[PATCH 2/2] iio: xilinx-xadc: Make IRQ optional - Lars-Peter Clausen

From: Lars-Peter Clausen <lars@metafoo.de>
To: Jonathan Cameron <jic23@kernel.org>
Cc: Anand Ashok Dumbre <anandash@xilinx.com>,
	Michal Simek <michal.simek@xilinx.com>,
	linux-iio@vger.kernel.org, Lars-Peter Clausen <lars@metafoo.de>
Subject: [PATCH 2/2] iio: xilinx-xadc: Make IRQ optional
Date: Sun, 25 Apr 2021 12:26:38 +0200	[thread overview]
Message-ID: <20210425102638.9511-2-lars@metafoo.de> (raw)
In-Reply-To: <20210425102638.9511-1-lars@metafoo.de>

In some setups the IRQ signal of the XADC might not be wired to the host
system. The driver currently requires that an interrupt is specified. Make
the interrupt optional so the driver can be used in such setups where the
interrupt is not connected.

Since both buffered capture as well as events depend on the interrupt being
connected both are not available when the interrupt is not connected.

Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
---
 drivers/iio/adc/xilinx-xadc-core.c | 39 +++++++++++++++++++-----------
 1 file changed, 25 insertions(+), 14 deletions(-)

diff --git a/drivers/iio/adc/xilinx-xadc-core.c b/drivers/iio/adc/xilinx-xadc-core.c
index dd1c92b2811f..ffefb01a3893 100644
--- a/drivers/iio/adc/xilinx-xadc-core.c
+++ b/drivers/iio/adc/xilinx-xadc-core.c
@@ -1182,7 +1182,7 @@ static const struct of_device_id xadc_of_match_table[] = {
 MODULE_DEVICE_TABLE(of, xadc_of_match_table);
 
 static int xadc_parse_dt(struct iio_dev *indio_dev, struct device_node *np,
-	unsigned int *conf)
+	unsigned int *conf, int irq)
 {
 	struct device *dev = indio_dev->dev.parent;
 	struct xadc *xadc = iio_priv(indio_dev);
@@ -1195,6 +1195,7 @@ static int xadc_parse_dt(struct iio_dev *indio_dev, struct device_node *np,
 	u32 ext_mux_chan;
 	u32 reg;
 	int ret;
+	int i;
 
 	*conf = 0;
 
@@ -1273,6 +1274,14 @@ static int xadc_parse_dt(struct iio_dev *indio_dev, struct device_node *np,
 	}
 	of_node_put(chan_node);
 
+	/* No IRQ => no events */
+	if (irq <= 0) {
+		for (i = 0; i < num_channels; i++) {
+			channels[i].event_spec = NULL;
+			channels[i].num_event_specs = 0;
+		}
+	}
+
 	indio_dev->num_channels = num_channels;
 	indio_dev->channels = devm_krealloc(dev, channels,
 					    sizeof(*channels) * num_channels,
@@ -1322,9 +1331,9 @@ static int xadc_probe(struct platform_device *pdev)
 	if (!id)
 		return -EINVAL;
 
-	irq = platform_get_irq(pdev, 0);
-	if (irq <= 0)
-		return -ENXIO;
+	irq = platform_get_irq_optional(pdev, 0);
+	if (irq < 0 && irq != -ENXIO)
+		return irq;
 
 	indio_dev = devm_iio_device_alloc(dev, sizeof(*xadc));
 	if (!indio_dev)
@@ -1345,11 +1354,11 @@ static int xadc_probe(struct platform_device *pdev)
 	indio_dev->modes = INDIO_DIRECT_MODE;
 	indio_dev->info = &xadc_info;
 
-	ret = xadc_parse_dt(indio_dev, dev->of_node, &conf0);
+	ret = xadc_parse_dt(indio_dev, dev->of_node, &conf0, irq);
 	if (ret)
 		return ret;
 
-	if (xadc->ops->flags & XADC_FLAGS_BUFFERED) {
+	if (irq > 0 && (xadc->ops->flags & XADC_FLAGS_BUFFERED)) {
 		ret = devm_iio_triggered_buffer_setup(dev, indio_dev,
 						      &iio_pollfunc_store_time,
 						      &xadc_trigger_handler,
@@ -1396,15 +1405,17 @@ static int xadc_probe(struct platform_device *pdev)
 		}
 	}
 
-	ret = devm_request_irq(dev, irq, xadc->ops->interrupt_handler, 0,
-			       dev_name(dev), indio_dev);
-	if (ret)
-		return ret;
+	if (irq > 0) {
+		ret = devm_request_irq(dev, irq, xadc->ops->interrupt_handler,
+				       0, dev_name(dev), indio_dev);
+		if (ret)
+			return ret;
 
-	ret = devm_add_action_or_reset(dev, xadc_cancel_delayed_work,
-				       &xadc->zynq_unmask_work);
-	if (ret)
-		return ret;
+		ret = devm_add_action_or_reset(dev, xadc_cancel_delayed_work,
+					       &xadc->zynq_unmask_work);
+		if (ret)
+			return ret;
+	}
 
 	ret = xadc->ops->setup(pdev, indio_dev, irq);
 	if (ret)
-- 
2.20.1

