[PATCH v3 5/5] iio: mxs-lradc: add write_raw function to modify scale

From: Hector Palacios
Date: Mon Jul 22 2013 - 10:05:48 EST


Added write_raw function to manipulate the optional divider_by_two
through the scaling attribute out of the available scales.

Signed-off-by: Hector Palacios <hector.palacios@xxxxxxxx>
---
drivers/staging/iio/adc/mxs-lradc.c | 56 ++++++++++++++++++++++++++++++++++++-
1 file changed, 55 insertions(+), 1 deletion(-)

diff --git a/drivers/staging/iio/adc/mxs-lradc.c b/drivers/staging/iio/adc/mxs-lradc.c
index 5d332b1..4d3c7f5 100644
--- a/drivers/staging/iio/adc/mxs-lradc.c
+++ b/drivers/staging/iio/adc/mxs-lradc.c
@@ -213,6 +213,7 @@ struct mxs_lradc {
#define LRADC_CTRL1_LRADC_IRQ_OFFSET 0

#define LRADC_CTRL2 0x20
+#define LRADC_CTRL2_DIVIDE_BY_TWO_OFFSET 24
#define LRADC_CTRL2_TEMPSENSE_PWD (1 << 15)

#define LRADC_STATUS 0x40
@@ -320,7 +321,8 @@ static int mxs_lradc_read_raw(struct iio_dev *iio_dev,
break;
case IIO_CHAN_INFO_SCALE:
*val = lradc->vref_mv[chan->channel];
- *val2 = chan->scan_type.realbits;
+ *val2 = chan->scan_type.realbits -
+ lradc->is_divided[chan->channel];
ret = IIO_VAL_FRACTIONAL_LOG2;
break;
default:
@@ -333,6 +335,56 @@ static int mxs_lradc_read_raw(struct iio_dev *iio_dev,
return ret;
}

+static int mxs_lradc_write_raw(struct iio_dev *iio_dev,
+ const struct iio_chan_spec *chan,
+ int val, int val2, long m)
+{
+ struct mxs_lradc *lradc = iio_priv(iio_dev);
+ struct mxs_lradc_scale *scale_avail =
+ lradc->scale_avail[chan->channel];
+ int ret;
+
+ ret = mutex_trylock(&lradc->lock);
+ if (!ret)
+ return -EBUSY;
+
+ switch (m) {
+ case IIO_CHAN_INFO_SCALE:
+ ret = -EINVAL;
+ if (val == scale_avail[MXS_LRADC_DIV_DISABLED].integer &&
+ val2 == scale_avail[MXS_LRADC_DIV_DISABLED].nano) {
+ /* divider by two disabled */
+ writel(1 << LRADC_CTRL2_DIVIDE_BY_TWO_OFFSET,
+ lradc->base + LRADC_CTRL2 + STMP_OFFSET_REG_CLR);
+ lradc->is_divided[chan->channel] = 0;
+ ret = 0;
+ } else if (val == scale_avail[MXS_LRADC_DIV_ENABLED].integer &&
+ val2 == scale_avail[MXS_LRADC_DIV_ENABLED].nano) {
+ /* divider by two enabled */
+ writel(1 << LRADC_CTRL2_DIVIDE_BY_TWO_OFFSET,
+ lradc->base + LRADC_CTRL2 + STMP_OFFSET_REG_SET);
+ lradc->is_divided[chan->channel] = 1;
+ ret = 0;
+ }
+
+ break;
+ default:
+ ret = -EINVAL;
+ break;
+ }
+
+ mutex_unlock(&lradc->lock);
+
+ return ret;
+}
+
+static int mxs_lradc_write_raw_get_fmt(struct iio_dev *iio_dev,
+ const struct iio_chan_spec *chan,
+ long m)
+{
+ return IIO_VAL_INT_PLUS_NANO;
+}
+
static ssize_t mxs_lradc_show_scale_available_ch(struct device *dev,
struct device_attribute *attr,
char *buf,
@@ -410,6 +462,8 @@ static const struct attribute_group mxs_lradc_attribute_group = {
static const struct iio_info mxs_lradc_iio_info = {
.driver_module = THIS_MODULE,
.read_raw = mxs_lradc_read_raw,
+ .write_raw = mxs_lradc_write_raw,
+ .write_raw_get_fmt = mxs_lradc_write_raw_get_fmt,
.attrs = &mxs_lradc_attribute_group,
};

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