1
2
3
4
5
6
7
8
9#include <linux/device.h>
10#include <linux/err.h>
11#include <linux/module.h>
12#include <linux/kernel.h>
13#include <linux/spi/spi.h>
14#include <linux/slab.h>
15#include <linux/sysfs.h>
16#include <linux/delay.h>
17#include <linux/iio/iio.h>
18#include <linux/iio/sysfs.h>
19#include <linux/platform_data/ad5755.h>
20
21#define AD5755_NUM_CHANNELS 4
22
23#define AD5755_ADDR(x) ((x) << 16)
24
25#define AD5755_WRITE_REG_DATA(chan) (chan)
26#define AD5755_WRITE_REG_GAIN(chan) (0x08 | (chan))
27#define AD5755_WRITE_REG_OFFSET(chan) (0x10 | (chan))
28#define AD5755_WRITE_REG_CTRL(chan) (0x1c | (chan))
29
30#define AD5755_READ_REG_DATA(chan) (chan)
31#define AD5755_READ_REG_CTRL(chan) (0x4 | (chan))
32#define AD5755_READ_REG_GAIN(chan) (0x8 | (chan))
33#define AD5755_READ_REG_OFFSET(chan) (0xc | (chan))
34#define AD5755_READ_REG_CLEAR(chan) (0x10 | (chan))
35#define AD5755_READ_REG_SLEW(chan) (0x14 | (chan))
36#define AD5755_READ_REG_STATUS 0x18
37#define AD5755_READ_REG_MAIN 0x19
38#define AD5755_READ_REG_DC_DC 0x1a
39
40#define AD5755_CTRL_REG_SLEW 0x0
41#define AD5755_CTRL_REG_MAIN 0x1
42#define AD5755_CTRL_REG_DAC 0x2
43#define AD5755_CTRL_REG_DC_DC 0x3
44#define AD5755_CTRL_REG_SW 0x4
45
46#define AD5755_READ_FLAG 0x800000
47
48#define AD5755_NOOP 0x1CE000
49
50#define AD5755_DAC_INT_EN BIT(8)
51#define AD5755_DAC_CLR_EN BIT(7)
52#define AD5755_DAC_OUT_EN BIT(6)
53#define AD5755_DAC_INT_CURRENT_SENSE_RESISTOR BIT(5)
54#define AD5755_DAC_DC_DC_EN BIT(4)
55#define AD5755_DAC_VOLTAGE_OVERRANGE_EN BIT(3)
56
57#define AD5755_DC_DC_MAXV 0
58#define AD5755_DC_DC_FREQ_SHIFT 2
59#define AD5755_DC_DC_PHASE_SHIFT 4
60#define AD5755_EXT_DC_DC_COMP_RES BIT(6)
61
62#define AD5755_SLEW_STEP_SIZE_SHIFT 0
63#define AD5755_SLEW_RATE_SHIFT 3
64#define AD5755_SLEW_ENABLE BIT(12)
65
66
67
68
69
70
71
72struct ad5755_chip_info {
73 const struct iio_chan_spec channel_template;
74 unsigned int calib_shift;
75 bool has_voltage_out;
76};
77
78
79
80
81
82
83
84
85
86
87struct ad5755_state {
88 struct spi_device *spi;
89 const struct ad5755_chip_info *chip_info;
90 unsigned int pwr_down;
91 unsigned int ctrl[AD5755_NUM_CHANNELS];
92 struct iio_chan_spec channels[AD5755_NUM_CHANNELS];
93
94
95
96
97
98
99 union {
100 u32 d32;
101 u8 d8[4];
102 } data[2] ____cacheline_aligned;
103};
104
105enum ad5755_type {
106 ID_AD5755,
107 ID_AD5757,
108 ID_AD5735,
109 ID_AD5737,
110};
111
112static int ad5755_write_unlocked(struct iio_dev *indio_dev,
113 unsigned int reg, unsigned int val)
114{
115 struct ad5755_state *st = iio_priv(indio_dev);
116
117 st->data[0].d32 = cpu_to_be32((reg << 16) | val);
118
119 return spi_write(st->spi, &st->data[0].d8[1], 3);
120}
121
122static int ad5755_write_ctrl_unlocked(struct iio_dev *indio_dev,
123 unsigned int channel, unsigned int reg, unsigned int val)
124{
125 return ad5755_write_unlocked(indio_dev,
126 AD5755_WRITE_REG_CTRL(channel), (reg << 13) | val);
127}
128
129static int ad5755_write(struct iio_dev *indio_dev, unsigned int reg,
130 unsigned int val)
131{
132 int ret;
133
134 mutex_lock(&indio_dev->mlock);
135 ret = ad5755_write_unlocked(indio_dev, reg, val);
136 mutex_unlock(&indio_dev->mlock);
137
138 return ret;
139}
140
141static int ad5755_write_ctrl(struct iio_dev *indio_dev, unsigned int channel,
142 unsigned int reg, unsigned int val)
143{
144 int ret;
145
146 mutex_lock(&indio_dev->mlock);
147 ret = ad5755_write_ctrl_unlocked(indio_dev, channel, reg, val);
148 mutex_unlock(&indio_dev->mlock);
149
150 return ret;
151}
152
153static int ad5755_read(struct iio_dev *indio_dev, unsigned int addr)
154{
155 struct ad5755_state *st = iio_priv(indio_dev);
156 int ret;
157 struct spi_transfer t[] = {
158 {
159 .tx_buf = &st->data[0].d8[1],
160 .len = 3,
161 .cs_change = 1,
162 }, {
163 .tx_buf = &st->data[1].d8[1],
164 .rx_buf = &st->data[1].d8[1],
165 .len = 3,
166 },
167 };
168
169 mutex_lock(&indio_dev->mlock);
170
171 st->data[0].d32 = cpu_to_be32(AD5755_READ_FLAG | (addr << 16));
172 st->data[1].d32 = cpu_to_be32(AD5755_NOOP);
173
174 ret = spi_sync_transfer(st->spi, t, ARRAY_SIZE(t));
175 if (ret >= 0)
176 ret = be32_to_cpu(st->data[1].d32) & 0xffff;
177
178 mutex_unlock(&indio_dev->mlock);
179
180 return ret;
181}
182
183static int ad5755_update_dac_ctrl(struct iio_dev *indio_dev,
184 unsigned int channel, unsigned int set, unsigned int clr)
185{
186 struct ad5755_state *st = iio_priv(indio_dev);
187 int ret;
188
189 st->ctrl[channel] |= set;
190 st->ctrl[channel] &= ~clr;
191
192 ret = ad5755_write_ctrl_unlocked(indio_dev, channel,
193 AD5755_CTRL_REG_DAC, st->ctrl[channel]);
194
195 return ret;
196}
197
198static int ad5755_set_channel_pwr_down(struct iio_dev *indio_dev,
199 unsigned int channel, bool pwr_down)
200{
201 struct ad5755_state *st = iio_priv(indio_dev);
202 unsigned int mask = BIT(channel);
203
204 mutex_lock(&indio_dev->mlock);
205
206 if ((bool)(st->pwr_down & mask) == pwr_down)
207 goto out_unlock;
208
209 if (!pwr_down) {
210 st->pwr_down &= ~mask;
211 ad5755_update_dac_ctrl(indio_dev, channel,
212 AD5755_DAC_INT_EN | AD5755_DAC_DC_DC_EN, 0);
213 udelay(200);
214 ad5755_update_dac_ctrl(indio_dev, channel,
215 AD5755_DAC_OUT_EN, 0);
216 } else {
217 st->pwr_down |= mask;
218 ad5755_update_dac_ctrl(indio_dev, channel,
219 0, AD5755_DAC_INT_EN | AD5755_DAC_OUT_EN |
220 AD5755_DAC_DC_DC_EN);
221 }
222
223out_unlock:
224 mutex_unlock(&indio_dev->mlock);
225
226 return 0;
227}
228
229static const int ad5755_min_max_table[][2] = {
230 [AD5755_MODE_VOLTAGE_0V_5V] = { 0, 5000 },
231 [AD5755_MODE_VOLTAGE_0V_10V] = { 0, 10000 },
232 [AD5755_MODE_VOLTAGE_PLUSMINUS_5V] = { -5000, 5000 },
233 [AD5755_MODE_VOLTAGE_PLUSMINUS_10V] = { -10000, 10000 },
234 [AD5755_MODE_CURRENT_4mA_20mA] = { 4, 20 },
235 [AD5755_MODE_CURRENT_0mA_20mA] = { 0, 20 },
236 [AD5755_MODE_CURRENT_0mA_24mA] = { 0, 24 },
237};
238
239static void ad5755_get_min_max(struct ad5755_state *st,
240 struct iio_chan_spec const *chan, int *min, int *max)
241{
242 enum ad5755_mode mode = st->ctrl[chan->channel] & 7;
243 *min = ad5755_min_max_table[mode][0];
244 *max = ad5755_min_max_table[mode][1];
245}
246
247static inline int ad5755_get_offset(struct ad5755_state *st,
248 struct iio_chan_spec const *chan)
249{
250 int min, max;
251
252 ad5755_get_min_max(st, chan, &min, &max);
253 return (min * (1 << chan->scan_type.realbits)) / (max - min);
254}
255
256static inline int ad5755_get_scale(struct ad5755_state *st,
257 struct iio_chan_spec const *chan)
258{
259 int min, max;
260
261 ad5755_get_min_max(st, chan, &min, &max);
262 return ((max - min) * 1000000000ULL) >> chan->scan_type.realbits;
263}
264
265static int ad5755_chan_reg_info(struct ad5755_state *st,
266 struct iio_chan_spec const *chan, long info, bool write,
267 unsigned int *reg, unsigned int *shift, unsigned int *offset)
268{
269 switch (info) {
270 case IIO_CHAN_INFO_RAW:
271 if (write)
272 *reg = AD5755_WRITE_REG_DATA(chan->address);
273 else
274 *reg = AD5755_READ_REG_DATA(chan->address);
275 *shift = chan->scan_type.shift;
276 *offset = 0;
277 break;
278 case IIO_CHAN_INFO_CALIBBIAS:
279 if (write)
280 *reg = AD5755_WRITE_REG_OFFSET(chan->address);
281 else
282 *reg = AD5755_READ_REG_OFFSET(chan->address);
283 *shift = st->chip_info->calib_shift;
284 *offset = 32768;
285 break;
286 case IIO_CHAN_INFO_CALIBSCALE:
287 if (write)
288 *reg = AD5755_WRITE_REG_GAIN(chan->address);
289 else
290 *reg = AD5755_READ_REG_GAIN(chan->address);
291 *shift = st->chip_info->calib_shift;
292 *offset = 0;
293 break;
294 default:
295 return -EINVAL;
296 }
297
298 return 0;
299}
300
301static int ad5755_read_raw(struct iio_dev *indio_dev,
302 const struct iio_chan_spec *chan, int *val, int *val2, long info)
303{
304 struct ad5755_state *st = iio_priv(indio_dev);
305 unsigned int reg, shift, offset;
306 int ret;
307
308 switch (info) {
309 case IIO_CHAN_INFO_SCALE:
310 *val = 0;
311 *val2 = ad5755_get_scale(st, chan);
312 return IIO_VAL_INT_PLUS_NANO;
313 case IIO_CHAN_INFO_OFFSET:
314 *val = ad5755_get_offset(st, chan);
315 return IIO_VAL_INT;
316 default:
317 ret = ad5755_chan_reg_info(st, chan, info, false,
318 ®, &shift, &offset);
319 if (ret)
320 return ret;
321
322 ret = ad5755_read(indio_dev, reg);
323 if (ret < 0)
324 return ret;
325
326 *val = (ret - offset) >> shift;
327
328 return IIO_VAL_INT;
329 }
330
331 return -EINVAL;
332}
333
334static int ad5755_write_raw(struct iio_dev *indio_dev,
335 const struct iio_chan_spec *chan, int val, int val2, long info)
336{
337 struct ad5755_state *st = iio_priv(indio_dev);
338 unsigned int shift, reg, offset;
339 int ret;
340
341 ret = ad5755_chan_reg_info(st, chan, info, true,
342 ®, &shift, &offset);
343 if (ret)
344 return ret;
345
346 val <<= shift;
347 val += offset;
348
349 if (val < 0 || val > 0xffff)
350 return -EINVAL;
351
352 return ad5755_write(indio_dev, reg, val);
353}
354
355static ssize_t ad5755_read_powerdown(struct iio_dev *indio_dev, uintptr_t priv,
356 const struct iio_chan_spec *chan, char *buf)
357{
358 struct ad5755_state *st = iio_priv(indio_dev);
359
360 return sprintf(buf, "%d\n",
361 (bool)(st->pwr_down & (1 << chan->channel)));
362}
363
364static ssize_t ad5755_write_powerdown(struct iio_dev *indio_dev, uintptr_t priv,
365 struct iio_chan_spec const *chan, const char *buf, size_t len)
366{
367 bool pwr_down;
368 int ret;
369
370 ret = strtobool(buf, &pwr_down);
371 if (ret)
372 return ret;
373
374 ret = ad5755_set_channel_pwr_down(indio_dev, chan->channel, pwr_down);
375 return ret ? ret : len;
376}
377
378static const struct iio_info ad5755_info = {
379 .read_raw = ad5755_read_raw,
380 .write_raw = ad5755_write_raw,
381 .driver_module = THIS_MODULE,
382};
383
384static const struct iio_chan_spec_ext_info ad5755_ext_info[] = {
385 {
386 .name = "powerdown",
387 .read = ad5755_read_powerdown,
388 .write = ad5755_write_powerdown,
389 },
390 { },
391};
392
393#define AD5755_CHANNEL(_bits) { \
394 .indexed = 1, \
395 .output = 1, \
396 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | \
397 BIT(IIO_CHAN_INFO_SCALE) | \
398 BIT(IIO_CHAN_INFO_OFFSET) | \
399 BIT(IIO_CHAN_INFO_CALIBSCALE) | \
400 BIT(IIO_CHAN_INFO_CALIBBIAS), \
401 .scan_type = IIO_ST('u', (_bits), 16, 16 - (_bits)), \
402 .ext_info = ad5755_ext_info, \
403}
404
405static const struct ad5755_chip_info ad5755_chip_info_tbl[] = {
406 [ID_AD5735] = {
407 .channel_template = AD5755_CHANNEL(14),
408 .has_voltage_out = true,
409 .calib_shift = 4,
410 },
411 [ID_AD5737] = {
412 .channel_template = AD5755_CHANNEL(14),
413 .has_voltage_out = false,
414 .calib_shift = 4,
415 },
416 [ID_AD5755] = {
417 .channel_template = AD5755_CHANNEL(16),
418 .has_voltage_out = true,
419 .calib_shift = 0,
420 },
421 [ID_AD5757] = {
422 .channel_template = AD5755_CHANNEL(16),
423 .has_voltage_out = false,
424 .calib_shift = 0,
425 },
426};
427
428static bool ad5755_is_valid_mode(struct ad5755_state *st, enum ad5755_mode mode)
429{
430 switch (mode) {
431 case AD5755_MODE_VOLTAGE_0V_5V:
432 case AD5755_MODE_VOLTAGE_0V_10V:
433 case AD5755_MODE_VOLTAGE_PLUSMINUS_5V:
434 case AD5755_MODE_VOLTAGE_PLUSMINUS_10V:
435 return st->chip_info->has_voltage_out;
436 case AD5755_MODE_CURRENT_4mA_20mA:
437 case AD5755_MODE_CURRENT_0mA_20mA:
438 case AD5755_MODE_CURRENT_0mA_24mA:
439 return true;
440 default:
441 return false;
442 }
443}
444
445static int ad5755_setup_pdata(struct iio_dev *indio_dev,
446 const struct ad5755_platform_data *pdata)
447{
448 struct ad5755_state *st = iio_priv(indio_dev);
449 unsigned int val;
450 unsigned int i;
451 int ret;
452
453 if (pdata->dc_dc_phase > AD5755_DC_DC_PHASE_90_DEGREE ||
454 pdata->dc_dc_freq > AD5755_DC_DC_FREQ_650kHZ ||
455 pdata->dc_dc_maxv > AD5755_DC_DC_MAXV_29V5)
456 return -EINVAL;
457
458 val = pdata->dc_dc_maxv << AD5755_DC_DC_MAXV;
459 val |= pdata->dc_dc_freq << AD5755_DC_DC_FREQ_SHIFT;
460 val |= pdata->dc_dc_phase << AD5755_DC_DC_PHASE_SHIFT;
461 if (pdata->ext_dc_dc_compenstation_resistor)
462 val |= AD5755_EXT_DC_DC_COMP_RES;
463
464 ret = ad5755_write_ctrl(indio_dev, 0, AD5755_CTRL_REG_DC_DC, val);
465 if (ret < 0)
466 return ret;
467
468 for (i = 0; i < ARRAY_SIZE(pdata->dac); ++i) {
469 val = pdata->dac[i].slew.step_size <<
470 AD5755_SLEW_STEP_SIZE_SHIFT;
471 val |= pdata->dac[i].slew.rate <<
472 AD5755_SLEW_RATE_SHIFT;
473 if (pdata->dac[i].slew.enable)
474 val |= AD5755_SLEW_ENABLE;
475
476 ret = ad5755_write_ctrl(indio_dev, i,
477 AD5755_CTRL_REG_SLEW, val);
478 if (ret < 0)
479 return ret;
480 }
481
482 for (i = 0; i < ARRAY_SIZE(pdata->dac); ++i) {
483 if (!ad5755_is_valid_mode(st, pdata->dac[i].mode))
484 return -EINVAL;
485
486 val = 0;
487 if (!pdata->dac[i].ext_current_sense_resistor)
488 val |= AD5755_DAC_INT_CURRENT_SENSE_RESISTOR;
489 if (pdata->dac[i].enable_voltage_overrange)
490 val |= AD5755_DAC_VOLTAGE_OVERRANGE_EN;
491 val |= pdata->dac[i].mode;
492
493 ret = ad5755_update_dac_ctrl(indio_dev, i, val, 0);
494 if (ret < 0)
495 return ret;
496 }
497
498 return 0;
499}
500
501static bool ad5755_is_voltage_mode(enum ad5755_mode mode)
502{
503 switch (mode) {
504 case AD5755_MODE_VOLTAGE_0V_5V:
505 case AD5755_MODE_VOLTAGE_0V_10V:
506 case AD5755_MODE_VOLTAGE_PLUSMINUS_5V:
507 case AD5755_MODE_VOLTAGE_PLUSMINUS_10V:
508 return true;
509 default:
510 return false;
511 }
512}
513
514static int ad5755_init_channels(struct iio_dev *indio_dev,
515 const struct ad5755_platform_data *pdata)
516{
517 struct ad5755_state *st = iio_priv(indio_dev);
518 struct iio_chan_spec *channels = st->channels;
519 unsigned int i;
520
521 for (i = 0; i < AD5755_NUM_CHANNELS; ++i) {
522 channels[i] = st->chip_info->channel_template;
523 channels[i].channel = i;
524 channels[i].address = i;
525 if (pdata && ad5755_is_voltage_mode(pdata->dac[i].mode))
526 channels[i].type = IIO_VOLTAGE;
527 else
528 channels[i].type = IIO_CURRENT;
529 }
530
531 indio_dev->channels = channels;
532
533 return 0;
534}
535
536#define AD5755_DEFAULT_DAC_PDATA { \
537 .mode = AD5755_MODE_CURRENT_4mA_20mA, \
538 .ext_current_sense_resistor = true, \
539 .enable_voltage_overrange = false, \
540 .slew = { \
541 .enable = false, \
542 .rate = AD5755_SLEW_RATE_64k, \
543 .step_size = AD5755_SLEW_STEP_SIZE_1, \
544 }, \
545 }
546
547static const struct ad5755_platform_data ad5755_default_pdata = {
548 .ext_dc_dc_compenstation_resistor = false,
549 .dc_dc_phase = AD5755_DC_DC_PHASE_ALL_SAME_EDGE,
550 .dc_dc_freq = AD5755_DC_DC_FREQ_410kHZ,
551 .dc_dc_maxv = AD5755_DC_DC_MAXV_23V,
552 .dac = {
553 [0] = AD5755_DEFAULT_DAC_PDATA,
554 [1] = AD5755_DEFAULT_DAC_PDATA,
555 [2] = AD5755_DEFAULT_DAC_PDATA,
556 [3] = AD5755_DEFAULT_DAC_PDATA,
557 },
558};
559
560static int ad5755_probe(struct spi_device *spi)
561{
562 enum ad5755_type type = spi_get_device_id(spi)->driver_data;
563 const struct ad5755_platform_data *pdata = dev_get_platdata(&spi->dev);
564 struct iio_dev *indio_dev;
565 struct ad5755_state *st;
566 int ret;
567
568 indio_dev = iio_device_alloc(sizeof(*st));
569 if (indio_dev == NULL) {
570 dev_err(&spi->dev, "Failed to allocate iio device\n");
571 return -ENOMEM;
572 }
573
574 st = iio_priv(indio_dev);
575 spi_set_drvdata(spi, indio_dev);
576
577 st->chip_info = &ad5755_chip_info_tbl[type];
578 st->spi = spi;
579 st->pwr_down = 0xf;
580
581 indio_dev->dev.parent = &spi->dev;
582 indio_dev->name = spi_get_device_id(spi)->name;
583 indio_dev->info = &ad5755_info;
584 indio_dev->modes = INDIO_DIRECT_MODE;
585 indio_dev->num_channels = AD5755_NUM_CHANNELS;
586
587 if (!pdata)
588 pdata = &ad5755_default_pdata;
589
590 ret = ad5755_init_channels(indio_dev, pdata);
591 if (ret)
592 goto error_free;
593
594 ret = ad5755_setup_pdata(indio_dev, pdata);
595 if (ret)
596 goto error_free;
597
598 ret = iio_device_register(indio_dev);
599 if (ret) {
600 dev_err(&spi->dev, "Failed to register iio device: %d\n", ret);
601 goto error_free;
602 }
603
604 return 0;
605
606error_free:
607 iio_device_free(indio_dev);
608
609 return ret;
610}
611
612static int ad5755_remove(struct spi_device *spi)
613{
614 struct iio_dev *indio_dev = spi_get_drvdata(spi);
615
616 iio_device_unregister(indio_dev);
617 iio_device_free(indio_dev);
618
619 return 0;
620}
621
622static const struct spi_device_id ad5755_id[] = {
623 { "ad5755", ID_AD5755 },
624 { "ad5755-1", ID_AD5755 },
625 { "ad5757", ID_AD5757 },
626 { "ad5735", ID_AD5735 },
627 { "ad5737", ID_AD5737 },
628 {}
629};
630MODULE_DEVICE_TABLE(spi, ad5755_id);
631
632static struct spi_driver ad5755_driver = {
633 .driver = {
634 .name = "ad5755",
635 .owner = THIS_MODULE,
636 },
637 .probe = ad5755_probe,
638 .remove = ad5755_remove,
639 .id_table = ad5755_id,
640};
641module_spi_driver(ad5755_driver);
642
643MODULE_AUTHOR("Lars-Peter Clausen <lars@metafoo.de>");
644MODULE_DESCRIPTION("Analog Devices AD5755/55-1/57/35/37 DAC");
645MODULE_LICENSE("GPL v2");
646
