[PATCH] input: (gtco) use sign_extend32() for sign extension

From: Martin Kepplinger
Date: Fri Jan 23 2015 - 07:30:07 EST


Signed-off-by: Martin Kepplinger <martink@xxxxxxxxx>
---
Despite it's name, sign_extend32() is safe to use for 8 and 16 bit types too.


drivers/input/tablet/gtco.c | 11 +++--------
1 file changed, 3 insertions(+), 8 deletions(-)

diff --git a/drivers/input/tablet/gtco.c b/drivers/input/tablet/gtco.c
index 8580456..272a838 100644
--- a/drivers/input/tablet/gtco.c
+++ b/drivers/input/tablet/gtco.c
@@ -59,7 +59,7 @@ Scott Hill shill@xxxxxxxxxxxxxxx
#include <asm/uaccess.h>
#include <asm/unaligned.h>
#include <asm/byteorder.h>
-
+#include <linux/bitops.h>

#include <linux/usb/input.h>

@@ -666,13 +666,8 @@ static void gtco_urb_callback(struct urb *urbinfo)
case 4:
/* Tilt */

- /* Sign extend these 7 bit numbers. */
- if (device->buffer[6] & 0x40)
- device->buffer[6] |= 0x80;
-
- if (device->buffer[7] & 0x40)
- device->buffer[7] |= 0x80;
-
+ device->buffer[6] = sign_extend32(device->buffer[6], 6);
+ device->buffer[7] = sign_extend32(device->buffer[7], 6);

valsigned = (device->buffer[6]);
input_report_abs(inputdev, ABS_TILT_X, (s32)valsigned);
--
2.1.4

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