1 files changed, 188 insertions, 671 deletions

diff --git a/drivers/staging/comedi/drivers.c b/drivers/staging/comedi/drivers.c
index 50cf498698e2..64be7c5e891e 100644
--- a/drivers/staging/comedi/drivers.c
+++ b/drivers/staging/comedi/drivers.c
@@ -23,8 +23,6 @@
 
 #include <linux/device.h>
 #include <linux/module.h>
-#include <linux/pci.h>
-#include <linux/usb.h>
 #include <linux/errno.h>
 #include <linux/kconfig.h>
 #include <linux/kernel.h>
@@ -43,16 +41,25 @@
 #include "comedidev.h"
 #include "comedi_internal.h"
 
-static int postconfig(struct comedi_device *dev);
-static int insn_rw_emulate_bits(struct comedi_device *dev,
-				struct comedi_subdevice *s,
-				struct comedi_insn *insn, unsigned int *data);
-static void *comedi_recognize(struct comedi_driver *driv, const char *name);
-static void comedi_report_boards(struct comedi_driver *driv);
-static int poll_invalid(struct comedi_device *dev, struct comedi_subdevice *s);
-
 struct comedi_driver *comedi_drivers;
 
+int comedi_set_hw_dev(struct comedi_device *dev, struct device *hw_dev)
+{
+	if (hw_dev == dev->hw_dev)
+		return 0;
+	if (dev->hw_dev != NULL)
+		return -EEXIST;
+	dev->hw_dev = get_device(hw_dev);
+	return 0;
+}
+EXPORT_SYMBOL_GPL(comedi_set_hw_dev);
+
+static void comedi_clear_hw_dev(struct comedi_device *dev)
+{
+	put_device(dev->hw_dev);
+	dev->hw_dev = NULL;
+}
+
 int comedi_alloc_subdevices(struct comedi_device *dev, int num_subdevices)
 {
 	struct comedi_subdevice *s;
@@ -70,6 +77,7 @@ int comedi_alloc_subdevices(struct comedi_device *dev, int num_subdevices)
 	for (i = 0; i < num_subdevices; ++i) {
 		s = &dev->subdevices[i];
 		s->device = dev;
+		s->index = i;
 		s->async_dma_dir = DMA_NONE;
 		spin_lock_init(&s->spin_lock);
 		s->minor = -1;
@@ -107,7 +115,7 @@ static void cleanup_device(struct comedi_device *dev)
 	dev->write_subdev = NULL;
 	dev->open = NULL;
 	dev->close = NULL;
-	comedi_set_hw_dev(dev, NULL);
+	comedi_clear_hw_dev(dev);
 }
 
 static void __comedi_device_detach(struct comedi_device *dev)
@@ -128,131 +136,105 @@ void comedi_device_detach(struct comedi_device *dev)
 	__comedi_device_detach(dev);
 }
 
-/* do a little post-config cleanup */
-/* called with module refcount incremented, decrements it */
-static int comedi_device_postconfig(struct comedi_device *dev)
+static int poll_invalid(struct comedi_device *dev, struct comedi_subdevice *s)
 {
-	int ret = postconfig(dev);
-	module_put(dev->driver->module);
-	if (ret < 0) {
-		__comedi_device_detach(dev);
-		return ret;
-	}
-	if (!dev->board_name) {
-		dev_warn(dev->class_dev, "BUG: dev->board_name=NULL\n");
-		dev->board_name = "BUG";
-	}
-	smp_wmb();
-	dev->attached = 1;
-	return 0;
+	return -EINVAL;
 }
 
-int comedi_device_attach(struct comedi_device *dev, struct comedi_devconfig *it)
+int insn_inval(struct comedi_device *dev, struct comedi_subdevice *s,
+	       struct comedi_insn *insn, unsigned int *data)
 {
-	struct comedi_driver *driv;
+	return -EINVAL;
+}
+
+static int insn_rw_emulate_bits(struct comedi_device *dev,
+				struct comedi_subdevice *s,
+				struct comedi_insn *insn, unsigned int *data)
+{
+	struct comedi_insn new_insn;
 	int ret;
+	static const unsigned channels_per_bitfield = 32;
 
-	if (dev->attached)
-		return -EBUSY;
+	unsigned chan = CR_CHAN(insn->chanspec);
+	const unsigned base_bitfield_channel =
+	    (chan < channels_per_bitfield) ? 0 : chan;
+	unsigned int new_data[2];
+	memset(new_data, 0, sizeof(new_data));
+	memset(&new_insn, 0, sizeof(new_insn));
+	new_insn.insn = INSN_BITS;
+	new_insn.chanspec = base_bitfield_channel;
+	new_insn.n = 2;
+	new_insn.subdev = insn->subdev;
 
-	for (driv = comedi_drivers; driv; driv = driv->next) {
-		if (!try_module_get(driv->module))
-			continue;
-		if (driv->num_names) {
-			dev->board_ptr = comedi_recognize(driv, it->board_name);
-			if (dev->board_ptr)
-				break;
-		} else if (strcmp(driv->driver_name, it->board_name) == 0)
-			break;
-		module_put(driv->module);
-	}
-	if (driv == NULL) {
-		/*  recognize has failed if we get here */
-		/*  report valid board names before returning error */
-		for (driv = comedi_drivers; driv; driv = driv->next) {
-			if (!try_module_get(driv->module))
-				continue;
-			comedi_report_boards(driv);
-			module_put(driv->module);
-		}
-		return -EIO;
-	}
-	if (driv->attach == NULL) {
-		/* driver does not support manual configuration */
-		dev_warn(dev->class_dev,
-			 "driver '%s' does not support attach using comedi_config\n",
-			 driv->driver_name);
-		module_put(driv->module);
-		return -ENOSYS;
+	if (insn->insn == INSN_WRITE) {
+		if (!(s->subdev_flags & SDF_WRITABLE))
+			return -EINVAL;
+		new_data[0] = 1 << (chan - base_bitfield_channel); /* mask */
+		new_data[1] = data[0] ? (1 << (chan - base_bitfield_channel))
+			      : 0; /* bits */
 	}
-	/* initialize dev->driver here so
-	 * comedi_error() can be called from attach */
-	dev->driver = driv;
-	ret = driv->attach(dev, it);
-	if (ret < 0) {
-		module_put(dev->driver->module);
-		__comedi_device_detach(dev);
+
+	ret = s->insn_bits(dev, s, &new_insn, new_data);
+	if (ret < 0)
 		return ret;
-	}
-	return comedi_device_postconfig(dev);
-}
 
-int comedi_driver_register(struct comedi_driver *driver)
-{
-	driver->next = comedi_drivers;
-	comedi_drivers = driver;
+	if (insn->insn == INSN_READ)
+		data[0] = (new_data[1] >> (chan - base_bitfield_channel)) & 1;
 
-	return 0;
+	return 1;
 }
-EXPORT_SYMBOL(comedi_driver_register);
 
-int comedi_driver_unregister(struct comedi_driver *driver)
+static int __comedi_device_postconfig_async(struct comedi_device *dev,
+					    struct comedi_subdevice *s)
 {
-	struct comedi_driver *prev;
-	int i;
+	struct comedi_async *async;
+	unsigned int buf_size;
+	int ret;
 
-	/* check for devices using this driver */
-	for (i = 0; i < COMEDI_NUM_BOARD_MINORS; i++) {
-		struct comedi_device_file_info *dev_file_info =
-		    comedi_get_device_file_info(i);
-		struct comedi_device *dev;
+	if ((s->subdev_flags & (SDF_CMD_READ | SDF_CMD_WRITE)) == 0) {
+		dev_warn(dev->class_dev,
+			 "async subdevices must support SDF_CMD_READ or SDF_CMD_WRITE\n");
+		return -EINVAL;
+	}
+	if (!s->do_cmdtest) {
+		dev_warn(dev->class_dev,
+			 "async subdevices must have a do_cmdtest() function\n");
+		return -EINVAL;
+	}
 
-		if (dev_file_info == NULL)
-			continue;
-		dev = dev_file_info->device;
+	async = kzalloc(sizeof(*async), GFP_KERNEL);
+	if (!async)
+		return -ENOMEM;
 
-		mutex_lock(&dev->mutex);
-		if (dev->attached && dev->driver == driver) {
-			if (dev->use_count)
-				dev_warn(dev->class_dev,
-					 "BUG! detaching device with use_count=%d\n",
-					 dev->use_count);
-			comedi_device_detach(dev);
-		}
-		mutex_unlock(&dev->mutex);
-	}
+	init_waitqueue_head(&async->wait_head);
+	async->subdevice = s;
+	s->async = async;
 
-	if (comedi_drivers == driver) {
-		comedi_drivers = driver->next;
-		return 0;
-	}
+	async->max_bufsize = comedi_default_buf_maxsize_kb * 1024;
+	buf_size = comedi_default_buf_size_kb * 1024;
+	if (buf_size > async->max_bufsize)
+		buf_size = async->max_bufsize;
 
-	for (prev = comedi_drivers; prev->next; prev = prev->next) {
-		if (prev->next == driver) {
-			prev->next = driver->next;
-			return 0;
-		}
+	if (comedi_buf_alloc(dev, s, buf_size) < 0) {
+		dev_warn(dev->class_dev, "Buffer allocation failed\n");
+		return -ENOMEM;
 	}
-	return -EINVAL;
+	if (s->buf_change) {
+		ret = s->buf_change(dev, s, buf_size);
+		if (ret < 0)
+			return ret;
+	}
+
+	comedi_alloc_subdevice_minor(s);
+
+	return 0;
 }
-EXPORT_SYMBOL(comedi_driver_unregister);
 
-static int postconfig(struct comedi_device *dev)
+static int __comedi_device_postconfig(struct comedi_device *dev)
 {
-	int i;
 	struct comedi_subdevice *s;
-	struct comedi_async *async = NULL;
 	int ret;
+	int i;
 
 	for (i = 0; i < dev->n_subdevices; i++) {
 		s = &dev->subdevices[i];
@@ -264,42 +246,9 @@ static int postconfig(struct comedi_device *dev)
 			s->len_chanlist = 1;
 
 		if (s->do_cmd) {
-			unsigned int buf_size;
-
-			BUG_ON((s->subdev_flags & (SDF_CMD_READ |
-						   SDF_CMD_WRITE)) == 0);
-			BUG_ON(!s->do_cmdtest);
-
-			async =
-			    kzalloc(sizeof(struct comedi_async), GFP_KERNEL);
-			if (async == NULL) {
-				dev_warn(dev->class_dev,
-					 "failed to allocate async struct\n");
-				return -ENOMEM;
-			}
-			init_waitqueue_head(&async->wait_head);
-			async->subdevice = s;
-			s->async = async;
-
-			async->max_bufsize =
-				comedi_default_buf_maxsize_kb * 1024;
-			buf_size = comedi_default_buf_size_kb * 1024;
-			if (buf_size > async->max_bufsize)
-				buf_size = async->max_bufsize;
-
-			async->prealloc_buf = NULL;
-			async->prealloc_bufsz = 0;
-			if (comedi_buf_alloc(dev, s, buf_size) < 0) {
-				dev_warn(dev->class_dev,
-					 "Buffer allocation failed\n");
-				return -ENOMEM;
-			}
-			if (s->buf_change) {
-				ret = s->buf_change(dev, s, buf_size);
-				if (ret < 0)
-					return ret;
-			}
-			comedi_alloc_subdevice_minor(dev, s);
+			ret = __comedi_device_postconfig_async(dev, s);
+			if (ret)
+				return ret;
 		}
 
 		if (!s->range_table && !s->range_table_list)
@@ -326,6 +275,25 @@ static int postconfig(struct comedi_device *dev)
 	return 0;
 }
 
+/* do a little post-config cleanup */
+/* called with module refcount incremented, decrements it */
+static int comedi_device_postconfig(struct comedi_device *dev)
+{
+	int ret = __comedi_device_postconfig(dev);
+	module_put(dev->driver->module);
+	if (ret < 0) {
+		__comedi_device_detach(dev);
+		return ret;
+	}
+	if (!dev->board_name) {
+		dev_warn(dev->class_dev, "BUG: dev->board_name=NULL\n");
+		dev->board_name = "BUG";
+	}
+	smp_wmb();
+	dev->attached = 1;
+	return 0;
+}
+
 /*
  * Generic recognize function for drivers that register their supported
  * board names.
@@ -384,463 +352,63 @@ static void comedi_report_boards(struct comedi_driver *driv)
 		pr_info(" %s\n", driv->driver_name);
 }
 
-static int poll_invalid(struct comedi_device *dev, struct comedi_subdevice *s)
-{
-	return -EINVAL;
-}
-
-int insn_inval(struct comedi_device *dev, struct comedi_subdevice *s,
-	       struct comedi_insn *insn, unsigned int *data)
-{
-	return -EINVAL;
-}
-
-static int insn_rw_emulate_bits(struct comedi_device *dev,
-				struct comedi_subdevice *s,
-				struct comedi_insn *insn, unsigned int *data)
+int comedi_device_attach(struct comedi_device *dev, struct comedi_devconfig *it)
 {
-	struct comedi_insn new_insn;
+	struct comedi_driver *driv;
 	int ret;
-	static const unsigned channels_per_bitfield = 32;
-
-	unsigned chan = CR_CHAN(insn->chanspec);
-	const unsigned base_bitfield_channel =
-	    (chan < channels_per_bitfield) ? 0 : chan;
-	unsigned int new_data[2];
-	memset(new_data, 0, sizeof(new_data));
-	memset(&new_insn, 0, sizeof(new_insn));
-	new_insn.insn = INSN_BITS;
-	new_insn.chanspec = base_bitfield_channel;
-	new_insn.n = 2;
-	new_insn.subdev = insn->subdev;
 
-	if (insn->insn == INSN_WRITE) {
-		if (!(s->subdev_flags & SDF_WRITABLE))
-			return -EINVAL;
-		new_data[0] = 1 << (chan - base_bitfield_channel); /* mask */
-		new_data[1] = data[0] ? (1 << (chan - base_bitfield_channel))
-			      : 0; /* bits */
-	}
-
-	ret = s->insn_bits(dev, s, &new_insn, new_data);
-	if (ret < 0)
-		return ret;
-
-	if (insn->insn == INSN_READ)
-		data[0] = (new_data[1] >> (chan - base_bitfield_channel)) & 1;
-
-	return 1;
-}
-
-int comedi_buf_alloc(struct comedi_device *dev, struct comedi_subdevice *s,
-		     unsigned long new_size)
-{
-	struct comedi_async *async = s->async;
-
-	/* Round up new_size to multiple of PAGE_SIZE */
-	new_size = (new_size + PAGE_SIZE - 1) & PAGE_MASK;
-
-	/* if no change is required, do nothing */
-	if (async->prealloc_buf && async->prealloc_bufsz == new_size)
-		return 0;
-
-	/*  deallocate old buffer */
-	if (async->prealloc_buf) {
-		vunmap(async->prealloc_buf);
-		async->prealloc_buf = NULL;
-		async->prealloc_bufsz = 0;
-	}
-	if (async->buf_page_list) {
-		unsigned i;
-		for (i = 0; i < async->n_buf_pages; ++i) {
-			if (async->buf_page_list[i].virt_addr) {
-				clear_bit(PG_reserved,
-					&(virt_to_page(async->buf_page_list[i].
-							virt_addr)->flags));
-				if (s->async_dma_dir != DMA_NONE) {
-					dma_free_coherent(dev->hw_dev,
-							  PAGE_SIZE,
-							  async->
-							  buf_page_list
-							  [i].virt_addr,
-							  async->
-							  buf_page_list
-							  [i].dma_addr);
-				} else {
-					free_page((unsigned long)
-						  async->buf_page_list[i].
-						  virt_addr);
-				}
-			}
-		}
-		vfree(async->buf_page_list);
-		async->buf_page_list = NULL;
-		async->n_buf_pages = 0;
-	}
-	/*  allocate new buffer */
-	if (new_size) {
-		unsigned i = 0;
-		unsigned n_pages = new_size >> PAGE_SHIFT;
-		struct page **pages = NULL;
-
-		async->buf_page_list =
-		    vzalloc(sizeof(struct comedi_buf_page) * n_pages);
-		if (async->buf_page_list)
-			pages = vmalloc(sizeof(struct page *) * n_pages);
-
-		if (pages) {
-			for (i = 0; i < n_pages; i++) {
-				if (s->async_dma_dir != DMA_NONE) {
-					async->buf_page_list[i].virt_addr =
-					    dma_alloc_coherent(dev->hw_dev,
-							       PAGE_SIZE,
-							       &async->
-							       buf_page_list
-							       [i].dma_addr,
-							       GFP_KERNEL |
-							       __GFP_COMP);
-				} else {
-					async->buf_page_list[i].virt_addr =
-					    (void *)
-					    get_zeroed_page(GFP_KERNEL);
-				}
-				if (async->buf_page_list[i].virt_addr == NULL)
-					break;
-
-				set_bit(PG_reserved,
-					&(virt_to_page(async->buf_page_list[i].
-							virt_addr)->flags));
-				pages[i] = virt_to_page(async->buf_page_list[i].
-								virt_addr);
-			}
-		}
-		if (i == n_pages) {
-			async->prealloc_buf =
-#ifdef PAGE_KERNEL_NOCACHE
-			    vmap(pages, n_pages, VM_MAP, PAGE_KERNEL_NOCACHE);
-#else
-			    vmap(pages, n_pages, VM_MAP, PAGE_KERNEL);
-#endif
-		}
-		vfree(pages);
-
-		if (async->prealloc_buf == NULL) {
-			/* Some allocation failed above. */
-			if (async->buf_page_list) {
-				for (i = 0; i < n_pages; i++) {
-					if (async->buf_page_list[i].virt_addr ==
-					    NULL) {
-						break;
-					}
-					clear_bit(PG_reserved,
-						&(virt_to_page(async->
-							buf_page_list[i].
-							virt_addr)->flags));
-					if (s->async_dma_dir != DMA_NONE) {
-						dma_free_coherent(dev->hw_dev,
-								  PAGE_SIZE,
-								  async->
-								  buf_page_list
-								  [i].virt_addr,
-								  async->
-								  buf_page_list
-								  [i].dma_addr);
-					} else {
-						free_page((unsigned long)
-							  async->buf_page_list
-							  [i].virt_addr);
-					}
-				}
-				vfree(async->buf_page_list);
-				async->buf_page_list = NULL;
-			}
-			return -ENOMEM;
-		}
-		async->n_buf_pages = n_pages;
-	}
-	async->prealloc_bufsz = new_size;
-
-	return 0;
-}
+	if (dev->attached)
+		return -EBUSY;
 
-/* munging is applied to data by core as it passes between user
- * and kernel space */
-static unsigned int comedi_buf_munge(struct comedi_async *async,
-				     unsigned int num_bytes)
-{
-	struct comedi_subdevice *s = async->subdevice;
-	unsigned int count = 0;
-	const unsigned num_sample_bytes = bytes_per_sample(s);
-
-	if (s->munge == NULL || (async->cmd.flags & CMDF_RAWDATA)) {
-		async->munge_count += num_bytes;
-		BUG_ON((int)(async->munge_count - async->buf_write_count) > 0);
-		return num_bytes;
-	}
-	/* don't munge partial samples */
-	num_bytes -= num_bytes % num_sample_bytes;
-	while (count < num_bytes) {
-		int block_size;
-
-		block_size = num_bytes - count;
-		if (block_size < 0) {
-			dev_warn(s->device->class_dev,
-				 "%s: %s: bug! block_size is negative\n",
-				 __FILE__, __func__);
+	for (driv = comedi_drivers; driv; driv = driv->next) {
+		if (!try_module_get(driv->module))
+			continue;
+		if (driv->num_names) {
+			dev->board_ptr = comedi_recognize(driv, it->board_name);
+			if (dev->board_ptr)
+				break;
+		} else if (strcmp(driv->driver_name, it->board_name) == 0)
 			break;
-		}
-		if ((int)(async->munge_ptr + block_size -
-			  async->prealloc_bufsz) > 0)
-			block_size = async->prealloc_bufsz - async->munge_ptr;
-
-		s->munge(s->device, s, async->prealloc_buf + async->munge_ptr,
-			 block_size, async->munge_chan);
-
-		smp_wmb();	/* barrier insures data is munged in buffer
-				 * before munge_count is incremented */
-
-		async->munge_chan += block_size / num_sample_bytes;
-		async->munge_chan %= async->cmd.chanlist_len;
-		async->munge_count += block_size;
-		async->munge_ptr += block_size;
-		async->munge_ptr %= async->prealloc_bufsz;
-		count += block_size;
-	}
-	BUG_ON((int)(async->munge_count - async->buf_write_count) > 0);
-	return count;
-}
-
-unsigned int comedi_buf_write_n_available(struct comedi_async *async)
-{
-	unsigned int free_end;
-	unsigned int nbytes;
-
-	if (async == NULL)
-		return 0;
-
-	free_end = async->buf_read_count + async->prealloc_bufsz;
-	nbytes = free_end - async->buf_write_alloc_count;
-	nbytes -= nbytes % bytes_per_sample(async->subdevice);
-	/* barrier insures the read of buf_read_count in this
-	   query occurs before any following writes to the buffer which
-	   might be based on the return value from this query.
-	 */
-	smp_mb();
-	return nbytes;
-}
-
-/* allocates chunk for the writer from free buffer space */
-unsigned int comedi_buf_write_alloc(struct comedi_async *async,
-				    unsigned int nbytes)
-{
-	unsigned int free_end = async->buf_read_count + async->prealloc_bufsz;
-
-	if ((int)(async->buf_write_alloc_count + nbytes - free_end) > 0)
-		nbytes = free_end - async->buf_write_alloc_count;
-
-	async->buf_write_alloc_count += nbytes;
-	/* barrier insures the read of buf_read_count above occurs before
-	   we write data to the write-alloc'ed buffer space */
-	smp_mb();
-	return nbytes;
-}
-EXPORT_SYMBOL(comedi_buf_write_alloc);
-
-/* allocates nothing unless it can completely fulfill the request */
-unsigned int comedi_buf_write_alloc_strict(struct comedi_async *async,
-					   unsigned int nbytes)
-{
-	unsigned int free_end = async->buf_read_count + async->prealloc_bufsz;
-
-	if ((int)(async->buf_write_alloc_count + nbytes - free_end) > 0)
-		nbytes = 0;
-
-	async->buf_write_alloc_count += nbytes;
-	/* barrier insures the read of buf_read_count above occurs before
-	   we write data to the write-alloc'ed buffer space */
-	smp_mb();
-	return nbytes;
-}
-
-/* transfers a chunk from writer to filled buffer space */
-unsigned comedi_buf_write_free(struct comedi_async *async, unsigned int nbytes)
-{
-	if ((int)(async->buf_write_count + nbytes -
-		  async->buf_write_alloc_count) > 0) {
-		dev_info(async->subdevice->device->class_dev,
-			 "attempted to write-free more bytes than have been write-allocated.\n");
-		nbytes = async->buf_write_alloc_count - async->buf_write_count;
-	}
-	async->buf_write_count += nbytes;
-	async->buf_write_ptr += nbytes;
-	comedi_buf_munge(async, async->buf_write_count - async->munge_count);
-	if (async->buf_write_ptr >= async->prealloc_bufsz)
-		async->buf_write_ptr %= async->prealloc_bufsz;
-
-	return nbytes;
-}
-EXPORT_SYMBOL(comedi_buf_write_free);
-
-/* allocates a chunk for the reader from filled (and munged) buffer space */
-unsigned comedi_buf_read_alloc(struct comedi_async *async, unsigned nbytes)
-{
-	if ((int)(async->buf_read_alloc_count + nbytes - async->munge_count) >
-	    0) {
-		nbytes = async->munge_count - async->buf_read_alloc_count;
-	}
-	async->buf_read_alloc_count += nbytes;
-	/* barrier insures read of munge_count occurs before we actually read
-	   data out of buffer */
-	smp_rmb();
-	return nbytes;
-}
-EXPORT_SYMBOL(comedi_buf_read_alloc);
-
-/* transfers control of a chunk from reader to free buffer space */
-unsigned comedi_buf_read_free(struct comedi_async *async, unsigned int nbytes)
-{
-	/* barrier insures data has been read out of
-	 * buffer before read count is incremented */
-	smp_mb();
-	if ((int)(async->buf_read_count + nbytes -
-		  async->buf_read_alloc_count) > 0) {
-		dev_info(async->subdevice->device->class_dev,
-			 "attempted to read-free more bytes than have been read-allocated.\n");
-		nbytes = async->buf_read_alloc_count - async->buf_read_count;
+		module_put(driv->module);
 	}
-	async->buf_read_count += nbytes;
-	async->buf_read_ptr += nbytes;
-	async->buf_read_ptr %= async->prealloc_bufsz;
-	return nbytes;
-}
-EXPORT_SYMBOL(comedi_buf_read_free);
-
-void comedi_buf_memcpy_to(struct comedi_async *async, unsigned int offset,
-			  const void *data, unsigned int num_bytes)
-{
-	unsigned int write_ptr = async->buf_write_ptr + offset;
-
-	if (write_ptr >= async->prealloc_bufsz)
-		write_ptr %= async->prealloc_bufsz;
-
-	while (num_bytes) {
-		unsigned int block_size;
-
-		if (write_ptr + num_bytes > async->prealloc_bufsz)
-			block_size = async->prealloc_bufsz - write_ptr;
-		else
-			block_size = num_bytes;
-
-		memcpy(async->prealloc_buf + write_ptr, data, block_size);
-
-		data += block_size;
-		num_bytes -= block_size;
-
-		write_ptr = 0;
+	if (driv == NULL) {
+		/*  recognize has failed if we get here */
+		/*  report valid board names before returning error */
+		for (driv = comedi_drivers; driv; driv = driv->next) {
+			if (!try_module_get(driv->module))
+				continue;
+			comedi_report_boards(driv);
+			module_put(driv->module);
+		}
+		return -EIO;
 	}
-}
-EXPORT_SYMBOL(comedi_buf_memcpy_to);
-
-void comedi_buf_memcpy_from(struct comedi_async *async, unsigned int offset,
-			    void *dest, unsigned int nbytes)
-{
-	void *src;
-	unsigned int read_ptr = async->buf_read_ptr + offset;
-
-	if (read_ptr >= async->prealloc_bufsz)
-		read_ptr %= async->prealloc_bufsz;
-
-	while (nbytes) {
-		unsigned int block_size;
-
-		src = async->prealloc_buf + read_ptr;
-
-		if (nbytes >= async->prealloc_bufsz - read_ptr)
-			block_size = async->prealloc_bufsz - read_ptr;
-		else
-			block_size = nbytes;
-
-		memcpy(dest, src, block_size);
-		nbytes -= block_size;
-		dest += block_size;
-		read_ptr = 0;
+	if (driv->attach == NULL) {
+		/* driver does not support manual configuration */
+		dev_warn(dev->class_dev,
+			 "driver '%s' does not support attach using comedi_config\n",
+			 driv->driver_name);
+		module_put(driv->module);
+		return -ENOSYS;
 	}
-}
-EXPORT_SYMBOL(comedi_buf_memcpy_from);
-
-unsigned int comedi_buf_read_n_available(struct comedi_async *async)
-{
-	unsigned num_bytes;
-
-	if (async == NULL)
-		return 0;
-	num_bytes = async->munge_count - async->buf_read_count;
-	/* barrier insures the read of munge_count in this
-	   query occurs before any following reads of the buffer which
-	   might be based on the return value from this query.
-	 */
-	smp_rmb();
-	return num_bytes;
-}
-EXPORT_SYMBOL(comedi_buf_read_n_available);
-
-int comedi_buf_get(struct comedi_async *async, short *x)
-{
-	unsigned int n = comedi_buf_read_n_available(async);
-
-	if (n < sizeof(short))
-		return 0;
-	comedi_buf_read_alloc(async, sizeof(short));
-	*x = *(short *)(async->prealloc_buf + async->buf_read_ptr);
-	comedi_buf_read_free(async, sizeof(short));
-	return 1;
-}
-EXPORT_SYMBOL(comedi_buf_get);
-
-int comedi_buf_put(struct comedi_async *async, short x)
-{
-	unsigned int n = comedi_buf_write_alloc_strict(async, sizeof(short));
-
-	if (n < sizeof(short)) {
-		async->events |= COMEDI_CB_ERROR;
-		return 0;
+	/* initialize dev->driver here so
+	 * comedi_error() can be called from attach */
+	dev->driver = driv;
+	ret = driv->attach(dev, it);
+	if (ret < 0) {
+		module_put(dev->driver->module);
+		__comedi_device_detach(dev);
+		return ret;
 	}
-	*(short *)(async->prealloc_buf + async->buf_write_ptr) = x;
-	comedi_buf_write_free(async, sizeof(short));
-	return 1;
-}
-EXPORT_SYMBOL(comedi_buf_put);
-
-void comedi_reset_async_buf(struct comedi_async *async)
-{
-	async->buf_write_alloc_count = 0;
-	async->buf_write_count = 0;
-	async->buf_read_alloc_count = 0;
-	async->buf_read_count = 0;
-
-	async->buf_write_ptr = 0;
-	async->buf_read_ptr = 0;
-
-	async->cur_chan = 0;
-	async->scan_progress = 0;
-	async->munge_chan = 0;
-	async->munge_count = 0;
-	async->munge_ptr = 0;
-
-	async->events = 0;
+	return comedi_device_postconfig(dev);
 }
 
 int comedi_auto_config(struct device *hardware_device,
 		       struct comedi_driver *driver, unsigned long context)
 {
 	int minor;
-	struct comedi_device_file_info *dev_file_info;
 	struct comedi_device *comedi_dev;
 	int ret;
 
-	if (!comedi_autoconfig)
-		return 0;
-
 	if (!driver->auto_attach) {
 		dev_warn(hardware_device,
 			 "BUG! comedi driver '%s' has no auto_attach handler\n",
@@ -852,8 +420,7 @@ int comedi_auto_config(struct device *hardware_device,
 	if (minor < 0)
 		return minor;
 
-	dev_file_info = comedi_get_device_file_info(minor);
-	comedi_dev = dev_file_info->device;
+	comedi_dev = comedi_dev_from_minor(minor);
 
 	mutex_lock(&comedi_dev->mutex);
 	if (comedi_dev->attached)
@@ -888,103 +455,53 @@ void comedi_auto_unconfig(struct device *hardware_device)
 	minor = comedi_find_board_minor(hardware_device);
 	if (minor < 0)
 		return;
-	BUG_ON(minor >= COMEDI_NUM_BOARD_MINORS);
 	comedi_free_board_minor(minor);
 }
 EXPORT_SYMBOL_GPL(comedi_auto_unconfig);
 
-/**
- * comedi_pci_enable() - Enable the PCI device and request the regions.
- * @pdev: pci_dev struct
- * @res_name: name for the requested reqource
- */
-int comedi_pci_enable(struct pci_dev *pdev, const char *res_name)
-{
-	int rc;
-
-	rc = pci_enable_device(pdev);
-	if (rc < 0)
-		return rc;
-
-	rc = pci_request_regions(pdev, res_name);
-	if (rc < 0)
-		pci_disable_device(pdev);
-
-	return rc;
-}
-EXPORT_SYMBOL_GPL(comedi_pci_enable);
-
-/**
- * comedi_pci_disable() - Release the regions and disable the PCI device.
- * @pdev: pci_dev struct
- *
- * This must be matched with a previous successful call to comedi_pci_enable().
- */
-void comedi_pci_disable(struct pci_dev *pdev)
-{
-	pci_release_regions(pdev);
-	pci_disable_device(pdev);
-}
-EXPORT_SYMBOL_GPL(comedi_pci_disable);
-
-int comedi_pci_driver_register(struct comedi_driver *comedi_driver,
-		struct pci_driver *pci_driver)
+int comedi_driver_register(struct comedi_driver *driver)
 {
-	int ret;
-
-	ret = comedi_driver_register(comedi_driver);
-	if (ret < 0)
-		return ret;
-
-	/* FIXME: Remove this test after auditing all comedi pci drivers */
-	if (!pci_driver->name)
-		pci_driver->name = comedi_driver->driver_name;
-
-	ret = pci_register_driver(pci_driver);
-	if (ret < 0) {
-		comedi_driver_unregister(comedi_driver);
-		return ret;
-	}
+	driver->next = comedi_drivers;
+	comedi_drivers = driver;
 
 	return 0;
 }
-EXPORT_SYMBOL_GPL(comedi_pci_driver_register);
+EXPORT_SYMBOL(comedi_driver_register);
 
-void comedi_pci_driver_unregister(struct comedi_driver *comedi_driver,
-		struct pci_driver *pci_driver)
+int comedi_driver_unregister(struct comedi_driver *driver)
 {
-	pci_unregister_driver(pci_driver);
-	comedi_driver_unregister(comedi_driver);
-}
-EXPORT_SYMBOL_GPL(comedi_pci_driver_unregister);
-
-#if IS_ENABLED(CONFIG_USB)
+	struct comedi_driver *prev;
+	int i;
 
-int comedi_usb_driver_register(struct comedi_driver *comedi_driver,
-		struct usb_driver *usb_driver)
-{
-	int ret;
+	/* check for devices using this driver */
+	for (i = 0; i < COMEDI_NUM_BOARD_MINORS; i++) {
+		struct comedi_device *dev = comedi_dev_from_minor(i);
 
-	ret = comedi_driver_register(comedi_driver);
-	if (ret < 0)
-		return ret;
+		if (!dev)
+			continue;
 
-	ret = usb_register(usb_driver);
-	if (ret < 0) {
-		comedi_driver_unregister(comedi_driver);
-		return ret;
+		mutex_lock(&dev->mutex);
+		if (dev->attached && dev->driver == driver) {
+			if (dev->use_count)
+				dev_warn(dev->class_dev,
+					 "BUG! detaching device with use_count=%d\n",
+					 dev->use_count);
+			comedi_device_detach(dev);
+		}
+		mutex_unlock(&dev->mutex);
 	}
 
-	return 0;
-}
-EXPORT_SYMBOL_GPL(comedi_usb_driver_register);
+	if (comedi_drivers == driver) {
+		comedi_drivers = driver->next;
+		return 0;
+	}
 
-void comedi_usb_driver_unregister(struct comedi_driver *comedi_driver,
-		struct usb_driver *usb_driver)
-{
-	usb_deregister(usb_driver);
-	comedi_driver_unregister(comedi_driver);
+	for (prev = comedi_drivers; prev->next; prev = prev->next) {
+		if (prev->next == driver) {
+			prev->next = driver->next;
+			return 0;
+		}
+	}
+	return -EINVAL;
 }
-EXPORT_SYMBOL_GPL(comedi_usb_driver_unregister);
-
-#endif
+EXPORT_SYMBOL(comedi_driver_unregister);