diff options
Diffstat (limited to 'drivers/hid')
| -rw-r--r-- | drivers/hid/wacom.h | 15 | ||||
| -rw-r--r-- | drivers/hid/wacom_wac.c | 10 |
2 files changed, 21 insertions, 4 deletions
diff --git a/drivers/hid/wacom.h b/drivers/hid/wacom.h index 4a7f8d363220..203d27d198b8 100644 --- a/drivers/hid/wacom.h +++ b/drivers/hid/wacom.h @@ -202,6 +202,21 @@ static inline void wacom_schedule_work(struct wacom_wac *wacom_wac, } } +/* + * Convert a signed 32-bit integer to an unsigned n-bit integer. Undoes + * the normally-helpful work of 'hid_snto32' for fields that use signed + * ranges for questionable reasons. + */ +static inline __u32 wacom_s32tou(s32 value, __u8 n) +{ + switch (n) { + case 8: return ((__u8)value); + case 16: return ((__u16)value); + case 32: return ((__u32)value); + } + return value & (1 << (n - 1)) ? value & (~(~0U << n)) : value; +} + extern const struct hid_device_id wacom_ids[]; void wacom_wac_irq(struct wacom_wac *wacom_wac, size_t len); diff --git a/drivers/hid/wacom_wac.c b/drivers/hid/wacom_wac.c index 2b0a5b8ca6e6..ccb74529bc78 100644 --- a/drivers/hid/wacom_wac.c +++ b/drivers/hid/wacom_wac.c @@ -2303,7 +2303,7 @@ static void wacom_wac_pen_event(struct hid_device *hdev, struct hid_field *field case HID_DG_TOOLSERIALNUMBER: if (value) { wacom_wac->serial[0] = (wacom_wac->serial[0] & ~0xFFFFFFFFULL); - wacom_wac->serial[0] |= (__u32)value; + wacom_wac->serial[0] |= wacom_s32tou(value, field->report_size); } return; case HID_DG_TWIST: @@ -2319,15 +2319,17 @@ static void wacom_wac_pen_event(struct hid_device *hdev, struct hid_field *field return; case WACOM_HID_WD_SERIALHI: if (value) { + __u32 raw_value = wacom_s32tou(value, field->report_size); + wacom_wac->serial[0] = (wacom_wac->serial[0] & 0xFFFFFFFF); - wacom_wac->serial[0] |= ((__u64)value) << 32; + wacom_wac->serial[0] |= ((__u64)raw_value) << 32; /* * Non-USI EMR devices may contain additional tool type * information here. See WACOM_HID_WD_TOOLTYPE case for * more details. */ if (value >> 20 == 1) { - wacom_wac->id[0] |= value & 0xFFFFF; + wacom_wac->id[0] |= raw_value & 0xFFFFF; } } return; @@ -2339,7 +2341,7 @@ static void wacom_wac_pen_event(struct hid_device *hdev, struct hid_field *field * bitwise OR so the complete value can be built * up over time :( */ - wacom_wac->id[0] |= value; + wacom_wac->id[0] |= wacom_s32tou(value, field->report_size); return; case WACOM_HID_WD_OFFSETLEFT: if (features->offset_left && value != features->offset_left) |