firmware: arm_scpi: add support for 64-bit sensor values

SCPI specification version 1.1 extended the sensor from 32-bit to 64-bit
values in order to accommodate new sensor class with 64-bit requirements

Since the SCPI driver sets the higher 32-bit for older protocol version
to zeros, there's no need to explicitly check the SCPI protocol version
and the backward compatibility is maintainted.

Acked-by: Guenter Roeck <linux@roeck-us.net>
Reviewed-by: Punit Agrawal <punit.agrawal@arm.com>
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
diff --git a/drivers/firmware/arm_scpi.c b/drivers/firmware/arm_scpi.c
index c32ac6e..7e3e595 100644
--- a/drivers/firmware/arm_scpi.c
+++ b/drivers/firmware/arm_scpi.c
@@ -231,7 +231,8 @@
 };
 
 struct sensor_value {
-	__le32 val;
+	__le32 lo_val;
+	__le32 hi_val;
 } __packed;
 
 static struct scpi_drvinfo *scpi_info;
@@ -525,7 +526,7 @@
 	return ret;
 }
 
-int scpi_sensor_get_value(u16 sensor, u32 *val)
+int scpi_sensor_get_value(u16 sensor, u64 *val)
 {
 	__le16 id = cpu_to_le16(sensor);
 	struct sensor_value buf;
@@ -534,7 +535,8 @@
 	ret = scpi_send_message(SCPI_CMD_SENSOR_VALUE, &id, sizeof(id),
 				&buf, sizeof(buf));
 	if (!ret)
-		*val = le32_to_cpu(buf.val);
+		*val = (u64)le32_to_cpu(buf.hi_val) << 32 |
+			le32_to_cpu(buf.lo_val);
 
 	return ret;
 }