Merge tag 'iio-fixes-for-5.6a' of git://git.kernel.org/pub/scm/linux/kernel/git/jic23/iio into staging-linus

Jonathan writes:

First set of IIO fixes in the 5.6 cycle.

* adxl372
  - Fix marking of buffered values as big endian.
* ak8974
  - Fix wrong handling of negative values when read from sysfs.
* at91-sama5d2
  - Fix differential mode by ensuring configuration set correctly.
* ping
  - Use the write sensor type for of_ping_match table.
* sps30
  - Kconfig build dependency fix.
* st-sensors
  - Fix a wrong identification of which part the SMO8840 ACPI ID indicates.
* stm32-dsfdm
  - Fix a sleep in atomic issue by not using a trigger when it makes no sense.
* stm32-timer
  - Make sure master mode is disabled when stopping.
* vcnl400
  - Update some sampling periods based on new docs.

* tag 'iio-fixes-for-5.6a' of git://git.kernel.org/pub/scm/linux/kernel/git/jic23/iio:
  iio: ping: set pa_laser_ping_cfg in of_ping_match
  iio: chemical: sps30: fix missing triggered buffer dependency
  iio: st_sensors: remap SMO8840 to LIS2DH12
  iio: light: vcnl4000: update sampling periods for vcnl4040
  iio: light: vcnl4000: update sampling periods for vcnl4200
  iio: accel: adxl372: Set iio_chan BE
  iio: magnetometer: ak8974: Fix negative raw values in sysfs
  iio: trigger: stm32-timer: disable master mode when stopping
  iio: adc: stm32-dfsdm: fix sleep in atomic context
  iio: adc: at91-sama5d2_adc: fix differential channels in triggered mode

2 files changed, 25 insertions, 33 deletions

diff --git a/drivers/iio/adc/at91-sama5d2_adc.c b/drivers/iio/adc/at91-sama5d2_adc.c
index a5c7771227d5..9d96f7d08b95 100644
--- a/drivers/iio/adc/at91-sama5d2_adc.c
+++ b/drivers/iio/adc/at91-sama5d2_adc.c
@@ -723,6 +723,7 @@ static int at91_adc_configure_trigger(struct iio_trigger *trig, bool state)
 
 	for_each_set_bit(bit, indio->active_scan_mask, indio->num_channels) {
 		struct iio_chan_spec const *chan = at91_adc_chan_get(indio, bit);
+		u32 cor;
 
 		if (!chan)
 			continue;
@@ -732,6 +733,20 @@ static int at91_adc_configure_trigger(struct iio_trigger *trig, bool state)
 			continue;
 
 		if (state) {
+			cor = at91_adc_readl(st, AT91_SAMA5D2_COR);
+
+			if (chan->differential)
+				cor |= (BIT(chan->channel) |
+					BIT(chan->channel2)) <<
+					AT91_SAMA5D2_COR_DIFF_OFFSET;
+			else
+				cor &= ~(BIT(chan->channel) <<
+				       AT91_SAMA5D2_COR_DIFF_OFFSET);
+
+			at91_adc_writel(st, AT91_SAMA5D2_COR, cor);
+		}
+
+		if (state) {
 			at91_adc_writel(st, AT91_SAMA5D2_CHER,
 					BIT(chan->channel));
 			/* enable irq only if not using DMA */
diff --git a/drivers/iio/adc/stm32-dfsdm-adc.c b/drivers/iio/adc/stm32-dfsdm-adc.c
index 2aad2cda6943..76a60d93fe23 100644
--- a/drivers/iio/adc/stm32-dfsdm-adc.c
+++ b/drivers/iio/adc/stm32-dfsdm-adc.c
@@ -842,31 +842,6 @@ static inline void stm32_dfsdm_process_data(struct stm32_dfsdm_adc *adc,
 	}
 }
 
-static irqreturn_t stm32_dfsdm_adc_trigger_handler(int irq, void *p)
-{
-	struct iio_poll_func *pf = p;
-	struct iio_dev *indio_dev = pf->indio_dev;
-	struct stm32_dfsdm_adc *adc = iio_priv(indio_dev);
-	int available = stm32_dfsdm_adc_dma_residue(adc);
-
-	while (available >= indio_dev->scan_bytes) {
-		s32 *buffer = (s32 *)&adc->rx_buf[adc->bufi];
-
-		stm32_dfsdm_process_data(adc, buffer);
-
-		iio_push_to_buffers_with_timestamp(indio_dev, buffer,
-						   pf->timestamp);
-		available -= indio_dev->scan_bytes;
-		adc->bufi += indio_dev->scan_bytes;
-		if (adc->bufi >= adc->buf_sz)
-			adc->bufi = 0;
-	}
-
-	iio_trigger_notify_done(indio_dev->trig);
-
-	return IRQ_HANDLED;
-}
-
 static void stm32_dfsdm_dma_buffer_done(void *data)
 {
 	struct iio_dev *indio_dev = data;
@@ -874,11 +849,6 @@ static void stm32_dfsdm_dma_buffer_done(void *data)
 	int available = stm32_dfsdm_adc_dma_residue(adc);
 	size_t old_pos;
 
-	if (indio_dev->currentmode & INDIO_BUFFER_TRIGGERED) {
-		iio_trigger_poll_chained(indio_dev->trig);
-		return;
-	}
-
 	/*
 	 * FIXME: In Kernel interface does not support cyclic DMA buffer,and
 	 * offers only an interface to push data samples per samples.
@@ -906,7 +876,15 @@ static void stm32_dfsdm_dma_buffer_done(void *data)
 			adc->bufi = 0;
 			old_pos = 0;
 		}
-		/* regular iio buffer without trigger */
+		/*
+		 * In DMA mode the trigger services of IIO are not used
+		 * (e.g. no call to iio_trigger_poll).
+		 * Calling irq handler associated to the hardware trigger is not
+		 * relevant as the conversions have already been done. Data
+		 * transfers are performed directly in DMA callback instead.
+		 * This implementation avoids to call trigger irq handler that
+		 * may sleep, in an atomic context (DMA irq handler context).
+		 */
 		if (adc->dev_data->type == DFSDM_IIO)
 			iio_push_to_buffers(indio_dev, buffer);
 	}
@@ -1536,8 +1514,7 @@ static int stm32_dfsdm_adc_init(struct iio_dev *indio_dev)
 	}
 
 	ret = iio_triggered_buffer_setup(indio_dev,
-					 &iio_pollfunc_store_time,
-					 &stm32_dfsdm_adc_trigger_handler,
+					 &iio_pollfunc_store_time, NULL,
 					 &stm32_dfsdm_buffer_setup_ops);
 	if (ret) {
 		stm32_dfsdm_dma_release(indio_dev);