1 files changed, 583 insertions, 0 deletions

diff --git a/drivers/platform/chrome/cros_ec_debugfs.c b/drivers/platform/chrome/cros_ec_debugfs.c
new file mode 100644
index 0000000000..c876120e0e
--- /dev/null
+++ b/drivers/platform/chrome/cros_ec_debugfs.c
@@ -0,0 +1,583 @@
+// 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
+ * @notifier_panic: notifier_block to let kernel to flush buffered log
+ *                  when EC panic
+ */
+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;
+	struct notifier_block notifier_panic;
+};
+
+/*
+ * 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);
+	}
+}
+
+/*
+ * Returns the size of the panicinfo data fetched from the EC
+ */
+static int cros_ec_get_panicinfo(struct cros_ec_device *ec_dev, uint8_t *data,
+				 int data_size)
+{
+	int ret;
+	struct cros_ec_command *msg;
+
+	if (!data || data_size <= 0 || data_size > ec_dev->max_response)
+		return -EINVAL;
+
+	msg = kzalloc(sizeof(*msg) + data_size, GFP_KERNEL);
+	if (!msg)
+		return -ENOMEM;
+
+	msg->command = EC_CMD_GET_PANIC_INFO;
+	msg->insize = data_size;
+
+	ret = cros_ec_cmd_xfer_status(ec_dev, msg);
+	if (ret < 0)
+		goto free;
+
+	memcpy(data, msg->data, data_size);
+
+free:
+	kfree(msg);
+	return ret;
+}
+
+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;
+	void *data;
+
+	data = devm_kzalloc(debug_info->ec->dev, ec_dev->max_response,
+			    GFP_KERNEL);
+	if (!data)
+		return -ENOMEM;
+
+	ret = cros_ec_get_panicinfo(ec_dev, data, ec_dev->max_response);
+	if (ret < 0) {
+		ret = 0;
+		goto free;
+	}
+
+	/* No panic data */
+	if (ret == 0)
+		goto free;
+
+	debug_info->panicinfo_blob.data = 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, data);
+	return ret;
+}
+
+static int cros_ec_debugfs_panic_event(struct notifier_block *nb,
+				       unsigned long queued_during_suspend, void *_notify)
+{
+	struct cros_ec_debugfs *debug_info =
+		container_of(nb, struct cros_ec_debugfs, notifier_panic);
+
+	if (debug_info->log_buffer.buf) {
+		/* Force log poll work to run immediately */
+		mod_delayed_work(debug_info->log_poll_work.wq, &debug_info->log_poll_work, 0);
+		/* Block until log poll work finishes */
+		flush_delayed_work(&debug_info->log_poll_work);
+	}
+
+	return NOTIFY_DONE;
+}
+
+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);
+
+	debugfs_create_u16("suspend_timeout_ms", 0664, debug_info->dir,
+			   &ec->ec_dev->suspend_timeout_ms);
+
+	debug_info->notifier_panic.notifier_call = cros_ec_debugfs_panic_event;
+	ret = blocking_notifier_chain_register(&ec->ec_dev->panic_notifier,
+					       &debug_info->notifier_panic);
+	if (ret)
+		goto remove_debugfs;
+
+	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_type = PROBE_PREFER_ASYNCHRONOUS,
+	},
+	.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);