2 * AD7787/AD7788/AD7789/AD7790/AD7791 SPI ADC driver
4 * Copyright 2012 Analog Devices Inc.
5 * Author: Lars-Peter Clausen <lars@metafoo.de>
7 * Licensed under the GPL-2.
10 #include <linux/interrupt.h>
11 #include <linux/device.h>
12 #include <linux/kernel.h>
13 #include <linux/slab.h>
14 #include <linux/sysfs.h>
15 #include <linux/spi/spi.h>
16 #include <linux/regulator/consumer.h>
17 #include <linux/err.h>
18 #include <linux/sched.h>
19 #include <linux/delay.h>
20 #include <linux/module.h>
22 #include <linux/iio/iio.h>
23 #include <linux/iio/sysfs.h>
24 #include <linux/iio/buffer.h>
25 #include <linux/iio/trigger.h>
26 #include <linux/iio/trigger_consumer.h>
27 #include <linux/iio/triggered_buffer.h>
28 #include <linux/iio/adc/ad_sigma_delta.h>
30 #include <linux/platform_data/ad7791.h>
32 #define AD7791_REG_COMM 0x0 /* For writes */
33 #define AD7791_REG_STATUS 0x0 /* For reads */
34 #define AD7791_REG_MODE 0x1
35 #define AD7791_REG_FILTER 0x2
36 #define AD7791_REG_DATA 0x3
38 #define AD7791_MODE_CONTINUOUS 0x00
39 #define AD7791_MODE_SINGLE 0x02
40 #define AD7791_MODE_POWERDOWN 0x03
42 #define AD7791_CH_AIN1P_AIN1N 0x00
43 #define AD7791_CH_AIN2 0x01
44 #define AD7791_CH_AIN1N_AIN1N 0x02
45 #define AD7791_CH_AVDD_MONITOR 0x03
47 #define AD7791_FILTER_CLK_DIV_1 (0x0 << 4)
48 #define AD7791_FILTER_CLK_DIV_2 (0x1 << 4)
49 #define AD7791_FILTER_CLK_DIV_4 (0x2 << 4)
50 #define AD7791_FILTER_CLK_DIV_8 (0x3 << 4)
51 #define AD7791_FILTER_CLK_MASK (0x3 << 4)
52 #define AD7791_FILTER_RATE_120 0x0
53 #define AD7791_FILTER_RATE_100 0x1
54 #define AD7791_FILTER_RATE_33_3 0x2
55 #define AD7791_FILTER_RATE_20 0x3
56 #define AD7791_FILTER_RATE_16_6 0x4
57 #define AD7791_FILTER_RATE_16_7 0x5
58 #define AD7791_FILTER_RATE_13_3 0x6
59 #define AD7791_FILTER_RATE_9_5 0x7
60 #define AD7791_FILTER_RATE_MASK 0x7
62 #define AD7791_MODE_BUFFER BIT(1)
63 #define AD7791_MODE_UNIPOLAR BIT(2)
64 #define AD7791_MODE_BURNOUT BIT(3)
65 #define AD7791_MODE_SEL_MASK (0x3 << 6)
66 #define AD7791_MODE_SEL(x) ((x) << 6)
68 #define DECLARE_AD7787_CHANNELS(name, bits, storagebits) \
69 const struct iio_chan_spec name[] = { \
70 AD_SD_DIFF_CHANNEL(0, 0, 0, AD7791_CH_AIN1P_AIN1N, \
71 (bits), (storagebits), 0), \
72 AD_SD_CHANNEL(1, 1, AD7791_CH_AIN2, (bits), (storagebits), 0), \
73 AD_SD_SHORTED_CHANNEL(2, 0, AD7791_CH_AIN1N_AIN1N, \
74 (bits), (storagebits), 0), \
75 AD_SD_SUPPLY_CHANNEL(3, 2, AD7791_CH_AVDD_MONITOR, \
76 (bits), (storagebits), 0), \
77 IIO_CHAN_SOFT_TIMESTAMP(4), \
80 #define DECLARE_AD7791_CHANNELS(name, bits, storagebits) \
81 const struct iio_chan_spec name[] = { \
82 AD_SD_DIFF_CHANNEL(0, 0, 0, AD7791_CH_AIN1P_AIN1N, \
83 (bits), (storagebits), 0), \
84 AD_SD_SHORTED_CHANNEL(1, 0, AD7791_CH_AIN1N_AIN1N, \
85 (bits), (storagebits), 0), \
86 AD_SD_SUPPLY_CHANNEL(2, 1, AD7791_CH_AVDD_MONITOR, \
87 (bits), (storagebits), 0), \
88 IIO_CHAN_SOFT_TIMESTAMP(3), \
91 static DECLARE_AD7787_CHANNELS(ad7787_channels, 24, 32);
92 static DECLARE_AD7791_CHANNELS(ad7790_channels, 16, 16);
93 static DECLARE_AD7791_CHANNELS(ad7791_channels, 24, 32);
103 enum ad7791_chip_info_flags {
104 AD7791_FLAG_HAS_FILTER = (1 << 0),
105 AD7791_FLAG_HAS_BUFFER = (1 << 1),
106 AD7791_FLAG_HAS_UNIPOLAR = (1 << 2),
107 AD7791_FLAG_HAS_BURNOUT = (1 << 3),
110 struct ad7791_chip_info {
111 const struct iio_chan_spec *channels;
112 unsigned int num_channels;
113 enum ad7791_chip_info_flags flags;
116 static const struct ad7791_chip_info ad7791_chip_infos[] = {
118 .channels = ad7787_channels,
119 .num_channels = ARRAY_SIZE(ad7787_channels),
120 .flags = AD7791_FLAG_HAS_FILTER | AD7791_FLAG_HAS_BUFFER |
121 AD7791_FLAG_HAS_UNIPOLAR | AD7791_FLAG_HAS_BURNOUT,
124 .channels = ad7790_channels,
125 .num_channels = ARRAY_SIZE(ad7790_channels),
126 .flags = AD7791_FLAG_HAS_UNIPOLAR,
129 .channels = ad7791_channels,
130 .num_channels = ARRAY_SIZE(ad7791_channels),
131 .flags = AD7791_FLAG_HAS_UNIPOLAR,
134 .channels = ad7790_channels,
135 .num_channels = ARRAY_SIZE(ad7790_channels),
136 .flags = AD7791_FLAG_HAS_FILTER | AD7791_FLAG_HAS_BUFFER |
137 AD7791_FLAG_HAS_BURNOUT,
140 .channels = ad7791_channels,
141 .num_channels = ARRAY_SIZE(ad7791_channels),
142 .flags = AD7791_FLAG_HAS_FILTER | AD7791_FLAG_HAS_BUFFER |
143 AD7791_FLAG_HAS_UNIPOLAR | AD7791_FLAG_HAS_BURNOUT,
147 struct ad7791_state {
148 struct ad_sigma_delta sd;
152 struct regulator *reg;
153 const struct ad7791_chip_info *info;
156 static struct ad7791_state *ad_sigma_delta_to_ad7791(struct ad_sigma_delta *sd)
158 return container_of(sd, struct ad7791_state, sd);
161 static int ad7791_set_channel(struct ad_sigma_delta *sd, unsigned int channel)
163 ad_sd_set_comm(sd, channel);
168 static int ad7791_set_mode(struct ad_sigma_delta *sd,
169 enum ad_sigma_delta_mode mode)
171 struct ad7791_state *st = ad_sigma_delta_to_ad7791(sd);
174 case AD_SD_MODE_CONTINUOUS:
175 mode = AD7791_MODE_CONTINUOUS;
177 case AD_SD_MODE_SINGLE:
178 mode = AD7791_MODE_SINGLE;
180 case AD_SD_MODE_IDLE:
181 case AD_SD_MODE_POWERDOWN:
182 mode = AD7791_MODE_POWERDOWN;
186 st->mode &= ~AD7791_MODE_SEL_MASK;
187 st->mode |= AD7791_MODE_SEL(mode);
189 return ad_sd_write_reg(sd, AD7791_REG_MODE, sizeof(st->mode), st->mode);
192 static const struct ad_sigma_delta_info ad7791_sigma_delta_info = {
193 .set_channel = ad7791_set_channel,
194 .set_mode = ad7791_set_mode,
195 .has_registers = true,
200 static int ad7791_read_raw(struct iio_dev *indio_dev,
201 const struct iio_chan_spec *chan, int *val, int *val2, long info)
203 struct ad7791_state *st = iio_priv(indio_dev);
204 bool unipolar = !!(st->mode & AD7791_MODE_UNIPOLAR);
207 case IIO_CHAN_INFO_RAW:
208 return ad_sigma_delta_single_conversion(indio_dev, chan, val);
209 case IIO_CHAN_INFO_OFFSET:
211 * Unipolar: 0 to VREF
212 * Bipolar -VREF to VREF
217 *val = -(1 << (chan->scan_type.realbits - 1));
219 case IIO_CHAN_INFO_SCALE:
220 /* The monitor channel uses an internal reference. */
221 if (chan->address == AD7791_CH_AVDD_MONITOR) {
223 * The signal is attenuated by a factor of 5 and
224 * compared against a 1.17V internal reference.
230 voltage_uv = regulator_get_voltage(st->reg);
234 *val = voltage_uv / 1000;
237 *val2 = chan->scan_type.realbits;
239 *val2 = chan->scan_type.realbits - 1;
241 return IIO_VAL_FRACTIONAL_LOG2;
247 static IIO_CONST_ATTR_SAMP_FREQ_AVAIL("120 100 33.3 20 16.7 16.6 13.3 9.5");
249 static struct attribute *ad7791_attributes[] = {
250 &iio_const_attr_sampling_frequency_available.dev_attr.attr,
254 static const struct attribute_group ad7791_attribute_group = {
255 .attrs = ad7791_attributes,
258 static const struct iio_info ad7791_info = {
259 .read_raw = &ad7791_read_raw,
260 .attrs = &ad7791_attribute_group,
261 .validate_trigger = ad_sd_validate_trigger,
262 .driver_module = THIS_MODULE,
265 static const struct iio_info ad7791_no_filter_info = {
266 .read_raw = &ad7791_read_raw,
267 .validate_trigger = ad_sd_validate_trigger,
268 .driver_module = THIS_MODULE,
271 static int ad7791_setup(struct ad7791_state *st,
272 struct ad7791_platform_data *pdata)
274 /* Set to poweron-reset default values */
275 st->mode = AD7791_MODE_BUFFER;
276 st->filter = AD7791_FILTER_RATE_16_6;
281 if ((st->info->flags & AD7791_FLAG_HAS_BUFFER) && !pdata->buffered)
282 st->mode &= ~AD7791_MODE_BUFFER;
284 if ((st->info->flags & AD7791_FLAG_HAS_BURNOUT) &&
285 pdata->burnout_current)
286 st->mode |= AD7791_MODE_BURNOUT;
288 if ((st->info->flags & AD7791_FLAG_HAS_UNIPOLAR) && pdata->unipolar)
289 st->mode |= AD7791_MODE_UNIPOLAR;
291 return ad_sd_write_reg(&st->sd, AD7791_REG_MODE, sizeof(st->mode),
295 static int ad7791_probe(struct spi_device *spi)
297 struct ad7791_platform_data *pdata = spi->dev.platform_data;
298 struct iio_dev *indio_dev;
299 struct ad7791_state *st;
303 dev_err(&spi->dev, "Missing IRQ.\n");
307 indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*st));
311 st = iio_priv(indio_dev);
313 st->reg = devm_regulator_get(&spi->dev, "refin");
315 return PTR_ERR(st->reg);
317 ret = regulator_enable(st->reg);
321 st->info = &ad7791_chip_infos[spi_get_device_id(spi)->driver_data];
322 ad_sd_init(&st->sd, indio_dev, spi, &ad7791_sigma_delta_info);
324 spi_set_drvdata(spi, indio_dev);
326 indio_dev->dev.parent = &spi->dev;
327 indio_dev->dev.of_node = spi->dev.of_node;
328 indio_dev->name = spi_get_device_id(spi)->name;
329 indio_dev->modes = INDIO_DIRECT_MODE;
330 indio_dev->channels = st->info->channels;
331 indio_dev->num_channels = st->info->num_channels;
332 if (st->info->flags & AD7791_FLAG_HAS_FILTER)
333 indio_dev->info = &ad7791_info;
335 indio_dev->info = &ad7791_no_filter_info;
337 ret = ad_sd_setup_buffer_and_trigger(indio_dev);
339 goto error_disable_reg;
341 ret = ad7791_setup(st, pdata);
343 goto error_remove_trigger;
345 ret = iio_device_register(indio_dev);
347 goto error_remove_trigger;
351 error_remove_trigger:
352 ad_sd_cleanup_buffer_and_trigger(indio_dev);
354 regulator_disable(st->reg);
359 static int ad7791_remove(struct spi_device *spi)
361 struct iio_dev *indio_dev = spi_get_drvdata(spi);
362 struct ad7791_state *st = iio_priv(indio_dev);
364 iio_device_unregister(indio_dev);
365 ad_sd_cleanup_buffer_and_trigger(indio_dev);
367 regulator_disable(st->reg);
372 static const struct spi_device_id ad7791_spi_ids[] = {
373 { "ad7787", AD7787 },
374 { "ad7788", AD7788 },
375 { "ad7789", AD7789 },
376 { "ad7790", AD7790 },
377 { "ad7791", AD7791 },
380 MODULE_DEVICE_TABLE(spi, ad7791_spi_ids);
382 static struct spi_driver ad7791_driver = {
386 .probe = ad7791_probe,
387 .remove = ad7791_remove,
388 .id_table = ad7791_spi_ids,
390 module_spi_driver(ad7791_driver);
392 MODULE_AUTHOR("Lars-Peter Clausen <lars@metafoo.de>");
393 MODULE_DESCRIPTION("Analog Device AD7787/AD7788/AD7789/AD7790/AD7791 ADC driver");
394 MODULE_LICENSE("GPL v2");