--- /dev/null
+From c689a923c867eac40ed3826c1d9328edea8b6bc7 Mon Sep 17 00:00:00 2001
+From: Lars-Peter Clausen <lars@metafoo.de>
+Date: Wed, 5 Aug 2015 15:38:14 +0200
+Subject: iio: Add inverse unit conversion macros
+
+From: Lars-Peter Clausen <lars@metafoo.de>
+
+commit c689a923c867eac40ed3826c1d9328edea8b6bc7 upstream.
+
+Add inverse unit conversion macro to convert from standard IIO units to
+units that might be used by some devices.
+
+Those are useful in combination with scale factors that are specified as
+IIO_VAL_FRACTIONAL. Typically the denominator for those specifications will
+contain the maximum raw value the sensor will generate and the numerator
+the value it maps to in a specific unit. Sometimes datasheets specify those
+in different units than the standard IIO units (e.g. degree/s instead of
+rad/s) and so we need to do a unit conversion.
+
+From a mathematical point of view it does not make a difference whether we
+apply the unit conversion to the numerator or the inverse unit conversion
+to the denominator since (x / y) / z = x / (y * z). But as the denominator
+is typically a larger value and we are rounding both the numerator and
+denominator to integer values using the later method gives us a better
+precision (E.g. the relative error is smaller if we round 8000.3 to 8000
+rather than rounding 8.3 to 8).
+
+This is where in inverse unit conversion macros will be used.
+
+Marked for stable as used by some upcoming fixes.
+
+Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
+Signed-off-by: Jonathan Cameron <jic23@kernel.org>
+Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+
+---
+ include/linux/iio/iio.h | 17 +++++++++++++++++
+ 1 file changed, 17 insertions(+)
+
+--- a/include/linux/iio/iio.h
++++ b/include/linux/iio/iio.h
+@@ -569,6 +569,15 @@ int iio_str_to_fixpoint(const char *str,
+ #define IIO_DEGREE_TO_RAD(deg) (((deg) * 314159ULL + 9000000ULL) / 18000000ULL)
+
+ /**
++ * IIO_RAD_TO_DEGREE() - Convert rad to degree
++ * @rad: A value in rad
++ *
++ * Returns the given value converted from rad to degree
++ */
++#define IIO_RAD_TO_DEGREE(rad) \
++ (((rad) * 18000000ULL + 314159ULL / 2) / 314159ULL)
++
++/**
+ * IIO_G_TO_M_S_2() - Convert g to meter / second**2
+ * @g: A value in g
+ *
+@@ -576,4 +585,12 @@ int iio_str_to_fixpoint(const char *str,
+ */
+ #define IIO_G_TO_M_S_2(g) ((g) * 980665ULL / 100000ULL)
+
++/**
++ * IIO_M_S_2_TO_G() - Convert meter / second**2 to g
++ * @ms2: A value in meter / second**2
++ *
++ * Returns the given value converted from meter / second**2 to g
++ */
++#define IIO_M_S_2_TO_G(ms2) (((ms2) * 100000ULL + 980665ULL / 2) / 980665ULL)
++
+ #endif /* _INDUSTRIAL_IO_H_ */
--- /dev/null
+From 7abad1063deb0f77d275c61f58863ec319c58c5c Mon Sep 17 00:00:00 2001
+From: Lars-Peter Clausen <lars@metafoo.de>
+Date: Wed, 5 Aug 2015 15:38:15 +0200
+Subject: iio: adis16480: Fix scale factors
+
+From: Lars-Peter Clausen <lars@metafoo.de>
+
+commit 7abad1063deb0f77d275c61f58863ec319c58c5c upstream.
+
+The different devices support by the adis16480 driver have slightly
+different scales for the gyroscope and accelerometer channels.
+
+Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
+Signed-off-by: Jonathan Cameron <jic23@kernel.org>
+Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+
+---
+ drivers/iio/imu/adis16480.c | 39 +++++++++++++++++++++++++++++++++------
+ 1 file changed, 33 insertions(+), 6 deletions(-)
+
+--- a/drivers/iio/imu/adis16480.c
++++ b/drivers/iio/imu/adis16480.c
+@@ -110,6 +110,10 @@
+ struct adis16480_chip_info {
+ unsigned int num_channels;
+ const struct iio_chan_spec *channels;
++ unsigned int gyro_max_val;
++ unsigned int gyro_max_scale;
++ unsigned int accel_max_val;
++ unsigned int accel_max_scale;
+ };
+
+ struct adis16480 {
+@@ -533,19 +537,21 @@ static int adis16480_set_filter_freq(str
+ static int adis16480_read_raw(struct iio_dev *indio_dev,
+ const struct iio_chan_spec *chan, int *val, int *val2, long info)
+ {
++ struct adis16480 *st = iio_priv(indio_dev);
++
+ switch (info) {
+ case IIO_CHAN_INFO_RAW:
+ return adis_single_conversion(indio_dev, chan, 0, val);
+ case IIO_CHAN_INFO_SCALE:
+ switch (chan->type) {
+ case IIO_ANGL_VEL:
+- *val = 0;
+- *val2 = IIO_DEGREE_TO_RAD(20000); /* 0.02 degree/sec */
+- return IIO_VAL_INT_PLUS_MICRO;
++ *val = st->chip_info->gyro_max_scale;
++ *val2 = st->chip_info->gyro_max_val;
++ return IIO_VAL_FRACTIONAL;
+ case IIO_ACCEL:
+- *val = 0;
+- *val2 = IIO_G_TO_M_S_2(800); /* 0.8 mg */
+- return IIO_VAL_INT_PLUS_MICRO;
++ *val = st->chip_info->accel_max_scale;
++ *val2 = st->chip_info->accel_max_val;
++ return IIO_VAL_FRACTIONAL;
+ case IIO_MAGN:
+ *val = 0;
+ *val2 = 100; /* 0.0001 gauss */
+@@ -702,18 +708,39 @@ static const struct adis16480_chip_info
+ [ADIS16375] = {
+ .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.
++ */
++ .gyro_max_val = IIO_RAD_TO_DEGREE(22887),
++ .gyro_max_scale = 300,
++ .accel_max_val = IIO_M_S_2_TO_G(21973),
++ .accel_max_scale = 18,
+ },
+ [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),
++ .accel_max_scale = 5,
+ },
+ [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),
++ .accel_max_scale = 5,
+ },
+ [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),
++ .accel_max_scale = 18,
+ },
+ };
+
--- /dev/null
+From 06d2f6ca5a38abe92f1f3a132b331eee773868c3 Mon Sep 17 00:00:00 2001
+From: Markus Pargmann <mpa@pengutronix.de>
+Date: Wed, 29 Jul 2015 15:46:03 +0200
+Subject: iio: bmg160: IIO_BUFFER and IIO_TRIGGERED_BUFFER are required
+
+From: Markus Pargmann <mpa@pengutronix.de>
+
+commit 06d2f6ca5a38abe92f1f3a132b331eee773868c3 upstream.
+
+This patch adds selects for IIO_BUFFER and IIO_TRIGGERED_BUFFER. Without
+IIO_BUFFER, the driver does not compile.
+
+Signed-off-by: Markus Pargmann <mpa@pengutronix.de>
+Reviewed-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
+Signed-off-by: Jonathan Cameron <jic23@kernel.org>
+Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+
+---
+ drivers/iio/gyro/Kconfig | 3 ++-
+ 1 file changed, 2 insertions(+), 1 deletion(-)
+
+--- a/drivers/iio/gyro/Kconfig
++++ b/drivers/iio/gyro/Kconfig
+@@ -73,7 +73,8 @@ config IIO_ST_GYRO_SPI_3AXIS
+ config ITG3200
+ tristate "InvenSense ITG3200 Digital 3-Axis Gyroscope I2C driver"
+ depends on I2C
+- select IIO_TRIGGERED_BUFFER if IIO_BUFFER
++ select IIO_BUFFER
++ select IIO_TRIGGERED_BUFFER
+ help
+ Say yes here to add support for the InvenSense ITG3200 digital
+ 3-axis gyroscope sensor.
projects / thirdparty / kernel / stable-queue.git / commitdiff
