Support getting signed and unsigned HID data.

Submitted by:	Alex Deiter
Reviewed by:	Hans Petter Selaksy
This commit is contained in:
thompsa 2010-05-12 22:50:23 +00:00
parent f006c8aa86
commit f7f314b3e7
3 changed files with 33 additions and 11 deletions

View File

@ -63,13 +63,17 @@ hid_get_data(const void *p, const hid_item_t *h)
data = 0;
for (i = 0; i <= end; i++)
data |= buf[offs + i] << (i*8);
/* Correctly shift down data */
data >>= hpos % 8;
data &= (1 << hsize) - 1;
if (h->logical_minimum < 0) {
/* Need to sign extend */
hsize = sizeof data * 8 - hsize;
data = (data << hsize) >> hsize;
}
hsize = 32 - hsize;
/* Mask and sign extend in one */
if ((h->logical_minimum < 0) || (h->logical_maximum < 0))
data = (int32_t)((int32_t)data << hsize) >> hsize;
else
data = (uint32_t)((uint32_t)data << hsize) >> hsize;
return (data);
}

View File

@ -646,8 +646,9 @@ hid_locate(const void *desc, usb_size_t size, uint32_t u, enum hid_kind k,
/*------------------------------------------------------------------------*
* hid_get_data
*------------------------------------------------------------------------*/
uint32_t
hid_get_data(const uint8_t *buf, usb_size_t len, struct hid_location *loc)
static uint32_t
hid_get_data_sub(const uint8_t *buf, usb_size_t len, struct hid_location *loc,
int is_signed)
{
uint32_t hpos = loc->pos;
uint32_t hsize = loc->size;
@ -676,16 +677,31 @@ hid_get_data(const uint8_t *buf, usb_size_t len, struct hid_location *loc)
/* Correctly shift down data */
data = (data >> (hpos % 8));
n = 32 - hsize;
/* Mask and sign extend in one */
n = 32 - hsize;
data = ((int32_t)data << n) >> n;
if (is_signed != 0)
data = (int32_t)((int32_t)data << n) >> n;
else
data = (uint32_t)((uint32_t)data << n) >> n;
DPRINTFN(11, "hid_get_data: loc %d/%d = %lu\n",
loc->pos, loc->size, (long)data);
return (data);
}
int32_t
hid_get_data(const uint8_t *buf, usb_size_t len, struct hid_location *loc)
{
return (hid_get_data_sub(buf, len, loc, 1));
}
uint32_t
hid_get_data_unsigned(const uint8_t *buf, usb_size_t len, struct hid_location *loc)
{
return (hid_get_data_sub(buf, len, loc, 0));
}
/*------------------------------------------------------------------------*
* hid_is_collection
*------------------------------------------------------------------------*/

View File

@ -229,7 +229,9 @@ int hid_report_size(const void *buf, usb_size_t len, enum hid_kind k,
int hid_locate(const void *desc, usb_size_t size, uint32_t usage,
enum hid_kind kind, uint8_t index, struct hid_location *loc,
uint32_t *flags, uint8_t *id);
uint32_t hid_get_data(const uint8_t *buf, usb_size_t len,
int32_t hid_get_data(const uint8_t *buf, usb_size_t len,
struct hid_location *loc);
uint32_t hid_get_data_unsigned(const uint8_t *buf, usb_size_t len,
struct hid_location *loc);
int hid_is_collection(const void *desc, usb_size_t size, uint32_t usage);
struct usb_hid_descriptor *hid_get_descriptor_from_usb(