1 /* 2 * pulsedlight-lidar-lite-v2.c - Support for PulsedLight LIDAR sensor 3 * 4 * Copyright (C) 2015 Matt Ranostay <mranostay@gmail.com> 5 * 6 * This program is free software; you can redistribute it and/or modify 7 * it under the terms of the GNU General Public License as published by 8 * the Free Software Foundation; either version 2 of the License, or 9 * (at your option) any later version. 10 * 11 * This program is distributed in the hope that it will be useful, 12 * but WITHOUT ANY WARRANTY; without even the implied warranty of 13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 14 * GNU General Public License for more details. 15 * 16 * TODO: interrupt mode, and signal strength reporting 17 */ 18 19 #include <linux/err.h> 20 #include <linux/init.h> 21 #include <linux/i2c.h> 22 #include <linux/delay.h> 23 #include <linux/module.h> 24 #include <linux/pm_runtime.h> 25 #include <linux/iio/iio.h> 26 #include <linux/iio/sysfs.h> 27 #include <linux/iio/buffer.h> 28 #include <linux/iio/trigger.h> 29 #include <linux/iio/triggered_buffer.h> 30 #include <linux/iio/trigger_consumer.h> 31 32 #define LIDAR_REG_CONTROL 0x00 33 #define LIDAR_REG_CONTROL_ACQUIRE BIT(2) 34 35 #define LIDAR_REG_STATUS 0x01 36 #define LIDAR_REG_STATUS_INVALID BIT(3) 37 #define LIDAR_REG_STATUS_READY BIT(0) 38 39 #define LIDAR_REG_DATA_HBYTE 0x0f 40 #define LIDAR_REG_DATA_LBYTE 0x10 41 #define LIDAR_REG_DATA_WORD_READ BIT(7) 42 43 #define LIDAR_REG_PWR_CONTROL 0x65 44 45 #define LIDAR_DRV_NAME "lidar" 46 47 struct lidar_data { 48 struct iio_dev *indio_dev; 49 struct i2c_client *client; 50 51 int (*xfer)(struct lidar_data *data, u8 reg, u8 *val, int len); 52 int i2c_enabled; 53 54 u16 buffer[8]; /* 2 byte distance + 8 byte timestamp */ 55 }; 56 57 static const struct iio_chan_spec lidar_channels[] = { 58 { 59 .type = IIO_DISTANCE, 60 .info_mask_separate = 61 BIT(IIO_CHAN_INFO_RAW) | BIT(IIO_CHAN_INFO_SCALE), 62 .scan_index = 0, 63 .scan_type = { 64 .sign = 'u', 65 .realbits = 16, 66 .storagebits = 16, 67 }, 68 }, 69 IIO_CHAN_SOFT_TIMESTAMP(1), 70 }; 71 72 static int lidar_i2c_xfer(struct lidar_data *data, u8 reg, u8 *val, int len) 73 { 74 struct i2c_client *client = data->client; 75 struct i2c_msg msg[2]; 76 int ret; 77 78 msg[0].addr = client->addr; 79 msg[0].flags = client->flags | I2C_M_STOP; 80 msg[0].len = 1; 81 msg[0].buf = (char *) ® 82 83 msg[1].addr = client->addr; 84 msg[1].flags = client->flags | I2C_M_RD; 85 msg[1].len = len; 86 msg[1].buf = (char *) val; 87 88 ret = i2c_transfer(client->adapter, msg, 2); 89 90 return (ret == 2) ? 0 : -EIO; 91 } 92 93 static int lidar_smbus_xfer(struct lidar_data *data, u8 reg, u8 *val, int len) 94 { 95 struct i2c_client *client = data->client; 96 int ret; 97 98 /* 99 * Device needs a STOP condition between address write, and data read 100 * so in turn i2c_smbus_read_byte_data cannot be used 101 */ 102 103 while (len--) { 104 ret = i2c_smbus_write_byte(client, reg++); 105 if (ret < 0) { 106 dev_err(&client->dev, "cannot write addr value"); 107 return ret; 108 } 109 110 ret = i2c_smbus_read_byte(client); 111 if (ret < 0) { 112 dev_err(&client->dev, "cannot read data value"); 113 return ret; 114 } 115 116 *(val++) = ret; 117 } 118 119 return 0; 120 } 121 122 static int lidar_read_byte(struct lidar_data *data, u8 reg) 123 { 124 int ret; 125 u8 val; 126 127 ret = data->xfer(data, reg, &val, 1); 128 if (ret < 0) 129 return ret; 130 131 return val; 132 } 133 134 static inline int lidar_write_control(struct lidar_data *data, int val) 135 { 136 return i2c_smbus_write_byte_data(data->client, LIDAR_REG_CONTROL, val); 137 } 138 139 static inline int lidar_write_power(struct lidar_data *data, int val) 140 { 141 return i2c_smbus_write_byte_data(data->client, 142 LIDAR_REG_PWR_CONTROL, val); 143 } 144 145 static int lidar_read_measurement(struct lidar_data *data, u16 *reg) 146 { 147 int ret = data->xfer(data, LIDAR_REG_DATA_HBYTE | 148 (data->i2c_enabled ? LIDAR_REG_DATA_WORD_READ : 0), 149 (u8 *) reg, 2); 150 151 if (!ret) 152 *reg = be16_to_cpu(*reg); 153 154 return ret; 155 } 156 157 static int lidar_get_measurement(struct lidar_data *data, u16 *reg) 158 { 159 struct i2c_client *client = data->client; 160 int tries = 10; 161 int ret; 162 163 pm_runtime_get_sync(&client->dev); 164 165 /* start sample */ 166 ret = lidar_write_control(data, LIDAR_REG_CONTROL_ACQUIRE); 167 if (ret < 0) { 168 dev_err(&client->dev, "cannot send start measurement command"); 169 return ret; 170 } 171 172 while (tries--) { 173 usleep_range(1000, 2000); 174 175 ret = lidar_read_byte(data, LIDAR_REG_STATUS); 176 if (ret < 0) 177 break; 178 179 /* return -EINVAL since laser is likely pointed out of range */ 180 if (ret & LIDAR_REG_STATUS_INVALID) { 181 *reg = 0; 182 ret = -EINVAL; 183 break; 184 } 185 186 /* sample ready to read */ 187 if (!(ret & LIDAR_REG_STATUS_READY)) { 188 ret = lidar_read_measurement(data, reg); 189 break; 190 } 191 ret = -EIO; 192 } 193 pm_runtime_mark_last_busy(&client->dev); 194 pm_runtime_put_autosuspend(&client->dev); 195 196 return ret; 197 } 198 199 static int lidar_read_raw(struct iio_dev *indio_dev, 200 struct iio_chan_spec const *chan, 201 int *val, int *val2, long mask) 202 { 203 struct lidar_data *data = iio_priv(indio_dev); 204 int ret = -EINVAL; 205 206 switch (mask) { 207 case IIO_CHAN_INFO_RAW: { 208 u16 reg; 209 210 if (iio_device_claim_direct_mode(indio_dev)) 211 return -EBUSY; 212 213 ret = lidar_get_measurement(data, ®); 214 if (!ret) { 215 *val = reg; 216 ret = IIO_VAL_INT; 217 } 218 iio_device_release_direct_mode(indio_dev); 219 break; 220 } 221 case IIO_CHAN_INFO_SCALE: 222 *val = 0; 223 *val2 = 10000; 224 ret = IIO_VAL_INT_PLUS_MICRO; 225 break; 226 } 227 228 return ret; 229 } 230 231 static irqreturn_t lidar_trigger_handler(int irq, void *private) 232 { 233 struct iio_poll_func *pf = private; 234 struct iio_dev *indio_dev = pf->indio_dev; 235 struct lidar_data *data = iio_priv(indio_dev); 236 int ret; 237 238 ret = lidar_get_measurement(data, data->buffer); 239 if (!ret) { 240 iio_push_to_buffers_with_timestamp(indio_dev, data->buffer, 241 iio_get_time_ns(indio_dev)); 242 } else if (ret != -EINVAL) { 243 dev_err(&data->client->dev, "cannot read LIDAR measurement"); 244 } 245 246 iio_trigger_notify_done(indio_dev->trig); 247 248 return IRQ_HANDLED; 249 } 250 251 static const struct iio_info lidar_info = { 252 .driver_module = THIS_MODULE, 253 .read_raw = lidar_read_raw, 254 }; 255 256 static int lidar_probe(struct i2c_client *client, 257 const struct i2c_device_id *id) 258 { 259 struct lidar_data *data; 260 struct iio_dev *indio_dev; 261 int ret; 262 263 indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data)); 264 if (!indio_dev) 265 return -ENOMEM; 266 data = iio_priv(indio_dev); 267 268 if (i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) { 269 data->xfer = lidar_i2c_xfer; 270 data->i2c_enabled = 1; 271 } else if (i2c_check_functionality(client->adapter, 272 I2C_FUNC_SMBUS_WORD_DATA | I2C_FUNC_SMBUS_BYTE)) 273 data->xfer = lidar_smbus_xfer; 274 else 275 return -EOPNOTSUPP; 276 277 indio_dev->info = &lidar_info; 278 indio_dev->name = LIDAR_DRV_NAME; 279 indio_dev->channels = lidar_channels; 280 indio_dev->num_channels = ARRAY_SIZE(lidar_channels); 281 indio_dev->modes = INDIO_DIRECT_MODE; 282 283 i2c_set_clientdata(client, indio_dev); 284 285 data->client = client; 286 data->indio_dev = indio_dev; 287 288 ret = iio_triggered_buffer_setup(indio_dev, NULL, 289 lidar_trigger_handler, NULL); 290 if (ret) 291 return ret; 292 293 ret = iio_device_register(indio_dev); 294 if (ret) 295 goto error_unreg_buffer; 296 297 pm_runtime_set_autosuspend_delay(&client->dev, 1000); 298 pm_runtime_use_autosuspend(&client->dev); 299 300 ret = pm_runtime_set_active(&client->dev); 301 if (ret) 302 goto error_unreg_buffer; 303 pm_runtime_enable(&client->dev); 304 pm_runtime_idle(&client->dev); 305 306 return 0; 307 308 error_unreg_buffer: 309 iio_triggered_buffer_cleanup(indio_dev); 310 311 return ret; 312 } 313 314 static int lidar_remove(struct i2c_client *client) 315 { 316 struct iio_dev *indio_dev = i2c_get_clientdata(client); 317 318 iio_device_unregister(indio_dev); 319 iio_triggered_buffer_cleanup(indio_dev); 320 321 pm_runtime_disable(&client->dev); 322 pm_runtime_set_suspended(&client->dev); 323 324 return 0; 325 } 326 327 static const struct i2c_device_id lidar_id[] = { 328 {"lidar-lite-v2", 0}, 329 {"lidar-lite-v3", 0}, 330 { }, 331 }; 332 MODULE_DEVICE_TABLE(i2c, lidar_id); 333 334 static const struct of_device_id lidar_dt_ids[] = { 335 { .compatible = "pulsedlight,lidar-lite-v2" }, 336 { .compatible = "grmn,lidar-lite-v3" }, 337 { } 338 }; 339 MODULE_DEVICE_TABLE(of, lidar_dt_ids); 340 341 #ifdef CONFIG_PM 342 static int lidar_pm_runtime_suspend(struct device *dev) 343 { 344 struct iio_dev *indio_dev = i2c_get_clientdata(to_i2c_client(dev)); 345 struct lidar_data *data = iio_priv(indio_dev); 346 347 return lidar_write_power(data, 0x0f); 348 } 349 350 static int lidar_pm_runtime_resume(struct device *dev) 351 { 352 struct iio_dev *indio_dev = i2c_get_clientdata(to_i2c_client(dev)); 353 struct lidar_data *data = iio_priv(indio_dev); 354 int ret = lidar_write_power(data, 0); 355 356 /* regulator and FPGA needs settling time */ 357 usleep_range(15000, 20000); 358 359 return ret; 360 } 361 #endif 362 363 static const struct dev_pm_ops lidar_pm_ops = { 364 SET_RUNTIME_PM_OPS(lidar_pm_runtime_suspend, 365 lidar_pm_runtime_resume, NULL) 366 }; 367 368 static struct i2c_driver lidar_driver = { 369 .driver = { 370 .name = LIDAR_DRV_NAME, 371 .of_match_table = of_match_ptr(lidar_dt_ids), 372 .pm = &lidar_pm_ops, 373 }, 374 .probe = lidar_probe, 375 .remove = lidar_remove, 376 .id_table = lidar_id, 377 }; 378 module_i2c_driver(lidar_driver); 379 380 MODULE_AUTHOR("Matt Ranostay <mranostay@gmail.com>"); 381 MODULE_DESCRIPTION("PulsedLight LIDAR sensor"); 382 MODULE_LICENSE("GPL"); 383