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authorLars-Peter Clausen <lars@metafoo.de>2013-03-04 19:30:00 +0000
committerJonathan Cameron <jic23@kernel.org>2013-03-17 20:16:40 +0000
commitecf6ca2539bc3a36a14685b743fd7376707958ab (patch)
treede64d99020fdb59a48faca742ec562bcbe1967dc /drivers/iio/adc/ad7923.c
parent135f06465d6842fdf1381f2610e27ff43e81f24d (diff)
downloadop-kernel-dev-ecf6ca2539bc3a36a14685b743fd7376707958ab.zip
op-kernel-dev-ecf6ca2539bc3a36a14685b743fd7376707958ab.tar.gz
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>
Diffstat (limited to 'drivers/iio/adc/ad7923.c')
-rw-r--r--drivers/iio/adc/ad7923.c60
1 files changed, 53 insertions, 7 deletions
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 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;
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