iio: adc: ad7380: prepare driver for single-ended parts support

ad738x family contains single-ended parts that have a 2:1 mux in front
of ADC, so the number of IIO channels is different from the number of
simultaneous channels that can be sampled.

To prepare the support for single-ended parts, introduce a new
num_simultaneous_channels variable. For currently supported parts,
num_simultaneous_channels is equal to num_channels minus 1 (the
timestamps channel)

Signed-off-by: Julien Stephan <jstephan@baylibre.com>
Reviewed-by: David Lechner <dlechner@baylibre.com>
Link: https://patch.msgid.link/20240731-ad7380-add-single-ended-chips-v2-4-cd63bf05744c@baylibre.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

diff --git a/drivers/iio/adc/ad7380.c b/drivers/iio/adc/ad7380.c
index 72fece383f72f6dcfe6069e6df873413015f510a..04cc1ef18131c959eab22791171a0711aa174c46 100644 (file)
--- a/drivers/iio/adc/ad7380.c
+++ b/drivers/iio/adc/ad7380.c
@@ -80,6 +80,7 @@ struct ad7380_chip_info {
        const char *name;
        const struct iio_chan_spec *channels;
        unsigned int num_channels;
+       unsigned int num_simult_channels;
        const char * const *vcm_supplies;
        unsigned int num_vcm_supplies;
        const unsigned long *available_scan_masks;
@@ -208,6 +209,7 @@ static const struct ad7380_chip_info ad7380_chip_info = {
        .name = "ad7380",
        .channels = ad7380_channels,
        .num_channels = ARRAY_SIZE(ad7380_channels),
+       .num_simult_channels = 2,
        .available_scan_masks = ad7380_2_channel_scan_masks,
        .timing_specs = &ad7380_timing,
 };
@@ -216,6 +218,7 @@ static const struct ad7380_chip_info ad7381_chip_info = {
        .name = "ad7381",
        .channels = ad7381_channels,
        .num_channels = ARRAY_SIZE(ad7381_channels),
+       .num_simult_channels = 2,
        .available_scan_masks = ad7380_2_channel_scan_masks,
        .timing_specs = &ad7380_timing,
 };
@@ -224,6 +227,7 @@ static const struct ad7380_chip_info ad7383_chip_info = {
        .name = "ad7383",
        .channels = ad7383_channels,
        .num_channels = ARRAY_SIZE(ad7383_channels),
+       .num_simult_channels = 2,
        .vcm_supplies = ad7380_2_channel_vcm_supplies,
        .num_vcm_supplies = ARRAY_SIZE(ad7380_2_channel_vcm_supplies),
        .available_scan_masks = ad7380_2_channel_scan_masks,
@@ -234,6 +238,7 @@ static const struct ad7380_chip_info ad7384_chip_info = {
        .name = "ad7384",
        .channels = ad7384_channels,
        .num_channels = ARRAY_SIZE(ad7384_channels),
+       .num_simult_channels = 2,
        .vcm_supplies = ad7380_2_channel_vcm_supplies,
        .num_vcm_supplies = ARRAY_SIZE(ad7380_2_channel_vcm_supplies),
        .available_scan_masks = ad7380_2_channel_scan_masks,
@@ -244,6 +249,7 @@ static const struct ad7380_chip_info ad7380_4_chip_info = {
        .name = "ad7380-4",
        .channels = ad7380_4_channels,
        .num_channels = ARRAY_SIZE(ad7380_4_channels),
+       .num_simult_channels = 4,
        .available_scan_masks = ad7380_4_channel_scan_masks,
        .timing_specs = &ad7380_4_timing,
 };
@@ -252,6 +258,7 @@ static const struct ad7380_chip_info ad7381_4_chip_info = {
        .name = "ad7381-4",
        .channels = ad7381_4_channels,
        .num_channels = ARRAY_SIZE(ad7381_4_channels),
+       .num_simult_channels = 4,
        .available_scan_masks = ad7380_4_channel_scan_masks,
        .timing_specs = &ad7380_4_timing,
 };
@@ -260,6 +267,7 @@ static const struct ad7380_chip_info ad7383_4_chip_info = {
        .name = "ad7383-4",
        .channels = ad7383_4_channels,
        .num_channels = ARRAY_SIZE(ad7383_4_channels),
+       .num_simult_channels = 4,
        .vcm_supplies = ad7380_4_channel_vcm_supplies,
        .num_vcm_supplies = ARRAY_SIZE(ad7380_4_channel_vcm_supplies),
        .available_scan_masks = ad7380_4_channel_scan_masks,
@@ -270,6 +278,7 @@ static const struct ad7380_chip_info ad7384_4_chip_info = {
        .name = "ad7384-4",
        .channels = ad7384_4_channels,
        .num_channels = ARRAY_SIZE(ad7384_4_channels),
+       .num_simult_channels = 4,
        .vcm_supplies = ad7380_4_channel_vcm_supplies,
        .num_vcm_supplies = ARRAY_SIZE(ad7380_4_channel_vcm_supplies),
        .available_scan_masks = ad7380_4_channel_scan_masks,
@@ -407,7 +416,7 @@ static void ad7380_update_xfers(struct ad7380_state *st,
         */
        st->xfer[1].bits_per_word = scan_type->realbits;
        st->xfer[1].len = BITS_TO_BYTES(scan_type->storagebits) *
-                         (st->chip_info->num_channels - 1);
+                         st->chip_info->num_simult_channels;
 }
 
 static int ad7380_triggered_buffer_preenable(struct iio_dev *indio_dev)