iio: fix drivers that check buffer->scan_mask

commit 70dddeee upstream.

If the in-kernel push interface is used we may have a different masks
on the device buffer and the kernel buffer and in this case the device
should generate data for the reunion of the buffers, which is
available at indio_dev->active_scan_mask.

Compiled tested only except for bmc150-accel which was tested at
runtime with the hardware.
Signed-off-by: Octavian Purdila <octavian.purdila@intel.com>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>
[ luis: backported to 3.16: dropped changes to:
  - drivers/iio/accel/bmc150-accel.c
  - drivers/iio/accel/kxcjk-1013.c
  - drivers/iio/gyro/bmg160.c
  - drivers/iio/imu/kmx61.c
  - drivers/iio/proximity/sx9500.c ]
Signed-off-by: Luis Henriques <luis.henriques@canonical.com>

drivers/iio/accel/bma180.c

@@ -483,7 +483,7 @@ static irqreturn_t bma180_trigger_handler(int irq, void *p)
 
 	mutex_lock(&data->mutex);
 
-	for_each_set_bit(bit, indio_dev->buffer->scan_mask,
+	for_each_set_bit(bit, indio_dev->active_scan_mask,
 			 indio_dev->masklength) {
 		ret = bma180_get_acc_reg(data, bit);
 		if (ret < 0) {

drivers/iio/adc/at91_adc.c

@@ -544,7 +544,6 @@ static int at91_adc_configure_trigger(struct iio_trigger *trig, bool state)
 {
 	struct iio_dev *idev = iio_trigger_get_drvdata(trig);
 	struct at91_adc_state *st = iio_priv(idev);
-	struct iio_buffer *buffer = idev->buffer;
 	struct at91_adc_reg_desc *reg = st->registers;
 	u32 status = at91_adc_readl(st, reg->trigger_register);
 	int value;
@@ -564,7 +563,7 @@ static int at91_adc_configure_trigger(struct iio_trigger *trig, bool state)
 		at91_adc_writel(st, reg->trigger_register,
 				status | value);
 
-		for_each_set_bit(bit, buffer->scan_mask,
+		for_each_set_bit(bit, idev->active_scan_mask,
 				 st->num_channels) {
 			struct iio_chan_spec const *chan = idev->channels + bit;
 			at91_adc_writel(st, AT91_ADC_CHER,
@@ -579,7 +578,7 @@ static int at91_adc_configure_trigger(struct iio_trigger *trig, bool state)
 		at91_adc_writel(st, reg->trigger_register,
 				status & ~value);
 
-		for_each_set_bit(bit, buffer->scan_mask,
+		for_each_set_bit(bit, idev->active_scan_mask,
 				 st->num_channels) {
 			struct iio_chan_spec const *chan = idev->channels + bit;
 			at91_adc_writel(st, AT91_ADC_CHDR,

drivers/iio/adc/ti_am335x_adc.c

@@ -189,12 +189,11 @@ static int tiadc_buffer_preenable(struct iio_dev *indio_dev)
 static int tiadc_buffer_postenable(struct iio_dev *indio_dev)
 {
 	struct tiadc_device *adc_dev = iio_priv(indio_dev);
-	struct iio_buffer *buffer = indio_dev->buffer;
 	unsigned int enb = 0;
 	u8 bit;
 
 	tiadc_step_config(indio_dev);
-	for_each_set_bit(bit, buffer->scan_mask, adc_dev->channels)
+	for_each_set_bit(bit, indio_dev->active_scan_mask, adc_dev->channels)
 		enb |= (get_adc_step_bit(adc_dev, bit) << 1);
 	adc_dev->buffer_en_ch_steps = enb;