/**
* \brief Sets a Register of the TDC-GP22.
* \param[in] reg is the readable register of the GP22.
* \param[out] value is a pointer to the storage of the register value.
* \param[in] len indicates how many bytes have to read.
* \return FALSE if the SPI transmission get a time out.
*/
uint8_t bsp_GP22RegRead(uint8_t reg, uint32_t *value, uint8_t len) {
uint8_t success;
uint8_t tx_bytes[5];
uint8_t rx_bytes[5];
assert(GP22_IS_RD(reg));
assert(len==2 || len==4);
/* First send a read command */
tx_bytes[0] = reg;
success = bsp_SPITransmitBlocked(BSP_SPI_CS_GP22, tx_bytes, len+1, rx_bytes);
/* Transform received bytes to a 32 bit integer */
if (success) {
if (len == 2) {
*value = bytes2short(&(rx_bytes[1]));
}
else if (len == 4) {
*value = bytes2long(&(rx_bytes[1]));
}
else {
success = 0;
}
}
return success;
}
/* Reads a long from the file */
static uint32_t read_long(struct tiff_file_desc *tfd, bool *error)
{
uint32_t value = -1;
if (tfd != NULL && tfd->file != NULL && !*error) {
uint8_t buf[4];
size_t ret;
ret = fread(buf, 1, sizeof(buf), tfd->file);
if (ret != sizeof(buf))
*error = true;
else
value = bytes2long(buf, tfd->is_le);
}
else
*error = true;
return value;
}
/* Reads an IFD entry and updates the right tiff fields */
static void read_ifd_entry(struct tiff_file_desc *tfd, bool *error)
{
if (error == NULL || *error)
return;
uint16_t tag;
uint16_t type;
uint32_t count;
uint32_t offset;
uint32_t value;
uint32_t next_value = 0;
uint32_t cur_pos;
uint8_t buf[4];
size_t ret;
/* Identification tag */
tag = read_short(tfd, error);
/* Type */
type = read_short(tfd, error);
/* Number of values */
count = read_long(tfd, error);
/* Value */
ret = fread(buf, 1, sizeof(buf), tfd->file);
if (ret != sizeof(buf))
*error = true;
offset = bytes2long(buf, tfd->is_le);
switch (type) {
case BYTE:
value = buf[0];
break;
case SHORT:
value = bytes2short(buf, tfd->is_le);
uint8_t *next_buf = &buf[2];
next_value = bytes2short(next_buf, tfd->is_le);
break;
case LONG:
value = offset;
break;
/* Unused values */
case ASCII:
case RATIONAL:
default:
value = 0;
}
switch(tag) {
/* ImageWidth */
case 0x0100:
tfd->width = value;
break;
/* ImageLength */
case 0x0101:
tfd->height = value;
break;
/* BitsPerSample */
case 0x0102:
if (count <= 2)
tfd->bits_per_sample = value;
else {
cur_pos = ftell(tfd->file);
fseek(tfd->file, offset, SEEK_SET);
tfd->bits_per_sample = read_short(tfd, error);
fseek(tfd->file, cur_pos, SEEK_SET);
}
break;
/* Compression */
case 0x0103:
tfd->compression = value;
break;
/* PhotometricInterpretation */
case 0x0106:
tfd->photometric_interpretation = value;
break;
/* StripOffsets */
case 0x0111:
tfd->nb_strips = count;
tfd->strip_offsets = calloc(count, sizeof(uint32_t));
if (tfd->strip_offsets == NULL) {
*error = true;
return;
}
if ((count > 1 && type == LONG) || (count > 2 && type == SHORT)) {
cur_pos = ftell(tfd->file);
fseek(tfd->file, offset, SEEK_SET);
for (uint32_t i = 0; i < count; ++i)
tfd->strip_offsets[i] = read_long(tfd, error);
fseek(tfd->file, cur_pos, SEEK_SET);
} else if (type == SHORT && count == 2) {
tfd->strip_offsets[0] = value;
tfd->strip_offsets[1] = next_value;
} else
tfd->strip_offsets[0] = value;
break;
/* SamplesPerPixel */
case 0x0115:
tfd->samples_per_pixels = value;
break;
/* RowsPerStrip */
case 0x0116:
/*
* Big values mean infinity,
* in which case there are no strips
*/
if (value > 0xFFFFFF)
value = 0;
tfd->rows_per_strip = value;
break;
/* StripByteCounts */
case 0x0117:
tfd->strip_bytes_count = count;
tfd->strip_bytes = calloc(count, sizeof(uint32_t));
if (tfd->strip_bytes == NULL) {
*error = true;
return;
}
if ((count > 1 && type == LONG) || (count > 2 && type == SHORT)) {
cur_pos = ftell(tfd->file);
fseek(tfd->file, offset, SEEK_SET);
for (uint32_t i = 0; i < count; ++i)
tfd->strip_bytes[i] = read_long(tfd, error);
fseek(tfd->file, cur_pos, SEEK_SET);
} else if (type == SHORT && count == 2) {
tfd->strip_bytes[0] = value;
tfd->strip_bytes[1] = next_value;
}
else
tfd->strip_bytes[0] = value;
}
}
