ltc2664.c 19 KB

123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990919293949596979899100101102103104105106107108109110111112113114115116117118119120121122123124125126127128129130131132133134135136137138139140141142143144145146147148149150151152153154155156157158159160161162163164165166167168169170171172173174175176177178179180181182183184185186187188189190191192193194195196197198199200201202203204205206207208209210211212213214215216217218219220221222223224225226227228229230231232233234235236237238239240241242243244245246247248249250251252253254255256257258259260261262263264265266267268269270271272273274275276277278279280281282283284285286287288289290291292293294295296297298299300301302303304305306307308309310311312313314315316317318319320321322323324325326327328329330331332333334335336337338339340341342343344345346347348349350351352353354355356357358359360361362363364365366367368369370371372373374375376377378379380381382383384385386387388389390391392393394395396397398399400401402403404405406407408409410411412413414415416417418419420421422423424425426427428429430431432433434435436437438439440441442443444445446447448449450451452453454455456457458459460461462463464465466467468469470471472473474475476477478479480481482483484485486487488489490491492493494495496497498499500501502503504505506507508509510511512513514515516517518519520521522523524525526527528529530531532533534535536537538539540541542543544545546547548549550551552553554555556557558559560561562563564565566567568569570571572573574575576577578579580581582583584585586587588589590591592593594595596597598599600601602603604605606607608609610611612613614615616617618619620621622623624625626627628629630631632633634635636637638639640641642643644645646647648649650651652653654655656657658659660661662663664665666667668669670671672673674675676677678679680681682683684685686687688689690691692693694695696697698699700701702703704705706707708709710711712713714715716717718719720721722723724725726727728729730731732733734735736
  1. // SPDX-License-Identifier: GPL-2.0
  2. /*
  3. * LTC2664 4 channel, 12-/16-Bit Voltage Output SoftSpan DAC driver
  4. * LTC2672 5 channel, 12-/16-Bit Current Output Softspan DAC driver
  5. *
  6. * Copyright 2024 Analog Devices Inc.
  7. */
  8. #include <linux/bitfield.h>
  9. #include <linux/cleanup.h>
  10. #include <linux/device.h>
  11. #include <linux/gpio/consumer.h>
  12. #include <linux/iio/iio.h>
  13. #include <linux/kernel.h>
  14. #include <linux/math64.h>
  15. #include <linux/module.h>
  16. #include <linux/mod_devicetable.h>
  17. #include <linux/mutex.h>
  18. #include <linux/property.h>
  19. #include <linux/regmap.h>
  20. #include <linux/regulator/consumer.h>
  21. #include <linux/spi/spi.h>
  22. #define LTC2664_CMD_WRITE_N(n) (0x00 + (n))
  23. #define LTC2664_CMD_UPDATE_N(n) (0x10 + (n))
  24. #define LTC2664_CMD_WRITE_N_UPDATE_ALL 0x20
  25. #define LTC2664_CMD_WRITE_N_UPDATE_N(n) (0x30 + (n))
  26. #define LTC2664_CMD_POWER_DOWN_N(n) (0x40 + (n))
  27. #define LTC2664_CMD_POWER_DOWN_ALL 0x50
  28. #define LTC2664_CMD_SPAN_N(n) (0x60 + (n))
  29. #define LTC2664_CMD_CONFIG 0x70
  30. #define LTC2664_CMD_MUX 0xB0
  31. #define LTC2664_CMD_TOGGLE_SEL 0xC0
  32. #define LTC2664_CMD_GLOBAL_TOGGLE 0xD0
  33. #define LTC2664_CMD_NO_OPERATION 0xF0
  34. #define LTC2664_REF_DISABLE 0x0001
  35. #define LTC2664_MSPAN_SOFTSPAN 7
  36. #define LTC2672_MAX_CHANNEL 5
  37. #define LTC2672_MAX_SPAN 7
  38. #define LTC2672_SCALE_MULTIPLIER(n) (50 * BIT(n))
  39. enum {
  40. LTC2664_SPAN_RANGE_0V_5V,
  41. LTC2664_SPAN_RANGE_0V_10V,
  42. LTC2664_SPAN_RANGE_M5V_5V,
  43. LTC2664_SPAN_RANGE_M10V_10V,
  44. LTC2664_SPAN_RANGE_M2V5_2V5,
  45. };
  46. enum {
  47. LTC2664_INPUT_A,
  48. LTC2664_INPUT_B,
  49. LTC2664_INPUT_B_AVAIL,
  50. LTC2664_POWERDOWN,
  51. LTC2664_POWERDOWN_MODE,
  52. LTC2664_TOGGLE_EN,
  53. LTC2664_GLOBAL_TOGGLE,
  54. };
  55. static const u16 ltc2664_mspan_lut[8][2] = {
  56. { LTC2664_SPAN_RANGE_M10V_10V, 32768 }, /* MPS2=0, MPS1=0, MSP0=0 (0)*/
  57. { LTC2664_SPAN_RANGE_M5V_5V, 32768 }, /* MPS2=0, MPS1=0, MSP0=1 (1)*/
  58. { LTC2664_SPAN_RANGE_M2V5_2V5, 32768 }, /* MPS2=0, MPS1=1, MSP0=0 (2)*/
  59. { LTC2664_SPAN_RANGE_0V_10V, 0 }, /* MPS2=0, MPS1=1, MSP0=1 (3)*/
  60. { LTC2664_SPAN_RANGE_0V_10V, 32768 }, /* MPS2=1, MPS1=0, MSP0=0 (4)*/
  61. { LTC2664_SPAN_RANGE_0V_5V, 0 }, /* MPS2=1, MPS1=0, MSP0=1 (5)*/
  62. { LTC2664_SPAN_RANGE_0V_5V, 32768 }, /* MPS2=1, MPS1=1, MSP0=0 (6)*/
  63. { LTC2664_SPAN_RANGE_0V_5V, 0 } /* MPS2=1, MPS1=1, MSP0=1 (7)*/
  64. };
  65. struct ltc2664_state;
  66. struct ltc2664_chip_info {
  67. const char *name;
  68. int (*scale_get)(const struct ltc2664_state *st, int c);
  69. int (*offset_get)(const struct ltc2664_state *st, int c);
  70. int measurement_type;
  71. unsigned int num_channels;
  72. const int (*span_helper)[2];
  73. unsigned int num_span;
  74. unsigned int internal_vref_mv;
  75. bool manual_span_support;
  76. bool rfsadj_support;
  77. };
  78. struct ltc2664_chan {
  79. /* indicates if the channel should be toggled */
  80. bool toggle_chan;
  81. /* indicates if the channel is in powered down state */
  82. bool powerdown;
  83. /* span code of the channel */
  84. u8 span;
  85. /* raw data of the current state of the chip registers (A/B) */
  86. u16 raw[2];
  87. };
  88. struct ltc2664_state {
  89. struct spi_device *spi;
  90. struct regmap *regmap;
  91. struct ltc2664_chan channels[LTC2672_MAX_CHANNEL];
  92. /* lock to protect against multiple access to the device and shared data */
  93. struct mutex lock;
  94. const struct ltc2664_chip_info *chip_info;
  95. struct iio_chan_spec *iio_channels;
  96. int vref_mv;
  97. u32 rfsadj_ohms;
  98. u32 toggle_sel;
  99. bool global_toggle;
  100. };
  101. static const int ltc2664_span_helper[][2] = {
  102. { 0, 5000 },
  103. { 0, 10000 },
  104. { -5000, 5000 },
  105. { -10000, 10000 },
  106. { -2500, 2500 },
  107. };
  108. static const int ltc2672_span_helper[][2] = {
  109. { 0, 0 },
  110. { 0, 3125 },
  111. { 0, 6250 },
  112. { 0, 12500 },
  113. { 0, 25000 },
  114. { 0, 50000 },
  115. { 0, 100000 },
  116. { 0, 200000 },
  117. { 0, 300000 },
  118. };
  119. static int ltc2664_scale_get(const struct ltc2664_state *st, int c)
  120. {
  121. const struct ltc2664_chan *chan = &st->channels[c];
  122. const int (*span_helper)[2] = st->chip_info->span_helper;
  123. int span, fs;
  124. span = chan->span;
  125. if (span < 0)
  126. return span;
  127. fs = span_helper[span][1] - span_helper[span][0];
  128. return fs * st->vref_mv / 2500;
  129. }
  130. static int ltc2672_scale_get(const struct ltc2664_state *st, int c)
  131. {
  132. const struct ltc2664_chan *chan = &st->channels[c];
  133. int span, fs;
  134. span = chan->span - 1;
  135. if (span < 0)
  136. return span;
  137. fs = 1000 * st->vref_mv;
  138. if (span == LTC2672_MAX_SPAN)
  139. return mul_u64_u32_div(4800, fs, st->rfsadj_ohms);
  140. return mul_u64_u32_div(LTC2672_SCALE_MULTIPLIER(span), fs, st->rfsadj_ohms);
  141. }
  142. static int ltc2664_offset_get(const struct ltc2664_state *st, int c)
  143. {
  144. const struct ltc2664_chan *chan = &st->channels[c];
  145. int span;
  146. span = chan->span;
  147. if (span < 0)
  148. return span;
  149. if (st->chip_info->span_helper[span][0] < 0)
  150. return -32768;
  151. return 0;
  152. }
  153. static int ltc2664_dac_code_write(struct ltc2664_state *st, u32 chan, u32 input,
  154. u16 code)
  155. {
  156. struct ltc2664_chan *c = &st->channels[chan];
  157. int ret, reg;
  158. guard(mutex)(&st->lock);
  159. /* select the correct input register to write to */
  160. if (c->toggle_chan) {
  161. ret = regmap_write(st->regmap, LTC2664_CMD_TOGGLE_SEL,
  162. input << chan);
  163. if (ret)
  164. return ret;
  165. }
  166. /*
  167. * If in toggle mode the dac should be updated by an
  168. * external signal (or sw toggle) and not here.
  169. */
  170. if (st->toggle_sel & BIT(chan))
  171. reg = LTC2664_CMD_WRITE_N(chan);
  172. else
  173. reg = LTC2664_CMD_WRITE_N_UPDATE_N(chan);
  174. ret = regmap_write(st->regmap, reg, code);
  175. if (ret)
  176. return ret;
  177. c->raw[input] = code;
  178. if (c->toggle_chan) {
  179. ret = regmap_write(st->regmap, LTC2664_CMD_TOGGLE_SEL,
  180. st->toggle_sel);
  181. if (ret)
  182. return ret;
  183. }
  184. return 0;
  185. }
  186. static void ltc2664_dac_code_read(struct ltc2664_state *st, u32 chan, u32 input,
  187. u32 *code)
  188. {
  189. guard(mutex)(&st->lock);
  190. *code = st->channels[chan].raw[input];
  191. }
  192. static const int ltc2664_raw_range[] = { 0, 1, U16_MAX };
  193. static int ltc2664_read_avail(struct iio_dev *indio_dev,
  194. struct iio_chan_spec const *chan,
  195. const int **vals, int *type, int *length,
  196. long info)
  197. {
  198. switch (info) {
  199. case IIO_CHAN_INFO_RAW:
  200. *vals = ltc2664_raw_range;
  201. *type = IIO_VAL_INT;
  202. return IIO_AVAIL_RANGE;
  203. default:
  204. return -EINVAL;
  205. }
  206. }
  207. static int ltc2664_read_raw(struct iio_dev *indio_dev,
  208. struct iio_chan_spec const *chan, int *val,
  209. int *val2, long info)
  210. {
  211. struct ltc2664_state *st = iio_priv(indio_dev);
  212. switch (info) {
  213. case IIO_CHAN_INFO_RAW:
  214. ltc2664_dac_code_read(st, chan->channel, LTC2664_INPUT_A, val);
  215. return IIO_VAL_INT;
  216. case IIO_CHAN_INFO_OFFSET:
  217. *val = st->chip_info->offset_get(st, chan->channel);
  218. return IIO_VAL_INT;
  219. case IIO_CHAN_INFO_SCALE:
  220. *val = st->chip_info->scale_get(st, chan->channel);
  221. *val2 = 16;
  222. return IIO_VAL_FRACTIONAL_LOG2;
  223. default:
  224. return -EINVAL;
  225. }
  226. }
  227. static int ltc2664_write_raw(struct iio_dev *indio_dev,
  228. struct iio_chan_spec const *chan, int val,
  229. int val2, long info)
  230. {
  231. struct ltc2664_state *st = iio_priv(indio_dev);
  232. switch (info) {
  233. case IIO_CHAN_INFO_RAW:
  234. if (val > U16_MAX || val < 0)
  235. return -EINVAL;
  236. return ltc2664_dac_code_write(st, chan->channel,
  237. LTC2664_INPUT_A, val);
  238. default:
  239. return -EINVAL;
  240. }
  241. }
  242. static ssize_t ltc2664_reg_bool_get(struct iio_dev *indio_dev,
  243. uintptr_t private,
  244. const struct iio_chan_spec *chan,
  245. char *buf)
  246. {
  247. struct ltc2664_state *st = iio_priv(indio_dev);
  248. u32 val;
  249. guard(mutex)(&st->lock);
  250. switch (private) {
  251. case LTC2664_POWERDOWN:
  252. val = st->channels[chan->channel].powerdown;
  253. return sysfs_emit(buf, "%u\n", val);
  254. case LTC2664_POWERDOWN_MODE:
  255. return sysfs_emit(buf, "42kohm_to_gnd\n");
  256. case LTC2664_TOGGLE_EN:
  257. val = !!(st->toggle_sel & BIT(chan->channel));
  258. return sysfs_emit(buf, "%u\n", val);
  259. case LTC2664_GLOBAL_TOGGLE:
  260. val = st->global_toggle;
  261. return sysfs_emit(buf, "%u\n", val);
  262. default:
  263. return -EINVAL;
  264. }
  265. }
  266. static ssize_t ltc2664_reg_bool_set(struct iio_dev *indio_dev,
  267. uintptr_t private,
  268. const struct iio_chan_spec *chan,
  269. const char *buf, size_t len)
  270. {
  271. struct ltc2664_state *st = iio_priv(indio_dev);
  272. int ret;
  273. bool en;
  274. ret = kstrtobool(buf, &en);
  275. if (ret)
  276. return ret;
  277. guard(mutex)(&st->lock);
  278. switch (private) {
  279. case LTC2664_POWERDOWN:
  280. ret = regmap_write(st->regmap,
  281. en ? LTC2664_CMD_POWER_DOWN_N(chan->channel) :
  282. LTC2664_CMD_UPDATE_N(chan->channel), en);
  283. if (ret)
  284. return ret;
  285. st->channels[chan->channel].powerdown = en;
  286. return len;
  287. case LTC2664_TOGGLE_EN:
  288. if (en)
  289. st->toggle_sel |= BIT(chan->channel);
  290. else
  291. st->toggle_sel &= ~BIT(chan->channel);
  292. ret = regmap_write(st->regmap, LTC2664_CMD_TOGGLE_SEL,
  293. st->toggle_sel);
  294. if (ret)
  295. return ret;
  296. return len;
  297. case LTC2664_GLOBAL_TOGGLE:
  298. ret = regmap_write(st->regmap, LTC2664_CMD_GLOBAL_TOGGLE, en);
  299. if (ret)
  300. return ret;
  301. st->global_toggle = en;
  302. return len;
  303. default:
  304. return -EINVAL;
  305. }
  306. }
  307. static ssize_t ltc2664_dac_input_read(struct iio_dev *indio_dev,
  308. uintptr_t private,
  309. const struct iio_chan_spec *chan,
  310. char *buf)
  311. {
  312. struct ltc2664_state *st = iio_priv(indio_dev);
  313. u32 val;
  314. if (private == LTC2664_INPUT_B_AVAIL)
  315. return sysfs_emit(buf, "[%u %u %u]\n", ltc2664_raw_range[0],
  316. ltc2664_raw_range[1],
  317. ltc2664_raw_range[2] / 4);
  318. ltc2664_dac_code_read(st, chan->channel, private, &val);
  319. return sysfs_emit(buf, "%u\n", val);
  320. }
  321. static ssize_t ltc2664_dac_input_write(struct iio_dev *indio_dev,
  322. uintptr_t private,
  323. const struct iio_chan_spec *chan,
  324. const char *buf, size_t len)
  325. {
  326. struct ltc2664_state *st = iio_priv(indio_dev);
  327. int ret;
  328. u16 val;
  329. if (private == LTC2664_INPUT_B_AVAIL)
  330. return -EINVAL;
  331. ret = kstrtou16(buf, 10, &val);
  332. if (ret)
  333. return ret;
  334. ret = ltc2664_dac_code_write(st, chan->channel, private, val);
  335. if (ret)
  336. return ret;
  337. return len;
  338. }
  339. static int ltc2664_reg_access(struct iio_dev *indio_dev,
  340. unsigned int reg,
  341. unsigned int writeval,
  342. unsigned int *readval)
  343. {
  344. struct ltc2664_state *st = iio_priv(indio_dev);
  345. if (readval)
  346. return -EOPNOTSUPP;
  347. return regmap_write(st->regmap, reg, writeval);
  348. }
  349. #define LTC2664_CHAN_EXT_INFO(_name, _what, _shared, _read, _write) { \
  350. .name = _name, \
  351. .read = (_read), \
  352. .write = (_write), \
  353. .private = (_what), \
  354. .shared = (_shared), \
  355. }
  356. /*
  357. * For toggle mode we only expose the symbol attr (sw_toggle) in case a TGPx is
  358. * not provided in dts.
  359. */
  360. static const struct iio_chan_spec_ext_info ltc2664_toggle_sym_ext_info[] = {
  361. LTC2664_CHAN_EXT_INFO("raw0", LTC2664_INPUT_A, IIO_SEPARATE,
  362. ltc2664_dac_input_read, ltc2664_dac_input_write),
  363. LTC2664_CHAN_EXT_INFO("raw1", LTC2664_INPUT_B, IIO_SEPARATE,
  364. ltc2664_dac_input_read, ltc2664_dac_input_write),
  365. LTC2664_CHAN_EXT_INFO("powerdown", LTC2664_POWERDOWN, IIO_SEPARATE,
  366. ltc2664_reg_bool_get, ltc2664_reg_bool_set),
  367. LTC2664_CHAN_EXT_INFO("powerdown_mode", LTC2664_POWERDOWN_MODE,
  368. IIO_SEPARATE, ltc2664_reg_bool_get, NULL),
  369. LTC2664_CHAN_EXT_INFO("symbol", LTC2664_GLOBAL_TOGGLE, IIO_SEPARATE,
  370. ltc2664_reg_bool_get, ltc2664_reg_bool_set),
  371. LTC2664_CHAN_EXT_INFO("toggle_en", LTC2664_TOGGLE_EN,
  372. IIO_SEPARATE, ltc2664_reg_bool_get,
  373. ltc2664_reg_bool_set),
  374. { }
  375. };
  376. static const struct iio_chan_spec_ext_info ltc2664_ext_info[] = {
  377. LTC2664_CHAN_EXT_INFO("powerdown", LTC2664_POWERDOWN, IIO_SEPARATE,
  378. ltc2664_reg_bool_get, ltc2664_reg_bool_set),
  379. LTC2664_CHAN_EXT_INFO("powerdown_mode", LTC2664_POWERDOWN_MODE,
  380. IIO_SEPARATE, ltc2664_reg_bool_get, NULL),
  381. { }
  382. };
  383. static const struct iio_chan_spec ltc2664_channel_template = {
  384. .indexed = 1,
  385. .output = 1,
  386. .info_mask_separate = BIT(IIO_CHAN_INFO_SCALE) |
  387. BIT(IIO_CHAN_INFO_OFFSET) |
  388. BIT(IIO_CHAN_INFO_RAW),
  389. .info_mask_separate_available = BIT(IIO_CHAN_INFO_RAW),
  390. .ext_info = ltc2664_ext_info,
  391. };
  392. static const struct ltc2664_chip_info ltc2664_chip = {
  393. .name = "ltc2664",
  394. .scale_get = ltc2664_scale_get,
  395. .offset_get = ltc2664_offset_get,
  396. .measurement_type = IIO_VOLTAGE,
  397. .num_channels = 4,
  398. .span_helper = ltc2664_span_helper,
  399. .num_span = ARRAY_SIZE(ltc2664_span_helper),
  400. .internal_vref_mv = 2500,
  401. .manual_span_support = true,
  402. .rfsadj_support = false,
  403. };
  404. static const struct ltc2664_chip_info ltc2672_chip = {
  405. .name = "ltc2672",
  406. .scale_get = ltc2672_scale_get,
  407. .offset_get = ltc2664_offset_get,
  408. .measurement_type = IIO_CURRENT,
  409. .num_channels = 5,
  410. .span_helper = ltc2672_span_helper,
  411. .num_span = ARRAY_SIZE(ltc2672_span_helper),
  412. .internal_vref_mv = 1250,
  413. .manual_span_support = false,
  414. .rfsadj_support = true,
  415. };
  416. static int ltc2664_set_span(const struct ltc2664_state *st, int min, int max,
  417. int chan)
  418. {
  419. const struct ltc2664_chip_info *chip_info = st->chip_info;
  420. const int (*span_helper)[2] = chip_info->span_helper;
  421. int span, ret;
  422. for (span = 0; span < chip_info->num_span; span++) {
  423. if (min == span_helper[span][0] && max == span_helper[span][1])
  424. break;
  425. }
  426. if (span == chip_info->num_span)
  427. return -EINVAL;
  428. ret = regmap_write(st->regmap, LTC2664_CMD_SPAN_N(chan), span);
  429. if (ret)
  430. return ret;
  431. return span;
  432. }
  433. static int ltc2664_channel_config(struct ltc2664_state *st)
  434. {
  435. const struct ltc2664_chip_info *chip_info = st->chip_info;
  436. struct device *dev = &st->spi->dev;
  437. u32 reg, tmp[2], mspan;
  438. int ret;
  439. mspan = LTC2664_MSPAN_SOFTSPAN;
  440. ret = device_property_read_u32(dev, "adi,manual-span-operation-config",
  441. &mspan);
  442. if (!ret) {
  443. if (!chip_info->manual_span_support)
  444. return dev_err_probe(dev, -EINVAL,
  445. "adi,manual-span-operation-config not supported\n");
  446. if (mspan >= ARRAY_SIZE(ltc2664_mspan_lut))
  447. return dev_err_probe(dev, -EINVAL,
  448. "adi,manual-span-operation-config not in range\n");
  449. }
  450. st->rfsadj_ohms = 20000;
  451. ret = device_property_read_u32(dev, "adi,rfsadj-ohms", &st->rfsadj_ohms);
  452. if (!ret) {
  453. if (!chip_info->rfsadj_support)
  454. return dev_err_probe(dev, -EINVAL,
  455. "adi,rfsadj-ohms not supported\n");
  456. if (st->rfsadj_ohms < 19000 || st->rfsadj_ohms > 41000)
  457. return dev_err_probe(dev, -EINVAL,
  458. "adi,rfsadj-ohms not in range\n");
  459. }
  460. device_for_each_child_node_scoped(dev, child) {
  461. struct ltc2664_chan *chan;
  462. ret = fwnode_property_read_u32(child, "reg", &reg);
  463. if (ret)
  464. return dev_err_probe(dev, ret,
  465. "Failed to get reg property\n");
  466. if (reg >= chip_info->num_channels)
  467. return dev_err_probe(dev, -EINVAL,
  468. "reg bigger than: %d\n",
  469. chip_info->num_channels);
  470. chan = &st->channels[reg];
  471. if (fwnode_property_read_bool(child, "adi,toggle-mode")) {
  472. chan->toggle_chan = true;
  473. /* assume sw toggle ABI */
  474. st->iio_channels[reg].ext_info = ltc2664_toggle_sym_ext_info;
  475. /*
  476. * Clear IIO_CHAN_INFO_RAW bit as toggle channels expose
  477. * out_voltage/current_raw{0|1} files.
  478. */
  479. __clear_bit(IIO_CHAN_INFO_RAW,
  480. &st->iio_channels[reg].info_mask_separate);
  481. }
  482. chan->raw[0] = ltc2664_mspan_lut[mspan][1];
  483. chan->raw[1] = ltc2664_mspan_lut[mspan][1];
  484. chan->span = ltc2664_mspan_lut[mspan][0];
  485. ret = fwnode_property_read_u32_array(child, "output-range-microvolt",
  486. tmp, ARRAY_SIZE(tmp));
  487. if (!ret && mspan == LTC2664_MSPAN_SOFTSPAN) {
  488. ret = ltc2664_set_span(st, tmp[0] / 1000, tmp[1] / 1000, reg);
  489. if (ret < 0)
  490. return dev_err_probe(dev, ret,
  491. "Failed to set span\n");
  492. chan->span = ret;
  493. }
  494. ret = fwnode_property_read_u32_array(child, "output-range-microamp",
  495. tmp, ARRAY_SIZE(tmp));
  496. if (!ret) {
  497. ret = ltc2664_set_span(st, 0, tmp[1] / 1000, reg);
  498. if (ret < 0)
  499. return dev_err_probe(dev, ret,
  500. "Failed to set span\n");
  501. chan->span = ret;
  502. }
  503. }
  504. return 0;
  505. }
  506. static int ltc2664_setup(struct ltc2664_state *st)
  507. {
  508. const struct ltc2664_chip_info *chip_info = st->chip_info;
  509. struct gpio_desc *gpio;
  510. int ret, i;
  511. /* If we have a clr/reset pin, use that to reset the chip. */
  512. gpio = devm_gpiod_get_optional(&st->spi->dev, "reset", GPIOD_OUT_HIGH);
  513. if (IS_ERR(gpio))
  514. return dev_err_probe(&st->spi->dev, PTR_ERR(gpio),
  515. "Failed to get reset gpio");
  516. if (gpio) {
  517. fsleep(1000);
  518. gpiod_set_value_cansleep(gpio, 0);
  519. }
  520. /*
  521. * Duplicate the default channel configuration as it can change during
  522. * @ltc2664_channel_config()
  523. */
  524. st->iio_channels = devm_kcalloc(&st->spi->dev,
  525. chip_info->num_channels,
  526. sizeof(struct iio_chan_spec),
  527. GFP_KERNEL);
  528. if (!st->iio_channels)
  529. return -ENOMEM;
  530. for (i = 0; i < chip_info->num_channels; i++) {
  531. st->iio_channels[i] = ltc2664_channel_template;
  532. st->iio_channels[i].type = chip_info->measurement_type;
  533. st->iio_channels[i].channel = i;
  534. }
  535. ret = ltc2664_channel_config(st);
  536. if (ret)
  537. return ret;
  538. return regmap_set_bits(st->regmap, LTC2664_CMD_CONFIG, LTC2664_REF_DISABLE);
  539. }
  540. static const struct regmap_config ltc2664_regmap_config = {
  541. .reg_bits = 8,
  542. .val_bits = 16,
  543. .max_register = LTC2664_CMD_NO_OPERATION,
  544. };
  545. static const struct iio_info ltc2664_info = {
  546. .write_raw = ltc2664_write_raw,
  547. .read_raw = ltc2664_read_raw,
  548. .read_avail = ltc2664_read_avail,
  549. .debugfs_reg_access = ltc2664_reg_access,
  550. };
  551. static int ltc2664_probe(struct spi_device *spi)
  552. {
  553. static const char * const regulators[] = { "vcc", "iovcc", "v-neg" };
  554. const struct ltc2664_chip_info *chip_info;
  555. struct device *dev = &spi->dev;
  556. struct iio_dev *indio_dev;
  557. struct ltc2664_state *st;
  558. int ret;
  559. indio_dev = devm_iio_device_alloc(dev, sizeof(*st));
  560. if (!indio_dev)
  561. return -ENOMEM;
  562. st = iio_priv(indio_dev);
  563. st->spi = spi;
  564. chip_info = spi_get_device_match_data(spi);
  565. if (!chip_info)
  566. return -ENODEV;
  567. st->chip_info = chip_info;
  568. mutex_init(&st->lock);
  569. st->regmap = devm_regmap_init_spi(spi, &ltc2664_regmap_config);
  570. if (IS_ERR(st->regmap))
  571. return dev_err_probe(dev, PTR_ERR(st->regmap),
  572. "Failed to init regmap");
  573. ret = devm_regulator_bulk_get_enable(dev, ARRAY_SIZE(regulators),
  574. regulators);
  575. if (ret)
  576. return dev_err_probe(dev, ret, "Failed to enable regulators\n");
  577. ret = devm_regulator_get_enable_read_voltage(dev, "ref");
  578. if (ret < 0 && ret != -ENODEV)
  579. return ret;
  580. st->vref_mv = ret > 0 ? ret / 1000 : chip_info->internal_vref_mv;
  581. ret = ltc2664_setup(st);
  582. if (ret)
  583. return ret;
  584. indio_dev->name = chip_info->name;
  585. indio_dev->info = &ltc2664_info;
  586. indio_dev->modes = INDIO_DIRECT_MODE;
  587. indio_dev->channels = st->iio_channels;
  588. indio_dev->num_channels = chip_info->num_channels;
  589. return devm_iio_device_register(dev, indio_dev);
  590. }
  591. static const struct spi_device_id ltc2664_id[] = {
  592. { "ltc2664", (kernel_ulong_t)&ltc2664_chip },
  593. { "ltc2672", (kernel_ulong_t)&ltc2672_chip },
  594. { }
  595. };
  596. MODULE_DEVICE_TABLE(spi, ltc2664_id);
  597. static const struct of_device_id ltc2664_of_id[] = {
  598. { .compatible = "adi,ltc2664", .data = &ltc2664_chip },
  599. { .compatible = "adi,ltc2672", .data = &ltc2672_chip },
  600. { }
  601. };
  602. MODULE_DEVICE_TABLE(of, ltc2664_of_id);
  603. static struct spi_driver ltc2664_driver = {
  604. .driver = {
  605. .name = "ltc2664",
  606. .of_match_table = ltc2664_of_id,
  607. },
  608. .probe = ltc2664_probe,
  609. .id_table = ltc2664_id,
  610. };
  611. module_spi_driver(ltc2664_driver);
  612. MODULE_AUTHOR("Michael Hennerich <michael.hennerich@analog.com>");
  613. MODULE_AUTHOR("Kim Seer Paller <kimseer.paller@analog.com>");
  614. MODULE_DESCRIPTION("Analog Devices LTC2664 and LTC2672 DAC");
  615. MODULE_LICENSE("GPL");