1 /* 2 * itg3200_core.c -- support InvenSense ITG3200 3 * Digital 3-Axis Gyroscope driver 4 * 5 * Copyright (c) 2011 Christian Strobel <christian.strobel@iis.fraunhofer.de> 6 * Copyright (c) 2011 Manuel Stahl <manuel.stahl@iis.fraunhofer.de> 7 * Copyright (c) 2012 Thorsten Nowak <thorsten.nowak@iis.fraunhofer.de> 8 * 9 * This program is free software; you can redistribute it and/or modify 10 * it under the terms of the GNU General Public License version 2 as 11 * published by the Free Software Foundation. 12 * 13 * TODO: 14 * - Support digital low pass filter 15 * - Support power management 16 */ 17 18 #include <linux/interrupt.h> 19 #include <linux/irq.h> 20 #include <linux/i2c.h> 21 #include <linux/gpio.h> 22 #include <linux/slab.h> 23 #include <linux/stat.h> 24 #include <linux/module.h> 25 #include <linux/delay.h> 26 27 #include <linux/iio/iio.h> 28 #include <linux/iio/sysfs.h> 29 #include <linux/iio/events.h> 30 #include <linux/iio/buffer.h> 31 32 #include <linux/iio/gyro/itg3200.h> 33 34 35 int itg3200_write_reg_8(struct iio_dev *indio_dev, 36 u8 reg_address, u8 val) 37 { 38 struct itg3200 *st = iio_priv(indio_dev); 39 40 return i2c_smbus_write_byte_data(st->i2c, 0x80 | reg_address, val); 41 } 42 43 int itg3200_read_reg_8(struct iio_dev *indio_dev, 44 u8 reg_address, u8 *val) 45 { 46 struct itg3200 *st = iio_priv(indio_dev); 47 int ret; 48 49 ret = i2c_smbus_read_byte_data(st->i2c, reg_address); 50 if (ret < 0) 51 return ret; 52 *val = ret; 53 return 0; 54 } 55 56 static int itg3200_read_reg_s16(struct iio_dev *indio_dev, u8 lower_reg_address, 57 int *val) 58 { 59 struct itg3200 *st = iio_priv(indio_dev); 60 struct i2c_client *client = st->i2c; 61 int ret; 62 s16 out; 63 64 struct i2c_msg msg[2] = { 65 { 66 .addr = client->addr, 67 .flags = client->flags, 68 .len = 1, 69 .buf = (char *)&lower_reg_address, 70 }, 71 { 72 .addr = client->addr, 73 .flags = client->flags | I2C_M_RD, 74 .len = 2, 75 .buf = (char *)&out, 76 }, 77 }; 78 79 lower_reg_address |= 0x80; 80 ret = i2c_transfer(client->adapter, msg, 2); 81 be16_to_cpus(&out); 82 *val = out; 83 84 return (ret == 2) ? 0 : ret; 85 } 86 87 static int itg3200_read_raw(struct iio_dev *indio_dev, 88 const struct iio_chan_spec *chan, 89 int *val, int *val2, long info) 90 { 91 int ret = 0; 92 u8 reg; 93 u8 regval; 94 95 switch (info) { 96 case IIO_CHAN_INFO_RAW: 97 reg = (u8)chan->address; 98 ret = itg3200_read_reg_s16(indio_dev, reg, val); 99 return IIO_VAL_INT; 100 case IIO_CHAN_INFO_SCALE: 101 *val = 0; 102 if (chan->type == IIO_TEMP) 103 *val2 = 1000000000/280; 104 else 105 *val2 = 1214142; /* (1 / 14,375) * (PI / 180) */ 106 return IIO_VAL_INT_PLUS_NANO; 107 case IIO_CHAN_INFO_OFFSET: 108 /* Only the temperature channel has an offset */ 109 *val = 23000; 110 return IIO_VAL_INT; 111 case IIO_CHAN_INFO_SAMP_FREQ: 112 ret = itg3200_read_reg_8(indio_dev, ITG3200_REG_DLPF, ®val); 113 if (ret) 114 return ret; 115 116 *val = (regval & ITG3200_DLPF_CFG_MASK) ? 1000 : 8000; 117 118 ret = itg3200_read_reg_8(indio_dev, 119 ITG3200_REG_SAMPLE_RATE_DIV, 120 ®val); 121 if (ret) 122 return ret; 123 124 *val /= regval + 1; 125 return IIO_VAL_INT; 126 127 default: 128 return -EINVAL; 129 } 130 } 131 132 static int itg3200_write_raw(struct iio_dev *indio_dev, 133 struct iio_chan_spec const *chan, 134 int val, 135 int val2, 136 long mask) 137 { 138 int ret; 139 u8 t; 140 141 switch (mask) { 142 case IIO_CHAN_INFO_SAMP_FREQ: 143 if (val == 0 || val2 != 0) 144 return -EINVAL; 145 146 mutex_lock(&indio_dev->mlock); 147 148 ret = itg3200_read_reg_8(indio_dev, ITG3200_REG_DLPF, &t); 149 if (ret) { 150 mutex_unlock(&indio_dev->mlock); 151 return ret; 152 } 153 t = ((t & ITG3200_DLPF_CFG_MASK) ? 1000u : 8000u) / val - 1; 154 155 ret = itg3200_write_reg_8(indio_dev, 156 ITG3200_REG_SAMPLE_RATE_DIV, 157 t); 158 159 mutex_unlock(&indio_dev->mlock); 160 return ret; 161 162 default: 163 return -EINVAL; 164 } 165 } 166 167 /* 168 * Reset device and internal registers to the power-up-default settings 169 * Use the gyro clock as reference, as suggested by the datasheet 170 */ 171 static int itg3200_reset(struct iio_dev *indio_dev) 172 { 173 struct itg3200 *st = iio_priv(indio_dev); 174 int ret; 175 176 dev_dbg(&st->i2c->dev, "reset device"); 177 178 ret = itg3200_write_reg_8(indio_dev, 179 ITG3200_REG_POWER_MANAGEMENT, 180 ITG3200_RESET); 181 if (ret) { 182 dev_err(&st->i2c->dev, "error resetting device"); 183 goto error_ret; 184 } 185 186 /* Wait for PLL (1ms according to datasheet) */ 187 udelay(1500); 188 189 ret = itg3200_write_reg_8(indio_dev, 190 ITG3200_REG_IRQ_CONFIG, 191 ITG3200_IRQ_ACTIVE_HIGH | 192 ITG3200_IRQ_PUSH_PULL | 193 ITG3200_IRQ_LATCH_50US_PULSE | 194 ITG3200_IRQ_LATCH_CLEAR_ANY); 195 196 if (ret) 197 dev_err(&st->i2c->dev, "error init device"); 198 199 error_ret: 200 return ret; 201 } 202 203 /* itg3200_enable_full_scale() - Disables the digital low pass filter */ 204 static int itg3200_enable_full_scale(struct iio_dev *indio_dev) 205 { 206 u8 val; 207 int ret; 208 209 ret = itg3200_read_reg_8(indio_dev, ITG3200_REG_DLPF, &val); 210 if (ret) 211 goto err_ret; 212 213 val |= ITG3200_DLPF_FS_SEL_2000; 214 return itg3200_write_reg_8(indio_dev, ITG3200_REG_DLPF, val); 215 216 err_ret: 217 return ret; 218 } 219 220 static int itg3200_initial_setup(struct iio_dev *indio_dev) 221 { 222 struct itg3200 *st = iio_priv(indio_dev); 223 int ret; 224 u8 val; 225 226 ret = itg3200_reset(indio_dev); 227 if (ret) 228 goto err_ret; 229 230 ret = itg3200_read_reg_8(indio_dev, ITG3200_REG_ADDRESS, &val); 231 if (ret) 232 goto err_ret; 233 234 if (((val >> 1) & 0x3f) != 0x34) { 235 dev_err(&st->i2c->dev, "invalid reg value 0x%02x", val); 236 ret = -ENXIO; 237 goto err_ret; 238 } 239 240 ret = itg3200_enable_full_scale(indio_dev); 241 err_ret: 242 return ret; 243 } 244 245 #define ITG3200_ST \ 246 { .sign = 's', .realbits = 16, .storagebits = 16, .endianness = IIO_BE } 247 248 #define ITG3200_GYRO_CHAN(_mod) { \ 249 .type = IIO_ANGL_VEL, \ 250 .modified = 1, \ 251 .channel2 = IIO_MOD_ ## _mod, \ 252 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \ 253 .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE), \ 254 .info_mask_shared_by_all = BIT(IIO_CHAN_INFO_SAMP_FREQ), \ 255 .address = ITG3200_REG_GYRO_ ## _mod ## OUT_H, \ 256 .scan_index = ITG3200_SCAN_GYRO_ ## _mod, \ 257 .scan_type = ITG3200_ST, \ 258 } 259 260 static const struct iio_chan_spec itg3200_channels[] = { 261 { 262 .type = IIO_TEMP, 263 .channel2 = IIO_NO_MOD, 264 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), 265 .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_OFFSET) | 266 BIT(IIO_CHAN_INFO_SCALE), 267 .info_mask_shared_by_all = BIT(IIO_CHAN_INFO_SAMP_FREQ), 268 .address = ITG3200_REG_TEMP_OUT_H, 269 .scan_index = ITG3200_SCAN_TEMP, 270 .scan_type = ITG3200_ST, 271 }, 272 ITG3200_GYRO_CHAN(X), 273 ITG3200_GYRO_CHAN(Y), 274 ITG3200_GYRO_CHAN(Z), 275 IIO_CHAN_SOFT_TIMESTAMP(ITG3200_SCAN_ELEMENTS), 276 }; 277 278 static const struct iio_info itg3200_info = { 279 .read_raw = &itg3200_read_raw, 280 .write_raw = &itg3200_write_raw, 281 .driver_module = THIS_MODULE, 282 }; 283 284 static const unsigned long itg3200_available_scan_masks[] = { 0xffffffff, 0x0 }; 285 286 static int itg3200_probe(struct i2c_client *client, 287 const struct i2c_device_id *id) 288 { 289 int ret; 290 struct itg3200 *st; 291 struct iio_dev *indio_dev; 292 293 dev_dbg(&client->dev, "probe I2C dev with IRQ %i", client->irq); 294 295 indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*st)); 296 if (!indio_dev) 297 return -ENOMEM; 298 299 st = iio_priv(indio_dev); 300 301 i2c_set_clientdata(client, indio_dev); 302 st->i2c = client; 303 304 indio_dev->dev.parent = &client->dev; 305 indio_dev->name = client->dev.driver->name; 306 indio_dev->channels = itg3200_channels; 307 indio_dev->num_channels = ARRAY_SIZE(itg3200_channels); 308 indio_dev->available_scan_masks = itg3200_available_scan_masks; 309 indio_dev->info = &itg3200_info; 310 indio_dev->modes = INDIO_DIRECT_MODE; 311 312 ret = itg3200_buffer_configure(indio_dev); 313 if (ret) 314 return ret; 315 316 if (client->irq) { 317 ret = itg3200_probe_trigger(indio_dev); 318 if (ret) 319 goto error_unconfigure_buffer; 320 } 321 322 ret = itg3200_initial_setup(indio_dev); 323 if (ret) 324 goto error_remove_trigger; 325 326 ret = iio_device_register(indio_dev); 327 if (ret) 328 goto error_remove_trigger; 329 330 return 0; 331 332 error_remove_trigger: 333 if (client->irq) 334 itg3200_remove_trigger(indio_dev); 335 error_unconfigure_buffer: 336 itg3200_buffer_unconfigure(indio_dev); 337 return ret; 338 } 339 340 static int itg3200_remove(struct i2c_client *client) 341 { 342 struct iio_dev *indio_dev = i2c_get_clientdata(client); 343 344 iio_device_unregister(indio_dev); 345 346 if (client->irq) 347 itg3200_remove_trigger(indio_dev); 348 349 itg3200_buffer_unconfigure(indio_dev); 350 351 return 0; 352 } 353 354 static int __maybe_unused itg3200_suspend(struct device *dev) 355 { 356 struct iio_dev *indio_dev = dev_get_drvdata(dev); 357 struct itg3200 *st = iio_priv(indio_dev); 358 359 dev_dbg(&st->i2c->dev, "suspend device"); 360 361 return itg3200_write_reg_8(indio_dev, ITG3200_REG_POWER_MANAGEMENT, 362 ITG3200_SLEEP); 363 } 364 365 static int __maybe_unused itg3200_resume(struct device *dev) 366 { 367 struct iio_dev *indio_dev = dev_get_drvdata(dev); 368 369 return itg3200_initial_setup(indio_dev); 370 } 371 372 static SIMPLE_DEV_PM_OPS(itg3200_pm_ops, itg3200_suspend, itg3200_resume); 373 374 static const struct i2c_device_id itg3200_id[] = { 375 { "itg3200", 0 }, 376 { } 377 }; 378 MODULE_DEVICE_TABLE(i2c, itg3200_id); 379 380 static const struct of_device_id itg3200_of_match[] = { 381 { .compatible = "invensense,itg3200" }, 382 { } 383 }; 384 MODULE_DEVICE_TABLE(of, itg3200_of_match); 385 386 static struct i2c_driver itg3200_driver = { 387 .driver = { 388 .name = "itg3200", 389 .of_match_table = itg3200_of_match, 390 .pm = &itg3200_pm_ops, 391 }, 392 .id_table = itg3200_id, 393 .probe = itg3200_probe, 394 .remove = itg3200_remove, 395 }; 396 397 module_i2c_driver(itg3200_driver); 398 399 MODULE_AUTHOR("Christian Strobel <christian.strobel@iis.fraunhofer.de>"); 400 MODULE_DESCRIPTION("ITG3200 Gyroscope I2C driver"); 401 MODULE_LICENSE("GPL v2"); 402