patch "iio: adc: cc10001: Fix the channel number mapping" added to staging-linus

[<gregkh@linuxfoundation.org>]

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

    iio: adc: cc10001: Fix the channel number mapping

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-linus 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 hopefully also be merged in Linus's tree for the
next -rc kernel release.

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


>From 13415a998adb1802b5bd6bd5a336331589e866a1 Mon Sep 17 00:00:00 2001
From: Naidu Tellapati <naidu.tellapati@imgtec.com>
Date: Thu, 7 May 2015 18:22:17 -0300
Subject: iio: adc: cc10001: Fix the channel number mapping

When some of the ADC channels are reserved for remote CPUs,
the scan index and the corresponding channel number doesn't
match. This leads to convesion on the incorrect channel during
triggered capture.

Fix this by using a scan index to channel mapping encoded
in the iio_chan_spec for this purpose while starting conversion
on a particular ADC channel in trigger handler.

Also, the channel_map is not really used anywhere but in probe(), so
no need to keep track of it. Remove it from device structure.

While here, add 1 to number of channels to register timestamp channel
with the IIO core.

Fixes: 1664f6a5b0c8 ("iio: adc: Cosmic Circuits 10001 ADC driver")
Signed-off-by: Naidu Tellapati <naidu.tellapati@imgtec.com>
Signed-off-by: Ezequiel Garcia <ezequiel.garcia@imgtec.com>
Cc: <Stable@vger.kernel.org>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>
---
 drivers/iio/adc/cc10001_adc.c | 24 +++++++++++++-----------
 1 file changed, 13 insertions(+), 11 deletions(-)

diff --git a/drivers/iio/adc/cc10001_adc.c b/drivers/iio/adc/cc10001_adc.c
index 51e2a83c9404..357e6c213784 100644
--- a/drivers/iio/adc/cc10001_adc.c
+++ b/drivers/iio/adc/cc10001_adc.c
@@ -62,7 +62,6 @@ struct cc10001_adc_device {
 	u16 *buf;
 
 	struct mutex lock;
-	unsigned long channel_map;
 	unsigned int start_delay_ns;
 	unsigned int eoc_delay_ns;
 };
@@ -129,6 +128,7 @@ static irqreturn_t cc10001_adc_trigger_h(int irq, void *p)
 	struct iio_dev *indio_dev;
 	unsigned int delay_ns;
 	unsigned int channel;
+	unsigned int scan_idx;
 	bool sample_invalid;
 	u16 *data;
 	int i;
@@ -150,9 +150,10 @@ static irqreturn_t cc10001_adc_trigger_h(int irq, void *p)
 
 	i = 0;
 	sample_invalid = false;
-	for_each_set_bit(channel, indio_dev->active_scan_mask,
+	for_each_set_bit(scan_idx, indio_dev->active_scan_mask,
 				  indio_dev->masklength) {
 
+		channel = indio_dev->channels[scan_idx].channel;
 		cc10001_adc_start(adc_dev, channel);
 
 		data[i] = cc10001_adc_poll_done(indio_dev, channel, delay_ns);
@@ -255,22 +256,22 @@ static const struct iio_info cc10001_adc_info = {
 	.update_scan_mode = &cc10001_update_scan_mode,
 };
 
-static int cc10001_adc_channel_init(struct iio_dev *indio_dev)
+static int cc10001_adc_channel_init(struct iio_dev *indio_dev,
+				    unsigned long channel_map)
 {
-	struct cc10001_adc_device *adc_dev = iio_priv(indio_dev);
 	struct iio_chan_spec *chan_array, *timestamp;
 	unsigned int bit, idx = 0;
 
-	indio_dev->num_channels = bitmap_weight(&adc_dev->channel_map,
-						CC10001_ADC_NUM_CHANNELS);
+	indio_dev->num_channels = bitmap_weight(&channel_map,
+						CC10001_ADC_NUM_CHANNELS) + 1;
 
-	chan_array = devm_kcalloc(&indio_dev->dev, indio_dev->num_channels + 1,
+	chan_array = devm_kcalloc(&indio_dev->dev, indio_dev->num_channels,
 				  sizeof(struct iio_chan_spec),
 				  GFP_KERNEL);
 	if (!chan_array)
 		return -ENOMEM;
 
-	for_each_set_bit(bit, &adc_dev->channel_map, CC10001_ADC_NUM_CHANNELS) {
+	for_each_set_bit(bit, &channel_map, CC10001_ADC_NUM_CHANNELS) {
 		struct iio_chan_spec *chan = &chan_array[idx];
 
 		chan->type = IIO_VOLTAGE;
@@ -305,6 +306,7 @@ static int cc10001_adc_probe(struct platform_device *pdev)
 	unsigned long adc_clk_rate;
 	struct resource *res;
 	struct iio_dev *indio_dev;
+	unsigned long channel_map;
 	int ret;
 
 	indio_dev = devm_iio_device_alloc(&pdev->dev, sizeof(*adc_dev));
@@ -313,9 +315,9 @@ static int cc10001_adc_probe(struct platform_device *pdev)
 
 	adc_dev = iio_priv(indio_dev);
 
-	adc_dev->channel_map = GENMASK(CC10001_ADC_NUM_CHANNELS - 1, 0);
+	channel_map = GENMASK(CC10001_ADC_NUM_CHANNELS - 1, 0);
 	if (!of_property_read_u32(node, "adc-reserved-channels", &ret))
-		adc_dev->channel_map &= ~ret;
+		channel_map &= ~ret;
 
 	adc_dev->reg = devm_regulator_get(&pdev->dev, "vref");
 	if (IS_ERR(adc_dev->reg))
@@ -361,7 +363,7 @@ static int cc10001_adc_probe(struct platform_device *pdev)
 	adc_dev->start_delay_ns = adc_dev->eoc_delay_ns * CC10001_WAIT_CYCLES;
 
 	/* Setup the ADC channels available on the device */
-	ret = cc10001_adc_channel_init(indio_dev);
+	ret = cc10001_adc_channel_init(indio_dev, channel_map);
 	if (ret < 0)
 		goto err_disable_clk;
 
-- 
2.4.0