1 files changed, 29 insertions, 16 deletions

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));