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hidpp: extract hidpp20_crc_ccitt into hidpp_generic

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Looks like the hid++ 1.0 devices are also using the same crc computation,
so put it in the generic part.

Signed-off-by: Benjamin Tissoires <benjamin.tissoires@redhat.com>
This commit is contained in:
Benjamin Tissoires
2015-11-25 18:16:36 +01:00
parent df4a12b233
commit 9cc323d80f
3 changed files with 31 additions and 29 deletions
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27
src/hidpp-generic.c
View File

@@ -317,3 +317,30 @@ hidpp_device_set_log_handler(struct hidpp_device *dev,
dev->log_priority = priority;
dev->userdata = userdata;
}
/*
* The following crc computation has been provided by Logitech
*/
#define CRC_CCITT_SEED 0xFFFF
uint16_t
hidpp_crc_ccitt(uint8_t *data, unsigned int length)
{
uint16_t crc, temp, quick;
unsigned int i;
crc = CRC_CCITT_SEED;
for (i = 0; i < length; i++) {
temp = (crc >> 8) ^ (*data++);
crc <<= 8;
quick = temp ^ (temp >> 4);
crc ^= quick;
quick <<= 5;
crc ^= quick;
quick <<= 7;
crc ^= quick;
}
return crc;
}

2
src/hidpp-generic.h
View File

@@ -144,6 +144,8 @@ hidpp_log_buffer(struct hidpp_device *dev,
#define hidpp_log_buf_info(li_, h_, buf_, len_) hidpp_log_buffer(li_, HIDPP_LOG_PRIORITY_INFO, h_, buf_, len_)
#define hidpp_log_buf_error(li_, h_, buf_, len_) hidpp_log_buffer(li_, HIDPP_LOG_PRIORITY_ERROR, h_, buf_, len_)
uint16_t hidpp_crc_ccitt(uint8_t *data, unsigned int length);
static inline uint16_t
hidpp_get_unaligned_be_u16(uint8_t *buf)
{

31
src/hidpp20.c
View File

@@ -920,33 +920,6 @@ int hidpp20_adjustable_dpi_set_sensor_dpi(struct hidpp20_device *device,
#define HIDPP20_PROFILE_SIZE HIDPP20_PAGE_SIZE
#define HIDPP20_BUTTON_HID 0x80
/*
* The following crc computation has been provided by Logitech
*/
#define CRC_CCITT_SEED 0xFFFF
static uint16_t
hidpp20_crc_ccitt(uint8_t *data, unsigned int length)
{
uint16_t crc, temp, quick;
unsigned int i;
crc = CRC_CCITT_SEED;
for (i = 0; i < length; i++) {
temp = (crc >> 8) ^ (*data++);
crc <<= 8;
quick = temp ^ (temp >> 4);
crc ^= quick;
quick <<= 5;
crc ^= quick;
quick <<= 7;
crc ^= quick;
}
return crc;
}
int
hidpp20_onboard_profiles_read_memory(struct hidpp20_device *device,
uint8_t read_rom,
@@ -1097,7 +1070,7 @@ hidpp20_onboard_profiles_write_page(struct hidpp20_device *device,
{
uint16_t crc;
crc = hidpp20_crc_ccitt(data, HIDPP20_PAGE_SIZE - 2);
crc = hidpp_crc_ccitt(data, HIDPP20_PAGE_SIZE - 2);
hidpp_set_unaligned_be_u16(&data[HIDPP20_PROFILE_SIZE - 2], crc);
return hidpp20_onboard_profiles_write_data(device, page, 0x00, data, HIDPP20_PAGE_SIZE);
@@ -1228,7 +1201,7 @@ hidpp20_onboard_profiles_find_and_read_profile(struct hidpp20_device *device,
return rc;
}
crc = hidpp20_crc_ccitt(data, HIDPP20_PROFILE_SIZE - 2);
crc = hidpp_crc_ccitt(data, HIDPP20_PROFILE_SIZE - 2);
read_crc = hidpp_get_unaligned_be_u16(&data[HIDPP20_PROFILE_SIZE - 2]);
if (crc == read_crc)