[PATCH 04/13] mfd: cros_ec: Add support for dumping panic information

From: Enric Balletbo i Serra
Date: Fri Mar 17 2017 - 10:00:38 EST


From: Nicolas Boichat <drinkcat@xxxxxxxxxxxx>

This dumps the EC panic information from the previous reboot.

Similar to the information presented by ectool panicinfo, except
that we do not bother doing any parsing (we should write a small
offline tool for that).

Signed-off-by: Nicolas Boichat <drinkcat@xxxxxxxxxxxx>
Reviewed-by: Guenter Roeck <groeck@xxxxxxxxxxxx>
Tested-by: Enric Balletbo i Serra <enric.balletbo@xxxxxxxxxxxxx>
---
drivers/platform/chrome/cros_ec_debugfs.c | 54 +++++++++++++++++++++++++++++++
1 file changed, 54 insertions(+)

diff --git a/drivers/platform/chrome/cros_ec_debugfs.c b/drivers/platform/chrome/cros_ec_debugfs.c
index f8195bb..8133c33 100644
--- a/drivers/platform/chrome/cros_ec_debugfs.c
+++ b/drivers/platform/chrome/cros_ec_debugfs.c
@@ -47,15 +47,19 @@
* @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
+ * @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;
wait_queue_head_t log_wq;
struct delayed_work log_poll_work;
+ /* EC panicinfo */
+ struct debugfs_blob_wrapper panicinfo_blob;
};

/*
@@ -308,6 +312,52 @@ static void cros_ec_cleanup_console_log(struct cros_ec_debugfs *debug_info)
}
}

+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(ec_dev, msg);
+ if (ret < 0) {
+ dev_warn(debug_info->ec->dev, "Cannot read panicinfo.\n");
+ 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;
+
+ if (!debugfs_create_blob("panicinfo",
+ S_IFREG | S_IRUGO,
+ debug_info->dir,
+ &debug_info->panicinfo_blob)) {
+ ret = -ENOMEM;
+ goto free;
+ }
+
+ return 0;
+
+free:
+ devm_kfree(debug_info->ec->dev, msg);
+ return ret;
+}
+
int cros_ec_debugfs_init(struct cros_ec_dev *ec)
{
struct cros_ec_platform *ec_platform = dev_get_platdata(ec->dev);
@@ -324,6 +374,10 @@ int cros_ec_debugfs_init(struct cros_ec_dev *ec)
if (!debug_info->dir)
return -ENOMEM;

+ 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;
--
2.9.3