct circ_buf *cb = &debug_info->log_buffer;141 ssize_t ret;142 143 mutex_lock(&debug_info->log_mutex);144 145 while (!CIRC_CNT(cb->head, cb->tail, LOG_SIZE)) {146 if (file->f_flags & O_NONBLOCK) {147 ret = -EAGAIN;148 goto error;149 }150 151 mutex_unlock(&debug_info->log_mutex);152 153 ret = wait_event_interruptible(cros_ec_debugfs_log_wq,154 CIRC_CNT(cb->head, cb->tail, LOG_SIZE));155 if (ret < 0)156 return ret;157 158 mutex_lock(&debug_info->log_mutex);159 }160 161 /* Only copy until the end of the circular buffer, and let userspace162 * retry to get the rest of the data.163 */164 ret = min_t(size_t, CIRC_CNT_TO_END(cb->head, cb->tail, LOG_SIZE),165 count);166 167 if (copy_to_user(buf, cb->buf + cb->tail, ret)) {168 ret = -EFAULT;169 goto error;170 }171 172 cb->tail = CIRC_ADD(cb->tail, LOG_SIZE, ret);173 174error:175 mutex_unlock(&debug_info->log_mutex);176 return ret;177}178 179static __poll_t cros_ec_console_log_poll(struct file *file,180 poll_table *wait)181{182 struct cros_ec_debugfs *debug_info = file->private_data;183 __poll_t mask = 0;184 185 poll_wait(file, &cros_ec_debugfs_log_wq, wait);186 187 mutex_lock(&debug_info->log_mutex);188 if (CIRC_CNT(debug_info->log_buffer.head,189 debug_info->log_buffer.tail,190 LOG_SIZE))191 mask |= EPOLLIN | EPOLLRDNORM;192 mutex_unlock(&debug_info->log_mutex);193 194 return mask;195}196 197static int cros_ec_console_log_release(struct inode *inode, struct file *file)198{199 return 0;200}201 202static ssize_t cros_ec_pdinfo_read(struct file *file,203 char __user *user_buf,204 size_t count,205 loff_t *ppos)206{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;210 struct {211 struct cros_ec_command msg;212 union {213 struct ec_response_usb_pd_control_v1 resp;214 struct ec_params_usb_pd_control params;215 };216 } __packed ec_buf;217 struct cros_ec_command *msg;218 struct ec_response_usb_pd_control_v1 *resp;219 struct ec_params_usb_pd_control *params;220 int i;221 222 msg = &ec_buf.msg;223 params = (struct ec_params_usb_pd_control *)msg->data;224 resp = (struct ec_response_usb_pd_control_v1 *)msg->data;225 226 msg->command = EC_CMD_USB_PD_CONTROL;227 msg->version = 1;228 msg->insize = sizeof(*resp);229 msg->outsize = sizeof(*params);230 231 /*232 * Read status from all PD ports until failure, typically caused233 * by attempting to read status on a port that doesn't exist.234 */235 for (i = 0; i < EC_USB_PD_MAX_PORTS; ++i) {236 params->port = i;237 params->role = 0;238 params->mux = 0;239 params->swap = 0;240 241 if (cros_ec_cmd_xfer_status(ec_dev, msg) < 0)242 break;243 244 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,247 resp->polarity);248 }249 250 return simple_read_from_buffer(user_buf, count, ppos,251 read_buf, p - read_buf);252}253 254static bool cros_ec_uptime_is_supported(struct cros_ec_device *ec_dev)255{256 struct {257 struct cros_ec_command cmd;258 struct ec_response_uptime_info resp;259 } __packed msg = {};260 int ret;261 262 msg.cmd.command = EC_CMD_GET_UPTIME_INFO;263 msg.cmd.insize = sizeof(msg.resp);264 265 ret = cros_ec_cmd_xfer_status(ec_dev, &msg.cmd);266 if (ret == -EPROTO && msg.cmd.result == EC_RES_INVALID_COMMAND)267 return false;268 269 /* Other errors maybe a transient error, do not rule about support. */270 return true;271}272 273static ssize_t cros_ec_uptime_read(struct file *file, char __user *user_buf,274 size_t count, loff_t *ppos)275{276 struct cros_ec_debugfs *debug_info = file->private_data;277 struct cros_ec_device *ec_dev = debug_info->ec->ec_dev;278 struct {279 struct cros_ec_command cmd;280 struct ec_response_uptime_info resp;281 } __packed msg = {};282 struct ec_response_uptime_info *resp;283 char read_buf[32];284 int ret;285 286 resp = (struct ec_response_uptime_info *)&msg.resp;287 288 msg.cmd.command = EC_CMD_GET_UPTIME_INFO;289 msg.cmd.insize = sizeof(*resp);290 291 ret = cros_ec_cmd_xfer_status(ec_dev, &msg.cmd);292 if (ret < 0)293 return ret;294 295 ret = scnprintf(read_buf, sizeof(read_buf), "%u\n",296 resp->time_since_ec_boot_ms);297 298 return simple_read_from_buffer(user_buf, count, ppos, read_buf, ret);299}300 301static 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,305 .poll = cros_ec_console_log_poll,306 .release = cros_ec_console_log_release,307};308 309static const struct file_operations cros_ec_pdinfo_fops = {310 .owner = THIS_MODULE,311 .open = simple_open,312 .read = cros_ec_pdinfo_read,313 .llseek = default_llseek,314};315 316static const struct file_operations cros_ec_uptime_fops = {317 .owner = THIS_MODULE,318 .open = simple_open,319 .read = cros_ec_uptime_read,320 .llseek = default_llseek,321};322 323static int ec_read_version_supported(struct cros_ec_dev *ec)324{325 struct ec_params_get_cmd_versions_v1 *params;326 struct ec_response_get_cmd_versions *response;327 int ret;328 329 struct cros_ec_command *msg;330 331 msg = kzalloc(sizeof(*msg) + max(sizeof(*params), sizeof(*response)),332 GFP_KERNEL);333 if (!msg)334 return 0;335 336 msg->version = 1;337 msg->command = EC_CMD_GET_CMD_VERSIONS + ec->cmd_offset;338 msg->outsize = sizeof(*params);339 msg->insize = sizeof(*response);340 341 params = (struct ec_params_get_cmd_versions_v1 *)msg->data;342 params->cmd = EC_CMD_CONSOLE_READ;343 response = (struct ec_response_get_cmd_versions *)msg->data;344 345 ret = cros_ec_cmd_xfer_status(ec->ec_dev, msg) >= 0 &&346 response->version_mask & EC_VER_MASK(1);347 348 kfree(msg);349 350 return ret;351}352 353static int cros_ec_create_console_log(struct cros_ec_debugfs *debug_info)354{355 struct cros_ec_dev *ec = debug_info->ec;356 char *buf;357 int read_params_size;358 int read_response_size;359 360 /*361 * If the console log feature is not supported return silently and362 * don't create the console_log entry.363 */364 if (!ec_read_version_supported(ec))365 return 0;366 367 buf = devm_kzalloc(ec->dev, LOG_SIZE, GFP_KERNEL);368 if (!buf)369 return -ENOMEM;370 371 read_params_size = sizeof(struct ec_params_console_read_v1);372 read_response_size = ec->ec_dev->max_response;373 debug_info->read_msg = devm_kzalloc(ec->dev,374 sizeof(*debug_info->read_msg) +375 max(read_params_size, read_response_size), GFP_KERNEL);376 if (!debug_info->read_msg)377 return -ENOMEM;378 379 debug_info->read_msg->version = 1;380 debug_info->read_msg->command = EC_CMD_CONSOLE_READ + ec->cmd_offset;381 debug_info->read_msg->outsize = read_params_size;382 debug_info->read_msg->insize = read_response_size;383 384 debug_info->log_buffer.buf = buf;385 debug_info->log_buffer.head = 0;386 debug_info->log_buffer.tail = 0;387 388 mutex_init(&debug_info->log_mutex);389 390 debugfs_create_file("console_log", S_IFREG | 0444, debug_info->dir,391 debug_info, &cros_ec_console_log_fops);392 393 INIT_DELAYED_WORK(&debug_info->log_poll_work,394 cros_ec_console_log_work);395 schedule_delayed_work(&debug_info->log_poll_work, 0);396 397 return 0;398}399 400static void cros_ec_cleanup_console_log(struct cros_ec_debugfs *debug_info)401{402 if (debug_info->log_buffer.buf) {403 cancel_delayed_work_sync(&debug_info->log_poll_work);404 mutex_destroy(&debug_info->log_mutex);405 }406}407 408/*409 * Returns the size of the panicinfo data fetched from the EC410 */411static int cros_ec_get_panicinfo(struct cros_ec_device *ec_dev, uint8_t *data,412 int data_size)413{414 int ret;415 struct cros_ec_command *msg;416 417 if (!data || data_size <= 0 || data_size > ec_dev->max_response)418 return -EINVAL;419 420 msg = kzalloc(sizeof(*msg) + data_size, GFP_KERNEL);421 if (!msg)422 return -ENOMEM;423 424 msg->command = EC_CMD_GET_PANIC_INFO;425 msg->insize = data_size;426 427 ret = cros_ec_cmd_xfer_status(ec_dev, msg);428 if (ret < 0)429 goto free;430 431 memcpy(data, msg->data, data_size);432 433free:434 kfree(msg);435 return ret;436}437 438static int cros_ec_create_panicinfo(struct cros_ec_debugfs *debug_info)439{440 struct cros_ec_device *ec_dev = debug_info->ec->ec_dev;441 int ret;442 void *data;443 444 data = devm_kzalloc(debug_info->ec->dev, ec_dev->max_response,445 GFP_KERNEL);446 if (!data)447 return -ENOMEM;448 449 ret = cros_ec_get_panicinfo(ec_dev, data, ec_dev->max_response);450 if (ret < 0) {451 ret = 0;452 goto free;453 }454 455 /* No panic data */456 if (ret == 0)457 goto free;458 459 debug_info->panicinfo_blob.data = data;460 debug_info->panicinfo_blob.size = ret;461 462 debugfs_create_blob("panicinfo", 0444, debug_info->dir,463 &debug_info->panicinfo_blob);464 465 return 0;466 467free:468 devm_kfree(debug_info->ec->dev, data);469 return ret;470}471 472static int cros_ec_debugfs_panic_event(struct notifier_block *nb,473 unsigned long queued_during_suspend, void *_notify)474{475 struct cros_ec_debugfs *debug_info =476 container_of(nb, struct cros_ec_debugfs, notifier_panic);477 478 if (debug_info->log_buffer.buf) {479 /* Force log poll work to run immediately */480 mod_delayed_work(debug_info->log_poll_work.wq, &debug_info->log_poll_work, 0);481 /* Block until log poll work finishes */482 flush_delayed_work(&debug_info->log_poll_work);483 }484 485 return NOTIFY_DONE;486}487 488static int cros_ec_debugfs_probe(struct platform_device *pd)489{490 struct cros_ec_dev *ec = dev_get_drvdata(pd->dev.parent);491 struct cros_ec_platform *ec_platform = dev_get_platdata(ec->dev);492 const char *name = ec_platform->ec_name;493 struct cros_ec_debugfs *debug_info;494 int ret;495 496 debug_info = devm_kzalloc(ec->dev, sizeof(*debug_info), GFP_KERNEL);497 if (!debug_info)498 return -ENOMEM;499 500 debug_info->ec = ec;501 debug_info->dir = debugfs_create_dir(name, NULL);502 503 ret = cros_ec_create_panicinfo(debug_info);504 if (ret)505 goto remove_debugfs;506 507 ret = cros_ec_create_console_log(debug_info);508 if (ret)509 goto remove_debugfs;510 511 debugfs_create_file("pdinfo", 0444, debug_info->dir, debug_info,512 &cros_ec_pdinfo_fops);513 514 if (cros_ec_uptime_is_supported(ec->ec_dev))515 debugfs_create_file("uptime", 0444, debug_info->dir, debug_info,516 &cros_ec_uptime_fops);517 518 debugfs_create_x32("last_resume_result", 0444, debug_info->dir,519 &ec->ec_dev->last_resume_result);520 521 debugfs_create_u16("suspend_timeout_ms", 0664, debug_info->dir,522 &ec->ec_dev->suspend_timeout_ms);523 524 debug_info->notifier_panic.notifier_call = cros_ec_debugfs_panic_event;525 ret = blocking_notifier_chain_register(&ec->ec_dev->panic_notifier,526 &debug_info->notifier_panic);527 if (ret)528 goto remove_debugfs;529 530 ec->debug_info = debug_info;531 532 dev_set_drvdata(&pd->dev, ec);533 534 return 0;535 536remove_debugfs:537 debugfs_remove_recursive(debug_info->dir);538 return ret;539}540 541static void cros_ec_debugfs_remove(struct platform_device *pd)542{543 struct cros_ec_dev *ec = dev_get_drvdata(pd->dev.parent);544 545 debugfs_remove_recursive(ec->debug_info->dir);546 cros_ec_cleanup_console_log(ec->debug_info);547}548 549static int __maybe_unused cros_ec_debugfs_suspend(struct device *dev)550{551 struct cros_ec_dev *ec = dev_get_drvdata(dev);552 553 if (ec->debug_info->log_buffer.buf)554 cancel_delayed_work_sync(&ec->debug_info->log_poll_work);555 556 return 0;557}558 559static int __maybe_unused cros_ec_debugfs_resume(struct device *dev)560{561 struct cros_ec_dev *ec = dev_get_drvdata(dev);562 563 if (ec->debug_info->log_buffer.buf)564 schedule_delayed_work(&ec->debug_info->log_poll_work, 0);565 566 return 0;567}568 569static SIMPLE_DEV_PM_OPS(cros_ec_debugfs_pm_ops,570 cros_ec_debugfs_suspend, cros_ec_debugfs_resume);571 572static const struct platform_device_id cros_ec_debugfs_id[] = {573 { DRV_NAME, 0 },574 {}575};576MODULE_DEVICE_TABLE(platform, cros_ec_debugfs_id);577 578static struct platform_driver cros_ec_debugfs_driver = {579 .driver = {580 .name = DRV_NAME,581 .pm = &cros_ec_debugfs_pm_ops,582 .probe_type = PROBE_PREFER_ASYNCHRONOUS,583 },584 .probe = cros_ec_debugfs_probe,585 .remove_new = cros_ec_debugfs_remove,586 .id_table = cros_ec_debugfs_id,587};588 589module_platform_driver(cros_ec_debugfs_driver);590 591MODULE_LICENSE("GPL");592MODULE_DESCRIPTION("Debug logs for ChromeOS EC");593