iio:ad7923: Implement scale reporting
The driver already claims to support scale reporting in its channel spec, but
doesn't actually implement this yet. This patch uses the regulator API to get
the reference voltage and calculates the scale based on that. The patch also
moves the global configuration bits into a field in the ad7923_state struct,
since depending on the RANGE bit, the range goes either from 0 to VREF or from 0
to 2 * VREF. So we need to know the setting of the RANGE bit when calculating
the scale.
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Cc: Patrick Vasseur <patrick.vasseur@c-s.fr>
Cc: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>
diff --git a/drivers/iio/adc/ad7923.c b/drivers/iio/adc/ad7923.c
index 36eee24..11ccc42 100644
--- 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 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 @@
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 @@
{
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 @@
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 @@
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 @@
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 @@
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 @@
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 @@
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;