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9#include <linux/interrupt.h>
10#include <linux/device.h>
11#include <linux/kernel.h>
12#include <linux/slab.h>
13#include <linux/sysfs.h>
14#include <linux/spi/spi.h>
15#include <linux/regulator/consumer.h>
16#include <linux/err.h>
17#include <linux/sched.h>
18#include <linux/gpio.h>
19#include <linux/module.h>
20
21#include <linux/iio/iio.h>
22#include <linux/iio/sysfs.h>
23#include <linux/iio/adc/ad_sigma_delta.h>
24
25#include "ad7780.h"
26
27#define AD7780_RDY (1 << 7)
28#define AD7780_FILTER (1 << 6)
29#define AD7780_ERR (1 << 5)
30#define AD7780_ID1 (1 << 4)
31#define AD7780_ID0 (1 << 3)
32#define AD7780_GAIN (1 << 2)
33#define AD7780_PAT1 (1 << 1)
34#define AD7780_PAT0 (1 << 0)
35
36struct ad7780_chip_info {
37 struct iio_chan_spec channel;
38 unsigned int pattern_mask;
39 unsigned int pattern;
40};
41
42struct ad7780_state {
43 const struct ad7780_chip_info *chip_info;
44 struct regulator *reg;
45 int powerdown_gpio;
46 unsigned int gain;
47 u16 int_vref_mv;
48
49 struct ad_sigma_delta sd;
50};
51
52enum ad7780_supported_device_ids {
53 ID_AD7170,
54 ID_AD7171,
55 ID_AD7780,
56 ID_AD7781,
57};
58
59static struct ad7780_state *ad_sigma_delta_to_ad7780(struct ad_sigma_delta *sd)
60{
61 return container_of(sd, struct ad7780_state, sd);
62}
63
64static int ad7780_set_mode(struct ad_sigma_delta *sigma_delta,
65 enum ad_sigma_delta_mode mode)
66{
67 struct ad7780_state *st = ad_sigma_delta_to_ad7780(sigma_delta);
68 unsigned val;
69
70 switch (mode) {
71 case AD_SD_MODE_SINGLE:
72 case AD_SD_MODE_CONTINUOUS:
73 val = 1;
74 break;
75 default:
76 val = 0;
77 break;
78 }
79
80 if (gpio_is_valid(st->powerdown_gpio))
81 gpio_set_value(st->powerdown_gpio, val);
82
83 return 0;
84}
85
86static int ad7780_read_raw(struct iio_dev *indio_dev,
87 struct iio_chan_spec const *chan,
88 int *val,
89 int *val2,
90 long m)
91{
92 struct ad7780_state *st = iio_priv(indio_dev);
93
94 switch (m) {
95 case IIO_CHAN_INFO_RAW:
96 return ad_sigma_delta_single_conversion(indio_dev, chan, val);
97 case IIO_CHAN_INFO_SCALE:
98 *val = st->int_vref_mv * st->gain;
99 *val2 = chan->scan_type.realbits - 1;
100 return IIO_VAL_FRACTIONAL_LOG2;
101 case IIO_CHAN_INFO_OFFSET:
102 *val -= (1 << (chan->scan_type.realbits - 1));
103 return IIO_VAL_INT;
104 }
105
106 return -EINVAL;
107}
108
109static int ad7780_postprocess_sample(struct ad_sigma_delta *sigma_delta,
110 unsigned int raw_sample)
111{
112 struct ad7780_state *st = ad_sigma_delta_to_ad7780(sigma_delta);
113 const struct ad7780_chip_info *chip_info = st->chip_info;
114
115 if ((raw_sample & AD7780_ERR) ||
116 ((raw_sample & chip_info->pattern_mask) != chip_info->pattern))
117 return -EIO;
118
119 if (raw_sample & AD7780_GAIN)
120 st->gain = 1;
121 else
122 st->gain = 128;
123
124 return 0;
125}
126
127static const struct ad_sigma_delta_info ad7780_sigma_delta_info = {
128 .set_mode = ad7780_set_mode,
129 .postprocess_sample = ad7780_postprocess_sample,
130 .has_registers = false,
131};
132
133#define AD7780_CHANNEL(bits, wordsize) \
134 AD_SD_CHANNEL(1, 0, 0, bits, 32, wordsize - bits)
135
136static const struct ad7780_chip_info ad7780_chip_info_tbl[] = {
137 [ID_AD7170] = {
138 .channel = AD7780_CHANNEL(12, 24),
139 .pattern = 0x5,
140 .pattern_mask = 0x7,
141 },
142 [ID_AD7171] = {
143 .channel = AD7780_CHANNEL(16, 24),
144 .pattern = 0x5,
145 .pattern_mask = 0x7,
146 },
147 [ID_AD7780] = {
148 .channel = AD7780_CHANNEL(24, 32),
149 .pattern = 0x1,
150 .pattern_mask = 0x3,
151 },
152 [ID_AD7781] = {
153 .channel = AD7780_CHANNEL(20, 32),
154 .pattern = 0x1,
155 .pattern_mask = 0x3,
156 },
157};
158
159static const struct iio_info ad7780_info = {
160 .read_raw = &ad7780_read_raw,
161 .driver_module = THIS_MODULE,
162};
163
164static int ad7780_probe(struct spi_device *spi)
165{
166 struct ad7780_platform_data *pdata = spi->dev.platform_data;
167 struct ad7780_state *st;
168 struct iio_dev *indio_dev;
169 int ret, voltage_uv = 0;
170
171 indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*st));
172 if (indio_dev == NULL)
173 return -ENOMEM;
174
175 st = iio_priv(indio_dev);
176 st->gain = 1;
177
178 ad_sd_init(&st->sd, indio_dev, spi, &ad7780_sigma_delta_info);
179
180 st->reg = devm_regulator_get(&spi->dev, "vcc");
181 if (!IS_ERR(st->reg)) {
182 ret = regulator_enable(st->reg);
183 if (ret)
184 return ret;
185
186 voltage_uv = regulator_get_voltage(st->reg);
187 }
188
189 st->chip_info =
190 &ad7780_chip_info_tbl[spi_get_device_id(spi)->driver_data];
191
192 if (pdata && pdata->vref_mv)
193 st->int_vref_mv = pdata->vref_mv;
194 else if (voltage_uv)
195 st->int_vref_mv = voltage_uv / 1000;
196 else
197 dev_warn(&spi->dev, "reference voltage unspecified\n");
198
199 spi_set_drvdata(spi, indio_dev);
200
201 indio_dev->dev.parent = &spi->dev;
202 indio_dev->name = spi_get_device_id(spi)->name;
203 indio_dev->modes = INDIO_DIRECT_MODE;
204 indio_dev->channels = &st->chip_info->channel;
205 indio_dev->num_channels = 1;
206 indio_dev->info = &ad7780_info;
207
208 if (pdata && gpio_is_valid(pdata->gpio_pdrst)) {
209
210 ret = devm_gpio_request_one(&spi->dev, pdata->gpio_pdrst,
211 GPIOF_OUT_INIT_LOW, "AD7780 /PDRST");
212 if (ret) {
213 dev_err(&spi->dev, "failed to request GPIO PDRST\n");
214 goto error_disable_reg;
215 }
216 st->powerdown_gpio = pdata->gpio_pdrst;
217 } else {
218 st->powerdown_gpio = -1;
219 }
220
221 ret = ad_sd_setup_buffer_and_trigger(indio_dev);
222 if (ret)
223 goto error_disable_reg;
224
225 ret = iio_device_register(indio_dev);
226 if (ret)
227 goto error_cleanup_buffer_and_trigger;
228
229 return 0;
230
231error_cleanup_buffer_and_trigger:
232 ad_sd_cleanup_buffer_and_trigger(indio_dev);
233error_disable_reg:
234 if (!IS_ERR(st->reg))
235 regulator_disable(st->reg);
236
237 return ret;
238}
239
240static int ad7780_remove(struct spi_device *spi)
241{
242 struct iio_dev *indio_dev = spi_get_drvdata(spi);
243 struct ad7780_state *st = iio_priv(indio_dev);
244
245 iio_device_unregister(indio_dev);
246 ad_sd_cleanup_buffer_and_trigger(indio_dev);
247
248 if (!IS_ERR(st->reg))
249 regulator_disable(st->reg);
250
251 return 0;
252}
253
254static const struct spi_device_id ad7780_id[] = {
255 {"ad7170", ID_AD7170},
256 {"ad7171", ID_AD7171},
257 {"ad7780", ID_AD7780},
258 {"ad7781", ID_AD7781},
259 {}
260};
261MODULE_DEVICE_TABLE(spi, ad7780_id);
262
263static struct spi_driver ad7780_driver = {
264 .driver = {
265 .name = "ad7780",
266 .owner = THIS_MODULE,
267 },
268 .probe = ad7780_probe,
269 .remove = ad7780_remove,
270 .id_table = ad7780_id,
271};
272module_spi_driver(ad7780_driver);
273
274MODULE_AUTHOR("Michael Hennerich <hennerich@blackfin.uclinux.org>");
275MODULE_DESCRIPTION("Analog Devices AD7780 and similar ADCs");
276MODULE_LICENSE("GPL v2");
277
