diff options
| author | Benjamin Tissoires <benjamin.tissoires@gmail.com> | 2012-11-14 16:59:15 +0100 |
|---|---|---|
| committer | Jiri Kosina <jkosina@suse.cz> | 2012-11-15 10:07:55 +0100 |
| commit | 774638386826621c984ab6994439f474709cac5e (patch) | |
| tree | 897fb8a15947768f7dc9521027c7c20fe830c1bf /drivers/hid/hid-input.c | |
| parent | ccdd699411b77c463022ebac311eb4a06ca56db4 (diff) | |
| download | lwn-774638386826621c984ab6994439f474709cac5e.tar.gz lwn-774638386826621c984ab6994439f474709cac5e.zip | |
HID: fix unit exponent parsing
HID spec details special values for the HID field unit exponent.
Basically, the range [0x8..0xf] correspond to [-8..-1], so this is
a standard two's complement on a half-byte.
Signed-off-by: Benjamin Tissoires <benjamin.tissoires@gmail.com>
Acked-by: Jiri Kosina <jkosina@suse.cz>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
Diffstat (limited to 'drivers/hid/hid-input.c')
| -rw-r--r-- | drivers/hid/hid-input.c | 13 |
1 files changed, 9 insertions, 4 deletions
diff --git a/drivers/hid/hid-input.c b/drivers/hid/hid-input.c index 1b0adc3f7803..007a9433bfa7 100644 --- a/drivers/hid/hid-input.c +++ b/drivers/hid/hid-input.c @@ -192,7 +192,6 @@ static int hidinput_setkeycode(struct input_dev *dev, return -EINVAL; } - /** * hidinput_calc_abs_res - calculate an absolute axis resolution * @field: the HID report field to calculate resolution for @@ -235,17 +234,23 @@ __s32 hidinput_calc_abs_res(const struct hid_field *field, __u16 code) case ABS_MT_TOOL_Y: case ABS_MT_TOUCH_MAJOR: case ABS_MT_TOUCH_MINOR: - if (field->unit == 0x11) { /* If centimeters */ + if (field->unit & 0xffffff00) /* Not a length */ + return 0; + unit_exponent += hid_snto32(field->unit >> 4, 4) - 1; + switch (field->unit & 0xf) { + case 0x1: /* If centimeters */ /* Convert to millimeters */ unit_exponent += 1; - } else if (field->unit == 0x13) { /* If inches */ + break; + case 0x3: /* If inches */ /* Convert to millimeters */ prev = physical_extents; physical_extents *= 254; if (physical_extents < prev) return 0; unit_exponent -= 1; - } else { + break; + default: return 0; } break; |