diff --git a/drivers/iio/adc/at91-sama5d2_adc.c b/drivers/iio/adc/at91-sama5d2_adc.c
index bc5b38e3a147..a70ef7fec95f 100644
--- a/drivers/iio/adc/at91-sama5d2_adc.c
+++ b/drivers/iio/adc/at91-sama5d2_adc.c
@@ -225,6 +225,7 @@ struct at91_adc_trigger {
 	char				*name;
 	unsigned int			trgmod_value;
 	unsigned int			edge_type;
+	bool				hw_trig;
 };
 
 struct at91_adc_state {
@@ -254,16 +255,25 @@ static const struct at91_adc_trigger at91_adc_trigger_list[] = {
 		.name = "external_rising",
 		.trgmod_value = AT91_SAMA5D2_TRGR_TRGMOD_EXT_TRIG_RISE,
 		.edge_type = IRQ_TYPE_EDGE_RISING,
+		.hw_trig = true,
 	},
 	{
 		.name = "external_falling",
 		.trgmod_value = AT91_SAMA5D2_TRGR_TRGMOD_EXT_TRIG_FALL,
 		.edge_type = IRQ_TYPE_EDGE_FALLING,
+		.hw_trig = true,
 	},
 	{
 		.name = "external_any",
 		.trgmod_value = AT91_SAMA5D2_TRGR_TRGMOD_EXT_TRIG_ANY,
 		.edge_type = IRQ_TYPE_EDGE_BOTH,
+		.hw_trig = true,
+	},
+	{
+		.name = "software",
+		.trgmod_value = AT91_SAMA5D2_TRGR_TRGMOD_NO_TRIGGER,
+		.edge_type = IRQ_TYPE_NONE,
+		.hw_trig = false,
 	},
 };
 
@@ -597,7 +607,7 @@ static int at91_adc_probe(struct platform_device *pdev)
 	struct at91_adc_state *st;
 	struct resource	*res;
 	int ret, i;
-	u32 edge_type;
+	u32 edge_type = IRQ_TYPE_NONE;
 
 	indio_dev = devm_iio_device_alloc(&pdev->dev, sizeof(*st));
 	if (!indio_dev)
@@ -641,14 +651,14 @@ static int at91_adc_probe(struct platform_device *pdev)
 	ret = of_property_read_u32(pdev->dev.of_node,
 				   "atmel,trigger-edge-type", &edge_type);
 	if (ret) {
-		dev_err(&pdev->dev,
-			"invalid or missing value for atmel,trigger-edge-type\n");
-		return ret;
+		dev_dbg(&pdev->dev,
+			"atmel,trigger-edge-type not specified, only software trigger available\n");
 	}
 
 	st->selected_trig = NULL;
 
-	for (i = 0; i < AT91_SAMA5D2_HW_TRIG_CNT; i++)
+	/* find the right trigger, or no trigger at all */
+	for (i = 0; i < AT91_SAMA5D2_HW_TRIG_CNT + 1; i++)
 		if (at91_adc_trigger_list[i].edge_type == edge_type) {
 			st->selected_trig = &at91_adc_trigger_list[i];
 			break;
@@ -717,24 +727,27 @@ static int at91_adc_probe(struct platform_device *pdev)
 
 	platform_set_drvdata(pdev, indio_dev);
 
-	ret = at91_adc_buffer_init(indio_dev);
-	if (ret < 0) {
-		dev_err(&pdev->dev, "couldn't initialize the buffer.\n");
-		goto per_clk_disable_unprepare;
-	}
+	if (st->selected_trig->hw_trig) {
+		ret = at91_adc_buffer_init(indio_dev);
+		if (ret < 0) {
+			dev_err(&pdev->dev, "couldn't initialize the buffer.\n");
+			goto per_clk_disable_unprepare;
+		}
 
-	ret = at91_adc_trigger_init(indio_dev);
-	if (ret < 0) {
-		dev_err(&pdev->dev, "couldn't setup the triggers.\n");
-		goto per_clk_disable_unprepare;
+		ret = at91_adc_trigger_init(indio_dev);
+		if (ret < 0) {
+			dev_err(&pdev->dev, "couldn't setup the triggers.\n");
+			goto per_clk_disable_unprepare;
+		}
 	}
 
 	ret = iio_device_register(indio_dev);
 	if (ret < 0)
 		goto per_clk_disable_unprepare;
 
-	dev_info(&pdev->dev, "setting up trigger as %s\n",
-		 st->selected_trig->name);
+	if (st->selected_trig->hw_trig)
+		dev_info(&pdev->dev, "setting up trigger as %s\n",
+			 st->selected_trig->name);
 
 	dev_info(&pdev->dev, "version: %x\n",
 		 readl_relaxed(st->base + AT91_SAMA5D2_VERSION));