iio:ad7923: Implement scale reporting

[deliverable/linux.git] / drivers / iio / adc / ad7923.c

diff --git a/drivers/iio/adc/ad7923.c b/drivers/iio/adc/ad7923.c
index 36eee248a9f6bddda205905c1ef8a5884221cb32..11ccc42b25a6014b8523493036b201c6a19eb131 100644 (file)
--- a/drivers/iio/adc/ad7923.c
+++ b/drivers/iio/adc/ad7923.c
@@ -12,6 +12,7 @@
 #include <linux/slab.h>
 #include <linux/sysfs.h>
 #include <linux/spi/spi.h>
+#include <linux/regulator/consumer.h>
 #include <linux/err.h>
 #include <linux/delay.h>
 #include <linux/module.h>
@@ -56,6 +57,11 @@ struct ad7923_state {
        struct spi_transfer             scan_single_xfer[2];
        struct spi_message              ring_msg;
        struct spi_message              scan_single_msg;
+
+       struct regulator                *reg;
+
+       unsigned int                    settings;
+
        /*
         * DMA (thus cache coherency maintenance) requires the
         * transfer buffers to live in their own cache lines.
@@ -100,10 +106,9 @@ static int ad7923_update_scan_mode(struct iio_dev *indio_dev,
 
        len = 0;
        for_each_set_bit(i, active_scan_mask, AD7923_MAX_CHAN) {
-               cmd = AD7923_WRITE_CR | AD7923_CODING | AD7923_RANGE |
-                       AD7923_PM_MODE_WRITE(AD7923_PM_MODE_OPS) |
+               cmd = AD7923_WRITE_CR | AD7923_CHANNEL_WRITE(i) |
                        AD7923_SEQUENCE_WRITE(AD7923_SEQUENCE_OFF) |
-                       AD7923_CHANNEL_WRITE(i);
+                       st->settings;
                cmd <<= AD7923_SHIFT_REGISTER;
                st->tx_buf[len++] = cpu_to_be16(cmd);
        }
@@ -163,9 +168,9 @@ static int ad7923_scan_direct(struct ad7923_state *st, unsigned ch)
 {
        int ret, cmd;
 
-       cmd = AD7923_WRITE_CR | AD7923_PM_MODE_WRITE(AD7923_PM_MODE_OPS) |
-               AD7923_SEQUENCE_WRITE(AD7923_SEQUENCE_OFF) | AD7923_CODING |
-               AD7923_CHANNEL_WRITE(ch) | AD7923_RANGE;
+       cmd = AD7923_WRITE_CR | AD7923_CHANNEL_WRITE(ch) |
+               AD7923_SEQUENCE_WRITE(AD7923_SEQUENCE_OFF) |
+               st->settings;
        cmd <<= AD7923_SHIFT_REGISTER;
        st->tx_buf[0] = cpu_to_be16(cmd);
 
@@ -176,6 +181,22 @@ static int ad7923_scan_direct(struct ad7923_state *st, unsigned ch)
        return be16_to_cpu(st->rx_buf[0]);
 }
 
+static int ad7923_get_range(struct ad7923_state *st)
+{
+       int vref;
+
+       vref = regulator_get_voltage(st->reg);
+       if (vref < 0)
+               return vref;
+
+       vref /= 1000;
+
+       if (!(st->settings & AD7923_RANGE))
+               vref *= 2;
+
+       return vref;
+}
+
 static int ad7923_read_raw(struct iio_dev *indio_dev,
                           struct iio_chan_spec const *chan,
                           int *val,
@@ -203,6 +224,13 @@ static int ad7923_read_raw(struct iio_dev *indio_dev,
                        return -EIO;
 
                return IIO_VAL_INT;
+       case IIO_CHAN_INFO_SCALE:
+               ret = ad7923_get_range(st);
+               if (ret < 0)
+                       return ret;
+               *val = ret;
+               *val2 = chan->scan_type.realbits;
+               return IIO_VAL_FRACTIONAL_LOG2;
        }
        return -EINVAL;
 }
@@ -227,6 +255,8 @@ static int ad7923_probe(struct spi_device *spi)
        spi_set_drvdata(spi, indio_dev);
 
        st->spi = spi;
+       st->settings = AD7923_CODING | AD7923_RANGE |
+                       AD7923_PM_MODE_WRITE(AD7923_PM_MODE_OPS);
 
        indio_dev->name = spi_get_device_id(spi)->name;
        indio_dev->dev.parent = &spi->dev;
@@ -247,10 +277,19 @@ static int ad7923_probe(struct spi_device *spi)
        spi_message_add_tail(&st->scan_single_xfer[0], &st->scan_single_msg);
        spi_message_add_tail(&st->scan_single_xfer[1], &st->scan_single_msg);
 
+       st->reg = regulator_get(&spi->dev, "refin");
+       if (IS_ERR(st->reg)) {
+               ret = PTR_ERR(st->reg);
+               goto error_free;
+       }
+       ret = regulator_enable(st->reg);
+       if (ret)
+               goto error_put_reg;
+
        ret = iio_triggered_buffer_setup(indio_dev, NULL,
                        &ad7923_trigger_handler, NULL);
        if (ret)
-               goto error_free;
+               goto error_disable_reg;
 
        ret = iio_device_register(indio_dev);
        if (ret)
@@ -260,6 +299,10 @@ static int ad7923_probe(struct spi_device *spi)
 
 error_cleanup_ring:
        iio_triggered_buffer_cleanup(indio_dev);
+error_disable_reg:
+       regulator_disable(st->reg);
+error_put_reg:
+       regulator_put(st->reg);
 error_free:
        iio_device_free(indio_dev);
 
@@ -269,9 +312,12 @@ error_free:
 static int ad7923_remove(struct spi_device *spi)
 {
        struct iio_dev *indio_dev = spi_get_drvdata(spi);
+       struct ad7923_state *st = iio_priv(indio_dev);
 
        iio_device_unregister(indio_dev);
        iio_triggered_buffer_cleanup(indio_dev);
+       regulator_disable(st->reg);
+       regulator_put(st->reg);
        iio_device_free(indio_dev);
 
        return 0;