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 94 switch (info) { 95 case IIO_CHAN_INFO_RAW: 96 reg = (u8)chan->address; 97 ret = itg3200_read_reg_s16(indio_dev, reg, val); 98 return IIO_VAL_INT; 99 case IIO_CHAN_INFO_SCALE: 100 *val = 0; 101 if (chan->type == IIO_TEMP) 102 *val2 = 1000000000/280; 103 else 104 *val2 = 1214142; /* (1 / 14,375) * (PI / 180) */ 105 return IIO_VAL_INT_PLUS_NANO; 106 case IIO_CHAN_INFO_OFFSET: 107 /* Only the temperature channel has an offset */ 108 *val = 23000; 109 return IIO_VAL_INT; 110 default: 111 return -EINVAL; 112 } 113 114 return ret; 115 } 116 117 static ssize_t itg3200_read_frequency(struct device *dev, 118 struct device_attribute *attr, char *buf) 119 { 120 struct iio_dev *indio_dev = dev_to_iio_dev(dev); 121 int ret, sps; 122 u8 val; 123 124 ret = itg3200_read_reg_8(indio_dev, ITG3200_REG_DLPF, &val); 125 if (ret) 126 return ret; 127 128 sps = (val & ITG3200_DLPF_CFG_MASK) ? 1000 : 8000; 129 130 ret = itg3200_read_reg_8(indio_dev, ITG3200_REG_SAMPLE_RATE_DIV, &val); 131 if (ret) 132 return ret; 133 134 sps /= val + 1; 135 136 return sprintf(buf, "%d\n", sps); 137 } 138 139 static ssize_t itg3200_write_frequency(struct device *dev, 140 struct device_attribute *attr, 141 const char *buf, 142 size_t len) 143 { 144 struct iio_dev *indio_dev = dev_to_iio_dev(dev); 145 unsigned val; 146 int ret; 147 u8 t; 148 149 ret = kstrtouint(buf, 10, &val); 150 if (ret) 151 return ret; 152 153 mutex_lock(&indio_dev->mlock); 154 155 ret = itg3200_read_reg_8(indio_dev, ITG3200_REG_DLPF, &t); 156 if (ret) 157 goto err_ret; 158 159 if (val == 0) { 160 ret = -EINVAL; 161 goto err_ret; 162 } 163 t = ((t & ITG3200_DLPF_CFG_MASK) ? 1000u : 8000u) / val - 1; 164 165 ret = itg3200_write_reg_8(indio_dev, ITG3200_REG_SAMPLE_RATE_DIV, t); 166 167 err_ret: 168 mutex_unlock(&indio_dev->mlock); 169 170 return ret ? ret : len; 171 } 172 173 /* 174 * Reset device and internal registers to the power-up-default settings 175 * Use the gyro clock as reference, as suggested by the datasheet 176 */ 177 static int itg3200_reset(struct iio_dev *indio_dev) 178 { 179 struct itg3200 *st = iio_priv(indio_dev); 180 int ret; 181 182 dev_dbg(&st->i2c->dev, "reset device"); 183 184 ret = itg3200_write_reg_8(indio_dev, 185 ITG3200_REG_POWER_MANAGEMENT, 186 ITG3200_RESET); 187 if (ret) { 188 dev_err(&st->i2c->dev, "error resetting device"); 189 goto error_ret; 190 } 191 192 /* Wait for PLL (1ms according to datasheet) */ 193 udelay(1500); 194 195 ret = itg3200_write_reg_8(indio_dev, 196 ITG3200_REG_IRQ_CONFIG, 197 ITG3200_IRQ_ACTIVE_HIGH | 198 ITG3200_IRQ_PUSH_PULL | 199 ITG3200_IRQ_LATCH_50US_PULSE | 200 ITG3200_IRQ_LATCH_CLEAR_ANY); 201 202 if (ret) 203 dev_err(&st->i2c->dev, "error init device"); 204 205 error_ret: 206 return ret; 207 } 208 209 /* itg3200_enable_full_scale() - Disables the digital low pass filter */ 210 static int itg3200_enable_full_scale(struct iio_dev *indio_dev) 211 { 212 u8 val; 213 int ret; 214 215 ret = itg3200_read_reg_8(indio_dev, ITG3200_REG_DLPF, &val); 216 if (ret) 217 goto err_ret; 218 219 val |= ITG3200_DLPF_FS_SEL_2000; 220 return itg3200_write_reg_8(indio_dev, ITG3200_REG_DLPF, val); 221 222 err_ret: 223 return ret; 224 } 225 226 static int itg3200_initial_setup(struct iio_dev *indio_dev) 227 { 228 struct itg3200 *st = iio_priv(indio_dev); 229 int ret; 230 u8 val; 231 232 ret = itg3200_read_reg_8(indio_dev, ITG3200_REG_ADDRESS, &val); 233 if (ret) 234 goto err_ret; 235 236 if (((val >> 1) & 0x3f) != 0x34) { 237 dev_err(&st->i2c->dev, "invalid reg value 0x%02x", val); 238 ret = -ENXIO; 239 goto err_ret; 240 } 241 242 ret = itg3200_reset(indio_dev); 243 if (ret) 244 goto err_ret; 245 246 ret = itg3200_enable_full_scale(indio_dev); 247 err_ret: 248 return ret; 249 } 250 251 #define ITG3200_ST \ 252 { .sign = 's', .realbits = 16, .storagebits = 16, .endianness = IIO_BE } 253 254 #define ITG3200_GYRO_CHAN(_mod) { \ 255 .type = IIO_ANGL_VEL, \ 256 .modified = 1, \ 257 .channel2 = IIO_MOD_ ## _mod, \ 258 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \ 259 .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE), \ 260 .address = ITG3200_REG_GYRO_ ## _mod ## OUT_H, \ 261 .scan_index = ITG3200_SCAN_GYRO_ ## _mod, \ 262 .scan_type = ITG3200_ST, \ 263 } 264 265 static const struct iio_chan_spec itg3200_channels[] = { 266 { 267 .type = IIO_TEMP, 268 .channel2 = IIO_NO_MOD, 269 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), 270 .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_OFFSET) | 271 BIT(IIO_CHAN_INFO_SCALE), 272 .address = ITG3200_REG_TEMP_OUT_H, 273 .scan_index = ITG3200_SCAN_TEMP, 274 .scan_type = ITG3200_ST, 275 }, 276 ITG3200_GYRO_CHAN(X), 277 ITG3200_GYRO_CHAN(Y), 278 ITG3200_GYRO_CHAN(Z), 279 IIO_CHAN_SOFT_TIMESTAMP(ITG3200_SCAN_ELEMENTS), 280 }; 281 282 /* IIO device attributes */ 283 static IIO_DEV_ATTR_SAMP_FREQ(S_IWUSR | S_IRUGO, itg3200_read_frequency, 284 itg3200_write_frequency); 285 286 static struct attribute *itg3200_attributes[] = { 287 &iio_dev_attr_sampling_frequency.dev_attr.attr, 288 NULL 289 }; 290 291 static const struct attribute_group itg3200_attribute_group = { 292 .attrs = itg3200_attributes, 293 }; 294 295 static const struct iio_info itg3200_info = { 296 .attrs = &itg3200_attribute_group, 297 .read_raw = &itg3200_read_raw, 298 .driver_module = THIS_MODULE, 299 }; 300 301 static const unsigned long itg3200_available_scan_masks[] = { 0xffffffff, 0x0 }; 302 303 static int itg3200_probe(struct i2c_client *client, 304 const struct i2c_device_id *id) 305 { 306 int ret; 307 struct itg3200 *st; 308 struct iio_dev *indio_dev; 309 310 dev_dbg(&client->dev, "probe I2C dev with IRQ %i", client->irq); 311 312 indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*st)); 313 if (!indio_dev) 314 return -ENOMEM; 315 316 st = iio_priv(indio_dev); 317 318 i2c_set_clientdata(client, indio_dev); 319 st->i2c = client; 320 321 indio_dev->dev.parent = &client->dev; 322 indio_dev->name = client->dev.driver->name; 323 indio_dev->channels = itg3200_channels; 324 indio_dev->num_channels = ARRAY_SIZE(itg3200_channels); 325 indio_dev->available_scan_masks = itg3200_available_scan_masks; 326 indio_dev->info = &itg3200_info; 327 indio_dev->modes = INDIO_DIRECT_MODE; 328 329 ret = itg3200_buffer_configure(indio_dev); 330 if (ret) 331 return ret; 332 333 if (client->irq) { 334 ret = itg3200_probe_trigger(indio_dev); 335 if (ret) 336 goto error_unconfigure_buffer; 337 } 338 339 ret = itg3200_initial_setup(indio_dev); 340 if (ret) 341 goto error_remove_trigger; 342 343 ret = iio_device_register(indio_dev); 344 if (ret) 345 goto error_remove_trigger; 346 347 return 0; 348 349 error_remove_trigger: 350 if (client->irq) 351 itg3200_remove_trigger(indio_dev); 352 error_unconfigure_buffer: 353 itg3200_buffer_unconfigure(indio_dev); 354 return ret; 355 } 356 357 static int itg3200_remove(struct i2c_client *client) 358 { 359 struct iio_dev *indio_dev = i2c_get_clientdata(client); 360 361 iio_device_unregister(indio_dev); 362 363 if (client->irq) 364 itg3200_remove_trigger(indio_dev); 365 366 itg3200_buffer_unconfigure(indio_dev); 367 368 return 0; 369 } 370 371 static const struct i2c_device_id itg3200_id[] = { 372 { "itg3200", 0 }, 373 { } 374 }; 375 MODULE_DEVICE_TABLE(i2c, itg3200_id); 376 377 static struct i2c_driver itg3200_driver = { 378 .driver = { 379 .owner = THIS_MODULE, 380 .name = "itg3200", 381 }, 382 .id_table = itg3200_id, 383 .probe = itg3200_probe, 384 .remove = itg3200_remove, 385 }; 386 387 module_i2c_driver(itg3200_driver); 388 389 MODULE_AUTHOR("Christian Strobel <christian.strobel@iis.fraunhofer.de>"); 390 MODULE_DESCRIPTION("ITG3200 Gyroscope I2C driver"); 391 MODULE_LICENSE("GPL v2"); 392