staging: iio: cdc: ad7152: Implement IIO_CHAN_INFO_SAMP_FREQ attribute

Attributes that were once privately defined become standard with time
and hence a special global define is used. Hence update driver ad7152 to use
IIO_CHAN_INFO_SAMP_FREQ which is a global define instead of
IIO_DEV_ATTR_SAMP_FREQ.
Move functionality from IIO_DEV_ATTR_SAMP_FREQ attribute into
IIO_CHAN_INFO_SAMP_FREQ to implement the sampling_frequency attribute.
Modify ad7152_read_raw() and ad7152_write_raw() to allow reading and
writing the element as well. Also add a lock in the driver's private
data.

Signed-off-by: sayli karnik <karniksayli1995@gmail.com>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

diff --git a/drivers/staging/iio/cdc/ad7152.c b/drivers/staging/iio/cdc/ad7152.c
index 928f700..0203c81 100644 (file)
--- a/drivers/staging/iio/cdc/ad7152.c
+++ b/drivers/staging/iio/cdc/ad7152.c
@@ -167,63 +167,12 @@ static const unsigned char ad7152_filter_rate_table[][2] = {
        {200, 5 + 1}, {50, 20 + 1}, {20, 50 + 1}, {17, 60 + 1},
 };
 
-static ssize_t ad7152_show_filter_rate_setup(struct device *dev,
-               struct device_attribute *attr,
-               char *buf)
-{
-       struct iio_dev *indio_dev = dev_to_iio_dev(dev);
-       struct ad7152_chip_info *chip = iio_priv(indio_dev);
-
-       return sprintf(buf, "%d\n",
-                      ad7152_filter_rate_table[chip->filter_rate_setup][0]);
-}
-
-static ssize_t ad7152_store_filter_rate_setup(struct device *dev,
-               struct device_attribute *attr,
-               const char *buf,
-               size_t len)
-{
-       struct iio_dev *indio_dev = dev_to_iio_dev(dev);
-       struct ad7152_chip_info *chip = iio_priv(indio_dev);
-       u8 data;
-       int ret, i;
-
-       ret = kstrtou8(buf, 10, &data);
-       if (ret < 0)
-               return ret;
-
-       for (i = 0; i < ARRAY_SIZE(ad7152_filter_rate_table); i++)
-               if (data >= ad7152_filter_rate_table[i][0])
-                       break;
-
-       if (i >= ARRAY_SIZE(ad7152_filter_rate_table))
-               i = ARRAY_SIZE(ad7152_filter_rate_table) - 1;
-
-       mutex_lock(&indio_dev->mlock);
-       ret = i2c_smbus_write_byte_data(chip->client,
-                       AD7152_REG_CFG2, AD7152_CFG2_OSR(i));
-       if (ret < 0) {
-               mutex_unlock(&indio_dev->mlock);
-               return ret;
-       }
-
-       chip->filter_rate_setup = i;
-       mutex_unlock(&indio_dev->mlock);
-
-       return len;
-}
-
-static IIO_DEV_ATTR_SAMP_FREQ(S_IRUGO | S_IWUSR,
-               ad7152_show_filter_rate_setup,
-               ad7152_store_filter_rate_setup);
-
 static IIO_CONST_ATTR_SAMP_FREQ_AVAIL("200 50 20 17");
 
 static IIO_CONST_ATTR(in_capacitance_scale_available,
                      "0.000061050 0.000030525 0.000015263 0.000007631");
 
 static struct attribute *ad7152_attributes[] = {
-       &iio_dev_attr_sampling_frequency.dev_attr.attr,
        &iio_dev_attr_in_capacitance0_calibbias_calibration.dev_attr.attr,
        &iio_dev_attr_in_capacitance1_calibbias_calibration.dev_attr.attr,
        &iio_dev_attr_in_capacitance0_calibscale_calibration.dev_attr.attr,
@@ -249,6 +198,51 @@ static const int ad7152_scale_table[] = {
        30525, 7631, 15263, 61050
 };
 
+/**
+ * read_raw handler for IIO_CHAN_INFO_SAMP_FREQ
+ *
+ * lock must be held
+ **/
+static int ad7152_read_raw_samp_freq(struct device *dev, int *val)
+{
+       struct ad7152_chip_info *chip = iio_priv(dev_to_iio_dev(dev));
+
+       *val = ad7152_filter_rate_table[chip->filter_rate_setup][0];
+
+       return 0;
+}
+
+/**
+ * write_raw handler for IIO_CHAN_INFO_SAMP_FREQ
+ *
+ * lock must be held
+ **/
+static int ad7152_write_raw_samp_freq(struct device *dev, int val)
+{
+       struct iio_dev *indio_dev = dev_to_iio_dev(dev);
+       struct ad7152_chip_info *chip = iio_priv(indio_dev);
+       int ret, i;
+
+       for (i = 0; i < ARRAY_SIZE(ad7152_filter_rate_table); i++)
+               if (val >= ad7152_filter_rate_table[i][0])
+                       break;
+
+       if (i >= ARRAY_SIZE(ad7152_filter_rate_table))
+               i = ARRAY_SIZE(ad7152_filter_rate_table) - 1;
+
+       mutex_lock(&indio_dev->mlock);
+       ret = i2c_smbus_write_byte_data(chip->client,
+                                       AD7152_REG_CFG2, AD7152_CFG2_OSR(i));
+       if (ret < 0) {
+               mutex_unlock(&indio_dev->mlock);
+               return ret;
+       }
+
+       chip->filter_rate_setup = i;
+       mutex_unlock(&indio_dev->mlock);
+
+       return ret;
+}
 static int ad7152_write_raw(struct iio_dev *indio_dev,
                            struct iio_chan_spec const *chan,
                            int val,
@@ -311,6 +305,17 @@ static int ad7152_write_raw(struct iio_dev *indio_dev,
 
                ret = 0;
                break;
+       case IIO_CHAN_INFO_SAMP_FREQ:
+               if (val2) {
+                       ret = -EINVAL;
+                       goto out;
+               }
+               ret = ad7152_write_raw_samp_freq(&indio_dev->dev, val);
+               if (ret < 0)
+                       goto out;
+
+               ret = 0;
+               break;
        default:
                ret = -EINVAL;
        }
@@ -406,6 +411,13 @@ static int ad7152_read_raw(struct iio_dev *indio_dev,
 
                ret = IIO_VAL_INT_PLUS_NANO;
                break;
+       case IIO_CHAN_INFO_SAMP_FREQ:
+               ret = ad7152_read_raw_samp_freq(&indio_dev->dev, val);
+               if (ret < 0)
+                       goto out;
+
+               ret = IIO_VAL_INT;
+               break;
        default:
                ret = -EINVAL;
        }
@@ -443,6 +455,7 @@ static const struct iio_chan_spec ad7152_channels[] = {
                BIT(IIO_CHAN_INFO_CALIBSCALE) |
                BIT(IIO_CHAN_INFO_CALIBBIAS) |
                BIT(IIO_CHAN_INFO_SCALE),
+               .info_mask_shared_by_all = BIT(IIO_CHAN_INFO_SAMP_FREQ),
        }, {
                .type = IIO_CAPACITANCE,
                .differential = 1,
@@ -453,6 +466,7 @@ static const struct iio_chan_spec ad7152_channels[] = {
                BIT(IIO_CHAN_INFO_CALIBSCALE) |
                BIT(IIO_CHAN_INFO_CALIBBIAS) |
                BIT(IIO_CHAN_INFO_SCALE),
+               .info_mask_shared_by_all = BIT(IIO_CHAN_INFO_SAMP_FREQ),
        }, {
                .type = IIO_CAPACITANCE,
                .indexed = 1,
@@ -461,6 +475,7 @@ static const struct iio_chan_spec ad7152_channels[] = {
                BIT(IIO_CHAN_INFO_CALIBSCALE) |
                BIT(IIO_CHAN_INFO_CALIBBIAS) |
                BIT(IIO_CHAN_INFO_SCALE),
+               .info_mask_shared_by_all = BIT(IIO_CHAN_INFO_SAMP_FREQ),
        }, {
                .type = IIO_CAPACITANCE,
                .differential = 1,
@@ -471,6 +486,7 @@ static const struct iio_chan_spec ad7152_channels[] = {
                BIT(IIO_CHAN_INFO_CALIBSCALE) |
                BIT(IIO_CHAN_INFO_CALIBBIAS) |
                BIT(IIO_CHAN_INFO_SCALE),
+               .info_mask_shared_by_all = BIT(IIO_CHAN_INFO_SAMP_FREQ),
        }
 };