diff options
Diffstat (limited to 'drivers/iio/dac/ad5449.c')
| -rw-r--r-- | drivers/iio/dac/ad5449.c | 367 |
1 files changed, 367 insertions, 0 deletions
diff --git a/drivers/iio/dac/ad5449.c b/drivers/iio/dac/ad5449.c new file mode 100644 index 000000000..4572d6f49 --- /dev/null +++ b/drivers/iio/dac/ad5449.c @@ -0,0 +1,367 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * AD5415, AD5426, AD5429, AD5432, AD5439, AD5443, AD5449 Digital to Analog + * Converter driver. + * + * Copyright 2012 Analog Devices Inc. + * Author: Lars-Peter Clausen <lars@metafoo.de> + */ + +#include <linux/device.h> +#include <linux/err.h> +#include <linux/module.h> +#include <linux/kernel.h> +#include <linux/spi/spi.h> +#include <linux/slab.h> +#include <linux/sysfs.h> +#include <linux/regulator/consumer.h> +#include <asm/unaligned.h> + +#include <linux/iio/iio.h> +#include <linux/iio/sysfs.h> + +#include <linux/platform_data/ad5449.h> + +#define AD5449_MAX_CHANNELS 2 +#define AD5449_MAX_VREFS 2 + +#define AD5449_CMD_NOOP 0x0 +#define AD5449_CMD_LOAD_AND_UPDATE(x) (0x1 + (x) * 3) +#define AD5449_CMD_READ(x) (0x2 + (x) * 3) +#define AD5449_CMD_LOAD(x) (0x3 + (x) * 3) +#define AD5449_CMD_CTRL 13 + +#define AD5449_CTRL_SDO_OFFSET 10 +#define AD5449_CTRL_DAISY_CHAIN BIT(9) +#define AD5449_CTRL_HCLR_TO_MIDSCALE BIT(8) +#define AD5449_CTRL_SAMPLE_RISING BIT(7) + +/** + * struct ad5449_chip_info - chip specific information + * @channels: Channel specification + * @num_channels: Number of channels + * @has_ctrl: Chip has a control register + */ +struct ad5449_chip_info { + const struct iio_chan_spec *channels; + unsigned int num_channels; + bool has_ctrl; +}; + +/** + * struct ad5449 - driver instance specific data + * @spi: the SPI device for this driver instance + * @chip_info: chip model specific constants, available modes etc + * @vref_reg: vref supply regulators + * @has_sdo: whether the SDO line is connected + * @dac_cache: Cache for the DAC values + * @data: spi transfer buffers + * @lock: lock to protect the data buffer during SPI ops + */ +struct ad5449 { + struct spi_device *spi; + const struct ad5449_chip_info *chip_info; + struct regulator_bulk_data vref_reg[AD5449_MAX_VREFS]; + struct mutex lock; + + bool has_sdo; + uint16_t dac_cache[AD5449_MAX_CHANNELS]; + + /* + * DMA (thus cache coherency maintenance) may require the + * transfer buffers to live in their own cache lines. + */ + __be16 data[2] __aligned(IIO_DMA_MINALIGN); +}; + +enum ad5449_type { + ID_AD5426, + ID_AD5429, + ID_AD5432, + ID_AD5439, + ID_AD5443, + ID_AD5449, +}; + +static int ad5449_write(struct iio_dev *indio_dev, unsigned int addr, + unsigned int val) +{ + struct ad5449 *st = iio_priv(indio_dev); + int ret; + + mutex_lock(&st->lock); + st->data[0] = cpu_to_be16((addr << 12) | val); + ret = spi_write(st->spi, st->data, 2); + mutex_unlock(&st->lock); + + return ret; +} + +static int ad5449_read(struct iio_dev *indio_dev, unsigned int addr, + unsigned int *val) +{ + struct ad5449 *st = iio_priv(indio_dev); + int ret; + struct spi_transfer t[] = { + { + .tx_buf = &st->data[0], + .len = 2, + .cs_change = 1, + }, { + .tx_buf = &st->data[1], + .rx_buf = &st->data[1], + .len = 2, + }, + }; + + mutex_lock(&st->lock); + st->data[0] = cpu_to_be16(addr << 12); + st->data[1] = cpu_to_be16(AD5449_CMD_NOOP); + + ret = spi_sync_transfer(st->spi, t, ARRAY_SIZE(t)); + if (ret < 0) + goto out_unlock; + + *val = be16_to_cpu(st->data[1]); + +out_unlock: + mutex_unlock(&st->lock); + return ret; +} + +static int ad5449_read_raw(struct iio_dev *indio_dev, + struct iio_chan_spec const *chan, int *val, int *val2, long info) +{ + struct ad5449 *st = iio_priv(indio_dev); + struct regulator_bulk_data *reg; + int scale_uv; + int ret; + + switch (info) { + case IIO_CHAN_INFO_RAW: + if (st->has_sdo) { + ret = ad5449_read(indio_dev, + AD5449_CMD_READ(chan->address), val); + if (ret) + return ret; + *val &= 0xfff; + } else { + *val = st->dac_cache[chan->address]; + } + + return IIO_VAL_INT; + case IIO_CHAN_INFO_SCALE: + reg = &st->vref_reg[chan->channel]; + scale_uv = regulator_get_voltage(reg->consumer); + if (scale_uv < 0) + return scale_uv; + + *val = scale_uv / 1000; + *val2 = chan->scan_type.realbits; + + return IIO_VAL_FRACTIONAL_LOG2; + default: + break; + } + + return -EINVAL; +} + +static int ad5449_write_raw(struct iio_dev *indio_dev, + struct iio_chan_spec const *chan, int val, int val2, long info) +{ + struct ad5449 *st = iio_priv(indio_dev); + int ret; + + switch (info) { + case IIO_CHAN_INFO_RAW: + if (val < 0 || val >= (1 << chan->scan_type.realbits)) + return -EINVAL; + + ret = ad5449_write(indio_dev, + AD5449_CMD_LOAD_AND_UPDATE(chan->address), + val << chan->scan_type.shift); + if (ret == 0) + st->dac_cache[chan->address] = val; + break; + default: + ret = -EINVAL; + } + + return ret; +} + +static const struct iio_info ad5449_info = { + .read_raw = ad5449_read_raw, + .write_raw = ad5449_write_raw, +}; + +#define AD5449_CHANNEL(chan, bits) { \ + .type = IIO_VOLTAGE, \ + .indexed = 1, \ + .output = 1, \ + .channel = (chan), \ + .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | \ + BIT(IIO_CHAN_INFO_SCALE), \ + .address = (chan), \ + .scan_type = { \ + .sign = 'u', \ + .realbits = (bits), \ + .storagebits = 16, \ + .shift = 12 - (bits), \ + }, \ +} + +#define DECLARE_AD5449_CHANNELS(name, bits) \ +const struct iio_chan_spec name[] = { \ + AD5449_CHANNEL(0, bits), \ + AD5449_CHANNEL(1, bits), \ +} + +static DECLARE_AD5449_CHANNELS(ad5429_channels, 8); +static DECLARE_AD5449_CHANNELS(ad5439_channels, 10); +static DECLARE_AD5449_CHANNELS(ad5449_channels, 12); + +static const struct ad5449_chip_info ad5449_chip_info[] = { + [ID_AD5426] = { + .channels = ad5429_channels, + .num_channels = 1, + .has_ctrl = false, + }, + [ID_AD5429] = { + .channels = ad5429_channels, + .num_channels = 2, + .has_ctrl = true, + }, + [ID_AD5432] = { + .channels = ad5439_channels, + .num_channels = 1, + .has_ctrl = false, + }, + [ID_AD5439] = { + .channels = ad5439_channels, + .num_channels = 2, + .has_ctrl = true, + }, + [ID_AD5443] = { + .channels = ad5449_channels, + .num_channels = 1, + .has_ctrl = false, + }, + [ID_AD5449] = { + .channels = ad5449_channels, + .num_channels = 2, + .has_ctrl = true, + }, +}; + +static const char *ad5449_vref_name(struct ad5449 *st, int n) +{ + if (st->chip_info->num_channels == 1) + return "VREF"; + + if (n == 0) + return "VREFA"; + else + return "VREFB"; +} + +static int ad5449_spi_probe(struct spi_device *spi) +{ + struct ad5449_platform_data *pdata = spi->dev.platform_data; + const struct spi_device_id *id = spi_get_device_id(spi); + struct iio_dev *indio_dev; + struct ad5449 *st; + unsigned int i; + int ret; + + indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*st)); + if (indio_dev == NULL) + return -ENOMEM; + + st = iio_priv(indio_dev); + spi_set_drvdata(spi, indio_dev); + + st->chip_info = &ad5449_chip_info[id->driver_data]; + st->spi = spi; + + for (i = 0; i < st->chip_info->num_channels; ++i) + st->vref_reg[i].supply = ad5449_vref_name(st, i); + + ret = devm_regulator_bulk_get(&spi->dev, st->chip_info->num_channels, + st->vref_reg); + if (ret) + return ret; + + ret = regulator_bulk_enable(st->chip_info->num_channels, st->vref_reg); + if (ret) + return ret; + + indio_dev->name = id->name; + indio_dev->info = &ad5449_info; + indio_dev->modes = INDIO_DIRECT_MODE; + indio_dev->channels = st->chip_info->channels; + indio_dev->num_channels = st->chip_info->num_channels; + + mutex_init(&st->lock); + + if (st->chip_info->has_ctrl) { + unsigned int ctrl = 0x00; + if (pdata) { + if (pdata->hardware_clear_to_midscale) + ctrl |= AD5449_CTRL_HCLR_TO_MIDSCALE; + ctrl |= pdata->sdo_mode << AD5449_CTRL_SDO_OFFSET; + st->has_sdo = pdata->sdo_mode != AD5449_SDO_DISABLED; + } else { + st->has_sdo = true; + } + ad5449_write(indio_dev, AD5449_CMD_CTRL, ctrl); + } + + ret = iio_device_register(indio_dev); + if (ret) + goto error_disable_reg; + + return 0; + +error_disable_reg: + regulator_bulk_disable(st->chip_info->num_channels, st->vref_reg); + + return ret; +} + +static void ad5449_spi_remove(struct spi_device *spi) +{ + struct iio_dev *indio_dev = spi_get_drvdata(spi); + struct ad5449 *st = iio_priv(indio_dev); + + iio_device_unregister(indio_dev); + + regulator_bulk_disable(st->chip_info->num_channels, st->vref_reg); +} + +static const struct spi_device_id ad5449_spi_ids[] = { + { "ad5415", ID_AD5449 }, + { "ad5426", ID_AD5426 }, + { "ad5429", ID_AD5429 }, + { "ad5432", ID_AD5432 }, + { "ad5439", ID_AD5439 }, + { "ad5443", ID_AD5443 }, + { "ad5449", ID_AD5449 }, + {} +}; +MODULE_DEVICE_TABLE(spi, ad5449_spi_ids); + +static struct spi_driver ad5449_spi_driver = { + .driver = { + .name = "ad5449", + }, + .probe = ad5449_spi_probe, + .remove = ad5449_spi_remove, + .id_table = ad5449_spi_ids, +}; +module_spi_driver(ad5449_spi_driver); + +MODULE_AUTHOR("Lars-Peter Clausen <lars@metafoo.de>"); +MODULE_DESCRIPTION("Analog Devices AD5449 and similar DACs"); +MODULE_LICENSE("GPL v2"); |