platform/chrome: cros_ec: Report EC panic as uevent

Create a uevent when an EC panic is detected. This will allow udev rules
to trigger when a panic occurs. For example, a udev rule could be added to
capture an EC coredump. This approach avoids the need to stuff all the
processing into the driver.

Signed-off-by: Rob Barnes <robbarnes@google.com>
Reviewed-by: Prashant Malani <pmalani@chromium.org>
Signed-off-by: Tzung-Bi Shih <tzungbi@kernel.org>
Link: https://lore.kernel.org/r/20230509232624.3120347-1-robbarnes@google.com

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>
@@ -315,6 +316,7 @@ static int cros_ec_lpc_readmem(struct cros_ec_device *ec, unsigned int offset,
 
 static void cros_ec_lpc_acpi_notify(acpi_handle device, u32 value, void *data)
 {
+	static const char *env[] = { "ERROR=PANIC", NULL };
 	struct cros_ec_device *ec_dev = data;
 	bool ec_has_more_events;
 	int ret;
@@ -324,6 +326,7 @@ 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);
+		kobject_uevent_env(&ec_dev->dev->kobj, KOBJ_CHANGE, (char **)env);
 		/* 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 */