HID: export hidinput_calc_abs_res

Exporting the function allows us to calculate the resolution in third
party drivers like hid-multitouch.
This patch also complete the function with additional valid axes.

Signed-off-by: Benjamin Tissoires <benjamin.tissoires@gmail.com>
Acked-by: Jiri Kosina <jkosina@suse.cz>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>

2 files changed, 9 insertions, 1 deletions

diff --git a/drivers/hid/hid-input.c b/drivers/hid/hid-input.c
index d917c0d53685..d1ec571bdb3b 100644
--- a/drivers/hid/hid-input.c
+++ b/drivers/hid/hid-input.c
@@ -208,7 +208,7 @@ static int hidinput_setkeycode(struct input_dev *dev,
  * Only exponent 1 length units are processed. Centimeters and inches are
  * converted to millimeters. Degrees are converted to radians.
  */
-static __s32 hidinput_calc_abs_res(const struct hid_field *field, __u16 code)
+__s32 hidinput_calc_abs_res(const struct hid_field *field, __u16 code)
 {
         __s32 unit_exponent = field->unit_exponent;
         __s32 logical_extents = field->logical_maximum -
@@ -229,6 +229,12 @@ static __s32 hidinput_calc_abs_res(const struct hid_field *field, __u16 code)
         case ABS_X:
         case ABS_Y:
         case ABS_Z:
+        case ABS_MT_POSITION_X:
+        case ABS_MT_POSITION_Y:
+        case ABS_MT_TOOL_X:
+        case ABS_MT_TOOL_Y:
+        case ABS_MT_TOUCH_MAJOR:
+        case ABS_MT_TOUCH_MINOR:
                 if (field->unit == 0x11) {              /* If centimeters */
                         /* Convert to millimeters */
                         unit_exponent += 1;
@@ -283,6 +289,7 @@ static __s32 hidinput_calc_abs_res(const struct hid_field *field, __u16 code)
         /* Calculate resolution */
         return logical_extents / physical_extents;
 }
+EXPORT_SYMBOL_GPL(hidinput_calc_abs_res);
 
 #ifdef CONFIG_HID_BATTERY_STRENGTH
 static enum power_supply_property hidinput_battery_props[] = {
diff --git a/drivers/hid/hid-multitouch.c b/drivers/hid/hid-multitouch.c
index 7867d69f0efe..3687f797b731 100644
--- a/drivers/hid/hid-multitouch.c
+++ b/drivers/hid/hid-multitouch.c
@@ -297,6 +297,7 @@ static void set_abs(struct input_dev *input, unsigned int code,
         int fmax = field->logical_maximum;
         int fuzz = snratio ? (fmax - fmin) / snratio : 0;
         input_set_abs_params(input, code, fmin, fmax, fuzz, 0);
+        input_abs_set_res(input, code, hidinput_calc_abs_res(field, code));
 }
 
 static void mt_store_field(struct hid_usage *usage, struct mt_device *td,