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-rw-r--r--drivers/hid/wacom.h15
1 files changed, 15 insertions, 0 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);