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