// SPDX-License-Identifier: GPL-2.0-only /* * Analog Devices AD7405 driver * * Copyright 2025 Analog Devices Inc. */ #include #include #include #include #include #include #include #include #include #include #include #include static const unsigned int ad7405_dec_rates_range[] = { 32, 1, 4096, }; struct ad7405_chip_info { const char *name; const unsigned int full_scale_mv; }; struct ad7405_state { struct iio_backend *back; const struct ad7405_chip_info *info; unsigned int ref_frequency; unsigned int dec_rate; }; static int ad7405_set_dec_rate(struct iio_dev *indio_dev, const struct iio_chan_spec *chan, unsigned int dec_rate) { struct ad7405_state *st = iio_priv(indio_dev); int ret; if (dec_rate > 4096 || dec_rate < 32) return -EINVAL; if (!iio_device_claim_direct(indio_dev)) return -EBUSY; ret = iio_backend_oversampling_ratio_set(st->back, chan->scan_index, dec_rate); iio_device_release_direct(indio_dev); if (ret < 0) return ret; st->dec_rate = dec_rate; return 0; } static int ad7405_read_raw(struct iio_dev *indio_dev, const struct iio_chan_spec *chan, int *val, int *val2, long info) { struct ad7405_state *st = iio_priv(indio_dev); switch (info) { case IIO_CHAN_INFO_SCALE: *val = st->info->full_scale_mv; *val2 = indio_dev->channels[0].scan_type.realbits - 1; return IIO_VAL_FRACTIONAL_LOG2; case IIO_CHAN_INFO_OVERSAMPLING_RATIO: *val = st->dec_rate; return IIO_VAL_INT; case IIO_CHAN_INFO_SAMP_FREQ: *val = DIV_ROUND_CLOSEST_ULL(st->ref_frequency, st->dec_rate); return IIO_VAL_INT; case IIO_CHAN_INFO_OFFSET: *val = -(1 << (indio_dev->channels[0].scan_type.realbits - 1)); return IIO_VAL_INT; default: return -EINVAL; } } static int ad7405_write_raw(struct iio_dev *indio_dev, struct iio_chan_spec const *chan, int val, int val2, long info) { switch (info) { case IIO_CHAN_INFO_OVERSAMPLING_RATIO: if (val < 0) return -EINVAL; return ad7405_set_dec_rate(indio_dev, chan, val); default: return -EINVAL; } } static int ad7405_read_avail(struct iio_dev *indio_dev, struct iio_chan_spec const *chan, const int **vals, int *type, int *length, long info) { switch (info) { case IIO_CHAN_INFO_OVERSAMPLING_RATIO: *vals = ad7405_dec_rates_range; *type = IIO_VAL_INT; return IIO_AVAIL_RANGE; default: return -EINVAL; } } static const struct iio_info ad7405_iio_info = { .read_raw = &ad7405_read_raw, .write_raw = &ad7405_write_raw, .read_avail = &ad7405_read_avail, }; static const struct iio_chan_spec ad7405_channel = { .type = IIO_VOLTAGE, .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE) | BIT(IIO_CHAN_INFO_OFFSET), .info_mask_shared_by_all = IIO_CHAN_INFO_SAMP_FREQ | BIT(IIO_CHAN_INFO_OVERSAMPLING_RATIO), .info_mask_shared_by_all_available = BIT(IIO_CHAN_INFO_OVERSAMPLING_RATIO), .indexed = 1, .channel = 0, .channel2 = 1, .differential = 1, .scan_index = 0, .scan_type = { .sign = 'u', .realbits = 16, .storagebits = 16, }, }; static const struct ad7405_chip_info ad7405_chip_info = { .name = "ad7405", .full_scale_mv = 320, }; static const struct ad7405_chip_info adum7701_chip_info = { .name = "adum7701", .full_scale_mv = 320, }; static const struct ad7405_chip_info adum7702_chip_info = { .name = "adum7702", .full_scale_mv = 64, }; static const struct ad7405_chip_info adum7703_chip_info = { .name = "adum7703", .full_scale_mv = 320, }; static const char * const ad7405_power_supplies[] = { "vdd1", "vdd2", }; static int ad7405_probe(struct platform_device *pdev) { struct device *dev = &pdev->dev; struct iio_dev *indio_dev; struct ad7405_state *st; struct clk *clk; int ret; indio_dev = devm_iio_device_alloc(dev, sizeof(*st)); if (!indio_dev) return -ENOMEM; st = iio_priv(indio_dev); st->info = device_get_match_data(dev); if (!st->info) return dev_err_probe(dev, -EINVAL, "no chip info\n"); ret = devm_regulator_bulk_get_enable(dev, ARRAY_SIZE(ad7405_power_supplies), ad7405_power_supplies); if (ret) return dev_err_probe(dev, ret, "failed to get and enable supplies"); clk = devm_clk_get_enabled(dev, NULL); if (IS_ERR(clk)) return PTR_ERR(clk); st->ref_frequency = clk_get_rate(clk); if (!st->ref_frequency) return -EINVAL; indio_dev->name = st->info->name; indio_dev->channels = &ad7405_channel; indio_dev->num_channels = 1; indio_dev->info = &ad7405_iio_info; st->back = devm_iio_backend_get(dev, NULL); if (IS_ERR(st->back)) return dev_err_probe(dev, PTR_ERR(st->back), "failed to get IIO backend"); ret = iio_backend_chan_enable(st->back, 0); if (ret) return ret; ret = devm_iio_backend_request_buffer(dev, st->back, indio_dev); if (ret) return ret; ret = devm_iio_backend_enable(dev, st->back); if (ret) return ret; /* * Set 256 decimation rate. The default value in the AXI_ADC register * is 0, so we set the register with a decimation rate value that is * functional for all parts. */ ret = ad7405_set_dec_rate(indio_dev, &indio_dev->channels[0], 256); if (ret) return ret; return devm_iio_device_register(dev, indio_dev); } static const struct of_device_id ad7405_of_match[] = { { .compatible = "adi,ad7405", .data = &ad7405_chip_info, }, { .compatible = "adi,adum7701", .data = &adum7701_chip_info, }, { .compatible = "adi,adum7702", .data = &adum7702_chip_info, }, { .compatible = "adi,adum7703", .data = &adum7703_chip_info, }, { } }; MODULE_DEVICE_TABLE(of, ad7405_of_match); static struct platform_driver ad7405_driver = { .driver = { .name = "ad7405", .of_match_table = ad7405_of_match, }, .probe = ad7405_probe, }; module_platform_driver(ad7405_driver); MODULE_AUTHOR("Dragos Bogdan "); MODULE_AUTHOR("Pop Ioan Daniel "); MODULE_DESCRIPTION("Analog Devices AD7405 driver"); MODULE_LICENSE("GPL"); MODULE_IMPORT_NS("IIO_BACKEND");