[PATCH 3/3] platform/chrome: wilco_ec: Add Boot on AC support

[Nick Crews <ncrews@chromium.org>]

Boot on AC is a policy which makes the device boot from S5 when AC
power is connected. This is useful for users who want to run their
device headless or with a dock.

Signed-off-by: Nick Crews <ncrews@chromium.org>
---
 drivers/platform/chrome/wilco_ec/sysfs.c | 52 ++++++++++++++++++++++++
 1 file changed, 52 insertions(+)

diff --git a/drivers/platform/chrome/wilco_ec/sysfs.c b/drivers/platform/chrome/wilco_ec/sysfs.c
index ec5211257a58..52cbdb1f30b6 100644
--- a/drivers/platform/chrome/wilco_ec/sysfs.c
+++ b/drivers/platform/chrome/wilco_ec/sysfs.c
@@ -5,6 +5,10 @@
  * Sysfs properties used to modify EC-controlled features on Wilco devices.
  * The entries will appear under /sys/bus/platform/devices/GOOG000C:00/
  *
+ * Boot on AC is a policy which makes the device boot from S5 when AC
+ * power is connected. This is useful for users who want to run their
+ * device headless or with a dock.
+ *
  * USB PowerShare is a policy which affects charging via the special
  * USB PowerShare port (marked with a small lightning bolt or battery icon)
  * when in low power states:
@@ -18,6 +22,18 @@
 #include <linux/platform_data/wilco-ec.h>
 #include <linux/sysfs.h>
 
+#define CMD_KB_CMOS			0x7C
+#define SUB_CMD_KB_CMOS_AUTO_ON		0x03
+
+struct boot_on_ac_request {
+	u8 cmd;			/* Always CMD_KB_CMOS */
+	u8 reserved1;
+	u8 sub_cmd;		/* Always SUB_CMD_KB_CMOS_AUTO_ON */
+	u8 reserved3to5[3];
+	u8 val;			/* Either 0 or 1*/
+	u8 reserved7;
+} __packed;
+
 #define CMD_USB_POWER_SHARE 0x39
 
 enum usb_power_share_op {
@@ -38,6 +54,41 @@ struct usb_power_share_response {
 	u8 val;		/* When getting, set by EC to either 0 or 1 */
 } __packed;
 
+static ssize_t boot_on_ac_store(struct device *dev,
+				struct device_attribute *attr,
+				const char *buf, size_t count)
+{
+	struct wilco_ec_device *ec = dev_get_drvdata(dev);
+	struct boot_on_ac_request rq;
+	struct wilco_ec_message msg;
+	int ret;
+	u8 val;
+
+	ret = kstrtou8(buf, 10, &val);
+	if (ret < 0)
+		return ret;
+
+	if (val != 0 && val != 1)
+		return -EINVAL;
+
+	memset(&rq, 0, sizeof(rq));
+	rq.cmd = CMD_KB_CMOS;
+	rq.sub_cmd = SUB_CMD_KB_CMOS_AUTO_ON;
+	rq.val = val;
+
+	memset(&msg, 0, sizeof(msg));
+	msg.type = WILCO_EC_MSG_LEGACY;
+	msg.request_data = &rq;
+	msg.request_size = sizeof(rq);
+	ret = wilco_ec_mailbox(ec, &msg);
+	if (ret < 0)
+		return ret;
+
+	return count;
+}
+
+static DEVICE_ATTR_WO(boot_on_ac);
+
 static int send_usb_power_share(struct wilco_ec_device *ec,
 				struct usb_power_share_request *rq,
 				struct usb_power_share_response *rs)
@@ -110,6 +161,7 @@ static ssize_t usb_power_share_store(struct device *dev,
 static DEVICE_ATTR_RW(usb_power_share);
 
 static struct attribute *wilco_dev_attrs[] = {
+	&dev_attr_boot_on_ac.attr,
 	&dev_attr_usb_power_share.attr,
 	NULL,
 };
-- 
2.20.1