1 /* 2 * ADXRS450/ADXRS453 Digital Output Gyroscope Driver 3 * 4 * Copyright 2011 Analog Devices Inc. 5 * 6 * Licensed under the GPL-2. 7 */ 8 9 #include <linux/interrupt.h> 10 #include <linux/irq.h> 11 #include <linux/delay.h> 12 #include <linux/mutex.h> 13 #include <linux/device.h> 14 #include <linux/kernel.h> 15 #include <linux/spi/spi.h> 16 #include <linux/slab.h> 17 #include <linux/sysfs.h> 18 #include <linux/list.h> 19 #include <linux/module.h> 20 21 #include <linux/iio/iio.h> 22 #include <linux/iio/sysfs.h> 23 24 #define ADXRS450_STARTUP_DELAY 50 /* ms */ 25 26 /* The MSB for the spi commands */ 27 #define ADXRS450_SENSOR_DATA (0x20 << 24) 28 #define ADXRS450_WRITE_DATA (0x40 << 24) 29 #define ADXRS450_READ_DATA (0x80 << 24) 30 31 #define ADXRS450_RATE1 0x00 /* Rate Registers */ 32 #define ADXRS450_TEMP1 0x02 /* Temperature Registers */ 33 #define ADXRS450_LOCST1 0x04 /* Low CST Memory Registers */ 34 #define ADXRS450_HICST1 0x06 /* High CST Memory Registers */ 35 #define ADXRS450_QUAD1 0x08 /* Quad Memory Registers */ 36 #define ADXRS450_FAULT1 0x0A /* Fault Registers */ 37 #define ADXRS450_PID1 0x0C /* Part ID Register 1 */ 38 #define ADXRS450_SNH 0x0E /* Serial Number Registers, 4 bytes */ 39 #define ADXRS450_SNL 0x10 40 #define ADXRS450_DNC1 0x12 /* Dynamic Null Correction Registers */ 41 /* Check bits */ 42 #define ADXRS450_P 0x01 43 #define ADXRS450_CHK 0x02 44 #define ADXRS450_CST 0x04 45 #define ADXRS450_PWR 0x08 46 #define ADXRS450_POR 0x10 47 #define ADXRS450_NVM 0x20 48 #define ADXRS450_Q 0x40 49 #define ADXRS450_PLL 0x80 50 #define ADXRS450_UV 0x100 51 #define ADXRS450_OV 0x200 52 #define ADXRS450_AMP 0x400 53 #define ADXRS450_FAIL 0x800 54 55 #define ADXRS450_WRERR_MASK (0x7 << 29) 56 57 #define ADXRS450_MAX_RX 4 58 #define ADXRS450_MAX_TX 4 59 60 #define ADXRS450_GET_ST(a) ((a >> 26) & 0x3) 61 62 enum { 63 ID_ADXRS450, 64 ID_ADXRS453, 65 }; 66 67 /** 68 * struct adxrs450_state - device instance specific data 69 * @us: actual spi_device 70 * @buf_lock: mutex to protect tx and rx 71 * @tx: transmit buffer 72 * @rx: receive buffer 73 **/ 74 struct adxrs450_state { 75 struct spi_device *us; 76 struct mutex buf_lock; 77 __be32 tx ____cacheline_aligned; 78 __be32 rx; 79 80 }; 81 82 /** 83 * adxrs450_spi_read_reg_16() - read 2 bytes from a register pair 84 * @indio_dev: device associated with child of actual iio_dev 85 * @reg_address: the address of the lower of the two registers, which should be 86 * an even address, the second register's address is reg_address + 1. 87 * @val: somewhere to pass back the value read 88 **/ 89 static int adxrs450_spi_read_reg_16(struct iio_dev *indio_dev, 90 u8 reg_address, 91 u16 *val) 92 { 93 struct adxrs450_state *st = iio_priv(indio_dev); 94 u32 tx; 95 int ret; 96 struct spi_transfer xfers[] = { 97 { 98 .tx_buf = &st->tx, 99 .bits_per_word = 8, 100 .len = sizeof(st->tx), 101 .cs_change = 1, 102 }, { 103 .rx_buf = &st->rx, 104 .bits_per_word = 8, 105 .len = sizeof(st->rx), 106 }, 107 }; 108 109 mutex_lock(&st->buf_lock); 110 tx = ADXRS450_READ_DATA | (reg_address << 17); 111 112 if (!(hweight32(tx) & 1)) 113 tx |= ADXRS450_P; 114 115 st->tx = cpu_to_be32(tx); 116 ret = spi_sync_transfer(st->us, xfers, ARRAY_SIZE(xfers)); 117 if (ret) { 118 dev_err(&st->us->dev, "problem while reading 16 bit register 0x%02x\n", 119 reg_address); 120 goto error_ret; 121 } 122 123 *val = (be32_to_cpu(st->rx) >> 5) & 0xFFFF; 124 125 error_ret: 126 mutex_unlock(&st->buf_lock); 127 return ret; 128 } 129 130 /** 131 * adxrs450_spi_write_reg_16() - write 2 bytes data to a register pair 132 * @indio_dev: device associated with child of actual actual iio_dev 133 * @reg_address: the address of the lower of the two registers,which should be 134 * an even address, the second register's address is reg_address + 1. 135 * @val: value to be written. 136 **/ 137 static int adxrs450_spi_write_reg_16(struct iio_dev *indio_dev, 138 u8 reg_address, 139 u16 val) 140 { 141 struct adxrs450_state *st = iio_priv(indio_dev); 142 u32 tx; 143 int ret; 144 145 mutex_lock(&st->buf_lock); 146 tx = ADXRS450_WRITE_DATA | (reg_address << 17) | (val << 1); 147 148 if (!(hweight32(tx) & 1)) 149 tx |= ADXRS450_P; 150 151 st->tx = cpu_to_be32(tx); 152 ret = spi_write(st->us, &st->tx, sizeof(st->tx)); 153 if (ret) 154 dev_err(&st->us->dev, "problem while writing 16 bit register 0x%02x\n", 155 reg_address); 156 usleep_range(100, 1000); /* enforce sequential transfer delay 0.1ms */ 157 mutex_unlock(&st->buf_lock); 158 return ret; 159 } 160 161 /** 162 * adxrs450_spi_sensor_data() - read 2 bytes sensor data 163 * @indio_dev: device associated with child of actual iio_dev 164 * @val: somewhere to pass back the value read 165 **/ 166 static int adxrs450_spi_sensor_data(struct iio_dev *indio_dev, s16 *val) 167 { 168 struct adxrs450_state *st = iio_priv(indio_dev); 169 int ret; 170 struct spi_transfer xfers[] = { 171 { 172 .tx_buf = &st->tx, 173 .bits_per_word = 8, 174 .len = sizeof(st->tx), 175 .cs_change = 1, 176 }, { 177 .rx_buf = &st->rx, 178 .bits_per_word = 8, 179 .len = sizeof(st->rx), 180 }, 181 }; 182 183 mutex_lock(&st->buf_lock); 184 st->tx = cpu_to_be32(ADXRS450_SENSOR_DATA); 185 186 ret = spi_sync_transfer(st->us, xfers, ARRAY_SIZE(xfers)); 187 if (ret) { 188 dev_err(&st->us->dev, "Problem while reading sensor data\n"); 189 goto error_ret; 190 } 191 192 *val = (be32_to_cpu(st->rx) >> 10) & 0xFFFF; 193 194 error_ret: 195 mutex_unlock(&st->buf_lock); 196 return ret; 197 } 198 199 /** 200 * adxrs450_spi_initial() - use for initializing procedure. 201 * @st: device instance specific data 202 * @val: somewhere to pass back the value read 203 * @chk: Whether to perform fault check 204 **/ 205 static int adxrs450_spi_initial(struct adxrs450_state *st, 206 u32 *val, char chk) 207 { 208 int ret; 209 u32 tx; 210 struct spi_transfer xfers = { 211 .tx_buf = &st->tx, 212 .rx_buf = &st->rx, 213 .bits_per_word = 8, 214 .len = sizeof(st->tx), 215 }; 216 217 mutex_lock(&st->buf_lock); 218 tx = ADXRS450_SENSOR_DATA; 219 if (chk) 220 tx |= (ADXRS450_CHK | ADXRS450_P); 221 st->tx = cpu_to_be32(tx); 222 ret = spi_sync_transfer(st->us, &xfers, 1); 223 if (ret) { 224 dev_err(&st->us->dev, "Problem while reading initializing data\n"); 225 goto error_ret; 226 } 227 228 *val = be32_to_cpu(st->rx); 229 230 error_ret: 231 mutex_unlock(&st->buf_lock); 232 return ret; 233 } 234 235 /* Recommended Startup Sequence by spec */ 236 static int adxrs450_initial_setup(struct iio_dev *indio_dev) 237 { 238 u32 t; 239 u16 data; 240 int ret; 241 struct adxrs450_state *st = iio_priv(indio_dev); 242 243 msleep(ADXRS450_STARTUP_DELAY*2); 244 ret = adxrs450_spi_initial(st, &t, 1); 245 if (ret) 246 return ret; 247 if (t != 0x01) 248 dev_warn(&st->us->dev, "The initial power on response is not correct! Restart without reset?\n"); 249 250 msleep(ADXRS450_STARTUP_DELAY); 251 ret = adxrs450_spi_initial(st, &t, 0); 252 if (ret) 253 return ret; 254 255 msleep(ADXRS450_STARTUP_DELAY); 256 ret = adxrs450_spi_initial(st, &t, 0); 257 if (ret) 258 return ret; 259 if (((t & 0xff) | 0x01) != 0xff || ADXRS450_GET_ST(t) != 2) { 260 dev_err(&st->us->dev, "The second response is not correct!\n"); 261 return -EIO; 262 263 } 264 ret = adxrs450_spi_initial(st, &t, 0); 265 if (ret) 266 return ret; 267 if (((t & 0xff) | 0x01) != 0xff || ADXRS450_GET_ST(t) != 2) { 268 dev_err(&st->us->dev, "The third response is not correct!\n"); 269 return -EIO; 270 271 } 272 ret = adxrs450_spi_read_reg_16(indio_dev, ADXRS450_FAULT1, &data); 273 if (ret) 274 return ret; 275 if (data & 0x0fff) { 276 dev_err(&st->us->dev, "The device is not in normal status!\n"); 277 return -EINVAL; 278 } 279 280 return 0; 281 } 282 283 static int adxrs450_write_raw(struct iio_dev *indio_dev, 284 struct iio_chan_spec const *chan, 285 int val, 286 int val2, 287 long mask) 288 { 289 int ret; 290 switch (mask) { 291 case IIO_CHAN_INFO_CALIBBIAS: 292 if (val < -0x400 || val >= 0x400) 293 return -EINVAL; 294 ret = adxrs450_spi_write_reg_16(indio_dev, 295 ADXRS450_DNC1, val); 296 break; 297 default: 298 ret = -EINVAL; 299 break; 300 } 301 return ret; 302 } 303 304 static int adxrs450_read_raw(struct iio_dev *indio_dev, 305 struct iio_chan_spec const *chan, 306 int *val, 307 int *val2, 308 long mask) 309 { 310 int ret; 311 s16 t; 312 313 switch (mask) { 314 case IIO_CHAN_INFO_RAW: 315 switch (chan->type) { 316 case IIO_ANGL_VEL: 317 ret = adxrs450_spi_sensor_data(indio_dev, &t); 318 if (ret) 319 break; 320 *val = t; 321 ret = IIO_VAL_INT; 322 break; 323 case IIO_TEMP: 324 ret = adxrs450_spi_read_reg_16(indio_dev, 325 ADXRS450_TEMP1, &t); 326 if (ret) 327 break; 328 *val = (t >> 6) + 225; 329 ret = IIO_VAL_INT; 330 break; 331 default: 332 ret = -EINVAL; 333 break; 334 } 335 break; 336 case IIO_CHAN_INFO_SCALE: 337 switch (chan->type) { 338 case IIO_ANGL_VEL: 339 *val = 0; 340 *val2 = 218166; 341 return IIO_VAL_INT_PLUS_NANO; 342 case IIO_TEMP: 343 *val = 200; 344 *val2 = 0; 345 return IIO_VAL_INT; 346 default: 347 return -EINVAL; 348 } 349 case IIO_CHAN_INFO_QUADRATURE_CORRECTION_RAW: 350 ret = adxrs450_spi_read_reg_16(indio_dev, ADXRS450_QUAD1, &t); 351 if (ret) 352 break; 353 *val = t; 354 ret = IIO_VAL_INT; 355 break; 356 case IIO_CHAN_INFO_CALIBBIAS: 357 ret = adxrs450_spi_read_reg_16(indio_dev, ADXRS450_DNC1, &t); 358 if (ret) 359 break; 360 *val = sign_extend32(t, 9); 361 ret = IIO_VAL_INT; 362 break; 363 default: 364 ret = -EINVAL; 365 break; 366 } 367 368 return ret; 369 } 370 371 static const struct iio_chan_spec adxrs450_channels[2][2] = { 372 [ID_ADXRS450] = { 373 { 374 .type = IIO_ANGL_VEL, 375 .modified = 1, 376 .channel2 = IIO_MOD_Z, 377 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | 378 BIT(IIO_CHAN_INFO_CALIBBIAS) | 379 BIT(IIO_CHAN_INFO_QUADRATURE_CORRECTION_RAW) | 380 BIT(IIO_CHAN_INFO_SCALE), 381 }, { 382 .type = IIO_TEMP, 383 .indexed = 1, 384 .channel = 0, 385 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | 386 BIT(IIO_CHAN_INFO_SCALE), 387 } 388 }, 389 [ID_ADXRS453] = { 390 { 391 .type = IIO_ANGL_VEL, 392 .modified = 1, 393 .channel2 = IIO_MOD_Z, 394 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | 395 BIT(IIO_CHAN_INFO_SCALE) | 396 BIT(IIO_CHAN_INFO_QUADRATURE_CORRECTION_RAW), 397 }, { 398 .type = IIO_TEMP, 399 .indexed = 1, 400 .channel = 0, 401 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | 402 BIT(IIO_CHAN_INFO_SCALE), 403 } 404 }, 405 }; 406 407 static const struct iio_info adxrs450_info = { 408 .driver_module = THIS_MODULE, 409 .read_raw = &adxrs450_read_raw, 410 .write_raw = &adxrs450_write_raw, 411 }; 412 413 static int adxrs450_probe(struct spi_device *spi) 414 { 415 int ret; 416 struct adxrs450_state *st; 417 struct iio_dev *indio_dev; 418 419 /* setup the industrialio driver allocated elements */ 420 indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*st)); 421 if (!indio_dev) 422 return -ENOMEM; 423 st = iio_priv(indio_dev); 424 st->us = spi; 425 mutex_init(&st->buf_lock); 426 /* This is only used for removal purposes */ 427 spi_set_drvdata(spi, indio_dev); 428 429 indio_dev->dev.parent = &spi->dev; 430 indio_dev->info = &adxrs450_info; 431 indio_dev->modes = INDIO_DIRECT_MODE; 432 indio_dev->channels = 433 adxrs450_channels[spi_get_device_id(spi)->driver_data]; 434 indio_dev->num_channels = ARRAY_SIZE(adxrs450_channels); 435 indio_dev->name = spi->dev.driver->name; 436 437 ret = devm_iio_device_register(&spi->dev, indio_dev); 438 if (ret) 439 return ret; 440 441 /* Get the device into a sane initial state */ 442 ret = adxrs450_initial_setup(indio_dev); 443 if (ret) 444 return ret; 445 446 return 0; 447 } 448 449 static const struct spi_device_id adxrs450_id[] = { 450 {"adxrs450", ID_ADXRS450}, 451 {"adxrs453", ID_ADXRS453}, 452 {} 453 }; 454 MODULE_DEVICE_TABLE(spi, adxrs450_id); 455 456 static struct spi_driver adxrs450_driver = { 457 .driver = { 458 .name = "adxrs450", 459 .owner = THIS_MODULE, 460 }, 461 .probe = adxrs450_probe, 462 .id_table = adxrs450_id, 463 }; 464 module_spi_driver(adxrs450_driver); 465 466 MODULE_AUTHOR("Cliff Cai <cliff.cai@xxxxxxxxxx>"); 467 MODULE_DESCRIPTION("Analog Devices ADXRS450/ADXRS453 Gyroscope SPI driver"); 468 MODULE_LICENSE("GPL v2"); 469