diff options
Diffstat (limited to 'drivers/iio/dac/max5522.c')
| -rw-r--r-- | drivers/iio/dac/max5522.c | 207 |
1 files changed, 207 insertions, 0 deletions
diff --git a/drivers/iio/dac/max5522.c b/drivers/iio/dac/max5522.c new file mode 100644 index 0000000000..05034a3065 --- /dev/null +++ b/drivers/iio/dac/max5522.c @@ -0,0 +1,207 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Maxim MAX5522 + * Dual, Ultra-Low-Power 10-Bit, Voltage-Output DACs + * + * Copyright 2022 Timesys Corp. + */ + +#include <linux/device.h> +#include <linux/kernel.h> +#include <linux/module.h> +#include <linux/mod_devicetable.h> +#include <linux/regmap.h> +#include <linux/regulator/consumer.h> +#include <linux/slab.h> +#include <linux/spi/spi.h> + +#include <linux/iio/iio.h> + +#define MAX5522_MAX_ADDR 15 +#define MAX5522_CTRL_NONE 0 +#define MAX5522_CTRL_LOAD_IN_A 9 +#define MAX5522_CTRL_LOAD_IN_B 10 + +#define MAX5522_REG_DATA(x) ((x) + MAX5522_CTRL_LOAD_IN_A) + +struct max5522_chip_info { + const char *name; + const struct iio_chan_spec *channels; + unsigned int num_channels; +}; + +struct max5522_state { + struct regmap *regmap; + const struct max5522_chip_info *chip_info; + unsigned short dac_cache[2]; + struct regulator *vrefin_reg; +}; + +#define MAX5522_CHANNEL(chan) { \ + .type = IIO_VOLTAGE, \ + .indexed = 1, \ + .output = 1, \ + .channel = chan, \ + .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | \ + BIT(IIO_CHAN_INFO_SCALE), \ + .scan_type = { \ + .sign = 'u', \ + .realbits = 10, \ + .storagebits = 16, \ + .shift = 2, \ + } \ +} + +static const struct iio_chan_spec max5522_channels[] = { + MAX5522_CHANNEL(0), + MAX5522_CHANNEL(1), +}; + +enum max5522_type { + ID_MAX5522, +}; + +static const struct max5522_chip_info max5522_chip_info_tbl[] = { + [ID_MAX5522] = { + .name = "max5522", + .channels = max5522_channels, + .num_channels = 2, + }, +}; + +static inline int max5522_info_to_reg(struct iio_chan_spec const *chan) +{ + return MAX5522_REG_DATA(chan->channel); +} + +static int max5522_read_raw(struct iio_dev *indio_dev, + struct iio_chan_spec const *chan, + int *val, int *val2, long info) +{ + struct max5522_state *state = iio_priv(indio_dev); + int ret; + + switch (info) { + case IIO_CHAN_INFO_RAW: + *val = state->dac_cache[chan->channel]; + return IIO_VAL_INT; + case IIO_CHAN_INFO_SCALE: + ret = regulator_get_voltage(state->vrefin_reg); + if (ret < 0) + return -EINVAL; + *val = ret / 1000; + *val2 = 10; + return IIO_VAL_FRACTIONAL_LOG2; + default: + return -EINVAL; + } + + return -EINVAL; +} + +static int max5522_write_raw(struct iio_dev *indio_dev, + struct iio_chan_spec const *chan, + int val, int val2, long info) +{ + struct max5522_state *state = iio_priv(indio_dev); + int rval; + + if (val > 1023 || val < 0) + return -EINVAL; + + rval = regmap_write(state->regmap, max5522_info_to_reg(chan), + val << chan->scan_type.shift); + if (rval < 0) + return rval; + + state->dac_cache[chan->channel] = val; + + return 0; +} + +static const struct iio_info max5522_info = { + .read_raw = max5522_read_raw, + .write_raw = max5522_write_raw, +}; + +static const struct regmap_config max5522_regmap_config = { + .reg_bits = 4, + .val_bits = 12, + .max_register = MAX5522_MAX_ADDR, +}; + +static int max5522_spi_probe(struct spi_device *spi) +{ + const struct spi_device_id *id = spi_get_device_id(spi); + struct iio_dev *indio_dev; + struct max5522_state *state; + int ret; + + indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*state)); + if (indio_dev == NULL) { + dev_err(&spi->dev, "failed to allocate iio device\n"); + return -ENOMEM; + } + + state = iio_priv(indio_dev); + state->chip_info = device_get_match_data(&spi->dev); + if (!state->chip_info) { + state->chip_info = + (struct max5522_chip_info *)(id->driver_data); + if (!state->chip_info) + return -EINVAL; + } + + state->vrefin_reg = devm_regulator_get(&spi->dev, "vrefin"); + if (IS_ERR(state->vrefin_reg)) + return dev_err_probe(&spi->dev, PTR_ERR(state->vrefin_reg), + "Vrefin regulator not specified\n"); + + ret = regulator_enable(state->vrefin_reg); + if (ret) { + return dev_err_probe(&spi->dev, ret, + "Failed to enable vref regulators\n"); + } + + state->regmap = devm_regmap_init_spi(spi, &max5522_regmap_config); + + if (IS_ERR(state->regmap)) + return PTR_ERR(state->regmap); + + indio_dev->info = &max5522_info; + indio_dev->modes = INDIO_DIRECT_MODE; + indio_dev->channels = max5522_channels; + indio_dev->num_channels = ARRAY_SIZE(max5522_channels); + indio_dev->name = max5522_chip_info_tbl[ID_MAX5522].name; + + return devm_iio_device_register(&spi->dev, indio_dev); +} + +static const struct spi_device_id max5522_ids[] = { + { "max5522", (kernel_ulong_t)&max5522_chip_info_tbl[ID_MAX5522] }, + {} +}; +MODULE_DEVICE_TABLE(spi, max5522_ids); + +static const struct of_device_id max5522_of_match[] = { + { + .compatible = "maxim,max5522", + .data = &max5522_chip_info_tbl[ID_MAX5522], + }, + {} +}; +MODULE_DEVICE_TABLE(of, max5522_of_match); + +static struct spi_driver max5522_spi_driver = { + .driver = { + .name = "max5522", + .of_match_table = max5522_of_match, + }, + .probe = max5522_spi_probe, + .id_table = max5522_ids, +}; +module_spi_driver(max5522_spi_driver); + +MODULE_AUTHOR("Angelo Dureghello <angelo.dureghello@timesys.com"); +MODULE_DESCRIPTION("MAX5522 DAC driver"); +MODULE_LICENSE("GPL"); |