ad5449.c

  1// SPDX-License-Identifier: GPL-2.0-only
  2/*
  3 * AD5415, AD5426, AD5429, AD5432, AD5439, AD5443, AD5449 Digital to Analog
  4 * Converter driver.
  5 *
  6 * Copyright 2012 Analog Devices Inc.
  7 *  Author: Lars-Peter Clausen <lars@metafoo.de>
  8 */
  9
 10#include <linux/device.h>
 11#include <linux/err.h>
 12#include <linux/module.h>
 13#include <linux/kernel.h>
 14#include <linux/spi/spi.h>
 15#include <linux/slab.h>
 16#include <linux/sysfs.h>
 17#include <linux/regulator/consumer.h>
 18#include <linux/unaligned.h>
 19
 20#include <linux/iio/iio.h>
 21#include <linux/iio/sysfs.h>
 22
 23#define AD5449_MAX_CHANNELS		2
 24#define AD5449_MAX_VREFS		2
 25
 26#define AD5449_CMD_NOOP			0x0
 27#define AD5449_CMD_LOAD_AND_UPDATE(x)	(0x1 + (x) * 3)
 28#define AD5449_CMD_READ(x)		(0x2 + (x) * 3)
 29#define AD5449_CMD_LOAD(x)		(0x3 + (x) * 3)
 30#define AD5449_CMD_CTRL			13
 31
 32#define AD5449_CTRL_SDO_OFFSET		10
 33#define AD5449_CTRL_DAISY_CHAIN		BIT(9)
 34#define AD5449_CTRL_HCLR_TO_MIDSCALE	BIT(8)
 35#define AD5449_CTRL_SAMPLE_RISING	BIT(7)
 36
 37/**
 38 * struct ad5449_chip_info - chip specific information
 39 * @channels:		Channel specification
 40 * @num_channels:	Number of channels
 41 * @has_ctrl:		Chip has a control register
 42 */
 43struct ad5449_chip_info {
 44	const struct iio_chan_spec *channels;
 45	unsigned int num_channels;
 46	bool has_ctrl;
 47};
 48
 49/**
 50 * struct ad5449 - driver instance specific data
 51 * @spi:		the SPI device for this driver instance
 52 * @chip_info:		chip model specific constants, available modes etc
 53 * @vref_reg:		vref supply regulators
 54 * @has_sdo:		whether the SDO line is connected
 55 * @dac_cache:		Cache for the DAC values
 56 * @data:		spi transfer buffers
 57 * @lock:		lock to protect the data buffer during SPI ops
 58 */
 59struct ad5449 {
 60	struct spi_device		*spi;
 61	const struct ad5449_chip_info	*chip_info;
 62	struct regulator_bulk_data	vref_reg[AD5449_MAX_VREFS];
 63	struct mutex			lock;
 64
 65	bool has_sdo;
 66	uint16_t dac_cache[AD5449_MAX_CHANNELS];
 67
 68	/*
 69	 * DMA (thus cache coherency maintenance) may require the
 70	 * transfer buffers to live in their own cache lines.
 71	 */
 72	__be16 data[2] __aligned(IIO_DMA_MINALIGN);
 73};
 74
 75enum ad5449_type {
 76	ID_AD5426,
 77	ID_AD5429,
 78	ID_AD5432,
 79	ID_AD5439,
 80	ID_AD5443,
 81	ID_AD5449,
 82};
 83
 84static int ad5449_write(struct iio_dev *indio_dev, unsigned int addr,
 85	unsigned int val)
 86{
 87	struct ad5449 *st = iio_priv(indio_dev);
 88	int ret;
 89
 90	mutex_lock(&st->lock);
 91	st->data[0] = cpu_to_be16((addr << 12) | val);
 92	ret = spi_write(st->spi, st->data, 2);
 93	mutex_unlock(&st->lock);
 94
 95	return ret;
 96}
 97
 98static int ad5449_read(struct iio_dev *indio_dev, unsigned int addr,
 99	unsigned int *val)
100{
101	struct ad5449 *st = iio_priv(indio_dev);
102	int ret;
103	struct spi_transfer t[] = {
104		{
105			.tx_buf = &st->data[0],
106			.len = 2,
107			.cs_change = 1,
108		}, {
109			.tx_buf = &st->data[1],
110			.rx_buf = &st->data[1],
111			.len = 2,
112		},
113	};
114
115	mutex_lock(&st->lock);
116	st->data[0] = cpu_to_be16(addr << 12);
117	st->data[1] = cpu_to_be16(AD5449_CMD_NOOP);
118
119	ret = spi_sync_transfer(st->spi, t, ARRAY_SIZE(t));
120	if (ret < 0)
121		goto out_unlock;
122
123	*val = be16_to_cpu(st->data[1]);
124
125out_unlock:
126	mutex_unlock(&st->lock);
127	return ret;
128}
129
130static int ad5449_read_raw(struct iio_dev *indio_dev,
131	struct iio_chan_spec const *chan, int *val, int *val2, long info)
132{
133	struct ad5449 *st = iio_priv(indio_dev);
134	struct regulator_bulk_data *reg;
135	int scale_uv;
136	int ret;
137
138	switch (info) {
139	case IIO_CHAN_INFO_RAW:
140		if (st->has_sdo) {
141			ret = ad5449_read(indio_dev,
142				AD5449_CMD_READ(chan->address), val);
143			if (ret)
144				return ret;
145			*val &= 0xfff;
146		} else {
147			*val = st->dac_cache[chan->address];
148		}
149
150		return IIO_VAL_INT;
151	case IIO_CHAN_INFO_SCALE:
152		reg = &st->vref_reg[chan->channel];
153		scale_uv = regulator_get_voltage(reg->consumer);
154		if (scale_uv < 0)
155			return scale_uv;
156
157		*val = scale_uv / 1000;
158		*val2 = chan->scan_type.realbits;
159
160		return IIO_VAL_FRACTIONAL_LOG2;
161	default:
162		break;
163	}
164
165	return -EINVAL;
166}
167
168static int ad5449_write_raw(struct iio_dev *indio_dev,
169	struct iio_chan_spec const *chan, int val, int val2, long info)
170{
171	struct ad5449 *st = iio_priv(indio_dev);
172	int ret;
173
174	switch (info) {
175	case IIO_CHAN_INFO_RAW:
176		if (val < 0 || val >= (1 << chan->scan_type.realbits))
177			return -EINVAL;
178
179		ret = ad5449_write(indio_dev,
180			AD5449_CMD_LOAD_AND_UPDATE(chan->address),
181			val << chan->scan_type.shift);
182		if (ret == 0)
183			st->dac_cache[chan->address] = val;
184		break;
185	default:
186		ret = -EINVAL;
187	}
188
189	return ret;
190}
191
192static const struct iio_info ad5449_info = {
193	.read_raw = ad5449_read_raw,
194	.write_raw = ad5449_write_raw,
195};
196
197#define AD5449_CHANNEL(chan, bits) {				\
198	.type = IIO_VOLTAGE,					\
199	.indexed = 1,						\
200	.output = 1,						\
201	.channel = (chan),					\
202	.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |		\
203		BIT(IIO_CHAN_INFO_SCALE),			\
204	.address = (chan),					\
205	.scan_type = {						\
206		.sign = 'u',					\
207		.realbits = (bits),				\
208		.storagebits = 16,				\
209		.shift = 12 - (bits),				\
210	},							\
211}
212
213#define DECLARE_AD5449_CHANNELS(name, bits) \
214const struct iio_chan_spec name[] = { \
215	AD5449_CHANNEL(0, bits), \
216	AD5449_CHANNEL(1, bits), \
217}
218
219static DECLARE_AD5449_CHANNELS(ad5429_channels, 8);
220static DECLARE_AD5449_CHANNELS(ad5439_channels, 10);
221static DECLARE_AD5449_CHANNELS(ad5449_channels, 12);
222
223static const struct ad5449_chip_info ad5449_chip_info[] = {
224	[ID_AD5426] = {
225		.channels = ad5429_channels,
226		.num_channels = 1,
227		.has_ctrl = false,
228	},
229	[ID_AD5429] = {
230		.channels = ad5429_channels,
231		.num_channels = 2,
232		.has_ctrl = true,
233	},
234	[ID_AD5432] = {
235		.channels = ad5439_channels,
236		.num_channels = 1,
237		.has_ctrl = false,
238	},
239	[ID_AD5439] = {
240		.channels = ad5439_channels,
241		.num_channels = 2,
242		.has_ctrl = true,
243	},
244	[ID_AD5443] = {
245		.channels = ad5449_channels,
246		.num_channels = 1,
247		.has_ctrl = false,
248	},
249	[ID_AD5449] = {
250		.channels = ad5449_channels,
251		.num_channels = 2,
252		.has_ctrl = true,
253	},
254};
255
256static const char *ad5449_vref_name(struct ad5449 *st, int n)
257{
258	if (st->chip_info->num_channels == 1)
259		return "VREF";
260
261	if (n == 0)
262		return "VREFA";
263	else
264		return "VREFB";
265}
266
267static int ad5449_spi_probe(struct spi_device *spi)
268{
269	const struct spi_device_id *id = spi_get_device_id(spi);
270	struct iio_dev *indio_dev;
271	struct ad5449 *st;
272	unsigned int i;
273	int ret;
274
275	indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*st));
276	if (indio_dev == NULL)
277		return -ENOMEM;
278
279	st = iio_priv(indio_dev);
280	spi_set_drvdata(spi, indio_dev);
281
282	st->chip_info = &ad5449_chip_info[id->driver_data];
283	st->spi = spi;
284
285	for (i = 0; i < st->chip_info->num_channels; ++i)
286		st->vref_reg[i].supply = ad5449_vref_name(st, i);
287
288	ret = devm_regulator_bulk_get(&spi->dev, st->chip_info->num_channels,
289				st->vref_reg);
290	if (ret)
291		return ret;
292
293	ret = regulator_bulk_enable(st->chip_info->num_channels, st->vref_reg);
294	if (ret)
295		return ret;
296
297	indio_dev->name = id->name;
298	indio_dev->info = &ad5449_info;
299	indio_dev->modes = INDIO_DIRECT_MODE;
300	indio_dev->channels = st->chip_info->channels;
301	indio_dev->num_channels = st->chip_info->num_channels;
302
303	mutex_init(&st->lock);
304
305	if (st->chip_info->has_ctrl) {
306		st->has_sdo = true;
307		ad5449_write(indio_dev, AD5449_CMD_CTRL, 0x0);
308	}
309
310	ret = iio_device_register(indio_dev);
311	if (ret)
312		goto error_disable_reg;
313
314	return 0;
315
316error_disable_reg:
317	regulator_bulk_disable(st->chip_info->num_channels, st->vref_reg);
318
319	return ret;
320}
321
322static void ad5449_spi_remove(struct spi_device *spi)
323{
324	struct iio_dev *indio_dev = spi_get_drvdata(spi);
325	struct ad5449 *st = iio_priv(indio_dev);
326
327	iio_device_unregister(indio_dev);
328
329	regulator_bulk_disable(st->chip_info->num_channels, st->vref_reg);
330}
331
332static const struct spi_device_id ad5449_spi_ids[] = {
333	{ "ad5415", ID_AD5449 },
334	{ "ad5426", ID_AD5426 },
335	{ "ad5429", ID_AD5429 },
336	{ "ad5432", ID_AD5432 },
337	{ "ad5439", ID_AD5439 },
338	{ "ad5443", ID_AD5443 },
339	{ "ad5449", ID_AD5449 },
340	{ }
341};
342MODULE_DEVICE_TABLE(spi, ad5449_spi_ids);
343
344static struct spi_driver ad5449_spi_driver = {
345	.driver = {
346		.name = "ad5449",
347	},
348	.probe = ad5449_spi_probe,
349	.remove = ad5449_spi_remove,
350	.id_table = ad5449_spi_ids,
351};
352module_spi_driver(ad5449_spi_driver);
353
354MODULE_AUTHOR("Lars-Peter Clausen <lars@metafoo.de>");
355MODULE_DESCRIPTION("Analog Devices AD5449 and similar DACs");
356MODULE_LICENSE("GPL v2");