From 5999ec53f60b270adf0a59edb63043fe60bc3464 Mon Sep 17 00:00:00 2001
From: Peter Meerwald <pmeerw@pmeerw.net>
Date: Tue, 20 May 2014 08:36:00 +0100
Subject: [PATCH] iio: Fix two mpl3115 issues in measurement conversion
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commit d29f592929489d0a7c414396fae28119f3d280e1 upstream.
(i) pressure is 20-bit unsigned, not signed; the buffer description
is incorrect; for raw reads, this is just cosmetic
(ii) temperature is 12-bit signed, not 16-bit; this affects
readout of temperatures below zero as the sign bit is incorrectly
processed
reported via private mail
Signed-off-by: Peter Meerwald <pmeerw@pmeerw.net>
Reported-by: Robert Deliën <robert@delien.nl>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
drivers/iio/pressure/mpl3115.c | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)
diff --git a/drivers/iio/pressure/mpl3115.c b/drivers/iio/pressure/mpl3115.c
index ba6d0c5..01b2e0b 100644
--- a/drivers/iio/pressure/mpl3115.c
+++ b/drivers/iio/pressure/mpl3115.c
@@ -98,7 +98,7 @@ static int mpl3115_read_raw(struct iio_dev *indio_dev,
mutex_unlock(&data->lock);
if (ret < 0)
return ret;
- *val = sign_extend32(be32_to_cpu(tmp) >> 12, 23);
+ *val = be32_to_cpu(tmp) >> 12;
return IIO_VAL_INT;
case IIO_TEMP: /* in 0.0625 celsius / LSB */
mutex_lock(&data->lock);
@@ -112,7 +112,7 @@ static int mpl3115_read_raw(struct iio_dev *indio_dev,
mutex_unlock(&data->lock);
if (ret < 0)
return ret;
- *val = sign_extend32(be32_to_cpu(tmp) >> 20, 15);
+ *val = sign_extend32(be32_to_cpu(tmp) >> 20, 11);
return IIO_VAL_INT;
default:
return -EINVAL;
@@ -185,7 +185,7 @@ static const struct iio_chan_spec mpl3115_channels[] = {
BIT(IIO_CHAN_INFO_SCALE),
.scan_index = 0,
.scan_type = {
- .sign = 's',
+ .sign = 'u',
.realbits = 20,
.storagebits = 32,
.shift = 12,
--
1.9.1