ideapad: add Lenovo IdeaPad Z570 support (part 3)

The patch adds support for Lenovo IdeaPad Z570 laptop. It makes all special
keys working, adds possibility to control fan like Windows does, controls
Touchpad Disabled LED, toggles touchpad state via keyboard controller and
corrects touchpad behavior on resume from suspend. It is new, modified
version of patch. Now it does not depend on psmouse and does not need patching
of input subsystem.

Signed-off-by: Maxim Mikityanskiy <[e-mail]>

This is the part 3 for fan control

Signed-off-by: Ike Panhc <[e-mail]>
Signed-off-by: Matthew Garrett <[e-mail]>

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

···
 Description:
 		Control the power of camera module. 1 means on, 0 means off.
 
+What:		/sys/devices/platform/ideapad/fan_mode
+Date:		June 2012
+KernelVersion:	3.6
+Contact:	"Maxim Mikityanskiy <[e-mail]>"
+Description:
+		Change fan mode
+		There are four available modes:
+			* 0 -> Super Silent Mode
+			* 1 -> Standard Mode
+			* 2 -> Dust Cleaning
+			* 4 -> Efficient Thermal Dissipation Mode
 

drivers/platform/x86/ideapad-laptop.c

···
 	VPCCMD_R_3G,
 	VPCCMD_W_3G,
 	VPCCMD_R_ODD, /* 0x21 */
-	VPCCMD_R_RF = 0x23,
+	VPCCMD_W_FAN,
+	VPCCMD_R_RF,
 	VPCCMD_W_RF,
+	VPCCMD_R_FAN = 0x2B,
 	VPCCMD_R_SPECIAL_BUTTONS = 0x31,
 	VPCCMD_W_BL_POWER = 0x33,
 };
···
 		return -EINVAL;
 	ret = write_ec_cmd(ideapad_handle, VPCCMD_W_CAMERA, state);
 	if (ret < 0)
-		return ret;
+		return -EIO;
 	return count;
 }
 
 static DEVICE_ATTR(camera_power, 0644, show_ideapad_cam, store_ideapad_cam);
 
+static ssize_t show_ideapad_fan(struct device *dev,
+				struct device_attribute *attr,
+				char *buf)
+{
+	unsigned long result;
+
+	if (read_ec_data(ideapad_handle, VPCCMD_R_FAN, &result))
+		return sprintf(buf, "-1\n");
+	return sprintf(buf, "%lu\n", result);
+}
+
+static ssize_t store_ideapad_fan(struct device *dev,
+				 struct device_attribute *attr,
+				 const char *buf, size_t count)
+{
+	int ret, state;
+
+	if (!count)
+		return 0;
+	if (sscanf(buf, "%i", &state) != 1)
+		return -EINVAL;
+	if (state < 0 || state > 4 || state == 3)
+		return -EINVAL;
+	ret = write_ec_cmd(ideapad_handle, VPCCMD_W_FAN, state);
+	if (ret < 0)
+		return -EIO;
+	return count;
+}
+
+static DEVICE_ATTR(fan_mode, 0644, show_ideapad_fan, store_ideapad_fan);
+
 static struct attribute *ideapad_attributes[] = {
 	&dev_attr_camera_power.attr,
+	&dev_attr_fan_mode.attr,
 	NULL
 };
 
···
 
 	if (attr == &dev_attr_camera_power.attr)
 		supported = test_bit(CFG_CAMERA_BIT, &(priv->cfg));
-	else
+	else if (attr == &dev_attr_fan_mode.attr) {
+		unsigned long value;
+		supported = !read_ec_data(ideapad_handle, VPCCMD_R_FAN, &value);
+	} else
 		supported = true;
 
 	return supported ? attr->mode : 0;