iio: adc: ad7124: Shift to dynamic allocation for channel configuration

This patch changes the channel configuration member of the device
structure from a fixed size array to a dynamic allocated one with a size
equal to the number of channels specified in the device tree. This will
ensure a more flexibility for compatible devices.

Ex. ad7124-4 - can have 4 differential or 8 pseudo-differential channels
ad7124-8 - can have 8 differential or 16 pseudo-differential channels

Also the device can suspport any other combination of differential and
pseudo-differential channels base on the physical number of inputs
available.

Signed-off-by: Mircea Caprioru <mircea.caprioru@analog.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

diff --git a/drivers/iio/adc/ad7124.c b/drivers/iio/adc/ad7124.c
index ab52c5e..edc6f1c 100644 (file)
--- a/drivers/iio/adc/ad7124.c
+++ b/drivers/iio/adc/ad7124.c
@@ -121,7 +121,7 @@ struct ad7124_channel_config {
 struct ad7124_state {
        const struct ad7124_chip_info *chip_info;
        struct ad_sigma_delta sd;
-       struct ad7124_channel_config channel_config[4];
+       struct ad7124_channel_config *channel_config;
        struct regulator *vref[4];
        struct clk *mclk;
        unsigned int adc_control;
@@ -439,6 +439,7 @@ static int ad7124_of_parse_channel_config(struct iio_dev *indio_dev,
        struct ad7124_state *st = iio_priv(indio_dev);
        struct device_node *child;
        struct iio_chan_spec *chan;
+       struct ad7124_channel_config *chan_config;
        unsigned int ain[2], channel = 0, tmp;
        int ret;
 
@@ -453,8 +454,14 @@ static int ad7124_of_parse_channel_config(struct iio_dev *indio_dev,
        if (!chan)
                return -ENOMEM;
 
+       chan_config = devm_kcalloc(indio_dev->dev.parent, st->num_channels,
+                                  sizeof(*chan_config), GFP_KERNEL);
+       if (!chan_config)
+               return -ENOMEM;
+
        indio_dev->channels = chan;
        indio_dev->num_channels = st->num_channels;
+       st->channel_config = chan_config;
 
        for_each_available_child_of_node(np, child) {
                ret = of_property_read_u32(child, "reg", &channel);