kxtj9.c 13 KB

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  1. // SPDX-License-Identifier: GPL-2.0-only
  2. /*
  3. * Copyright (C) 2011 Kionix, Inc.
  4. * Written by Chris Hudson <[email protected]>
  5. */
  6. #include <linux/delay.h>
  7. #include <linux/i2c.h>
  8. #include <linux/input.h>
  9. #include <linux/interrupt.h>
  10. #include <linux/module.h>
  11. #include <linux/slab.h>
  12. #include <linux/input/kxtj9.h>
  13. #define NAME "kxtj9"
  14. #define G_MAX 8000
  15. /* OUTPUT REGISTERS */
  16. #define XOUT_L 0x06
  17. #define WHO_AM_I 0x0F
  18. /* CONTROL REGISTERS */
  19. #define INT_REL 0x1A
  20. #define CTRL_REG1 0x1B
  21. #define INT_CTRL1 0x1E
  22. #define DATA_CTRL 0x21
  23. /* CONTROL REGISTER 1 BITS */
  24. #define PC1_OFF 0x7F
  25. #define PC1_ON (1 << 7)
  26. /* Data ready funtion enable bit: set during probe if using irq mode */
  27. #define DRDYE (1 << 5)
  28. /* DATA CONTROL REGISTER BITS */
  29. #define ODR12_5F 0
  30. #define ODR25F 1
  31. #define ODR50F 2
  32. #define ODR100F 3
  33. #define ODR200F 4
  34. #define ODR400F 5
  35. #define ODR800F 6
  36. /* INTERRUPT CONTROL REGISTER 1 BITS */
  37. /* Set these during probe if using irq mode */
  38. #define KXTJ9_IEL (1 << 3)
  39. #define KXTJ9_IEA (1 << 4)
  40. #define KXTJ9_IEN (1 << 5)
  41. /* INPUT_ABS CONSTANTS */
  42. #define FUZZ 3
  43. #define FLAT 3
  44. /* RESUME STATE INDICES */
  45. #define RES_DATA_CTRL 0
  46. #define RES_CTRL_REG1 1
  47. #define RES_INT_CTRL1 2
  48. #define RESUME_ENTRIES 3
  49. /*
  50. * The following table lists the maximum appropriate poll interval for each
  51. * available output data rate.
  52. */
  53. static const struct {
  54. unsigned int cutoff;
  55. u8 mask;
  56. } kxtj9_odr_table[] = {
  57. { 3, ODR800F },
  58. { 5, ODR400F },
  59. { 10, ODR200F },
  60. { 20, ODR100F },
  61. { 40, ODR50F },
  62. { 80, ODR25F },
  63. { 0, ODR12_5F},
  64. };
  65. struct kxtj9_data {
  66. struct i2c_client *client;
  67. struct kxtj9_platform_data pdata;
  68. struct input_dev *input_dev;
  69. unsigned int last_poll_interval;
  70. u8 shift;
  71. u8 ctrl_reg1;
  72. u8 data_ctrl;
  73. u8 int_ctrl;
  74. };
  75. static int kxtj9_i2c_read(struct kxtj9_data *tj9, u8 addr, u8 *data, int len)
  76. {
  77. struct i2c_msg msgs[] = {
  78. {
  79. .addr = tj9->client->addr,
  80. .flags = tj9->client->flags,
  81. .len = 1,
  82. .buf = &addr,
  83. },
  84. {
  85. .addr = tj9->client->addr,
  86. .flags = tj9->client->flags | I2C_M_RD,
  87. .len = len,
  88. .buf = data,
  89. },
  90. };
  91. return i2c_transfer(tj9->client->adapter, msgs, 2);
  92. }
  93. static void kxtj9_report_acceleration_data(struct kxtj9_data *tj9)
  94. {
  95. s16 acc_data[3]; /* Data bytes from hardware xL, xH, yL, yH, zL, zH */
  96. s16 x, y, z;
  97. int err;
  98. err = kxtj9_i2c_read(tj9, XOUT_L, (u8 *)acc_data, 6);
  99. if (err < 0)
  100. dev_err(&tj9->client->dev, "accelerometer data read failed\n");
  101. x = le16_to_cpu(acc_data[tj9->pdata.axis_map_x]);
  102. y = le16_to_cpu(acc_data[tj9->pdata.axis_map_y]);
  103. z = le16_to_cpu(acc_data[tj9->pdata.axis_map_z]);
  104. x >>= tj9->shift;
  105. y >>= tj9->shift;
  106. z >>= tj9->shift;
  107. input_report_abs(tj9->input_dev, ABS_X, tj9->pdata.negate_x ? -x : x);
  108. input_report_abs(tj9->input_dev, ABS_Y, tj9->pdata.negate_y ? -y : y);
  109. input_report_abs(tj9->input_dev, ABS_Z, tj9->pdata.negate_z ? -z : z);
  110. input_sync(tj9->input_dev);
  111. }
  112. static irqreturn_t kxtj9_isr(int irq, void *dev)
  113. {
  114. struct kxtj9_data *tj9 = dev;
  115. int err;
  116. /* data ready is the only possible interrupt type */
  117. kxtj9_report_acceleration_data(tj9);
  118. err = i2c_smbus_read_byte_data(tj9->client, INT_REL);
  119. if (err < 0)
  120. dev_err(&tj9->client->dev,
  121. "error clearing interrupt status: %d\n", err);
  122. return IRQ_HANDLED;
  123. }
  124. static int kxtj9_update_g_range(struct kxtj9_data *tj9, u8 new_g_range)
  125. {
  126. switch (new_g_range) {
  127. case KXTJ9_G_2G:
  128. tj9->shift = 4;
  129. break;
  130. case KXTJ9_G_4G:
  131. tj9->shift = 3;
  132. break;
  133. case KXTJ9_G_8G:
  134. tj9->shift = 2;
  135. break;
  136. default:
  137. return -EINVAL;
  138. }
  139. tj9->ctrl_reg1 &= 0xe7;
  140. tj9->ctrl_reg1 |= new_g_range;
  141. return 0;
  142. }
  143. static int kxtj9_update_odr(struct kxtj9_data *tj9, unsigned int poll_interval)
  144. {
  145. int err;
  146. int i;
  147. /* Use the lowest ODR that can support the requested poll interval */
  148. for (i = 0; i < ARRAY_SIZE(kxtj9_odr_table); i++) {
  149. tj9->data_ctrl = kxtj9_odr_table[i].mask;
  150. if (poll_interval < kxtj9_odr_table[i].cutoff)
  151. break;
  152. }
  153. err = i2c_smbus_write_byte_data(tj9->client, CTRL_REG1, 0);
  154. if (err < 0)
  155. return err;
  156. err = i2c_smbus_write_byte_data(tj9->client, DATA_CTRL, tj9->data_ctrl);
  157. if (err < 0)
  158. return err;
  159. err = i2c_smbus_write_byte_data(tj9->client, CTRL_REG1, tj9->ctrl_reg1);
  160. if (err < 0)
  161. return err;
  162. return 0;
  163. }
  164. static int kxtj9_device_power_on(struct kxtj9_data *tj9)
  165. {
  166. if (tj9->pdata.power_on)
  167. return tj9->pdata.power_on();
  168. return 0;
  169. }
  170. static void kxtj9_device_power_off(struct kxtj9_data *tj9)
  171. {
  172. int err;
  173. tj9->ctrl_reg1 &= PC1_OFF;
  174. err = i2c_smbus_write_byte_data(tj9->client, CTRL_REG1, tj9->ctrl_reg1);
  175. if (err < 0)
  176. dev_err(&tj9->client->dev, "soft power off failed\n");
  177. if (tj9->pdata.power_off)
  178. tj9->pdata.power_off();
  179. }
  180. static int kxtj9_enable(struct kxtj9_data *tj9)
  181. {
  182. int err;
  183. err = kxtj9_device_power_on(tj9);
  184. if (err < 0)
  185. return err;
  186. /* ensure that PC1 is cleared before updating control registers */
  187. err = i2c_smbus_write_byte_data(tj9->client, CTRL_REG1, 0);
  188. if (err < 0)
  189. return err;
  190. /* only write INT_CTRL_REG1 if in irq mode */
  191. if (tj9->client->irq) {
  192. err = i2c_smbus_write_byte_data(tj9->client,
  193. INT_CTRL1, tj9->int_ctrl);
  194. if (err < 0)
  195. return err;
  196. }
  197. err = kxtj9_update_g_range(tj9, tj9->pdata.g_range);
  198. if (err < 0)
  199. return err;
  200. /* turn on outputs */
  201. tj9->ctrl_reg1 |= PC1_ON;
  202. err = i2c_smbus_write_byte_data(tj9->client, CTRL_REG1, tj9->ctrl_reg1);
  203. if (err < 0)
  204. return err;
  205. err = kxtj9_update_odr(tj9, tj9->last_poll_interval);
  206. if (err < 0)
  207. return err;
  208. /* clear initial interrupt if in irq mode */
  209. if (tj9->client->irq) {
  210. err = i2c_smbus_read_byte_data(tj9->client, INT_REL);
  211. if (err < 0) {
  212. dev_err(&tj9->client->dev,
  213. "error clearing interrupt: %d\n", err);
  214. goto fail;
  215. }
  216. }
  217. return 0;
  218. fail:
  219. kxtj9_device_power_off(tj9);
  220. return err;
  221. }
  222. static void kxtj9_disable(struct kxtj9_data *tj9)
  223. {
  224. kxtj9_device_power_off(tj9);
  225. }
  226. static int kxtj9_input_open(struct input_dev *input)
  227. {
  228. struct kxtj9_data *tj9 = input_get_drvdata(input);
  229. return kxtj9_enable(tj9);
  230. }
  231. static void kxtj9_input_close(struct input_dev *dev)
  232. {
  233. struct kxtj9_data *tj9 = input_get_drvdata(dev);
  234. kxtj9_disable(tj9);
  235. }
  236. /*
  237. * When IRQ mode is selected, we need to provide an interface to allow the user
  238. * to change the output data rate of the part. For consistency, we are using
  239. * the set_poll method, which accepts a poll interval in milliseconds, and then
  240. * calls update_odr() while passing this value as an argument. In IRQ mode, the
  241. * data outputs will not be read AT the requested poll interval, rather, the
  242. * lowest ODR that can support the requested interval. The client application
  243. * will be responsible for retrieving data from the input node at the desired
  244. * interval.
  245. */
  246. /* Returns currently selected poll interval (in ms) */
  247. static ssize_t kxtj9_get_poll(struct device *dev,
  248. struct device_attribute *attr, char *buf)
  249. {
  250. struct i2c_client *client = to_i2c_client(dev);
  251. struct kxtj9_data *tj9 = i2c_get_clientdata(client);
  252. return sprintf(buf, "%d\n", tj9->last_poll_interval);
  253. }
  254. /* Allow users to select a new poll interval (in ms) */
  255. static ssize_t kxtj9_set_poll(struct device *dev, struct device_attribute *attr,
  256. const char *buf, size_t count)
  257. {
  258. struct i2c_client *client = to_i2c_client(dev);
  259. struct kxtj9_data *tj9 = i2c_get_clientdata(client);
  260. struct input_dev *input_dev = tj9->input_dev;
  261. unsigned int interval;
  262. int error;
  263. error = kstrtouint(buf, 10, &interval);
  264. if (error < 0)
  265. return error;
  266. /* Lock the device to prevent races with open/close (and itself) */
  267. mutex_lock(&input_dev->mutex);
  268. disable_irq(client->irq);
  269. /*
  270. * Set current interval to the greater of the minimum interval or
  271. * the requested interval
  272. */
  273. tj9->last_poll_interval = max(interval, tj9->pdata.min_interval);
  274. kxtj9_update_odr(tj9, tj9->last_poll_interval);
  275. enable_irq(client->irq);
  276. mutex_unlock(&input_dev->mutex);
  277. return count;
  278. }
  279. static DEVICE_ATTR(poll, S_IRUGO|S_IWUSR, kxtj9_get_poll, kxtj9_set_poll);
  280. static struct attribute *kxtj9_attributes[] = {
  281. &dev_attr_poll.attr,
  282. NULL
  283. };
  284. static struct attribute_group kxtj9_attribute_group = {
  285. .attrs = kxtj9_attributes
  286. };
  287. static void kxtj9_poll(struct input_dev *input)
  288. {
  289. struct kxtj9_data *tj9 = input_get_drvdata(input);
  290. unsigned int poll_interval = input_get_poll_interval(input);
  291. kxtj9_report_acceleration_data(tj9);
  292. if (poll_interval != tj9->last_poll_interval) {
  293. kxtj9_update_odr(tj9, poll_interval);
  294. tj9->last_poll_interval = poll_interval;
  295. }
  296. }
  297. static void kxtj9_platform_exit(void *data)
  298. {
  299. struct kxtj9_data *tj9 = data;
  300. if (tj9->pdata.exit)
  301. tj9->pdata.exit();
  302. }
  303. static int kxtj9_verify(struct kxtj9_data *tj9)
  304. {
  305. int retval;
  306. retval = kxtj9_device_power_on(tj9);
  307. if (retval < 0)
  308. return retval;
  309. retval = i2c_smbus_read_byte_data(tj9->client, WHO_AM_I);
  310. if (retval < 0) {
  311. dev_err(&tj9->client->dev, "read err int source\n");
  312. goto out;
  313. }
  314. retval = (retval != 0x07 && retval != 0x08) ? -EIO : 0;
  315. out:
  316. kxtj9_device_power_off(tj9);
  317. return retval;
  318. }
  319. static int kxtj9_probe(struct i2c_client *client,
  320. const struct i2c_device_id *id)
  321. {
  322. const struct kxtj9_platform_data *pdata =
  323. dev_get_platdata(&client->dev);
  324. struct kxtj9_data *tj9;
  325. struct input_dev *input_dev;
  326. int err;
  327. if (!i2c_check_functionality(client->adapter,
  328. I2C_FUNC_I2C | I2C_FUNC_SMBUS_BYTE_DATA)) {
  329. dev_err(&client->dev, "client is not i2c capable\n");
  330. return -ENXIO;
  331. }
  332. if (!pdata) {
  333. dev_err(&client->dev, "platform data is NULL; exiting\n");
  334. return -EINVAL;
  335. }
  336. tj9 = devm_kzalloc(&client->dev, sizeof(*tj9), GFP_KERNEL);
  337. if (!tj9) {
  338. dev_err(&client->dev,
  339. "failed to allocate memory for module data\n");
  340. return -ENOMEM;
  341. }
  342. tj9->client = client;
  343. tj9->pdata = *pdata;
  344. if (pdata->init) {
  345. err = pdata->init();
  346. if (err < 0)
  347. return err;
  348. }
  349. err = devm_add_action_or_reset(&client->dev, kxtj9_platform_exit, tj9);
  350. if (err)
  351. return err;
  352. err = kxtj9_verify(tj9);
  353. if (err < 0) {
  354. dev_err(&client->dev, "device not recognized\n");
  355. return err;
  356. }
  357. i2c_set_clientdata(client, tj9);
  358. tj9->ctrl_reg1 = tj9->pdata.res_12bit | tj9->pdata.g_range;
  359. tj9->last_poll_interval = tj9->pdata.init_interval;
  360. input_dev = devm_input_allocate_device(&client->dev);
  361. if (!input_dev) {
  362. dev_err(&client->dev, "input device allocate failed\n");
  363. return -ENOMEM;
  364. }
  365. input_set_drvdata(input_dev, tj9);
  366. tj9->input_dev = input_dev;
  367. input_dev->name = "kxtj9_accel";
  368. input_dev->id.bustype = BUS_I2C;
  369. input_dev->open = kxtj9_input_open;
  370. input_dev->close = kxtj9_input_close;
  371. input_set_abs_params(input_dev, ABS_X, -G_MAX, G_MAX, FUZZ, FLAT);
  372. input_set_abs_params(input_dev, ABS_Y, -G_MAX, G_MAX, FUZZ, FLAT);
  373. input_set_abs_params(input_dev, ABS_Z, -G_MAX, G_MAX, FUZZ, FLAT);
  374. if (client->irq <= 0) {
  375. err = input_setup_polling(input_dev, kxtj9_poll);
  376. if (err)
  377. return err;
  378. }
  379. err = input_register_device(input_dev);
  380. if (err) {
  381. dev_err(&client->dev,
  382. "unable to register input polled device %s: %d\n",
  383. input_dev->name, err);
  384. return err;
  385. }
  386. if (client->irq) {
  387. /* If in irq mode, populate INT_CTRL_REG1 and enable DRDY. */
  388. tj9->int_ctrl |= KXTJ9_IEN | KXTJ9_IEA | KXTJ9_IEL;
  389. tj9->ctrl_reg1 |= DRDYE;
  390. err = devm_request_threaded_irq(&client->dev, client->irq,
  391. NULL, kxtj9_isr,
  392. IRQF_TRIGGER_RISING |
  393. IRQF_ONESHOT,
  394. "kxtj9-irq", tj9);
  395. if (err) {
  396. dev_err(&client->dev, "request irq failed: %d\n", err);
  397. return err;
  398. }
  399. err = devm_device_add_group(&client->dev,
  400. &kxtj9_attribute_group);
  401. if (err) {
  402. dev_err(&client->dev, "sysfs create failed: %d\n", err);
  403. return err;
  404. }
  405. }
  406. return 0;
  407. }
  408. static int __maybe_unused kxtj9_suspend(struct device *dev)
  409. {
  410. struct i2c_client *client = to_i2c_client(dev);
  411. struct kxtj9_data *tj9 = i2c_get_clientdata(client);
  412. struct input_dev *input_dev = tj9->input_dev;
  413. mutex_lock(&input_dev->mutex);
  414. if (input_device_enabled(input_dev))
  415. kxtj9_disable(tj9);
  416. mutex_unlock(&input_dev->mutex);
  417. return 0;
  418. }
  419. static int __maybe_unused kxtj9_resume(struct device *dev)
  420. {
  421. struct i2c_client *client = to_i2c_client(dev);
  422. struct kxtj9_data *tj9 = i2c_get_clientdata(client);
  423. struct input_dev *input_dev = tj9->input_dev;
  424. mutex_lock(&input_dev->mutex);
  425. if (input_device_enabled(input_dev))
  426. kxtj9_enable(tj9);
  427. mutex_unlock(&input_dev->mutex);
  428. return 0;
  429. }
  430. static SIMPLE_DEV_PM_OPS(kxtj9_pm_ops, kxtj9_suspend, kxtj9_resume);
  431. static const struct i2c_device_id kxtj9_id[] = {
  432. { NAME, 0 },
  433. { },
  434. };
  435. MODULE_DEVICE_TABLE(i2c, kxtj9_id);
  436. static struct i2c_driver kxtj9_driver = {
  437. .driver = {
  438. .name = NAME,
  439. .pm = &kxtj9_pm_ops,
  440. },
  441. .probe = kxtj9_probe,
  442. .id_table = kxtj9_id,
  443. };
  444. module_i2c_driver(kxtj9_driver);
  445. MODULE_DESCRIPTION("KXTJ9 accelerometer driver");
  446. MODULE_AUTHOR("Chris Hudson <[email protected]>");
  447. MODULE_LICENSE("GPL");