[PATCH] platform/chrome: cros_ec: Report EC panic as uevent

[Rob Barnes <robbarnes@google.com>]

Create a uevent when an EC panic is detected. This will allow udev rules
to trigger when a panic occurs. E.g. a udev rule could be added to
create an EC coredump. This approach allows more code to be moved out
of the kernel drivers.

Change-Id: I4fe7e4e603dcbf0ae6d4c4506f8978b0486abbbf
Signed-off-by: Rob Barnes <robbarnes@google.com>
---
 drivers/platform/chrome/cros_ec_lpc.c | 20 ++++++++++++++++++++
 1 file changed, 20 insertions(+)

diff --git a/drivers/platform/chrome/cros_ec_lpc.c b/drivers/platform/chrome/cros_ec_lpc.c
index b399f7cbf17be..f2d5b00e6c3a0 100644
--- a/drivers/platform/chrome/cros_ec_lpc.c
+++ b/drivers/platform/chrome/cros_ec_lpc.c
@@ -16,6 +16,7 @@
 #include <linux/delay.h>
 #include <linux/io.h>
 #include <linux/interrupt.h>
+#include <linux/kobject.h>
 #include <linux/module.h>
 #include <linux/platform_data/cros_ec_commands.h>
 #include <linux/platform_data/cros_ec_proto.h>
@@ -313,6 +314,23 @@ static int cros_ec_lpc_readmem(struct cros_ec_device *ec, unsigned int offset,
 	return cnt;
 }
 
+/**
+ * cros_ec_lpc_panic_uevent() - Publish EC panic uevent
+ * @ec_dev: Device that panic'd
+ *
+ * This function will generate a uevent to notify userspace.
+ * Typically the system will be reset shortly after an EC panic occurs.
+ *
+ * Return: 0 on success or <0 on error.
+ */
+static int cros_ec_lpc_panic_uevent(struct cros_ec_device *ec_dev)
+{
+	struct device *dev = ec_dev->dev;
+	static char *env[] = { "ERROR=PANIC", NULL };
+
+	return kobject_uevent_env(&dev->kobj, KOBJ_CHANGE, env);
+}
+
 static void cros_ec_lpc_acpi_notify(acpi_handle device, u32 value, void *data)
 {
 	struct cros_ec_device *ec_dev = data;
@@ -324,6 +342,8 @@ static void cros_ec_lpc_acpi_notify(acpi_handle device, u32 value, void *data)
 	if (value == ACPI_NOTIFY_CROS_EC_PANIC) {
 		dev_emerg(ec_dev->dev, "CrOS EC Panic Reported. Shutdown is imminent!");
 		blocking_notifier_call_chain(&ec_dev->panic_notifier, 0, ec_dev);
+		cros_ec_lpc_panic_uevent(ec_dev);
+
 		/* Begin orderly shutdown. Force shutdown after 1 second. */
 		hw_protection_shutdown("CrOS EC Panic", 1000);
 		/* Do not query for other events after a panic is reported */
-- 
2.39.2