[v3,6/9] iio: adc: mcp3911: add support for interrupts

Commit Message

Marcus Folkesson July 4, 2022, 5:21 p.m. UTC

Make it possible to read values upon interrupts.
Configure Data Ready Signal Output Pin to either HiZ or push-pull and
use it as interrupt source.

Signed-off-by: Marcus Folkesson <[e-mail]>
---
 drivers/iio/adc/mcp3911.c | 52 +++++++++++++++++++++++++++++++++++++++
 1 file changed, 52 insertions(+)

Comments

Andy Shevchenko July 4, 2022, 9:57 p.m. UTC | #1

On Mon, Jul 4, 2022 at 7:21 PM Marcus Folkesson
<[e-mail]> wrote:
>
> Make it possible to read values upon interrupts.
> Configure Data Ready Signal Output Pin to either HiZ or push-pull and
> use it as interrupt source.

...

> +               /*
> +                * The device generates interrupts as long as it is powered up.
> +                * Some platforms might not allow the option to power it down so
> +                * don't enable the interrupt to avoid extra load on the system

Missed period.

> +                */

Patch

diff --git a/drivers/iio/adc/mcp3911.c b/drivers/iio/adc/mcp3911.c
index cf4dacc7de06..9c6f456bdbdf 100644
--- a/drivers/iio/adc/mcp3911.c
+++ b/drivers/iio/adc/mcp3911.c
@@ -28,6 +28,7 @@ 
 #define MCP3911_REG_GAIN		0x09
 
 #define MCP3911_REG_STATUSCOM		0x0a
+#define MCP3911_STATUSCOM_DRHIZ         BIT(12)
 #define MCP3911_STATUSCOM_READ		GENMASK(7, 6)
 #define MCP3911_STATUSCOM_CH1_24WIDTH	BIT(4)
 #define MCP3911_STATUSCOM_CH0_24WIDTH	BIT(3)
@@ -61,6 +62,7 @@  struct mcp3911 {
 	struct regulator *vref;
 	struct clk *clki;
 	u32 dev_addr;
+	struct iio_trigger *trig;
 	struct {
 		u32 channels[MCP3911_NUM_CHANNELS];
 		s64 ts __aligned(8);
@@ -346,6 +348,23 @@  static void mcp3911_cleanup(void *_adc)
 		regulator_disable(adc->vref);
 }
 
+static int mcp3911_set_trigger_state(struct iio_trigger *trig, bool enable)
+{
+	struct mcp3911 *adc = iio_trigger_get_drvdata(trig);
+
+	if (enable)
+		enable_irq(adc->spi->irq);
+	else
+		disable_irq(adc->spi->irq);
+
+	return 0;
+}
+
+static const struct iio_trigger_ops mcp3911_trigger_ops = {
+	.validate_device = iio_trigger_validate_own_device,
+	.set_trigger_state = mcp3911_set_trigger_state,
+};
+
 static int mcp3911_probe(struct spi_device *spi)
 {
 	struct iio_dev *indio_dev;
@@ -403,6 +422,14 @@  static int mcp3911_probe(struct spi_device *spi)
 	if (ret)
 		return ret;
 
+	if (device_property_read_bool(&adc->spi->dev, "microchip,data-ready-hiz"))
+		ret = mcp3911_update(adc, MCP3911_REG_STATUSCOM, MCP3911_STATUSCOM_DRHIZ,
+				0, 2);
+	else
+		ret = mcp3911_update(adc, MCP3911_REG_STATUSCOM, MCP3911_STATUSCOM_DRHIZ,
+				MCP3911_STATUSCOM_DRHIZ, 2);
+	if (ret)
+		return ret;
 
 	indio_dev->name = spi_get_device_id(spi)->name;
 	indio_dev->modes = INDIO_DIRECT_MODE;
@@ -414,6 +441,31 @@  static int mcp3911_probe(struct spi_device *spi)
 
 	mutex_init(&adc->lock);
 
+	if (spi->irq > 0) {
+		adc->trig = devm_iio_trigger_alloc(&spi->dev, "%s-dev%d",
+				indio_dev->name,
+				iio_device_id(indio_dev));
+		if (!adc->trig)
+			return PTR_ERR(adc->trig);
+
+		adc->trig->ops = &mcp3911_trigger_ops;
+		iio_trigger_set_drvdata(adc->trig, adc);
+		ret = devm_iio_trigger_register(&spi->dev, adc->trig);
+		if (ret)
+			return ret;
+
+		/*
+		 * The device generates interrupts as long as it is powered up.
+		 * Some platforms might not allow the option to power it down so
+		 * don't enable the interrupt to avoid extra load on the system
+		 */
+		ret = devm_request_irq(&spi->dev, spi->irq,
+				&iio_trigger_generic_data_rdy_poll, IRQF_NO_AUTOEN | IRQF_ONESHOT,
+				indio_dev->name, adc->trig);
+		if (ret)
+			return ret;
+	}
+
 	ret = devm_iio_triggered_buffer_setup(&spi->dev, indio_dev,
 			NULL,
 			mcp3911_trigger_handler, NULL);