// SPDX-License-Identifier: GPL-2.0-only /* * BD79703 ROHM Digital to Analog converter * * Copyright (c) 2024, ROHM Semiconductor. */ #include #include #include #include #include #include #include #define BD79703_MAX_REGISTER 0xf #define BD79703_DAC_BITS 8 #define BD79703_REG_OUT_ALL GENMASK(2, 0) /* * The BD79703 uses 12-bit SPI commands. First four bits (high bits) define * channel(s) which are operated on, and also the mode. The mode can be to set * a DAC word only, or set DAC word and output. The data-sheet is not very * specific on how a previously set DAC word can be 'taken in to use'. Thus * this driver only uses the 'set DAC and output it' -mode. * * The BD79703 latches last 12-bits when the chip-select is toggled. Thus we * can use 16-bit transfers which should be widely supported. To simplify this * further, we treat the last 8 bits as a value, and first 8 bits as an * address. This allows us to separate channels/mode by address and treat the * 8-bit register value as DAC word. The highest 4 bits of address will be * discarded when the transfer is latched. */ static const struct regmap_config bd79703_regmap_config = { .reg_bits = 8, .val_bits = 8, .max_register = BD79703_MAX_REGISTER, .cache_type = REGCACHE_RBTREE, }; /* Dynamic driver private data */ struct bd79703_data { struct regmap *regmap; int vfs; }; /* Static, IC type specific data for different variants */ struct bd7970x_chip_data { const char *name; const struct iio_chan_spec *channels; int num_channels; bool has_vfs; }; static int bd79703_read_raw(struct iio_dev *idev, struct iio_chan_spec const *chan, int *val, int *val2, long mask) { struct bd79703_data *data = iio_priv(idev); if (mask != IIO_CHAN_INFO_SCALE) return -EINVAL; *val = data->vfs / 1000; *val2 = BD79703_DAC_BITS; return IIO_VAL_FRACTIONAL_LOG2; } static int bd79703_write_raw(struct iio_dev *idev, struct iio_chan_spec const *chan, int val, int val2, long mask) { struct bd79703_data *data = iio_priv(idev); if (val < 0 || val >= 1 << BD79703_DAC_BITS) return -EINVAL; return regmap_write(data->regmap, chan->address, val); }; static const struct iio_info bd79703_info = { .read_raw = bd79703_read_raw, .write_raw = bd79703_write_raw, }; #define BD79703_CHAN_ADDR(_chan, _addr) { \ .type = IIO_VOLTAGE, \ .indexed = 1, \ .output = 1, \ .channel = (_chan), \ .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \ .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE), \ .address = (_addr), \ } #define BD79703_CHAN(_chan) BD79703_CHAN_ADDR((_chan), (_chan) + 1) static const struct iio_chan_spec bd79700_channels[] = { BD79703_CHAN(0), BD79703_CHAN(1), }; static const struct iio_chan_spec bd79701_channels[] = { BD79703_CHAN(0), BD79703_CHAN(1), BD79703_CHAN(2), }; /* * The BD79702 has 4 channels. They aren't mapped to BD79703 channels 0, 1, 2 * and 3, but to the channels 0, 1, 4, 5. So the addressing used with SPI * accesses is 1, 2, 5 and 6 for them. Thus, they're not constant offset to * the channel number as with other IC variants. */ static const struct iio_chan_spec bd79702_channels[] = { BD79703_CHAN_ADDR(0, 1), BD79703_CHAN_ADDR(1, 2), BD79703_CHAN_ADDR(2, 5), BD79703_CHAN_ADDR(3, 6), }; static const struct iio_chan_spec bd79703_channels[] = { BD79703_CHAN(0), BD79703_CHAN(1), BD79703_CHAN(2), BD79703_CHAN(3), BD79703_CHAN(4), BD79703_CHAN(5), }; static const struct bd7970x_chip_data bd79700_chip_data = { .name = "bd79700", .channels = bd79700_channels, .num_channels = ARRAY_SIZE(bd79700_channels), .has_vfs = false, }; static const struct bd7970x_chip_data bd79701_chip_data = { .name = "bd79701", .channels = bd79701_channels, .num_channels = ARRAY_SIZE(bd79701_channels), .has_vfs = false, }; static const struct bd7970x_chip_data bd79702_chip_data = { .name = "bd79702", .channels = bd79702_channels, .num_channels = ARRAY_SIZE(bd79702_channels), .has_vfs = true, }; static const struct bd7970x_chip_data bd79703_chip_data = { .name = "bd79703", .channels = bd79703_channels, .num_channels = ARRAY_SIZE(bd79703_channels), .has_vfs = true, }; static int bd79703_probe(struct spi_device *spi) { const struct bd7970x_chip_data *cd; struct device *dev = &spi->dev; struct bd79703_data *data; struct iio_dev *idev; int ret; cd = spi_get_device_match_data(spi); if (!cd) return -ENODEV; idev = devm_iio_device_alloc(dev, sizeof(*data)); if (!idev) return -ENOMEM; data = iio_priv(idev); data->regmap = devm_regmap_init_spi(spi, &bd79703_regmap_config); if (IS_ERR(data->regmap)) return dev_err_probe(dev, PTR_ERR(data->regmap), "Failed to initialize Regmap\n"); /* * BD79703 has a separate VFS pin, whereas the BD79700 and BD79701 use * VCC for their full-scale output voltage. */ if (cd->has_vfs) { ret = devm_regulator_get_enable(dev, "vcc"); if (ret) return dev_err_probe(dev, ret, "Failed to enable VCC\n"); ret = devm_regulator_get_enable_read_voltage(dev, "vfs"); if (ret < 0) return dev_err_probe(dev, ret, "Failed to get Vfs\n"); } else { ret = devm_regulator_get_enable_read_voltage(dev, "vcc"); if (ret < 0) return dev_err_probe(dev, ret, "Failed to get VCC\n"); } data->vfs = ret; idev->channels = cd->channels; idev->num_channels = cd->num_channels; idev->modes = INDIO_DIRECT_MODE; idev->info = &bd79703_info; idev->name = cd->name; /* Initialize all to output zero */ ret = regmap_write(data->regmap, BD79703_REG_OUT_ALL, 0); if (ret) return ret; return devm_iio_device_register(dev, idev); } static const struct spi_device_id bd79703_id[] = { { "bd79700", (kernel_ulong_t)&bd79700_chip_data }, { "bd79701", (kernel_ulong_t)&bd79701_chip_data }, { "bd79702", (kernel_ulong_t)&bd79702_chip_data }, { "bd79703", (kernel_ulong_t)&bd79703_chip_data }, { } }; MODULE_DEVICE_TABLE(spi, bd79703_id); static const struct of_device_id bd79703_of_match[] = { { .compatible = "rohm,bd79700", .data = &bd79700_chip_data }, { .compatible = "rohm,bd79701", .data = &bd79701_chip_data }, { .compatible = "rohm,bd79702", .data = &bd79702_chip_data }, { .compatible = "rohm,bd79703", .data = &bd79703_chip_data }, { } }; MODULE_DEVICE_TABLE(of, bd79703_of_match); static struct spi_driver bd79703_driver = { .driver = { .name = "bd79703", .of_match_table = bd79703_of_match, }, .probe = bd79703_probe, .id_table = bd79703_id, }; module_spi_driver(bd79703_driver); MODULE_AUTHOR("Matti Vaittinen "); MODULE_DESCRIPTION("ROHM BD79703 DAC driver"); MODULE_LICENSE("GPL");