3 functions for manipulating drivers
5 COMEDI - Linux Control and Measurement Device Interface
6 Copyright (C) 1997-2000 David A. Schleef <ds@schleef.org>
8 This program is free software; you can redistribute it and/or modify
9 it under the terms of the GNU General Public License as published by
10 the Free Software Foundation; either version 2 of the License, or
11 (at your option) any later version.
13 This program is distributed in the hope that it will be useful,
14 but WITHOUT ANY WARRANTY; without even the implied warranty of
15 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 GNU General Public License for more details.
18 You should have received a copy of the GNU General Public License
19 along with this program; if not, write to the Free Software
20 Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
24 #include <linux/device.h>
25 #include <linux/module.h>
26 #include <linux/errno.h>
27 #include <linux/kconfig.h>
28 #include <linux/kernel.h>
29 #include <linux/sched.h>
30 #include <linux/fcntl.h>
31 #include <linux/delay.h>
32 #include <linux/ioport.h>
34 #include <linux/slab.h>
35 #include <linux/highmem.h> /* for SuSE brokenness */
36 #include <linux/vmalloc.h>
37 #include <linux/cdev.h>
38 #include <linux/dma-mapping.h>
41 #include "comedidev.h"
42 #include "comedi_internal.h"
44 struct comedi_driver *comedi_drivers;
46 int comedi_alloc_subdevices(struct comedi_device *dev, int num_subdevices)
48 struct comedi_subdevice *s;
51 if (num_subdevices < 1)
54 s = kcalloc(num_subdevices, sizeof(*s), GFP_KERNEL);
58 dev->n_subdevices = num_subdevices;
60 for (i = 0; i < num_subdevices; ++i) {
61 s = &dev->subdevices[i];
64 s->async_dma_dir = DMA_NONE;
65 spin_lock_init(&s->spin_lock);
70 EXPORT_SYMBOL_GPL(comedi_alloc_subdevices);
72 static void cleanup_device(struct comedi_device *dev)
75 struct comedi_subdevice *s;
77 if (dev->subdevices) {
78 for (i = 0; i < dev->n_subdevices; i++) {
79 s = &dev->subdevices[i];
80 comedi_free_subdevice_minor(s);
82 comedi_buf_alloc(dev, s, 0);
86 kfree(dev->subdevices);
87 dev->subdevices = NULL;
88 dev->n_subdevices = 0;
93 dev->board_name = NULL;
94 dev->board_ptr = NULL;
97 dev->read_subdev = NULL;
98 dev->write_subdev = NULL;
101 comedi_set_hw_dev(dev, NULL);
104 static void __comedi_device_detach(struct comedi_device *dev)
108 dev->driver->detach(dev);
110 dev_warn(dev->class_dev,
111 "BUG: dev->driver=NULL in comedi_device_detach()\n");
115 void comedi_device_detach(struct comedi_device *dev)
119 __comedi_device_detach(dev);
122 static int poll_invalid(struct comedi_device *dev, struct comedi_subdevice *s)
127 int insn_inval(struct comedi_device *dev, struct comedi_subdevice *s,
128 struct comedi_insn *insn, unsigned int *data)
133 static int insn_rw_emulate_bits(struct comedi_device *dev,
134 struct comedi_subdevice *s,
135 struct comedi_insn *insn, unsigned int *data)
137 struct comedi_insn new_insn;
139 static const unsigned channels_per_bitfield = 32;
141 unsigned chan = CR_CHAN(insn->chanspec);
142 const unsigned base_bitfield_channel =
143 (chan < channels_per_bitfield) ? 0 : chan;
144 unsigned int new_data[2];
145 memset(new_data, 0, sizeof(new_data));
146 memset(&new_insn, 0, sizeof(new_insn));
147 new_insn.insn = INSN_BITS;
148 new_insn.chanspec = base_bitfield_channel;
150 new_insn.subdev = insn->subdev;
152 if (insn->insn == INSN_WRITE) {
153 if (!(s->subdev_flags & SDF_WRITABLE))
155 new_data[0] = 1 << (chan - base_bitfield_channel); /* mask */
156 new_data[1] = data[0] ? (1 << (chan - base_bitfield_channel))
160 ret = s->insn_bits(dev, s, &new_insn, new_data);
164 if (insn->insn == INSN_READ)
165 data[0] = (new_data[1] >> (chan - base_bitfield_channel)) & 1;
170 static int __comedi_device_postconfig_async(struct comedi_device *dev,
171 struct comedi_subdevice *s)
173 struct comedi_async *async;
174 unsigned int buf_size;
177 if ((s->subdev_flags & (SDF_CMD_READ | SDF_CMD_WRITE)) == 0) {
178 dev_warn(dev->class_dev,
179 "async subdevices must support SDF_CMD_READ or SDF_CMD_WRITE\n");
182 if (!s->do_cmdtest) {
183 dev_warn(dev->class_dev,
184 "async subdevices must have a do_cmdtest() function\n");
188 async = kzalloc(sizeof(*async), GFP_KERNEL);
190 dev_warn(dev->class_dev, "failed to allocate async struct\n");
193 init_waitqueue_head(&async->wait_head);
194 async->subdevice = s;
197 async->max_bufsize = comedi_default_buf_maxsize_kb * 1024;
198 buf_size = comedi_default_buf_size_kb * 1024;
199 if (buf_size > async->max_bufsize)
200 buf_size = async->max_bufsize;
202 if (comedi_buf_alloc(dev, s, buf_size) < 0) {
203 dev_warn(dev->class_dev, "Buffer allocation failed\n");
207 ret = s->buf_change(dev, s, buf_size);
212 comedi_alloc_subdevice_minor(s);
217 static int __comedi_device_postconfig(struct comedi_device *dev)
219 struct comedi_subdevice *s;
223 for (i = 0; i < dev->n_subdevices; i++) {
224 s = &dev->subdevices[i];
226 if (s->type == COMEDI_SUBD_UNUSED)
229 if (s->len_chanlist == 0)
233 ret = __comedi_device_postconfig_async(dev, s);
238 if (!s->range_table && !s->range_table_list)
239 s->range_table = &range_unknown;
241 if (!s->insn_read && s->insn_bits)
242 s->insn_read = insn_rw_emulate_bits;
243 if (!s->insn_write && s->insn_bits)
244 s->insn_write = insn_rw_emulate_bits;
247 s->insn_read = insn_inval;
249 s->insn_write = insn_inval;
251 s->insn_bits = insn_inval;
253 s->insn_config = insn_inval;
256 s->poll = poll_invalid;
262 /* do a little post-config cleanup */
263 /* called with module refcount incremented, decrements it */
264 static int comedi_device_postconfig(struct comedi_device *dev)
266 int ret = __comedi_device_postconfig(dev);
267 module_put(dev->driver->module);
269 __comedi_device_detach(dev);
272 if (!dev->board_name) {
273 dev_warn(dev->class_dev, "BUG: dev->board_name=NULL\n");
274 dev->board_name = "BUG";
282 * Generic recognize function for drivers that register their supported
285 * 'driv->board_name' points to a 'const char *' member within the
286 * zeroth element of an array of some private board information
287 * structure, say 'struct foo_board' containing a member 'const char
288 * *board_name' that is initialized to point to a board name string that
289 * is one of the candidates matched against this function's 'name'
292 * 'driv->offset' is the size of the private board information
293 * structure, say 'sizeof(struct foo_board)', and 'driv->num_names' is
294 * the length of the array of private board information structures.
296 * If one of the board names in the array of private board information
297 * structures matches the name supplied to this function, the function
298 * returns a pointer to the pointer to the board name, otherwise it
299 * returns NULL. The return value ends up in the 'board_ptr' member of
300 * a 'struct comedi_device' that the low-level comedi driver's
301 * 'attach()' hook can convert to a point to a particular element of its
302 * array of private board information structures by subtracting the
303 * offset of the member that points to the board name. (No subtraction
304 * is required if the board name pointer is the first member of the
305 * private board information structure, which is generally the case.)
307 static void *comedi_recognize(struct comedi_driver *driv, const char *name)
309 char **name_ptr = (char **)driv->board_name;
312 for (i = 0; i < driv->num_names; i++) {
313 if (strcmp(*name_ptr, name) == 0)
315 name_ptr = (void *)name_ptr + driv->offset;
321 static void comedi_report_boards(struct comedi_driver *driv)
324 const char *const *name_ptr;
326 pr_info("comedi: valid board names for %s driver are:\n",
329 name_ptr = driv->board_name;
330 for (i = 0; i < driv->num_names; i++) {
331 pr_info(" %s\n", *name_ptr);
332 name_ptr = (const char **)((char *)name_ptr + driv->offset);
335 if (driv->num_names == 0)
336 pr_info(" %s\n", driv->driver_name);
339 int comedi_device_attach(struct comedi_device *dev, struct comedi_devconfig *it)
341 struct comedi_driver *driv;
347 for (driv = comedi_drivers; driv; driv = driv->next) {
348 if (!try_module_get(driv->module))
350 if (driv->num_names) {
351 dev->board_ptr = comedi_recognize(driv, it->board_name);
354 } else if (strcmp(driv->driver_name, it->board_name) == 0)
356 module_put(driv->module);
359 /* recognize has failed if we get here */
360 /* report valid board names before returning error */
361 for (driv = comedi_drivers; driv; driv = driv->next) {
362 if (!try_module_get(driv->module))
364 comedi_report_boards(driv);
365 module_put(driv->module);
369 if (driv->attach == NULL) {
370 /* driver does not support manual configuration */
371 dev_warn(dev->class_dev,
372 "driver '%s' does not support attach using comedi_config\n",
374 module_put(driv->module);
377 /* initialize dev->driver here so
378 * comedi_error() can be called from attach */
380 ret = driv->attach(dev, it);
382 module_put(dev->driver->module);
383 __comedi_device_detach(dev);
386 return comedi_device_postconfig(dev);
389 int comedi_auto_config(struct device *hardware_device,
390 struct comedi_driver *driver, unsigned long context)
393 struct comedi_device *comedi_dev;
396 if (!comedi_autoconfig)
399 if (!driver->auto_attach) {
400 dev_warn(hardware_device,
401 "BUG! comedi driver '%s' has no auto_attach handler\n",
402 driver->driver_name);
406 minor = comedi_alloc_board_minor(hardware_device);
410 comedi_dev = comedi_dev_from_minor(minor);
412 mutex_lock(&comedi_dev->mutex);
413 if (comedi_dev->attached)
415 else if (!try_module_get(driver->module))
418 comedi_set_hw_dev(comedi_dev, hardware_device);
419 comedi_dev->driver = driver;
420 ret = driver->auto_attach(comedi_dev, context);
422 module_put(driver->module);
423 __comedi_device_detach(comedi_dev);
425 ret = comedi_device_postconfig(comedi_dev);
428 mutex_unlock(&comedi_dev->mutex);
431 comedi_free_board_minor(minor);
434 EXPORT_SYMBOL_GPL(comedi_auto_config);
436 void comedi_auto_unconfig(struct device *hardware_device)
440 if (hardware_device == NULL)
442 minor = comedi_find_board_minor(hardware_device);
445 comedi_free_board_minor(minor);
447 EXPORT_SYMBOL_GPL(comedi_auto_unconfig);
449 int comedi_driver_register(struct comedi_driver *driver)
451 driver->next = comedi_drivers;
452 comedi_drivers = driver;
456 EXPORT_SYMBOL(comedi_driver_register);
458 int comedi_driver_unregister(struct comedi_driver *driver)
460 struct comedi_driver *prev;
463 /* check for devices using this driver */
464 for (i = 0; i < COMEDI_NUM_BOARD_MINORS; i++) {
465 struct comedi_device *dev = comedi_dev_from_minor(i);
470 mutex_lock(&dev->mutex);
471 if (dev->attached && dev->driver == driver) {
473 dev_warn(dev->class_dev,
474 "BUG! detaching device with use_count=%d\n",
476 comedi_device_detach(dev);
478 mutex_unlock(&dev->mutex);
481 if (comedi_drivers == driver) {
482 comedi_drivers = driver->next;
486 for (prev = comedi_drivers; prev->next; prev = prev->next) {
487 if (prev->next == driver) {
488 prev->next = driver->next;
494 EXPORT_SYMBOL(comedi_driver_unregister);