at91_adc.c 20 KB

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  1. /*
  2. * Driver for the ADC present in the Atmel AT91 evaluation boards.
  3. *
  4. * Copyright 2011 Free Electrons
  5. *
  6. * Licensed under the GPLv2 or later.
  7. */
  8. #include <linux/bitmap.h>
  9. #include <linux/bitops.h>
  10. #include <linux/clk.h>
  11. #include <linux/err.h>
  12. #include <linux/io.h>
  13. #include <linux/interrupt.h>
  14. #include <linux/jiffies.h>
  15. #include <linux/kernel.h>
  16. #include <linux/module.h>
  17. #include <linux/of.h>
  18. #include <linux/of_device.h>
  19. #include <linux/platform_device.h>
  20. #include <linux/sched.h>
  21. #include <linux/slab.h>
  22. #include <linux/wait.h>
  23. #include <linux/platform_data/at91_adc.h>
  24. #include <linux/iio/iio.h>
  25. #include <linux/iio/buffer.h>
  26. #include <linux/iio/trigger.h>
  27. #include <linux/iio/trigger_consumer.h>
  28. #include <linux/iio/triggered_buffer.h>
  29. #include <mach/at91_adc.h>
  30. #define AT91_ADC_CHAN(st, ch) \
  31. (st->registers->channel_base + (ch * 4))
  32. #define at91_adc_readl(st, reg) \
  33. (readl_relaxed(st->reg_base + reg))
  34. #define at91_adc_writel(st, reg, val) \
  35. (writel_relaxed(val, st->reg_base + reg))
  36. struct at91_adc_caps {
  37. struct at91_adc_reg_desc registers;
  38. };
  39. struct at91_adc_state {
  40. struct clk *adc_clk;
  41. u16 *buffer;
  42. unsigned long channels_mask;
  43. struct clk *clk;
  44. bool done;
  45. int irq;
  46. u16 last_value;
  47. struct mutex lock;
  48. u8 num_channels;
  49. void __iomem *reg_base;
  50. struct at91_adc_reg_desc *registers;
  51. u8 startup_time;
  52. u8 sample_hold_time;
  53. bool sleep_mode;
  54. struct iio_trigger **trig;
  55. struct at91_adc_trigger *trigger_list;
  56. u32 trigger_number;
  57. bool use_external;
  58. u32 vref_mv;
  59. u32 res; /* resolution used for convertions */
  60. bool low_res; /* the resolution corresponds to the lowest one */
  61. wait_queue_head_t wq_data_avail;
  62. struct at91_adc_caps *caps;
  63. };
  64. static irqreturn_t at91_adc_trigger_handler(int irq, void *p)
  65. {
  66. struct iio_poll_func *pf = p;
  67. struct iio_dev *idev = pf->indio_dev;
  68. struct at91_adc_state *st = iio_priv(idev);
  69. int i, j = 0;
  70. for (i = 0; i < idev->masklength; i++) {
  71. if (!test_bit(i, idev->active_scan_mask))
  72. continue;
  73. st->buffer[j] = at91_adc_readl(st, AT91_ADC_CHAN(st, i));
  74. j++;
  75. }
  76. if (idev->scan_timestamp) {
  77. s64 *timestamp = (s64 *)((u8 *)st->buffer +
  78. ALIGN(j, sizeof(s64)));
  79. *timestamp = pf->timestamp;
  80. }
  81. iio_push_to_buffers(idev, (u8 *)st->buffer);
  82. iio_trigger_notify_done(idev->trig);
  83. /* Needed to ACK the DRDY interruption */
  84. at91_adc_readl(st, AT91_ADC_LCDR);
  85. enable_irq(st->irq);
  86. return IRQ_HANDLED;
  87. }
  88. static irqreturn_t at91_adc_eoc_trigger(int irq, void *private)
  89. {
  90. struct iio_dev *idev = private;
  91. struct at91_adc_state *st = iio_priv(idev);
  92. u32 status = at91_adc_readl(st, st->registers->status_register);
  93. if (!(status & st->registers->drdy_mask))
  94. return IRQ_HANDLED;
  95. if (iio_buffer_enabled(idev)) {
  96. disable_irq_nosync(irq);
  97. iio_trigger_poll(idev->trig, iio_get_time_ns());
  98. } else {
  99. st->last_value = at91_adc_readl(st, AT91_ADC_LCDR);
  100. st->done = true;
  101. wake_up_interruptible(&st->wq_data_avail);
  102. }
  103. return IRQ_HANDLED;
  104. }
  105. static int at91_adc_channel_init(struct iio_dev *idev)
  106. {
  107. struct at91_adc_state *st = iio_priv(idev);
  108. struct iio_chan_spec *chan_array, *timestamp;
  109. int bit, idx = 0;
  110. idev->num_channels = bitmap_weight(&st->channels_mask,
  111. st->num_channels) + 1;
  112. chan_array = devm_kzalloc(&idev->dev,
  113. ((idev->num_channels + 1) *
  114. sizeof(struct iio_chan_spec)),
  115. GFP_KERNEL);
  116. if (!chan_array)
  117. return -ENOMEM;
  118. for_each_set_bit(bit, &st->channels_mask, st->num_channels) {
  119. struct iio_chan_spec *chan = chan_array + idx;
  120. chan->type = IIO_VOLTAGE;
  121. chan->indexed = 1;
  122. chan->channel = bit;
  123. chan->scan_index = idx;
  124. chan->scan_type.sign = 'u';
  125. chan->scan_type.realbits = st->res;
  126. chan->scan_type.storagebits = 16;
  127. chan->info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE);
  128. chan->info_mask_separate = BIT(IIO_CHAN_INFO_RAW);
  129. idx++;
  130. }
  131. timestamp = chan_array + idx;
  132. timestamp->type = IIO_TIMESTAMP;
  133. timestamp->channel = -1;
  134. timestamp->scan_index = idx;
  135. timestamp->scan_type.sign = 's';
  136. timestamp->scan_type.realbits = 64;
  137. timestamp->scan_type.storagebits = 64;
  138. idev->channels = chan_array;
  139. return idev->num_channels;
  140. }
  141. static u8 at91_adc_get_trigger_value_by_name(struct iio_dev *idev,
  142. struct at91_adc_trigger *triggers,
  143. const char *trigger_name)
  144. {
  145. struct at91_adc_state *st = iio_priv(idev);
  146. u8 value = 0;
  147. int i;
  148. for (i = 0; i < st->trigger_number; i++) {
  149. char *name = kasprintf(GFP_KERNEL,
  150. "%s-dev%d-%s",
  151. idev->name,
  152. idev->id,
  153. triggers[i].name);
  154. if (!name)
  155. return -ENOMEM;
  156. if (strcmp(trigger_name, name) == 0) {
  157. value = triggers[i].value;
  158. kfree(name);
  159. break;
  160. }
  161. kfree(name);
  162. }
  163. return value;
  164. }
  165. static int at91_adc_configure_trigger(struct iio_trigger *trig, bool state)
  166. {
  167. struct iio_dev *idev = iio_trigger_get_drvdata(trig);
  168. struct at91_adc_state *st = iio_priv(idev);
  169. struct iio_buffer *buffer = idev->buffer;
  170. struct at91_adc_reg_desc *reg = st->registers;
  171. u32 status = at91_adc_readl(st, reg->trigger_register);
  172. u8 value;
  173. u8 bit;
  174. value = at91_adc_get_trigger_value_by_name(idev,
  175. st->trigger_list,
  176. idev->trig->name);
  177. if (value == 0)
  178. return -EINVAL;
  179. if (state) {
  180. st->buffer = kmalloc(idev->scan_bytes, GFP_KERNEL);
  181. if (st->buffer == NULL)
  182. return -ENOMEM;
  183. at91_adc_writel(st, reg->trigger_register,
  184. status | value);
  185. for_each_set_bit(bit, buffer->scan_mask,
  186. st->num_channels) {
  187. struct iio_chan_spec const *chan = idev->channels + bit;
  188. at91_adc_writel(st, AT91_ADC_CHER,
  189. AT91_ADC_CH(chan->channel));
  190. }
  191. at91_adc_writel(st, AT91_ADC_IER, reg->drdy_mask);
  192. } else {
  193. at91_adc_writel(st, AT91_ADC_IDR, reg->drdy_mask);
  194. at91_adc_writel(st, reg->trigger_register,
  195. status & ~value);
  196. for_each_set_bit(bit, buffer->scan_mask,
  197. st->num_channels) {
  198. struct iio_chan_spec const *chan = idev->channels + bit;
  199. at91_adc_writel(st, AT91_ADC_CHDR,
  200. AT91_ADC_CH(chan->channel));
  201. }
  202. kfree(st->buffer);
  203. }
  204. return 0;
  205. }
  206. static const struct iio_trigger_ops at91_adc_trigger_ops = {
  207. .owner = THIS_MODULE,
  208. .set_trigger_state = &at91_adc_configure_trigger,
  209. };
  210. static struct iio_trigger *at91_adc_allocate_trigger(struct iio_dev *idev,
  211. struct at91_adc_trigger *trigger)
  212. {
  213. struct iio_trigger *trig;
  214. int ret;
  215. trig = iio_trigger_alloc("%s-dev%d-%s", idev->name,
  216. idev->id, trigger->name);
  217. if (trig == NULL)
  218. return NULL;
  219. trig->dev.parent = idev->dev.parent;
  220. iio_trigger_set_drvdata(trig, idev);
  221. trig->ops = &at91_adc_trigger_ops;
  222. ret = iio_trigger_register(trig);
  223. if (ret)
  224. return NULL;
  225. return trig;
  226. }
  227. static int at91_adc_trigger_init(struct iio_dev *idev)
  228. {
  229. struct at91_adc_state *st = iio_priv(idev);
  230. int i, ret;
  231. st->trig = devm_kzalloc(&idev->dev,
  232. st->trigger_number * sizeof(st->trig),
  233. GFP_KERNEL);
  234. if (st->trig == NULL) {
  235. ret = -ENOMEM;
  236. goto error_ret;
  237. }
  238. for (i = 0; i < st->trigger_number; i++) {
  239. if (st->trigger_list[i].is_external && !(st->use_external))
  240. continue;
  241. st->trig[i] = at91_adc_allocate_trigger(idev,
  242. st->trigger_list + i);
  243. if (st->trig[i] == NULL) {
  244. dev_err(&idev->dev,
  245. "Could not allocate trigger %d\n", i);
  246. ret = -ENOMEM;
  247. goto error_trigger;
  248. }
  249. }
  250. return 0;
  251. error_trigger:
  252. for (i--; i >= 0; i--) {
  253. iio_trigger_unregister(st->trig[i]);
  254. iio_trigger_free(st->trig[i]);
  255. }
  256. error_ret:
  257. return ret;
  258. }
  259. static void at91_adc_trigger_remove(struct iio_dev *idev)
  260. {
  261. struct at91_adc_state *st = iio_priv(idev);
  262. int i;
  263. for (i = 0; i < st->trigger_number; i++) {
  264. iio_trigger_unregister(st->trig[i]);
  265. iio_trigger_free(st->trig[i]);
  266. }
  267. }
  268. static int at91_adc_buffer_init(struct iio_dev *idev)
  269. {
  270. return iio_triggered_buffer_setup(idev, &iio_pollfunc_store_time,
  271. &at91_adc_trigger_handler, NULL);
  272. }
  273. static void at91_adc_buffer_remove(struct iio_dev *idev)
  274. {
  275. iio_triggered_buffer_cleanup(idev);
  276. }
  277. static int at91_adc_read_raw(struct iio_dev *idev,
  278. struct iio_chan_spec const *chan,
  279. int *val, int *val2, long mask)
  280. {
  281. struct at91_adc_state *st = iio_priv(idev);
  282. int ret;
  283. switch (mask) {
  284. case IIO_CHAN_INFO_RAW:
  285. mutex_lock(&st->lock);
  286. at91_adc_writel(st, AT91_ADC_CHER,
  287. AT91_ADC_CH(chan->channel));
  288. at91_adc_writel(st, AT91_ADC_IER, st->registers->drdy_mask);
  289. at91_adc_writel(st, AT91_ADC_CR, AT91_ADC_START);
  290. ret = wait_event_interruptible_timeout(st->wq_data_avail,
  291. st->done,
  292. msecs_to_jiffies(1000));
  293. if (ret == 0)
  294. ret = -ETIMEDOUT;
  295. if (ret < 0) {
  296. mutex_unlock(&st->lock);
  297. return ret;
  298. }
  299. *val = st->last_value;
  300. at91_adc_writel(st, AT91_ADC_CHDR,
  301. AT91_ADC_CH(chan->channel));
  302. at91_adc_writel(st, AT91_ADC_IDR, st->registers->drdy_mask);
  303. st->last_value = 0;
  304. st->done = false;
  305. mutex_unlock(&st->lock);
  306. return IIO_VAL_INT;
  307. case IIO_CHAN_INFO_SCALE:
  308. *val = (st->vref_mv * 1000) >> chan->scan_type.realbits;
  309. *val2 = 0;
  310. return IIO_VAL_INT_PLUS_MICRO;
  311. default:
  312. break;
  313. }
  314. return -EINVAL;
  315. }
  316. static int at91_adc_of_get_resolution(struct at91_adc_state *st,
  317. struct platform_device *pdev)
  318. {
  319. struct iio_dev *idev = iio_priv_to_dev(st);
  320. struct device_node *np = pdev->dev.of_node;
  321. int count, i, ret = 0;
  322. char *res_name, *s;
  323. u32 *resolutions;
  324. count = of_property_count_strings(np, "atmel,adc-res-names");
  325. if (count < 2) {
  326. dev_err(&idev->dev, "You must specified at least two resolution names for "
  327. "adc-res-names property in the DT\n");
  328. return count;
  329. }
  330. resolutions = kmalloc(count * sizeof(*resolutions), GFP_KERNEL);
  331. if (!resolutions)
  332. return -ENOMEM;
  333. if (of_property_read_u32_array(np, "atmel,adc-res", resolutions, count)) {
  334. dev_err(&idev->dev, "Missing adc-res property in the DT.\n");
  335. ret = -ENODEV;
  336. goto ret;
  337. }
  338. if (of_property_read_string(np, "atmel,adc-use-res", (const char **)&res_name))
  339. res_name = "highres";
  340. for (i = 0; i < count; i++) {
  341. if (of_property_read_string_index(np, "atmel,adc-res-names", i, (const char **)&s))
  342. continue;
  343. if (strcmp(res_name, s))
  344. continue;
  345. st->res = resolutions[i];
  346. if (!strcmp(res_name, "lowres"))
  347. st->low_res = true;
  348. else
  349. st->low_res = false;
  350. dev_info(&idev->dev, "Resolution used: %u bits\n", st->res);
  351. goto ret;
  352. }
  353. dev_err(&idev->dev, "There is no resolution for %s\n", res_name);
  354. ret:
  355. kfree(resolutions);
  356. return ret;
  357. }
  358. static const struct of_device_id at91_adc_dt_ids[];
  359. static int at91_adc_probe_dt(struct at91_adc_state *st,
  360. struct platform_device *pdev)
  361. {
  362. struct iio_dev *idev = iio_priv_to_dev(st);
  363. struct device_node *node = pdev->dev.of_node;
  364. struct device_node *trig_node;
  365. int i = 0, ret;
  366. u32 prop;
  367. if (!node)
  368. return -EINVAL;
  369. st->caps = (struct at91_adc_caps *)
  370. of_match_device(at91_adc_dt_ids, &pdev->dev)->data;
  371. st->use_external = of_property_read_bool(node, "atmel,adc-use-external-triggers");
  372. if (of_property_read_u32(node, "atmel,adc-channels-used", &prop)) {
  373. dev_err(&idev->dev, "Missing adc-channels-used property in the DT.\n");
  374. ret = -EINVAL;
  375. goto error_ret;
  376. }
  377. st->channels_mask = prop;
  378. if (of_property_read_u32(node, "atmel,adc-num-channels", &prop)) {
  379. dev_err(&idev->dev, "Missing adc-num-channels property in the DT.\n");
  380. ret = -EINVAL;
  381. goto error_ret;
  382. }
  383. st->num_channels = prop;
  384. st->sleep_mode = of_property_read_bool(node, "atmel,adc-sleep-mode");
  385. if (of_property_read_u32(node, "atmel,adc-startup-time", &prop)) {
  386. dev_err(&idev->dev, "Missing adc-startup-time property in the DT.\n");
  387. ret = -EINVAL;
  388. goto error_ret;
  389. }
  390. st->startup_time = prop;
  391. prop = 0;
  392. of_property_read_u32(node, "atmel,adc-sample-hold-time", &prop);
  393. st->sample_hold_time = prop;
  394. if (of_property_read_u32(node, "atmel,adc-vref", &prop)) {
  395. dev_err(&idev->dev, "Missing adc-vref property in the DT.\n");
  396. ret = -EINVAL;
  397. goto error_ret;
  398. }
  399. st->vref_mv = prop;
  400. ret = at91_adc_of_get_resolution(st, pdev);
  401. if (ret)
  402. goto error_ret;
  403. st->registers = &st->caps->registers;
  404. st->trigger_number = of_get_child_count(node);
  405. st->trigger_list = devm_kzalloc(&idev->dev, st->trigger_number *
  406. sizeof(struct at91_adc_trigger),
  407. GFP_KERNEL);
  408. if (!st->trigger_list) {
  409. dev_err(&idev->dev, "Could not allocate trigger list memory.\n");
  410. ret = -ENOMEM;
  411. goto error_ret;
  412. }
  413. for_each_child_of_node(node, trig_node) {
  414. struct at91_adc_trigger *trig = st->trigger_list + i;
  415. const char *name;
  416. if (of_property_read_string(trig_node, "trigger-name", &name)) {
  417. dev_err(&idev->dev, "Missing trigger-name property in the DT.\n");
  418. ret = -EINVAL;
  419. goto error_ret;
  420. }
  421. trig->name = name;
  422. if (of_property_read_u32(trig_node, "trigger-value", &prop)) {
  423. dev_err(&idev->dev, "Missing trigger-value property in the DT.\n");
  424. ret = -EINVAL;
  425. goto error_ret;
  426. }
  427. trig->value = prop;
  428. trig->is_external = of_property_read_bool(trig_node, "trigger-external");
  429. i++;
  430. }
  431. return 0;
  432. error_ret:
  433. return ret;
  434. }
  435. static int at91_adc_probe_pdata(struct at91_adc_state *st,
  436. struct platform_device *pdev)
  437. {
  438. struct at91_adc_data *pdata = pdev->dev.platform_data;
  439. if (!pdata)
  440. return -EINVAL;
  441. st->use_external = pdata->use_external_triggers;
  442. st->vref_mv = pdata->vref;
  443. st->channels_mask = pdata->channels_used;
  444. st->num_channels = pdata->num_channels;
  445. st->startup_time = pdata->startup_time;
  446. st->trigger_number = pdata->trigger_number;
  447. st->trigger_list = pdata->trigger_list;
  448. st->registers = pdata->registers;
  449. return 0;
  450. }
  451. static const struct iio_info at91_adc_info = {
  452. .driver_module = THIS_MODULE,
  453. .read_raw = &at91_adc_read_raw,
  454. };
  455. static int at91_adc_probe(struct platform_device *pdev)
  456. {
  457. unsigned int prsc, mstrclk, ticks, adc_clk, adc_clk_khz, shtim;
  458. int ret;
  459. struct iio_dev *idev;
  460. struct at91_adc_state *st;
  461. struct resource *res;
  462. u32 reg;
  463. idev = devm_iio_device_alloc(&pdev->dev, sizeof(struct at91_adc_state));
  464. if (!idev)
  465. return -ENOMEM;
  466. st = iio_priv(idev);
  467. if (pdev->dev.of_node)
  468. ret = at91_adc_probe_dt(st, pdev);
  469. else
  470. ret = at91_adc_probe_pdata(st, pdev);
  471. if (ret) {
  472. dev_err(&pdev->dev, "No platform data available.\n");
  473. return -EINVAL;
  474. }
  475. platform_set_drvdata(pdev, idev);
  476. idev->dev.parent = &pdev->dev;
  477. idev->name = dev_name(&pdev->dev);
  478. idev->modes = INDIO_DIRECT_MODE;
  479. idev->info = &at91_adc_info;
  480. st->irq = platform_get_irq(pdev, 0);
  481. if (st->irq < 0) {
  482. dev_err(&pdev->dev, "No IRQ ID is designated\n");
  483. return -ENODEV;
  484. }
  485. res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
  486. st->reg_base = devm_ioremap_resource(&pdev->dev, res);
  487. if (IS_ERR(st->reg_base)) {
  488. return PTR_ERR(st->reg_base);
  489. }
  490. /*
  491. * Disable all IRQs before setting up the handler
  492. */
  493. at91_adc_writel(st, AT91_ADC_CR, AT91_ADC_SWRST);
  494. at91_adc_writel(st, AT91_ADC_IDR, 0xFFFFFFFF);
  495. ret = request_irq(st->irq,
  496. at91_adc_eoc_trigger,
  497. 0,
  498. pdev->dev.driver->name,
  499. idev);
  500. if (ret) {
  501. dev_err(&pdev->dev, "Failed to allocate IRQ.\n");
  502. return ret;
  503. }
  504. st->clk = devm_clk_get(&pdev->dev, "adc_clk");
  505. if (IS_ERR(st->clk)) {
  506. dev_err(&pdev->dev, "Failed to get the clock.\n");
  507. ret = PTR_ERR(st->clk);
  508. goto error_free_irq;
  509. }
  510. ret = clk_prepare_enable(st->clk);
  511. if (ret) {
  512. dev_err(&pdev->dev,
  513. "Could not prepare or enable the clock.\n");
  514. goto error_free_irq;
  515. }
  516. st->adc_clk = devm_clk_get(&pdev->dev, "adc_op_clk");
  517. if (IS_ERR(st->adc_clk)) {
  518. dev_err(&pdev->dev, "Failed to get the ADC clock.\n");
  519. ret = PTR_ERR(st->adc_clk);
  520. goto error_disable_clk;
  521. }
  522. ret = clk_prepare_enable(st->adc_clk);
  523. if (ret) {
  524. dev_err(&pdev->dev,
  525. "Could not prepare or enable the ADC clock.\n");
  526. goto error_disable_clk;
  527. }
  528. /*
  529. * Prescaler rate computation using the formula from the Atmel's
  530. * datasheet : ADC Clock = MCK / ((Prescaler + 1) * 2), ADC Clock being
  531. * specified by the electrical characteristics of the board.
  532. */
  533. mstrclk = clk_get_rate(st->clk);
  534. adc_clk = clk_get_rate(st->adc_clk);
  535. adc_clk_khz = adc_clk / 1000;
  536. prsc = (mstrclk / (2 * adc_clk)) - 1;
  537. if (!st->startup_time) {
  538. dev_err(&pdev->dev, "No startup time available.\n");
  539. ret = -EINVAL;
  540. goto error_disable_adc_clk;
  541. }
  542. /*
  543. * Number of ticks needed to cover the startup time of the ADC as
  544. * defined in the electrical characteristics of the board, divided by 8.
  545. * The formula thus is : Startup Time = (ticks + 1) * 8 / ADC Clock
  546. */
  547. ticks = round_up((st->startup_time * adc_clk_khz /
  548. 1000) - 1, 8) / 8;
  549. /*
  550. * a minimal Sample and Hold Time is necessary for the ADC to guarantee
  551. * the best converted final value between two channels selection
  552. * The formula thus is : Sample and Hold Time = (shtim + 1) / ADCClock
  553. */
  554. shtim = round_up((st->sample_hold_time * adc_clk_khz /
  555. 1000) - 1, 1);
  556. reg = AT91_ADC_PRESCAL_(prsc) & st->registers->mr_prescal_mask;
  557. reg |= AT91_ADC_STARTUP_(ticks) & st->registers->mr_startup_mask;
  558. if (st->low_res)
  559. reg |= AT91_ADC_LOWRES;
  560. if (st->sleep_mode)
  561. reg |= AT91_ADC_SLEEP;
  562. reg |= AT91_ADC_SHTIM_(shtim) & AT91_ADC_SHTIM;
  563. at91_adc_writel(st, AT91_ADC_MR, reg);
  564. /* Setup the ADC channels available on the board */
  565. ret = at91_adc_channel_init(idev);
  566. if (ret < 0) {
  567. dev_err(&pdev->dev, "Couldn't initialize the channels.\n");
  568. goto error_disable_adc_clk;
  569. }
  570. init_waitqueue_head(&st->wq_data_avail);
  571. mutex_init(&st->lock);
  572. ret = at91_adc_buffer_init(idev);
  573. if (ret < 0) {
  574. dev_err(&pdev->dev, "Couldn't initialize the buffer.\n");
  575. goto error_disable_adc_clk;
  576. }
  577. ret = at91_adc_trigger_init(idev);
  578. if (ret < 0) {
  579. dev_err(&pdev->dev, "Couldn't setup the triggers.\n");
  580. goto error_unregister_buffer;
  581. }
  582. ret = iio_device_register(idev);
  583. if (ret < 0) {
  584. dev_err(&pdev->dev, "Couldn't register the device.\n");
  585. goto error_remove_triggers;
  586. }
  587. return 0;
  588. error_remove_triggers:
  589. at91_adc_trigger_remove(idev);
  590. error_unregister_buffer:
  591. at91_adc_buffer_remove(idev);
  592. error_disable_adc_clk:
  593. clk_disable_unprepare(st->adc_clk);
  594. error_disable_clk:
  595. clk_disable_unprepare(st->clk);
  596. error_free_irq:
  597. free_irq(st->irq, idev);
  598. return ret;
  599. }
  600. static int at91_adc_remove(struct platform_device *pdev)
  601. {
  602. struct iio_dev *idev = platform_get_drvdata(pdev);
  603. struct at91_adc_state *st = iio_priv(idev);
  604. iio_device_unregister(idev);
  605. at91_adc_trigger_remove(idev);
  606. at91_adc_buffer_remove(idev);
  607. clk_disable_unprepare(st->adc_clk);
  608. clk_disable_unprepare(st->clk);
  609. free_irq(st->irq, idev);
  610. return 0;
  611. }
  612. #ifdef CONFIG_OF
  613. static struct at91_adc_caps at91sam9260_caps = {
  614. .registers = {
  615. .channel_base = AT91_ADC_CHR(0),
  616. .drdy_mask = AT91_ADC_DRDY,
  617. .status_register = AT91_ADC_SR,
  618. .trigger_register = AT91_ADC_TRGR_9260,
  619. .mr_prescal_mask = AT91_ADC_PRESCAL_9260,
  620. .mr_startup_mask = AT91_ADC_STARTUP_9260,
  621. },
  622. };
  623. static struct at91_adc_caps at91sam9g45_caps = {
  624. .registers = {
  625. .channel_base = AT91_ADC_CHR(0),
  626. .drdy_mask = AT91_ADC_DRDY,
  627. .status_register = AT91_ADC_SR,
  628. .trigger_register = AT91_ADC_TRGR_9G45,
  629. .mr_prescal_mask = AT91_ADC_PRESCAL_9G45,
  630. .mr_startup_mask = AT91_ADC_STARTUP_9G45,
  631. },
  632. };
  633. static struct at91_adc_caps at91sam9x5_caps = {
  634. .registers = {
  635. .channel_base = AT91_ADC_CDR0_9X5,
  636. .drdy_mask = AT91_ADC_SR_DRDY_9X5,
  637. .status_register = AT91_ADC_SR_9X5,
  638. .trigger_register = AT91_ADC_TRGR_9X5,
  639. /* prescal mask is same as 9G45 */
  640. .mr_prescal_mask = AT91_ADC_PRESCAL_9G45,
  641. .mr_startup_mask = AT91_ADC_STARTUP_9X5,
  642. },
  643. };
  644. static const struct of_device_id at91_adc_dt_ids[] = {
  645. { .compatible = "atmel,at91sam9260-adc", .data = &at91sam9260_caps },
  646. { .compatible = "atmel,at91sam9g45-adc", .data = &at91sam9g45_caps },
  647. { .compatible = "atmel,at91sam9x5-adc", .data = &at91sam9x5_caps },
  648. {},
  649. };
  650. MODULE_DEVICE_TABLE(of, at91_adc_dt_ids);
  651. #endif
  652. static struct platform_driver at91_adc_driver = {
  653. .probe = at91_adc_probe,
  654. .remove = at91_adc_remove,
  655. .driver = {
  656. .name = "at91_adc",
  657. .of_match_table = of_match_ptr(at91_adc_dt_ids),
  658. },
  659. };
  660. module_platform_driver(at91_adc_driver);
  661. MODULE_LICENSE("GPL");
  662. MODULE_DESCRIPTION("Atmel AT91 ADC Driver");
  663. MODULE_AUTHOR("Maxime Ripard <maxime.ripard@free-electrons.com>");