pulsedlight-lidar-lite-v2.c 8.4 KB

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  1. // SPDX-License-Identifier: GPL-2.0+
  2. /*
  3. * pulsedlight-lidar-lite-v2.c - Support for PulsedLight LIDAR sensor
  4. *
  5. * Copyright (C) 2015, 2017-2018
  6. * Author: Matt Ranostay <matt.ranostay@konsulko.com>
  7. *
  8. * TODO: interrupt mode, and signal strength reporting
  9. */
  10. #include <linux/err.h>
  11. #include <linux/init.h>
  12. #include <linux/i2c.h>
  13. #include <linux/delay.h>
  14. #include <linux/module.h>
  15. #include <linux/mod_devicetable.h>
  16. #include <linux/pm_runtime.h>
  17. #include <linux/iio/iio.h>
  18. #include <linux/iio/sysfs.h>
  19. #include <linux/iio/buffer.h>
  20. #include <linux/iio/trigger.h>
  21. #include <linux/iio/triggered_buffer.h>
  22. #include <linux/iio/trigger_consumer.h>
  23. #define LIDAR_REG_CONTROL 0x00
  24. #define LIDAR_REG_CONTROL_ACQUIRE BIT(2)
  25. #define LIDAR_REG_STATUS 0x01
  26. #define LIDAR_REG_STATUS_INVALID BIT(3)
  27. #define LIDAR_REG_STATUS_READY BIT(0)
  28. #define LIDAR_REG_DATA_HBYTE 0x0f
  29. #define LIDAR_REG_DATA_LBYTE 0x10
  30. #define LIDAR_REG_DATA_WORD_READ BIT(7)
  31. #define LIDAR_REG_PWR_CONTROL 0x65
  32. #define LIDAR_DRV_NAME "lidar"
  33. struct lidar_data {
  34. struct iio_dev *indio_dev;
  35. struct i2c_client *client;
  36. int (*xfer)(struct lidar_data *data, u8 reg, u8 *val, int len);
  37. int i2c_enabled;
  38. /* Ensure timestamp is naturally aligned */
  39. struct {
  40. u16 chan;
  41. s64 timestamp __aligned(8);
  42. } scan;
  43. };
  44. static const struct iio_chan_spec lidar_channels[] = {
  45. {
  46. .type = IIO_DISTANCE,
  47. .info_mask_separate =
  48. BIT(IIO_CHAN_INFO_RAW) | BIT(IIO_CHAN_INFO_SCALE),
  49. .scan_index = 0,
  50. .scan_type = {
  51. .sign = 'u',
  52. .realbits = 16,
  53. .storagebits = 16,
  54. },
  55. },
  56. IIO_CHAN_SOFT_TIMESTAMP(1),
  57. };
  58. static int lidar_i2c_xfer(struct lidar_data *data, u8 reg, u8 *val, int len)
  59. {
  60. struct i2c_client *client = data->client;
  61. struct i2c_msg msg[2];
  62. int ret;
  63. msg[0].addr = client->addr;
  64. msg[0].flags = client->flags | I2C_M_STOP;
  65. msg[0].len = 1;
  66. msg[0].buf = (char *) &reg;
  67. msg[1].addr = client->addr;
  68. msg[1].flags = client->flags | I2C_M_RD;
  69. msg[1].len = len;
  70. msg[1].buf = (char *) val;
  71. ret = i2c_transfer(client->adapter, msg, 2);
  72. return (ret == 2) ? 0 : -EIO;
  73. }
  74. static int lidar_smbus_xfer(struct lidar_data *data, u8 reg, u8 *val, int len)
  75. {
  76. struct i2c_client *client = data->client;
  77. int ret;
  78. /*
  79. * Device needs a STOP condition between address write, and data read
  80. * so in turn i2c_smbus_read_byte_data cannot be used
  81. */
  82. while (len--) {
  83. ret = i2c_smbus_write_byte(client, reg++);
  84. if (ret < 0) {
  85. dev_err(&client->dev, "cannot write addr value");
  86. return ret;
  87. }
  88. ret = i2c_smbus_read_byte(client);
  89. if (ret < 0) {
  90. dev_err(&client->dev, "cannot read data value");
  91. return ret;
  92. }
  93. *(val++) = ret;
  94. }
  95. return 0;
  96. }
  97. static int lidar_read_byte(struct lidar_data *data, u8 reg)
  98. {
  99. int ret;
  100. u8 val;
  101. ret = data->xfer(data, reg, &val, 1);
  102. if (ret < 0)
  103. return ret;
  104. return val;
  105. }
  106. static inline int lidar_write_control(struct lidar_data *data, int val)
  107. {
  108. return i2c_smbus_write_byte_data(data->client, LIDAR_REG_CONTROL, val);
  109. }
  110. static inline int lidar_write_power(struct lidar_data *data, int val)
  111. {
  112. return i2c_smbus_write_byte_data(data->client,
  113. LIDAR_REG_PWR_CONTROL, val);
  114. }
  115. static int lidar_read_measurement(struct lidar_data *data, u16 *reg)
  116. {
  117. __be16 value;
  118. int ret = data->xfer(data, LIDAR_REG_DATA_HBYTE |
  119. (data->i2c_enabled ? LIDAR_REG_DATA_WORD_READ : 0),
  120. (u8 *) &value, 2);
  121. if (!ret)
  122. *reg = be16_to_cpu(value);
  123. return ret;
  124. }
  125. static int lidar_get_measurement(struct lidar_data *data, u16 *reg)
  126. {
  127. struct i2c_client *client = data->client;
  128. int tries = 10;
  129. int ret;
  130. pm_runtime_get_sync(&client->dev);
  131. /* start sample */
  132. ret = lidar_write_control(data, LIDAR_REG_CONTROL_ACQUIRE);
  133. if (ret < 0) {
  134. dev_err(&client->dev, "cannot send start measurement command");
  135. pm_runtime_put_noidle(&client->dev);
  136. return ret;
  137. }
  138. while (tries--) {
  139. usleep_range(1000, 2000);
  140. ret = lidar_read_byte(data, LIDAR_REG_STATUS);
  141. if (ret < 0)
  142. break;
  143. /* return -EINVAL since laser is likely pointed out of range */
  144. if (ret & LIDAR_REG_STATUS_INVALID) {
  145. *reg = 0;
  146. ret = -EINVAL;
  147. break;
  148. }
  149. /* sample ready to read */
  150. if (!(ret & LIDAR_REG_STATUS_READY)) {
  151. ret = lidar_read_measurement(data, reg);
  152. break;
  153. }
  154. ret = -EIO;
  155. }
  156. pm_runtime_mark_last_busy(&client->dev);
  157. pm_runtime_put_autosuspend(&client->dev);
  158. return ret;
  159. }
  160. static int lidar_read_raw(struct iio_dev *indio_dev,
  161. struct iio_chan_spec const *chan,
  162. int *val, int *val2, long mask)
  163. {
  164. struct lidar_data *data = iio_priv(indio_dev);
  165. int ret = -EINVAL;
  166. switch (mask) {
  167. case IIO_CHAN_INFO_RAW: {
  168. u16 reg;
  169. if (iio_device_claim_direct_mode(indio_dev))
  170. return -EBUSY;
  171. ret = lidar_get_measurement(data, &reg);
  172. if (!ret) {
  173. *val = reg;
  174. ret = IIO_VAL_INT;
  175. }
  176. iio_device_release_direct_mode(indio_dev);
  177. break;
  178. }
  179. case IIO_CHAN_INFO_SCALE:
  180. *val = 0;
  181. *val2 = 10000;
  182. ret = IIO_VAL_INT_PLUS_MICRO;
  183. break;
  184. }
  185. return ret;
  186. }
  187. static irqreturn_t lidar_trigger_handler(int irq, void *private)
  188. {
  189. struct iio_poll_func *pf = private;
  190. struct iio_dev *indio_dev = pf->indio_dev;
  191. struct lidar_data *data = iio_priv(indio_dev);
  192. int ret;
  193. ret = lidar_get_measurement(data, &data->scan.chan);
  194. if (!ret) {
  195. iio_push_to_buffers_with_timestamp(indio_dev, &data->scan,
  196. iio_get_time_ns(indio_dev));
  197. } else if (ret != -EINVAL) {
  198. dev_err(&data->client->dev, "cannot read LIDAR measurement");
  199. }
  200. iio_trigger_notify_done(indio_dev->trig);
  201. return IRQ_HANDLED;
  202. }
  203. static const struct iio_info lidar_info = {
  204. .read_raw = lidar_read_raw,
  205. };
  206. static int lidar_probe(struct i2c_client *client,
  207. const struct i2c_device_id *id)
  208. {
  209. struct lidar_data *data;
  210. struct iio_dev *indio_dev;
  211. int ret;
  212. indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data));
  213. if (!indio_dev)
  214. return -ENOMEM;
  215. data = iio_priv(indio_dev);
  216. if (i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) {
  217. data->xfer = lidar_i2c_xfer;
  218. data->i2c_enabled = 1;
  219. } else if (i2c_check_functionality(client->adapter,
  220. I2C_FUNC_SMBUS_WORD_DATA | I2C_FUNC_SMBUS_BYTE))
  221. data->xfer = lidar_smbus_xfer;
  222. else
  223. return -EOPNOTSUPP;
  224. indio_dev->info = &lidar_info;
  225. indio_dev->name = LIDAR_DRV_NAME;
  226. indio_dev->channels = lidar_channels;
  227. indio_dev->num_channels = ARRAY_SIZE(lidar_channels);
  228. indio_dev->modes = INDIO_DIRECT_MODE;
  229. i2c_set_clientdata(client, indio_dev);
  230. data->client = client;
  231. data->indio_dev = indio_dev;
  232. ret = iio_triggered_buffer_setup(indio_dev, NULL,
  233. lidar_trigger_handler, NULL);
  234. if (ret)
  235. return ret;
  236. ret = iio_device_register(indio_dev);
  237. if (ret)
  238. goto error_unreg_buffer;
  239. pm_runtime_set_autosuspend_delay(&client->dev, 1000);
  240. pm_runtime_use_autosuspend(&client->dev);
  241. ret = pm_runtime_set_active(&client->dev);
  242. if (ret)
  243. goto error_unreg_buffer;
  244. pm_runtime_enable(&client->dev);
  245. pm_runtime_idle(&client->dev);
  246. return 0;
  247. error_unreg_buffer:
  248. iio_triggered_buffer_cleanup(indio_dev);
  249. return ret;
  250. }
  251. static int lidar_remove(struct i2c_client *client)
  252. {
  253. struct iio_dev *indio_dev = i2c_get_clientdata(client);
  254. iio_device_unregister(indio_dev);
  255. iio_triggered_buffer_cleanup(indio_dev);
  256. pm_runtime_disable(&client->dev);
  257. pm_runtime_set_suspended(&client->dev);
  258. return 0;
  259. }
  260. static const struct i2c_device_id lidar_id[] = {
  261. {"lidar-lite-v2", 0},
  262. {"lidar-lite-v3", 0},
  263. { },
  264. };
  265. MODULE_DEVICE_TABLE(i2c, lidar_id);
  266. static const struct of_device_id lidar_dt_ids[] = {
  267. { .compatible = "pulsedlight,lidar-lite-v2" },
  268. { .compatible = "grmn,lidar-lite-v3" },
  269. { }
  270. };
  271. MODULE_DEVICE_TABLE(of, lidar_dt_ids);
  272. #ifdef CONFIG_PM
  273. static int lidar_pm_runtime_suspend(struct device *dev)
  274. {
  275. struct iio_dev *indio_dev = i2c_get_clientdata(to_i2c_client(dev));
  276. struct lidar_data *data = iio_priv(indio_dev);
  277. return lidar_write_power(data, 0x0f);
  278. }
  279. static int lidar_pm_runtime_resume(struct device *dev)
  280. {
  281. struct iio_dev *indio_dev = i2c_get_clientdata(to_i2c_client(dev));
  282. struct lidar_data *data = iio_priv(indio_dev);
  283. int ret = lidar_write_power(data, 0);
  284. /* regulator and FPGA needs settling time */
  285. usleep_range(15000, 20000);
  286. return ret;
  287. }
  288. #endif
  289. static const struct dev_pm_ops lidar_pm_ops = {
  290. SET_RUNTIME_PM_OPS(lidar_pm_runtime_suspend,
  291. lidar_pm_runtime_resume, NULL)
  292. };
  293. static struct i2c_driver lidar_driver = {
  294. .driver = {
  295. .name = LIDAR_DRV_NAME,
  296. .of_match_table = lidar_dt_ids,
  297. .pm = &lidar_pm_ops,
  298. },
  299. .probe = lidar_probe,
  300. .remove = lidar_remove,
  301. .id_table = lidar_id,
  302. };
  303. module_i2c_driver(lidar_driver);
  304. MODULE_AUTHOR("Matt Ranostay <matt.ranostay@konsulko.com>");
  305. MODULE_DESCRIPTION("PulsedLight LIDAR sensor");
  306. MODULE_LICENSE("GPL");