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Subject[PATCH v4] staging: iio: ad7606: replace range/range_available with corresponding scale
Date
Eliminate the non-standard attributes in_voltage_range and
in_voltage_range_available. Implement in_voltage_scale_available in place
of these attributes and update the SCALE accordingly. The array
scale_avail is introduced to hold the available scale values.

Signed-off-by: Eva Rachel Retuya <eraretuya@gmail.com>
---
Changes in v4:
* Drop the patch regarding move out of staging.
* Store the precomputed scales instead of computing them everytime.
* Switch from 9 digits accuracy to 6 digits, eliminates use of
write_raw_get_fmt().

drivers/staging/iio/adc/ad7606.c | 79 ++++++++++++++++++++--------------------
1 file changed, 39 insertions(+), 40 deletions(-)

diff --git a/drivers/staging/iio/adc/ad7606.c b/drivers/staging/iio/adc/ad7606.c
index 4531908..9dbfa64 100644
--- a/drivers/staging/iio/adc/ad7606.c
+++ b/drivers/staging/iio/adc/ad7606.c
@@ -26,6 +26,11 @@

#include "ad7606.h"

+/* Scales are computed as 2.5/2**16 and 5/2**16 respectively */
+static const unsigned int scale_avail[2][2] = {
+ {0, 38147}, {0, 76294}
+};
+
static int ad7606_reset(struct ad7606_state *st)
{
if (st->gpio_reset) {
@@ -151,9 +156,9 @@ static int ad7606_read_raw(struct iio_dev *indio_dev,
*val = (short)ret;
return IIO_VAL_INT;
case IIO_CHAN_INFO_SCALE:
- *val = st->range * 2;
- *val2 = st->chip_info->channels[0].scan_type.realbits;
- return IIO_VAL_FRACTIONAL_LOG2;
+ *val = scale_avail[st->range][0];
+ *val2 = scale_avail[st->range][1];
+ return IIO_VAL_INT_PLUS_MICRO;
case IIO_CHAN_INFO_OVERSAMPLING_RATIO:
*val = st->oversampling;
return IIO_VAL_INT;
@@ -161,42 +166,22 @@ static int ad7606_read_raw(struct iio_dev *indio_dev,
return -EINVAL;
}

-static ssize_t ad7606_show_range(struct device *dev,
- struct device_attribute *attr, char *buf)
-{
- struct iio_dev *indio_dev = dev_to_iio_dev(dev);
- struct ad7606_state *st = iio_priv(indio_dev);
-
- return sprintf(buf, "%u\n", st->range);
-}
-
-static ssize_t ad7606_store_range(struct device *dev,
- struct device_attribute *attr,
- const char *buf, size_t count)
+static ssize_t in_voltage_scale_available_show(struct device *dev,
+ struct device_attribute *attr,
+ char *buf)
{
- struct iio_dev *indio_dev = dev_to_iio_dev(dev);
- struct ad7606_state *st = iio_priv(indio_dev);
- unsigned long lval;
- int ret;
-
- ret = kstrtoul(buf, 10, &lval);
- if (ret)
- return ret;
+ int i, len = 0;

- if (!(lval == 5000 || lval == 10000))
- return -EINVAL;
+ for (i = 0; i < ARRAY_SIZE(scale_avail); i++)
+ len += scnprintf(buf + len, PAGE_SIZE - len, "%d.%06u ",
+ scale_avail[i][0], scale_avail[i][1]);

- mutex_lock(&indio_dev->mlock);
- gpiod_set_value(st->gpio_range, lval == 10000);
- st->range = lval;
- mutex_unlock(&indio_dev->mlock);
+ buf[len - 1] = '\n';

- return count;
+ return len;
}

-static IIO_DEVICE_ATTR(in_voltage_range, S_IRUGO | S_IWUSR,
- ad7606_show_range, ad7606_store_range, 0);
-static IIO_CONST_ATTR(in_voltage_range_available, "5000 10000");
+static IIO_DEVICE_ATTR_RO(in_voltage_scale_available, 0);

static int ad7606_oversampling_get_index(unsigned int val)
{
@@ -218,9 +203,23 @@ static int ad7606_write_raw(struct iio_dev *indio_dev,
{
struct ad7606_state *st = iio_priv(indio_dev);
int values[3];
- int ret;
+ int ret, i;

switch (mask) {
+ case IIO_CHAN_INFO_SCALE:
+ ret = -EINVAL;
+ mutex_lock(&indio_dev->mlock);
+ for (i = 0; i < ARRAY_SIZE(scale_avail); i++)
+ if (val2 == scale_avail[i][1]) {
+ gpiod_set_value(st->gpio_range, i);
+ st->range = i;
+
+ ret = 0;
+ break;
+ }
+ mutex_unlock(&indio_dev->mlock);
+
+ return ret;
case IIO_CHAN_INFO_OVERSAMPLING_RATIO:
if (val2)
return -EINVAL;
@@ -247,8 +246,7 @@ static int ad7606_write_raw(struct iio_dev *indio_dev,
static IIO_CONST_ATTR(oversampling_ratio_available, "1 2 4 8 16 32 64");

static struct attribute *ad7606_attributes_os_and_range[] = {
- &iio_dev_attr_in_voltage_range.dev_attr.attr,
- &iio_const_attr_in_voltage_range_available.dev_attr.attr,
+ &iio_dev_attr_in_voltage_scale_available.dev_attr.attr,
&iio_const_attr_oversampling_ratio_available.dev_attr.attr,
NULL,
};
@@ -267,8 +265,7 @@ static const struct attribute_group ad7606_attribute_group_os = {
};

static struct attribute *ad7606_attributes_range[] = {
- &iio_dev_attr_in_voltage_range.dev_attr.attr,
- &iio_const_attr_in_voltage_range_available.dev_attr.attr,
+ &iio_dev_attr_in_voltage_scale_available.dev_attr.attr,
NULL,
};

@@ -397,6 +394,7 @@ static const struct iio_info ad7606_info_os = {
static const struct iio_info ad7606_info_range = {
.driver_module = THIS_MODULE,
.read_raw = &ad7606_read_raw,
+ .write_raw = &ad7606_write_raw,
.attrs = &ad7606_attribute_group_range,
};

@@ -417,7 +415,8 @@ int ad7606_probe(struct device *dev, int irq, void __iomem *base_address,
st->dev = dev;
st->bops = bops;
st->base_address = base_address;
- st->range = 5000;
+ /* tied to logic low, analog input range is +/- 5V */
+ st->range = 0;
st->oversampling = 1;
INIT_WORK(&st->poll_work, &ad7606_poll_bh_to_ring);

@@ -525,7 +524,7 @@ static int ad7606_resume(struct device *dev)
struct ad7606_state *st = iio_priv(indio_dev);

if (st->gpio_standby) {
- gpiod_set_value(st->gpio_range, st->range == 10000);
+ gpiod_set_value(st->gpio_range, st->range);
gpiod_set_value(st->gpio_standby, 1);
ad7606_reset(st);
}
--
2.7.4
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