[PATCH 06/11] staging: iio: adc: ad7606: Use find_closest() macro

[Stefan Popa]

When looking for the available scale or oversampling ratio, it is better
to use the find_closest() macro. This simplifies the code and also does
not require an exact value to be entered from the user space.

Signed-off-by: Stefan Popa <stefan.p...@analog.com>
---
 drivers/staging/iio/adc/ad7606.c | 58 +++++++++++++++-------------------------
 1 file changed, 22 insertions(+), 36 deletions(-)

diff --git a/drivers/staging/iio/adc/ad7606.c b/drivers/staging/iio/adc/ad7606.c
index 13aeeec..0925379 100644
--- a/drivers/staging/iio/adc/ad7606.c
+++ b/drivers/staging/iio/adc/ad7606.c
@@ -16,6 +16,7 @@
 #include <linux/delay.h>
 #include <linux/sched.h>
 #include <linux/module.h>
+#include <linux/util_macros.h>
 
 #include <linux/iio/iio.h>
 #include <linux/iio/sysfs.h>
@@ -30,8 +31,12 @@
  * Scales are computed as 5000/32768 and 10000/32768 respectively,
  * so that when applied to the raw values they provide mV values
  */
-static const unsigned int scale_avail[2][2] = {
-       {0, 152588}, {0, 305176}
+static const unsigned int scale_avail[2] = {
+       152588, 305176
+};
+
+static const unsigned int ad7606_oversampling_avail[7] = {
+       1, 2, 4, 8, 16, 32, 64,
 };
 
 static int ad7606_reset(struct ad7606_state *st)
@@ -148,8 +153,8 @@ static int ad7606_read_raw(struct iio_dev *indio_dev,
                *val = (short)ret;
                return IIO_VAL_INT;
        case IIO_CHAN_INFO_SCALE:
-               *val = scale_avail[st->range][0];
-               *val2 = scale_avail[st->range][1];
+               *val = 0;
+               *val2 = scale_avail[st->range];
                return IIO_VAL_INT_PLUS_MICRO;
        case IIO_CHAN_INFO_OVERSAMPLING_RATIO:
                *val = st->oversampling;
@@ -165,8 +170,8 @@ static ssize_t in_voltage_scale_available_show(struct 
device *dev,
        int i, len = 0;
 
        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]);
+               len += scnprintf(buf + len, PAGE_SIZE - len, "0.%06u ",
+                                scale_avail[i]);
 
        buf[len - 1] = '\n';
 
@@ -175,18 +180,6 @@ static ssize_t in_voltage_scale_available_show(struct 
device *dev,
 
 static IIO_DEVICE_ATTR_RO(in_voltage_scale_available, 0);
 
-static int ad7606_oversampling_get_index(unsigned int val)
-{
-       unsigned char supported[] = {1, 2, 4, 8, 16, 32, 64};
-       int i;
-
-       for (i = 0; i < ARRAY_SIZE(supported); i++)
-               if (val == supported[i])
-                       return i;
-
-       return -EINVAL;
-}
-
 static int ad7606_write_raw(struct iio_dev *indio_dev,
                            struct iio_chan_spec const *chan,
                            int val,
@@ -195,36 +188,29 @@ static int ad7606_write_raw(struct iio_dev *indio_dev,
 {
        struct ad7606_state *st = iio_priv(indio_dev);
        DECLARE_BITMAP(values, 3);
-       int ret, i;
+       int i;
 
        switch (mask) {
        case IIO_CHAN_INFO_SCALE:
-               ret = -EINVAL;
                mutex_lock(&st->lock);
-               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;
-                       }
+               i = find_closest(val2, scale_avail, ARRAY_SIZE(scale_avail));
+               gpiod_set_value(st->gpio_range, i);
+               st->range = i;
                mutex_unlock(&st->lock);
 
-               return ret;
+               return 0;
        case IIO_CHAN_INFO_OVERSAMPLING_RATIO:
                if (val2)
                        return -EINVAL;
-               ret = ad7606_oversampling_get_index(val);
-               if (ret < 0)
-                       return ret;
+               i = find_closest(val, ad7606_oversampling_avail,
+                                ARRAY_SIZE(ad7606_oversampling_avail));
 
-               values[0] = ret;
+               values[0] = i;
 
                mutex_lock(&st->lock);
-               gpiod_set_array_value(3, st->gpio_os->desc, st->gpio_os->info,
-                                     values);
-               st->oversampling = val;
+               gpiod_set_array_value(ARRAY_SIZE(values), st->gpio_os->desc,
+                                     st->gpio_os->info, values);
+               st->oversampling = ad7606_oversampling_avail[i];
                mutex_unlock(&st->lock);
 
                return 0;
-- 
2.7.4