patch "iio: adc: at91: fix wrong channel number in triggered buffer mode" added to staging-testing

patch "iio: adc: at91: fix wrong channel number in triggered buffer mode" added to staging-testing

[gregkh]

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

    iio: adc: at91: fix wrong channel number in triggered buffer mode

to my staging git tree which can be found at
    git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging.git
in the staging-testing branch.

The patch will show up in the next release of the linux-next tree
(usually sometime within the next 24 hours during the week.)

The patch will be merged to the staging-next branch sometime soon,
after it passes testing, and the merge window is open.

If you have any questions about this process, please let me know.


>From aea835f2dc8a682942b859179c49ad1841a6c8b9 Mon Sep 17 00:00:00 2001
From: Eugen Hristev <eugen.hristev@microchip.com>
Date: Mon, 24 Sep 2018 10:51:44 +0300
Subject: iio: adc: at91: fix wrong channel number in triggered buffer mode

When channels are registered, the hardware channel number is not the
actual iio channel number.
This is because the driver is probed with a certain number of accessible
channels. Some pins are routed and some not, depending on the description of
the board in the DT.
Because of that, channels 0,1,2,3 can correspond to hardware channels
2,3,4,5 for example.
In the buffered triggered case, we need to do the translation accordingly.
Fixed the channel number to stop reading the wrong channel.

Fixes: 0e589d5fb ("ARM: AT91: IIO: Add AT91 ADC driver.")
Cc: Maxime Ripard <maxime.ripard@bootlin.com>
Signed-off-by: Eugen Hristev <eugen.hristev@microchip.com>
Acked-by: Ludovic Desroches <ludovic.desroches@microchip.com>
Cc: <Stable@vger.kernel.org>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
---
 drivers/iio/adc/at91_adc.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/drivers/iio/adc/at91_adc.c b/drivers/iio/adc/at91_adc.c
index e3be88e7192c..75d2f73582a3 100644
--- a/drivers/iio/adc/at91_adc.c
+++ b/drivers/iio/adc/at91_adc.c
@@ -248,12 +248,14 @@ static irqreturn_t at91_adc_trigger_handler(int irq, void *p)
 	struct iio_poll_func *pf = p;
 	struct iio_dev *idev = pf->indio_dev;
 	struct at91_adc_state *st = iio_priv(idev);
+	struct iio_chan_spec const *chan;
 	int i, j = 0;
 
 	for (i = 0; i < idev->masklength; i++) {
 		if (!test_bit(i, idev->active_scan_mask))
 			continue;
-		st->buffer[j] = at91_adc_readl(st, AT91_ADC_CHAN(st, i));
+		chan = idev->channels + i;
+		st->buffer[j] = at91_adc_readl(st, AT91_ADC_CHAN(st, chan->channel));
 		j++;
 	}
 
-- 
2.19.0