// 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");