Patch "iio: adc: ti-ads1015: fix incorrect data rate setting update" has been added to the 4.12-stable tree

Patch "iio: adc: ti-ads1015: fix incorrect data rate setting update" has been added to the 4.12-stable tree

[gregkh]

This is a note to let you know that I've just added the patch titled

    iio: adc: ti-ads1015: fix incorrect data rate setting update

to the 4.12-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     iio-adc-ti-ads1015-fix-incorrect-data-rate-setting-update.patch
and it can be found in the queue-4.12 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@vger.kernel.org> know about it.


>From 0d106b74c558e3000aa0e058b4725cacb70ce77a Mon Sep 17 00:00:00 2001
From: Akinobu Mita <akinobu.mita@gmail.com>
Date: Fri, 21 Jul 2017 00:24:17 +0900
Subject: iio: adc: ti-ads1015: fix incorrect data rate setting update

From: Akinobu Mita <akinobu.mita@gmail.com>

commit 0d106b74c558e3000aa0e058b4725cacb70ce77a upstream.

The ti-ads1015 driver has eight iio voltage channels and each iio channel
can hold own sampling frequency information.

The ADS1015 device only have a single config register which contains an
input multiplexer selection, PGA and data rate settings.  So the driver
should load the correct settings when the input multiplexer selection is
changed.

However, regardless of which channlel is currently selected, changing any
iio channel's sampling frequency information immediately overwrites the
current data rate setting in the config register.

It breaks the current data rate setting if the different channel's sampling
frequency information is changed because the data rate setting is not
reloaded when the input multiplexer is switched.

This removes the unexpected config register update and correctly load the
data rate setting before getting adc result.

Cc: Daniel Baluta <daniel.baluta@gmail.com>
Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 drivers/iio/adc/ti-ads1015.c |   27 ++++++++++-----------------
 1 file changed, 10 insertions(+), 17 deletions(-)

--- a/drivers/iio/adc/ti-ads1015.c
+++ b/drivers/iio/adc/ti-ads1015.c
@@ -252,9 +252,11 @@ int ads1015_get_adc_result(struct ads101
 
 	ret = regmap_update_bits_check(data->regmap, ADS1015_CFG_REG,
 				       ADS1015_CFG_MUX_MASK |
-				       ADS1015_CFG_PGA_MASK,
+				       ADS1015_CFG_PGA_MASK |
+				       ADS1015_CFG_DR_MASK,
 				       chan << ADS1015_CFG_MUX_SHIFT |
-				       pga << ADS1015_CFG_PGA_SHIFT,
+				       pga << ADS1015_CFG_PGA_SHIFT |
+				       dr << ADS1015_CFG_DR_SHIFT,
 				       &change);
 	if (ret < 0)
 		return ret;
@@ -325,25 +327,16 @@ static int ads1015_set_scale(struct ads1
 
 static int ads1015_set_data_rate(struct ads1015_data *data, int chan, int rate)
 {
-	int i, ret, rindex = -1;
+	int i;
 
-	for (i = 0; i < ARRAY_SIZE(ads1015_data_rate); i++)
+	for (i = 0; i < ARRAY_SIZE(ads1015_data_rate); i++) {
 		if (data->data_rate[i] == rate) {
-			rindex = i;
-			break;
+			data->channel_data[chan].data_rate = i;
+			return 0;
 		}
-	if (rindex < 0)
-		return -EINVAL;
-
-	ret = regmap_update_bits(data->regmap, ADS1015_CFG_REG,
-				 ADS1015_CFG_DR_MASK,
-				 rindex << ADS1015_CFG_DR_SHIFT);
-	if (ret < 0)
-		return ret;
-
-	data->channel_data[chan].data_rate = rindex;
+	}
 
-	return 0;
+	return -EINVAL;
 }
 
 static int ads1015_read_raw(struct iio_dev *indio_dev,


Patches currently in stable-queue which might be from akinobu.mita@gmail.com are

queue-4.12/iio-adc-ti-ads1015-enable-conversion-when-config_pm-is-not-set.patch
queue-4.12/iio-adc-ti-ads1015-add-adequate-wait-time-to-get-correct-conversion.patch
queue-4.12/iio-adc-ti-ads1015-don-t-return-invalid-value-from-buffer-setup-callbacks.patch
queue-4.12/iio-adc-ti-ads1015-fix-incorrect-data-rate-setting-update.patch
queue-4.12/iio-adc-ti-ads1015-fix-scale-information-for-ads1115.patch
queue-4.12/iio-adc-ti-ads1015-avoid-getting-stale-result-after-runtime-resume.patch