iio: adis16480: Fix scales factors

This patch fixes the scales for the gyroscope, accelerometer and
barometer. The pressure scale was just wrong. For the others, the scale
factors were not taking into account that a 32bit word is being read
from the device.

Fixes: 7abad106 ("iio: adis16480: Fix scale factors")
Fixes: 82e7a1b2 ("iio: imu: adis16480: Add support for ADIS1649x family of devices")
Signed-off-by: Nuno Sá <nuno.sa@analog.com>
Cc: <Stable@vger.kernel.org>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

drivers/iio/imu/adis16480.c

@@ -622,9 +622,13 @@ static int adis16480_read_raw(struct iio_dev *indio_dev,
 			*val2 = (st->chip_info->temp_scale % 1000) * 1000;
 			return IIO_VAL_INT_PLUS_MICRO;
 		case IIO_PRESSURE:
-			*val = 0;
-			*val2 = 4000; /* 40ubar = 0.004 kPa */
-			return IIO_VAL_INT_PLUS_MICRO;
+			/*
+			 * max scale is 1310 mbar
+			 * max raw value is 32767 shifted for 32bits
+			 */
+			*val = 131; /* 1310mbar = 131 kPa */
+			*val2 = 32767 << 16;
+			return IIO_VAL_FRACTIONAL;
 		default:
 			return -EINVAL;
 		}
@@ -785,13 +789,14 @@ static const struct adis16480_chip_info adis16480_chip_info[] = {
 		.channels = adis16485_channels,
 		.num_channels = ARRAY_SIZE(adis16485_channels),
 		/*
-		 * storing the value in rad/degree and the scale in degree
-		 * gives us the result in rad and better precession than
-		 * storing the scale directly in rad.
+		 * Typically we do IIO_RAD_TO_DEGREE in the denominator, which
+		 * is exactly the same as IIO_DEGREE_TO_RAD in numerator, since
+		 * it gives better approximation. However, in this case we
+		 * cannot do it since it would not fit in a 32bit variable.
 		 */
-		.gyro_max_val = IIO_RAD_TO_DEGREE(22887),
-		.gyro_max_scale = 300,
-		.accel_max_val = IIO_M_S_2_TO_G(21973),
+		.gyro_max_val = 22887 << 16,
+		.gyro_max_scale = IIO_DEGREE_TO_RAD(300),
+		.accel_max_val = IIO_M_S_2_TO_G(21973 << 16),
 		.accel_max_scale = 18,
 		.temp_scale = 5650, /* 5.65 milli degree Celsius */
 		.int_clk = 2460000,
@@ -801,9 +806,9 @@ static const struct adis16480_chip_info adis16480_chip_info[] = {
 	[ADIS16480] = {
 		.channels = adis16480_channels,
 		.num_channels = ARRAY_SIZE(adis16480_channels),
-		.gyro_max_val = IIO_RAD_TO_DEGREE(22500),
-		.gyro_max_scale = 450,
-		.accel_max_val = IIO_M_S_2_TO_G(12500),
+		.gyro_max_val = 22500 << 16,
+		.gyro_max_scale = IIO_DEGREE_TO_RAD(450),
+		.accel_max_val = IIO_M_S_2_TO_G(12500 << 16),
 		.accel_max_scale = 10,
 		.temp_scale = 5650, /* 5.65 milli degree Celsius */
 		.int_clk = 2460000,
@@ -813,9 +818,9 @@ static const struct adis16480_chip_info adis16480_chip_info[] = {
 	[ADIS16485] = {
 		.channels = adis16485_channels,
 		.num_channels = ARRAY_SIZE(adis16485_channels),
-		.gyro_max_val = IIO_RAD_TO_DEGREE(22500),
-		.gyro_max_scale = 450,
-		.accel_max_val = IIO_M_S_2_TO_G(20000),
+		.gyro_max_val = 22500 << 16,
+		.gyro_max_scale = IIO_DEGREE_TO_RAD(450),
+		.accel_max_val = IIO_M_S_2_TO_G(20000 << 16),
 		.accel_max_scale = 5,
 		.temp_scale = 5650, /* 5.65 milli degree Celsius */
 		.int_clk = 2460000,
@@ -825,9 +830,9 @@ static const struct adis16480_chip_info adis16480_chip_info[] = {
 	[ADIS16488] = {
 		.channels = adis16480_channels,
 		.num_channels = ARRAY_SIZE(adis16480_channels),
-		.gyro_max_val = IIO_RAD_TO_DEGREE(22500),
-		.gyro_max_scale = 450,
-		.accel_max_val = IIO_M_S_2_TO_G(22500),
+		.gyro_max_val = 22500 << 16,
+		.gyro_max_scale = IIO_DEGREE_TO_RAD(450),
+		.accel_max_val = IIO_M_S_2_TO_G(22500 << 16),
 		.accel_max_scale = 18,
 		.temp_scale = 5650, /* 5.65 milli degree Celsius */
 		.int_clk = 2460000,
@@ -837,9 +842,9 @@ static const struct adis16480_chip_info adis16480_chip_info[] = {
 	[ADIS16495_1] = {
 		.channels = adis16485_channels,
 		.num_channels = ARRAY_SIZE(adis16485_channels),
-		.gyro_max_val = IIO_RAD_TO_DEGREE(20000),
-		.gyro_max_scale = 125,
-		.accel_max_val = IIO_M_S_2_TO_G(32000),
+		.gyro_max_val = 20000 << 16,
+		.gyro_max_scale = IIO_DEGREE_TO_RAD(125),
+		.accel_max_val = IIO_M_S_2_TO_G(32000 << 16),
 		.accel_max_scale = 8,
 		.temp_scale = 12500, /* 12.5 milli degree Celsius */
 		.int_clk = 4250000,
@@ -850,9 +855,9 @@ static const struct adis16480_chip_info adis16480_chip_info[] = {
 	[ADIS16495_2] = {
 		.channels = adis16485_channels,
 		.num_channels = ARRAY_SIZE(adis16485_channels),
-		.gyro_max_val = IIO_RAD_TO_DEGREE(18000),
-		.gyro_max_scale = 450,
-		.accel_max_val = IIO_M_S_2_TO_G(32000),
+		.gyro_max_val = 18000 << 16,
+		.gyro_max_scale = IIO_DEGREE_TO_RAD(450),
+		.accel_max_val = IIO_M_S_2_TO_G(32000 << 16),
 		.accel_max_scale = 8,
 		.temp_scale = 12500, /* 12.5 milli degree Celsius */
 		.int_clk = 4250000,
@@ -863,9 +868,9 @@ static const struct adis16480_chip_info adis16480_chip_info[] = {
 	[ADIS16495_3] = {
 		.channels = adis16485_channels,
 		.num_channels = ARRAY_SIZE(adis16485_channels),
-		.gyro_max_val = IIO_RAD_TO_DEGREE(20000),
-		.gyro_max_scale = 2000,
-		.accel_max_val = IIO_M_S_2_TO_G(32000),
+		.gyro_max_val = 20000 << 16,
+		.gyro_max_scale = IIO_DEGREE_TO_RAD(2000),
+		.accel_max_val = IIO_M_S_2_TO_G(32000 << 16),
 		.accel_max_scale = 8,
 		.temp_scale = 12500, /* 12.5 milli degree Celsius */
 		.int_clk = 4250000,
@@ -876,9 +881,9 @@ static const struct adis16480_chip_info adis16480_chip_info[] = {
 	[ADIS16497_1] = {
 		.channels = adis16485_channels,
 		.num_channels = ARRAY_SIZE(adis16485_channels),
-		.gyro_max_val = IIO_RAD_TO_DEGREE(20000),
-		.gyro_max_scale = 125,
-		.accel_max_val = IIO_M_S_2_TO_G(32000),
+		.gyro_max_val = 20000 << 16,
+		.gyro_max_scale = IIO_DEGREE_TO_RAD(125),
+		.accel_max_val = IIO_M_S_2_TO_G(32000 << 16),
 		.accel_max_scale = 40,
 		.temp_scale = 12500, /* 12.5 milli degree Celsius */
 		.int_clk = 4250000,
@@ -889,9 +894,9 @@ static const struct adis16480_chip_info adis16480_chip_info[] = {
 	[ADIS16497_2] = {
 		.channels = adis16485_channels,
 		.num_channels = ARRAY_SIZE(adis16485_channels),
-		.gyro_max_val = IIO_RAD_TO_DEGREE(18000),
-		.gyro_max_scale = 450,
-		.accel_max_val = IIO_M_S_2_TO_G(32000),
+		.gyro_max_val = 18000 << 16,
+		.gyro_max_scale = IIO_DEGREE_TO_RAD(450),
+		.accel_max_val = IIO_M_S_2_TO_G(32000 << 16),
 		.accel_max_scale = 40,
 		.temp_scale = 12500, /* 12.5 milli degree Celsius */
 		.int_clk = 4250000,
@@ -902,9 +907,9 @@ static const struct adis16480_chip_info adis16480_chip_info[] = {
 	[ADIS16497_3] = {
 		.channels = adis16485_channels,
 		.num_channels = ARRAY_SIZE(adis16485_channels),
-		.gyro_max_val = IIO_RAD_TO_DEGREE(20000),
-		.gyro_max_scale = 2000,
-		.accel_max_val = IIO_M_S_2_TO_G(32000),
+		.gyro_max_val = 20000 << 16,
+		.gyro_max_scale = IIO_DEGREE_TO_RAD(2000),
+		.accel_max_val = IIO_M_S_2_TO_G(32000 << 16),
 		.accel_max_scale = 40,
 		.temp_scale = 12500, /* 12.5 milli degree Celsius */
 		.int_clk = 4250000,