drivers: power: report battery voltage in AOSP compatible format
[GitHub/mt8127/android_kernel_alcatel_ttab.git] / drivers / iio / adc / ad7476.c
CommitLineData
349282d8
MH
1/*
2 * AD7466/7/8 AD7476/5/7/8 (A) SPI ADC driver
3 *
4 * Copyright 2010 Analog Devices Inc.
5 *
6 * Licensed under the GPL-2 or later.
7 */
8
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9#include <linux/device.h>
10#include <linux/kernel.h>
11#include <linux/slab.h>
12#include <linux/sysfs.h>
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13#include <linux/spi/spi.h>
14#include <linux/regulator/consumer.h>
15#include <linux/err.h>
99c97852 16#include <linux/module.h>
349282d8 17
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18#include <linux/iio/iio.h>
19#include <linux/iio/sysfs.h>
20#include <linux/iio/buffer.h>
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21#include <linux/iio/trigger_consumer.h>
22#include <linux/iio/triggered_buffer.h>
349282d8 23
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24#define RES_MASK(bits) ((1 << (bits)) - 1)
25
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26struct ad7476_state;
27
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28struct ad7476_chip_info {
29 unsigned int int_vref_uv;
30 struct iio_chan_spec channel[2];
87c5b10f 31 void (*reset)(struct ad7476_state *);
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32};
33
34struct ad7476_state {
35 struct spi_device *spi;
36 const struct ad7476_chip_info *chip_info;
37 struct regulator *reg;
38 struct spi_transfer xfer;
39 struct spi_message msg;
40 /*
41 * DMA (thus cache coherency maintenance) requires the
42 * transfer buffers to live in their own cache lines.
43 * Make the buffer large enough for one 16 bit sample and one 64 bit
44 * aligned 64 bit timestamp.
45 */
46 unsigned char data[ALIGN(2, sizeof(s64)) + sizeof(s64)]
47 ____cacheline_aligned;
48};
49
50enum ad7476_supported_device_ids {
87c5b10f 51 ID_AD7091R,
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52 ID_AD7276,
53 ID_AD7277,
54 ID_AD7278,
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55 ID_AD7466,
56 ID_AD7467,
57 ID_AD7468,
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58 ID_AD7495,
59 ID_AD7940,
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60};
61
62static irqreturn_t ad7476_trigger_handler(int irq, void *p)
63{
64 struct iio_poll_func *pf = p;
65 struct iio_dev *indio_dev = pf->indio_dev;
66 struct ad7476_state *st = iio_priv(indio_dev);
67 s64 time_ns;
68 int b_sent;
69
70 b_sent = spi_sync(st->spi, &st->msg);
71 if (b_sent < 0)
72 goto done;
73
74 time_ns = iio_get_time_ns();
75
76 if (indio_dev->scan_timestamp)
77 ((s64 *)st->data)[1] = time_ns;
78
84b36ce5 79 iio_push_to_buffers(indio_dev, st->data);
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80done:
81 iio_trigger_notify_done(indio_dev->trig);
82
83 return IRQ_HANDLED;
84}
349282d8 85
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86static void ad7091_reset(struct ad7476_state *st)
87{
88 /* Any transfers with 8 scl cycles will reset the device */
89 spi_read(st->spi, st->data, 1);
90}
91
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92static int ad7476_scan_direct(struct ad7476_state *st)
93{
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94 int ret;
95
668413e9 96 ret = spi_sync(st->spi, &st->msg);
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97 if (ret)
98 return ret;
99
610a407c 100 return be16_to_cpup((__be16 *)st->data);
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101}
102
84f79ecb 103static int ad7476_read_raw(struct iio_dev *indio_dev,
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104 struct iio_chan_spec const *chan,
105 int *val,
106 int *val2,
107 long m)
349282d8 108{
349282d8 109 int ret;
84f79ecb 110 struct ad7476_state *st = iio_priv(indio_dev);
cb093e44 111 int scale_uv;
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112
113 switch (m) {
b11f98ff 114 case IIO_CHAN_INFO_RAW:
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115 mutex_lock(&indio_dev->mlock);
116 if (iio_buffer_enabled(indio_dev))
78c32ed3 117 ret = -EBUSY;
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118 else
119 ret = ad7476_scan_direct(st);
84f79ecb 120 mutex_unlock(&indio_dev->mlock);
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121
122 if (ret < 0)
123 return ret;
124 *val = (ret >> st->chip_info->channel[0].scan_type.shift) &
125 RES_MASK(st->chip_info->channel[0].scan_type.realbits);
126 return IIO_VAL_INT;
c8a9f805 127 case IIO_CHAN_INFO_SCALE:
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LPC
128 if (!st->chip_info->int_vref_uv) {
129 scale_uv = regulator_get_voltage(st->reg);
130 if (scale_uv < 0)
131 return scale_uv;
132 } else {
133 scale_uv = st->chip_info->int_vref_uv;
134 }
135 scale_uv >>= chan->scan_type.realbits;
136 *val = scale_uv / 1000;
137 *val2 = (scale_uv % 1000) * 1000;
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138 return IIO_VAL_INT_PLUS_MICRO;
139 }
140 return -EINVAL;
349282d8 141}
349282d8 142
8c1033f7 143#define _AD7476_CHAN(bits, _shift, _info_mask_sep) \
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144 { \
145 .type = IIO_VOLTAGE, \
146 .indexed = 1, \
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147 .info_mask_separate = _info_mask_sep, \
148 .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE), \
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149 .scan_type = { \
150 .sign = 'u', \
4c337de8 151 .realbits = (bits), \
85871cd8 152 .storagebits = 16, \
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153 .shift = (_shift), \
154 .endianness = IIO_BE, \
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155 }, \
156}
157
87c5b10f 158#define AD7476_CHAN(bits) _AD7476_CHAN((bits), 13 - (bits), \
8c1033f7 159 BIT(IIO_CHAN_INFO_RAW))
87c5b10f 160#define AD7940_CHAN(bits) _AD7476_CHAN((bits), 15 - (bits), \
8c1033f7 161 BIT(IIO_CHAN_INFO_RAW))
87c5b10f 162#define AD7091R_CHAN(bits) _AD7476_CHAN((bits), 16 - (bits), 0)
4c337de8 163
349282d8 164static const struct ad7476_chip_info ad7476_chip_info_tbl[] = {
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165 [ID_AD7091R] = {
166 .channel[0] = AD7091R_CHAN(12),
167 .channel[1] = IIO_CHAN_SOFT_TIMESTAMP(1),
168 .reset = ad7091_reset,
169 },
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170 [ID_AD7276] = {
171 .channel[0] = AD7940_CHAN(12),
172 .channel[1] = IIO_CHAN_SOFT_TIMESTAMP(1),
173 },
174 [ID_AD7277] = {
175 .channel[0] = AD7940_CHAN(10),
176 .channel[1] = IIO_CHAN_SOFT_TIMESTAMP(1),
177 },
178 [ID_AD7278] = {
179 .channel[0] = AD7940_CHAN(8),
180 .channel[1] = IIO_CHAN_SOFT_TIMESTAMP(1),
181 },
349282d8 182 [ID_AD7466] = {
85871cd8 183 .channel[0] = AD7476_CHAN(12),
c5e0819e 184 .channel[1] = IIO_CHAN_SOFT_TIMESTAMP(1),
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185 },
186 [ID_AD7467] = {
85871cd8 187 .channel[0] = AD7476_CHAN(10),
c5e0819e 188 .channel[1] = IIO_CHAN_SOFT_TIMESTAMP(1),
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189 },
190 [ID_AD7468] = {
85871cd8 191 .channel[0] = AD7476_CHAN(8),
c5e0819e 192 .channel[1] = IIO_CHAN_SOFT_TIMESTAMP(1),
349282d8 193 },
349282d8 194 [ID_AD7495] = {
85871cd8 195 .channel[0] = AD7476_CHAN(12),
c5e0819e 196 .channel[1] = IIO_CHAN_SOFT_TIMESTAMP(1),
cb093e44 197 .int_vref_uv = 2500000,
349282d8 198 },
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199 [ID_AD7940] = {
200 .channel[0] = AD7940_CHAN(14),
201 .channel[1] = IIO_CHAN_SOFT_TIMESTAMP(1),
202 },
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203};
204
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205static const struct iio_info ad7476_info = {
206 .driver_module = THIS_MODULE,
207 .read_raw = &ad7476_read_raw,
208};
209
fc52692c 210static int ad7476_probe(struct spi_device *spi)
349282d8 211{
349282d8 212 struct ad7476_state *st;
67688105 213 struct iio_dev *indio_dev;
cb093e44 214 int ret;
349282d8 215
7cbb7537 216 indio_dev = iio_device_alloc(sizeof(*st));
67688105 217 if (indio_dev == NULL) {
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218 ret = -ENOMEM;
219 goto error_ret;
220 }
67688105 221 st = iio_priv(indio_dev);
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222 st->chip_info =
223 &ad7476_chip_info_tbl[spi_get_device_id(spi)->driver_data];
224
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225 st->reg = regulator_get(&spi->dev, "vcc");
226 if (IS_ERR(st->reg)) {
227 ret = PTR_ERR(st->reg);
228 goto error_free_dev;
229 }
230
231 ret = regulator_enable(st->reg);
232 if (ret)
233 goto error_put_reg;
349282d8 234
38f71aa9 235 spi_set_drvdata(spi, indio_dev);
349282d8 236
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237 st->spi = spi;
238
ae639830 239 /* Establish that the iio_dev is a child of the spi device */
67688105
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240 indio_dev->dev.parent = &spi->dev;
241 indio_dev->name = spi_get_device_id(spi)->name;
242 indio_dev->modes = INDIO_DIRECT_MODE;
243 indio_dev->channels = st->chip_info->channel;
244 indio_dev->num_channels = 2;
245 indio_dev->info = &ad7476_info;
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246 /* Setup default message */
247
248 st->xfer.rx_buf = &st->data;
c5e0819e 249 st->xfer.len = st->chip_info->channel[0].scan_type.storagebits / 8;
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250
251 spi_message_init(&st->msg);
252 spi_message_add_tail(&st->xfer, &st->msg);
253
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254 ret = iio_triggered_buffer_setup(indio_dev, NULL,
255 &ad7476_trigger_handler, NULL);
349282d8 256 if (ret)
67688105 257 goto error_disable_reg;
349282d8 258
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259 if (st->chip_info->reset)
260 st->chip_info->reset(st);
261
26d25ae3
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262 ret = iio_device_register(indio_dev);
263 if (ret)
264 goto error_ring_unregister;
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265 return 0;
266
26d25ae3 267error_ring_unregister:
7a28fe3c 268 iio_triggered_buffer_cleanup(indio_dev);
349282d8 269error_disable_reg:
cb093e44 270 regulator_disable(st->reg);
349282d8 271error_put_reg:
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272 regulator_put(st->reg);
273error_free_dev:
7cbb7537 274 iio_device_free(indio_dev);
26d25ae3 275
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276error_ret:
277 return ret;
278}
279
fc52692c 280static int ad7476_remove(struct spi_device *spi)
349282d8 281{
67688105
JC
282 struct iio_dev *indio_dev = spi_get_drvdata(spi);
283 struct ad7476_state *st = iio_priv(indio_dev);
67688105 284
d2fffd6c 285 iio_device_unregister(indio_dev);
7a28fe3c 286 iio_triggered_buffer_cleanup(indio_dev);
cb093e44
LPC
287 regulator_disable(st->reg);
288 regulator_put(st->reg);
7cbb7537 289 iio_device_free(indio_dev);
67688105 290
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291 return 0;
292}
293
294static const struct spi_device_id ad7476_id[] = {
87c5b10f 295 {"ad7091r", ID_AD7091R},
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LPC
296 {"ad7273", ID_AD7277},
297 {"ad7274", ID_AD7276},
298 {"ad7276", ID_AD7276},
299 {"ad7277", ID_AD7277},
300 {"ad7278", ID_AD7278},
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301 {"ad7466", ID_AD7466},
302 {"ad7467", ID_AD7467},
303 {"ad7468", ID_AD7468},
fcc7800b
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304 {"ad7475", ID_AD7466},
305 {"ad7476", ID_AD7466},
306 {"ad7476a", ID_AD7466},
307 {"ad7477", ID_AD7467},
308 {"ad7477a", ID_AD7467},
309 {"ad7478", ID_AD7468},
310 {"ad7478a", ID_AD7468},
349282d8 311 {"ad7495", ID_AD7495},
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312 {"ad7910", ID_AD7467},
313 {"ad7920", ID_AD7466},
4c337de8 314 {"ad7940", ID_AD7940},
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315 {}
316};
55e4390c 317MODULE_DEVICE_TABLE(spi, ad7476_id);
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318
319static struct spi_driver ad7476_driver = {
320 .driver = {
321 .name = "ad7476",
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322 .owner = THIS_MODULE,
323 },
324 .probe = ad7476_probe,
fc52692c 325 .remove = ad7476_remove,
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326 .id_table = ad7476_id,
327};
ae6ae6fe 328module_spi_driver(ad7476_driver);
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329
330MODULE_AUTHOR("Michael Hennerich <hennerich@blackfin.uclinux.org>");
ac5332b1 331MODULE_DESCRIPTION("Analog Devices AD7476 and similar 1-channel ADCs");
349282d8 332MODULE_LICENSE("GPL v2");