staging:iio:accel:sca3000 Add write support to the low pass filter control

Also includes an available attribute.  The ordering of values appears
a bit random, but as the ABI doesn't specify this and we already have
both rising and falling lists I think this is fine.

Signed-off-by: Jonathan Cameron <jic23@kernel.org>
Reviewed-by: Lars-Peter Clausen <lars@metafoo.de>

diff --git a/drivers/staging/iio/accel/sca3000.c b/drivers/staging/iio/accel/sca3000.c
index b5dc40523bb5b7bc5eac965fb1d7e3a9fcbb5d08..f5ced157ead97fd9bbcb3d400bd1f2a1d785fd9e 100644 (file)
--- a/drivers/staging/iio/accel/sca3000.c
+++ b/drivers/staging/iio/accel/sca3000.c
@@ -433,6 +433,26 @@ error_ret:
        return ret ? ret : len;
 }
 
+static ssize_t
+sca3000_show_available_3db_freqs(struct device *dev,
+                                struct device_attribute *attr,
+                                char *buf)
+{
+       struct iio_dev *indio_dev = dev_to_iio_dev(dev);
+       struct sca3000_state *st = iio_priv(indio_dev);
+       int len;
+
+       len = sprintf(buf, "%d", st->info->measurement_mode_3db_freq);
+       if (st->info->option_mode_1)
+               len += sprintf(buf + len, " %d",
+                              st->info->option_mode_1_3db_freq);
+       if (st->info->option_mode_2)
+               len += sprintf(buf + len, " %d",
+                              st->info->option_mode_2_3db_freq);
+       len += sprintf(buf + len, "\n");
+
+       return len;
+}
 /**
  * sca3000_show_available_measurement_modes() display available modes
  *
@@ -571,6 +591,9 @@ static IIO_DEVICE_ATTR(measurement_mode, S_IRUGO | S_IWUSR,
                       sca3000_store_measurement_mode,
                       0);
 
+static IIO_DEVICE_ATTR(in_accel_filter_low_pass_3db_frequency_available,
+                      S_IRUGO, sca3000_show_available_3db_freqs,
+                      NULL, 0);
 /* More standard attributes */
 
 static IIO_DEVICE_ATTR(revision, S_IRUGO, sca3000_show_rev, NULL, 0);
@@ -779,6 +802,31 @@ static int sca3000_read_3db_freq(struct sca3000_state *st, int *val)
        }
 }
 
+static int sca3000_write_3db_freq(struct sca3000_state *st, int val)
+{
+       int ret;
+       int mode;
+
+       if (val == st->info->measurement_mode_3db_freq)
+               mode = SCA3000_REG_MODE_MEAS_MODE_NORMAL;
+       else if (st->info->option_mode_1 &&
+                (val == st->info->option_mode_1_3db_freq))
+               mode = SCA3000_REG_MODE_MEAS_MODE_OP_1;
+       else if (st->info->option_mode_2 &&
+                (val == st->info->option_mode_2_3db_freq))
+               mode = SCA3000_REG_MODE_MEAS_MODE_OP_2;
+       else
+               return -EINVAL;
+       ret = sca3000_read_data_short(st, SCA3000_REG_MODE_ADDR, 1);
+       if (ret)
+               return ret;
+
+       st->rx[0] &= ~SCA3000_REG_MODE_MODE_MASK;
+       st->rx[0] |= (mode & SCA3000_REG_MODE_MODE_MASK);
+
+       return sca3000_write_reg(st, SCA3000_REG_MODE_ADDR, st->rx[0]);
+}
+
 static int sca3000_read_raw(struct iio_dev *indio_dev,
                            struct iio_chan_spec const *chan,
                            int *val,
@@ -861,6 +909,12 @@ static int sca3000_write_raw(struct iio_dev *indio_dev,
                ret = write_raw_samp_freq(st, val);
                mutex_unlock(&st->lock);
                return ret;
+       case IIO_CHAN_INFO_LOW_PASS_FILTER_3DB_FREQUENCY:
+               if (val2)
+                       return -EINVAL;
+               mutex_lock(&st->lock);
+               ret = sca3000_write_3db_freq(st, val);
+               mutex_unlock(&st->lock);
        default:
                return -EINVAL;
        }
@@ -1007,6 +1061,7 @@ static struct attribute *sca3000_attributes[] = {
        &iio_dev_attr_revision.dev_attr.attr,
        &iio_dev_attr_measurement_mode_available.dev_attr.attr,
        &iio_dev_attr_measurement_mode.dev_attr.attr,
+       &iio_dev_attr_in_accel_filter_low_pass_3db_frequency_available.dev_attr.attr,
        &iio_dev_attr_sampling_frequency_available.dev_attr.attr,
        NULL,
 };