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

   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         /* Ensure timestamp is naturally aligned */
  48         struct {
  49                 u16 chan;
  50                 s64 timestamp __aligned(8);
  51         } scan;
  52 };
  53
  54 static const struct iio_chan_spec lidar_channels[] = {
  55         {
  56                 .type = IIO_DISTANCE,
  57                 .info_mask_separate =
  58                         BIT(IIO_CHAN_INFO_RAW) | BIT(IIO_CHAN_INFO_SCALE),
  59                 .scan_index = 0,
  60                 .scan_type = {
  61                         .sign = 'u',
  62                         .realbits = 16,
  63                         .storagebits = 16,
  64                 },
  65         },
  66         IIO_CHAN_SOFT_TIMESTAMP(1),
  67 };
  68
  69 static int lidar_i2c_xfer(struct lidar_data *data, u8 reg, u8 *val, int len)
  70 {
  71         struct i2c_client *client = data->client;
  72         struct i2c_msg msg[2];
  73         int ret;
  74
  75         msg[0].addr = client->addr;
  76         msg[0].flags = client->flags | I2C_M_STOP;
  77         msg[0].len = 1;
  78         msg[0].buf  = (char *) &reg;
  79
  80         msg[1].addr = client->addr;
  81         msg[1].flags = client->flags | I2C_M_RD;
  82         msg[1].len = len;
  83         msg[1].buf = (char *) val;
  84
  85         ret = i2c_transfer(client->adapter, msg, 2);
  86
  87         return (ret == 2) ? 0 : -EIO;
  88 }
  89
  90 static int lidar_smbus_xfer(struct lidar_data *data, u8 reg, u8 *val, int len)
  91 {
  92         struct i2c_client *client = data->client;
  93         int ret;
  94
  95         /*
  96          * Device needs a STOP condition between address write, and data read
  97          * so in turn i2c_smbus_read_byte_data cannot be used
  98          */
  99
 100         while (len--) {
 101                 ret = i2c_smbus_write_byte(client, reg++);
 102                 if (ret < 0) {
 103                         dev_err(&client->dev, "cannot write addr value");
 104                         return ret;
 105                 }
 106
 107                 ret = i2c_smbus_read_byte(client);
 108                 if (ret < 0) {
 109                         dev_err(&client->dev, "cannot read data value");
 110                         return ret;
 111                 }
 112
 113                 *(val++) = ret;
 114         }
 115
 116         return 0;
 117 }
 118
 119 static int lidar_read_byte(struct lidar_data *data, u8 reg)
 120 {
 121         int ret;
 122         u8 val;
 123
 124         ret = data->xfer(data, reg, &val, 1);
 125         if (ret < 0)
 126                 return ret;
 127
 128         return val;
 129 }
 130
 131 static inline int lidar_write_control(struct lidar_data *data, int val)
 132 {
 133         return i2c_smbus_write_byte_data(data->client, LIDAR_REG_CONTROL, val);
 134 }
 135
 136 static inline int lidar_write_power(struct lidar_data *data, int val)
 137 {
 138         return i2c_smbus_write_byte_data(data->client,
 139                                          LIDAR_REG_PWR_CONTROL, val);
 140 }
 141
 142 static int lidar_read_measurement(struct lidar_data *data, u16 *reg)
 143 {
 144         __be16 value;
 145         int ret = data->xfer(data, LIDAR_REG_DATA_HBYTE |
 146                         (data->i2c_enabled ? LIDAR_REG_DATA_WORD_READ : 0),
 147                         (u8 *) &value, 2);
 148
 149         if (!ret)
 150                 *reg = be16_to_cpu(value);
 151
 152         return ret;
 153 }
 154
 155 static int lidar_get_measurement(struct lidar_data *data, u16 *reg)
 156 {
 157         struct i2c_client *client = data->client;
 158         int tries = 10;
 159         int ret;
 160
 161         ret = pm_runtime_resume_and_get(&client->dev);
 162         if (ret < 0)
 163                 return ret;
 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                 pm_runtime_put_noidle(&client->dev);
 170                 return ret;
 171         }
 172
 173         while (tries--) {
 174                 usleep_range(1000, 2000);
 175
 176                 ret = lidar_read_byte(data, LIDAR_REG_STATUS);
 177                 if (ret < 0)
 178                         break;
 179
 180                 /* return -EINVAL since laser is likely pointed out of range */
 181                 if (ret & LIDAR_REG_STATUS_INVALID) {
 182                         *reg = 0;
 183                         ret = -EINVAL;
 184                         break;
 185                 }
 186
 187                 /* sample ready to read */
 188                 if (!(ret & LIDAR_REG_STATUS_READY)) {
 189                         ret = lidar_read_measurement(data, reg);
 190                         break;
 191                 }
 192                 ret = -EIO;
 193         }
 194         pm_runtime_mark_last_busy(&client->dev);
 195         pm_runtime_put_autosuspend(&client->dev);
 196
 197         return ret;
 198 }
 199
 200 static int lidar_read_raw(struct iio_dev *indio_dev,
 201                           struct iio_chan_spec const *chan,
 202                           int *val, int *val2, long mask)
 203 {
 204         struct lidar_data *data = iio_priv(indio_dev);
 205         int ret = -EINVAL;
 206
 207         switch (mask) {
 208         case IIO_CHAN_INFO_RAW: {
 209                 u16 reg;
 210
 211                 if (iio_device_claim_direct_mode(indio_dev))
 212                         return -EBUSY;
 213
 214                 ret = lidar_get_measurement(data, &reg);
 215                 if (!ret) {
 216                         *val = reg;
 217                         ret = IIO_VAL_INT;
 218                 }
 219                 iio_device_release_direct_mode(indio_dev);
 220                 break;
 221         }
 222         case IIO_CHAN_INFO_SCALE:
 223                 *val = 0;
 224                 *val2 = 10000;
 225                 ret = IIO_VAL_INT_PLUS_MICRO;
 226                 break;
 227         }
 228
 229         return ret;
 230 }
 231
 232 static irqreturn_t lidar_trigger_handler(int irq, void *private)
 233 {
 234         struct iio_poll_func *pf = private;
 235         struct iio_dev *indio_dev = pf->indio_dev;
 236         struct lidar_data *data = iio_priv(indio_dev);
 237         int ret;
 238
 239         ret = lidar_get_measurement(data, &data->scan.chan);
 240         if (!ret) {
 241                 iio_push_to_buffers_with_timestamp(indio_dev, &data->scan,
 242                                                    iio_get_time_ns(indio_dev));
 243         } else if (ret != -EINVAL) {
 244                 dev_err(&data->client->dev, "cannot read LIDAR measurement");
 245         }
 246
 247         iio_trigger_notify_done(indio_dev->trig);
 248
 249         return IRQ_HANDLED;
 250 }
 251
 252 static const struct iio_info lidar_info = {
 253         .read_raw = lidar_read_raw,
 254 };
 255
 256 static int lidar_probe(struct i2c_client *client)
 257 {
 258         struct lidar_data *data;
 259         struct iio_dev *indio_dev;
 260         int ret;
 261
 262         indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data));
 263         if (!indio_dev)
 264                 return -ENOMEM;
 265         data = iio_priv(indio_dev);
 266
 267         if (i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) {
 268                 data->xfer = lidar_i2c_xfer;
 269                 data->i2c_enabled = 1;
 270         } else if (i2c_check_functionality(client->adapter,
 271                                 I2C_FUNC_SMBUS_WORD_DATA | I2C_FUNC_SMBUS_BYTE))
 272                 data->xfer = lidar_smbus_xfer;
 273         else
 274                 return -EOPNOTSUPP;
 275
 276         indio_dev->info = &lidar_info;
 277         indio_dev->name = LIDAR_DRV_NAME;
 278         indio_dev->channels = lidar_channels;
 279         indio_dev->num_channels = ARRAY_SIZE(lidar_channels);
 280         indio_dev->modes = INDIO_DIRECT_MODE;
 281
 282         i2c_set_clientdata(client, indio_dev);
 283
 284         data->client = client;
 285         data->indio_dev = indio_dev;
 286
 287         ret = iio_triggered_buffer_setup(indio_dev, NULL,
 288                                          lidar_trigger_handler, NULL);
 289         if (ret)
 290                 return ret;
 291
 292         ret = iio_device_register(indio_dev);
 293         if (ret)
 294                 goto error_unreg_buffer;
 295
 296         pm_runtime_set_autosuspend_delay(&client->dev, 1000);
 297         pm_runtime_use_autosuspend(&client->dev);
 298
 299         ret = pm_runtime_set_active(&client->dev);
 300         if (ret)
 301                 goto error_unreg_buffer;
 302         pm_runtime_enable(&client->dev);
 303         pm_runtime_idle(&client->dev);
 304
 305         return 0;
 306
 307 error_unreg_buffer:
 308         iio_triggered_buffer_cleanup(indio_dev);
 309
 310         return ret;
 311 }
 312
 313 static void lidar_remove(struct i2c_client *client)
 314 {
 315         struct iio_dev *indio_dev = i2c_get_clientdata(client);
 316
 317         iio_device_unregister(indio_dev);
 318         iio_triggered_buffer_cleanup(indio_dev);
 319
 320         pm_runtime_disable(&client->dev);
 321         pm_runtime_set_suspended(&client->dev);
 322 }
 323
 324 static const struct i2c_device_id lidar_id[] = {
 325         { "lidar-lite-v2" },
 326         { "lidar-lite-v3" },
 327         { }
 328 };
 329 MODULE_DEVICE_TABLE(i2c, lidar_id);
 330
 331 static const struct of_device_id lidar_dt_ids[] = {
 332         { .compatible = "pulsedlight,lidar-lite-v2" },
 333         { .compatible = "grmn,lidar-lite-v3" },
 334         { }
 335 };
 336 MODULE_DEVICE_TABLE(of, lidar_dt_ids);
 337
 338 static int lidar_pm_runtime_suspend(struct device *dev)
 339 {
 340         struct iio_dev *indio_dev = i2c_get_clientdata(to_i2c_client(dev));
 341         struct lidar_data *data = iio_priv(indio_dev);
 342
 343         return lidar_write_power(data, 0x0f);
 344 }
 345
 346 static int lidar_pm_runtime_resume(struct device *dev)
 347 {
 348         struct iio_dev *indio_dev = i2c_get_clientdata(to_i2c_client(dev));
 349         struct lidar_data *data = iio_priv(indio_dev);
 350         int ret = lidar_write_power(data, 0);
 351
 352         /* regulator and FPGA needs settling time */
 353         usleep_range(15000, 20000);
 354
 355         return ret;
 356 }
 357
 358 static const struct dev_pm_ops lidar_pm_ops = {
 359         RUNTIME_PM_OPS(lidar_pm_runtime_suspend, lidar_pm_runtime_resume, NULL)
 360 };
 361
 362 static struct i2c_driver lidar_driver = {
 363         .driver = {
 364                 .name   = LIDAR_DRV_NAME,
 365                 .of_match_table = lidar_dt_ids,
 366                 .pm     = pm_ptr(&lidar_pm_ops),
 367         },
 368         .probe          = lidar_probe,
 369         .remove         = lidar_remove,
 370         .id_table       = lidar_id,
 371 };
 372 module_i2c_driver(lidar_driver);
 373
 374 MODULE_AUTHOR("Matt Ranostay <matt.ranostay@konsulko.com>");
 375 MODULE_DESCRIPTION("PulsedLight LIDAR sensor");
 376 MODULE_LICENSE("GPL");