ad5504.c

  1// SPDX-License-Identifier: GPL-2.0-only
  2/*
  3 * AD5504, AD5501 High Voltage Digital to Analog Converter
  4 *
  5 * Copyright 2011 Analog Devices Inc.
  6 */
  7
  8#include <linux/interrupt.h>
  9#include <linux/fs.h>
 10#include <linux/device.h>
 11#include <linux/kernel.h>
 12#include <linux/spi/spi.h>
 13#include <linux/slab.h>
 14#include <linux/sysfs.h>
 15#include <linux/regulator/consumer.h>
 16#include <linux/module.h>
 17#include <linux/bitops.h>
 18
 19#include <linux/iio/iio.h>
 20#include <linux/iio/sysfs.h>
 21#include <linux/iio/events.h>
 22#include <linux/iio/dac/ad5504.h>
 23
 24#define AD5504_RES_MASK			GENMASK(11, 0)
 25#define AD5504_CMD_READ			BIT(15)
 26#define AD5504_CMD_WRITE		0
 27#define AD5504_ADDR(addr)		((addr) << 12)
 28
 29/* Registers */
 30#define AD5504_ADDR_NOOP		0
 31#define AD5504_ADDR_DAC(x)		((x) + 1)
 32#define AD5504_ADDR_ALL_DAC		5
 33#define AD5504_ADDR_CTRL		7
 34
 35/* Control Register */
 36#define AD5504_DAC_PWR(ch)		((ch) << 2)
 37#define AD5504_DAC_PWRDWN_MODE(mode)	((mode) << 6)
 38#define AD5504_DAC_PWRDN_20K		0
 39#define AD5504_DAC_PWRDN_3STATE		1
 40
 41/**
 42 * struct ad5504_state - driver instance specific data
 43 * @spi:			spi_device
 44 * @reg:		supply regulator
 45 * @vref_mv:		actual reference voltage used
 46 * @pwr_down_mask:	power down mask
 47 * @pwr_down_mode:	current power down mode
 48 * @data:		transfer buffer
 49 */
 50struct ad5504_state {
 51	struct spi_device		*spi;
 52	struct regulator		*reg;
 53	unsigned short			vref_mv;
 54	unsigned			pwr_down_mask;
 55	unsigned			pwr_down_mode;
 56
 57	__be16				data[2] __aligned(IIO_DMA_MINALIGN);
 58};
 59
 60/*
 61 * ad5504_supported_device_ids:
 62 */
 63enum ad5504_supported_device_ids {
 64	ID_AD5504,
 65	ID_AD5501,
 66};
 67
 68static int ad5504_spi_write(struct ad5504_state *st, u8 addr, u16 val)
 69{
 70	st->data[0] = cpu_to_be16(AD5504_CMD_WRITE | AD5504_ADDR(addr) |
 71			      (val & AD5504_RES_MASK));
 72
 73	return spi_write(st->spi, &st->data[0], 2);
 74}
 75
 76static int ad5504_spi_read(struct ad5504_state *st, u8 addr)
 77{
 78	int ret;
 79	struct spi_transfer t = {
 80	    .tx_buf = &st->data[0],
 81	    .rx_buf = &st->data[1],
 82	    .len = 2,
 83	};
 84
 85	st->data[0] = cpu_to_be16(AD5504_CMD_READ | AD5504_ADDR(addr));
 86	ret = spi_sync_transfer(st->spi, &t, 1);
 87	if (ret < 0)
 88		return ret;
 89
 90	return be16_to_cpu(st->data[1]) & AD5504_RES_MASK;
 91}
 92
 93static int ad5504_read_raw(struct iio_dev *indio_dev,
 94			   struct iio_chan_spec const *chan,
 95			   int *val,
 96			   int *val2,
 97			   long m)
 98{
 99	struct ad5504_state *st = iio_priv(indio_dev);
100	int ret;
101
102	switch (m) {
103	case IIO_CHAN_INFO_RAW:
104		ret = ad5504_spi_read(st, chan->address);
105		if (ret < 0)
106			return ret;
107
108		*val = ret;
109
110		return IIO_VAL_INT;
111	case IIO_CHAN_INFO_SCALE:
112		*val = st->vref_mv;
113		*val2 = chan->scan_type.realbits;
114		return IIO_VAL_FRACTIONAL_LOG2;
115	}
116	return -EINVAL;
117}
118
119static int ad5504_write_raw(struct iio_dev *indio_dev,
120			       struct iio_chan_spec const *chan,
121			       int val,
122			       int val2,
123			       long mask)
124{
125	struct ad5504_state *st = iio_priv(indio_dev);
126
127	switch (mask) {
128	case IIO_CHAN_INFO_RAW:
129		if (val >= (1 << chan->scan_type.realbits) || val < 0)
130			return -EINVAL;
131
132		return ad5504_spi_write(st, chan->address, val);
133	default:
134		return -EINVAL;
135	}
136}
137
138static const char * const ad5504_powerdown_modes[] = {
139	"20kohm_to_gnd",
140	"three_state",
141};
142
143static int ad5504_get_powerdown_mode(struct iio_dev *indio_dev,
144	const struct iio_chan_spec *chan)
145{
146	struct ad5504_state *st = iio_priv(indio_dev);
147
148	return st->pwr_down_mode;
149}
150
151static int ad5504_set_powerdown_mode(struct iio_dev *indio_dev,
152	const struct iio_chan_spec *chan, unsigned int mode)
153{
154	struct ad5504_state *st = iio_priv(indio_dev);
155
156	st->pwr_down_mode = mode;
157
158	return 0;
159}
160
161static const struct iio_enum ad5504_powerdown_mode_enum = {
162	.items = ad5504_powerdown_modes,
163	.num_items = ARRAY_SIZE(ad5504_powerdown_modes),
164	.get = ad5504_get_powerdown_mode,
165	.set = ad5504_set_powerdown_mode,
166};
167
168static ssize_t ad5504_read_dac_powerdown(struct iio_dev *indio_dev,
169	uintptr_t private, const struct iio_chan_spec *chan, char *buf)
170{
171	struct ad5504_state *st = iio_priv(indio_dev);
172
173	return sysfs_emit(buf, "%d\n",
174			  !(st->pwr_down_mask & (1 << chan->channel)));
175}
176
177static ssize_t ad5504_write_dac_powerdown(struct iio_dev *indio_dev,
178	uintptr_t private, const struct iio_chan_spec *chan, const char *buf,
179	size_t len)
180{
181	bool pwr_down;
182	int ret;
183	struct ad5504_state *st = iio_priv(indio_dev);
184
185	ret = kstrtobool(buf, &pwr_down);
186	if (ret)
187		return ret;
188
189	if (pwr_down)
190		st->pwr_down_mask &= ~(1 << chan->channel);
191	else
192		st->pwr_down_mask |= (1 << chan->channel);
193
194	ret = ad5504_spi_write(st, AD5504_ADDR_CTRL,
195				AD5504_DAC_PWRDWN_MODE(st->pwr_down_mode) |
196				AD5504_DAC_PWR(st->pwr_down_mask));
197
198	/* writes to the CTRL register must be followed by a NOOP */
199	ad5504_spi_write(st, AD5504_ADDR_NOOP, 0);
200
201	return ret ? ret : len;
202}
203
204static IIO_CONST_ATTR(temp0_thresh_rising_value, "110000");
205static IIO_CONST_ATTR(temp0_thresh_rising_en, "1");
206
207static struct attribute *ad5504_ev_attributes[] = {
208	&iio_const_attr_temp0_thresh_rising_value.dev_attr.attr,
209	&iio_const_attr_temp0_thresh_rising_en.dev_attr.attr,
210	NULL,
211};
212
213static const struct attribute_group ad5504_ev_attribute_group = {
214	.attrs = ad5504_ev_attributes,
215};
216
217static irqreturn_t ad5504_event_handler(int irq, void *private)
218{
219	iio_push_event(private,
220		       IIO_UNMOD_EVENT_CODE(IIO_TEMP,
221					    0,
222					    IIO_EV_TYPE_THRESH,
223					    IIO_EV_DIR_RISING),
224		       iio_get_time_ns(private));
225
226	return IRQ_HANDLED;
227}
228
229static const struct iio_info ad5504_info = {
230	.write_raw = ad5504_write_raw,
231	.read_raw = ad5504_read_raw,
232	.event_attrs = &ad5504_ev_attribute_group,
233};
234
235static const struct iio_chan_spec_ext_info ad5504_ext_info[] = {
236	{
237		.name = "powerdown",
238		.read = ad5504_read_dac_powerdown,
239		.write = ad5504_write_dac_powerdown,
240		.shared = IIO_SEPARATE,
241	},
242	IIO_ENUM("powerdown_mode", IIO_SHARED_BY_TYPE,
243		 &ad5504_powerdown_mode_enum),
244	IIO_ENUM_AVAILABLE("powerdown_mode", IIO_SHARED_BY_TYPE, &ad5504_powerdown_mode_enum),
245	{ }
246};
247
248#define AD5504_CHANNEL(_chan) { \
249	.type = IIO_VOLTAGE, \
250	.indexed = 1, \
251	.output = 1, \
252	.channel = (_chan), \
253	.info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \
254	.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE), \
255	.address = AD5504_ADDR_DAC(_chan), \
256	.scan_type = { \
257		.sign = 'u', \
258		.realbits = 12, \
259		.storagebits = 16, \
260	}, \
261	.ext_info = ad5504_ext_info, \
262}
263
264static const struct iio_chan_spec ad5504_channels[] = {
265	AD5504_CHANNEL(0),
266	AD5504_CHANNEL(1),
267	AD5504_CHANNEL(2),
268	AD5504_CHANNEL(3),
269};
270
271static int ad5504_probe(struct spi_device *spi)
272{
273	const struct ad5504_platform_data *pdata = dev_get_platdata(&spi->dev);
274	struct iio_dev *indio_dev;
275	struct ad5504_state *st;
276	int ret;
277
278	indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*st));
279	if (!indio_dev)
280		return -ENOMEM;
281
282	st = iio_priv(indio_dev);
283
284	ret = devm_regulator_get_enable_read_voltage(&spi->dev, "vcc");
285	if (ret < 0 && ret != -ENODEV)
286		return ret;
287	if (ret == -ENODEV) {
288		if (pdata->vref_mv)
289			st->vref_mv = pdata->vref_mv;
290		else
291			dev_warn(&spi->dev, "reference voltage unspecified\n");
292	} else {
293		st->vref_mv = ret / 1000;
294	}
295
296	st->spi = spi;
297	indio_dev->name = spi_get_device_id(st->spi)->name;
298	indio_dev->info = &ad5504_info;
299	if (spi_get_device_id(st->spi)->driver_data == ID_AD5501)
300		indio_dev->num_channels = 1;
301	else
302		indio_dev->num_channels = 4;
303	indio_dev->channels = ad5504_channels;
304	indio_dev->modes = INDIO_DIRECT_MODE;
305
306	if (spi->irq) {
307		ret = devm_request_threaded_irq(&spi->dev, spi->irq,
308					   NULL,
309					   &ad5504_event_handler,
310					   IRQF_TRIGGER_FALLING | IRQF_ONESHOT,
311					   spi_get_device_id(st->spi)->name,
312					   indio_dev);
313		if (ret)
314			return ret;
315	}
316
317	return devm_iio_device_register(&spi->dev, indio_dev);
318}
319
320static const struct spi_device_id ad5504_id[] = {
321	{"ad5504", ID_AD5504},
322	{"ad5501", ID_AD5501},
323	{ }
324};
325MODULE_DEVICE_TABLE(spi, ad5504_id);
326
327static struct spi_driver ad5504_driver = {
328	.driver = {
329		   .name = "ad5504",
330		   },
331	.probe = ad5504_probe,
332	.id_table = ad5504_id,
333};
334module_spi_driver(ad5504_driver);
335
336MODULE_AUTHOR("Michael Hennerich <michael.hennerich@analog.com>");
337MODULE_DESCRIPTION("Analog Devices AD5501/AD5501 DAC");
338MODULE_LICENSE("GPL v2");