staging: iio: ad7192: implement IIO_CHAN_INFO_SAMP_FREQ

This driver predates the availability of IIO_CHAN_INFO_SAMP_FREQ
attribute wherein usage has some advantages like it can be accessed by
in-kernel consumers as well as reduces the code size.

Therefore, use IIO_CHAN_INFO_SAMP_FREQ to implement the
sampling_frequency attribute instead of using IIO_DEV_ATTR_SAMP_FREQ()
macro.

Move code from the functions associated with IIO_DEV_ATTR_SAMP_FREQ()
into respective read and write hooks with the mask set to
IIO_CHAN_INFO_SAMP_FREQ.

Signed-off-by: Eva Rachel Retuya <eraretuya@gmail.com>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

diff --git a/drivers/staging/iio/adc/ad7192.c b/drivers/staging/iio/adc/ad7192.c
index 1cf6b79..bfa12ce 100644 (file)
--- a/drivers/staging/iio/adc/ad7192.c
+++ b/drivers/staging/iio/adc/ad7192.c
@@ -322,57 +322,6 @@ out:
        return ret;
 }
 
-static ssize_t ad7192_read_frequency(struct device *dev,
-                                    struct device_attribute *attr,
-                                    char *buf)
-{
-       struct iio_dev *indio_dev = dev_to_iio_dev(dev);
-       struct ad7192_state *st = iio_priv(indio_dev);
-
-       return sprintf(buf, "%d\n", st->mclk /
-                       (st->f_order * 1024 * AD7192_MODE_RATE(st->mode)));
-}
-
-static ssize_t ad7192_write_frequency(struct device *dev,
-                                     struct device_attribute *attr,
-                                     const char *buf,
-                                     size_t len)
-{
-       struct iio_dev *indio_dev = dev_to_iio_dev(dev);
-       struct ad7192_state *st = iio_priv(indio_dev);
-       unsigned long lval;
-       int div, ret;
-
-       ret = kstrtoul(buf, 10, &lval);
-       if (ret)
-               return ret;
-       if (lval == 0)
-               return -EINVAL;
-
-       ret = iio_device_claim_direct_mode(indio_dev);
-       if (ret)
-               return ret;
-
-       div = st->mclk / (lval * st->f_order * 1024);
-       if (div < 1 || div > 1023) {
-               ret = -EINVAL;
-               goto out;
-       }
-
-       st->mode &= ~AD7192_MODE_RATE(-1);
-       st->mode |= AD7192_MODE_RATE(div);
-       ad_sd_write_reg(&st->sd, AD7192_REG_MODE, 3, st->mode);
-
-out:
-       iio_device_release_direct_mode(indio_dev);
-
-       return ret ? ret : len;
-}
-
-static IIO_DEV_ATTR_SAMP_FREQ(S_IWUSR | S_IRUGO,
-               ad7192_read_frequency,
-               ad7192_write_frequency);
-
 static ssize_t
 ad7192_show_scale_available(struct device *dev,
                            struct device_attribute *attr, char *buf)
@@ -471,7 +420,6 @@ static IIO_DEVICE_ATTR(ac_excitation_en, S_IRUGO | S_IWUSR,
                       AD7192_REG_MODE);
 
 static struct attribute *ad7192_attributes[] = {
-       &iio_dev_attr_sampling_frequency.dev_attr.attr,
        &iio_dev_attr_in_v_m_v_scale_available.dev_attr.attr,
        &iio_dev_attr_in_voltage_scale_available.dev_attr.attr,
        &iio_dev_attr_bridge_switch_en.dev_attr.attr,
@@ -484,7 +432,6 @@ static const struct attribute_group ad7192_attribute_group = {
 };
 
 static struct attribute *ad7195_attributes[] = {
-       &iio_dev_attr_sampling_frequency.dev_attr.attr,
        &iio_dev_attr_in_v_m_v_scale_available.dev_attr.attr,
        &iio_dev_attr_in_voltage_scale_available.dev_attr.attr,
        &iio_dev_attr_bridge_switch_en.dev_attr.attr,
@@ -536,6 +483,10 @@ static int ad7192_read_raw(struct iio_dev *indio_dev,
                if (chan->type == IIO_TEMP)
                        *val -= 273 * ad7192_get_temp_scale(unipolar);
                return IIO_VAL_INT;
+       case IIO_CHAN_INFO_SAMP_FREQ:
+               *val = st->mclk /
+                       (st->f_order * 1024 * AD7192_MODE_RATE(st->mode));
+               return IIO_VAL_INT;
        }
 
        return -EINVAL;
@@ -548,7 +499,7 @@ static int ad7192_write_raw(struct iio_dev *indio_dev,
                            long mask)
 {
        struct ad7192_state *st = iio_priv(indio_dev);
-       int ret, i;
+       int ret, i, div;
        unsigned int tmp;
 
        ret = iio_device_claim_direct_mode(indio_dev);
@@ -572,6 +523,22 @@ static int ad7192_write_raw(struct iio_dev *indio_dev,
                                break;
                        }
                break;
+       case IIO_CHAN_INFO_SAMP_FREQ:
+               if (!val) {
+                       ret = -EINVAL;
+                       break;
+               }
+
+               div = st->mclk / (val * st->f_order * 1024);
+               if (div < 1 || div > 1023) {
+                       ret = -EINVAL;
+                       break;
+               }
+
+               st->mode &= ~AD7192_MODE_RATE(-1);
+               st->mode |= AD7192_MODE_RATE(div);
+               ad_sd_write_reg(&st->sd, AD7192_REG_MODE, 3, st->mode);
+               break;
        default:
                ret = -EINVAL;
        }
@@ -585,7 +552,14 @@ static int ad7192_write_raw_get_fmt(struct iio_dev *indio_dev,
                                    struct iio_chan_spec const *chan,
                                    long mask)
 {
-       return IIO_VAL_INT_PLUS_NANO;
+       switch (mask) {
+       case IIO_CHAN_INFO_SCALE:
+               return IIO_VAL_INT_PLUS_NANO;
+       case IIO_CHAN_INFO_SAMP_FREQ:
+               return IIO_VAL_INT;
+       default:
+               return -EINVAL;
+       }
 }
 
 static const struct iio_info ad7192_info = {

diff --git a/include/linux/iio/adc/ad_sigma_delta.h b/include/linux/iio/adc/ad_sigma_delta.h
index e7fdec4..5ba430c 100644 (file)
--- a/include/linux/iio/adc/ad_sigma_delta.h
+++ b/include/linux/iio/adc/ad_sigma_delta.h
@@ -136,6 +136,7 @@ int ad_sd_validate_trigger(struct iio_dev *indio_dev, struct iio_trigger *trig);
                .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | \
                        BIT(IIO_CHAN_INFO_OFFSET), \
                .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE), \
+               .info_mask_shared_by_all = BIT(IIO_CHAN_INFO_SAMP_FREQ), \
                .scan_index = (_si), \
                .scan_type = { \
                        .sign = 'u', \