[3.16.y-ckt stable] Patch "iio: inv-mpu: Specify the expected format/precision for write channels" has been added to staging queue

[Luis Henriques]

This is a note to let you know that I have just added a patch titled

    iio: inv-mpu: Specify the expected format/precision for write channels

to the linux-3.16.y-queue branch of the 3.16.y-ckt extended stable tree 
which can be found at:

    http://kernel.ubuntu.com/git/ubuntu/linux.git/log/?h=linux-3.16.y-queue

This patch is scheduled to be released in version 3.16.7-ckt16.

If you, or anyone else, feels it should not be added to this tree, please 
reply to this email.

For more information about the 3.16.y-ckt tree, see
https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable

Thanks.
-Luis

------

>From a86dcecb5a3e6a37c4db2937cf73bd0ff158afeb Mon Sep 17 00:00:00 2001
From: Adriana Reus <adriana.reus at intel.com>
Date: Fri, 12 Jun 2015 18:10:23 +0300
Subject: iio: inv-mpu: Specify the expected format/precision for write
 channels

commit 6a3c45bb5a385be7049a7725a4fe93eaa76915f4 upstream.

The gyroscope needs IIO_VAL_INT_PLUS_NANO for the scale channel and
unless specified write returns MICRO by default.
This needs to be properly specified so that write operations into scale
have the expected behaviour.

Signed-off-by: Adriana Reus <adriana.reus at intel.com>
Signed-off-by: Jonathan Cameron <jic23 at kernel.org>
[ luis: backported to 3.16: adjusted context ]
Signed-off-by: Luis Henriques <luis.henriques at canonical.com>
---
 drivers/iio/imu/inv_mpu6050/inv_mpu_core.c | 18 ++++++++++++++++++
 1 file changed, 18 insertions(+)

diff --git a/drivers/iio/imu/inv_mpu6050/inv_mpu_core.c b/drivers/iio/imu/inv_mpu6050/inv_mpu_core.c
index 0c6517c94a9d..63468e3c3ac8 100644
--- a/drivers/iio/imu/inv_mpu6050/inv_mpu_core.c
+++ b/drivers/iio/imu/inv_mpu6050/inv_mpu_core.c
@@ -340,6 +340,23 @@ static int inv_mpu6050_write_fsr(struct inv_mpu6050_state *st, int fsr)
 	return 0;
 }

+static int inv_write_raw_get_fmt(struct iio_dev *indio_dev,
+				 struct iio_chan_spec const *chan, long mask)
+{
+	switch (mask) {
+	case IIO_CHAN_INFO_SCALE:
+		switch (chan->type) {
+		case IIO_ANGL_VEL:
+			return IIO_VAL_INT_PLUS_NANO;
+		default:
+			return IIO_VAL_INT_PLUS_MICRO;
+		}
+	default:
+		return IIO_VAL_INT_PLUS_MICRO;
+	}
+
+	return -EINVAL;
+}
 static int inv_mpu6050_write_accel_fs(struct inv_mpu6050_state *st, int fs)
 {
 	int result;
@@ -603,6 +620,7 @@ static const struct iio_info mpu_info = {
 	.driver_module = THIS_MODULE,
 	.read_raw = &inv_mpu6050_read_raw,
 	.write_raw = &inv_mpu6050_write_raw,
+	.write_raw_get_fmt = &inv_write_raw_get_fmt,
 	.attrs = &inv_attribute_group,
 	.validate_trigger = inv_mpu6050_validate_trigger,
 };