iio:dac:m62332: use dynamic scale

Some regulators can supply multiple voltages. To take changing voltages
into account, the scale needs to be calculated on every read access.

Signed-off-by: Hartmut Knaack <knaack.h@gmx.de>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

diff --git a/drivers/iio/dac/m62332.c b/drivers/iio/dac/m62332.c
index fdb3e04..76e8b04 100644 (file)
--- a/drivers/iio/dac/m62332.c
+++ b/drivers/iio/dac/m62332.c
@@ -31,7 +31,6 @@
 
 struct m62332_data {
        struct i2c_client       *client;
-       u16                     vref_mv;
        struct regulator        *vcc;
        struct mutex            mutex;
        u8                      raw[M62332_CHANNELS];
@@ -89,11 +88,16 @@ static int m62332_read_raw(struct iio_dev *indio_dev,
                           long mask)
 {
        struct m62332_data *data = iio_priv(indio_dev);
+       int ret;
 
        switch (mask) {
        case IIO_CHAN_INFO_SCALE:
                /* Corresponds to Vref / 2^(bits) */
-               *val = data->vref_mv;
+               ret = regulator_get_voltage(data->vcc);
+               if (ret < 0)
+                       return ret;
+
+               *val = ret / 1000; /* mV */
                *val2 = 8;
 
                return IIO_VAL_FRACTIONAL_LOG2;
@@ -218,11 +222,6 @@ static int m62332_probe(struct i2c_client *client,
        indio_dev->modes = INDIO_DIRECT_MODE;
        indio_dev->info = &m62332_info;
 
-       ret = regulator_get_voltage(data->vcc);
-       if (ret < 0)
-               return ret;
-       data->vref_mv = ret / 1000; /* mV */
-
        ret = iio_map_array_register(indio_dev, client->dev.platform_data);
        if (ret < 0)
                return ret;