ad5446.c

  1// SPDX-License-Identifier: GPL-2.0-or-later
  2/*
  3 * AD5446 CORE DAC driver
  4 *
  5 * Copyright 2010 Analog Devices Inc.
  6 */
  7
  8#include <linux/array_size.h>
  9#include <linux/cleanup.h>
 10#include <linux/device.h>
 11#include <linux/err.h>
 12#include <linux/export.h>
 13#include <linux/iio/iio.h>
 14#include <linux/kstrtox.h>
 15#include <linux/module.h>
 16#include <linux/mutex.h>
 17#include <linux/regulator/consumer.h>
 18#include <linux/sysfs.h>
 19
 20#include "ad5446.h"
 21
 22#define MODE_PWRDWN_1k		0x1
 23#define MODE_PWRDWN_100k	0x2
 24#define MODE_PWRDWN_TRISTATE	0x3
 25
 26static const char * const ad5446_powerdown_modes[] = {
 27	"1kohm_to_gnd", "100kohm_to_gnd", "three_state"
 28};
 29
 30static int ad5446_set_powerdown_mode(struct iio_dev *indio_dev,
 31				     const struct iio_chan_spec *chan,
 32				     unsigned int mode)
 33{
 34	struct ad5446_state *st = iio_priv(indio_dev);
 35
 36	st->pwr_down_mode = mode + 1;
 37
 38	return 0;
 39}
 40
 41static int ad5446_get_powerdown_mode(struct iio_dev *indio_dev,
 42				     const struct iio_chan_spec *chan)
 43{
 44	struct ad5446_state *st = iio_priv(indio_dev);
 45
 46	return st->pwr_down_mode - 1;
 47}
 48
 49static const struct iio_enum ad5446_powerdown_mode_enum = {
 50	.items = ad5446_powerdown_modes,
 51	.num_items = ARRAY_SIZE(ad5446_powerdown_modes),
 52	.get = ad5446_get_powerdown_mode,
 53	.set = ad5446_set_powerdown_mode,
 54};
 55
 56static ssize_t ad5446_read_dac_powerdown(struct iio_dev *indio_dev,
 57					 uintptr_t private,
 58					 const struct iio_chan_spec *chan,
 59					 char *buf)
 60{
 61	struct ad5446_state *st = iio_priv(indio_dev);
 62
 63	return sysfs_emit(buf, "%d\n", st->pwr_down);
 64}
 65
 66static ssize_t ad5446_write_dac_powerdown(struct iio_dev *indio_dev,
 67					  uintptr_t private,
 68					  const struct iio_chan_spec *chan,
 69					  const char *buf, size_t len)
 70{
 71	struct ad5446_state *st = iio_priv(indio_dev);
 72	unsigned int shift;
 73	unsigned int val;
 74	bool powerdown;
 75	int ret;
 76
 77	ret = kstrtobool(buf, &powerdown);
 78	if (ret)
 79		return ret;
 80
 81	guard(mutex)(&st->lock);
 82	st->pwr_down = powerdown;
 83
 84	if (st->pwr_down) {
 85		shift = chan->scan_type.realbits + chan->scan_type.shift;
 86		val = st->pwr_down_mode << shift;
 87	} else {
 88		val = st->cached_val;
 89	}
 90
 91	ret = st->chip_info->write(st, val);
 92	if (ret)
 93		return ret;
 94
 95	return len;
 96}
 97
 98const struct iio_chan_spec_ext_info ad5446_ext_info_powerdown[] = {
 99	{
100		.name = "powerdown",
101		.read = ad5446_read_dac_powerdown,
102		.write = ad5446_write_dac_powerdown,
103		.shared = IIO_SEPARATE,
104	},
105	IIO_ENUM("powerdown_mode", IIO_SEPARATE, &ad5446_powerdown_mode_enum),
106	IIO_ENUM_AVAILABLE("powerdown_mode", IIO_SHARED_BY_TYPE, &ad5446_powerdown_mode_enum),
107	{ }
108};
109EXPORT_SYMBOL_NS_GPL(ad5446_ext_info_powerdown, "IIO_AD5446");
110
111static int ad5446_read_raw(struct iio_dev *indio_dev,
112			   struct iio_chan_spec const *chan,
113			   int *val,
114			   int *val2,
115			   long m)
116{
117	struct ad5446_state *st = iio_priv(indio_dev);
118
119	switch (m) {
120	case IIO_CHAN_INFO_RAW:
121		*val = st->cached_val >> chan->scan_type.shift;
122		return IIO_VAL_INT;
123	case IIO_CHAN_INFO_SCALE:
124		*val = st->vref_mv;
125		*val2 = chan->scan_type.realbits;
126		return IIO_VAL_FRACTIONAL_LOG2;
127	}
128	return -EINVAL;
129}
130
131static int ad5446_write_dac_raw(struct iio_dev *indio_dev,
132				const struct iio_chan_spec *chan,
133				int val)
134{
135	struct ad5446_state *st = iio_priv(indio_dev);
136
137	if (val >= (1 << chan->scan_type.realbits) || val < 0)
138		return -EINVAL;
139
140	val <<= chan->scan_type.shift;
141	guard(mutex)(&st->lock);
142
143	st->cached_val = val;
144	if (st->pwr_down)
145		return 0;
146
147	return st->chip_info->write(st, val);
148}
149
150static int ad5446_write_raw(struct iio_dev *indio_dev,
151			    struct iio_chan_spec const *chan, int val,
152			    int val2, long mask)
153{
154	switch (mask) {
155	case IIO_CHAN_INFO_RAW:
156		return ad5446_write_dac_raw(indio_dev, chan, val);
157	default:
158		return -EINVAL;
159	}
160}
161
162static const struct iio_info ad5446_info = {
163	.read_raw = ad5446_read_raw,
164	.write_raw = ad5446_write_raw,
165};
166
167int ad5446_probe(struct device *dev, const char *name,
168		 const struct ad5446_chip_info *chip_info)
169{
170	struct ad5446_state *st;
171	struct iio_dev *indio_dev;
172	int ret;
173
174	indio_dev = devm_iio_device_alloc(dev, sizeof(*st));
175	if (!indio_dev)
176		return -ENOMEM;
177
178	st = iio_priv(indio_dev);
179	st->chip_info = chip_info;
180
181	st->dev = dev;
182
183	indio_dev->name = name;
184	indio_dev->info = &ad5446_info;
185	indio_dev->modes = INDIO_DIRECT_MODE;
186	indio_dev->channels = &st->chip_info->channel;
187	indio_dev->num_channels = 1;
188
189	ret = devm_mutex_init(dev, &st->lock);
190	if (ret)
191		return ret;
192
193	st->pwr_down_mode = MODE_PWRDWN_1k;
194
195	ret = devm_regulator_get_enable_read_voltage(dev, "vcc");
196	if (ret < 0 && ret != -ENODEV)
197		return ret;
198	if (ret == -ENODEV) {
199		if (!chip_info->int_vref_mv)
200			return dev_err_probe(dev, ret,
201					     "reference voltage unspecified\n");
202
203		st->vref_mv = chip_info->int_vref_mv;
204	} else {
205		st->vref_mv = ret / 1000;
206	}
207
208	return devm_iio_device_register(dev, indio_dev);
209}
210EXPORT_SYMBOL_NS_GPL(ad5446_probe, "IIO_AD5446");
211
212MODULE_AUTHOR("Michael Hennerich <michael.hennerich@analog.com>");
213MODULE_DESCRIPTION("Analog Devices CORE AD5446 DAC and similar devices");
214MODULE_LICENSE("GPL v2");