IIO: ADC: AD7476: Update timestamp handling

Add timestamp attributes.
Revise timestamp handling accordingly.
Preset timestamp generation.

Signed-off-by: Michael Hennerich <michael.hennerich@analog.com>
Acked-by: Jonathan Cameron <jic23@cam.ac.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

diff --git a/drivers/staging/iio/adc/ad7476.h b/drivers/staging/iio/adc/ad7476.h
index b51b49e4abd6089b1bf6afd603c7cc03e9aa0701..f917e9c3d54f64c3c9099f39b7826cb7b1717ac0 100644 (file)
--- a/drivers/staging/iio/adc/ad7476.h
+++ b/drivers/staging/iio/adc/ad7476.h
@@ -33,6 +33,7 @@ struct ad7476_state {
        struct regulator                *reg;
        struct work_struct              poll_work;
        atomic_t                        protect_ring;
+       size_t                          d_size;
        u16                             int_vref_mv;
        struct spi_transfer             xfer;
        struct spi_message              msg;

diff --git a/drivers/staging/iio/adc/ad7476_ring.c b/drivers/staging/iio/adc/ad7476_ring.c
index 85de14274ad739dc8a0e63cb7c28a198fd26be1c..1d654c86099de44cc4ae73906abdb0519d6d8289 100644 (file)
--- a/drivers/staging/iio/adc/ad7476_ring.c
+++ b/drivers/staging/iio/adc/ad7476_ring.c
@@ -26,6 +26,8 @@
 #include "ad7476.h"
 
 static IIO_SCAN_EL_C(in0, 0, 0, NULL);
+static IIO_SCAN_EL_TIMESTAMP(1);
+static IIO_CONST_ATTR_SCAN_EL_TYPE(timestamp, s, 64, 64);
 
 static ssize_t ad7476_show_type(struct device *dev,
                                struct device_attribute *attr,
@@ -44,6 +46,9 @@ static IIO_DEVICE_ATTR(in_type, S_IRUGO, ad7476_show_type, NULL, 0);
 static struct attribute *ad7476_scan_el_attrs[] = {
        &iio_scan_el_in0.dev_attr.attr,
        &iio_const_attr_in0_index.dev_attr.attr,
+       &iio_const_attr_timestamp_index.dev_attr.attr,
+       &iio_scan_el_timestamp.dev_attr.attr,
+       &iio_const_attr_timestamp_type.dev_attr.attr,
        &iio_dev_attr_in_type.dev_attr.attr,
        NULL,
 };
@@ -86,16 +91,21 @@ error_ret:
 static int ad7476_ring_preenable(struct iio_dev *indio_dev)
 {
        struct ad7476_state *st = indio_dev->dev_data;
-       size_t d_size;
+       struct iio_ring_buffer *ring = indio_dev->ring;
 
-       if (indio_dev->ring->access.set_bytes_per_datum) {
-               d_size = st->chip_info->storagebits / 8 + sizeof(s64);
-               if (d_size % 8)
-                       d_size += 8 - (d_size % 8);
-               indio_dev->ring->access.set_bytes_per_datum(indio_dev->ring,
-                                                           d_size);
+       st->d_size = ring->scan_count * st->chip_info->storagebits / 8;
+
+       if (ring->scan_timestamp) {
+               st->d_size += sizeof(s64);
+
+               if (st->d_size % sizeof(s64))
+                       st->d_size += sizeof(s64) - (st->d_size % sizeof(s64));
        }
 
+       if (indio_dev->ring->access.set_bytes_per_datum)
+               indio_dev->ring->access.set_bytes_per_datum(indio_dev->ring,
+                                                           st->d_size);
+
        return 0;
 }
 
@@ -131,18 +141,12 @@ static void ad7476_poll_bh_to_ring(struct work_struct *work_s)
        s64 time_ns;
        __u8 *rxbuf;
        int b_sent;
-       size_t d_size;
-
-       /* Ensure the timestamp is 8 byte aligned */
-       d_size = st->chip_info->storagebits / 8 + sizeof(s64);
-       if (d_size % sizeof(s64))
-               d_size += sizeof(s64) - (d_size % sizeof(s64));
 
        /* Ensure only one copy of this function running at a time */
        if (atomic_inc_return(&st->protect_ring) > 1)
                return;
 
-       rxbuf = kzalloc(d_size, GFP_KERNEL);
+       rxbuf = kzalloc(st->d_size, GFP_KERNEL);
        if (rxbuf == NULL)
                return;
 
@@ -152,7 +156,9 @@ static void ad7476_poll_bh_to_ring(struct work_struct *work_s)
 
        time_ns = iio_get_time_ns();
 
-       memcpy(rxbuf + d_size - sizeof(s64), &time_ns, sizeof(time_ns));
+       if (indio_dev->ring->scan_timestamp)
+               memcpy(rxbuf + st->d_size - sizeof(s64),
+                       &time_ns, sizeof(time_ns));
 
        indio_dev->ring->access.store_to(&sw_ring->buf, rxbuf, time_ns);
 done:
@@ -182,6 +188,7 @@ int ad7476_register_ring_funcs_and_init(struct iio_dev *indio_dev)
        indio_dev->ring->postenable = &iio_triggered_ring_postenable;
        indio_dev->ring->predisable = &iio_triggered_ring_predisable;
        indio_dev->ring->scan_el_attrs = &ad7476_scan_el_group;
+       indio_dev->ring->scan_timestamp = true;
 
        INIT_WORK(&st->poll_work, &ad7476_poll_bh_to_ring);