static int ad7298_ring_preenable(struct iio_dev *indio_dev)
{
struct ad7298_state *st = iio_priv(indio_dev);
struct iio_buffer *ring = indio_dev->buffer;
size_t d_size;
int i, m;
unsigned short command;
int scan_count = bitmap_weight(indio_dev->active_scan_mask,
indio_dev->masklength);
d_size = scan_count * (AD7298_STORAGE_BITS / 8);
if (ring->scan_timestamp) {
d_size += sizeof(s64);
if (d_size % sizeof(s64))
d_size += sizeof(s64) - (d_size % sizeof(s64));
}
if (ring->access->set_bytes_per_datum)
ring->access->set_bytes_per_datum(ring, d_size);
st->d_size = d_size;
command = AD7298_WRITE | st->ext_ref;
for (i = 0, m = AD7298_CH(0); i < AD7298_MAX_CHAN; i++, m >>= 1)
if (test_bit(i, indio_dev->active_scan_mask))
command |= m;
st->tx_buf[0] = cpu_to_be16(command);
/* */
st->ring_xfer[0].tx_buf = &st->tx_buf[0];
st->ring_xfer[0].len = 2;
st->ring_xfer[0].cs_change = 1;
st->ring_xfer[1].tx_buf = &st->tx_buf[1];
st->ring_xfer[1].len = 2;
st->ring_xfer[1].cs_change = 1;
spi_message_init(&st->ring_msg);
spi_message_add_tail(&st->ring_xfer[0], &st->ring_msg);
spi_message_add_tail(&st->ring_xfer[1], &st->ring_msg);
for (i = 0; i < scan_count; i++) {
st->ring_xfer[i + 2].rx_buf = &st->rx_buf[i];
st->ring_xfer[i + 2].len = 2;
st->ring_xfer[i + 2].cs_change = 1;
spi_message_add_tail(&st->ring_xfer[i + 2], &st->ring_msg);
}
/* */
st->ring_xfer[i + 1].cs_change = 0;
return 0;
}
/**
* ad7298_ring_preenable() setup the parameters of the ring before enabling
*
* The complex nature of the setting of the number of bytes per datum is due
* to this driver currently ensuring that the timestamp is stored at an 8
* byte boundary.
**/
static int ad7298_ring_preenable(struct iio_dev *indio_dev)
{
struct ad7298_state *st = iio_priv(indio_dev);
struct iio_ring_buffer *ring = indio_dev->ring;
size_t d_size;
int i, m;
unsigned short command;
d_size = ring->scan_count * (AD7298_STORAGE_BITS / 8);
if (ring->scan_timestamp) {
d_size += sizeof(s64);
if (d_size % sizeof(s64))
d_size += sizeof(s64) - (d_size % sizeof(s64));
}
if (ring->access->set_bytes_per_datum)
ring->access->set_bytes_per_datum(ring, d_size);
st->d_size = d_size;
command = AD7298_WRITE | st->ext_ref;
for (i = 0, m = AD7298_CH(0); i < AD7298_MAX_CHAN; i++, m >>= 1)
if (ring->scan_mask & (1 << i))
command |= m;
st->tx_buf[0] = cpu_to_be16(command);
/* build spi ring message */
st->ring_xfer[0].tx_buf = &st->tx_buf[0];
st->ring_xfer[0].len = 2;
st->ring_xfer[0].cs_change = 1;
st->ring_xfer[1].tx_buf = &st->tx_buf[1];
st->ring_xfer[1].len = 2;
st->ring_xfer[1].cs_change = 1;
spi_message_init(&st->ring_msg);
spi_message_add_tail(&st->ring_xfer[0], &st->ring_msg);
spi_message_add_tail(&st->ring_xfer[1], &st->ring_msg);
for (i = 0; i < ring->scan_count; i++) {
st->ring_xfer[i + 2].rx_buf = &st->rx_buf[i];
st->ring_xfer[i + 2].len = 2;
st->ring_xfer[i + 2].cs_change = 1;
spi_message_add_tail(&st->ring_xfer[i + 2], &st->ring_msg);
}
/* make sure last transfer cs_change is not set */
st->ring_xfer[i + 1].cs_change = 0;
return 0;
}
/**
* ad7298_update_scan_mode() setup the spi transfer buffer for the new scan mask
**/
static int ad7298_update_scan_mode(struct iio_dev *indio_dev,
const unsigned long *active_scan_mask)
{
struct ad7298_state *st = iio_priv(indio_dev);
int i, m;
unsigned short command;
int scan_count;
/* Now compute overall size */
scan_count = bitmap_weight(active_scan_mask, indio_dev->masklength);
command = AD7298_WRITE | st->ext_ref;
for (i = 0, m = AD7298_CH(0); i < AD7298_MAX_CHAN; i++, m >>= 1)
if (test_bit(i, active_scan_mask))
command |= m;
st->tx_buf[0] = cpu_to_be16(command);
/* build spi ring message */
st->ring_xfer[0].tx_buf = &st->tx_buf[0];
st->ring_xfer[0].len = 2;
st->ring_xfer[0].cs_change = 1;
st->ring_xfer[1].tx_buf = &st->tx_buf[1];
st->ring_xfer[1].len = 2;
st->ring_xfer[1].cs_change = 1;
spi_message_init(&st->ring_msg);
spi_message_add_tail(&st->ring_xfer[0], &st->ring_msg);
spi_message_add_tail(&st->ring_xfer[1], &st->ring_msg);
for (i = 0; i < scan_count; i++) {
st->ring_xfer[i + 2].rx_buf = &st->rx_buf[i];
st->ring_xfer[i + 2].len = 2;
st->ring_xfer[i + 2].cs_change = 1;
spi_message_add_tail(&st->ring_xfer[i + 2], &st->ring_msg);
}
/* make sure last transfer cs_change is not set */
st->ring_xfer[i + 1].cs_change = 0;
return 0;
}