Update Linux to v5.4.148

Sourced from [1]

[1] https://cdn.kernel.org/pub/linux/kernel/v5.x/linux-5.4.148.tar.gz

Change-Id: Ib3d26c5ba9b022e2e03533005c4fed4d7c30b61b
Signed-off-by: Olivier Deprez <olivier.deprez@arm.com>
diff --git a/drivers/iio/adc/stm32-dfsdm-adc.c b/drivers/iio/adc/stm32-dfsdm-adc.c
index e493242..c2948de 100644
--- a/drivers/iio/adc/stm32-dfsdm-adc.c
+++ b/drivers/iio/adc/stm32-dfsdm-adc.c
@@ -62,7 +62,7 @@
 
 struct stm32_dfsdm_dev_data {
 	int type;
-	int (*init)(struct iio_dev *indio_dev);
+	int (*init)(struct device *dev, struct iio_dev *indio_dev);
 	unsigned int num_channels;
 	const struct regmap_config *regmap_cfg;
 };
@@ -842,31 +842,6 @@
 	}
 }
 
-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 @@
 	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 @@
 			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);
 	}
@@ -1204,6 +1182,8 @@
 
 	stm32_dfsdm_stop_conv(adc);
 
+	stm32_dfsdm_process_data(adc, res);
+
 stop_dfsdm:
 	stm32_dfsdm_stop_dfsdm(adc->dfsdm);
 
@@ -1379,13 +1359,18 @@
 	}
 }
 
-static int stm32_dfsdm_dma_request(struct iio_dev *indio_dev)
+static int stm32_dfsdm_dma_request(struct device *dev,
+				   struct iio_dev *indio_dev)
 {
 	struct stm32_dfsdm_adc *adc = iio_priv(indio_dev);
 
-	adc->dma_chan = dma_request_slave_channel(&indio_dev->dev, "rx");
-	if (!adc->dma_chan)
-		return -EINVAL;
+	adc->dma_chan = dma_request_chan(dev, "rx");
+	if (IS_ERR(adc->dma_chan)) {
+		int ret = PTR_ERR(adc->dma_chan);
+
+		adc->dma_chan = NULL;
+		return ret;
+	}
 
 	adc->rx_buf = dma_alloc_coherent(adc->dma_chan->device->dev,
 					 DFSDM_DMA_BUFFER_SIZE,
@@ -1435,7 +1420,7 @@
 					  &adc->dfsdm->ch_list[ch->channel]);
 }
 
-static int stm32_dfsdm_audio_init(struct iio_dev *indio_dev)
+static int stm32_dfsdm_audio_init(struct device *dev, struct iio_dev *indio_dev)
 {
 	struct iio_chan_spec *ch;
 	struct stm32_dfsdm_adc *adc = iio_priv(indio_dev);
@@ -1462,10 +1447,10 @@
 	indio_dev->num_channels = 1;
 	indio_dev->channels = ch;
 
-	return stm32_dfsdm_dma_request(indio_dev);
+	return stm32_dfsdm_dma_request(dev, indio_dev);
 }
 
-static int stm32_dfsdm_adc_init(struct iio_dev *indio_dev)
+static int stm32_dfsdm_adc_init(struct device *dev, struct iio_dev *indio_dev)
 {
 	struct iio_chan_spec *ch;
 	struct stm32_dfsdm_adc *adc = iio_priv(indio_dev);
@@ -1509,14 +1494,22 @@
 	init_completion(&adc->completion);
 
 	/* Optionally request DMA */
-	if (stm32_dfsdm_dma_request(indio_dev)) {
-		dev_dbg(&indio_dev->dev, "No DMA support\n");
+	ret = stm32_dfsdm_dma_request(dev, indio_dev);
+	if (ret) {
+		if (ret != -ENODEV) {
+			if (ret != -EPROBE_DEFER)
+				dev_err(dev,
+					"DMA channel request failed with %d\n",
+					ret);
+			return ret;
+		}
+
+		dev_dbg(dev, "No DMA support\n");
 		return 0;
 	}
 
 	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);
@@ -1624,7 +1617,7 @@
 		adc->dfsdm->fl_list[adc->fl_id].sync_mode = val;
 
 	adc->dev_data = dev_data;
-	ret = dev_data->init(iio);
+	ret = dev_data->init(dev, iio);
 	if (ret < 0)
 		return ret;