iio: stm32-dfsdm-adc: remove usage of iio_priv_to_dev() helper

We may want to get rid of the iio_priv_to_dev() helper. The reason is that
we will hide some of the members of the iio_dev structure (to prevent
drivers from accessing them directly), and that will also mean hiding the
implementation of the iio_priv_to_dev() helper inside the IIO core.

Hiding the implementation of iio_priv_to_dev() implies that some fast-paths
may not be fast anymore, so a general idea is to try to get rid of the
iio_priv_to_dev() altogether.
The iio_priv() helper won't be affected by the rework, as the iio_dev
struct will keep a reference to the private information.

For this driver, not using iio_priv_to_dev(), means reworking some paths to
pass the iio device and using iio_priv() to access the private information.
Signed-off-by: Alexandru Ardelean <alexandru.ardelean@analog.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

drivers/iio/adc/stm32-dfsdm-adc.c

@@ -330,9 +330,9 @@ static int stm32_dfsdm_compute_all_osrs(struct iio_dev *indio_dev,
 	return 0;
 }
 
-static int stm32_dfsdm_start_channel(struct stm32_dfsdm_adc *adc)
+static int stm32_dfsdm_start_channel(struct iio_dev *indio_dev)
 {
-	struct iio_dev *indio_dev = iio_priv_to_dev(adc);
+	struct stm32_dfsdm_adc *adc = iio_priv(indio_dev);
 	struct regmap *regmap = adc->dfsdm->regmap;
 	const struct iio_chan_spec *chan;
 	unsigned int bit;
@@ -350,9 +350,9 @@ static int stm32_dfsdm_start_channel(struct stm32_dfsdm_adc *adc)
 	return 0;
 }
 
-static void stm32_dfsdm_stop_channel(struct stm32_dfsdm_adc *adc)
+static void stm32_dfsdm_stop_channel(struct iio_dev *indio_dev)
 {
-	struct iio_dev *indio_dev = iio_priv_to_dev(adc);
+	struct stm32_dfsdm_adc *adc = iio_priv(indio_dev);
 	struct regmap *regmap = adc->dfsdm->regmap;
 	const struct iio_chan_spec *chan;
 	unsigned int bit;
@@ -418,11 +418,11 @@ static void stm32_dfsdm_stop_filter(struct stm32_dfsdm *dfsdm,
 			   DFSDM_CR1_DFEN_MASK, DFSDM_CR1_DFEN(0));
 }
 
-static int stm32_dfsdm_filter_set_trig(struct stm32_dfsdm_adc *adc,
+static int stm32_dfsdm_filter_set_trig(struct iio_dev *indio_dev,
 				       unsigned int fl_id,
 				       struct iio_trigger *trig)
 {
-	struct iio_dev *indio_dev = iio_priv_to_dev(adc);
+	struct stm32_dfsdm_adc *adc = iio_priv(indio_dev);
 	struct regmap *regmap = adc->dfsdm->regmap;
 	u32 jextsel = 0, jexten = STM32_DFSDM_JEXTEN_DISABLED;
 	int ret;
@@ -447,11 +447,11 @@ static int stm32_dfsdm_filter_set_trig(struct stm32_dfsdm_adc *adc,
 	return 0;
 }
 
-static int stm32_dfsdm_channels_configure(struct stm32_dfsdm_adc *adc,
+static int stm32_dfsdm_channels_configure(struct iio_dev *indio_dev,
 					  unsigned int fl_id,
 					  struct iio_trigger *trig)
 {
-	struct iio_dev *indio_dev = iio_priv_to_dev(adc);
+	struct stm32_dfsdm_adc *adc = iio_priv(indio_dev);
 	struct regmap *regmap = adc->dfsdm->regmap;
 	struct stm32_dfsdm_filter *fl = &adc->dfsdm->fl_list[fl_id];
 	struct stm32_dfsdm_filter_osr *flo = &fl->flo[0];
@@ -491,11 +491,11 @@ static int stm32_dfsdm_channels_configure(struct stm32_dfsdm_adc *adc,
 	return 0;
 }
 
-static int stm32_dfsdm_filter_configure(struct stm32_dfsdm_adc *adc,
+static int stm32_dfsdm_filter_configure(struct iio_dev *indio_dev,
 					unsigned int fl_id,
 					struct iio_trigger *trig)
 {
-	struct iio_dev *indio_dev = iio_priv_to_dev(adc);
+	struct stm32_dfsdm_adc *adc = iio_priv(indio_dev);
 	struct regmap *regmap = adc->dfsdm->regmap;
 	struct stm32_dfsdm_filter *fl = &adc->dfsdm->fl_list[fl_id];
 	struct stm32_dfsdm_filter_osr *flo = &fl->flo[fl->fast];
@@ -521,7 +521,7 @@ static int stm32_dfsdm_filter_configure(struct stm32_dfsdm_adc *adc,
 	if (ret)
 		return ret;
 
-	ret = stm32_dfsdm_filter_set_trig(adc, fl_id, trig);
+	ret = stm32_dfsdm_filter_set_trig(indio_dev, fl_id, trig);
 	if (ret)
 		return ret;
 
@@ -729,21 +729,22 @@ static ssize_t dfsdm_adc_audio_set_spiclk(struct iio_dev *indio_dev,
 	return len;
 }
 
-static int stm32_dfsdm_start_conv(struct stm32_dfsdm_adc *adc,
+static int stm32_dfsdm_start_conv(struct iio_dev *indio_dev,
 				  struct iio_trigger *trig)
 {
+	struct stm32_dfsdm_adc *adc = iio_priv(indio_dev);
 	struct regmap *regmap = adc->dfsdm->regmap;
 	int ret;
 
-	ret = stm32_dfsdm_channels_configure(adc, adc->fl_id, trig);
+	ret = stm32_dfsdm_channels_configure(indio_dev, adc->fl_id, trig);
 	if (ret < 0)
 		return ret;
 
-	ret = stm32_dfsdm_start_channel(adc);
+	ret = stm32_dfsdm_start_channel(indio_dev);
 	if (ret < 0)
 		return ret;
 
-	ret = stm32_dfsdm_filter_configure(adc, adc->fl_id, trig);
+	ret = stm32_dfsdm_filter_configure(indio_dev, adc->fl_id, trig);
 	if (ret < 0)
 		goto stop_channels;
 
@@ -757,13 +758,14 @@ static int stm32_dfsdm_start_conv(struct stm32_dfsdm_adc *adc,
 	regmap_update_bits(regmap, DFSDM_CR1(adc->fl_id),
 			   DFSDM_CR1_CFG_MASK, 0);
 stop_channels:
-	stm32_dfsdm_stop_channel(adc);
+	stm32_dfsdm_stop_channel(indio_dev);
 
 	return ret;
 }
 
-static void stm32_dfsdm_stop_conv(struct stm32_dfsdm_adc *adc)
+static void stm32_dfsdm_stop_conv(struct iio_dev *indio_dev)
 {
+	struct stm32_dfsdm_adc *adc = iio_priv(indio_dev);
 	struct regmap *regmap = adc->dfsdm->regmap;
 
 	stm32_dfsdm_stop_filter(adc->dfsdm, adc->fl_id);
@@ -771,7 +773,7 @@ static void stm32_dfsdm_stop_conv(struct stm32_dfsdm_adc *adc)
 	regmap_update_bits(regmap, DFSDM_CR1(adc->fl_id),
 			   DFSDM_CR1_CFG_MASK, 0);
 
-	stm32_dfsdm_stop_channel(adc);
+	stm32_dfsdm_stop_channel(indio_dev);
 }
 
 static int stm32_dfsdm_set_watermark(struct iio_dev *indio_dev,
@@ -1017,7 +1019,7 @@ static int __stm32_dfsdm_postenable(struct iio_dev *indio_dev)
 		goto stop_dfsdm;
 	}
 
-	ret = stm32_dfsdm_start_conv(adc, indio_dev->trig);
+	ret = stm32_dfsdm_start_conv(indio_dev, indio_dev->trig);
 	if (ret) {
 		dev_err(&indio_dev->dev, "Can't start conversion\n");
 		goto err_stop_dma;
@@ -1063,7 +1065,7 @@ static void __stm32_dfsdm_predisable(struct iio_dev *indio_dev)
 {
 	struct stm32_dfsdm_adc *adc = iio_priv(indio_dev);
 
-	stm32_dfsdm_stop_conv(adc);
+	stm32_dfsdm_stop_conv(indio_dev);
 
 	stm32_dfsdm_adc_dma_stop(indio_dev);
 
@@ -1159,7 +1161,7 @@ static int stm32_dfsdm_single_conv(struct iio_dev *indio_dev,
 
 	adc->nconv = 1;
 	adc->smask = BIT(chan->scan_index);
-	ret = stm32_dfsdm_start_conv(adc, NULL);
+	ret = stm32_dfsdm_start_conv(indio_dev, NULL);
 	if (ret < 0) {
 		regmap_update_bits(adc->dfsdm->regmap, DFSDM_CR2(adc->fl_id),
 				   DFSDM_CR2_REOCIE_MASK, DFSDM_CR2_REOCIE(0));
@@ -1180,7 +1182,7 @@ static int stm32_dfsdm_single_conv(struct iio_dev *indio_dev,
 	else
 		ret = IIO_VAL_INT;
 
-	stm32_dfsdm_stop_conv(adc);
+	stm32_dfsdm_stop_conv(indio_dev);
 
 	stm32_dfsdm_process_data(adc, res);
 
@@ -1313,8 +1315,8 @@ static const struct iio_info stm32_dfsdm_info_adc = {
 
 static irqreturn_t stm32_dfsdm_irq(int irq, void *arg)
 {
-	struct stm32_dfsdm_adc *adc = arg;
-	struct iio_dev *indio_dev = iio_priv_to_dev(adc);
+	struct iio_dev *indio_dev = arg;
+	struct stm32_dfsdm_adc *adc = iio_priv(indio_dev);
 	struct regmap *regmap = adc->dfsdm->regmap;
 	unsigned int status, int_en;
 
@@ -1574,7 +1576,7 @@ static int stm32_dfsdm_adc_probe(struct platform_device *pdev)
 	iio->dev.of_node = np;
 	iio->modes = INDIO_DIRECT_MODE;
 
-	platform_set_drvdata(pdev, adc);
+	platform_set_drvdata(pdev, iio);
 
 	ret = of_property_read_u32(dev->of_node, "reg", &adc->fl_id);
 	if (ret != 0 || adc->fl_id >= adc->dfsdm->num_fls) {
@@ -1603,7 +1605,7 @@ static int stm32_dfsdm_adc_probe(struct platform_device *pdev)
 		return irq;
 
 	ret = devm_request_irq(dev, irq, stm32_dfsdm_irq,
-			       0, pdev->name, adc);
+			       0, pdev->name, iio);
 	if (ret < 0) {
 		dev_err(dev, "Failed to request IRQ\n");
 		return ret;
@@ -1650,8 +1652,8 @@ static int stm32_dfsdm_adc_probe(struct platform_device *pdev)
 
 static int stm32_dfsdm_adc_remove(struct platform_device *pdev)
 {
-	struct stm32_dfsdm_adc *adc = platform_get_drvdata(pdev);
-	struct iio_dev *indio_dev = iio_priv_to_dev(adc);
+	struct iio_dev *indio_dev = platform_get_drvdata(pdev);
+	struct stm32_dfsdm_adc *adc = iio_priv(indio_dev);
 
 	if (adc->dev_data->type == DFSDM_AUDIO)
 		of_platform_depopulate(&pdev->dev);
@@ -1663,8 +1665,7 @@ static int stm32_dfsdm_adc_remove(struct platform_device *pdev)
 
 static int __maybe_unused stm32_dfsdm_adc_suspend(struct device *dev)
 {
-	struct stm32_dfsdm_adc *adc = dev_get_drvdata(dev);
-	struct iio_dev *indio_dev = iio_priv_to_dev(adc);
+	struct iio_dev *indio_dev = dev_get_drvdata(dev);
 
 	if (iio_buffer_enabled(indio_dev))
 		__stm32_dfsdm_predisable(indio_dev);
@@ -1674,8 +1675,8 @@ static int __maybe_unused stm32_dfsdm_adc_suspend(struct device *dev)
 
 static int __maybe_unused stm32_dfsdm_adc_resume(struct device *dev)
 {
-	struct stm32_dfsdm_adc *adc = dev_get_drvdata(dev);
-	struct iio_dev *indio_dev = iio_priv_to_dev(adc);
+	struct iio_dev *indio_dev = dev_get_drvdata(dev);
+	struct stm32_dfsdm_adc *adc = iio_priv(indio_dev);
 	const struct iio_chan_spec *chan;
 	struct stm32_dfsdm_channel *ch;
 	int i, ret;