Commit | Line | Data |
---|---|---|
7c31b984 MH |
1 | /* |
2 | * AD7298 SPI ADC driver | |
3 | * | |
4 | * Copyright 2011 Analog Devices Inc. | |
5 | * | |
6 | * Licensed under the GPL-2. | |
7 | */ | |
8 | ||
7c31b984 MH |
9 | #include <linux/device.h> |
10 | #include <linux/kernel.h> | |
11 | #include <linux/slab.h> | |
12 | #include <linux/sysfs.h> | |
13 | #include <linux/spi/spi.h> | |
14 | #include <linux/regulator/consumer.h> | |
15 | #include <linux/err.h> | |
16 | #include <linux/delay.h> | |
99c97852 | 17 | #include <linux/module.h> |
dc4871ad | 18 | #include <linux/interrupt.h> |
7c31b984 | 19 | |
06458e27 JC |
20 | #include <linux/iio/iio.h> |
21 | #include <linux/iio/sysfs.h> | |
22 | #include <linux/iio/buffer.h> | |
dc4871ad LPC |
23 | #include <linux/iio/trigger_consumer.h> |
24 | #include <linux/iio/triggered_buffer.h> | |
7c31b984 | 25 | |
709ab36e | 26 | #include <linux/platform_data/ad7298.h> |
7c31b984 | 27 | |
dc4871ad LPC |
28 | #define AD7298_WRITE (1 << 15) /* write to the control register */ |
29 | #define AD7298_REPEAT (1 << 14) /* repeated conversion enable */ | |
30 | #define AD7298_CH(x) (1 << (13 - (x))) /* channel select */ | |
31 | #define AD7298_TSENSE (1 << 5) /* temperature conversion enable */ | |
32 | #define AD7298_EXTREF (1 << 2) /* external reference enable */ | |
33 | #define AD7298_TAVG (1 << 1) /* temperature sensor averaging enable */ | |
34 | #define AD7298_PDD (1 << 0) /* partial power down enable */ | |
35 | ||
36 | #define AD7298_MAX_CHAN 8 | |
37 | #define AD7298_BITS 12 | |
38 | #define AD7298_STORAGE_BITS 16 | |
39 | #define AD7298_INTREF_mV 2500 | |
40 | ||
41 | #define AD7298_CH_TEMP 9 | |
42 | ||
43 | #define RES_MASK(bits) ((1 << (bits)) - 1) | |
44 | ||
45 | struct ad7298_state { | |
46 | struct spi_device *spi; | |
47 | struct regulator *reg; | |
48 | unsigned ext_ref; | |
49 | struct spi_transfer ring_xfer[10]; | |
50 | struct spi_transfer scan_single_xfer[3]; | |
51 | struct spi_message ring_msg; | |
52 | struct spi_message scan_single_msg; | |
53 | /* | |
54 | * DMA (thus cache coherency maintenance) requires the | |
55 | * transfer buffers to live in their own cache lines. | |
56 | */ | |
be7fd3b8 JC |
57 | __be16 rx_buf[12] ____cacheline_aligned; |
58 | __be16 tx_buf[2]; | |
dc4871ad LPC |
59 | }; |
60 | ||
95e48f77 JC |
61 | #define AD7298_V_CHAN(index) \ |
62 | { \ | |
63 | .type = IIO_VOLTAGE, \ | |
64 | .indexed = 1, \ | |
65 | .channel = index, \ | |
40dd676d JC |
66 | .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \ |
67 | .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE), \ | |
95e48f77 JC |
68 | .address = index, \ |
69 | .scan_index = index, \ | |
70 | .scan_type = { \ | |
71 | .sign = 'u', \ | |
72 | .realbits = 12, \ | |
73 | .storagebits = 16, \ | |
ca654638 | 74 | .endianness = IIO_BE, \ |
95e48f77 JC |
75 | }, \ |
76 | } | |
77 | ||
f4e4b955 | 78 | static const struct iio_chan_spec ad7298_channels[] = { |
95e48f77 JC |
79 | { |
80 | .type = IIO_TEMP, | |
81 | .indexed = 1, | |
82 | .channel = 0, | |
40dd676d JC |
83 | .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | |
84 | BIT(IIO_CHAN_INFO_SCALE) | | |
85 | BIT(IIO_CHAN_INFO_OFFSET), | |
d045b9d2 LPC |
86 | .address = AD7298_CH_TEMP, |
87 | .scan_index = -1, | |
95e48f77 JC |
88 | .scan_type = { |
89 | .sign = 's', | |
90 | .realbits = 32, | |
91 | .storagebits = 32, | |
92 | }, | |
93 | }, | |
94 | AD7298_V_CHAN(0), | |
95 | AD7298_V_CHAN(1), | |
96 | AD7298_V_CHAN(2), | |
97 | AD7298_V_CHAN(3), | |
98 | AD7298_V_CHAN(4), | |
99 | AD7298_V_CHAN(5), | |
100 | AD7298_V_CHAN(6), | |
101 | AD7298_V_CHAN(7), | |
01a99e18 MH |
102 | IIO_CHAN_SOFT_TIMESTAMP(8), |
103 | }; | |
104 | ||
dc4871ad LPC |
105 | /** |
106 | * ad7298_update_scan_mode() setup the spi transfer buffer for the new scan mask | |
107 | **/ | |
108 | static int ad7298_update_scan_mode(struct iio_dev *indio_dev, | |
109 | const unsigned long *active_scan_mask) | |
110 | { | |
111 | struct ad7298_state *st = iio_priv(indio_dev); | |
112 | int i, m; | |
113 | unsigned short command; | |
114 | int scan_count; | |
115 | ||
116 | /* Now compute overall size */ | |
117 | scan_count = bitmap_weight(active_scan_mask, indio_dev->masklength); | |
118 | ||
119 | command = AD7298_WRITE | st->ext_ref; | |
120 | ||
121 | for (i = 0, m = AD7298_CH(0); i < AD7298_MAX_CHAN; i++, m >>= 1) | |
122 | if (test_bit(i, active_scan_mask)) | |
123 | command |= m; | |
124 | ||
125 | st->tx_buf[0] = cpu_to_be16(command); | |
126 | ||
127 | /* build spi ring message */ | |
128 | st->ring_xfer[0].tx_buf = &st->tx_buf[0]; | |
129 | st->ring_xfer[0].len = 2; | |
130 | st->ring_xfer[0].cs_change = 1; | |
131 | st->ring_xfer[1].tx_buf = &st->tx_buf[1]; | |
132 | st->ring_xfer[1].len = 2; | |
133 | st->ring_xfer[1].cs_change = 1; | |
134 | ||
135 | spi_message_init(&st->ring_msg); | |
136 | spi_message_add_tail(&st->ring_xfer[0], &st->ring_msg); | |
137 | spi_message_add_tail(&st->ring_xfer[1], &st->ring_msg); | |
138 | ||
139 | for (i = 0; i < scan_count; i++) { | |
140 | st->ring_xfer[i + 2].rx_buf = &st->rx_buf[i]; | |
141 | st->ring_xfer[i + 2].len = 2; | |
142 | st->ring_xfer[i + 2].cs_change = 1; | |
143 | spi_message_add_tail(&st->ring_xfer[i + 2], &st->ring_msg); | |
144 | } | |
145 | /* make sure last transfer cs_change is not set */ | |
146 | st->ring_xfer[i + 1].cs_change = 0; | |
147 | ||
148 | return 0; | |
149 | } | |
150 | ||
151 | /** | |
152 | * ad7298_trigger_handler() bh of trigger launched polling to ring buffer | |
153 | * | |
154 | * Currently there is no option in this driver to disable the saving of | |
155 | * timestamps within the ring. | |
156 | **/ | |
157 | static irqreturn_t ad7298_trigger_handler(int irq, void *p) | |
158 | { | |
159 | struct iio_poll_func *pf = p; | |
160 | struct iio_dev *indio_dev = pf->indio_dev; | |
161 | struct ad7298_state *st = iio_priv(indio_dev); | |
dc4871ad LPC |
162 | int b_sent; |
163 | ||
164 | b_sent = spi_sync(st->spi, &st->ring_msg); | |
165 | if (b_sent) | |
166 | goto done; | |
167 | ||
85ec2372 LPC |
168 | iio_push_to_buffers_with_timestamp(indio_dev, st->rx_buf, |
169 | iio_get_time_ns()); | |
dc4871ad LPC |
170 | |
171 | done: | |
172 | iio_trigger_notify_done(indio_dev->trig); | |
173 | ||
174 | return IRQ_HANDLED; | |
175 | } | |
176 | ||
7c31b984 MH |
177 | static int ad7298_scan_direct(struct ad7298_state *st, unsigned ch) |
178 | { | |
179 | int ret; | |
180 | st->tx_buf[0] = cpu_to_be16(AD7298_WRITE | st->ext_ref | | |
181 | (AD7298_CH(0) >> ch)); | |
182 | ||
183 | ret = spi_sync(st->spi, &st->scan_single_msg); | |
184 | if (ret) | |
185 | return ret; | |
186 | ||
187 | return be16_to_cpu(st->rx_buf[0]); | |
188 | } | |
189 | ||
01a99e18 | 190 | static int ad7298_scan_temp(struct ad7298_state *st, int *val) |
7c31b984 | 191 | { |
01a10e04 | 192 | int ret; |
c1a75288 | 193 | __be16 buf; |
7c31b984 | 194 | |
c1a75288 | 195 | buf = cpu_to_be16(AD7298_WRITE | AD7298_TSENSE | |
01a99e18 | 196 | AD7298_TAVG | st->ext_ref); |
7c31b984 | 197 | |
c1a75288 | 198 | ret = spi_write(st->spi, (u8 *)&buf, 2); |
01a99e18 | 199 | if (ret) |
7c31b984 MH |
200 | return ret; |
201 | ||
c1a75288 | 202 | buf = cpu_to_be16(0); |
7c31b984 | 203 | |
c1a75288 | 204 | ret = spi_write(st->spi, (u8 *)&buf, 2); |
01a99e18 MH |
205 | if (ret) |
206 | return ret; | |
7c31b984 | 207 | |
7c31b984 | 208 | usleep_range(101, 1000); /* sleep > 100us */ |
01a99e18 | 209 | |
c1a75288 | 210 | ret = spi_read(st->spi, (u8 *)&buf, 2); |
01a99e18 MH |
211 | if (ret) |
212 | return ret; | |
7c31b984 | 213 | |
01a10e04 | 214 | *val = sign_extend32(be16_to_cpu(buf), 11); |
7c31b984 | 215 | |
01a10e04 LPC |
216 | return 0; |
217 | } | |
218 | ||
219 | static int ad7298_get_ref_voltage(struct ad7298_state *st) | |
220 | { | |
221 | int vref; | |
7c31b984 | 222 | |
01a10e04 LPC |
223 | if (st->ext_ref) { |
224 | vref = regulator_get_voltage(st->reg); | |
225 | if (vref < 0) | |
226 | return vref; | |
7c31b984 | 227 | |
01a10e04 | 228 | return vref / 1000; |
7c31b984 | 229 | } else { |
01a10e04 | 230 | return AD7298_INTREF_mV; |
7c31b984 | 231 | } |
01a99e18 | 232 | } |
7c31b984 | 233 | |
84f79ecb | 234 | static int ad7298_read_raw(struct iio_dev *indio_dev, |
01a99e18 MH |
235 | struct iio_chan_spec const *chan, |
236 | int *val, | |
237 | int *val2, | |
238 | long m) | |
7c31b984 | 239 | { |
01a99e18 | 240 | int ret; |
84f79ecb | 241 | struct ad7298_state *st = iio_priv(indio_dev); |
01a99e18 MH |
242 | |
243 | switch (m) { | |
b11f98ff | 244 | case IIO_CHAN_INFO_RAW: |
84f79ecb | 245 | mutex_lock(&indio_dev->mlock); |
389ac488 JC |
246 | if (indio_dev->currentmode == INDIO_BUFFER_TRIGGERED) { |
247 | ret = -EBUSY; | |
01a99e18 MH |
248 | } else { |
249 | if (chan->address == AD7298_CH_TEMP) | |
250 | ret = ad7298_scan_temp(st, val); | |
251 | else | |
252 | ret = ad7298_scan_direct(st, chan->address); | |
253 | } | |
84f79ecb | 254 | mutex_unlock(&indio_dev->mlock); |
01a99e18 MH |
255 | |
256 | if (ret < 0) | |
257 | return ret; | |
258 | ||
259 | if (chan->address != AD7298_CH_TEMP) | |
260 | *val = ret & RES_MASK(AD7298_BITS); | |
261 | ||
262 | return IIO_VAL_INT; | |
c8a9f805 JC |
263 | case IIO_CHAN_INFO_SCALE: |
264 | switch (chan->type) { | |
265 | case IIO_VOLTAGE: | |
01a10e04 | 266 | *val = ad7298_get_ref_voltage(st); |
2e334600 LPC |
267 | *val2 = chan->scan_type.realbits; |
268 | return IIO_VAL_FRACTIONAL_LOG2; | |
c8a9f805 | 269 | case IIO_TEMP: |
01a10e04 LPC |
270 | *val = ad7298_get_ref_voltage(st); |
271 | *val2 = 10; | |
272 | return IIO_VAL_FRACTIONAL; | |
c8a9f805 JC |
273 | default: |
274 | return -EINVAL; | |
275 | } | |
01a10e04 LPC |
276 | case IIO_CHAN_INFO_OFFSET: |
277 | *val = 1093 - 2732500 / ad7298_get_ref_voltage(st); | |
278 | return IIO_VAL_INT; | |
01a99e18 MH |
279 | } |
280 | return -EINVAL; | |
7c31b984 | 281 | } |
7c31b984 | 282 | |
6fe8135f JC |
283 | static const struct iio_info ad7298_info = { |
284 | .read_raw = &ad7298_read_raw, | |
d045b9d2 | 285 | .update_scan_mode = ad7298_update_scan_mode, |
6fe8135f JC |
286 | .driver_module = THIS_MODULE, |
287 | }; | |
288 | ||
fc52692c | 289 | static int ad7298_probe(struct spi_device *spi) |
7c31b984 MH |
290 | { |
291 | struct ad7298_platform_data *pdata = spi->dev.platform_data; | |
292 | struct ad7298_state *st; | |
7abe9007 | 293 | struct iio_dev *indio_dev; |
2e334600 | 294 | int ret; |
7c31b984 | 295 | |
7abe9007 | 296 | indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*st)); |
cc4a48e4 MH |
297 | if (indio_dev == NULL) |
298 | return -ENOMEM; | |
299 | ||
300 | st = iio_priv(indio_dev); | |
7c31b984 | 301 | |
2e334600 LPC |
302 | if (pdata && pdata->ext_ref) |
303 | st->ext_ref = AD7298_EXTREF; | |
304 | ||
305 | if (st->ext_ref) { | |
7abe9007 SK |
306 | st->reg = devm_regulator_get(&spi->dev, "vref"); |
307 | if (IS_ERR(st->reg)) | |
308 | return PTR_ERR(st->reg); | |
309 | ||
7c31b984 MH |
310 | ret = regulator_enable(st->reg); |
311 | if (ret) | |
7abe9007 | 312 | return ret; |
7c31b984 MH |
313 | } |
314 | ||
cc4a48e4 | 315 | spi_set_drvdata(spi, indio_dev); |
7c31b984 | 316 | |
7c31b984 MH |
317 | st->spi = spi; |
318 | ||
cc4a48e4 MH |
319 | indio_dev->name = spi_get_device_id(spi)->name; |
320 | indio_dev->dev.parent = &spi->dev; | |
cc4a48e4 MH |
321 | indio_dev->modes = INDIO_DIRECT_MODE; |
322 | indio_dev->channels = ad7298_channels; | |
323 | indio_dev->num_channels = ARRAY_SIZE(ad7298_channels); | |
6fe8135f | 324 | indio_dev->info = &ad7298_info; |
7c31b984 MH |
325 | |
326 | /* Setup default message */ | |
327 | ||
328 | st->scan_single_xfer[0].tx_buf = &st->tx_buf[0]; | |
329 | st->scan_single_xfer[0].len = 2; | |
330 | st->scan_single_xfer[0].cs_change = 1; | |
331 | st->scan_single_xfer[1].tx_buf = &st->tx_buf[1]; | |
332 | st->scan_single_xfer[1].len = 2; | |
333 | st->scan_single_xfer[1].cs_change = 1; | |
334 | st->scan_single_xfer[2].rx_buf = &st->rx_buf[0]; | |
335 | st->scan_single_xfer[2].len = 2; | |
336 | ||
337 | spi_message_init(&st->scan_single_msg); | |
338 | spi_message_add_tail(&st->scan_single_xfer[0], &st->scan_single_msg); | |
339 | spi_message_add_tail(&st->scan_single_xfer[1], &st->scan_single_msg); | |
340 | spi_message_add_tail(&st->scan_single_xfer[2], &st->scan_single_msg); | |
341 | ||
dc4871ad LPC |
342 | ret = iio_triggered_buffer_setup(indio_dev, NULL, |
343 | &ad7298_trigger_handler, NULL); | |
7c31b984 | 344 | if (ret) |
cc4a48e4 | 345 | goto error_disable_reg; |
7c31b984 | 346 | |
26d25ae3 JC |
347 | ret = iio_device_register(indio_dev); |
348 | if (ret) | |
d045b9d2 | 349 | goto error_cleanup_ring; |
cc4a48e4 | 350 | |
7c31b984 MH |
351 | return 0; |
352 | ||
353 | error_cleanup_ring: | |
dc4871ad | 354 | iio_triggered_buffer_cleanup(indio_dev); |
7c31b984 | 355 | error_disable_reg: |
2e334600 | 356 | if (st->ext_ref) |
7c31b984 | 357 | regulator_disable(st->reg); |
cc4a48e4 | 358 | |
7c31b984 MH |
359 | return ret; |
360 | } | |
361 | ||
fc52692c | 362 | static int ad7298_remove(struct spi_device *spi) |
7c31b984 | 363 | { |
cc4a48e4 MH |
364 | struct iio_dev *indio_dev = spi_get_drvdata(spi); |
365 | struct ad7298_state *st = iio_priv(indio_dev); | |
7c31b984 | 366 | |
d2fffd6c | 367 | iio_device_unregister(indio_dev); |
dc4871ad | 368 | iio_triggered_buffer_cleanup(indio_dev); |
7abe9007 | 369 | if (st->ext_ref) |
7c31b984 | 370 | regulator_disable(st->reg); |
cc4a48e4 | 371 | |
7c31b984 MH |
372 | return 0; |
373 | } | |
374 | ||
375 | static const struct spi_device_id ad7298_id[] = { | |
376 | {"ad7298", 0}, | |
377 | {} | |
378 | }; | |
55e4390c | 379 | MODULE_DEVICE_TABLE(spi, ad7298_id); |
7c31b984 MH |
380 | |
381 | static struct spi_driver ad7298_driver = { | |
382 | .driver = { | |
383 | .name = "ad7298", | |
7c31b984 MH |
384 | .owner = THIS_MODULE, |
385 | }, | |
386 | .probe = ad7298_probe, | |
fc52692c | 387 | .remove = ad7298_remove, |
7c31b984 MH |
388 | .id_table = ad7298_id, |
389 | }; | |
ae6ae6fe | 390 | module_spi_driver(ad7298_driver); |
7c31b984 MH |
391 | |
392 | MODULE_AUTHOR("Michael Hennerich <hennerich@blackfin.uclinux.org>"); | |
393 | MODULE_DESCRIPTION("Analog Devices AD7298 ADC"); | |
394 | MODULE_LICENSE("GPL v2"); |