diff options
| -rw-r--r-- | drivers/platform/chrome/Makefile | 3 | ||||
| -rw-r--r-- | drivers/platform/chrome/cros_ec_debugfs.c | 347 | ||||
| -rw-r--r-- | drivers/platform/chrome/cros_ec_debugfs.h | 27 | ||||
| -rw-r--r-- | drivers/platform/chrome/cros_ec_dev.c | 7 | ||||
| -rw-r--r-- | include/linux/mfd/cros_ec.h | 4 |
5 files changed, 387 insertions, 1 deletions
diff --git a/drivers/platform/chrome/Makefile b/drivers/platform/chrome/Makefile index 4f3462783a3c..3870afeefcf4 100644 --- a/drivers/platform/chrome/Makefile +++ b/drivers/platform/chrome/Makefile @@ -2,7 +2,8 @@ obj-$(CONFIG_CHROMEOS_LAPTOP) += chromeos_laptop.o obj-$(CONFIG_CHROMEOS_PSTORE) += chromeos_pstore.o cros_ec_devs-objs := cros_ec_dev.o cros_ec_sysfs.o \ - cros_ec_lightbar.o cros_ec_vbc.o + cros_ec_lightbar.o cros_ec_vbc.o \ + cros_ec_debugfs.o obj-$(CONFIG_CROS_EC_CHARDEV) += cros_ec_devs.o obj-$(CONFIG_CROS_EC_LPC) += cros_ec_lpc.o obj-$(CONFIG_CROS_EC_PROTO) += cros_ec_proto.o diff --git a/drivers/platform/chrome/cros_ec_debugfs.c b/drivers/platform/chrome/cros_ec_debugfs.c new file mode 100644 index 000000000000..225f93631051 --- /dev/null +++ b/drivers/platform/chrome/cros_ec_debugfs.c @@ -0,0 +1,347 @@ +/* + * cros_ec_debugfs - debug logs for Chrome OS EC + * + * Copyright 2015 Google, Inc. + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program. If not, see <http://www.gnu.org/licenses/>. + */ + +#include <linux/circ_buf.h> +#include <linux/debugfs.h> +#include <linux/delay.h> +#include <linux/fs.h> +#include <linux/mfd/cros_ec.h> +#include <linux/mfd/cros_ec_commands.h> +#include <linux/mutex.h> +#include <linux/poll.h> +#include <linux/sched.h> +#include <linux/slab.h> +#include <linux/wait.h> + +#include "cros_ec_dev.h" +#include "cros_ec_debugfs.h" + +#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)) + +/* struct cros_ec_debugfs - ChromeOS 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_wq: waitqueue for log readers + * @log_poll_work: recurring task to poll EC for new console log data + */ +struct cros_ec_debugfs { + struct cros_ec_dev *ec; + struct dentry *dir; + struct circ_buf log_buffer; + struct cros_ec_command *read_msg; + struct mutex log_mutex; + wait_queue_head_t log_wq; + struct delayed_work log_poll_work; +}; + +/* + * 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(ec->ec_dev, &snapshot_msg); + if (ret < 0) { + dev_err(ec->dev, "EC communication failed\n"); + goto resched; + } + if (snapshot_msg.result != EC_RES_SUCCESS) { + dev_err(ec->dev, "EC failed to snapshot the console log\n"); + 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(ec->ec_dev, debug_info->read_msg); + if (ret < 0) { + dev_err(ec->dev, "EC communication failed\n"); + break; + } + if (debug_info->read_msg->result != EC_RES_SUCCESS) { + dev_err(ec->dev, + "EC failed to read the console log\n"); + 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(&debug_info->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 nonseekable_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(debug_info->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 unsigned int cros_ec_console_log_poll(struct file *file, + poll_table *wait) +{ + struct cros_ec_debugfs *debug_info = file->private_data; + unsigned int mask = 0; + + poll_wait(file, &debug_info->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 |= POLLIN | POLLRDNORM; + mutex_unlock(&debug_info->log_mutex); + + return mask; +} + +static int cros_ec_console_log_release(struct inode *inode, struct file *file) +{ + return 0; +} + +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 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(ec->ec_dev, msg) >= 0 && + msg->result == EC_RES_SUCCESS && + (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 (!ec_read_version_supported(ec)) { + dev_warn(ec->dev, + "device does not support reading the console log\n"); + 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); + init_waitqueue_head(&debug_info->log_wq); + + if (!debugfs_create_file("console_log", + S_IFREG | S_IRUGO, + debug_info->dir, + debug_info, + &cros_ec_console_log_fops)) + return -ENOMEM; + + 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); + } +} + +int cros_ec_debugfs_init(struct cros_ec_dev *ec) +{ + 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); + if (!debug_info->dir) + return -ENOMEM; + + ret = cros_ec_create_console_log(debug_info); + if (ret) + goto remove_debugfs; + + ec->debug_info = debug_info; + + return 0; + +remove_debugfs: + debugfs_remove_recursive(debug_info->dir); + return ret; +} + +void cros_ec_debugfs_remove(struct cros_ec_dev *ec) +{ + if (!ec->debug_info) + return; + + debugfs_remove_recursive(ec->debug_info->dir); + cros_ec_cleanup_console_log(ec->debug_info); +} diff --git a/drivers/platform/chrome/cros_ec_debugfs.h b/drivers/platform/chrome/cros_ec_debugfs.h new file mode 100644 index 000000000000..1ff3a50aa1b8 --- /dev/null +++ b/drivers/platform/chrome/cros_ec_debugfs.h @@ -0,0 +1,27 @@ +/* + * Copyright 2015 Google, Inc. + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program. If not, see <http://www.gnu.org/licenses/>. + */ + +#ifndef _DRV_CROS_EC_DEBUGFS_H_ +#define _DRV_CROS_EC_DEBUGFS_H_ + +#include "cros_ec_dev.h" + +/* debugfs stuff */ +int cros_ec_debugfs_init(struct cros_ec_dev *ec); +void cros_ec_debugfs_remove(struct cros_ec_dev *ec); + +#endif /* _DRV_CROS_EC_DEBUGFS_H_ */ diff --git a/drivers/platform/chrome/cros_ec_dev.c b/drivers/platform/chrome/cros_ec_dev.c index 6aa120cd0574..20ce1c23fb5c 100644 --- a/drivers/platform/chrome/cros_ec_dev.c +++ b/drivers/platform/chrome/cros_ec_dev.c @@ -24,6 +24,7 @@ #include <linux/slab.h> #include <linux/uaccess.h> +#include "cros_ec_debugfs.h" #include "cros_ec_dev.h" /* Device variables */ @@ -427,6 +428,9 @@ static int ec_device_probe(struct platform_device *pdev) goto failed; } + if (cros_ec_debugfs_init(ec)) + dev_warn(dev, "failed to create debugfs directory\n"); + /* check whether this EC is a sensor hub. */ if (cros_ec_check_features(ec, EC_FEATURE_MOTION_SENSE)) cros_ec_sensors_register(ec); @@ -441,6 +445,9 @@ failed: static int ec_device_remove(struct platform_device *pdev) { struct cros_ec_dev *ec = dev_get_drvdata(&pdev->dev); + + cros_ec_debugfs_remove(ec); + cdev_del(&ec->cdev); device_unregister(&ec->class_dev); return 0; diff --git a/include/linux/mfd/cros_ec.h b/include/linux/mfd/cros_ec.h index b61b2e013698..3b16c9009749 100644 --- a/include/linux/mfd/cros_ec.h +++ b/include/linux/mfd/cros_ec.h @@ -172,6 +172,8 @@ struct cros_ec_platform { u16 cmd_offset; }; +struct cros_ec_debugfs; + /* * struct cros_ec_dev - ChromeOS EC device entry point * @@ -179,6 +181,7 @@ struct cros_ec_platform { * @cdev: Character device structure in /dev * @ec_dev: cros_ec_device structure to talk to the physical device * @dev: pointer to the platform device + * @debug_info: cros_ec_debugfs structure for debugging information * @cmd_offset: offset to apply for each command. */ struct cros_ec_dev { @@ -186,6 +189,7 @@ struct cros_ec_dev { struct cdev cdev; struct cros_ec_device *ec_dev; struct device *dev; + struct cros_ec_debugfs *debug_info; u16 cmd_offset; u32 features[2]; }; |