Both the periodic buffer based and one-shot sysfs based capture methods
share a large portion of their code. Factor this out into a common helper
function.
Also provide a comment that better explains in more detail what is going on
in the capture function.
Signed-off-by: Lars-Peter Clausen <lars@xxxxxxxxxx>
---
drivers/staging/iio/adc/ad7606.h | 1 +
drivers/staging/iio/adc/ad7606_core.c | 58 ++++++++++++++++++++++-------------
drivers/staging/iio/adc/ad7606_ring.c | 30 +++---------------
3 files changed, 41 insertions(+), 48 deletions(-)
diff --git a/drivers/staging/iio/adc/ad7606.h b/drivers/staging/iio/adc/ad7606.h
index 129f94e..2257bdb 100644
--- a/drivers/staging/iio/adc/ad7606.h
+++ b/drivers/staging/iio/adc/ad7606.h
@@ -84,6 +84,7 @@ struct iio_dev *ad7606_probe(struct device *dev, int irq,
const struct ad7606_bus_ops *bops);
int ad7606_remove(struct iio_dev *indio_dev, int irq);
int ad7606_reset(struct ad7606_state *st);
+int ad7606_read_samples(struct ad7606_state *st);
enum ad7606_supported_device_ids {
ID_AD7606_8,
diff --git a/drivers/staging/iio/adc/ad7606_core.c b/drivers/staging/iio/adc/ad7606_core.c
index 7c093e2..4ce103a 100644
--- a/drivers/staging/iio/adc/ad7606_core.c
+++ b/drivers/staging/iio/adc/ad7606_core.c
@@ -36,6 +36,39 @@ int ad7606_reset(struct ad7606_state *st)
return -ENODEV;
}
+int ad7606_read_samples(struct ad7606_state *st)
+{
+ unsigned int num = st->chip_info->num_channels;
+ u16 *data = st->data;
+ int ret;
+
+ /*
+ * The frstdata signal is set to high while and after reading the sample
+ * of the first channel and low for all other channels. This can be used
+ * to check that the incoming data is correctly aligned. During normal
+ * operation the data should never become unaligned, but some glitch or
+ * electrostatic discharge might cause an extra read or clock cycle.
+ * Monitoring the frstdata signal allows to recover from such failure
+ * situations.
+ */
+
+ if (gpio_is_valid(st->pdata->gpio_frstdata)) {
+ ret = st->bops->read_block(st->dev, 1, data);
+ if (ret)
+ return ret;
+
+ if (!gpio_get_value(st->pdata->gpio_frstdata)) {
+ ad7606_reset(st);
+ return -EIO;
+ }
+
+ data++;
+ num--;
+ }
+
+ return st->bops->read_block(st->dev, num, data);
+}
+
static int ad7606_scan_direct(struct iio_dev *indio_dev, unsigned int ch)
{
struct ad7606_state *st = iio_priv(indio_dev);
@@ -48,28 +81,9 @@ static int ad7606_scan_direct(struct iio_dev *indio_dev, unsigned int ch)
if (ret)
goto error_ret;
- if (gpio_is_valid(st->pdata->gpio_frstdata)) {
- ret = st->bops->read_block(st->dev, 1, st->data);
- if (ret)
- goto error_ret;
- if (!gpio_get_value(st->pdata->gpio_frstdata)) {
- /* This should never happen */
- ad7606_reset(st);
- ret = -EIO;
- goto error_ret;
- }
- ret = st->bops->read_block(st->dev,
- st->chip_info->num_channels - 1, &st->data[1]);
- if (ret)
- goto error_ret;
- } else {
- ret = st->bops->read_block(st->dev,
- st->chip_info->num_channels, st->data);
- if (ret)
- goto error_ret;
- }
-
- ret = st->data[ch];
+ ret = ad7606_read_samples(st);
+ if (ret == 0)
+ ret = st->data[ch];
error_ret:
gpio_set_value(st->pdata->gpio_convst, 0);
diff --git a/drivers/staging/iio/adc/ad7606_ring.c b/drivers/staging/iio/adc/ad7606_ring.c
index 7fa4ccc..b7bf0cf 100644
--- a/drivers/staging/iio/adc/ad7606_ring.c
+++ b/drivers/staging/iio/adc/ad7606_ring.c
@@ -48,33 +48,11 @@ static void ad7606_poll_bh_to_ring(struct work_struct *work_s)
struct iio_dev *indio_dev = iio_priv_to_dev(st);
int ret;
- if (gpio_is_valid(st->pdata->gpio_frstdata)) {
- ret = st->bops->read_block(st->dev, 1, st->data);
- if (ret)
- goto done;
- if (!gpio_get_value(st->pdata->gpio_frstdata)) {
- /* This should never happen. However
- * some signal glitch caused by bad PCB desgin or
- * electrostatic discharge, could cause an extra read
- * or clock. This allows recovery.
- */
- ad7606_reset(st);
- goto done;
- }
- ret = st->bops->read_block(st->dev,
- st->chip_info->num_channels - 1, st->data + 1);
- if (ret)
- goto done;
- } else {
- ret = st->bops->read_block(st->dev,
- st->chip_info->num_channels, st->data);
- if (ret)
- goto done;
- }
+ ret = ad7606_read_samples(st);
+ if (ret == 0)
+ iio_push_to_buffers_with_timestamp(indio_dev, st->data,
+ iio_get_time_ns(indio_dev));
- iio_push_to_buffers_with_timestamp(indio_dev, st->data,
- iio_get_time_ns(indio_dev));
-done:
gpio_set_value(st->pdata->gpio_convst, 0);
iio_trigger_notify_done(indio_dev->trig);
}
--
2.1.4
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