diff options
Diffstat (limited to 'drivers/iio/dac/rohm-bd79703.c')
| -rw-r--r-- | drivers/iio/dac/rohm-bd79703.c | 246 |
1 files changed, 246 insertions, 0 deletions
diff --git a/drivers/iio/dac/rohm-bd79703.c b/drivers/iio/dac/rohm-bd79703.c new file mode 100644 index 000000000000..e91090e4a66d --- /dev/null +++ b/drivers/iio/dac/rohm-bd79703.c @@ -0,0 +1,246 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * BD79703 ROHM Digital to Analog converter + * + * Copyright (c) 2024, ROHM Semiconductor. + */ + +#include <linux/bits.h> +#include <linux/device.h> +#include <linux/module.h> +#include <linux/regmap.h> +#include <linux/regulator/consumer.h> +#include <linux/spi/spi.h> +#include <linux/iio/iio.h> + +#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_MAPLE, +}; + +/* 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 <mazziesaccount@gmail.com>"); +MODULE_DESCRIPTION("ROHM BD79703 DAC driver"); +MODULE_LICENSE("GPL"); |