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 | ||
3cf840f6 | 62 | struct BondedDevice { |
472dfe77 | 63 | struct comedi_device *dev; |
3cf840f6 DS |
64 | unsigned minor; |
65 | unsigned subdev; | |
66 | unsigned subdev_type; | |
67 | unsigned nchans; | |
e7f2aa34 GKH |
68 | unsigned chanid_offset; /* The offset into our unified linear |
69 | channel-id's of chanid 0 on this | |
70 | subdevice. */ | |
3cf840f6 | 71 | }; |
3cf840f6 DS |
72 | |
73 | /* this structure is for data unique to this hardware driver. If | |
74 | several hardware drivers keep similar information in this structure, | |
71b5f4f1 | 75 | feel free to suggest moving the variable to the struct comedi_device struct. */ |
a62a1764 | 76 | struct comedi_bond_private { |
3cf840f6 DS |
77 | # define MAX_BOARD_NAME 256 |
78 | char name[MAX_BOARD_NAME]; | |
79 | struct BondedDevice **devs; | |
80 | unsigned ndevs; | |
81 | struct BondedDevice *chanIdDevMap[MAX_CHANS]; | |
82 | unsigned nchans; | |
83 | }; | |
3cf840f6 | 84 | |
3cf840f6 DS |
85 | /* DIO devices are slightly special. Although it is possible to |
86 | * implement the insn_read/insn_write interface, it is much more | |
87 | * useful to applications if you implement the insn_bits interface. | |
88 | * This allows packed reading/writing of the DIO channels. The | |
89 | * comedi core can convert between insn_bits and insn_read/write */ | |
0a85b6f0 MT |
90 | static int bonding_dio_insn_bits(struct comedi_device *dev, |
91 | struct comedi_subdevice *s, | |
90035c08 | 92 | struct comedi_insn *insn, unsigned int *data) |
3cf840f6 | 93 | { |
a62a1764 | 94 | struct comedi_bond_private *devpriv = dev->private; |
790c5541 | 95 | #define LSAMPL_BITS (sizeof(unsigned int)*8) |
3cf840f6 | 96 | unsigned nchans = LSAMPL_BITS, num_done = 0, i; |
3cf840f6 DS |
97 | |
98 | if (devpriv->nchans < nchans) | |
99 | nchans = devpriv->nchans; | |
100 | ||
101 | /* The insn data is a mask in data[0] and the new data | |
102 | * in data[1], each channel cooresponding to a bit. */ | |
103 | for (i = 0; num_done < nchans && i < devpriv->ndevs; ++i) { | |
ff534766 | 104 | struct BondedDevice *bdev = devpriv->devs[i]; |
3cf840f6 DS |
105 | /* Grab the channel mask and data of only the bits corresponding |
106 | to this subdevice.. need to shift them to zero position of | |
107 | course. */ | |
e7f2aa34 | 108 | /* Bits corresponding to this subdev. */ |
790c5541 BP |
109 | unsigned int subdevMask = ((1 << bdev->nchans) - 1); |
110 | unsigned int writeMask, dataBits; | |
3cf840f6 DS |
111 | |
112 | /* Argh, we have >= LSAMPL_BITS chans.. take all bits */ | |
113 | if (bdev->nchans >= LSAMPL_BITS) | |
0a85b6f0 | 114 | subdevMask = (unsigned int)(-1); |
3cf840f6 DS |
115 | |
116 | writeMask = (data[0] >> num_done) & subdevMask; | |
117 | dataBits = (data[1] >> num_done) & subdevMask; | |
118 | ||
119 | /* Read/Write the new digital lines */ | |
120 | if (comedi_dio_bitfield(bdev->dev, bdev->subdev, writeMask, | |
0a85b6f0 | 121 | &dataBits) != 2) |
3cf840f6 DS |
122 | return -EINVAL; |
123 | ||
124 | /* Make room for the new bits in data[1], the return value */ | |
125 | data[1] &= ~(subdevMask << num_done); | |
126 | /* Put the bits in the return value */ | |
127 | data[1] |= (dataBits & subdevMask) << num_done; | |
128 | /* Save the new bits to the saved state.. */ | |
129 | s->state = data[1]; | |
130 | ||
131 | num_done += bdev->nchans; | |
132 | } | |
133 | ||
134 | return insn->n; | |
135 | } | |
136 | ||
0a85b6f0 MT |
137 | static int bonding_dio_insn_config(struct comedi_device *dev, |
138 | struct comedi_subdevice *s, | |
90035c08 | 139 | struct comedi_insn *insn, unsigned int *data) |
3cf840f6 | 140 | { |
a62a1764 | 141 | struct comedi_bond_private *devpriv = dev->private; |
3cf840f6 DS |
142 | int chan = CR_CHAN(insn->chanspec), ret, io_bits = s->io_bits; |
143 | unsigned int io; | |
ff534766 | 144 | struct BondedDevice *bdev; |
3cf840f6 DS |
145 | |
146 | if (chan < 0 || chan >= devpriv->nchans) | |
147 | return -EINVAL; | |
148 | bdev = devpriv->chanIdDevMap[chan]; | |
149 | ||
150 | /* The input or output configuration of each digital line is | |
151 | * configured by a special insn_config instruction. chanspec | |
152 | * contains the channel to be changed, and data[0] contains the | |
153 | * value COMEDI_INPUT or COMEDI_OUTPUT. */ | |
154 | switch (data[0]) { | |
155 | case INSN_CONFIG_DIO_OUTPUT: | |
156 | io = COMEDI_OUTPUT; /* is this really necessary? */ | |
157 | io_bits |= 1 << chan; | |
158 | break; | |
159 | case INSN_CONFIG_DIO_INPUT: | |
160 | io = COMEDI_INPUT; /* is this really necessary? */ | |
161 | io_bits &= ~(1 << chan); | |
162 | break; | |
163 | case INSN_CONFIG_DIO_QUERY: | |
164 | data[1] = | |
0a85b6f0 | 165 | (io_bits & (1 << chan)) ? COMEDI_OUTPUT : COMEDI_INPUT; |
3cf840f6 DS |
166 | return insn->n; |
167 | break; | |
168 | default: | |
169 | return -EINVAL; | |
170 | break; | |
171 | } | |
e7f2aa34 GKH |
172 | /* 'real' channel id for this subdev.. */ |
173 | chan -= bdev->chanid_offset; | |
3cf840f6 DS |
174 | ret = comedi_dio_config(bdev->dev, bdev->subdev, chan, io); |
175 | if (ret != 1) | |
176 | return -EINVAL; | |
177 | /* Finally, save the new io_bits values since we didn't get | |
178 | an error above. */ | |
179 | s->io_bits = io_bits; | |
180 | return insn->n; | |
181 | } | |
182 | ||
183 | static void *Realloc(const void *oldmem, size_t newlen, size_t oldlen) | |
184 | { | |
3cf840f6 | 185 | void *newmem = kmalloc(newlen, GFP_KERNEL); |
e7f2aa34 | 186 | |
3cf840f6 | 187 | if (newmem && oldmem) |
e7f2aa34 GKH |
188 | memcpy(newmem, oldmem, min(oldlen, newlen)); |
189 | kfree(oldmem); | |
3cf840f6 DS |
190 | return newmem; |
191 | } | |
192 | ||
0707bb04 | 193 | static int doDevConfig(struct comedi_device *dev, struct comedi_devconfig *it) |
3cf840f6 | 194 | { |
a62a1764 | 195 | struct comedi_bond_private *devpriv = dev->private; |
3cf840f6 | 196 | int i; |
472dfe77 | 197 | struct comedi_device *devs_opened[COMEDI_NUM_BOARD_MINORS]; |
3cf840f6 DS |
198 | |
199 | memset(devs_opened, 0, sizeof(devs_opened)); | |
859171ca | 200 | devpriv->name[0] = 0; |
3cf840f6 DS |
201 | /* Loop through all comedi devices specified on the command-line, |
202 | building our device list */ | |
203 | for (i = 0; i < COMEDI_NDEVCONFOPTS && (!i || it->options[i]); ++i) { | |
204 | char file[] = "/dev/comediXXXXXX"; | |
205 | int minor = it->options[i]; | |
472dfe77 | 206 | struct comedi_device *d; |
3cf840f6 | 207 | int sdev = -1, nchans, tmp; |
246c5418 | 208 | struct BondedDevice *bdev = NULL; |
3cf840f6 | 209 | |
5d3aed74 | 210 | if (minor < 0 || minor >= COMEDI_NUM_BOARD_MINORS) { |
fdb2a66f HS |
211 | dev_err(dev->class_dev, |
212 | "Minor %d is invalid!\n", minor); | |
3cf840f6 DS |
213 | return 0; |
214 | } | |
215 | if (minor == dev->minor) { | |
fdb2a66f HS |
216 | dev_err(dev->class_dev, |
217 | "Cannot bond this driver to itself!\n"); | |
3cf840f6 DS |
218 | return 0; |
219 | } | |
220 | if (devs_opened[minor]) { | |
fdb2a66f HS |
221 | dev_err(dev->class_dev, |
222 | "Minor %d specified more than once!\n", minor); | |
3cf840f6 DS |
223 | return 0; |
224 | } | |
225 | ||
226 | snprintf(file, sizeof(file), "/dev/comedi%u", minor); | |
227 | file[sizeof(file) - 1] = 0; | |
228 | ||
229 | d = devs_opened[minor] = comedi_open(file); | |
230 | ||
231 | if (!d) { | |
fdb2a66f HS |
232 | dev_err(dev->class_dev, |
233 | "Minor %u could not be opened\n", minor); | |
3cf840f6 DS |
234 | return 0; |
235 | } | |
236 | ||
237 | /* Do DIO, as that's all we support now.. */ | |
238 | while ((sdev = comedi_find_subdevice_by_type(d, COMEDI_SUBD_DIO, | |
0a85b6f0 | 239 | sdev + 1)) > -1) { |
e7f2aa34 GKH |
240 | nchans = comedi_get_n_channels(d, sdev); |
241 | if (nchans <= 0) { | |
fdb2a66f HS |
242 | dev_err(dev->class_dev, |
243 | "comedi_get_n_channels() returned %d on minor %u subdev %d!\n", | |
244 | nchans, minor, sdev); | |
3cf840f6 DS |
245 | return 0; |
246 | } | |
247 | bdev = kmalloc(sizeof(*bdev), GFP_KERNEL); | |
248 | if (!bdev) { | |
fdb2a66f | 249 | dev_err(dev->class_dev, "Out of memory\n"); |
3cf840f6 DS |
250 | return 0; |
251 | } | |
252 | bdev->dev = d; | |
253 | bdev->minor = minor; | |
254 | bdev->subdev = sdev; | |
255 | bdev->subdev_type = COMEDI_SUBD_DIO; | |
256 | bdev->nchans = nchans; | |
257 | bdev->chanid_offset = devpriv->nchans; | |
258 | ||
259 | /* map channel id's to BondedDevice * pointer.. */ | |
260 | while (nchans--) | |
261 | devpriv->chanIdDevMap[devpriv->nchans++] = bdev; | |
262 | ||
e7f2aa34 GKH |
263 | /* Now put bdev pointer at end of devpriv->devs array |
264 | * list.. */ | |
3cf840f6 DS |
265 | |
266 | /* ergh.. ugly.. we need to realloc :( */ | |
267 | tmp = devpriv->ndevs * sizeof(bdev); | |
268 | devpriv->devs = | |
0a85b6f0 MT |
269 | Realloc(devpriv->devs, |
270 | ++devpriv->ndevs * sizeof(bdev), tmp); | |
3cf840f6 | 271 | if (!devpriv->devs) { |
fdb2a66f HS |
272 | dev_err(dev->class_dev, |
273 | "Could not allocate memory. Out of memory?\n"); | |
3cf840f6 DS |
274 | return 0; |
275 | } | |
276 | ||
277 | devpriv->devs[devpriv->ndevs - 1] = bdev; | |
278 | { | |
279 | /** Append dev:subdev to devpriv->name */ | |
280 | char buf[20]; | |
281 | int left = | |
0a85b6f0 | 282 | MAX_BOARD_NAME - strlen(devpriv->name) - 1; |
3cf840f6 | 283 | snprintf(buf, sizeof(buf), "%d:%d ", dev->minor, |
0a85b6f0 | 284 | bdev->subdev); |
3cf840f6 DS |
285 | buf[sizeof(buf) - 1] = 0; |
286 | strncat(devpriv->name, buf, left); | |
287 | } | |
288 | ||
289 | } | |
290 | } | |
291 | ||
292 | if (!devpriv->nchans) { | |
fdb2a66f | 293 | dev_err(dev->class_dev, "No channels found!\n"); |
3cf840f6 DS |
294 | return 0; |
295 | } | |
296 | ||
297 | return 1; | |
298 | } | |
299 | ||
ecdc3e0d HS |
300 | static int bonding_attach(struct comedi_device *dev, |
301 | struct comedi_devconfig *it) | |
3cf840f6 | 302 | { |
a62a1764 | 303 | struct comedi_bond_private *devpriv; |
ecdc3e0d | 304 | struct comedi_subdevice *s; |
8b6c5694 | 305 | int ret; |
ecdc3e0d | 306 | |
c34fa261 HS |
307 | devpriv = kzalloc(sizeof(*devpriv), GFP_KERNEL); |
308 | if (!devpriv) | |
309 | return -ENOMEM; | |
310 | dev->private = devpriv; | |
ecdc3e0d HS |
311 | |
312 | /* | |
a62a1764 | 313 | * Setup our bonding from config params.. sets up our private struct.. |
ecdc3e0d HS |
314 | */ |
315 | if (!doDevConfig(dev, it)) | |
316 | return -EINVAL; | |
317 | ||
ecdc3e0d HS |
318 | dev->board_name = devpriv->name; |
319 | ||
8b6c5694 HS |
320 | ret = comedi_alloc_subdevices(dev, 1); |
321 | if (ret) | |
322 | return ret; | |
ecdc3e0d | 323 | |
379585ab | 324 | s = &dev->subdevices[0]; |
ecdc3e0d HS |
325 | s->type = COMEDI_SUBD_DIO; |
326 | s->subdev_flags = SDF_READABLE | SDF_WRITABLE; | |
327 | s->n_chan = devpriv->nchans; | |
328 | s->maxdata = 1; | |
329 | s->range_table = &range_digital; | |
330 | s->insn_bits = bonding_dio_insn_bits; | |
331 | s->insn_config = bonding_dio_insn_config; | |
332 | ||
fdb2a66f HS |
333 | dev_info(dev->class_dev, |
334 | "%s: %s attached, %u channels from %u devices\n", | |
335 | dev->driver->driver_name, dev->board_name, | |
ecdc3e0d HS |
336 | devpriv->nchans, devpriv->ndevs); |
337 | ||
338 | return 1; | |
3cf840f6 DS |
339 | } |
340 | ||
484ecc95 | 341 | static void bonding_detach(struct comedi_device *dev) |
3cf840f6 | 342 | { |
a62a1764 | 343 | struct comedi_bond_private *devpriv = dev->private; |
484ecc95 HS |
344 | unsigned long devs_closed = 0; |
345 | ||
346 | if (devpriv) { | |
347 | while (devpriv->ndevs-- && devpriv->devs) { | |
348 | struct BondedDevice *bdev; | |
349 | ||
350 | bdev = devpriv->devs[devpriv->ndevs]; | |
351 | if (!bdev) | |
352 | continue; | |
353 | if (!(devs_closed & (0x1 << bdev->minor))) { | |
354 | comedi_close(bdev->dev); | |
355 | devs_closed |= (0x1 << bdev->minor); | |
356 | } | |
357 | kfree(bdev); | |
358 | } | |
359 | kfree(devpriv->devs); | |
360 | devpriv->devs = NULL; | |
361 | kfree(devpriv); | |
362 | dev->private = NULL; | |
363 | } | |
3cf840f6 DS |
364 | } |
365 | ||
ecdc3e0d HS |
366 | static struct comedi_driver bonding_driver = { |
367 | .driver_name = "comedi_bond", | |
368 | .module = THIS_MODULE, | |
369 | .attach = bonding_attach, | |
370 | .detach = bonding_detach, | |
ecdc3e0d HS |
371 | }; |
372 | module_comedi_driver(bonding_driver); | |
373 | ||
374 | MODULE_AUTHOR("Calin A. Culianu"); | |
fa38126b | 375 | MODULE_DESCRIPTION("comedi_bond: A driver for COMEDI to bond multiple COMEDI " |
ecdc3e0d HS |
376 | "devices together as one. In the words of John Lennon: " |
377 | "'And the world will live as one...'"); | |
378 | MODULE_LICENSE("GPL"); |