|  | /* | 
|  | * AD5415, AD5426, AD5429, AD5432, AD5439, AD5443, AD5449 Digital to Analog | 
|  | * Converter driver. | 
|  | * | 
|  | * Copyright 2012 Analog Devices Inc. | 
|  | *  Author: Lars-Peter Clausen <lars@metafoo.de> | 
|  | * | 
|  | * Licensed under the GPL-2. | 
|  | */ | 
|  |  | 
|  | #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 | 
|  | */ | 
|  | struct ad5449 { | 
|  | struct spi_device		*spi; | 
|  | const struct ad5449_chip_info	*chip_info; | 
|  | struct regulator_bulk_data	vref_reg[AD5449_MAX_VREFS]; | 
|  |  | 
|  | bool has_sdo; | 
|  | uint16_t dac_cache[AD5449_MAX_CHANNELS]; | 
|  |  | 
|  | /* | 
|  | * DMA (thus cache coherency maintenance) requires the | 
|  | * transfer buffers to live in their own cache lines. | 
|  | */ | 
|  | __be16 data[2] ____cacheline_aligned; | 
|  | }; | 
|  |  | 
|  | 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(&indio_dev->mlock); | 
|  | st->data[0] = cpu_to_be16((addr << 12) | val); | 
|  | ret = spi_write(st->spi, st->data, 2); | 
|  | mutex_unlock(&indio_dev->mlock); | 
|  |  | 
|  | 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(&indio_dev->mlock); | 
|  | 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(&indio_dev->mlock); | 
|  | 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->dev.parent = &spi->dev; | 
|  | 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; | 
|  |  | 
|  | 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 int 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); | 
|  |  | 
|  | return 0; | 
|  | } | 
|  |  | 
|  | 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"); |