iio: hid-sensors: Add api to get poll value

Added interface to get poll value in milli-seconds. This value is
changed by changing sampling frequency. This API allows clients
to wait for at least some poll milli seconds before reading a new sample.

Signed-off-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

1 files changed, 20 insertions, 0 deletions

diff --git a/drivers/iio/common/hid-sensors/hid-sensor-attributes.c b/drivers/iio/common/hid-sensors/hid-sensor-attributes.c
index e61b1faa1e06..372964635ccf 100644
--- a/drivers/iio/common/hid-sensors/hid-sensor-attributes.c
+++ b/drivers/iio/common/hid-sensors/hid-sensor-attributes.c
@@ -147,6 +147,26 @@ static u32 convert_to_vtf_format(int size, int exp, int val1, int val2)
         return value;
 }
 
+s32 hid_sensor_read_poll_value(struct hid_sensor_common *st)
+{
+        s32 value = 0;
+        int ret;
+
+        ret = sensor_hub_get_feature(st->hsdev,
+                st->poll.report_id,
+                st->poll.index, &value);
+
+        if (ret < 0 || value < 0) {
+                return -EINVAL;
+        } else {
+                if (st->poll.units == HID_USAGE_SENSOR_UNITS_SECOND)
+                        value = value * 1000;
+        }
+
+        return value;
+}
+EXPORT_SYMBOL(hid_sensor_read_poll_value);
+
 int hid_sensor_read_samp_freq_value(struct hid_sensor_common *st,
                                 int *val1, int *val2)
 {