Commit 95bc8184 authored by Olivier Moysan's avatar Olivier Moysan Committed by Jonathan Cameron
Browse files

iio: adc: stm32-adc: add support of generic channels binding 



Add support of generic IIO channel binding:
./devicetree/bindings/iio/adc/adc.yaml
Keep support of st,adc-channels and st,adc-diff-channels
for backward compatibility.

Signed-off-by: default avatarOlivier Moysan <olivier.moysan@foss.st.com>
Reviewed-by: default avatarFabrice Gasnier <fabrice.gasnier@foss.st.com>
Link: https://lore.kernel.org/r/20211014131228.4692-5-olivier.moysan@foss.st.com


Signed-off-by: default avatarJonathan Cameron <Jonathan.Cameron@huawei.com>
parent 45571a36

drivers/iio/adc/stm32-adc.c

+86 −9
Original line number Diff line number Diff line
@@ -35,7 +35,7 @@ 
#define STM32H7_BOOST_CLKRATE		20000000UL



#define STM32_ADC_CH_MAX		20	/* max number of channels */

#define STM32_ADC_CH_SZ			10	/* max channel name size */

#define STM32_ADC_CH_SZ			16	/* max channel name size */

#define STM32_ADC_MAX_SQ		16	/* SQ1..SQ16 */

#define STM32_ADC_MAX_SMP		7	/* SMPx range is [0..7] */

#define STM32_ADC_TIMEOUT_US		100000
@@ -1792,6 +1792,73 @@ static int stm32_adc_legacy_chan_init(struct iio_dev *indio_dev, 
	return scan_index;

}



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;

	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);

		if (ret) {

			dev_err(&indio_dev->dev, "Missing channel index %d\n", ret);

			goto err;

		}



		ret = of_property_read_string(child, "label", &name);

		/* label is optional */

		if (!ret) {

			if (strlen(name) >= STM32_ADC_CH_SZ) {

				dev_err(&indio_dev->dev, "Label %s exceeds %d characters\n",

					name, STM32_ADC_CH_SZ);

				return -EINVAL;

			}

			strncpy(adc->chan_name[val], name, STM32_ADC_CH_SZ);

		} else if (ret != -EINVAL) {

			dev_err(&indio_dev->dev, "Invalid label %d\n", ret);

			goto err;

		}



		if (val >= adc_info->max_channels) {

			dev_err(&indio_dev->dev, "Invalid channel %d\n", val);

			ret = -EINVAL;

			goto err;

		}



		differential = false;

		ret = of_property_read_u32_array(child, "diff-channels", vin, 2);

		/* diff-channels is optional */

		if (!ret) {

			differential = true;

			if (vin[0] != val || vin[1] >= adc_info->max_channels) {

				dev_err(&indio_dev->dev, "Invalid channel in%d-in%d\n",

					vin[0], vin[1]);

				goto err;

			}

		} else if (ret != -EINVAL) {

			dev_err(&indio_dev->dev, "Invalid diff-channels property %d\n", ret);

			goto err;

		}



		stm32_adc_chan_init_one(indio_dev, &channels[scan_index], val,

					vin[1], scan_index, differential);

		scan_index++;

	}



	return scan_index;



err:

	of_node_put(child);



	return ret;

}



static int stm32_adc_chan_of_init(struct iio_dev *indio_dev, bool timestamping)

{

	struct device_node *node = indio_dev->dev.of_node;
@@ -1800,15 +1867,22 @@ static int stm32_adc_chan_of_init(struct iio_dev *indio_dev, bool timestamping) 
	struct iio_chan_spec *channels;

	int scan_index = 0, num_channels = 0, ret, i;

	u32 smp = 0;

	bool legacy = false;



	num_channels = of_get_available_child_count(node);

	/* If no channels have been found, fallback to channels legacy properties. */

	if (!num_channels) {

		legacy = true;



		ret = stm32_adc_get_legacy_chan_count(indio_dev, adc);

	if (ret < 0)

		if (!ret) {

			dev_err(indio_dev->dev.parent, "No channel found\n");

			return -ENODATA;

		} else if (ret < 0) {

			return ret;

	num_channels = ret;

		}



	if (!num_channels) {

		dev_err(&indio_dev->dev, "No channels configured\n");

		return -ENODATA;

		num_channels = ret;

	}



	if (num_channels > adc_info->max_channels) {
@@ -1832,7 +1906,10 @@ static int stm32_adc_chan_of_init(struct iio_dev *indio_dev, bool timestamping) 
	if (!channels)

		return -ENOMEM;



	if (legacy)

		ret = stm32_adc_legacy_chan_init(indio_dev, adc, channels);

	else

		ret = stm32_adc_generic_chan_init(indio_dev, adc, channels);

	if (ret < 0)

		return ret;

	scan_index = ret;