[PATCH] input: cros_ec_keyb: Add an EC event for sysrq

From: Rajat Jain
Date: Thu Mar 30 2017 - 18:18:32 EST


Some form factors (detachables / tablets) may not have a keyboard and
thus user may have to resort to using a defined EC UI to send sysrq(s)
to the kernel in order to collect crash info etc. This UI typically
is in the form of user pressing volume / power buttons in some specific
sequence and for some specific time. Add a new EC event that allows EC
to communicate the sysrq to the AP.

(We're skipping event number 5 because it has been reserved for
something else)

Signed-off-by: Rajat Jain <rajatja@xxxxxxxxxx>
---
drivers/input/keyboard/cros_ec_keyb.c | 7 +++++++
include/linux/mfd/cros_ec_commands.h | 4 ++++
2 files changed, 11 insertions(+)

diff --git a/drivers/input/keyboard/cros_ec_keyb.c b/drivers/input/keyboard/cros_ec_keyb.c
index 6a250d65f8fe..00a3a830cd3a 100644
--- a/drivers/input/keyboard/cros_ec_keyb.c
+++ b/drivers/input/keyboard/cros_ec_keyb.c
@@ -30,6 +30,7 @@
#include <linux/notifier.h>
#include <linux/platform_device.h>
#include <linux/slab.h>
+#include <linux/sysrq.h>
#include <linux/input/matrix_keypad.h>
#include <linux/mfd/cros_ec.h>
#include <linux/mfd/cros_ec_commands.h>
@@ -260,6 +261,12 @@ static int cros_ec_keyb_work(struct notifier_block *nb,
ckdev->ec->event_size);
break;

+ case EC_MKBP_EVENT_SYSRQ:
+ val = get_unaligned_le32(&ckdev->ec->event_data.data.sysrq);
+ dev_dbg(ckdev->dev, "sysrq code from EC : %#x\n", val);
+ handle_sysrq(val);
+ break;
+
case EC_MKBP_EVENT_BUTTON:
case EC_MKBP_EVENT_SWITCH:
/*
diff --git a/include/linux/mfd/cros_ec_commands.h b/include/linux/mfd/cros_ec_commands.h
index f1ef6388c233..c93e7e0300ef 100644
--- a/include/linux/mfd/cros_ec_commands.h
+++ b/include/linux/mfd/cros_ec_commands.h
@@ -2041,6 +2041,9 @@ enum ec_mkbp_event {
/* The state of the switches have changed. */
EC_MKBP_EVENT_SWITCH = 4,

+ /* EC sent a sysrq command */
+ EC_MKBP_EVENT_SYSRQ = 6,
+
/* Number of MKBP events */
EC_MKBP_EVENT_COUNT,
};
@@ -2053,6 +2056,7 @@ union ec_response_get_next_data {

uint32_t buttons;
uint32_t switches;
+ uint32_t sysrq;
} __packed;

struct ec_response_get_next_event {
--
2.12.2.564.g063fe858b8-goog