iio: adc: ad_sigma_delta: introduct devm_ad_sd_setup_buffer_and_trigger()

This is a version of ad_sd_setup_buffer_and_trigger() with all underlying
functions (that are used) being replaced with their device-managed
variants.

One thing to take care here is with {devm_}iio_trigger_alloc(), where both
functions take a parent-device object as the first parameter.

To make sure nothing quirky is happening, the devm_ad_sd_probe_trigger()
function is checking that the provided 'dev' reference is the same as the
one stored on the 'struct ad_sigma_delta' driver data.
Signed-off-by: Alexandru Ardelean <aardelean@deviqon.com>
Link: https://lore.kernel.org/r/20210513120752.90074-6-aardelean@deviqon.comSigned-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

drivers/iio/adc/ad_sigma_delta.c

@@ -513,6 +513,46 @@ static int ad_sd_probe_trigger(struct iio_dev *indio_dev)
 	return ret;
 }
 
+static int devm_ad_sd_probe_trigger(struct device *dev, struct iio_dev *indio_dev)
+{
+	struct ad_sigma_delta *sigma_delta = iio_device_get_drvdata(indio_dev);
+	int ret;
+
+	if (dev != &sigma_delta->spi->dev) {
+		dev_err(dev, "Trigger parent should be '%s', got '%s'\n",
+			dev_name(dev), dev_name(&sigma_delta->spi->dev));
+		return -EFAULT;
+	}
+
+	sigma_delta->trig = devm_iio_trigger_alloc(dev, "%s-dev%d", indio_dev->name,
+						   iio_device_id(indio_dev));
+	if (sigma_delta->trig == NULL)
+		return -ENOMEM;
+
+	sigma_delta->trig->ops = &ad_sd_trigger_ops;
+	init_completion(&sigma_delta->completion);
+
+	sigma_delta->irq_dis = true;
+	ret = devm_request_irq(dev, sigma_delta->spi->irq,
+			       ad_sd_data_rdy_trig_poll,
+			       sigma_delta->info->irq_flags | IRQF_NO_AUTOEN,
+			       indio_dev->name,
+			       sigma_delta);
+	if (ret)
+		return ret;
+
+	iio_trigger_set_drvdata(sigma_delta->trig, sigma_delta);
+
+	ret = devm_iio_trigger_register(dev, sigma_delta->trig);
+	if (ret)
+		return ret;
+
+	/* select default trigger */
+	indio_dev->trig = iio_trigger_get(sigma_delta->trig);
+
+	return 0;
+}
+
 static void ad_sd_remove_trigger(struct iio_dev *indio_dev)
 {
 	struct ad_sigma_delta *sigma_delta = iio_device_get_drvdata(indio_dev);
@@ -556,6 +596,26 @@ void ad_sd_cleanup_buffer_and_trigger(struct iio_dev *indio_dev)
 }
 EXPORT_SYMBOL_GPL(ad_sd_cleanup_buffer_and_trigger);
 
+/**
+ * devm_ad_sd_setup_buffer_and_trigger() - Device-managed buffer & trigger setup
+ * @dev: Device object to which to bind the life-time of the resources attached
+ * @indio_dev: The IIO device
+ */
+int devm_ad_sd_setup_buffer_and_trigger(struct device *dev, struct iio_dev *indio_dev)
+{
+	int ret;
+
+	ret = devm_iio_triggered_buffer_setup(dev, indio_dev,
+					      &iio_pollfunc_store_time,
+					      &ad_sd_trigger_handler,
+					      &ad_sd_buffer_setup_ops);
+	if (ret)
+		return ret;
+
+	return devm_ad_sd_probe_trigger(dev, indio_dev);
+}
+EXPORT_SYMBOL_GPL(devm_ad_sd_setup_buffer_and_trigger);
+
 /**
  * ad_sd_init() - Initializes a ad_sigma_delta struct
  * @sigma_delta: The ad_sigma_delta device

include/linux/iio/adc/ad_sigma_delta.h

@@ -26,6 +26,7 @@ struct ad_sd_calib_data {
 };
 
 struct ad_sigma_delta;
+struct device;
 struct iio_dev;
 
 /**
@@ -135,6 +136,8 @@ int ad_sd_init(struct ad_sigma_delta *sigma_delta, struct iio_dev *indio_dev,
 int ad_sd_setup_buffer_and_trigger(struct iio_dev *indio_dev);
 void ad_sd_cleanup_buffer_and_trigger(struct iio_dev *indio_dev);
 
+int devm_ad_sd_setup_buffer_and_trigger(struct device *dev, struct iio_dev *indio_dev);
+
 int ad_sd_validate_trigger(struct iio_dev *indio_dev, struct iio_trigger *trig);
 
 #endif