diff mbox series

[v3,13/15] iio: adc: stm32-adc: convert to device properties

Message ID 20220715122903.332535-14-nuno.sa@analog.com (mailing list archive)
State Handled Elsewhere
Headers show
Series make iio inkern interface firmware agnostic | expand

Commit Message

Nuno Sa July 15, 2022, 12:29 p.m. UTC
Make the conversion to firmware agnostic device properties. As part of
the conversion the IIO inkern interface 'of_xlate()' is also converted to
'fwnode_xlate()'. The goal is to completely drop 'of_xlate' and hence OF
dependencies from IIO.

Signed-off-by: Nuno Sá <nuno.sa@analog.com>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
---
 drivers/iio/adc/stm32-adc.c | 125 ++++++++++++++++++++----------------
 1 file changed, 70 insertions(+), 55 deletions(-)

Comments

Fabrice Gasnier Aug. 5, 2022, 7:25 a.m. UTC | #1
On 7/15/22 14:29, Nuno Sá wrote:
> Make the conversion to firmware agnostic device properties. As part of
> the conversion the IIO inkern interface 'of_xlate()' is also converted to
> 'fwnode_xlate()'. The goal is to completely drop 'of_xlate' and hence OF
> dependencies from IIO.
> 
> Signed-off-by: Nuno Sá <nuno.sa@analog.com>
> Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>

Hi Nuno,

You can add my:
Reviewed-by: Fabrice Gasnier <fabrice.gasnier@foss.st.com>
Tested-by: Fabrice Gasnier <fabrice.gasnier@foss.st.com>

Best Regards,
Thanks,
Fabrice

> ---
>  drivers/iio/adc/stm32-adc.c | 125 ++++++++++++++++++++----------------
>  1 file changed, 70 insertions(+), 55 deletions(-)
> 
> diff --git a/drivers/iio/adc/stm32-adc.c b/drivers/iio/adc/stm32-adc.c
> index 3985fe972892..24248f1de1d0 100644
> --- a/drivers/iio/adc/stm32-adc.c
> +++ b/drivers/iio/adc/stm32-adc.c
> @@ -21,11 +21,11 @@
>  #include <linux/io.h>
>  #include <linux/iopoll.h>
>  #include <linux/module.h>
> +#include <linux/mod_devicetable.h>
>  #include <linux/nvmem-consumer.h>
>  #include <linux/platform_device.h>
>  #include <linux/pm_runtime.h>
> -#include <linux/of.h>
> -#include <linux/of_device.h>
> +#include <linux/property.h>
>  
>  #include "stm32-adc-core.h"
>  
> @@ -241,6 +241,7 @@ struct stm32_adc_cfg {
>   * @chan_name:		channel name array
>   * @num_diff:		number of differential channels
>   * @int_ch:		internal channel indexes array
> + * @nsmps:		number of channels with optional sample time
>   */
>  struct stm32_adc {
>  	struct stm32_adc_common	*common;
> @@ -267,6 +268,7 @@ struct stm32_adc {
>  	char			chan_name[STM32_ADC_CH_MAX][STM32_ADC_CH_SZ];
>  	u32			num_diff;
>  	int			int_ch[STM32_ADC_INT_CH_NB];
> +	int			nsmps;
>  };
>  
>  struct stm32_adc_diff_channel {
> @@ -1530,8 +1532,8 @@ static int stm32_adc_update_scan_mode(struct iio_dev *indio_dev,
>  	return ret;
>  }
>  
> -static int stm32_adc_of_xlate(struct iio_dev *indio_dev,
> -			      const struct of_phandle_args *iiospec)
> +static int stm32_adc_fwnode_xlate(struct iio_dev *indio_dev,
> +				  const struct fwnode_reference_args *iiospec)
>  {
>  	int i;
>  
> @@ -1585,7 +1587,7 @@ static const struct iio_info stm32_adc_iio_info = {
>  	.hwfifo_set_watermark = stm32_adc_set_watermark,
>  	.update_scan_mode = stm32_adc_update_scan_mode,
>  	.debugfs_reg_access = stm32_adc_debugfs_reg_access,
> -	.of_xlate = stm32_adc_of_xlate,
> +	.fwnode_xlate = stm32_adc_fwnode_xlate,
>  };
>  
>  static unsigned int stm32_adc_dma_residue(struct stm32_adc *adc)
> @@ -1782,14 +1784,14 @@ static const struct iio_chan_spec_ext_info stm32_adc_ext_info[] = {
>  	{},
>  };
>  
> -static int stm32_adc_of_get_resolution(struct iio_dev *indio_dev)
> +static int stm32_adc_fw_get_resolution(struct iio_dev *indio_dev)
>  {
> -	struct device_node *node = indio_dev->dev.of_node;
> +	struct device *dev = &indio_dev->dev;
>  	struct stm32_adc *adc = iio_priv(indio_dev);
>  	unsigned int i;
>  	u32 res;
>  
> -	if (of_property_read_u32(node, "assigned-resolution-bits", &res))
> +	if (device_property_read_u32(dev, "assigned-resolution-bits", &res))
>  		res = adc->cfg->adc_info->resolutions[0];
>  
>  	for (i = 0; i < adc->cfg->adc_info->num_res; i++)
> @@ -1873,11 +1875,11 @@ static void stm32_adc_chan_init_one(struct iio_dev *indio_dev,
>  
>  static int stm32_adc_get_legacy_chan_count(struct iio_dev *indio_dev, struct stm32_adc *adc)
>  {
> -	struct device_node *node = indio_dev->dev.of_node;
> +	struct device *dev = &indio_dev->dev;
>  	const struct stm32_adc_info *adc_info = adc->cfg->adc_info;
>  	int num_channels = 0, ret;
>  
> -	ret = of_property_count_u32_elems(node, "st,adc-channels");
> +	ret = device_property_count_u32(dev, "st,adc-channels");
>  	if (ret > adc_info->max_channels) {
>  		dev_err(&indio_dev->dev, "Bad st,adc-channels?\n");
>  		return -EINVAL;
> @@ -1885,8 +1887,12 @@ static int stm32_adc_get_legacy_chan_count(struct iio_dev *indio_dev, struct stm
>  		num_channels += ret;
>  	}
>  
> -	ret = of_property_count_elems_of_size(node, "st,adc-diff-channels",
> -					      sizeof(struct stm32_adc_diff_channel));
> +	/*
> +	 * each st,adc-diff-channels is a group of 2 u32 so we divide @ret
> +	 * to get the *real* number of channels.
> +	 */
> +	ret = device_property_count_u32(dev, "st,adc-diff-channels");
> +	ret /= (int)(sizeof(struct stm32_adc_diff_channel) / sizeof(u32));
>  	if (ret > adc_info->max_channels) {
>  		dev_err(&indio_dev->dev, "Bad st,adc-diff-channels?\n");
>  		return -EINVAL;
> @@ -1896,8 +1902,8 @@ static int stm32_adc_get_legacy_chan_count(struct iio_dev *indio_dev, struct stm
>  	}
>  
>  	/* Optional sample time is provided either for each, or all channels */
> -	ret = of_property_count_u32_elems(node, "st,min-sample-time-nsecs");
> -	if (ret > 1 && ret != num_channels) {
> +	adc->nsmps = device_property_count_u32(dev, "st,min-sample-time-nsecs");
> +	if (adc->nsmps > 1 && adc->nsmps != num_channels) {
>  		dev_err(&indio_dev->dev, "Invalid st,min-sample-time-nsecs\n");
>  		return -EINVAL;
>  	}
> @@ -1907,21 +1913,20 @@ static int stm32_adc_get_legacy_chan_count(struct iio_dev *indio_dev, struct stm
>  
>  static int stm32_adc_legacy_chan_init(struct iio_dev *indio_dev,
>  				      struct stm32_adc *adc,
> -				      struct iio_chan_spec *channels)
> +				      struct iio_chan_spec *channels,
> +				      int nchans)
>  {
> -	struct device_node *node = indio_dev->dev.of_node;
>  	const struct stm32_adc_info *adc_info = adc->cfg->adc_info;
>  	struct stm32_adc_diff_channel diff[STM32_ADC_CH_MAX];
> +	struct device *dev = &indio_dev->dev;
>  	u32 num_diff = adc->num_diff;
>  	int size = num_diff * sizeof(*diff) / sizeof(u32);
> -	int scan_index = 0, val, ret, i;
> -	struct property *prop;
> -	const __be32 *cur;
> -	u32 smp = 0;
> +	int scan_index = 0, ret, i, c;
> +	u32 smp = 0, smps[STM32_ADC_CH_MAX], chans[STM32_ADC_CH_MAX];
>  
>  	if (num_diff) {
> -		ret = of_property_read_u32_array(node, "st,adc-diff-channels",
> -						 (u32 *)diff, size);
> +		ret = device_property_read_u32_array(dev, "st,adc-diff-channels",
> +						     (u32 *)diff, size);
>  		if (ret) {
>  			dev_err(&indio_dev->dev, "Failed to get diff channels %d\n", ret);
>  			return ret;
> @@ -1942,32 +1947,47 @@ static int stm32_adc_legacy_chan_init(struct iio_dev *indio_dev,
>  		}
>  	}
>  
> -	of_property_for_each_u32(node, "st,adc-channels", prop, cur, val) {
> -		if (val >= adc_info->max_channels) {
> -			dev_err(&indio_dev->dev, "Invalid channel %d\n", val);
> +	ret = device_property_read_u32_array(dev, "st,adc-channels", chans,
> +					     nchans);
> +	if (ret)
> +		return ret;
> +
> +	for (c = 0; c < nchans; c++) {
> +		if (chans[c] >= adc_info->max_channels) {
> +			dev_err(&indio_dev->dev, "Invalid channel %d\n",
> +				chans[c]);
>  			return -EINVAL;
>  		}
>  
>  		/* Channel can't be configured both as single-ended & diff */
>  		for (i = 0; i < num_diff; i++) {
> -			if (val == diff[i].vinp) {
> -				dev_err(&indio_dev->dev, "channel %d misconfigured\n",	val);
> +			if (chans[c] == diff[i].vinp) {
> +				dev_err(&indio_dev->dev, "channel %d misconfigured\n",	chans[c]);
>  				return -EINVAL;
>  			}
>  		}
> -		stm32_adc_chan_init_one(indio_dev, &channels[scan_index], val,
> -					0, scan_index, false);
> +		stm32_adc_chan_init_one(indio_dev, &channels[scan_index],
> +					chans[c], 0, scan_index, false);
>  		scan_index++;
>  	}
>  
> +	if (adc->nsmps > 0) {
> +		ret = device_property_read_u32_array(dev, "st,min-sample-time-nsecs",
> +						     smps, adc->nsmps);
> +		if (ret)
> +			return ret;
> +	}
> +
>  	for (i = 0; i < scan_index; i++) {
>  		/*
> -		 * Using of_property_read_u32_index(), smp value will only be
> -		 * modified if valid u32 value can be decoded. This allows to
> -		 * get either no value, 1 shared value for all indexes, or one
> -		 * value per channel.
> +		 * This check is used with the above logic so that smp value
> +		 * will only be modified if valid u32 value can be decoded. This
> +		 * allows to get either no value, 1 shared value for all indexes,
> +		 * or one value per channel. The point is to have the same
> +		 * behavior as 'of_property_read_u32_index()'.
>  		 */
> -		of_property_read_u32_index(node, "st,min-sample-time-nsecs", i, &smp);
> +		if (i < adc->nsmps)
> +			smp = smps[i];
>  
>  		/* Prepare sampling time settings */
>  		stm32_adc_smpr_init(adc, channels[i].channel, smp);
> @@ -2010,22 +2030,21 @@ static int stm32_adc_generic_chan_init(struct iio_dev *indio_dev,
>  				       struct stm32_adc *adc,
>  				       struct iio_chan_spec *channels)
>  {
> -	struct device_node *node = indio_dev->dev.of_node;
>  	const struct stm32_adc_info *adc_info = adc->cfg->adc_info;
> -	struct device_node *child;
> +	struct fwnode_handle *child;
>  	const char *name;
>  	int val, scan_index = 0, ret;
>  	bool differential;
>  	u32 vin[2];
>  
> -	for_each_available_child_of_node(node, child) {
> -		ret = of_property_read_u32(child, "reg", &val);
> +	device_for_each_child_node(&indio_dev->dev, child) {
> +		ret = fwnode_property_read_u32(child, "reg", &val);
>  		if (ret) {
>  			dev_err(&indio_dev->dev, "Missing channel index %d\n", ret);
>  			goto err;
>  		}
>  
> -		ret = of_property_read_string(child, "label", &name);
> +		ret = fwnode_property_read_string(child, "label", &name);
>  		/* label is optional */
>  		if (!ret) {
>  			if (strlen(name) >= STM32_ADC_CH_SZ) {
> @@ -2050,7 +2069,7 @@ static int stm32_adc_generic_chan_init(struct iio_dev *indio_dev,
>  		}
>  
>  		differential = false;
> -		ret = of_property_read_u32_array(child, "diff-channels", vin, 2);
> +		ret = fwnode_property_read_u32_array(child, "diff-channels", vin, 2);
>  		/* diff-channels is optional */
>  		if (!ret) {
>  			differential = true;
> @@ -2067,7 +2086,7 @@ static int stm32_adc_generic_chan_init(struct iio_dev *indio_dev,
>  		stm32_adc_chan_init_one(indio_dev, &channels[scan_index], val,
>  					vin[1], scan_index, differential);
>  
> -		ret = of_property_read_u32(child, "st,min-sample-time-ns", &val);
> +		ret = fwnode_property_read_u32(child, "st,min-sample-time-ns", &val);
>  		/* st,min-sample-time-ns is optional */
>  		if (!ret) {
>  			stm32_adc_smpr_init(adc, channels[scan_index].channel, val);
> @@ -2085,14 +2104,13 @@ static int stm32_adc_generic_chan_init(struct iio_dev *indio_dev,
>  	return scan_index;
>  
>  err:
> -	of_node_put(child);
> +	fwnode_handle_put(child);
>  
>  	return ret;
>  }
>  
> -static int stm32_adc_chan_of_init(struct iio_dev *indio_dev, bool timestamping)
> +static int stm32_adc_chan_fw_init(struct iio_dev *indio_dev, bool timestamping)
>  {
> -	struct device_node *node = indio_dev->dev.of_node;
>  	struct stm32_adc *adc = iio_priv(indio_dev);
>  	const struct stm32_adc_info *adc_info = adc->cfg->adc_info;
>  	struct iio_chan_spec *channels;
> @@ -2102,7 +2120,7 @@ static int stm32_adc_chan_of_init(struct iio_dev *indio_dev, bool timestamping)
>  	for (i = 0; i < STM32_ADC_INT_CH_NB; i++)
>  		adc->int_ch[i] = STM32_ADC_INT_CH_NONE;
>  
> -	num_channels = of_get_available_child_count(node);
> +	num_channels = device_get_child_node_count(&indio_dev->dev);
>  	/* If no channels have been found, fallback to channels legacy properties. */
>  	if (!num_channels) {
>  		legacy = true;
> @@ -2133,7 +2151,8 @@ static int stm32_adc_chan_of_init(struct iio_dev *indio_dev, bool timestamping)
>  		return -ENOMEM;
>  
>  	if (legacy)
> -		ret = stm32_adc_legacy_chan_init(indio_dev, adc, channels);
> +		ret = stm32_adc_legacy_chan_init(indio_dev, adc, channels,
> +						 num_channels);
>  	else
>  		ret = stm32_adc_generic_chan_init(indio_dev, adc, channels);
>  	if (ret < 0)
> @@ -2215,9 +2234,6 @@ static int stm32_adc_probe(struct platform_device *pdev)
>  	bool timestamping = false;
>  	int ret;
>  
> -	if (!pdev->dev.of_node)
> -		return -ENODEV;
> -
>  	indio_dev = devm_iio_device_alloc(&pdev->dev, sizeof(*adc));
>  	if (!indio_dev)
>  		return -ENOMEM;
> @@ -2226,17 +2242,16 @@ static int stm32_adc_probe(struct platform_device *pdev)
>  	adc->common = dev_get_drvdata(pdev->dev.parent);
>  	spin_lock_init(&adc->lock);
>  	init_completion(&adc->completion);
> -	adc->cfg = (const struct stm32_adc_cfg *)
> -		of_match_device(dev->driver->of_match_table, dev)->data;
> +	adc->cfg = device_get_match_data(dev);
>  
>  	indio_dev->name = dev_name(&pdev->dev);
> -	indio_dev->dev.of_node = pdev->dev.of_node;
> +	device_set_node(&indio_dev->dev, dev_fwnode(&pdev->dev));
>  	indio_dev->info = &stm32_adc_iio_info;
>  	indio_dev->modes = INDIO_DIRECT_MODE | INDIO_HARDWARE_TRIGGERED;
>  
>  	platform_set_drvdata(pdev, indio_dev);
>  
> -	ret = of_property_read_u32(pdev->dev.of_node, "reg", &adc->offset);
> +	ret = device_property_read_u32(dev, "reg", &adc->offset);
>  	if (ret != 0) {
>  		dev_err(&pdev->dev, "missing reg property\n");
>  		return -EINVAL;
> @@ -2265,7 +2280,7 @@ static int stm32_adc_probe(struct platform_device *pdev)
>  		}
>  	}
>  
> -	ret = stm32_adc_of_get_resolution(indio_dev);
> +	ret = stm32_adc_fw_get_resolution(indio_dev);
>  	if (ret < 0)
>  		return ret;
>  
> @@ -2282,7 +2297,7 @@ static int stm32_adc_probe(struct platform_device *pdev)
>  		timestamping = true;
>  	}
>  
> -	ret = stm32_adc_chan_of_init(indio_dev, timestamping);
> +	ret = stm32_adc_chan_fw_init(indio_dev, timestamping);
>  	if (ret < 0)
>  		goto err_dma_disable;
>
Jonathan Cameron Aug. 6, 2022, 6:15 p.m. UTC | #2
On Fri, 15 Jul 2022 14:29:01 +0200
Nuno Sá <nuno.sa@analog.com> wrote:

> Make the conversion to firmware agnostic device properties. As part of
> the conversion the IIO inkern interface 'of_xlate()' is also converted to
> 'fwnode_xlate()'. The goal is to completely drop 'of_xlate' and hence OF
> dependencies from IIO.
> 
> Signed-off-by: Nuno Sá <nuno.sa@analog.com>
> Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
One query below. Otherwise LGTM (not that's true of the other patches I haven't
comment on at all)

> @@ -1885,8 +1887,12 @@ static int stm32_adc_get_legacy_chan_count(struct iio_dev *indio_dev, struct stm
>  		num_channels += ret;
>  	}
>  
> -	ret = of_property_count_elems_of_size(node, "st,adc-diff-channels",
> -					      sizeof(struct stm32_adc_diff_channel));
> +	/*
> +	 * each st,adc-diff-channels is a group of 2 u32 so we divide @ret
> +	 * to get the *real* number of channels.
> +	 */
> +	ret = device_property_count_u32(dev, "st,adc-diff-channels");

I think this can return an error code which should probably be handled.
More than possible that was true of original code though...

If it can't return an error for some reason I'm missing perhaps a
comment to explain why.

> +	ret /= (int)(sizeof(struct stm32_adc_diff_channel) / sizeof(u32));
>  	if (ret > adc_info->max_channels) {
>  		dev_err(&indio_dev->dev, "Bad st,adc-diff-channels?\n");
>  		return -EINVAL;
Jonathan Cameron Aug. 6, 2022, 6:53 p.m. UTC | #3
On Sat, 6 Aug 2022 19:15:38 +0100
Jonathan Cameron <jic23@kernel.org> wrote:

> On Fri, 15 Jul 2022 14:29:01 +0200
> Nuno Sá <nuno.sa@analog.com> wrote:
> 
> > Make the conversion to firmware agnostic device properties. As part of
> > the conversion the IIO inkern interface 'of_xlate()' is also converted to
> > 'fwnode_xlate()'. The goal is to completely drop 'of_xlate' and hence OF
> > dependencies from IIO.
> > 
> > Signed-off-by: Nuno Sá <nuno.sa@analog.com>
> > Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>  
> One query below. Otherwise LGTM (not that's true of the other patches I haven't
> comment on at all)
> 
> > @@ -1885,8 +1887,12 @@ static int stm32_adc_get_legacy_chan_count(struct iio_dev *indio_dev, struct stm
> >  		num_channels += ret;
> >  	}
> >  
> > -	ret = of_property_count_elems_of_size(node, "st,adc-diff-channels",
> > -					      sizeof(struct stm32_adc_diff_channel));
> > +	/*
> > +	 * each st,adc-diff-channels is a group of 2 u32 so we divide @ret
> > +	 * to get the *real* number of channels.
> > +	 */
> > +	ret = device_property_count_u32(dev, "st,adc-diff-channels");  
> 
> I think this can return an error code which should probably be handled.
> More than possible that was true of original code though...
> 
> If it can't return an error for some reason I'm missing perhaps a
> comment to explain why.

Given this was only outstanding question I stuck a conservative

if (ret < 0)
	return ret;
here whilst applying.

> 
> > +	ret /= (int)(sizeof(struct stm32_adc_diff_channel) / sizeof(u32));
> >  	if (ret > adc_info->max_channels) {
> >  		dev_err(&indio_dev->dev, "Bad st,adc-diff-channels?\n");
> >  		return -EINVAL;
diff mbox series

Patch

diff --git a/drivers/iio/adc/stm32-adc.c b/drivers/iio/adc/stm32-adc.c
index 3985fe972892..24248f1de1d0 100644
--- a/drivers/iio/adc/stm32-adc.c
+++ b/drivers/iio/adc/stm32-adc.c
@@ -21,11 +21,11 @@ 
 #include <linux/io.h>
 #include <linux/iopoll.h>
 #include <linux/module.h>
+#include <linux/mod_devicetable.h>
 #include <linux/nvmem-consumer.h>
 #include <linux/platform_device.h>
 #include <linux/pm_runtime.h>
-#include <linux/of.h>
-#include <linux/of_device.h>
+#include <linux/property.h>
 
 #include "stm32-adc-core.h"
 
@@ -241,6 +241,7 @@  struct stm32_adc_cfg {
  * @chan_name:		channel name array
  * @num_diff:		number of differential channels
  * @int_ch:		internal channel indexes array
+ * @nsmps:		number of channels with optional sample time
  */
 struct stm32_adc {
 	struct stm32_adc_common	*common;
@@ -267,6 +268,7 @@  struct stm32_adc {
 	char			chan_name[STM32_ADC_CH_MAX][STM32_ADC_CH_SZ];
 	u32			num_diff;
 	int			int_ch[STM32_ADC_INT_CH_NB];
+	int			nsmps;
 };
 
 struct stm32_adc_diff_channel {
@@ -1530,8 +1532,8 @@  static int stm32_adc_update_scan_mode(struct iio_dev *indio_dev,
 	return ret;
 }
 
-static int stm32_adc_of_xlate(struct iio_dev *indio_dev,
-			      const struct of_phandle_args *iiospec)
+static int stm32_adc_fwnode_xlate(struct iio_dev *indio_dev,
+				  const struct fwnode_reference_args *iiospec)
 {
 	int i;
 
@@ -1585,7 +1587,7 @@  static const struct iio_info stm32_adc_iio_info = {
 	.hwfifo_set_watermark = stm32_adc_set_watermark,
 	.update_scan_mode = stm32_adc_update_scan_mode,
 	.debugfs_reg_access = stm32_adc_debugfs_reg_access,
-	.of_xlate = stm32_adc_of_xlate,
+	.fwnode_xlate = stm32_adc_fwnode_xlate,
 };
 
 static unsigned int stm32_adc_dma_residue(struct stm32_adc *adc)
@@ -1782,14 +1784,14 @@  static const struct iio_chan_spec_ext_info stm32_adc_ext_info[] = {
 	{},
 };
 
-static int stm32_adc_of_get_resolution(struct iio_dev *indio_dev)
+static int stm32_adc_fw_get_resolution(struct iio_dev *indio_dev)
 {
-	struct device_node *node = indio_dev->dev.of_node;
+	struct device *dev = &indio_dev->dev;
 	struct stm32_adc *adc = iio_priv(indio_dev);
 	unsigned int i;
 	u32 res;
 
-	if (of_property_read_u32(node, "assigned-resolution-bits", &res))
+	if (device_property_read_u32(dev, "assigned-resolution-bits", &res))
 		res = adc->cfg->adc_info->resolutions[0];
 
 	for (i = 0; i < adc->cfg->adc_info->num_res; i++)
@@ -1873,11 +1875,11 @@  static void stm32_adc_chan_init_one(struct iio_dev *indio_dev,
 
 static int stm32_adc_get_legacy_chan_count(struct iio_dev *indio_dev, struct stm32_adc *adc)
 {
-	struct device_node *node = indio_dev->dev.of_node;
+	struct device *dev = &indio_dev->dev;
 	const struct stm32_adc_info *adc_info = adc->cfg->adc_info;
 	int num_channels = 0, ret;
 
-	ret = of_property_count_u32_elems(node, "st,adc-channels");
+	ret = device_property_count_u32(dev, "st,adc-channels");
 	if (ret > adc_info->max_channels) {
 		dev_err(&indio_dev->dev, "Bad st,adc-channels?\n");
 		return -EINVAL;
@@ -1885,8 +1887,12 @@  static int stm32_adc_get_legacy_chan_count(struct iio_dev *indio_dev, struct stm
 		num_channels += ret;
 	}
 
-	ret = of_property_count_elems_of_size(node, "st,adc-diff-channels",
-					      sizeof(struct stm32_adc_diff_channel));
+	/*
+	 * each st,adc-diff-channels is a group of 2 u32 so we divide @ret
+	 * to get the *real* number of channels.
+	 */
+	ret = device_property_count_u32(dev, "st,adc-diff-channels");
+	ret /= (int)(sizeof(struct stm32_adc_diff_channel) / sizeof(u32));
 	if (ret > adc_info->max_channels) {
 		dev_err(&indio_dev->dev, "Bad st,adc-diff-channels?\n");
 		return -EINVAL;
@@ -1896,8 +1902,8 @@  static int stm32_adc_get_legacy_chan_count(struct iio_dev *indio_dev, struct stm
 	}
 
 	/* Optional sample time is provided either for each, or all channels */
-	ret = of_property_count_u32_elems(node, "st,min-sample-time-nsecs");
-	if (ret > 1 && ret != num_channels) {
+	adc->nsmps = device_property_count_u32(dev, "st,min-sample-time-nsecs");
+	if (adc->nsmps > 1 && adc->nsmps != num_channels) {
 		dev_err(&indio_dev->dev, "Invalid st,min-sample-time-nsecs\n");
 		return -EINVAL;
 	}
@@ -1907,21 +1913,20 @@  static int stm32_adc_get_legacy_chan_count(struct iio_dev *indio_dev, struct stm
 
 static int stm32_adc_legacy_chan_init(struct iio_dev *indio_dev,
 				      struct stm32_adc *adc,
-				      struct iio_chan_spec *channels)
+				      struct iio_chan_spec *channels,
+				      int nchans)
 {
-	struct device_node *node = indio_dev->dev.of_node;
 	const struct stm32_adc_info *adc_info = adc->cfg->adc_info;
 	struct stm32_adc_diff_channel diff[STM32_ADC_CH_MAX];
+	struct device *dev = &indio_dev->dev;
 	u32 num_diff = adc->num_diff;
 	int size = num_diff * sizeof(*diff) / sizeof(u32);
-	int scan_index = 0, val, ret, i;
-	struct property *prop;
-	const __be32 *cur;
-	u32 smp = 0;
+	int scan_index = 0, ret, i, c;
+	u32 smp = 0, smps[STM32_ADC_CH_MAX], chans[STM32_ADC_CH_MAX];
 
 	if (num_diff) {
-		ret = of_property_read_u32_array(node, "st,adc-diff-channels",
-						 (u32 *)diff, size);
+		ret = device_property_read_u32_array(dev, "st,adc-diff-channels",
+						     (u32 *)diff, size);
 		if (ret) {
 			dev_err(&indio_dev->dev, "Failed to get diff channels %d\n", ret);
 			return ret;
@@ -1942,32 +1947,47 @@  static int stm32_adc_legacy_chan_init(struct iio_dev *indio_dev,
 		}
 	}
 
-	of_property_for_each_u32(node, "st,adc-channels", prop, cur, val) {
-		if (val >= adc_info->max_channels) {
-			dev_err(&indio_dev->dev, "Invalid channel %d\n", val);
+	ret = device_property_read_u32_array(dev, "st,adc-channels", chans,
+					     nchans);
+	if (ret)
+		return ret;
+
+	for (c = 0; c < nchans; c++) {
+		if (chans[c] >= adc_info->max_channels) {
+			dev_err(&indio_dev->dev, "Invalid channel %d\n",
+				chans[c]);
 			return -EINVAL;
 		}
 
 		/* Channel can't be configured both as single-ended & diff */
 		for (i = 0; i < num_diff; i++) {
-			if (val == diff[i].vinp) {
-				dev_err(&indio_dev->dev, "channel %d misconfigured\n",	val);
+			if (chans[c] == diff[i].vinp) {
+				dev_err(&indio_dev->dev, "channel %d misconfigured\n",	chans[c]);
 				return -EINVAL;
 			}
 		}
-		stm32_adc_chan_init_one(indio_dev, &channels[scan_index], val,
-					0, scan_index, false);
+		stm32_adc_chan_init_one(indio_dev, &channels[scan_index],
+					chans[c], 0, scan_index, false);
 		scan_index++;
 	}
 
+	if (adc->nsmps > 0) {
+		ret = device_property_read_u32_array(dev, "st,min-sample-time-nsecs",
+						     smps, adc->nsmps);
+		if (ret)
+			return ret;
+	}
+
 	for (i = 0; i < scan_index; i++) {
 		/*
-		 * Using of_property_read_u32_index(), smp value will only be
-		 * modified if valid u32 value can be decoded. This allows to
-		 * get either no value, 1 shared value for all indexes, or one
-		 * value per channel.
+		 * This check is used with the above logic so that smp value
+		 * will only be modified if valid u32 value can be decoded. This
+		 * allows to get either no value, 1 shared value for all indexes,
+		 * or one value per channel. The point is to have the same
+		 * behavior as 'of_property_read_u32_index()'.
 		 */
-		of_property_read_u32_index(node, "st,min-sample-time-nsecs", i, &smp);
+		if (i < adc->nsmps)
+			smp = smps[i];
 
 		/* Prepare sampling time settings */
 		stm32_adc_smpr_init(adc, channels[i].channel, smp);
@@ -2010,22 +2030,21 @@  static int stm32_adc_generic_chan_init(struct iio_dev *indio_dev,
 				       struct stm32_adc *adc,
 				       struct iio_chan_spec *channels)
 {
-	struct device_node *node = indio_dev->dev.of_node;
 	const struct stm32_adc_info *adc_info = adc->cfg->adc_info;
-	struct device_node *child;
+	struct fwnode_handle *child;
 	const char *name;
 	int val, scan_index = 0, ret;
 	bool differential;
 	u32 vin[2];
 
-	for_each_available_child_of_node(node, child) {
-		ret = of_property_read_u32(child, "reg", &val);
+	device_for_each_child_node(&indio_dev->dev, child) {
+		ret = fwnode_property_read_u32(child, "reg", &val);
 		if (ret) {
 			dev_err(&indio_dev->dev, "Missing channel index %d\n", ret);
 			goto err;
 		}
 
-		ret = of_property_read_string(child, "label", &name);
+		ret = fwnode_property_read_string(child, "label", &name);
 		/* label is optional */
 		if (!ret) {
 			if (strlen(name) >= STM32_ADC_CH_SZ) {
@@ -2050,7 +2069,7 @@  static int stm32_adc_generic_chan_init(struct iio_dev *indio_dev,
 		}
 
 		differential = false;
-		ret = of_property_read_u32_array(child, "diff-channels", vin, 2);
+		ret = fwnode_property_read_u32_array(child, "diff-channels", vin, 2);
 		/* diff-channels is optional */
 		if (!ret) {
 			differential = true;
@@ -2067,7 +2086,7 @@  static int stm32_adc_generic_chan_init(struct iio_dev *indio_dev,
 		stm32_adc_chan_init_one(indio_dev, &channels[scan_index], val,
 					vin[1], scan_index, differential);
 
-		ret = of_property_read_u32(child, "st,min-sample-time-ns", &val);
+		ret = fwnode_property_read_u32(child, "st,min-sample-time-ns", &val);
 		/* st,min-sample-time-ns is optional */
 		if (!ret) {
 			stm32_adc_smpr_init(adc, channels[scan_index].channel, val);
@@ -2085,14 +2104,13 @@  static int stm32_adc_generic_chan_init(struct iio_dev *indio_dev,
 	return scan_index;
 
 err:
-	of_node_put(child);
+	fwnode_handle_put(child);
 
 	return ret;
 }
 
-static int stm32_adc_chan_of_init(struct iio_dev *indio_dev, bool timestamping)
+static int stm32_adc_chan_fw_init(struct iio_dev *indio_dev, bool timestamping)
 {
-	struct device_node *node = indio_dev->dev.of_node;
 	struct stm32_adc *adc = iio_priv(indio_dev);
 	const struct stm32_adc_info *adc_info = adc->cfg->adc_info;
 	struct iio_chan_spec *channels;
@@ -2102,7 +2120,7 @@  static int stm32_adc_chan_of_init(struct iio_dev *indio_dev, bool timestamping)
 	for (i = 0; i < STM32_ADC_INT_CH_NB; i++)
 		adc->int_ch[i] = STM32_ADC_INT_CH_NONE;
 
-	num_channels = of_get_available_child_count(node);
+	num_channels = device_get_child_node_count(&indio_dev->dev);
 	/* If no channels have been found, fallback to channels legacy properties. */
 	if (!num_channels) {
 		legacy = true;
@@ -2133,7 +2151,8 @@  static int stm32_adc_chan_of_init(struct iio_dev *indio_dev, bool timestamping)
 		return -ENOMEM;
 
 	if (legacy)
-		ret = stm32_adc_legacy_chan_init(indio_dev, adc, channels);
+		ret = stm32_adc_legacy_chan_init(indio_dev, adc, channels,
+						 num_channels);
 	else
 		ret = stm32_adc_generic_chan_init(indio_dev, adc, channels);
 	if (ret < 0)
@@ -2215,9 +2234,6 @@  static int stm32_adc_probe(struct platform_device *pdev)
 	bool timestamping = false;
 	int ret;
 
-	if (!pdev->dev.of_node)
-		return -ENODEV;
-
 	indio_dev = devm_iio_device_alloc(&pdev->dev, sizeof(*adc));
 	if (!indio_dev)
 		return -ENOMEM;
@@ -2226,17 +2242,16 @@  static int stm32_adc_probe(struct platform_device *pdev)
 	adc->common = dev_get_drvdata(pdev->dev.parent);
 	spin_lock_init(&adc->lock);
 	init_completion(&adc->completion);
-	adc->cfg = (const struct stm32_adc_cfg *)
-		of_match_device(dev->driver->of_match_table, dev)->data;
+	adc->cfg = device_get_match_data(dev);
 
 	indio_dev->name = dev_name(&pdev->dev);
-	indio_dev->dev.of_node = pdev->dev.of_node;
+	device_set_node(&indio_dev->dev, dev_fwnode(&pdev->dev));
 	indio_dev->info = &stm32_adc_iio_info;
 	indio_dev->modes = INDIO_DIRECT_MODE | INDIO_HARDWARE_TRIGGERED;
 
 	platform_set_drvdata(pdev, indio_dev);
 
-	ret = of_property_read_u32(pdev->dev.of_node, "reg", &adc->offset);
+	ret = device_property_read_u32(dev, "reg", &adc->offset);
 	if (ret != 0) {
 		dev_err(&pdev->dev, "missing reg property\n");
 		return -EINVAL;
@@ -2265,7 +2280,7 @@  static int stm32_adc_probe(struct platform_device *pdev)
 		}
 	}
 
-	ret = stm32_adc_of_get_resolution(indio_dev);
+	ret = stm32_adc_fw_get_resolution(indio_dev);
 	if (ret < 0)
 		return ret;
 
@@ -2282,7 +2297,7 @@  static int stm32_adc_probe(struct platform_device *pdev)
 		timestamping = true;
 	}
 
-	ret = stm32_adc_chan_of_init(indio_dev, timestamping);
+	ret = stm32_adc_chan_fw_init(indio_dev, timestamping);
 	if (ret < 0)
 		goto err_dma_disable;