iio: adc: ad7944: use devm_regulator_get_enable_read_voltage

This makes use of the new devm_regulator_get_enable_read_voltage()
function to reduce boilerplate code.

Signed-off-by: David Lechner <dlechner@baylibre.com>
Reviewed-by: Nuno Sa <nuno.sa@analog.com>
Link: https://patch.msgid.link/20240612-iio-adc-ref-supply-refactor-v2-5-fa622e7354e9@baylibre.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

diff --git a/drivers/iio/adc/ad7944.c b/drivers/iio/adc/ad7944.c
index e2cb64cef476d1807211e5a85636d026082bf27e..4172723bb2ac9de17917975d1c66b1d5a0f44ba9 100644 (file)
--- a/drivers/iio/adc/ad7944.c
+++ b/drivers/iio/adc/ad7944.c
@@ -464,23 +464,17 @@ static const char * const ad7944_power_supplies[] = {
        "avdd", "dvdd", "bvdd", "vio"
 };
 
-static void ad7944_ref_disable(void *ref)
-{
-       regulator_disable(ref);
-}
-
 static int ad7944_probe(struct spi_device *spi)
 {
        const struct ad7944_chip_info *chip_info;
        struct device *dev = &spi->dev;
        struct iio_dev *indio_dev;
        struct ad7944_adc *adc;
-       bool have_refin = false;
-       struct regulator *ref;
+       bool have_refin;
        struct iio_chan_spec *chain_chan;
        unsigned long *chain_scan_masks;
        u32 n_chain_dev;
-       int ret;
+       int ret, ref_mv;
 
        indio_dev = devm_iio_device_alloc(dev, sizeof(*adc));
        if (!indio_dev)
@@ -531,47 +525,23 @@ static int ad7944_probe(struct spi_device *spi)
         * - external reference: REF is connected, REFIN is not connected
         */
 
-       ref = devm_regulator_get_optional(dev, "ref");
-       if (IS_ERR(ref)) {
-               if (PTR_ERR(ref) != -ENODEV)
-                       return dev_err_probe(dev, PTR_ERR(ref),
-                                            "failed to get REF supply\n");
+       ret = devm_regulator_get_enable_read_voltage(dev, "ref");
+       if (ret < 0 && ret != -ENODEV)
+               return dev_err_probe(dev, ret, "failed to get REF voltage\n");
 
-               ref = NULL;
-       }
+       ref_mv = ret == -ENODEV ? 0 : ret / 1000;
 
        ret = devm_regulator_get_enable_optional(dev, "refin");
-       if (ret == 0)
-               have_refin = true;
-       else if (ret != -ENODEV)
-               return dev_err_probe(dev, ret,
-                                    "failed to get and enable REFIN supply\n");
+       if (ret < 0 && ret != -ENODEV)
+               return dev_err_probe(dev, ret, "failed to get REFIN voltage\n");
+
+       have_refin = ret != -ENODEV;
 
-       if (have_refin && ref)
+       if (have_refin && ref_mv)
                return dev_err_probe(dev, -EINVAL,
                                     "cannot have both refin and ref supplies\n");
 
-       if (ref) {
-               ret = regulator_enable(ref);
-               if (ret)
-                       return dev_err_probe(dev, ret,
-                                            "failed to enable REF supply\n");
-
-               ret = devm_add_action_or_reset(dev, ad7944_ref_disable, ref);
-               if (ret)
-                       return ret;
-
-               ret = regulator_get_voltage(ref);
-               if (ret < 0)
-                       return dev_err_probe(dev, ret,
-                                            "failed to get REF voltage\n");
-
-               /* external reference */
-               adc->ref_mv = ret / 1000;
-       } else {
-               /* internal reference */
-               adc->ref_mv = AD7944_INTERNAL_REF_MV;
-       }
+       adc->ref_mv = ref_mv ?: AD7944_INTERNAL_REF_MV;
 
        adc->cnv = devm_gpiod_get_optional(dev, "cnv", GPIOD_OUT_LOW);
        if (IS_ERR(adc->cnv))