Jonathan Cameron | 3a84331 | 2011-10-14 16:34:13 +0100 | [diff] [blame] | 1 | /** |
| 2 | * Copyright (c) 2011 Jonathan Cameron |
| 3 | * |
| 4 | * This program is free software; you can redistribute it and/or modify it |
| 5 | * under the terms of the GNU General Public License version 2 as published by |
| 6 | * the Free Software Foundation. |
| 7 | * |
| 8 | * A reference industrial I/O driver to illustrate the functionality available. |
| 9 | * |
| 10 | * There are numerous real drivers to illustrate the finer points. |
| 11 | * The purpose of this driver is to provide a driver with far more comments |
| 12 | * and explanatory notes than any 'real' driver would have. |
| 13 | * Anyone starting out writing an IIO driver should first make sure they |
| 14 | * understand all of this driver except those bits specifically marked |
| 15 | * as being present to allow us to 'fake' the presence of hardware. |
| 16 | */ |
| 17 | #include <linux/kernel.h> |
| 18 | #include <linux/slab.h> |
| 19 | #include <linux/module.h> |
| 20 | #include <linux/moduleparam.h> |
| 21 | |
| 22 | #include "iio.h" |
Jonathan Cameron | e647700 | 2011-10-14 16:34:14 +0100 | [diff] [blame] | 23 | #include "sysfs.h" |
Jonathan Cameron | af5046a | 2011-10-26 17:41:32 +0100 | [diff] [blame] | 24 | #include "events.h" |
| 25 | #include "buffer.h" |
Jonathan Cameron | e647700 | 2011-10-14 16:34:14 +0100 | [diff] [blame] | 26 | #include "iio_simple_dummy.h" |
Jonathan Cameron | 3a84331 | 2011-10-14 16:34:13 +0100 | [diff] [blame] | 27 | |
| 28 | /* |
| 29 | * A few elements needed to fake a bus for this driver |
| 30 | * Note instances parmeter controls how many of these |
| 31 | * dummy devices are registered. |
| 32 | */ |
| 33 | static unsigned instances = 1; |
| 34 | module_param(instances, int, 0); |
| 35 | |
| 36 | /* Pointer array used to fake bus elements */ |
| 37 | static struct iio_dev **iio_dummy_devs; |
| 38 | |
| 39 | /* Fake a name for the part number, usually obtained from the id table */ |
| 40 | static const char *iio_dummy_part_number = "iio_dummy_part_no"; |
| 41 | |
| 42 | /** |
| 43 | * struct iio_dummy_accel_calibscale - realworld to register mapping |
| 44 | * @val: first value in read_raw - here integer part. |
| 45 | * @val2: second value in read_raw etc - here micro part. |
| 46 | * @regval: register value - magic device specific numbers. |
| 47 | */ |
| 48 | struct iio_dummy_accel_calibscale { |
| 49 | int val; |
| 50 | int val2; |
| 51 | int regval; /* what would be written to hardware */ |
| 52 | }; |
| 53 | |
| 54 | static const struct iio_dummy_accel_calibscale dummy_scales[] = { |
| 55 | { 0, 100, 0x8 }, /* 0.000100 */ |
| 56 | { 0, 133, 0x7 }, /* 0.000133 */ |
| 57 | { 733, 13, 0x9 }, /* 733.00013 */ |
| 58 | }; |
| 59 | |
Jonathan Cameron | 3a84331 | 2011-10-14 16:34:13 +0100 | [diff] [blame] | 60 | /* |
| 61 | * iio_dummy_channels - Description of available channels |
| 62 | * |
| 63 | * This array of structures tells the IIO core about what the device |
| 64 | * actually provides for a given channel. |
| 65 | */ |
| 66 | static struct iio_chan_spec iio_dummy_channels[] = { |
| 67 | /* indexed ADC channel in_voltage0_raw etc */ |
| 68 | { |
| 69 | .type = IIO_VOLTAGE, |
| 70 | /* Channel has a numeric index of 0 */ |
| 71 | .indexed = 1, |
| 72 | .channel = 0, |
| 73 | /* What other information is available? */ |
| 74 | .info_mask = |
| 75 | /* |
| 76 | * in_voltage0_offset |
| 77 | * Offset for userspace to apply prior to scale |
| 78 | * when converting to standard units (microvolts) |
| 79 | */ |
Jonathan Cameron | c8a9f80 | 2011-10-26 17:41:36 +0100 | [diff] [blame^] | 80 | IIO_CHAN_INFO_OFFSET_SEPARATE_BIT | |
Jonathan Cameron | 3a84331 | 2011-10-14 16:34:13 +0100 | [diff] [blame] | 81 | /* |
| 82 | * in_voltage0_scale |
| 83 | * Multipler for userspace to apply post offset |
| 84 | * when converting to standard units (microvolts) |
| 85 | */ |
Jonathan Cameron | c8a9f80 | 2011-10-26 17:41:36 +0100 | [diff] [blame^] | 86 | IIO_CHAN_INFO_SCALE_SEPARATE_BIT, |
Jonathan Cameron | 9ad2e2e | 2011-10-14 16:34:15 +0100 | [diff] [blame] | 87 | /* The ordering of elements in the buffer via an enum */ |
| 88 | .scan_index = voltage0, |
| 89 | .scan_type = { /* Description of storage in buffer */ |
| 90 | .sign = 'u', /* unsigned */ |
| 91 | .realbits = 13, /* 13 bits */ |
| 92 | .storagebits = 16, /* 16 bits used for storage */ |
| 93 | .shift = 0, /* zero shift */ |
| 94 | }, |
Jonathan Cameron | e647700 | 2011-10-14 16:34:14 +0100 | [diff] [blame] | 95 | #ifdef CONFIG_IIO_SIMPLE_DUMMY_EVENTS |
| 96 | /* |
| 97 | * simple event - triggered when value rises above |
| 98 | * a threshold |
| 99 | */ |
| 100 | .event_mask = IIO_EV_BIT(IIO_EV_TYPE_THRESH, |
| 101 | IIO_EV_DIR_RISING), |
| 102 | #endif /* CONFIG_IIO_SIMPLE_DUMMY_EVENTS */ |
Jonathan Cameron | 3a84331 | 2011-10-14 16:34:13 +0100 | [diff] [blame] | 103 | }, |
| 104 | /* Differential ADC channel in_voltage1-voltage2_raw etc*/ |
| 105 | { |
| 106 | .type = IIO_VOLTAGE, |
| 107 | .differential = 1, |
| 108 | /* |
| 109 | * Indexing for differential channels uses channel |
| 110 | * for the positive part, channel2 for the negative. |
| 111 | */ |
| 112 | .indexed = 1, |
| 113 | .channel = 1, |
| 114 | .channel2 = 2, |
| 115 | .info_mask = |
| 116 | /* |
| 117 | * in_voltage-voltage_scale |
| 118 | * Shared version of scale - shared by differential |
| 119 | * input channels of type IIO_VOLTAGE. |
| 120 | */ |
Jonathan Cameron | c8a9f80 | 2011-10-26 17:41:36 +0100 | [diff] [blame^] | 121 | IIO_CHAN_INFO_SCALE_SHARED_BIT, |
Jonathan Cameron | 9ad2e2e | 2011-10-14 16:34:15 +0100 | [diff] [blame] | 122 | .scan_index = diffvoltage1m2, |
| 123 | .scan_type = { /* Description of storage in buffer */ |
| 124 | .sign = 's', /* signed */ |
| 125 | .realbits = 12, /* 12 bits */ |
| 126 | .storagebits = 16, /* 16 bits used for storage */ |
| 127 | .shift = 0, /* zero shift */ |
| 128 | }, |
Jonathan Cameron | 3a84331 | 2011-10-14 16:34:13 +0100 | [diff] [blame] | 129 | }, |
| 130 | /* Differential ADC channel in_voltage3-voltage4_raw etc*/ |
| 131 | { |
| 132 | .type = IIO_VOLTAGE, |
| 133 | .differential = 1, |
| 134 | .indexed = 1, |
| 135 | .channel = 3, |
| 136 | .channel2 = 4, |
| 137 | .info_mask = |
Jonathan Cameron | c8a9f80 | 2011-10-26 17:41:36 +0100 | [diff] [blame^] | 138 | IIO_CHAN_INFO_SCALE_SHARED_BIT, |
Jonathan Cameron | 9ad2e2e | 2011-10-14 16:34:15 +0100 | [diff] [blame] | 139 | .scan_index = diffvoltage3m4, |
| 140 | .scan_type = { |
| 141 | .sign = 's', |
| 142 | .realbits = 11, |
| 143 | .storagebits = 16, |
| 144 | .shift = 0, |
| 145 | }, |
Jonathan Cameron | 3a84331 | 2011-10-14 16:34:13 +0100 | [diff] [blame] | 146 | }, |
| 147 | /* |
| 148 | * 'modified' (i.e. axis specified) acceleration channel |
| 149 | * in_accel_z_raw |
| 150 | */ |
| 151 | { |
| 152 | .type = IIO_ACCEL, |
| 153 | .modified = 1, |
| 154 | /* Channel 2 is use for modifiers */ |
| 155 | .channel2 = IIO_MOD_X, |
| 156 | .info_mask = |
| 157 | /* |
| 158 | * Internal bias correction value. Applied |
| 159 | * by the hardware or driver prior to userspace |
| 160 | * seeing the readings. Typically part of hardware |
| 161 | * calibration. |
| 162 | */ |
Jonathan Cameron | c8a9f80 | 2011-10-26 17:41:36 +0100 | [diff] [blame^] | 163 | IIO_CHAN_INFO_CALIBBIAS_SEPARATE_BIT, |
Jonathan Cameron | 9ad2e2e | 2011-10-14 16:34:15 +0100 | [diff] [blame] | 164 | .scan_index = accelx, |
| 165 | .scan_type = { /* Description of storage in buffer */ |
| 166 | .sign = 's', /* signed */ |
| 167 | .realbits = 16, /* 12 bits */ |
| 168 | .storagebits = 16, /* 16 bits used for storage */ |
| 169 | .shift = 0, /* zero shift */ |
| 170 | }, |
| 171 | }, |
| 172 | /* |
| 173 | * Convenience macro for timestamps. 4 is the index in |
| 174 | * the buffer. |
| 175 | */ |
| 176 | IIO_CHAN_SOFT_TIMESTAMP(4), |
| 177 | /* DAC channel out_voltage0_raw */ |
| 178 | { |
| 179 | .type = IIO_VOLTAGE, |
| 180 | .output = 1, |
| 181 | .indexed = 1, |
| 182 | .channel = 0, |
Jonathan Cameron | 3a84331 | 2011-10-14 16:34:13 +0100 | [diff] [blame] | 183 | }, |
| 184 | }; |
| 185 | |
| 186 | /** |
| 187 | * iio_dummy_read_raw() - data read function. |
| 188 | * @indio_dev: the struct iio_dev associated with this device instance |
| 189 | * @chan: the channel whose data is to be read |
| 190 | * @val: first element of returned value (typically INT) |
| 191 | * @val2: second element of returned value (typically MICRO) |
| 192 | * @mask: what we actually want to read. 0 is the channel, everything else |
| 193 | * is as per the info_mask in iio_chan_spec. |
| 194 | */ |
| 195 | static int iio_dummy_read_raw(struct iio_dev *indio_dev, |
| 196 | struct iio_chan_spec const *chan, |
| 197 | int *val, |
| 198 | int *val2, |
| 199 | long mask) |
| 200 | { |
| 201 | struct iio_dummy_state *st = iio_priv(indio_dev); |
| 202 | int ret = -EINVAL; |
| 203 | |
| 204 | mutex_lock(&st->lock); |
| 205 | switch (mask) { |
| 206 | case 0: /* magic value - channel value read */ |
| 207 | switch (chan->type) { |
| 208 | case IIO_VOLTAGE: |
| 209 | if (chan->output) { |
| 210 | /* Set integer part to cached value */ |
| 211 | *val = st->dac_val; |
| 212 | ret = IIO_VAL_INT; |
| 213 | } else if (chan->differential) { |
| 214 | if (chan->channel == 1) |
| 215 | *val = st->differential_adc_val[0]; |
| 216 | else |
| 217 | *val = st->differential_adc_val[1]; |
| 218 | ret = IIO_VAL_INT; |
| 219 | } else { |
| 220 | *val = st->single_ended_adc_val; |
| 221 | ret = IIO_VAL_INT; |
| 222 | } |
| 223 | break; |
| 224 | case IIO_ACCEL: |
| 225 | *val = st->accel_val; |
| 226 | ret = IIO_VAL_INT; |
| 227 | break; |
| 228 | default: |
| 229 | break; |
| 230 | } |
| 231 | break; |
Jonathan Cameron | c8a9f80 | 2011-10-26 17:41:36 +0100 | [diff] [blame^] | 232 | case IIO_CHAN_INFO_OFFSET: |
Jonathan Cameron | 3a84331 | 2011-10-14 16:34:13 +0100 | [diff] [blame] | 233 | /* only single ended adc -> 7 */ |
| 234 | *val = 7; |
| 235 | ret = IIO_VAL_INT; |
| 236 | break; |
Jonathan Cameron | c8a9f80 | 2011-10-26 17:41:36 +0100 | [diff] [blame^] | 237 | case IIO_CHAN_INFO_SCALE: |
| 238 | switch (chan->differential) { |
| 239 | case 0: |
| 240 | /* only single ended adc -> 0.001333 */ |
| 241 | *val = 0; |
| 242 | *val2 = 1333; |
| 243 | ret = IIO_VAL_INT_PLUS_MICRO; |
| 244 | break; |
| 245 | case 1: |
| 246 | /* all differential adc channels -> 0.000001344 */ |
| 247 | *val = 0; |
| 248 | *val2 = 1344; |
| 249 | ret = IIO_VAL_INT_PLUS_NANO; |
| 250 | } |
Jonathan Cameron | 3a84331 | 2011-10-14 16:34:13 +0100 | [diff] [blame] | 251 | break; |
Jonathan Cameron | c8a9f80 | 2011-10-26 17:41:36 +0100 | [diff] [blame^] | 252 | case IIO_CHAN_INFO_CALIBBIAS: |
Jonathan Cameron | 3a84331 | 2011-10-14 16:34:13 +0100 | [diff] [blame] | 253 | /* only the acceleration axis - read from cache */ |
| 254 | *val = st->accel_calibbias; |
| 255 | ret = IIO_VAL_INT; |
| 256 | break; |
Jonathan Cameron | c8a9f80 | 2011-10-26 17:41:36 +0100 | [diff] [blame^] | 257 | case IIO_CHAN_INFO_CALIBSCALE: |
Jonathan Cameron | 3a84331 | 2011-10-14 16:34:13 +0100 | [diff] [blame] | 258 | *val = st->accel_calibscale->val; |
| 259 | *val2 = st->accel_calibscale->val2; |
| 260 | ret = IIO_VAL_INT_PLUS_MICRO; |
| 261 | break; |
| 262 | default: |
| 263 | break; |
| 264 | } |
| 265 | mutex_unlock(&st->lock); |
| 266 | return ret; |
| 267 | } |
| 268 | |
| 269 | /** |
| 270 | * iio_dummy_write_raw() - data write function. |
| 271 | * @indio_dev: the struct iio_dev associated with this device instance |
| 272 | * @chan: the channel whose data is to be read |
| 273 | * @val: first element of returned value (typically INT) |
| 274 | * @val2: second element of returned value (typically MICRO) |
| 275 | * @mask: what we actually want to read. 0 is the channel, everything else |
| 276 | * is as per the info_mask in iio_chan_spec. |
| 277 | * |
| 278 | * Note that all raw writes are assumed IIO_VAL_INT and info mask elements |
| 279 | * are assumed to be IIO_INT_PLUS_MICRO unless the callback write_raw_get_fmt |
| 280 | * in struct iio_info is provided by the driver. |
| 281 | */ |
| 282 | static int iio_dummy_write_raw(struct iio_dev *indio_dev, |
| 283 | struct iio_chan_spec const *chan, |
| 284 | int val, |
| 285 | int val2, |
| 286 | long mask) |
| 287 | { |
| 288 | int i; |
| 289 | int ret = 0; |
| 290 | struct iio_dummy_state *st = iio_priv(indio_dev); |
| 291 | |
| 292 | switch (mask) { |
| 293 | case 0: |
| 294 | if (chan->output == 0) |
| 295 | return -EINVAL; |
| 296 | |
| 297 | /* Locking not required as writing single value */ |
| 298 | mutex_lock(&st->lock); |
| 299 | st->dac_val = val; |
| 300 | mutex_unlock(&st->lock); |
| 301 | return 0; |
Jonathan Cameron | c8a9f80 | 2011-10-26 17:41:36 +0100 | [diff] [blame^] | 302 | case IIO_CHAN_INFO_CALIBBIAS: |
Jonathan Cameron | 3a84331 | 2011-10-14 16:34:13 +0100 | [diff] [blame] | 303 | mutex_lock(&st->lock); |
| 304 | /* Compare against table - hard matching here */ |
| 305 | for (i = 0; i < ARRAY_SIZE(dummy_scales); i++) |
| 306 | if (val == dummy_scales[i].val && |
| 307 | val2 == dummy_scales[i].val2) |
| 308 | break; |
| 309 | if (i == ARRAY_SIZE(dummy_scales)) |
| 310 | ret = -EINVAL; |
| 311 | else |
| 312 | st->accel_calibscale = &dummy_scales[i]; |
| 313 | mutex_unlock(&st->lock); |
| 314 | return ret; |
| 315 | default: |
| 316 | return -EINVAL; |
| 317 | } |
| 318 | } |
| 319 | |
| 320 | /* |
| 321 | * Device type specific information. |
| 322 | */ |
| 323 | static const struct iio_info iio_dummy_info = { |
| 324 | .driver_module = THIS_MODULE, |
| 325 | .read_raw = &iio_dummy_read_raw, |
| 326 | .write_raw = &iio_dummy_write_raw, |
Jonathan Cameron | e647700 | 2011-10-14 16:34:14 +0100 | [diff] [blame] | 327 | #ifdef CONFIG_IIO_SIMPLE_DUMMY_EVENTS |
| 328 | .read_event_config = &iio_simple_dummy_read_event_config, |
| 329 | .write_event_config = &iio_simple_dummy_write_event_config, |
| 330 | .read_event_value = &iio_simple_dummy_read_event_value, |
| 331 | .write_event_value = &iio_simple_dummy_write_event_value, |
| 332 | #endif /* CONFIG_IIO_SIMPLE_DUMMY_EVENTS */ |
Jonathan Cameron | 3a84331 | 2011-10-14 16:34:13 +0100 | [diff] [blame] | 333 | }; |
| 334 | |
| 335 | /** |
| 336 | * iio_dummy_init_device() - device instance specific init |
| 337 | * @indio_dev: the iio device structure |
| 338 | * |
| 339 | * Most drivers have one of these to set up default values, |
| 340 | * reset the device to known state etc. |
| 341 | */ |
| 342 | static int iio_dummy_init_device(struct iio_dev *indio_dev) |
| 343 | { |
| 344 | struct iio_dummy_state *st = iio_priv(indio_dev); |
| 345 | |
| 346 | st->dac_val = 0; |
| 347 | st->single_ended_adc_val = 73; |
| 348 | st->differential_adc_val[0] = 33; |
| 349 | st->differential_adc_val[1] = -34; |
| 350 | st->accel_val = 34; |
| 351 | st->accel_calibbias = -7; |
| 352 | st->accel_calibscale = &dummy_scales[0]; |
| 353 | |
| 354 | return 0; |
| 355 | } |
| 356 | |
| 357 | /** |
| 358 | * iio_dummy_probe() - device instance probe |
| 359 | * @index: an id number for this instance. |
| 360 | * |
| 361 | * Arguments are bus type specific. |
| 362 | * I2C: iio_dummy_probe(struct i2c_client *client, |
| 363 | * const struct i2c_device_id *id) |
| 364 | * SPI: iio_dummy_probe(struct spi_device *spi) |
| 365 | */ |
| 366 | static int __devinit iio_dummy_probe(int index) |
| 367 | { |
| 368 | int ret; |
| 369 | struct iio_dev *indio_dev; |
| 370 | struct iio_dummy_state *st; |
| 371 | |
| 372 | /* |
| 373 | * Allocate an IIO device. |
| 374 | * |
| 375 | * This structure contains all generic state |
| 376 | * information about the device instance. |
| 377 | * It also has a region (accessed by iio_priv() |
| 378 | * for chip specific state information. |
| 379 | */ |
| 380 | indio_dev = iio_allocate_device(sizeof(*st)); |
| 381 | if (indio_dev == NULL) { |
| 382 | ret = -ENOMEM; |
| 383 | goto error_ret; |
| 384 | } |
| 385 | |
| 386 | st = iio_priv(indio_dev); |
| 387 | mutex_init(&st->lock); |
| 388 | |
| 389 | iio_dummy_init_device(indio_dev); |
| 390 | /* |
| 391 | * With hardware: Set the parent device. |
| 392 | * indio_dev->dev.parent = &spi->dev; |
| 393 | * indio_dev->dev.parent = &client->dev; |
| 394 | */ |
| 395 | |
| 396 | /* |
| 397 | * Make the iio_dev struct available to remove function. |
| 398 | * Bus equivalents |
| 399 | * i2c_set_clientdata(client, indio_dev); |
| 400 | * spi_set_drvdata(spi, indio_dev); |
| 401 | */ |
| 402 | iio_dummy_devs[index] = indio_dev; |
| 403 | |
| 404 | |
| 405 | /* |
| 406 | * Set the device name. |
| 407 | * |
| 408 | * This is typically a part number and obtained from the module |
| 409 | * id table. |
| 410 | * e.g. for i2c and spi: |
| 411 | * indio_dev->name = id->name; |
| 412 | * indio_dev->name = spi_get_device_id(spi)->name; |
| 413 | */ |
| 414 | indio_dev->name = iio_dummy_part_number; |
| 415 | |
| 416 | /* Provide description of available channels */ |
| 417 | indio_dev->channels = iio_dummy_channels; |
| 418 | indio_dev->num_channels = ARRAY_SIZE(iio_dummy_channels); |
| 419 | |
| 420 | /* |
| 421 | * Provide device type specific interface functions and |
| 422 | * constant data. |
| 423 | */ |
| 424 | indio_dev->info = &iio_dummy_info; |
| 425 | |
| 426 | /* Specify that device provides sysfs type interfaces */ |
| 427 | indio_dev->modes = INDIO_DIRECT_MODE; |
| 428 | |
Jonathan Cameron | e647700 | 2011-10-14 16:34:14 +0100 | [diff] [blame] | 429 | ret = iio_simple_dummy_events_register(indio_dev); |
Jonathan Cameron | 3a84331 | 2011-10-14 16:34:13 +0100 | [diff] [blame] | 430 | if (ret < 0) |
| 431 | goto error_free_device; |
Jonathan Cameron | 9ad2e2e | 2011-10-14 16:34:15 +0100 | [diff] [blame] | 432 | |
| 433 | /* Configure buffered capture support. */ |
| 434 | ret = iio_simple_dummy_configure_buffer(indio_dev); |
Jonathan Cameron | e647700 | 2011-10-14 16:34:14 +0100 | [diff] [blame] | 435 | if (ret < 0) |
| 436 | goto error_unregister_events; |
Jonathan Cameron | 3a84331 | 2011-10-14 16:34:13 +0100 | [diff] [blame] | 437 | |
Jonathan Cameron | 9ad2e2e | 2011-10-14 16:34:15 +0100 | [diff] [blame] | 438 | /* |
| 439 | * Register the channels with the buffer, but avoid the output |
| 440 | * channel being registered by reducing the number of channels by 1. |
| 441 | */ |
| 442 | ret = iio_buffer_register(indio_dev, iio_dummy_channels, 5); |
| 443 | if (ret < 0) |
| 444 | goto error_unconfigure_buffer; |
| 445 | |
| 446 | ret = iio_device_register(indio_dev); |
| 447 | if (ret < 0) |
| 448 | goto error_unregister_buffer; |
| 449 | |
Jonathan Cameron | 3a84331 | 2011-10-14 16:34:13 +0100 | [diff] [blame] | 450 | return 0; |
Jonathan Cameron | 9ad2e2e | 2011-10-14 16:34:15 +0100 | [diff] [blame] | 451 | error_unregister_buffer: |
| 452 | iio_buffer_unregister(indio_dev); |
| 453 | error_unconfigure_buffer: |
| 454 | iio_simple_dummy_unconfigure_buffer(indio_dev); |
Jonathan Cameron | e647700 | 2011-10-14 16:34:14 +0100 | [diff] [blame] | 455 | error_unregister_events: |
| 456 | iio_simple_dummy_events_unregister(indio_dev); |
Jonathan Cameron | 3a84331 | 2011-10-14 16:34:13 +0100 | [diff] [blame] | 457 | error_free_device: |
| 458 | /* Note free device should only be called, before registration |
| 459 | * has succeeded. */ |
| 460 | iio_free_device(indio_dev); |
| 461 | error_ret: |
| 462 | return ret; |
| 463 | } |
| 464 | |
| 465 | /** |
| 466 | * iio_dummy_remove() - device instance removal function |
| 467 | * @index: device index. |
| 468 | * |
| 469 | * Parameters follow those of iio_dummy_probe for buses. |
| 470 | */ |
| 471 | static int iio_dummy_remove(int index) |
| 472 | { |
Jonathan Cameron | e647700 | 2011-10-14 16:34:14 +0100 | [diff] [blame] | 473 | int ret; |
Jonathan Cameron | 3a84331 | 2011-10-14 16:34:13 +0100 | [diff] [blame] | 474 | /* |
| 475 | * Get a pointer to the device instance iio_dev structure |
| 476 | * from the bus subsystem. E.g. |
| 477 | * struct iio_dev *indio_dev = i2c_get_clientdata(client); |
| 478 | * struct iio_dev *indio_dev = spi_get_drvdata(spi); |
| 479 | */ |
| 480 | struct iio_dev *indio_dev = iio_dummy_devs[index]; |
| 481 | |
Jonathan Cameron | e647700 | 2011-10-14 16:34:14 +0100 | [diff] [blame] | 482 | |
Jonathan Cameron | 3a84331 | 2011-10-14 16:34:13 +0100 | [diff] [blame] | 483 | /* Unregister the device */ |
| 484 | iio_device_unregister(indio_dev); |
| 485 | |
| 486 | /* Device specific code to power down etc */ |
| 487 | |
Jonathan Cameron | 9ad2e2e | 2011-10-14 16:34:15 +0100 | [diff] [blame] | 488 | /* Buffered capture related cleanup */ |
| 489 | iio_buffer_unregister(indio_dev); |
| 490 | iio_simple_dummy_unconfigure_buffer(indio_dev); |
Jonathan Cameron | e647700 | 2011-10-14 16:34:14 +0100 | [diff] [blame] | 491 | |
| 492 | ret = iio_simple_dummy_events_unregister(indio_dev); |
| 493 | if (ret) |
| 494 | goto error_ret; |
| 495 | |
Jonathan Cameron | 3a84331 | 2011-10-14 16:34:13 +0100 | [diff] [blame] | 496 | /* Free all structures */ |
| 497 | iio_free_device(indio_dev); |
| 498 | |
Jonathan Cameron | e647700 | 2011-10-14 16:34:14 +0100 | [diff] [blame] | 499 | error_ret: |
| 500 | return ret; |
Jonathan Cameron | 3a84331 | 2011-10-14 16:34:13 +0100 | [diff] [blame] | 501 | } |
| 502 | |
| 503 | /** |
| 504 | * iio_dummy_init() - device driver registration |
| 505 | * |
| 506 | * Varies depending on bus type of the device. As there is no device |
| 507 | * here, call probe directly. For information on device registration |
| 508 | * i2c: |
| 509 | * Documentation/i2c/writing-clients |
| 510 | * spi: |
| 511 | * Documentation/spi/spi-summary |
| 512 | */ |
| 513 | static __init int iio_dummy_init(void) |
| 514 | { |
| 515 | int i, ret; |
| 516 | if (instances > 10) { |
| 517 | instances = 1; |
| 518 | return -EINVAL; |
| 519 | } |
| 520 | /* Fake a bus */ |
| 521 | iio_dummy_devs = kzalloc(sizeof(*iio_dummy_devs)*instances, GFP_KERNEL); |
| 522 | /* Here we have no actual device so call probe */ |
| 523 | for (i = 0; i < instances; i++) { |
| 524 | ret = iio_dummy_probe(i); |
| 525 | if (ret < 0) |
| 526 | return ret; |
| 527 | } |
| 528 | return 0; |
| 529 | } |
| 530 | module_init(iio_dummy_init); |
| 531 | |
| 532 | /** |
| 533 | * iio_dummy_exit() - device driver removal |
| 534 | * |
| 535 | * Varies depending on bus type of the device. |
| 536 | * As there is no device here, call remove directly. |
| 537 | */ |
| 538 | static __exit void iio_dummy_exit(void) |
| 539 | { |
| 540 | int i; |
| 541 | for (i = 0; i < instances; i++) |
| 542 | iio_dummy_remove(i); |
| 543 | kfree(iio_dummy_devs); |
| 544 | } |
| 545 | module_exit(iio_dummy_exit); |
| 546 | |
| 547 | MODULE_AUTHOR("Jonathan Cameron <jic23@cam.ac.uk>"); |
| 548 | MODULE_DESCRIPTION("IIO dummy driver"); |
| 549 | MODULE_LICENSE("GPL v2"); |