iio: hid-sensors: Pressure: Raw read support

Added support for raw reading of channel. If the sensor is powered
off, it will turn on for reading value.
Signed-off-by: NSrinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
Signed-off-by: NJonathan Cameron <jic23@kernel.org>

drivers/iio/pressure/hid-sensor-press.c

@@ -21,6 +21,7 @@
 #include <linux/interrupt.h>
 #include <linux/irq.h>
 #include <linux/slab.h>
+#include <linux/delay.h>
 #include <linux/hid-sensor-hub.h>
 #include <linux/iio/iio.h>
 #include <linux/iio/sysfs.h>
@@ -79,6 +80,7 @@ static int press_read_raw(struct iio_dev *indio_dev,
 	u32 address;
 	int ret;
 	int ret_type;
+	s32 poll_value;
 
 	*val = 0;
 	*val2 = 0;
@@ -94,12 +96,23 @@ static int press_read_raw(struct iio_dev *indio_dev,
 			report_id = -1;
 			break;
 		}
-		if (report_id >= 0)
+		if (report_id >= 0) {
+			poll_value = hid_sensor_read_poll_value(
+					&press_state->common_attributes);
+			if (poll_value < 0)
+				return -EINVAL;
+			hid_sensor_power_state(&press_state->common_attributes,
+						true);
+
+			msleep_interruptible(poll_value * 2);
+
 			*val = sensor_hub_input_attr_get_raw_value(
 				press_state->common_attributes.hsdev,
 				HID_USAGE_SENSOR_PRESSURE, address,
 				report_id);
-		else {
+			hid_sensor_power_state(&press_state->common_attributes,
+						false);
+		} else {
 			*val = 0;
 			return -EINVAL;
 		}