7 Commits

Author SHA1 Message Date
Linus Walleij
148bab179f iio: afe: rescale: Fix boolean logic bug
commit 9decacd8b3a432316d61c4366f302e63384cb08d upstream.

When introducing support for processed channels I needed
to invert the expression:

  if (!iio_channel_has_info(schan, IIO_CHAN_INFO_RAW) ||
      !iio_channel_has_info(schan, IIO_CHAN_INFO_SCALE))
        dev_err(dev, "source channel does not support raw/scale\n");

To the inverse, meaning detect when we can usse raw+scale
rather than when we can not. This was the result:

  if (iio_channel_has_info(schan, IIO_CHAN_INFO_RAW) ||
      iio_channel_has_info(schan, IIO_CHAN_INFO_SCALE))
       dev_info(dev, "using raw+scale source channel\n");

Ooops. Spot the error. Yep old George Boole came up and bit me.
That should be an &&.

The current code "mostly works" because we have not run into
systems supporting only raw but not scale or only scale but not
raw, and I doubt there are few using the rescaler on anything
such, but let's fix the logic.

Cc: Liam Beguin <liambeguin@gmail.com>
Cc: stable@vger.kernel.org
Fixes: 53ebee949980 ("iio: afe: iio-rescale: Support processed channels")
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Reviewed-by: Liam Beguin <liambeguin@gmail.com>
Acked-by: Peter Rosin <peda@axentia.se>
Link: https://lore.kernel.org/r/20220524075448.140238-1-linus.walleij@linaro.org
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-06-29 09:03:28 +02:00
Liam Beguin
1cb35faea3 iio: afe: rescale: use s64 for temporary scale calculations
commit 51593106b608ae4247cc8da928813347da16d025 upstream.

All four scaling coefficients can take signed values.
Make tmp a signed 64-bit integer and switch to div_s64() to preserve
signs during 64-bit divisions.

Fixes: 8b74816b5a9a ("iio: afe: rescale: new driver")
Signed-off-by: Liam Beguin <liambeguin@gmail.com>
Reviewed-by: Peter Rosin <peda@axentia.se>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Link: https://lore.kernel.org/r/20220108205319.2046348-5-liambeguin@gmail.com
Cc: <Stable@vger.kernel.org>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-04-08 14:22:50 +02:00
Linus Walleij
53ebee9499 iio: afe: iio-rescale: Support processed channels
It happens that an ADC will only provide raw or processed
voltage conversion channels. (adc/ab8500-gpadc.c).
On the Samsung GT-I9070 this is used for a light sensor
and current sense amplifier so we need to think of something.

The idea is to allow processed channels and scale them
with 1/1 and then the rescaler can modify the result
on top.

Link: https://lore.kernel.org/linux-iio/20201101232211.1194304-1-linus.walleij@linaro.org/
Cc: Peter Rosin <peda@axentia.se>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Reviewed-by: Peter Rosin <peda@axentia.se>
Link: https://lore.kernel.org/r/20210518092741.403080-1-linus.walleij@linaro.org
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
2021-06-03 18:24:13 +01:00
Krzysztof Kozlowski
bfa96be8a4 iio: afe: iio-rescale: Simplify with dev_err_probe()
Common pattern of handling deferred probe can be simplified with
dev_err_probe().  Less code and also it prints the error value.

Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Acked-by: Peter Rosin <peda@axentia.se>
Link: https://lore.kernel.org/r/20200829064726.26268-9-krzk@kernel.org
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
2020-09-03 19:40:50 +01:00
Alexandru Ardelean
d3be83244c iio: remove explicit IIO device parent assignment
This patch applies the semantic patch:
@@
expression I, P, SP;
@@
   I = devm_iio_device_alloc(P, SP);
   ...
-  I->dev.parent = P;

It updates 302 files and does 307 deletions.
This semantic patch also removes some comments like
'/* Establish that the iio_dev is a child of the i2c device */'

But this is is only done in case where the block is left empty.

The patch does not seem to cover all cases. It looks like in some cases a
different variable is used in some cases to assign the parent, but it
points to the same reference.
In other cases, the block covered by ... may be just too big to be covered
by the semantic patch.

However, this looks pretty good as well, as it does cover a big bulk of the
drivers that should remove the parent assignment.

Signed-off-by: Alexandru Ardelean <alexandru.ardelean@analog.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
2020-06-14 11:49:59 +01:00
Thomas Gleixner
ec8f24b7fa treewide: Add SPDX license identifier - Makefile/Kconfig
Add SPDX license identifiers to all Make/Kconfig files which:

 - Have no license information of any form

These files fall under the project license, GPL v2 only. The resulting SPDX
license identifier is:

  GPL-2.0-only

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-05-21 10:50:46 +02:00
Peter Rosin
8b74816b5a iio: afe: rescale: new driver
If an ADC channel measures the midpoint of a voltage divider, the
interesting voltage is often the voltage over the full resistance.
E.g. if the full voltage is too big for the ADC to handle.
Likewise, if an ADC channel measures the voltage across a shunt
resistor, with or without amplification, the interesting value is
often the current through the resistor.

This driver solves these problems by allowing to linearly scale a channel
and/or by allowing changes to the type of the channel.

Signed-off-by: Peter Rosin <peda@axentia.se>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
2018-04-28 18:03:22 +01:00