iio: adc: ad4170-4: Add timestamp channel

Add timestamp channel allowing to record the moment at which ADC samples
are captured in buffered read mode.

Signed-off-by: Marcelo Schmitt <marcelo.schmitt@analog.com>
Link: https://patch.msgid.link/e0af7e5424898bee0f3edfbb017133624efc169d.1751895245.git.marcelo.schmitt@analog.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

diff --git a/drivers/iio/adc/ad4170-4.c b/drivers/iio/adc/ad4170-4.c
index 738f373944023040147eb89e05814f3b51f1dcb7..30ae667a252c924573df12bee6b3bd3e3c9ff509 100644 (file)
--- a/drivers/iio/adc/ad4170-4.c
+++ b/drivers/iio/adc/ad4170-4.c
@@ -138,6 +138,7 @@
 
 #define AD4170_NUM_ANALOG_PINS                         9
 #define AD4170_MAX_ADC_CHANNELS                                16
+#define AD4170_MAX_IIO_CHANNELS                                (AD4170_MAX_ADC_CHANNELS + 1)
 #define AD4170_MAX_ANALOG_PINS                         8
 #define AD4170_MAX_SETUPS                              8
 #define AD4170_INVALID_SETUP                           9
@@ -334,7 +335,7 @@ struct ad4170_state {
        struct ad4170_setup_info setup_infos[AD4170_MAX_SETUPS];
        struct ad4170_chan_info chan_infos[AD4170_MAX_ADC_CHANNELS];
        struct completion completion;
-       struct iio_chan_spec chans[AD4170_MAX_ADC_CHANNELS];
+       struct iio_chan_spec chans[AD4170_MAX_IIO_CHANNELS];
        struct spi_device *spi;
        struct regmap *regmap;
        int sps_tbl[ARRAY_SIZE(ad4170_filt_names)][AD4170_MAX_FS_TBL_SIZE][2];
@@ -1633,6 +1634,12 @@ static int ad4170_parse_channels(struct iio_dev *indio_dev)
                        return ret;
        }
 
+       /* Add timestamp channel */
+       struct iio_chan_spec ts_chan = IIO_CHAN_SOFT_TIMESTAMP(chan_num);
+
+       st->chans[chan_num] = ts_chan;
+       num_channels = num_channels + 1;
+
        indio_dev->num_channels = num_channels;
        indio_dev->channels = st->chans;
 
@@ -1693,6 +1700,9 @@ static int ad4170_initial_config(struct iio_dev *indio_dev)
                unsigned int val;
 
                chan = &indio_dev->channels[i];
+               if (chan->type == IIO_TIMESTAMP)
+                       continue;
+
                chan_info = &st->chan_infos[chan->address];
 
                setup = &chan_info->setup;
@@ -1812,6 +1822,9 @@ static int ad4170_buffer_predisable(struct iio_dev *indio_dev)
         * channels will be read.
         */
        for (i = 0; i < indio_dev->num_channels; i++) {
+               if (indio_dev->channels[i].type == IIO_TIMESTAMP)
+                       continue;
+
                ret = ad4170_set_channel_enable(st, i, false);
                if (ret)
                        return ret;
@@ -1863,7 +1876,9 @@ static irqreturn_t ad4170_trigger_handler(int irq, void *p)
                memcpy(&st->bounce_buffer[i++], st->rx_buf, ARRAY_SIZE(st->rx_buf));
        }
 
-       iio_push_to_buffers(indio_dev, st->bounce_buffer);
+       iio_push_to_buffers_with_ts(indio_dev, st->bounce_buffer,
+                                   sizeof(st->bounce_buffer),
+                                   iio_get_time_ns(indio_dev));
 err_out:
        iio_trigger_notify_done(indio_dev->trig);
        return IRQ_HANDLED;