From 95bc818404b2c1a61611365ecf434a52f01ee97d Mon Sep 17 00:00:00 2001 From: Olivier Moysan Date: Thu, 14 Oct 2021 15:12:25 +0200 Subject: 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: Olivier Moysan Reviewed-by: Fabrice Gasnier Link: https://lore.kernel.org/r/20211014131228.4692-5-olivier.moysan@foss.st.com Signed-off-by: Jonathan Cameron --- drivers/iio/adc/stm32-adc.c | 95 ++++++++++++++++++++++++++++++++++++++++----- 1 file changed, 86 insertions(+), 9 deletions(-) (limited to 'drivers/iio') diff --git a/drivers/iio/adc/stm32-adc.c b/drivers/iio/adc/stm32-adc.c index 2f137d14f141..85d09cbd41ae 100644 --- a/drivers/iio/adc/stm32-adc.c +++ b/drivers/iio/adc/stm32-adc.c @@ -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; - ret = stm32_adc_get_legacy_chan_count(indio_dev, adc); - if (ret < 0) - return ret; - num_channels = ret; - + num_channels = of_get_available_child_count(node); + /* If no channels have been found, fallback to channels legacy properties. */ if (!num_channels) { - dev_err(&indio_dev->dev, "No channels configured\n"); - return -ENODATA; + legacy = true; + + ret = stm32_adc_get_legacy_chan_count(indio_dev, adc); + 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 > 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; - ret = stm32_adc_legacy_chan_init(indio_dev, adc, channels); + 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; -- cgit v1.2.3