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 11 #include <linux/err.h> 12 #include <linux/init.h> 13 #include <linux/i2c.h> 14 #include <linux/delay.h> 15 #include <linux/module.h> 16 #include <linux/mod_devicetable.h> 17 #include <linux/pm_runtime.h> 18 #include <linux/iio/iio.h> 19 #include <linux/iio/sysfs.h> 20 #include <linux/iio/buffer.h> 21 #include <linux/iio/trigger.h> 22 #include <linux/iio/triggered_buffer.h> 23 #include <linux/iio/trigger_consumer.h> 24 25 #define LIDAR_REG_CONTROL 0x00 26 #define LIDAR_REG_CONTROL_ACQUIRE BIT(2) 27 28 #define LIDAR_REG_STATUS 0x01 29 #define LIDAR_REG_STATUS_INVALID BIT(3) 30 #define LIDAR_REG_STATUS_READY BIT(0) 31 32 #define LIDAR_REG_DATA_HBYTE 0x0f 33 #define LIDAR_REG_DATA_LBYTE 0x10 34 #define LIDAR_REG_DATA_WORD_READ BIT(7) 35 36 #define LIDAR_REG_PWR_CONTROL 0x65 37 38 #define LIDAR_DRV_NAME "lidar" 39 40 struct lidar_data { 41 struct iio_dev *indio_dev; 42 struct i2c_client *client; 43 44 int (*xfer)(struct lidar_data *data, u8 reg, u8 *val, int len); 45 int i2c_enabled; 46 }; 47 48 static const struct iio_chan_spec lidar_channels[] = { 49 { 50 .type = IIO_DISTANCE, 51 .info_mask_separate = 52 BIT(IIO_CHAN_INFO_RAW) | BIT(IIO_CHAN_INFO_SCALE), 53 .scan_index = 0, 54 .scan_type = { 55 .sign = 'u', 56 .realbits = 16, 57 .storagebits = 16, 58 }, 59 }, 60 IIO_CHAN_SOFT_TIMESTAMP(1), 61 }; 62 63 static int lidar_i2c_xfer(struct lidar_data *data, u8 reg, u8 *val, int len) 64 { 65 struct i2c_client *client = data->client; 66 struct i2c_msg msg[2]; 67 int ret; 68 69 msg[0].addr = client->addr; 70 msg[0].flags = client->flags | I2C_M_STOP; 71 msg[0].len = 1; 72 msg[0].buf = (char *) ® 73 74 msg[1].addr = client->addr; 75 msg[1].flags = client->flags | I2C_M_RD; 76 msg[1].len = len; 77 msg[1].buf = (char *) val; 78 79 ret = i2c_transfer(client->adapter, msg, 2); 80 81 return (ret == 2) ? 0 : -EIO; 82 } 83 84 static int lidar_smbus_xfer(struct lidar_data *data, u8 reg, u8 *val, int len) 85 { 86 struct i2c_client *client = data->client; 87 int ret; 88 89 /* 90 * Device needs a STOP condition between address write, and data read 91 * so in turn i2c_smbus_read_byte_data cannot be used 92 */ 93 94 while (len--) { 95 ret = i2c_smbus_write_byte(client, reg++); 96 if (ret < 0) { 97 dev_err(&client->dev, "cannot write addr value"); 98 return ret; 99 } 100 101 ret = i2c_smbus_read_byte(client); 102 if (ret < 0) { 103 dev_err(&client->dev, "cannot read data value"); 104 return ret; 105 } 106 107 *(val++) = ret; 108 } 109 110 return 0; 111 } 112 113 static int lidar_read_byte(struct lidar_data *data, u8 reg) 114 { 115 int ret; 116 u8 val; 117 118 ret = data->xfer(data, reg, &val, 1); 119 if (ret < 0) 120 return ret; 121 122 return val; 123 } 124 125 static inline int lidar_write_control(struct lidar_data *data, int val) 126 { 127 return i2c_smbus_write_byte_data(data->client, LIDAR_REG_CONTROL, val); 128 } 129 130 static inline int lidar_write_power(struct lidar_data *data, int val) 131 { 132 return i2c_smbus_write_byte_data(data->client, 133 LIDAR_REG_PWR_CONTROL, val); 134 } 135 136 static int lidar_read_measurement(struct lidar_data *data, u16 *reg) 137 { 138 __be16 value; 139 int ret = data->xfer(data, LIDAR_REG_DATA_HBYTE | 140 (data->i2c_enabled ? LIDAR_REG_DATA_WORD_READ : 0), 141 (u8 *) &value, 2); 142 143 if (!ret) 144 *reg = be16_to_cpu(value); 145 146 return ret; 147 } 148 149 static int lidar_get_measurement(struct lidar_data *data, u16 *reg) 150 { 151 struct i2c_client *client = data->client; 152 int tries = 10; 153 int ret; 154 155 ret = pm_runtime_resume_and_get(&client->dev); 156 if (ret < 0) 157 return ret; 158 159 /* start sample */ 160 ret = lidar_write_control(data, LIDAR_REG_CONTROL_ACQUIRE); 161 if (ret < 0) { 162 dev_err(&client->dev, "cannot send start measurement command"); 163 pm_runtime_put_noidle(&client->dev); 164 return ret; 165 } 166 167 while (tries--) { 168 usleep_range(1000, 2000); 169 170 ret = lidar_read_byte(data, LIDAR_REG_STATUS); 171 if (ret < 0) 172 break; 173 174 /* return -EINVAL since laser is likely pointed out of range */ 175 if (ret & LIDAR_REG_STATUS_INVALID) { 176 *reg = 0; 177 ret = -EINVAL; 178 break; 179 } 180 181 /* sample ready to read */ 182 if (!(ret & LIDAR_REG_STATUS_READY)) { 183 ret = lidar_read_measurement(data, reg); 184 break; 185 } 186 ret = -EIO; 187 } 188 pm_runtime_put_autosuspend(&client->dev); 189 190 return ret; 191 } 192 193 static int lidar_read_raw(struct iio_dev *indio_dev, 194 struct iio_chan_spec const *chan, 195 int *val, int *val2, long mask) 196 { 197 struct lidar_data *data = iio_priv(indio_dev); 198 int ret = -EINVAL; 199 200 switch (mask) { 201 case IIO_CHAN_INFO_RAW: { 202 u16 reg; 203 204 if (!iio_device_claim_direct(indio_dev)) 205 return -EBUSY; 206 207 ret = lidar_get_measurement(data, ®); 208 if (!ret) { 209 *val = reg; 210 ret = IIO_VAL_INT; 211 } 212 iio_device_release_direct(indio_dev); 213 break; 214 } 215 case IIO_CHAN_INFO_SCALE: 216 *val = 0; 217 *val2 = 10000; 218 ret = IIO_VAL_INT_PLUS_MICRO; 219 break; 220 } 221 222 return ret; 223 } 224 225 static irqreturn_t lidar_trigger_handler(int irq, void *private) 226 { 227 struct iio_poll_func *pf = private; 228 struct iio_dev *indio_dev = pf->indio_dev; 229 struct lidar_data *data = iio_priv(indio_dev); 230 int ret; 231 struct { 232 u16 chan; 233 aligned_s64 timestamp; 234 } scan = { }; 235 236 ret = lidar_get_measurement(data, &scan.chan); 237 if (!ret) { 238 iio_push_to_buffers_with_ts(indio_dev, &scan, sizeof(scan), 239 iio_get_time_ns(indio_dev)); 240 } else if (ret != -EINVAL) { 241 dev_err(&data->client->dev, "cannot read LIDAR measurement"); 242 } 243 244 iio_trigger_notify_done(indio_dev->trig); 245 246 return IRQ_HANDLED; 247 } 248 249 static const struct iio_info lidar_info = { 250 .read_raw = lidar_read_raw, 251 }; 252 253 static int lidar_probe(struct i2c_client *client) 254 { 255 struct lidar_data *data; 256 struct iio_dev *indio_dev; 257 int ret; 258 259 indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data)); 260 if (!indio_dev) 261 return -ENOMEM; 262 data = iio_priv(indio_dev); 263 264 if (i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) { 265 data->xfer = lidar_i2c_xfer; 266 data->i2c_enabled = 1; 267 } else if (i2c_check_functionality(client->adapter, 268 I2C_FUNC_SMBUS_WORD_DATA | I2C_FUNC_SMBUS_BYTE)) 269 data->xfer = lidar_smbus_xfer; 270 else 271 return -EOPNOTSUPP; 272 273 indio_dev->info = &lidar_info; 274 indio_dev->name = LIDAR_DRV_NAME; 275 indio_dev->channels = lidar_channels; 276 indio_dev->num_channels = ARRAY_SIZE(lidar_channels); 277 indio_dev->modes = INDIO_DIRECT_MODE; 278 279 i2c_set_clientdata(client, indio_dev); 280 281 data->client = client; 282 data->indio_dev = indio_dev; 283 284 ret = iio_triggered_buffer_setup(indio_dev, NULL, 285 lidar_trigger_handler, NULL); 286 if (ret) 287 return ret; 288 289 ret = iio_device_register(indio_dev); 290 if (ret) 291 goto error_unreg_buffer; 292 293 pm_runtime_set_autosuspend_delay(&client->dev, 1000); 294 pm_runtime_use_autosuspend(&client->dev); 295 296 ret = pm_runtime_set_active(&client->dev); 297 if (ret) 298 goto error_unreg_buffer; 299 pm_runtime_enable(&client->dev); 300 pm_runtime_idle(&client->dev); 301 302 return 0; 303 304 error_unreg_buffer: 305 iio_triggered_buffer_cleanup(indio_dev); 306 307 return ret; 308 } 309 310 static void lidar_remove(struct i2c_client *client) 311 { 312 struct iio_dev *indio_dev = i2c_get_clientdata(client); 313 314 iio_device_unregister(indio_dev); 315 iio_triggered_buffer_cleanup(indio_dev); 316 317 pm_runtime_disable(&client->dev); 318 pm_runtime_set_suspended(&client->dev); 319 } 320 321 static const struct i2c_device_id lidar_id[] = { 322 { "lidar-lite-v2" }, 323 { "lidar-lite-v3" }, 324 { } 325 }; 326 MODULE_DEVICE_TABLE(i2c, lidar_id); 327 328 static const struct of_device_id lidar_dt_ids[] = { 329 { .compatible = "pulsedlight,lidar-lite-v2" }, 330 { .compatible = "grmn,lidar-lite-v3" }, 331 { } 332 }; 333 MODULE_DEVICE_TABLE(of, lidar_dt_ids); 334 335 static int lidar_pm_runtime_suspend(struct device *dev) 336 { 337 struct iio_dev *indio_dev = i2c_get_clientdata(to_i2c_client(dev)); 338 struct lidar_data *data = iio_priv(indio_dev); 339 340 return lidar_write_power(data, 0x0f); 341 } 342 343 static int lidar_pm_runtime_resume(struct device *dev) 344 { 345 struct iio_dev *indio_dev = i2c_get_clientdata(to_i2c_client(dev)); 346 struct lidar_data *data = iio_priv(indio_dev); 347 int ret = lidar_write_power(data, 0); 348 349 /* regulator and FPGA needs settling time */ 350 usleep_range(15000, 20000); 351 352 return ret; 353 } 354 355 static const struct dev_pm_ops lidar_pm_ops = { 356 RUNTIME_PM_OPS(lidar_pm_runtime_suspend, lidar_pm_runtime_resume, NULL) 357 }; 358 359 static struct i2c_driver lidar_driver = { 360 .driver = { 361 .name = LIDAR_DRV_NAME, 362 .of_match_table = lidar_dt_ids, 363 .pm = pm_ptr(&lidar_pm_ops), 364 }, 365 .probe = lidar_probe, 366 .remove = lidar_remove, 367 .id_table = lidar_id, 368 }; 369 module_i2c_driver(lidar_driver); 370 371 MODULE_AUTHOR("Matt Ranostay <matt.ranostay@konsulko.com>"); 372 MODULE_DESCRIPTION("PulsedLight LIDAR sensor"); 373 MODULE_LICENSE("GPL"); 374