drivers/iio/proximity/pulsedlight-lidar-lite-v2.c

   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 *) &reg;
  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         mutex_lock(&indio_dev->mlock);
 207
 208         if (iio_buffer_enabled(indio_dev) && mask == IIO_CHAN_INFO_RAW) {
 209                 ret = -EBUSY;
 210                 goto error_busy;
 211         }
 212
 213         switch (mask) {
 214         case IIO_CHAN_INFO_RAW: {
 215                 u16 reg;
 216
 217                 ret = lidar_get_measurement(data, &reg);
 218                 if (!ret) {
 219                         *val = reg;
 220                         ret = IIO_VAL_INT;
 221                 }
 222                 break;
 223         }
 224         case IIO_CHAN_INFO_SCALE:
 225                 *val = 0;
 226                 *val2 = 10000;
 227                 ret = IIO_VAL_INT_PLUS_MICRO;
 228                 break;
 229         }
 230
 231 error_busy:
 232         mutex_unlock(&indio_dev->mlock);
 233
 234         return ret;
 235 }
 236
 237 static irqreturn_t lidar_trigger_handler(int irq, void *private)
 238 {
 239         struct iio_poll_func *pf = private;
 240         struct iio_dev *indio_dev = pf->indio_dev;
 241         struct lidar_data *data = iio_priv(indio_dev);
 242         int ret;
 243
 244         ret = lidar_get_measurement(data, data->buffer);
 245         if (!ret) {
 246                 iio_push_to_buffers_with_timestamp(indio_dev, data->buffer,
 247                                                    iio_get_time_ns());
 248         } else if (ret != -EINVAL) {
 249                 dev_err(&data->client->dev, "cannot read LIDAR measurement");
 250         }
 251
 252         iio_trigger_notify_done(indio_dev->trig);
 253
 254         return IRQ_HANDLED;
 255 }
 256
 257 static const struct iio_info lidar_info = {
 258         .driver_module = THIS_MODULE,
 259         .read_raw = lidar_read_raw,
 260 };
 261
 262 static int lidar_probe(struct i2c_client *client,
 263                        const struct i2c_device_id *id)
 264 {
 265         struct lidar_data *data;
 266         struct iio_dev *indio_dev;
 267         int ret;
 268
 269         indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data));
 270         if (!indio_dev)
 271                 return -ENOMEM;
 272         data = iio_priv(indio_dev);
 273
 274         if (i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) {
 275                 data->xfer = lidar_i2c_xfer;
 276                 data->i2c_enabled = 1;
 277         } else if (i2c_check_functionality(client->adapter,
 278                                 I2C_FUNC_SMBUS_WORD_DATA | I2C_FUNC_SMBUS_BYTE))
 279                 data->xfer = lidar_smbus_xfer;
 280         else
 281                 return -EOPNOTSUPP;
 282
 283         indio_dev->info = &lidar_info;
 284         indio_dev->name = LIDAR_DRV_NAME;
 285         indio_dev->channels = lidar_channels;
 286         indio_dev->num_channels = ARRAY_SIZE(lidar_channels);
 287         indio_dev->modes = INDIO_DIRECT_MODE;
 288
 289         i2c_set_clientdata(client, indio_dev);
 290
 291         data->client = client;
 292         data->indio_dev = indio_dev;
 293
 294         ret = iio_triggered_buffer_setup(indio_dev, NULL,
 295                                          lidar_trigger_handler, NULL);
 296         if (ret)
 297                 return ret;
 298
 299         ret = iio_device_register(indio_dev);
 300         if (ret)
 301                 goto error_unreg_buffer;
 302
 303         pm_runtime_set_autosuspend_delay(&client->dev, 1000);
 304         pm_runtime_use_autosuspend(&client->dev);
 305
 306         ret = pm_runtime_set_active(&client->dev);
 307         if (ret)
 308                 goto error_unreg_buffer;
 309         pm_runtime_enable(&client->dev);
 310
 311         pm_runtime_mark_last_busy(&client->dev);
 312         pm_runtime_idle(&client->dev);
 313
 314         return 0;
 315
 316 error_unreg_buffer:
 317         iio_triggered_buffer_cleanup(indio_dev);
 318
 319         return ret;
 320 }
 321
 322 static int lidar_remove(struct i2c_client *client)
 323 {
 324         struct iio_dev *indio_dev = i2c_get_clientdata(client);
 325
 326         iio_device_unregister(indio_dev);
 327         iio_triggered_buffer_cleanup(indio_dev);
 328
 329         pm_runtime_disable(&client->dev);
 330         pm_runtime_set_suspended(&client->dev);
 331
 332         return 0;
 333 }
 334
 335 static const struct i2c_device_id lidar_id[] = {
 336         {"lidar-lite-v2", 0},
 337         { },
 338 };
 339 MODULE_DEVICE_TABLE(i2c, lidar_id);
 340
 341 static const struct of_device_id lidar_dt_ids[] = {
 342         { .compatible = "pulsedlight,lidar-lite-v2" },
 343         { }
 344 };
 345 MODULE_DEVICE_TABLE(of, lidar_dt_ids);
 346
 347 #ifdef CONFIG_PM
 348 static int lidar_pm_runtime_suspend(struct device *dev)
 349 {
 350         struct iio_dev *indio_dev = i2c_get_clientdata(to_i2c_client(dev));
 351         struct lidar_data *data = iio_priv(indio_dev);
 352
 353         return lidar_write_power(data, 0x0f);
 354 }
 355
 356 static int lidar_pm_runtime_resume(struct device *dev)
 357 {
 358         struct iio_dev *indio_dev = i2c_get_clientdata(to_i2c_client(dev));
 359         struct lidar_data *data = iio_priv(indio_dev);
 360         int ret = lidar_write_power(data, 0);
 361
 362         /* regulator and FPGA needs settling time */
 363         usleep_range(15000, 20000);
 364
 365         return ret;
 366 }
 367 #endif
 368
 369 static const struct dev_pm_ops lidar_pm_ops = {
 370         SET_RUNTIME_PM_OPS(lidar_pm_runtime_suspend,
 371                            lidar_pm_runtime_resume, NULL)
 372 };
 373
 374 static struct i2c_driver lidar_driver = {
 375         .driver = {
 376                 .name   = LIDAR_DRV_NAME,
 377                 .of_match_table = of_match_ptr(lidar_dt_ids),
 378                 .pm     = &lidar_pm_ops,
 379         },
 380         .probe          = lidar_probe,
 381         .remove         = lidar_remove,
 382         .id_table       = lidar_id,
 383 };
 384 module_i2c_driver(lidar_driver);
 385
 386 MODULE_AUTHOR("Matt Ranostay <mranostay@gmail.com>");
 387 MODULE_DESCRIPTION("PulsedLight LIDAR sensor");
 388 MODULE_LICENSE("GPL");