platform/x86: ideapad-laptop: Add fn-lock setting

Some of latest Lenovo ideapad laptops do not have UEFI/BIOS setting for
switching fn-lock mode. This commit adds related acpi calls to ideapad
platform driver. However setting is available via sysfs.
Signed-off-by: Oleg Keri <ezhi99@gmail.com>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>

Documentation/ABI/testing/sysfs-platform-ideapad-laptop

@@ -25,3 +25,16 @@ Description:
 		Control touchpad mode.
 			* 1 -> Switched On
 			* 0 -> Switched Off
+
+What:		/sys/bus/pci/devices/<bdf>/<device>/VPC2004:00/fn_lock
+Date:		May 2018
+KernelVersion:	4.18
+Contact:	"Oleg Keri <ezhi99@gmail.com>"
+Description:
+		Control fn-lock mode.
+			* 1 -> Switched On
+			* 0 -> Switched Off
+
+		For example:
+		# echo "0" >	\
+		/sys/bus/pci/devices/0000:00:1f.0/PNP0C09:00/VPC2004:00/fn_lock

drivers/platform/x86/ideapad-laptop.c

@@ -43,6 +43,7 @@
 #define IDEAPAD_RFKILL_DEV_NUM	(3)
 
 #define BM_CONSERVATION_BIT (5)
+#define HA_FNLOCK_BIT       (10)
 
 #define CFG_BT_BIT	(16)
 #define CFG_3G_BIT	(17)
@@ -59,6 +60,8 @@ static const char *const ideapad_wmi_fnesc_events[] = {
 enum {
 	BMCMD_CONSERVATION_ON = 3,
 	BMCMD_CONSERVATION_OFF = 5,
+	HACMD_FNLOCK_ON = 0xe,
+	HACMD_FNLOCK_OFF = 0xf,
 };
 
 enum {
@@ -139,11 +142,11 @@ static int method_gbmd(acpi_handle handle, unsigned long *ret)
 	return result;
 }
 
-static int method_sbmc(acpi_handle handle, int cmd)
+static int method_int1(acpi_handle handle, char *method, int cmd)
 {
 	acpi_status status;
 
-	status = acpi_execute_simple_method(handle, "SBMC", cmd);
+	status = acpi_execute_simple_method(handle, method, cmd);
 	return ACPI_FAILURE(status) ? -1 : 0;
 }
 
@@ -487,7 +490,7 @@ static ssize_t conservation_mode_store(struct device *dev,
 	if (ret)
 		return ret;
 
-	ret = method_sbmc(priv->adev->handle, state ?
+	ret = method_int1(priv->adev->handle, "SBMC", state ?
 					      BMCMD_CONSERVATION_ON :
 					      BMCMD_CONSERVATION_OFF);
 	if (ret < 0)
@@ -497,11 +500,51 @@ static ssize_t conservation_mode_store(struct device *dev,
 
 static DEVICE_ATTR_RW(conservation_mode);
 
+static ssize_t fn_lock_show(struct device *dev,
+			    struct device_attribute *attr,
+			    char *buf)
+{
+	struct ideapad_private *priv = dev_get_drvdata(dev);
+	unsigned long result;
+	int hals;
+	int fail = read_method_int(priv->adev->handle, "HALS", &hals);
+
+	if (fail)
+		return sprintf(buf, "-1\n");
+
+	result = hals;
+	return sprintf(buf, "%u\n", test_bit(HA_FNLOCK_BIT, &result));
+}
+
+static ssize_t fn_lock_store(struct device *dev,
+			     struct device_attribute *attr,
+			     const char *buf, size_t count)
+{
+	struct ideapad_private *priv = dev_get_drvdata(dev);
+	bool state;
+	int ret;
+
+	ret = kstrtobool(buf, &state);
+	if (ret)
+		return ret;
+
+	ret = method_int1(priv->adev->handle, "SALS", state ?
+			  HACMD_FNLOCK_ON :
+			  HACMD_FNLOCK_OFF);
+	if (ret < 0)
+		return -EIO;
+	return count;
+}
+
+static DEVICE_ATTR_RW(fn_lock);
+
+
 static struct attribute *ideapad_attributes[] = {
 	&dev_attr_camera_power.attr,
 	&dev_attr_fan_mode.attr,
 	&dev_attr_touchpad.attr,
 	&dev_attr_conservation_mode.attr,
+	&dev_attr_fn_lock.attr,
 	NULL
 };
 
@@ -522,6 +565,9 @@ static umode_t ideapad_is_visible(struct kobject *kobj,
 	} else if (attr == &dev_attr_conservation_mode.attr) {
 		supported = acpi_has_method(priv->adev->handle, "GBMD") &&
 			    acpi_has_method(priv->adev->handle, "SBMC");
+	} else if (attr == &dev_attr_fn_lock.attr) {
+		supported = acpi_has_method(priv->adev->handle, "HALS") &&
+			acpi_has_method(priv->adev->handle, "SALS");
 	} else
 		supported = true;