Commit | Line | Data |
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3cf840f6 DS |
1 | /* |
2 | comedi/drivers/comedi_bond.c | |
3 | A Comedi driver to 'bond' or merge multiple drivers and devices as one. | |
4 | ||
5 | COMEDI - Linux Control and Measurement Device Interface | |
6 | Copyright (C) 2000 David A. Schleef <ds@schleef.org> | |
7 | Copyright (C) 2005 Calin A. Culianu <calin@ajvar.org> | |
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 as published by | |
11 | the Free Software Foundation; either version 2 of the License, or | |
12 | (at your option) any later version. | |
13 | ||
14 | This program is distributed in the hope that it will be useful, | |
15 | but WITHOUT ANY WARRANTY; without even the implied warranty of | |
16 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
17 | GNU General Public License for more details. | |
18 | ||
19 | You should have received a copy of the GNU General Public License | |
20 | along with this program; if not, write to the Free Software | |
21 | Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. | |
22 | ||
23 | */ | |
24 | /* | |
25 | Driver: comedi_bond | |
e7f2aa34 GKH |
26 | Description: A driver to 'bond' (merge) multiple subdevices from multiple |
27 | devices together as one. | |
3cf840f6 DS |
28 | Devices: |
29 | Author: ds | |
30 | Updated: Mon, 10 Oct 00:18:25 -0500 | |
31 | Status: works | |
32 | ||
33 | This driver allows you to 'bond' (merge) multiple comedi subdevices | |
34 | (coming from possibly difference boards and/or drivers) together. For | |
35 | example, if you had a board with 2 different DIO subdevices, and | |
36 | another with 1 DIO subdevice, you could 'bond' them with this driver | |
37 | so that they look like one big fat DIO subdevice. This makes writing | |
38 | applications slightly easier as you don't have to worry about managing | |
39 | different subdevices in the application -- you just worry about | |
40 | indexing one linear array of channel id's. | |
41 | ||
42 | Right now only DIO subdevices are supported as that's the personal itch | |
43 | I am scratching with this driver. If you want to add support for AI and AO | |
44 | subdevs, go right on ahead and do so! | |
45 | ||
46 | Commands aren't supported -- although it would be cool if they were. | |
47 | ||
48 | Configuration Options: | |
49 | List of comedi-minors to bond. All subdevices of the same type | |
50 | within each minor will be concatenated together in the order given here. | |
51 | */ | |
52 | ||
3b6b25b5 GKH |
53 | #include <linux/string.h> |
54 | #include <linux/slab.h> | |
e2a0eab0 | 55 | #include "../comedi.h" |
3cf840f6 DS |
56 | #include "../comedilib.h" |
57 | #include "../comedidev.h" | |
3cf840f6 DS |
58 | |
59 | /* The maxiumum number of channels per subdevice. */ | |
60 | #define MAX_CHANS 256 | |
61 | ||
62 | #define MODULE_NAME "comedi_bond" | |
3cf840f6 DS |
63 | #ifndef STR |
64 | # define STR1(x) #x | |
65 | # define STR(x) STR1(x) | |
66 | #endif | |
67 | ||
246c5418 | 68 | static int debug; |
3cf840f6 | 69 | module_param(debug, int, 0644); |
e7f2aa34 GKH |
70 | MODULE_PARM_DESC(debug, "If true, print extra cryptic debugging output useful" |
71 | "only to developers."); | |
3cf840f6 DS |
72 | |
73 | #define LOG_MSG(x...) printk(KERN_INFO MODULE_NAME": "x) | |
e7f2aa34 GKH |
74 | #define DEBUG(x...) \ |
75 | do { \ | |
76 | if (debug) \ | |
77 | printk(KERN_DEBUG MODULE_NAME": DEBUG: "x); \ | |
78 | } while (0) | |
3cf840f6 DS |
79 | #define WARNING(x...) printk(KERN_WARNING MODULE_NAME ": WARNING: "x) |
80 | #define ERROR(x...) printk(KERN_ERR MODULE_NAME ": INTERNAL ERROR: "x) | |
3cf840f6 DS |
81 | |
82 | /* | |
83 | * Board descriptions for two imaginary boards. Describing the | |
84 | * boards in this way is optional, and completely driver-dependent. | |
85 | * Some drivers use arrays such as this, other do not. | |
86 | */ | |
87 | struct BondingBoard { | |
88 | const char *name; | |
89 | }; | |
3cf840f6 | 90 | |
3cf840f6 DS |
91 | /* |
92 | * Useful for shorthand access to the particular board structure | |
93 | */ | |
ff534766 | 94 | #define thisboard ((const struct BondingBoard *)dev->board_ptr) |
3cf840f6 DS |
95 | |
96 | struct BondedDevice { | |
472dfe77 | 97 | struct comedi_device *dev; |
3cf840f6 DS |
98 | unsigned minor; |
99 | unsigned subdev; | |
100 | unsigned subdev_type; | |
101 | unsigned nchans; | |
e7f2aa34 GKH |
102 | unsigned chanid_offset; /* The offset into our unified linear |
103 | channel-id's of chanid 0 on this | |
104 | subdevice. */ | |
3cf840f6 | 105 | }; |
3cf840f6 DS |
106 | |
107 | /* this structure is for data unique to this hardware driver. If | |
108 | several hardware drivers keep similar information in this structure, | |
71b5f4f1 | 109 | feel free to suggest moving the variable to the struct comedi_device struct. */ |
3cf840f6 DS |
110 | struct Private { |
111 | # define MAX_BOARD_NAME 256 | |
112 | char name[MAX_BOARD_NAME]; | |
113 | struct BondedDevice **devs; | |
114 | unsigned ndevs; | |
115 | struct BondedDevice *chanIdDevMap[MAX_CHANS]; | |
116 | unsigned nchans; | |
117 | }; | |
3cf840f6 DS |
118 | |
119 | /* | |
120 | * most drivers define the following macro to make it easy to | |
121 | * access the private structure. | |
122 | */ | |
ff534766 | 123 | #define devpriv ((struct Private *)dev->private) |
3cf840f6 | 124 | |
3cf840f6 DS |
125 | /* DIO devices are slightly special. Although it is possible to |
126 | * implement the insn_read/insn_write interface, it is much more | |
127 | * useful to applications if you implement the insn_bits interface. | |
128 | * This allows packed reading/writing of the DIO channels. The | |
129 | * comedi core can convert between insn_bits and insn_read/write */ | |
0a85b6f0 MT |
130 | static int bonding_dio_insn_bits(struct comedi_device *dev, |
131 | struct comedi_subdevice *s, | |
90035c08 | 132 | struct comedi_insn *insn, unsigned int *data) |
3cf840f6 | 133 | { |
790c5541 | 134 | #define LSAMPL_BITS (sizeof(unsigned int)*8) |
3cf840f6 DS |
135 | unsigned nchans = LSAMPL_BITS, num_done = 0, i; |
136 | if (insn->n != 2) | |
137 | return -EINVAL; | |
138 | ||
139 | if (devpriv->nchans < nchans) | |
140 | nchans = devpriv->nchans; | |
141 | ||
142 | /* The insn data is a mask in data[0] and the new data | |
143 | * in data[1], each channel cooresponding to a bit. */ | |
144 | for (i = 0; num_done < nchans && i < devpriv->ndevs; ++i) { | |
ff534766 | 145 | struct BondedDevice *bdev = devpriv->devs[i]; |
3cf840f6 DS |
146 | /* Grab the channel mask and data of only the bits corresponding |
147 | to this subdevice.. need to shift them to zero position of | |
148 | course. */ | |
e7f2aa34 | 149 | /* Bits corresponding to this subdev. */ |
790c5541 BP |
150 | unsigned int subdevMask = ((1 << bdev->nchans) - 1); |
151 | unsigned int writeMask, dataBits; | |
3cf840f6 DS |
152 | |
153 | /* Argh, we have >= LSAMPL_BITS chans.. take all bits */ | |
154 | if (bdev->nchans >= LSAMPL_BITS) | |
0a85b6f0 | 155 | subdevMask = (unsigned int)(-1); |
3cf840f6 DS |
156 | |
157 | writeMask = (data[0] >> num_done) & subdevMask; | |
158 | dataBits = (data[1] >> num_done) & subdevMask; | |
159 | ||
160 | /* Read/Write the new digital lines */ | |
161 | if (comedi_dio_bitfield(bdev->dev, bdev->subdev, writeMask, | |
0a85b6f0 | 162 | &dataBits) != 2) |
3cf840f6 DS |
163 | return -EINVAL; |
164 | ||
165 | /* Make room for the new bits in data[1], the return value */ | |
166 | data[1] &= ~(subdevMask << num_done); | |
167 | /* Put the bits in the return value */ | |
168 | data[1] |= (dataBits & subdevMask) << num_done; | |
169 | /* Save the new bits to the saved state.. */ | |
170 | s->state = data[1]; | |
171 | ||
172 | num_done += bdev->nchans; | |
173 | } | |
174 | ||
175 | return insn->n; | |
176 | } | |
177 | ||
0a85b6f0 MT |
178 | static int bonding_dio_insn_config(struct comedi_device *dev, |
179 | struct comedi_subdevice *s, | |
90035c08 | 180 | struct comedi_insn *insn, unsigned int *data) |
3cf840f6 DS |
181 | { |
182 | int chan = CR_CHAN(insn->chanspec), ret, io_bits = s->io_bits; | |
183 | unsigned int io; | |
ff534766 | 184 | struct BondedDevice *bdev; |
3cf840f6 DS |
185 | |
186 | if (chan < 0 || chan >= devpriv->nchans) | |
187 | return -EINVAL; | |
188 | bdev = devpriv->chanIdDevMap[chan]; | |
189 | ||
190 | /* The input or output configuration of each digital line is | |
191 | * configured by a special insn_config instruction. chanspec | |
192 | * contains the channel to be changed, and data[0] contains the | |
193 | * value COMEDI_INPUT or COMEDI_OUTPUT. */ | |
194 | switch (data[0]) { | |
195 | case INSN_CONFIG_DIO_OUTPUT: | |
196 | io = COMEDI_OUTPUT; /* is this really necessary? */ | |
197 | io_bits |= 1 << chan; | |
198 | break; | |
199 | case INSN_CONFIG_DIO_INPUT: | |
200 | io = COMEDI_INPUT; /* is this really necessary? */ | |
201 | io_bits &= ~(1 << chan); | |
202 | break; | |
203 | case INSN_CONFIG_DIO_QUERY: | |
204 | data[1] = | |
0a85b6f0 | 205 | (io_bits & (1 << chan)) ? COMEDI_OUTPUT : COMEDI_INPUT; |
3cf840f6 DS |
206 | return insn->n; |
207 | break; | |
208 | default: | |
209 | return -EINVAL; | |
210 | break; | |
211 | } | |
e7f2aa34 GKH |
212 | /* 'real' channel id for this subdev.. */ |
213 | chan -= bdev->chanid_offset; | |
3cf840f6 DS |
214 | ret = comedi_dio_config(bdev->dev, bdev->subdev, chan, io); |
215 | if (ret != 1) | |
216 | return -EINVAL; | |
217 | /* Finally, save the new io_bits values since we didn't get | |
218 | an error above. */ | |
219 | s->io_bits = io_bits; | |
220 | return insn->n; | |
221 | } | |
222 | ||
223 | static void *Realloc(const void *oldmem, size_t newlen, size_t oldlen) | |
224 | { | |
3cf840f6 | 225 | void *newmem = kmalloc(newlen, GFP_KERNEL); |
e7f2aa34 | 226 | |
3cf840f6 | 227 | if (newmem && oldmem) |
e7f2aa34 GKH |
228 | memcpy(newmem, oldmem, min(oldlen, newlen)); |
229 | kfree(oldmem); | |
3cf840f6 DS |
230 | return newmem; |
231 | } | |
232 | ||
0707bb04 | 233 | static int doDevConfig(struct comedi_device *dev, struct comedi_devconfig *it) |
3cf840f6 DS |
234 | { |
235 | int i; | |
472dfe77 | 236 | struct comedi_device *devs_opened[COMEDI_NUM_BOARD_MINORS]; |
3cf840f6 DS |
237 | |
238 | memset(devs_opened, 0, sizeof(devs_opened)); | |
859171ca | 239 | devpriv->name[0] = 0; |
3cf840f6 DS |
240 | /* Loop through all comedi devices specified on the command-line, |
241 | building our device list */ | |
242 | for (i = 0; i < COMEDI_NDEVCONFOPTS && (!i || it->options[i]); ++i) { | |
243 | char file[] = "/dev/comediXXXXXX"; | |
244 | int minor = it->options[i]; | |
472dfe77 | 245 | struct comedi_device *d; |
3cf840f6 | 246 | int sdev = -1, nchans, tmp; |
246c5418 | 247 | struct BondedDevice *bdev = NULL; |
3cf840f6 | 248 | |
5d3aed74 | 249 | if (minor < 0 || minor >= COMEDI_NUM_BOARD_MINORS) { |
3cf840f6 DS |
250 | ERROR("Minor %d is invalid!\n", minor); |
251 | return 0; | |
252 | } | |
253 | if (minor == dev->minor) { | |
254 | ERROR("Cannot bond this driver to itself!\n"); | |
255 | return 0; | |
256 | } | |
257 | if (devs_opened[minor]) { | |
258 | ERROR("Minor %d specified more than once!\n", minor); | |
259 | return 0; | |
260 | } | |
261 | ||
262 | snprintf(file, sizeof(file), "/dev/comedi%u", minor); | |
263 | file[sizeof(file) - 1] = 0; | |
264 | ||
265 | d = devs_opened[minor] = comedi_open(file); | |
266 | ||
267 | if (!d) { | |
268 | ERROR("Minor %u could not be opened\n", minor); | |
269 | return 0; | |
270 | } | |
271 | ||
272 | /* Do DIO, as that's all we support now.. */ | |
273 | while ((sdev = comedi_find_subdevice_by_type(d, COMEDI_SUBD_DIO, | |
0a85b6f0 | 274 | sdev + 1)) > -1) { |
e7f2aa34 GKH |
275 | nchans = comedi_get_n_channels(d, sdev); |
276 | if (nchans <= 0) { | |
277 | ERROR("comedi_get_n_channels() returned %d " | |
278 | "on minor %u subdev %d!\n", | |
279 | nchans, minor, sdev); | |
3cf840f6 DS |
280 | return 0; |
281 | } | |
282 | bdev = kmalloc(sizeof(*bdev), GFP_KERNEL); | |
283 | if (!bdev) { | |
284 | ERROR("Out of memory.\n"); | |
285 | return 0; | |
286 | } | |
287 | bdev->dev = d; | |
288 | bdev->minor = minor; | |
289 | bdev->subdev = sdev; | |
290 | bdev->subdev_type = COMEDI_SUBD_DIO; | |
291 | bdev->nchans = nchans; | |
292 | bdev->chanid_offset = devpriv->nchans; | |
293 | ||
294 | /* map channel id's to BondedDevice * pointer.. */ | |
295 | while (nchans--) | |
296 | devpriv->chanIdDevMap[devpriv->nchans++] = bdev; | |
297 | ||
e7f2aa34 GKH |
298 | /* Now put bdev pointer at end of devpriv->devs array |
299 | * list.. */ | |
3cf840f6 DS |
300 | |
301 | /* ergh.. ugly.. we need to realloc :( */ | |
302 | tmp = devpriv->ndevs * sizeof(bdev); | |
303 | devpriv->devs = | |
0a85b6f0 MT |
304 | Realloc(devpriv->devs, |
305 | ++devpriv->ndevs * sizeof(bdev), tmp); | |
3cf840f6 | 306 | if (!devpriv->devs) { |
e7f2aa34 GKH |
307 | ERROR("Could not allocate memory. " |
308 | "Out of memory?"); | |
3cf840f6 DS |
309 | return 0; |
310 | } | |
311 | ||
312 | devpriv->devs[devpriv->ndevs - 1] = bdev; | |
313 | { | |
314 | /** Append dev:subdev to devpriv->name */ | |
315 | char buf[20]; | |
316 | int left = | |
0a85b6f0 | 317 | MAX_BOARD_NAME - strlen(devpriv->name) - 1; |
3cf840f6 | 318 | snprintf(buf, sizeof(buf), "%d:%d ", dev->minor, |
0a85b6f0 | 319 | bdev->subdev); |
3cf840f6 DS |
320 | buf[sizeof(buf) - 1] = 0; |
321 | strncat(devpriv->name, buf, left); | |
322 | } | |
323 | ||
324 | } | |
325 | } | |
326 | ||
327 | if (!devpriv->nchans) { | |
328 | ERROR("No channels found!\n"); | |
329 | return 0; | |
330 | } | |
331 | ||
332 | return 1; | |
333 | } | |
334 | ||
ecdc3e0d HS |
335 | static int bonding_attach(struct comedi_device *dev, |
336 | struct comedi_devconfig *it) | |
3cf840f6 | 337 | { |
ecdc3e0d HS |
338 | struct comedi_subdevice *s; |
339 | ||
340 | LOG_MSG("comedi%d\n", dev->minor); | |
341 | ||
342 | /* | |
343 | * Allocate the private structure area. alloc_private() is a | |
344 | * convenient macro defined in comedidev.h. | |
345 | */ | |
346 | if (alloc_private(dev, sizeof(struct Private)) < 0) | |
347 | return -ENOMEM; | |
348 | ||
349 | /* | |
350 | * Setup our bonding from config params.. sets up our Private struct.. | |
351 | */ | |
352 | if (!doDevConfig(dev, it)) | |
353 | return -EINVAL; | |
354 | ||
355 | /* | |
356 | * Initialize dev->board_name. Note that we can use the "thisboard" | |
357 | * macro now, since we just initialized it in the last line. | |
358 | */ | |
359 | dev->board_name = devpriv->name; | |
360 | ||
2f0b9d08 | 361 | if (comedi_alloc_subdevices(dev, 1) < 0) |
ecdc3e0d HS |
362 | return -ENOMEM; |
363 | ||
364 | s = dev->subdevices + 0; | |
365 | s->type = COMEDI_SUBD_DIO; | |
366 | s->subdev_flags = SDF_READABLE | SDF_WRITABLE; | |
367 | s->n_chan = devpriv->nchans; | |
368 | s->maxdata = 1; | |
369 | s->range_table = &range_digital; | |
370 | s->insn_bits = bonding_dio_insn_bits; | |
371 | s->insn_config = bonding_dio_insn_config; | |
372 | ||
373 | LOG_MSG("attached with %u DIO channels coming from %u different " | |
374 | "subdevices all bonded together. " | |
375 | "John Lennon would be proud!\n", | |
376 | devpriv->nchans, devpriv->ndevs); | |
377 | ||
378 | return 1; | |
3cf840f6 DS |
379 | } |
380 | ||
484ecc95 | 381 | static void bonding_detach(struct comedi_device *dev) |
3cf840f6 | 382 | { |
484ecc95 HS |
383 | unsigned long devs_closed = 0; |
384 | ||
385 | if (devpriv) { | |
386 | while (devpriv->ndevs-- && devpriv->devs) { | |
387 | struct BondedDevice *bdev; | |
388 | ||
389 | bdev = devpriv->devs[devpriv->ndevs]; | |
390 | if (!bdev) | |
391 | continue; | |
392 | if (!(devs_closed & (0x1 << bdev->minor))) { | |
393 | comedi_close(bdev->dev); | |
394 | devs_closed |= (0x1 << bdev->minor); | |
395 | } | |
396 | kfree(bdev); | |
397 | } | |
398 | kfree(devpriv->devs); | |
399 | devpriv->devs = NULL; | |
400 | kfree(devpriv); | |
401 | dev->private = NULL; | |
402 | } | |
3cf840f6 DS |
403 | } |
404 | ||
ecdc3e0d HS |
405 | static const struct BondingBoard bondingBoards[] = { |
406 | { | |
407 | .name = "comedi_bond", | |
408 | }, | |
409 | }; | |
410 | ||
411 | static struct comedi_driver bonding_driver = { | |
412 | .driver_name = "comedi_bond", | |
413 | .module = THIS_MODULE, | |
414 | .attach = bonding_attach, | |
415 | .detach = bonding_detach, | |
416 | .board_name = &bondingBoards[0].name, | |
417 | .offset = sizeof(struct BondingBoard), | |
418 | .num_names = ARRAY_SIZE(bondingBoards), | |
419 | }; | |
420 | module_comedi_driver(bonding_driver); | |
421 | ||
422 | MODULE_AUTHOR("Calin A. Culianu"); | |
423 | MODULE_DESCRIPTION(MODULE_NAME "A driver for COMEDI to bond multiple COMEDI " | |
424 | "devices together as one. In the words of John Lennon: " | |
425 | "'And the world will live as one...'"); | |
426 | MODULE_LICENSE("GPL"); |