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_set_hw_dev(struct comedi_device *dev, struct device *hw_dev)
48 if (hw_dev == dev->hw_dev)
50 if (dev->hw_dev != NULL)
52 dev->hw_dev = get_device(hw_dev);
55 EXPORT_SYMBOL_GPL(comedi_set_hw_dev);
57 static void comedi_clear_hw_dev(struct comedi_device *dev)
59 put_device(dev->hw_dev);
63 int comedi_alloc_subdevices(struct comedi_device *dev, int num_subdevices)
65 struct comedi_subdevice *s;
68 if (num_subdevices < 1)
71 s = kcalloc(num_subdevices, sizeof(*s), GFP_KERNEL);
75 dev->n_subdevices = num_subdevices;
77 for (i = 0; i < num_subdevices; ++i) {
78 s = &dev->subdevices[i];
81 s->async_dma_dir = DMA_NONE;
82 spin_lock_init(&s->spin_lock);
87 EXPORT_SYMBOL_GPL(comedi_alloc_subdevices);
89 static void cleanup_device(struct comedi_device *dev)
92 struct comedi_subdevice *s;
94 if (dev->subdevices) {
95 for (i = 0; i < dev->n_subdevices; i++) {
96 s = &dev->subdevices[i];
97 comedi_free_subdevice_minor(s);
99 comedi_buf_alloc(dev, s, 0);
103 kfree(dev->subdevices);
104 dev->subdevices = NULL;
105 dev->n_subdevices = 0;
110 dev->board_name = NULL;
111 dev->board_ptr = NULL;
114 dev->read_subdev = NULL;
115 dev->write_subdev = NULL;
118 comedi_clear_hw_dev(dev);
121 static void __comedi_device_detach(struct comedi_device *dev)
125 dev->driver->detach(dev);
127 dev_warn(dev->class_dev,
128 "BUG: dev->driver=NULL in comedi_device_detach()\n");
132 void comedi_device_detach(struct comedi_device *dev)
136 __comedi_device_detach(dev);
139 static int poll_invalid(struct comedi_device *dev, struct comedi_subdevice *s)
144 int insn_inval(struct comedi_device *dev, struct comedi_subdevice *s,
145 struct comedi_insn *insn, unsigned int *data)
150 static int insn_rw_emulate_bits(struct comedi_device *dev,
151 struct comedi_subdevice *s,
152 struct comedi_insn *insn, unsigned int *data)
154 struct comedi_insn new_insn;
156 static const unsigned channels_per_bitfield = 32;
158 unsigned chan = CR_CHAN(insn->chanspec);
159 const unsigned base_bitfield_channel =
160 (chan < channels_per_bitfield) ? 0 : chan;
161 unsigned int new_data[2];
162 memset(new_data, 0, sizeof(new_data));
163 memset(&new_insn, 0, sizeof(new_insn));
164 new_insn.insn = INSN_BITS;
165 new_insn.chanspec = base_bitfield_channel;
167 new_insn.subdev = insn->subdev;
169 if (insn->insn == INSN_WRITE) {
170 if (!(s->subdev_flags & SDF_WRITABLE))
172 new_data[0] = 1 << (chan - base_bitfield_channel); /* mask */
173 new_data[1] = data[0] ? (1 << (chan - base_bitfield_channel))
177 ret = s->insn_bits(dev, s, &new_insn, new_data);
181 if (insn->insn == INSN_READ)
182 data[0] = (new_data[1] >> (chan - base_bitfield_channel)) & 1;
187 static int __comedi_device_postconfig_async(struct comedi_device *dev,
188 struct comedi_subdevice *s)
190 struct comedi_async *async;
191 unsigned int buf_size;
194 if ((s->subdev_flags & (SDF_CMD_READ | SDF_CMD_WRITE)) == 0) {
195 dev_warn(dev->class_dev,
196 "async subdevices must support SDF_CMD_READ or SDF_CMD_WRITE\n");
199 if (!s->do_cmdtest) {
200 dev_warn(dev->class_dev,
201 "async subdevices must have a do_cmdtest() function\n");
205 async = kzalloc(sizeof(*async), GFP_KERNEL);
209 init_waitqueue_head(&async->wait_head);
210 async->subdevice = s;
213 async->max_bufsize = comedi_default_buf_maxsize_kb * 1024;
214 buf_size = comedi_default_buf_size_kb * 1024;
215 if (buf_size > async->max_bufsize)
216 buf_size = async->max_bufsize;
218 if (comedi_buf_alloc(dev, s, buf_size) < 0) {
219 dev_warn(dev->class_dev, "Buffer allocation failed\n");
223 ret = s->buf_change(dev, s, buf_size);
228 comedi_alloc_subdevice_minor(s);
233 static int __comedi_device_postconfig(struct comedi_device *dev)
235 struct comedi_subdevice *s;
239 for (i = 0; i < dev->n_subdevices; i++) {
240 s = &dev->subdevices[i];
242 if (s->type == COMEDI_SUBD_UNUSED)
245 if (s->len_chanlist == 0)
249 ret = __comedi_device_postconfig_async(dev, s);
254 if (!s->range_table && !s->range_table_list)
255 s->range_table = &range_unknown;
257 if (!s->insn_read && s->insn_bits)
258 s->insn_read = insn_rw_emulate_bits;
259 if (!s->insn_write && s->insn_bits)
260 s->insn_write = insn_rw_emulate_bits;
263 s->insn_read = insn_inval;
265 s->insn_write = insn_inval;
267 s->insn_bits = insn_inval;
269 s->insn_config = insn_inval;
272 s->poll = poll_invalid;
278 /* do a little post-config cleanup */
279 /* called with module refcount incremented, decrements it */
280 static int comedi_device_postconfig(struct comedi_device *dev)
282 int ret = __comedi_device_postconfig(dev);
283 module_put(dev->driver->module);
285 __comedi_device_detach(dev);
288 if (!dev->board_name) {
289 dev_warn(dev->class_dev, "BUG: dev->board_name=NULL\n");
290 dev->board_name = "BUG";
298 * Generic recognize function for drivers that register their supported
301 * 'driv->board_name' points to a 'const char *' member within the
302 * zeroth element of an array of some private board information
303 * structure, say 'struct foo_board' containing a member 'const char
304 * *board_name' that is initialized to point to a board name string that
305 * is one of the candidates matched against this function's 'name'
308 * 'driv->offset' is the size of the private board information
309 * structure, say 'sizeof(struct foo_board)', and 'driv->num_names' is
310 * the length of the array of private board information structures.
312 * If one of the board names in the array of private board information
313 * structures matches the name supplied to this function, the function
314 * returns a pointer to the pointer to the board name, otherwise it
315 * returns NULL. The return value ends up in the 'board_ptr' member of
316 * a 'struct comedi_device' that the low-level comedi driver's
317 * 'attach()' hook can convert to a point to a particular element of its
318 * array of private board information structures by subtracting the
319 * offset of the member that points to the board name. (No subtraction
320 * is required if the board name pointer is the first member of the
321 * private board information structure, which is generally the case.)
323 static void *comedi_recognize(struct comedi_driver *driv, const char *name)
325 char **name_ptr = (char **)driv->board_name;
328 for (i = 0; i < driv->num_names; i++) {
329 if (strcmp(*name_ptr, name) == 0)
331 name_ptr = (void *)name_ptr + driv->offset;
337 static void comedi_report_boards(struct comedi_driver *driv)
340 const char *const *name_ptr;
342 pr_info("comedi: valid board names for %s driver are:\n",
345 name_ptr = driv->board_name;
346 for (i = 0; i < driv->num_names; i++) {
347 pr_info(" %s\n", *name_ptr);
348 name_ptr = (const char **)((char *)name_ptr + driv->offset);
351 if (driv->num_names == 0)
352 pr_info(" %s\n", driv->driver_name);
355 int comedi_device_attach(struct comedi_device *dev, struct comedi_devconfig *it)
357 struct comedi_driver *driv;
363 for (driv = comedi_drivers; driv; driv = driv->next) {
364 if (!try_module_get(driv->module))
366 if (driv->num_names) {
367 dev->board_ptr = comedi_recognize(driv, it->board_name);
370 } else if (strcmp(driv->driver_name, it->board_name) == 0)
372 module_put(driv->module);
375 /* recognize has failed if we get here */
376 /* report valid board names before returning error */
377 for (driv = comedi_drivers; driv; driv = driv->next) {
378 if (!try_module_get(driv->module))
380 comedi_report_boards(driv);
381 module_put(driv->module);
385 if (driv->attach == NULL) {
386 /* driver does not support manual configuration */
387 dev_warn(dev->class_dev,
388 "driver '%s' does not support attach using comedi_config\n",
390 module_put(driv->module);
393 /* initialize dev->driver here so
394 * comedi_error() can be called from attach */
396 ret = driv->attach(dev, it);
398 module_put(dev->driver->module);
399 __comedi_device_detach(dev);
402 return comedi_device_postconfig(dev);
405 int comedi_auto_config(struct device *hardware_device,
406 struct comedi_driver *driver, unsigned long context)
409 struct comedi_device *comedi_dev;
412 if (!driver->auto_attach) {
413 dev_warn(hardware_device,
414 "BUG! comedi driver '%s' has no auto_attach handler\n",
415 driver->driver_name);
419 minor = comedi_alloc_board_minor(hardware_device);
423 comedi_dev = comedi_dev_from_minor(minor);
425 mutex_lock(&comedi_dev->mutex);
426 if (comedi_dev->attached)
428 else if (!try_module_get(driver->module))
431 comedi_set_hw_dev(comedi_dev, hardware_device);
432 comedi_dev->driver = driver;
433 ret = driver->auto_attach(comedi_dev, context);
435 module_put(driver->module);
436 __comedi_device_detach(comedi_dev);
438 ret = comedi_device_postconfig(comedi_dev);
441 mutex_unlock(&comedi_dev->mutex);
444 comedi_free_board_minor(minor);
447 EXPORT_SYMBOL_GPL(comedi_auto_config);
449 void comedi_auto_unconfig(struct device *hardware_device)
453 if (hardware_device == NULL)
455 minor = comedi_find_board_minor(hardware_device);
458 comedi_free_board_minor(minor);
460 EXPORT_SYMBOL_GPL(comedi_auto_unconfig);
462 int comedi_driver_register(struct comedi_driver *driver)
464 driver->next = comedi_drivers;
465 comedi_drivers = driver;
469 EXPORT_SYMBOL(comedi_driver_register);
471 int comedi_driver_unregister(struct comedi_driver *driver)
473 struct comedi_driver *prev;
476 /* check for devices using this driver */
477 for (i = 0; i < COMEDI_NUM_BOARD_MINORS; i++) {
478 struct comedi_device *dev = comedi_dev_from_minor(i);
483 mutex_lock(&dev->mutex);
484 if (dev->attached && dev->driver == driver) {
486 dev_warn(dev->class_dev,
487 "BUG! detaching device with use_count=%d\n",
489 comedi_device_detach(dev);
491 mutex_unlock(&dev->mutex);
494 if (comedi_drivers == driver) {
495 comedi_drivers = driver->next;
499 for (prev = comedi_drivers; prev->next; prev = prev->next) {
500 if (prev->next == driver) {
501 prev->next = driver->next;
507 EXPORT_SYMBOL(comedi_driver_unregister);