staging:iio:ad7298: Rework regulator handling

Rework the regulator handling of the driver to match more closely what we do in
other drivers. Make the regulator non-optional if a external reference is used.
Also dispose the option of specifying the reference voltage via platform data.

Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

diff --git a/drivers/staging/iio/adc/ad7298.h b/drivers/staging/iio/adc/ad7298.h
index 0ce9031..6523e01 100644 (file)
--- a/drivers/staging/iio/adc/ad7298.h
+++ b/drivers/staging/iio/adc/ad7298.h
@@ -26,19 +26,17 @@
 
 #define RES_MASK(bits) ((1 << (bits)) - 1)
 
-/*
- * TODO: struct ad7298_platform_data needs to go into include/linux/iio
- */
-
+/**
+ * struct ad7298_platform_data - Platform data for the ad7298 ADC driver
+ * @ext_ref: Whether to use an external reference voltage.
+ **/
 struct ad7298_platform_data {
-       /* External Vref voltage applied */
-       u16                             vref_mv;
+       bool ext_ref;
 };
 
 struct ad7298_state {
        struct spi_device               *spi;
        struct regulator                *reg;
-       u16                             int_vref_mv;
        unsigned                        ext_ref;
        struct spi_transfer             ring_xfer[10];
        struct spi_transfer             scan_single_xfer[3];

diff --git a/drivers/staging/iio/adc/ad7298_core.c b/drivers/staging/iio/adc/ad7298_core.c
index 67082ad..6dd696f 100644 (file)
--- a/drivers/staging/iio/adc/ad7298_core.c
+++ b/drivers/staging/iio/adc/ad7298_core.c
@@ -130,7 +130,7 @@ static int ad7298_read_raw(struct iio_dev *indio_dev,
 {
        int ret;
        struct ad7298_state *st = iio_priv(indio_dev);
-       unsigned int scale_uv;
+       int scale_mv;
 
        switch (m) {
        case IIO_CHAN_INFO_RAW:
@@ -155,10 +155,17 @@ static int ad7298_read_raw(struct iio_dev *indio_dev,
        case IIO_CHAN_INFO_SCALE:
                switch (chan->type) {
                case IIO_VOLTAGE:
-                       scale_uv = (st->int_vref_mv * 1000) >> AD7298_BITS;
-                       *val =  scale_uv / 1000;
-                       *val2 = (scale_uv % 1000) * 1000;
-                       return IIO_VAL_INT_PLUS_MICRO;
+                       if (st->ext_ref) {
+                               scale_mv = regulator_get_voltage(st->reg);
+                               if (scale_mv < 0)
+                                       return scale_mv;
+                               scale_mv /= 1000;
+                       } else {
+                               scale_mv = AD7298_INTREF_mV;
+                       }
+                       *val =  scale_mv;
+                       *val2 = chan->scan_type.realbits;
+                       return IIO_VAL_FRACTIONAL_LOG2;
                case IIO_TEMP:
                        *val =  1;
                        *val2 = 0;
@@ -180,16 +187,23 @@ static int __devinit ad7298_probe(struct spi_device *spi)
 {
        struct ad7298_platform_data *pdata = spi->dev.platform_data;
        struct ad7298_state *st;
-       int ret;
        struct iio_dev *indio_dev = iio_device_alloc(sizeof(*st));
+       int ret;
 
        if (indio_dev == NULL)
                return -ENOMEM;
 
        st = iio_priv(indio_dev);
 
-       st->reg = regulator_get(&spi->dev, "vcc");
-       if (!IS_ERR(st->reg)) {
+       if (pdata && pdata->ext_ref)
+               st->ext_ref = AD7298_EXTREF;
+
+       if (st->ext_ref) {
+               st->reg = regulator_get(&spi->dev, "vref");
+               if (IS_ERR(st->reg)) {
+                       ret = PTR_ERR(st->reg);
+                       goto error_free;
+               }
                ret = regulator_enable(st->reg);
                if (ret)
                        goto error_put_reg;
@@ -222,13 +236,6 @@ static int __devinit ad7298_probe(struct spi_device *spi)
        spi_message_add_tail(&st->scan_single_xfer[1], &st->scan_single_msg);
        spi_message_add_tail(&st->scan_single_xfer[2], &st->scan_single_msg);
 
-       if (pdata && pdata->vref_mv) {
-               st->int_vref_mv = pdata->vref_mv;
-               st->ext_ref = AD7298_EXTREF;
-       } else {
-               st->int_vref_mv = AD7298_INTREF_mV;
-       }
-
        ret = ad7298_register_ring_funcs_and_init(indio_dev);
        if (ret)
                goto error_disable_reg;
@@ -242,11 +249,12 @@ static int __devinit ad7298_probe(struct spi_device *spi)
 error_cleanup_ring:
        ad7298_ring_cleanup(indio_dev);
 error_disable_reg:
-       if (!IS_ERR(st->reg))
+       if (st->ext_ref)
                regulator_disable(st->reg);
 error_put_reg:
-       if (!IS_ERR(st->reg))
+       if (st->ext_ref)
                regulator_put(st->reg);
+error_free:
        iio_device_free(indio_dev);
 
        return ret;
@@ -259,7 +267,7 @@ static int __devexit ad7298_remove(struct spi_device *spi)
 
        iio_device_unregister(indio_dev);
        ad7298_ring_cleanup(indio_dev);
-       if (!IS_ERR(st->reg)) {
+       if (st->ext_ref) {
                regulator_disable(st->reg);
                regulator_put(st->reg);
        }