iio: adc: ti-ads7950: allow simultaneous use of buffer and direct mode
This modifies the TI ADS7950 A/DC driver to allow the simultaneous use of both the triggered buffer and reading channels directly (via in- kernel API or sysfs). The use case for this is on LEGO MINDSTORMS EV3. Two of the voltage channels are used in-kernel by a power supply driver, which reads the values using iio_read_channel_processed(). These channels are only read at a slow rate (<= 1Hz). However, we want to be able to read 12 other channels at the same time using the triggered buffer at a high rate (>= 100Hz). Signed-off-by: David Lechner <david@lechnology.com> Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
This commit is contained in:
Родитель
7d7209f0c4
Коммит
8134b613b0
|
@ -68,6 +68,9 @@ struct ti_ads7950_state {
|
|||
__be16 rx_buf[TI_ADS7950_MAX_CHAN + TI_ADS7950_TIMESTAMP_SIZE]
|
||||
____cacheline_aligned;
|
||||
__be16 tx_buf[TI_ADS7950_MAX_CHAN];
|
||||
__be16 single_tx;
|
||||
__be16 single_rx;
|
||||
|
||||
};
|
||||
|
||||
struct ti_ads7950_chip_info {
|
||||
|
@ -287,18 +290,26 @@ out:
|
|||
return IRQ_HANDLED;
|
||||
}
|
||||
|
||||
static int ti_ads7950_scan_direct(struct ti_ads7950_state *st, unsigned int ch)
|
||||
static int ti_ads7950_scan_direct(struct iio_dev *indio_dev, unsigned int ch)
|
||||
{
|
||||
struct ti_ads7950_state *st = iio_priv(indio_dev);
|
||||
int ret, cmd;
|
||||
|
||||
mutex_lock(&indio_dev->mlock);
|
||||
|
||||
cmd = TI_ADS7950_CR_WRITE | TI_ADS7950_CR_CHAN(ch) | st->settings;
|
||||
st->tx_buf[0] = cpu_to_be16(cmd);
|
||||
st->single_tx = cpu_to_be16(cmd);
|
||||
|
||||
ret = spi_sync(st->spi, &st->scan_single_msg);
|
||||
if (ret)
|
||||
return ret;
|
||||
goto out;
|
||||
|
||||
return be16_to_cpu(st->rx_buf[0]);
|
||||
ret = be16_to_cpu(st->single_rx);
|
||||
|
||||
out:
|
||||
mutex_unlock(&indio_dev->mlock);
|
||||
|
||||
return ret;
|
||||
}
|
||||
|
||||
static int ti_ads7950_get_range(struct ti_ads7950_state *st)
|
||||
|
@ -330,13 +341,7 @@ static int ti_ads7950_read_raw(struct iio_dev *indio_dev,
|
|||
|
||||
switch (m) {
|
||||
case IIO_CHAN_INFO_RAW:
|
||||
|
||||
ret = iio_device_claim_direct_mode(indio_dev);
|
||||
if (ret < 0)
|
||||
return ret;
|
||||
|
||||
ret = ti_ads7950_scan_direct(st, chan->address);
|
||||
iio_device_release_direct_mode(indio_dev);
|
||||
ret = ti_ads7950_scan_direct(indio_dev, chan->address);
|
||||
if (ret < 0)
|
||||
return ret;
|
||||
|
||||
|
@ -402,13 +407,13 @@ static int ti_ads7950_probe(struct spi_device *spi)
|
|||
* was read at the end of the first transfer.
|
||||
*/
|
||||
|
||||
st->scan_single_xfer[0].tx_buf = &st->tx_buf[0];
|
||||
st->scan_single_xfer[0].tx_buf = &st->single_tx;
|
||||
st->scan_single_xfer[0].len = 2;
|
||||
st->scan_single_xfer[0].cs_change = 1;
|
||||
st->scan_single_xfer[1].tx_buf = &st->tx_buf[0];
|
||||
st->scan_single_xfer[1].tx_buf = &st->single_tx;
|
||||
st->scan_single_xfer[1].len = 2;
|
||||
st->scan_single_xfer[1].cs_change = 1;
|
||||
st->scan_single_xfer[2].rx_buf = &st->rx_buf[0];
|
||||
st->scan_single_xfer[2].rx_buf = &st->single_rx;
|
||||
st->scan_single_xfer[2].len = 2;
|
||||
|
||||
spi_message_init_with_transfers(&st->scan_single_msg,
|
||||
|
|
Загрузка…
Ссылка в новой задаче