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3a84331d JC |
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 | ||
06458e27 JC |
22 | #include <linux/iio/iio.h> |
23 | #include <linux/iio/sysfs.h> | |
24 | #include <linux/iio/events.h> | |
25 | #include <linux/iio/buffer.h> | |
e6477000 | 26 | #include "iio_simple_dummy.h" |
3a84331d JC |
27 | |
28 | /* | |
29 | * A few elements needed to fake a bus for this driver | |
25c38aa3 | 30 | * Note instances parameter controls how many of these |
3a84331d JC |
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 */ | |
569c4ac2 | 57 | { 733, 13, 0x9 }, /* 733.000013 */ |
3a84331d JC |
58 | }; |
59 | ||
bda624b0 LPC |
60 | #ifdef CONFIG_IIO_SIMPLE_DUMMY_EVENTS |
61 | ||
62 | /* | |
63 | * simple event - triggered when value rises above | |
64 | * a threshold | |
65 | */ | |
66 | static const struct iio_event_spec iio_dummy_event = { | |
67 | .type = IIO_EV_TYPE_THRESH, | |
68 | .dir = IIO_EV_DIR_RISING, | |
69 | .mask_separate = BIT(IIO_EV_INFO_VALUE) | BIT(IIO_EV_INFO_ENABLE), | |
70 | }; | |
71 | ||
72 | #endif | |
73 | ||
3a84331d JC |
74 | /* |
75 | * iio_dummy_channels - Description of available channels | |
76 | * | |
77 | * This array of structures tells the IIO core about what the device | |
78 | * actually provides for a given channel. | |
79 | */ | |
f4e4b955 | 80 | static const struct iio_chan_spec iio_dummy_channels[] = { |
3a84331d JC |
81 | /* indexed ADC channel in_voltage0_raw etc */ |
82 | { | |
83 | .type = IIO_VOLTAGE, | |
84 | /* Channel has a numeric index of 0 */ | |
85 | .indexed = 1, | |
86 | .channel = 0, | |
87 | /* What other information is available? */ | |
fa357a6a | 88 | .info_mask_separate = |
41fd935b LPC |
89 | /* |
90 | * in_voltage0_raw | |
91 | * Raw (unscaled no bias removal etc) measurement | |
92 | * from the device. | |
93 | */ | |
fa357a6a | 94 | BIT(IIO_CHAN_INFO_RAW) | |
3a84331d JC |
95 | /* |
96 | * in_voltage0_offset | |
97 | * Offset for userspace to apply prior to scale | |
98 | * when converting to standard units (microvolts) | |
99 | */ | |
fa357a6a | 100 | BIT(IIO_CHAN_INFO_OFFSET) | |
3a84331d JC |
101 | /* |
102 | * in_voltage0_scale | |
103 | * Multipler for userspace to apply post offset | |
104 | * when converting to standard units (microvolts) | |
105 | */ | |
fa357a6a | 106 | BIT(IIO_CHAN_INFO_SCALE), |
6a63aa0a JC |
107 | /* |
108 | * sampling_frequency | |
109 | * The frequency in Hz at which the channels are sampled | |
110 | */ | |
111 | .info_mask_shared_by_dir = BIT(IIO_CHAN_INFO_SAMP_FREQ), | |
9ad2e2e1 JC |
112 | /* The ordering of elements in the buffer via an enum */ |
113 | .scan_index = voltage0, | |
114 | .scan_type = { /* Description of storage in buffer */ | |
115 | .sign = 'u', /* unsigned */ | |
116 | .realbits = 13, /* 13 bits */ | |
117 | .storagebits = 16, /* 16 bits used for storage */ | |
118 | .shift = 0, /* zero shift */ | |
119 | }, | |
e6477000 | 120 | #ifdef CONFIG_IIO_SIMPLE_DUMMY_EVENTS |
bda624b0 LPC |
121 | .event_spec = &iio_dummy_event, |
122 | .num_event_specs = 1, | |
e6477000 | 123 | #endif /* CONFIG_IIO_SIMPLE_DUMMY_EVENTS */ |
3a84331d JC |
124 | }, |
125 | /* Differential ADC channel in_voltage1-voltage2_raw etc*/ | |
126 | { | |
127 | .type = IIO_VOLTAGE, | |
128 | .differential = 1, | |
129 | /* | |
130 | * Indexing for differential channels uses channel | |
131 | * for the positive part, channel2 for the negative. | |
132 | */ | |
133 | .indexed = 1, | |
134 | .channel = 1, | |
135 | .channel2 = 2, | |
41fd935b LPC |
136 | /* |
137 | * in_voltage1-voltage2_raw | |
138 | * Raw (unscaled no bias removal etc) measurement | |
139 | * from the device. | |
140 | */ | |
fa357a6a | 141 | .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), |
3a84331d JC |
142 | /* |
143 | * in_voltage-voltage_scale | |
144 | * Shared version of scale - shared by differential | |
145 | * input channels of type IIO_VOLTAGE. | |
146 | */ | |
fa357a6a | 147 | .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE), |
6a63aa0a JC |
148 | /* |
149 | * sampling_frequency | |
150 | * The frequency in Hz at which the channels are sampled | |
151 | */ | |
9ad2e2e1 JC |
152 | .scan_index = diffvoltage1m2, |
153 | .scan_type = { /* Description of storage in buffer */ | |
154 | .sign = 's', /* signed */ | |
155 | .realbits = 12, /* 12 bits */ | |
156 | .storagebits = 16, /* 16 bits used for storage */ | |
157 | .shift = 0, /* zero shift */ | |
158 | }, | |
3a84331d JC |
159 | }, |
160 | /* Differential ADC channel in_voltage3-voltage4_raw etc*/ | |
161 | { | |
162 | .type = IIO_VOLTAGE, | |
163 | .differential = 1, | |
164 | .indexed = 1, | |
165 | .channel = 3, | |
166 | .channel2 = 4, | |
fa357a6a JC |
167 | .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), |
168 | .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE), | |
6a63aa0a | 169 | .info_mask_shared_by_dir = BIT(IIO_CHAN_INFO_SAMP_FREQ), |
9ad2e2e1 JC |
170 | .scan_index = diffvoltage3m4, |
171 | .scan_type = { | |
172 | .sign = 's', | |
173 | .realbits = 11, | |
174 | .storagebits = 16, | |
175 | .shift = 0, | |
176 | }, | |
3a84331d JC |
177 | }, |
178 | /* | |
179 | * 'modified' (i.e. axis specified) acceleration channel | |
180 | * in_accel_z_raw | |
181 | */ | |
182 | { | |
183 | .type = IIO_ACCEL, | |
184 | .modified = 1, | |
185 | /* Channel 2 is use for modifiers */ | |
186 | .channel2 = IIO_MOD_X, | |
fa357a6a | 187 | .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | |
3a84331d | 188 | /* |
ff3fc8eb | 189 | * Internal bias and gain correction values. Applied |
3a84331d JC |
190 | * by the hardware or driver prior to userspace |
191 | * seeing the readings. Typically part of hardware | |
192 | * calibration. | |
193 | */ | |
ff3fc8eb | 194 | BIT(IIO_CHAN_INFO_CALIBSCALE) | |
fa357a6a | 195 | BIT(IIO_CHAN_INFO_CALIBBIAS), |
6a63aa0a | 196 | .info_mask_shared_by_dir = BIT(IIO_CHAN_INFO_SAMP_FREQ), |
9ad2e2e1 JC |
197 | .scan_index = accelx, |
198 | .scan_type = { /* Description of storage in buffer */ | |
199 | .sign = 's', /* signed */ | |
25c38aa3 | 200 | .realbits = 16, /* 16 bits */ |
9ad2e2e1 JC |
201 | .storagebits = 16, /* 16 bits used for storage */ |
202 | .shift = 0, /* zero shift */ | |
203 | }, | |
204 | }, | |
205 | /* | |
206 | * Convenience macro for timestamps. 4 is the index in | |
207 | * the buffer. | |
208 | */ | |
209 | IIO_CHAN_SOFT_TIMESTAMP(4), | |
210 | /* DAC channel out_voltage0_raw */ | |
211 | { | |
212 | .type = IIO_VOLTAGE, | |
fa357a6a | 213 | .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), |
9ad2e2e1 JC |
214 | .output = 1, |
215 | .indexed = 1, | |
216 | .channel = 0, | |
3a84331d JC |
217 | }, |
218 | }; | |
219 | ||
220 | /** | |
221 | * iio_dummy_read_raw() - data read function. | |
222 | * @indio_dev: the struct iio_dev associated with this device instance | |
223 | * @chan: the channel whose data is to be read | |
224 | * @val: first element of returned value (typically INT) | |
225 | * @val2: second element of returned value (typically MICRO) | |
fa357a6a JC |
226 | * @mask: what we actually want to read as per the info_mask_* |
227 | * in iio_chan_spec. | |
3a84331d JC |
228 | */ |
229 | static int iio_dummy_read_raw(struct iio_dev *indio_dev, | |
230 | struct iio_chan_spec const *chan, | |
231 | int *val, | |
232 | int *val2, | |
233 | long mask) | |
234 | { | |
235 | struct iio_dummy_state *st = iio_priv(indio_dev); | |
236 | int ret = -EINVAL; | |
237 | ||
238 | mutex_lock(&st->lock); | |
239 | switch (mask) { | |
41fd935b | 240 | case IIO_CHAN_INFO_RAW: /* magic value - channel value read */ |
3a84331d JC |
241 | switch (chan->type) { |
242 | case IIO_VOLTAGE: | |
243 | if (chan->output) { | |
244 | /* Set integer part to cached value */ | |
245 | *val = st->dac_val; | |
246 | ret = IIO_VAL_INT; | |
247 | } else if (chan->differential) { | |
248 | if (chan->channel == 1) | |
249 | *val = st->differential_adc_val[0]; | |
250 | else | |
251 | *val = st->differential_adc_val[1]; | |
252 | ret = IIO_VAL_INT; | |
253 | } else { | |
254 | *val = st->single_ended_adc_val; | |
255 | ret = IIO_VAL_INT; | |
256 | } | |
257 | break; | |
258 | case IIO_ACCEL: | |
259 | *val = st->accel_val; | |
260 | ret = IIO_VAL_INT; | |
261 | break; | |
262 | default: | |
263 | break; | |
264 | } | |
265 | break; | |
c8a9f805 | 266 | case IIO_CHAN_INFO_OFFSET: |
3a84331d JC |
267 | /* only single ended adc -> 7 */ |
268 | *val = 7; | |
269 | ret = IIO_VAL_INT; | |
270 | break; | |
c8a9f805 JC |
271 | case IIO_CHAN_INFO_SCALE: |
272 | switch (chan->differential) { | |
273 | case 0: | |
274 | /* only single ended adc -> 0.001333 */ | |
275 | *val = 0; | |
276 | *val2 = 1333; | |
277 | ret = IIO_VAL_INT_PLUS_MICRO; | |
278 | break; | |
279 | case 1: | |
280 | /* all differential adc channels -> 0.000001344 */ | |
281 | *val = 0; | |
282 | *val2 = 1344; | |
283 | ret = IIO_VAL_INT_PLUS_NANO; | |
284 | } | |
3a84331d | 285 | break; |
c8a9f805 | 286 | case IIO_CHAN_INFO_CALIBBIAS: |
3a84331d JC |
287 | /* only the acceleration axis - read from cache */ |
288 | *val = st->accel_calibbias; | |
289 | ret = IIO_VAL_INT; | |
290 | break; | |
c8a9f805 | 291 | case IIO_CHAN_INFO_CALIBSCALE: |
3a84331d JC |
292 | *val = st->accel_calibscale->val; |
293 | *val2 = st->accel_calibscale->val2; | |
294 | ret = IIO_VAL_INT_PLUS_MICRO; | |
295 | break; | |
6a63aa0a JC |
296 | case IIO_CHAN_INFO_SAMP_FREQ: |
297 | *val = 3; | |
298 | *val2 = 33; | |
299 | ret = IIO_VAL_INT_PLUS_NANO; | |
300 | break; | |
3a84331d JC |
301 | default: |
302 | break; | |
303 | } | |
304 | mutex_unlock(&st->lock); | |
305 | return ret; | |
306 | } | |
307 | ||
308 | /** | |
309 | * iio_dummy_write_raw() - data write function. | |
310 | * @indio_dev: the struct iio_dev associated with this device instance | |
569c4ac2 | 311 | * @chan: the channel whose data is to be written |
25c38aa3 PM |
312 | * @val: first element of value to set (typically INT) |
313 | * @val2: second element of value to set (typically MICRO) | |
fa357a6a JC |
314 | * @mask: what we actually want to write as per the info_mask_* |
315 | * in iio_chan_spec. | |
3a84331d JC |
316 | * |
317 | * Note that all raw writes are assumed IIO_VAL_INT and info mask elements | |
318 | * are assumed to be IIO_INT_PLUS_MICRO unless the callback write_raw_get_fmt | |
319 | * in struct iio_info is provided by the driver. | |
320 | */ | |
321 | static int iio_dummy_write_raw(struct iio_dev *indio_dev, | |
322 | struct iio_chan_spec const *chan, | |
323 | int val, | |
324 | int val2, | |
325 | long mask) | |
326 | { | |
327 | int i; | |
328 | int ret = 0; | |
329 | struct iio_dummy_state *st = iio_priv(indio_dev); | |
330 | ||
331 | switch (mask) { | |
41fd935b | 332 | case IIO_CHAN_INFO_RAW: |
3a84331d JC |
333 | if (chan->output == 0) |
334 | return -EINVAL; | |
335 | ||
336 | /* Locking not required as writing single value */ | |
337 | mutex_lock(&st->lock); | |
338 | st->dac_val = val; | |
339 | mutex_unlock(&st->lock); | |
340 | return 0; | |
ff3fc8eb | 341 | case IIO_CHAN_INFO_CALIBSCALE: |
3a84331d JC |
342 | mutex_lock(&st->lock); |
343 | /* Compare against table - hard matching here */ | |
344 | for (i = 0; i < ARRAY_SIZE(dummy_scales); i++) | |
345 | if (val == dummy_scales[i].val && | |
346 | val2 == dummy_scales[i].val2) | |
347 | break; | |
348 | if (i == ARRAY_SIZE(dummy_scales)) | |
349 | ret = -EINVAL; | |
350 | else | |
351 | st->accel_calibscale = &dummy_scales[i]; | |
352 | mutex_unlock(&st->lock); | |
353 | return ret; | |
ff3fc8eb JF |
354 | case IIO_CHAN_INFO_CALIBBIAS: |
355 | mutex_lock(&st->lock); | |
356 | st->accel_calibbias = val; | |
357 | mutex_unlock(&st->lock); | |
358 | return 0; | |
359 | ||
3a84331d JC |
360 | default: |
361 | return -EINVAL; | |
362 | } | |
363 | } | |
364 | ||
365 | /* | |
366 | * Device type specific information. | |
367 | */ | |
368 | static const struct iio_info iio_dummy_info = { | |
369 | .driver_module = THIS_MODULE, | |
370 | .read_raw = &iio_dummy_read_raw, | |
371 | .write_raw = &iio_dummy_write_raw, | |
e6477000 | 372 | #ifdef CONFIG_IIO_SIMPLE_DUMMY_EVENTS |
cb955852 LPC |
373 | .read_event_config = &iio_simple_dummy_read_event_config, |
374 | .write_event_config = &iio_simple_dummy_write_event_config, | |
375 | .read_event_value = &iio_simple_dummy_read_event_value, | |
376 | .write_event_value = &iio_simple_dummy_write_event_value, | |
e6477000 | 377 | #endif /* CONFIG_IIO_SIMPLE_DUMMY_EVENTS */ |
3a84331d JC |
378 | }; |
379 | ||
380 | /** | |
381 | * iio_dummy_init_device() - device instance specific init | |
382 | * @indio_dev: the iio device structure | |
383 | * | |
384 | * Most drivers have one of these to set up default values, | |
385 | * reset the device to known state etc. | |
386 | */ | |
387 | static int iio_dummy_init_device(struct iio_dev *indio_dev) | |
388 | { | |
389 | struct iio_dummy_state *st = iio_priv(indio_dev); | |
390 | ||
391 | st->dac_val = 0; | |
392 | st->single_ended_adc_val = 73; | |
393 | st->differential_adc_val[0] = 33; | |
394 | st->differential_adc_val[1] = -34; | |
395 | st->accel_val = 34; | |
396 | st->accel_calibbias = -7; | |
397 | st->accel_calibscale = &dummy_scales[0]; | |
398 | ||
399 | return 0; | |
400 | } | |
401 | ||
402 | /** | |
403 | * iio_dummy_probe() - device instance probe | |
404 | * @index: an id number for this instance. | |
405 | * | |
406 | * Arguments are bus type specific. | |
407 | * I2C: iio_dummy_probe(struct i2c_client *client, | |
408 | * const struct i2c_device_id *id) | |
409 | * SPI: iio_dummy_probe(struct spi_device *spi) | |
410 | */ | |
4ae1c61f | 411 | static int iio_dummy_probe(int index) |
3a84331d JC |
412 | { |
413 | int ret; | |
414 | struct iio_dev *indio_dev; | |
415 | struct iio_dummy_state *st; | |
416 | ||
417 | /* | |
418 | * Allocate an IIO device. | |
419 | * | |
420 | * This structure contains all generic state | |
421 | * information about the device instance. | |
422 | * It also has a region (accessed by iio_priv() | |
423 | * for chip specific state information. | |
424 | */ | |
7cbb7537 | 425 | indio_dev = iio_device_alloc(sizeof(*st)); |
3a84331d JC |
426 | if (indio_dev == NULL) { |
427 | ret = -ENOMEM; | |
428 | goto error_ret; | |
429 | } | |
430 | ||
431 | st = iio_priv(indio_dev); | |
432 | mutex_init(&st->lock); | |
433 | ||
434 | iio_dummy_init_device(indio_dev); | |
435 | /* | |
436 | * With hardware: Set the parent device. | |
437 | * indio_dev->dev.parent = &spi->dev; | |
438 | * indio_dev->dev.parent = &client->dev; | |
439 | */ | |
440 | ||
441 | /* | |
442 | * Make the iio_dev struct available to remove function. | |
443 | * Bus equivalents | |
444 | * i2c_set_clientdata(client, indio_dev); | |
445 | * spi_set_drvdata(spi, indio_dev); | |
446 | */ | |
447 | iio_dummy_devs[index] = indio_dev; | |
448 | ||
449 | ||
450 | /* | |
451 | * Set the device name. | |
452 | * | |
453 | * This is typically a part number and obtained from the module | |
454 | * id table. | |
455 | * e.g. for i2c and spi: | |
456 | * indio_dev->name = id->name; | |
457 | * indio_dev->name = spi_get_device_id(spi)->name; | |
458 | */ | |
459 | indio_dev->name = iio_dummy_part_number; | |
460 | ||
461 | /* Provide description of available channels */ | |
462 | indio_dev->channels = iio_dummy_channels; | |
463 | indio_dev->num_channels = ARRAY_SIZE(iio_dummy_channels); | |
464 | ||
465 | /* | |
466 | * Provide device type specific interface functions and | |
467 | * constant data. | |
468 | */ | |
469 | indio_dev->info = &iio_dummy_info; | |
470 | ||
471 | /* Specify that device provides sysfs type interfaces */ | |
472 | indio_dev->modes = INDIO_DIRECT_MODE; | |
473 | ||
e6477000 | 474 | ret = iio_simple_dummy_events_register(indio_dev); |
3a84331d JC |
475 | if (ret < 0) |
476 | goto error_free_device; | |
9ad2e2e1 | 477 | |
9ad2e2e1 | 478 | /* |
3fff2274 LPC |
479 | * Configure buffered capture support and register the channels with the |
480 | * buffer, but avoid the output channel being registered by reducing the | |
481 | * number of channels by 1. | |
9ad2e2e1 | 482 | */ |
d7c0886e EA |
483 | ret = iio_simple_dummy_configure_buffer(indio_dev, |
484 | iio_dummy_channels, 5); | |
9ad2e2e1 | 485 | if (ret < 0) |
3fff2274 | 486 | goto error_unregister_events; |
9ad2e2e1 JC |
487 | |
488 | ret = iio_device_register(indio_dev); | |
489 | if (ret < 0) | |
3fff2274 | 490 | goto error_unconfigure_buffer; |
9ad2e2e1 | 491 | |
3a84331d | 492 | return 0; |
9ad2e2e1 JC |
493 | error_unconfigure_buffer: |
494 | iio_simple_dummy_unconfigure_buffer(indio_dev); | |
e6477000 JC |
495 | error_unregister_events: |
496 | iio_simple_dummy_events_unregister(indio_dev); | |
3a84331d | 497 | error_free_device: |
7cbb7537 | 498 | iio_device_free(indio_dev); |
3a84331d JC |
499 | error_ret: |
500 | return ret; | |
501 | } | |
502 | ||
503 | /** | |
504 | * iio_dummy_remove() - device instance removal function | |
505 | * @index: device index. | |
506 | * | |
507 | * Parameters follow those of iio_dummy_probe for buses. | |
508 | */ | |
509 | static int iio_dummy_remove(int index) | |
510 | { | |
e6477000 | 511 | int ret; |
3a84331d JC |
512 | /* |
513 | * Get a pointer to the device instance iio_dev structure | |
514 | * from the bus subsystem. E.g. | |
515 | * struct iio_dev *indio_dev = i2c_get_clientdata(client); | |
516 | * struct iio_dev *indio_dev = spi_get_drvdata(spi); | |
517 | */ | |
518 | struct iio_dev *indio_dev = iio_dummy_devs[index]; | |
519 | ||
e6477000 | 520 | |
3a84331d JC |
521 | /* Unregister the device */ |
522 | iio_device_unregister(indio_dev); | |
523 | ||
524 | /* Device specific code to power down etc */ | |
525 | ||
9ad2e2e1 | 526 | /* Buffered capture related cleanup */ |
9ad2e2e1 | 527 | iio_simple_dummy_unconfigure_buffer(indio_dev); |
e6477000 JC |
528 | |
529 | ret = iio_simple_dummy_events_unregister(indio_dev); | |
530 | if (ret) | |
531 | goto error_ret; | |
532 | ||
3a84331d | 533 | /* Free all structures */ |
7cbb7537 | 534 | iio_device_free(indio_dev); |
3a84331d | 535 | |
e6477000 JC |
536 | error_ret: |
537 | return ret; | |
3a84331d JC |
538 | } |
539 | ||
540 | /** | |
541 | * iio_dummy_init() - device driver registration | |
542 | * | |
543 | * Varies depending on bus type of the device. As there is no device | |
544 | * here, call probe directly. For information on device registration | |
545 | * i2c: | |
546 | * Documentation/i2c/writing-clients | |
547 | * spi: | |
548 | * Documentation/spi/spi-summary | |
549 | */ | |
550 | static __init int iio_dummy_init(void) | |
551 | { | |
552 | int i, ret; | |
553 | if (instances > 10) { | |
554 | instances = 1; | |
555 | return -EINVAL; | |
556 | } | |
3fff2274 | 557 | |
3a84331d | 558 | /* Fake a bus */ |
d83fb184 TM |
559 | iio_dummy_devs = kcalloc(instances, sizeof(*iio_dummy_devs), |
560 | GFP_KERNEL); | |
3a84331d JC |
561 | /* Here we have no actual device so call probe */ |
562 | for (i = 0; i < instances; i++) { | |
563 | ret = iio_dummy_probe(i); | |
564 | if (ret < 0) | |
565 | return ret; | |
566 | } | |
567 | return 0; | |
568 | } | |
569 | module_init(iio_dummy_init); | |
570 | ||
571 | /** | |
572 | * iio_dummy_exit() - device driver removal | |
573 | * | |
574 | * Varies depending on bus type of the device. | |
575 | * As there is no device here, call remove directly. | |
576 | */ | |
577 | static __exit void iio_dummy_exit(void) | |
578 | { | |
579 | int i; | |
580 | for (i = 0; i < instances; i++) | |
581 | iio_dummy_remove(i); | |
582 | kfree(iio_dummy_devs); | |
583 | } | |
584 | module_exit(iio_dummy_exit); | |
585 | ||
0f8c9620 | 586 | MODULE_AUTHOR("Jonathan Cameron <jic23@kernel.org>"); |
3a84331d JC |
587 | MODULE_DESCRIPTION("IIO dummy driver"); |
588 | MODULE_LICENSE("GPL v2"); |