| // SPDX-License-Identifier: GPL-2.0+ |
| // Debug logs for the ChromeOS EC |
| // |
| // Copyright (C) 2015 Google, Inc. |
| |
| #include <linux/circ_buf.h> |
| #include <linux/debugfs.h> |
| #include <linux/delay.h> |
| #include <linux/fs.h> |
| #include <linux/module.h> |
| #include <linux/mutex.h> |
| #include <linux/platform_data/cros_ec_commands.h> |
| #include <linux/platform_data/cros_ec_proto.h> |
| #include <linux/platform_device.h> |
| #include <linux/poll.h> |
| #include <linux/sched.h> |
| #include <linux/slab.h> |
| #include <linux/wait.h> |
| |
| #define DRV_NAME "cros-ec-debugfs" |
| |
| #define LOG_SHIFT 14 |
| #define LOG_SIZE (1 << LOG_SHIFT) |
| #define LOG_POLL_SEC 10 |
| |
| #define CIRC_ADD(idx, size, value) (((idx) + (value)) & ((size) - 1)) |
| |
| /* waitqueue for log readers */ |
| static DECLARE_WAIT_QUEUE_HEAD(cros_ec_debugfs_log_wq); |
| |
| /** |
| * struct cros_ec_debugfs - EC debugging information. |
| * |
| * @ec: EC device this debugfs information belongs to |
| * @dir: dentry for debugfs files |
| * @log_buffer: circular buffer for console log information |
| * @read_msg: preallocated EC command and buffer to read console log |
| * @log_mutex: mutex to protect circular buffer |
| * @log_poll_work: recurring task to poll EC for new console log data |
| * @panicinfo_blob: panicinfo debugfs blob |
| */ |
| struct cros_ec_debugfs { |
| struct cros_ec_dev *ec; |
| struct dentry *dir; |
| /* EC log */ |
| struct circ_buf log_buffer; |
| struct cros_ec_command *read_msg; |
| struct mutex log_mutex; |
| struct delayed_work log_poll_work; |
| /* EC panicinfo */ |
| struct debugfs_blob_wrapper panicinfo_blob; |
| }; |
| |
| /* |
| * We need to make sure that the EC log buffer on the UART is large enough, |
| * so that it is unlikely enough to overlow within LOG_POLL_SEC. |
| */ |
| static void cros_ec_console_log_work(struct work_struct *__work) |
| { |
| struct cros_ec_debugfs *debug_info = |
| container_of(to_delayed_work(__work), |
| struct cros_ec_debugfs, |
| log_poll_work); |
| struct cros_ec_dev *ec = debug_info->ec; |
| struct circ_buf *cb = &debug_info->log_buffer; |
| struct cros_ec_command snapshot_msg = { |
| .command = EC_CMD_CONSOLE_SNAPSHOT + ec->cmd_offset, |
| }; |
| |
| struct ec_params_console_read_v1 *read_params = |
| (struct ec_params_console_read_v1 *)debug_info->read_msg->data; |
| uint8_t *ec_buffer = (uint8_t *)debug_info->read_msg->data; |
| int idx; |
| int buf_space; |
| int ret; |
| |
| ret = cros_ec_cmd_xfer_status(ec->ec_dev, &snapshot_msg); |
| if (ret < 0) |
| goto resched; |
| |
| /* Loop until we have read everything, or there's an error. */ |
| mutex_lock(&debug_info->log_mutex); |
| buf_space = CIRC_SPACE(cb->head, cb->tail, LOG_SIZE); |
| |
| while (1) { |
| if (!buf_space) { |
| dev_info_once(ec->dev, |
| "Some logs may have been dropped...\n"); |
| break; |
| } |
| |
| memset(read_params, '\0', sizeof(*read_params)); |
| read_params->subcmd = CONSOLE_READ_RECENT; |
| ret = cros_ec_cmd_xfer_status(ec->ec_dev, |
| debug_info->read_msg); |
| if (ret < 0) |
| break; |
| |
| /* If the buffer is empty, we're done here. */ |
| if (ret == 0 || ec_buffer[0] == '\0') |
| break; |
| |
| idx = 0; |
| while (idx < ret && ec_buffer[idx] != '\0' && buf_space > 0) { |
| cb->buf[cb->head] = ec_buffer[idx]; |
| cb->head = CIRC_ADD(cb->head, LOG_SIZE, 1); |
| idx++; |
| buf_space--; |
| } |
| |
| wake_up(&cros_ec_debugfs_log_wq); |
| } |
| |
| mutex_unlock(&debug_info->log_mutex); |
| |
| resched: |
| schedule_delayed_work(&debug_info->log_poll_work, |
| msecs_to_jiffies(LOG_POLL_SEC * 1000)); |
| } |
| |
| static int cros_ec_console_log_open(struct inode *inode, struct file *file) |
| { |
| file->private_data = inode->i_private; |
| |
| return stream_open(inode, file); |
| } |
| |
| static ssize_t cros_ec_console_log_read(struct file *file, char __user *buf, |
| size_t count, loff_t *ppos) |
| { |
| struct cros_ec_debugfs *debug_info = file->private_data; |
| struct circ_buf *cb = &debug_info->log_buffer; |
| ssize_t ret; |
| |
| mutex_lock(&debug_info->log_mutex); |
| |
| while (!CIRC_CNT(cb->head, cb->tail, LOG_SIZE)) { |
| if (file->f_flags & O_NONBLOCK) { |
| ret = -EAGAIN; |
| goto error; |
| } |
| |
| mutex_unlock(&debug_info->log_mutex); |
| |
| ret = wait_event_interruptible(cros_ec_debugfs_log_wq, |
| CIRC_CNT(cb->head, cb->tail, LOG_SIZE)); |
| if (ret < 0) |
| return ret; |
| |
| mutex_lock(&debug_info->log_mutex); |
| } |
| |
| /* Only copy until the end of the circular buffer, and let userspace |
| * retry to get the rest of the data. |
| */ |
| ret = min_t(size_t, CIRC_CNT_TO_END(cb->head, cb->tail, LOG_SIZE), |
| count); |
| |
| if (copy_to_user(buf, cb->buf + cb->tail, ret)) { |
| ret = -EFAULT; |
| goto error; |
| } |
| |
| cb->tail = CIRC_ADD(cb->tail, LOG_SIZE, ret); |
| |
| error: |
| mutex_unlock(&debug_info->log_mutex); |
| return ret; |
| } |
| |
| static __poll_t cros_ec_console_log_poll(struct file *file, |
| poll_table *wait) |
| { |
| struct cros_ec_debugfs *debug_info = file->private_data; |
| __poll_t mask = 0; |
| |
| poll_wait(file, &cros_ec_debugfs_log_wq, wait); |
| |
| mutex_lock(&debug_info->log_mutex); |
| if (CIRC_CNT(debug_info->log_buffer.head, |
| debug_info->log_buffer.tail, |
| LOG_SIZE)) |
| mask |= EPOLLIN | EPOLLRDNORM; |
| mutex_unlock(&debug_info->log_mutex); |
| |
| return mask; |
| } |
| |
| static int cros_ec_console_log_release(struct inode *inode, struct file *file) |
| { |
| return 0; |
| } |
| |
| static ssize_t cros_ec_pdinfo_read(struct file *file, |
| char __user *user_buf, |
| size_t count, |
| loff_t *ppos) |
| { |
| char read_buf[EC_USB_PD_MAX_PORTS * 40], *p = read_buf; |
| struct cros_ec_debugfs *debug_info = file->private_data; |
| struct cros_ec_device *ec_dev = debug_info->ec->ec_dev; |
| struct { |
| struct cros_ec_command msg; |
| union { |
| struct ec_response_usb_pd_control_v1 resp; |
| struct ec_params_usb_pd_control params; |
| }; |
| } __packed ec_buf; |
| struct cros_ec_command *msg; |
| struct ec_response_usb_pd_control_v1 *resp; |
| struct ec_params_usb_pd_control *params; |
| int i; |
| |
| msg = &ec_buf.msg; |
| params = (struct ec_params_usb_pd_control *)msg->data; |
| resp = (struct ec_response_usb_pd_control_v1 *)msg->data; |
| |
| msg->command = EC_CMD_USB_PD_CONTROL; |
| msg->version = 1; |
| msg->insize = sizeof(*resp); |
| msg->outsize = sizeof(*params); |
| |
| /* |
| * Read status from all PD ports until failure, typically caused |
| * by attempting to read status on a port that doesn't exist. |
| */ |
| for (i = 0; i < EC_USB_PD_MAX_PORTS; ++i) { |
| params->port = i; |
| params->role = 0; |
| params->mux = 0; |
| params->swap = 0; |
| |
| if (cros_ec_cmd_xfer_status(ec_dev, msg) < 0) |
| break; |
| |
| p += scnprintf(p, sizeof(read_buf) + read_buf - p, |
| "p%d: %s en:%.2x role:%.2x pol:%.2x\n", i, |
| resp->state, resp->enabled, resp->role, |
| resp->polarity); |
| } |
| |
| return simple_read_from_buffer(user_buf, count, ppos, |
| read_buf, p - read_buf); |
| } |
| |
| static bool cros_ec_uptime_is_supported(struct cros_ec_device *ec_dev) |
| { |
| struct { |
| struct cros_ec_command cmd; |
| struct ec_response_uptime_info resp; |
| } __packed msg = {}; |
| int ret; |
| |
| msg.cmd.command = EC_CMD_GET_UPTIME_INFO; |
| msg.cmd.insize = sizeof(msg.resp); |
| |
| ret = cros_ec_cmd_xfer_status(ec_dev, &msg.cmd); |
| if (ret == -EPROTO && msg.cmd.result == EC_RES_INVALID_COMMAND) |
| return false; |
| |
| /* Other errors maybe a transient error, do not rule about support. */ |
| return true; |
| } |
| |
| static ssize_t cros_ec_uptime_read(struct file *file, char __user *user_buf, |
| size_t count, loff_t *ppos) |
| { |
| struct cros_ec_debugfs *debug_info = file->private_data; |
| struct cros_ec_device *ec_dev = debug_info->ec->ec_dev; |
| struct { |
| struct cros_ec_command cmd; |
| struct ec_response_uptime_info resp; |
| } __packed msg = {}; |
| struct ec_response_uptime_info *resp; |
| char read_buf[32]; |
| int ret; |
| |
| resp = (struct ec_response_uptime_info *)&msg.resp; |
| |
| msg.cmd.command = EC_CMD_GET_UPTIME_INFO; |
| msg.cmd.insize = sizeof(*resp); |
| |
| ret = cros_ec_cmd_xfer_status(ec_dev, &msg.cmd); |
| if (ret < 0) |
| return ret; |
| |
| ret = scnprintf(read_buf, sizeof(read_buf), "%u\n", |
| resp->time_since_ec_boot_ms); |
| |
| return simple_read_from_buffer(user_buf, count, ppos, read_buf, ret); |
| } |
| |
| static const struct file_operations cros_ec_console_log_fops = { |
| .owner = THIS_MODULE, |
| .open = cros_ec_console_log_open, |
| .read = cros_ec_console_log_read, |
| .llseek = no_llseek, |
| .poll = cros_ec_console_log_poll, |
| .release = cros_ec_console_log_release, |
| }; |
| |
| static const struct file_operations cros_ec_pdinfo_fops = { |
| .owner = THIS_MODULE, |
| .open = simple_open, |
| .read = cros_ec_pdinfo_read, |
| .llseek = default_llseek, |
| }; |
| |
| static const struct file_operations cros_ec_uptime_fops = { |
| .owner = THIS_MODULE, |
| .open = simple_open, |
| .read = cros_ec_uptime_read, |
| .llseek = default_llseek, |
| }; |
| |
| static int ec_read_version_supported(struct cros_ec_dev *ec) |
| { |
| struct ec_params_get_cmd_versions_v1 *params; |
| struct ec_response_get_cmd_versions *response; |
| int ret; |
| |
| struct cros_ec_command *msg; |
| |
| msg = kzalloc(sizeof(*msg) + max(sizeof(*params), sizeof(*response)), |
| GFP_KERNEL); |
| if (!msg) |
| return 0; |
| |
| msg->command = EC_CMD_GET_CMD_VERSIONS + ec->cmd_offset; |
| msg->outsize = sizeof(*params); |
| msg->insize = sizeof(*response); |
| |
| params = (struct ec_params_get_cmd_versions_v1 *)msg->data; |
| params->cmd = EC_CMD_CONSOLE_READ; |
| response = (struct ec_response_get_cmd_versions *)msg->data; |
| |
| ret = cros_ec_cmd_xfer_status(ec->ec_dev, msg) >= 0 && |
| response->version_mask & EC_VER_MASK(1); |
| |
| kfree(msg); |
| |
| return ret; |
| } |
| |
| static int cros_ec_create_console_log(struct cros_ec_debugfs *debug_info) |
| { |
| struct cros_ec_dev *ec = debug_info->ec; |
| char *buf; |
| int read_params_size; |
| int read_response_size; |
| |
| /* |
| * If the console log feature is not supported return silently and |
| * don't create the console_log entry. |
| */ |
| if (!ec_read_version_supported(ec)) |
| return 0; |
| |
| buf = devm_kzalloc(ec->dev, LOG_SIZE, GFP_KERNEL); |
| if (!buf) |
| return -ENOMEM; |
| |
| read_params_size = sizeof(struct ec_params_console_read_v1); |
| read_response_size = ec->ec_dev->max_response; |
| debug_info->read_msg = devm_kzalloc(ec->dev, |
| sizeof(*debug_info->read_msg) + |
| max(read_params_size, read_response_size), GFP_KERNEL); |
| if (!debug_info->read_msg) |
| return -ENOMEM; |
| |
| debug_info->read_msg->version = 1; |
| debug_info->read_msg->command = EC_CMD_CONSOLE_READ + ec->cmd_offset; |
| debug_info->read_msg->outsize = read_params_size; |
| debug_info->read_msg->insize = read_response_size; |
| |
| debug_info->log_buffer.buf = buf; |
| debug_info->log_buffer.head = 0; |
| debug_info->log_buffer.tail = 0; |
| |
| mutex_init(&debug_info->log_mutex); |
| |
| debugfs_create_file("console_log", S_IFREG | 0444, debug_info->dir, |
| debug_info, &cros_ec_console_log_fops); |
| |
| INIT_DELAYED_WORK(&debug_info->log_poll_work, |
| cros_ec_console_log_work); |
| schedule_delayed_work(&debug_info->log_poll_work, 0); |
| |
| return 0; |
| } |
| |
| static void cros_ec_cleanup_console_log(struct cros_ec_debugfs *debug_info) |
| { |
| if (debug_info->log_buffer.buf) { |
| cancel_delayed_work_sync(&debug_info->log_poll_work); |
| mutex_destroy(&debug_info->log_mutex); |
| } |
| } |
| |
| static int cros_ec_create_panicinfo(struct cros_ec_debugfs *debug_info) |
| { |
| struct cros_ec_device *ec_dev = debug_info->ec->ec_dev; |
| int ret; |
| struct cros_ec_command *msg; |
| int insize; |
| |
| insize = ec_dev->max_response; |
| |
| msg = devm_kzalloc(debug_info->ec->dev, |
| sizeof(*msg) + insize, GFP_KERNEL); |
| if (!msg) |
| return -ENOMEM; |
| |
| msg->command = EC_CMD_GET_PANIC_INFO; |
| msg->insize = insize; |
| |
| ret = cros_ec_cmd_xfer_status(ec_dev, msg); |
| if (ret < 0) { |
| ret = 0; |
| goto free; |
| } |
| |
| /* No panic data */ |
| if (ret == 0) |
| goto free; |
| |
| debug_info->panicinfo_blob.data = msg->data; |
| debug_info->panicinfo_blob.size = ret; |
| |
| debugfs_create_blob("panicinfo", S_IFREG | 0444, debug_info->dir, |
| &debug_info->panicinfo_blob); |
| |
| return 0; |
| |
| free: |
| devm_kfree(debug_info->ec->dev, msg); |
| return ret; |
| } |
| |
| static int cros_ec_debugfs_probe(struct platform_device *pd) |
| { |
| struct cros_ec_dev *ec = dev_get_drvdata(pd->dev.parent); |
| struct cros_ec_platform *ec_platform = dev_get_platdata(ec->dev); |
| const char *name = ec_platform->ec_name; |
| struct cros_ec_debugfs *debug_info; |
| int ret; |
| |
| debug_info = devm_kzalloc(ec->dev, sizeof(*debug_info), GFP_KERNEL); |
| if (!debug_info) |
| return -ENOMEM; |
| |
| debug_info->ec = ec; |
| debug_info->dir = debugfs_create_dir(name, NULL); |
| |
| ret = cros_ec_create_panicinfo(debug_info); |
| if (ret) |
| goto remove_debugfs; |
| |
| ret = cros_ec_create_console_log(debug_info); |
| if (ret) |
| goto remove_debugfs; |
| |
| debugfs_create_file("pdinfo", 0444, debug_info->dir, debug_info, |
| &cros_ec_pdinfo_fops); |
| |
| if (cros_ec_uptime_is_supported(ec->ec_dev)) |
| debugfs_create_file("uptime", 0444, debug_info->dir, debug_info, |
| &cros_ec_uptime_fops); |
| |
| debugfs_create_x32("last_resume_result", 0444, debug_info->dir, |
| &ec->ec_dev->last_resume_result); |
| |
| ec->debug_info = debug_info; |
| |
| dev_set_drvdata(&pd->dev, ec); |
| |
| return 0; |
| |
| remove_debugfs: |
| debugfs_remove_recursive(debug_info->dir); |
| return ret; |
| } |
| |
| static int cros_ec_debugfs_remove(struct platform_device *pd) |
| { |
| struct cros_ec_dev *ec = dev_get_drvdata(pd->dev.parent); |
| |
| debugfs_remove_recursive(ec->debug_info->dir); |
| cros_ec_cleanup_console_log(ec->debug_info); |
| |
| return 0; |
| } |
| |
| static int __maybe_unused cros_ec_debugfs_suspend(struct device *dev) |
| { |
| struct cros_ec_dev *ec = dev_get_drvdata(dev); |
| |
| if (ec->debug_info->log_buffer.buf) |
| cancel_delayed_work_sync(&ec->debug_info->log_poll_work); |
| |
| return 0; |
| } |
| |
| static int __maybe_unused cros_ec_debugfs_resume(struct device *dev) |
| { |
| struct cros_ec_dev *ec = dev_get_drvdata(dev); |
| |
| if (ec->debug_info->log_buffer.buf) |
| schedule_delayed_work(&ec->debug_info->log_poll_work, 0); |
| |
| return 0; |
| } |
| |
| static SIMPLE_DEV_PM_OPS(cros_ec_debugfs_pm_ops, |
| cros_ec_debugfs_suspend, cros_ec_debugfs_resume); |
| |
| static struct platform_driver cros_ec_debugfs_driver = { |
| .driver = { |
| .name = DRV_NAME, |
| .pm = &cros_ec_debugfs_pm_ops, |
| }, |
| .probe = cros_ec_debugfs_probe, |
| .remove = cros_ec_debugfs_remove, |
| }; |
| |
| module_platform_driver(cros_ec_debugfs_driver); |
| |
| MODULE_LICENSE("GPL"); |
| MODULE_DESCRIPTION("Debug logs for ChromeOS EC"); |
| MODULE_ALIAS("platform:" DRV_NAME); |