From: Matti Vaittinen Date: Mon, 24 Mar 2025 07:13:28 +0000 (+0200) Subject: iio: adc: sun20i-gpadc: Use adc-helpers X-Git-Tag: v6.16-rc1~30^2~4^2~230 X-Git-Url: https://git.kernel.dk/?a=commitdiff_plain;h=19d8a8691869463558349327f9aa1ab3788e696e;p=linux-block.git iio: adc: sun20i-gpadc: Use adc-helpers The new devm_iio_adc_device_alloc_chaninfo_se() -helper is intended to help drivers avoid open-coding the for_each_node -loop for getting the channel IDs. The helper provides standard way to detect the ADC channel nodes (by the node name), and a standard way to convert the "reg" -properties to channel identification numbers, used in the struct iio_chan_spec. Furthermore, the helper can optionally check the found channel IDs are smaller than given maximum. This is useful for callers which later use the IDs for example for indexing a channel data array. The original driver treated all found child nodes as channel nodes. The new helper requires channel nodes to be named channel[@N]. This should help avoid problems with devices which may contain also other but ADC child nodes. Quick grep from arch/* with the sun20i-gpadc's compatible string didn't reveal any in-tree .dts with channel nodes named otherwise. Also, same grep shows all the in-tree .dts seem to have channel IDs between 0..num of channels. Use the new helper. Signed-off-by: Matti Vaittinen Reviewed-by: Andy Shevchenko Link: https://patch.msgid.link/e367a803c0d625e60c9fca16c55a25eee06b5a89.1742560649.git.mazziesaccount@gmail.com Signed-off-by: Jonathan Cameron --- diff --git a/drivers/iio/adc/Kconfig b/drivers/iio/adc/Kconfig index 57ea8cd464ca..5089d95d6a00 100644 --- a/drivers/iio/adc/Kconfig +++ b/drivers/iio/adc/Kconfig @@ -1401,6 +1401,7 @@ config SUN4I_GPADC config SUN20I_GPADC tristate "Allwinner D1/T113s/T507/R329 and similar GPADCs driver" depends on ARCH_SUNXI || COMPILE_TEST + select IIO_ADC_HELPER help Say yes here to build support for Allwinner (D1, T113, T507 and R329) SoCs GPADC. This ADC provides up to 16 channels. diff --git a/drivers/iio/adc/sun20i-gpadc-iio.c b/drivers/iio/adc/sun20i-gpadc-iio.c index 136b8d9c294f..2428ea69d676 100644 --- a/drivers/iio/adc/sun20i-gpadc-iio.c +++ b/drivers/iio/adc/sun20i-gpadc-iio.c @@ -15,6 +15,7 @@ #include #include +#include #include #define SUN20I_GPADC_DRIVER_NAME "sun20i-gpadc" @@ -149,36 +150,23 @@ static void sun20i_gpadc_reset_assert(void *data) reset_control_assert(rst); } +static const struct iio_chan_spec sun20i_gpadc_chan_template = { + .type = IIO_VOLTAGE, + .indexed = 1, + .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), + .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE), +}; + static int sun20i_gpadc_alloc_channels(struct iio_dev *indio_dev, struct device *dev) { - unsigned int channel; - int num_channels, i, ret; + int num_channels; struct iio_chan_spec *channels; - num_channels = device_get_child_node_count(dev); - if (num_channels == 0) - return dev_err_probe(dev, -ENODEV, "no channel children\n"); - - channels = devm_kcalloc(dev, num_channels, sizeof(*channels), - GFP_KERNEL); - if (!channels) - return -ENOMEM; - - i = 0; - device_for_each_child_node_scoped(dev, node) { - ret = fwnode_property_read_u32(node, "reg", &channel); - if (ret) - return dev_err_probe(dev, ret, "invalid channel number\n"); - - channels[i].type = IIO_VOLTAGE; - channels[i].indexed = 1; - channels[i].channel = channel; - channels[i].info_mask_separate = BIT(IIO_CHAN_INFO_RAW); - channels[i].info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE); - - i++; - } + num_channels = devm_iio_adc_device_alloc_chaninfo_se(dev, + &sun20i_gpadc_chan_template, -1, &channels); + if (num_channels < 0) + return num_channels; indio_dev->channels = channels; indio_dev->num_channels = num_channels; @@ -271,3 +259,4 @@ module_platform_driver(sun20i_gpadc_driver); MODULE_DESCRIPTION("ADC driver for sunxi platforms"); MODULE_AUTHOR("Maksim Kiselev "); MODULE_LICENSE("GPL"); +MODULE_IMPORT_NS("IIO_DRIVER");