Matt Ranostay | cb119d5 | 2015-08-18 07:40:38 -0700 | [diff] [blame] | 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: runtime pm, 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/iio/iio.h> |
| 25 | #include <linux/iio/sysfs.h> |
| 26 | #include <linux/iio/buffer.h> |
| 27 | #include <linux/iio/trigger.h> |
| 28 | #include <linux/iio/triggered_buffer.h> |
| 29 | #include <linux/iio/trigger_consumer.h> |
| 30 | |
| 31 | #define LIDAR_REG_CONTROL 0x00 |
| 32 | #define LIDAR_REG_CONTROL_ACQUIRE BIT(2) |
| 33 | |
| 34 | #define LIDAR_REG_STATUS 0x01 |
| 35 | #define LIDAR_REG_STATUS_INVALID BIT(3) |
| 36 | #define LIDAR_REG_STATUS_READY BIT(0) |
| 37 | |
| 38 | #define LIDAR_REG_DATA_HBYTE 0x0f |
| 39 | #define LIDAR_REG_DATA_LBYTE 0x10 |
| 40 | |
| 41 | #define LIDAR_DRV_NAME "lidar" |
| 42 | |
| 43 | struct lidar_data { |
| 44 | struct iio_dev *indio_dev; |
| 45 | struct i2c_client *client; |
| 46 | |
| 47 | u16 buffer[8]; /* 2 byte distance + 8 byte timestamp */ |
| 48 | }; |
| 49 | |
| 50 | static const struct iio_chan_spec lidar_channels[] = { |
| 51 | { |
| 52 | .type = IIO_DISTANCE, |
| 53 | .info_mask_separate = |
| 54 | BIT(IIO_CHAN_INFO_RAW) | BIT(IIO_CHAN_INFO_SCALE), |
| 55 | .scan_index = 0, |
| 56 | .scan_type = { |
| 57 | .sign = 'u', |
| 58 | .realbits = 16, |
| 59 | .storagebits = 16, |
| 60 | }, |
| 61 | }, |
| 62 | IIO_CHAN_SOFT_TIMESTAMP(1), |
| 63 | }; |
| 64 | |
| 65 | static int lidar_read_byte(struct lidar_data *data, int reg) |
| 66 | { |
| 67 | struct i2c_client *client = data->client; |
| 68 | int ret; |
| 69 | |
| 70 | /* |
| 71 | * Device needs a STOP condition between address write, and data read |
| 72 | * so in turn i2c_smbus_read_byte_data cannot be used |
| 73 | */ |
| 74 | |
| 75 | ret = i2c_smbus_write_byte(client, reg); |
| 76 | if (ret < 0) { |
| 77 | dev_err(&client->dev, "cannot write addr value"); |
| 78 | return ret; |
| 79 | } |
| 80 | |
| 81 | ret = i2c_smbus_read_byte(client); |
| 82 | if (ret < 0) |
| 83 | dev_err(&client->dev, "cannot read data value"); |
| 84 | |
| 85 | return ret; |
| 86 | } |
| 87 | |
| 88 | static inline int lidar_write_control(struct lidar_data *data, int val) |
| 89 | { |
| 90 | return i2c_smbus_write_byte_data(data->client, LIDAR_REG_CONTROL, val); |
| 91 | } |
| 92 | |
| 93 | static int lidar_read_measurement(struct lidar_data *data, u16 *reg) |
| 94 | { |
| 95 | int ret; |
| 96 | int val; |
| 97 | |
| 98 | ret = lidar_read_byte(data, LIDAR_REG_DATA_HBYTE); |
| 99 | if (ret < 0) |
| 100 | return ret; |
| 101 | val = ret << 8; |
| 102 | |
| 103 | ret = lidar_read_byte(data, LIDAR_REG_DATA_LBYTE); |
| 104 | if (ret < 0) |
| 105 | return ret; |
| 106 | |
| 107 | val |= ret; |
| 108 | *reg = val; |
| 109 | |
| 110 | return 0; |
| 111 | } |
| 112 | |
| 113 | static int lidar_get_measurement(struct lidar_data *data, u16 *reg) |
| 114 | { |
| 115 | struct i2c_client *client = data->client; |
| 116 | int tries = 10; |
| 117 | int ret; |
| 118 | |
| 119 | /* start sample */ |
| 120 | ret = lidar_write_control(data, LIDAR_REG_CONTROL_ACQUIRE); |
| 121 | if (ret < 0) { |
| 122 | dev_err(&client->dev, "cannot send start measurement command"); |
| 123 | return ret; |
| 124 | } |
| 125 | |
| 126 | while (tries--) { |
| 127 | usleep_range(1000, 2000); |
| 128 | |
| 129 | ret = lidar_read_byte(data, LIDAR_REG_STATUS); |
| 130 | if (ret < 0) |
| 131 | break; |
| 132 | |
| 133 | /* return 0 since laser is likely pointed out of range */ |
| 134 | if (ret & LIDAR_REG_STATUS_INVALID) { |
| 135 | *reg = 0; |
| 136 | ret = 0; |
| 137 | break; |
| 138 | } |
| 139 | |
| 140 | /* sample ready to read */ |
| 141 | if (!(ret & LIDAR_REG_STATUS_READY)) { |
| 142 | ret = lidar_read_measurement(data, reg); |
| 143 | break; |
| 144 | } |
| 145 | ret = -EIO; |
| 146 | } |
| 147 | |
| 148 | return ret; |
| 149 | } |
| 150 | |
| 151 | static int lidar_read_raw(struct iio_dev *indio_dev, |
| 152 | struct iio_chan_spec const *chan, |
| 153 | int *val, int *val2, long mask) |
| 154 | { |
| 155 | struct lidar_data *data = iio_priv(indio_dev); |
| 156 | int ret = -EINVAL; |
| 157 | |
| 158 | mutex_lock(&indio_dev->mlock); |
| 159 | |
| 160 | if (iio_buffer_enabled(indio_dev) && mask == IIO_CHAN_INFO_RAW) { |
| 161 | ret = -EBUSY; |
| 162 | goto error_busy; |
| 163 | } |
| 164 | |
| 165 | switch (mask) { |
| 166 | case IIO_CHAN_INFO_RAW: { |
| 167 | u16 reg; |
| 168 | |
| 169 | ret = lidar_get_measurement(data, ®); |
| 170 | if (!ret) { |
| 171 | *val = reg; |
| 172 | ret = IIO_VAL_INT; |
| 173 | } |
| 174 | break; |
| 175 | } |
| 176 | case IIO_CHAN_INFO_SCALE: |
| 177 | *val = 0; |
| 178 | *val2 = 10000; |
| 179 | ret = IIO_VAL_INT_PLUS_MICRO; |
| 180 | break; |
| 181 | } |
| 182 | |
| 183 | error_busy: |
| 184 | mutex_unlock(&indio_dev->mlock); |
| 185 | |
| 186 | return ret; |
| 187 | } |
| 188 | |
| 189 | static irqreturn_t lidar_trigger_handler(int irq, void *private) |
| 190 | { |
| 191 | struct iio_poll_func *pf = private; |
| 192 | struct iio_dev *indio_dev = pf->indio_dev; |
| 193 | struct lidar_data *data = iio_priv(indio_dev); |
| 194 | int ret; |
| 195 | |
| 196 | ret = lidar_get_measurement(data, data->buffer); |
| 197 | if (!ret) { |
| 198 | iio_push_to_buffers_with_timestamp(indio_dev, data->buffer, |
| 199 | iio_get_time_ns()); |
| 200 | } else { |
| 201 | dev_err(&data->client->dev, "cannot read LIDAR measurement"); |
| 202 | } |
| 203 | |
| 204 | iio_trigger_notify_done(indio_dev->trig); |
| 205 | |
| 206 | return IRQ_HANDLED; |
| 207 | } |
| 208 | |
| 209 | static const struct iio_info lidar_info = { |
| 210 | .driver_module = THIS_MODULE, |
| 211 | .read_raw = lidar_read_raw, |
| 212 | }; |
| 213 | |
| 214 | static int lidar_probe(struct i2c_client *client, |
| 215 | const struct i2c_device_id *id) |
| 216 | { |
| 217 | struct lidar_data *data; |
| 218 | struct iio_dev *indio_dev; |
| 219 | int ret; |
| 220 | |
| 221 | indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data)); |
| 222 | if (!indio_dev) |
| 223 | return -ENOMEM; |
| 224 | |
| 225 | indio_dev->info = &lidar_info; |
| 226 | indio_dev->name = LIDAR_DRV_NAME; |
| 227 | indio_dev->channels = lidar_channels; |
| 228 | indio_dev->num_channels = ARRAY_SIZE(lidar_channels); |
| 229 | indio_dev->modes = INDIO_DIRECT_MODE; |
| 230 | |
| 231 | data = iio_priv(indio_dev); |
| 232 | i2c_set_clientdata(client, indio_dev); |
| 233 | |
| 234 | data->client = client; |
| 235 | data->indio_dev = indio_dev; |
| 236 | |
| 237 | ret = iio_triggered_buffer_setup(indio_dev, NULL, |
| 238 | lidar_trigger_handler, NULL); |
| 239 | if (ret) |
| 240 | return ret; |
| 241 | |
| 242 | ret = iio_device_register(indio_dev); |
| 243 | if (ret) |
| 244 | goto error_unreg_buffer; |
| 245 | |
| 246 | return 0; |
| 247 | |
| 248 | error_unreg_buffer: |
| 249 | iio_triggered_buffer_cleanup(indio_dev); |
| 250 | |
| 251 | return ret; |
| 252 | } |
| 253 | |
| 254 | static int lidar_remove(struct i2c_client *client) |
| 255 | { |
| 256 | struct iio_dev *indio_dev = i2c_get_clientdata(client); |
| 257 | |
| 258 | iio_device_unregister(indio_dev); |
| 259 | iio_triggered_buffer_cleanup(indio_dev); |
| 260 | |
| 261 | return 0; |
| 262 | } |
| 263 | |
| 264 | static const struct i2c_device_id lidar_id[] = { |
| 265 | {"lidar-lite-v2", 0}, |
| 266 | { }, |
| 267 | }; |
| 268 | MODULE_DEVICE_TABLE(i2c, lidar_id); |
| 269 | |
| 270 | static const struct of_device_id lidar_dt_ids[] = { |
| 271 | { .compatible = "pulsedlight,lidar-lite-v2" }, |
| 272 | { } |
| 273 | }; |
Matt Ranostay | 80cf2b5 | 2015-09-22 23:22:03 -0700 | [diff] [blame] | 274 | MODULE_DEVICE_TABLE(of, lidar_dt_ids); |
Matt Ranostay | cb119d5 | 2015-08-18 07:40:38 -0700 | [diff] [blame] | 275 | |
| 276 | static struct i2c_driver lidar_driver = { |
| 277 | .driver = { |
| 278 | .name = LIDAR_DRV_NAME, |
| 279 | .of_match_table = of_match_ptr(lidar_dt_ids), |
| 280 | }, |
| 281 | .probe = lidar_probe, |
| 282 | .remove = lidar_remove, |
| 283 | .id_table = lidar_id, |
| 284 | }; |
| 285 | module_i2c_driver(lidar_driver); |
| 286 | |
| 287 | MODULE_AUTHOR("Matt Ranostay <mranostay@gmail.com>"); |
| 288 | MODULE_DESCRIPTION("PulsedLight LIDAR sensor"); |
| 289 | MODULE_LICENSE("GPL"); |