--- /dev/null
+/*
+ * comedi_buf.c
+ *
+ * COMEDI - Linux Control and Measurement Device Interface
+ * Copyright (C) 1997-2000 David A. Schleef <ds@schleef.org>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+
+#include "comedidev.h"
+#include "comedi_internal.h"
+
+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;
+}
+
+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;
+}
+
+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;
+}
+
+/* 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__);
+ 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;
+}
+
+/* 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);
+
+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);
+
+/* 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;
+ }
+ 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);
+
+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;
+ }
+ *(short *)(async->prealloc_buf + async->buf_write_ptr) = x;
+ comedi_buf_write_free(async, sizeof(short));
+ return 1;
+}
+EXPORT_SYMBOL(comedi_buf_put);
+
+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);
+
+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;
+ }
+}
+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;
+ }
+}
+EXPORT_SYMBOL(comedi_buf_memcpy_from);
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;
-}
-
-/* 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__);
- 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;
- }
- 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;
- }
-}
-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;
- }
-}
-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;
- }
- *(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;
-}
-
int comedi_auto_config(struct device *hardware_device,
struct comedi_driver *driver, unsigned long context)
{
projects / GitHub / exynos8895 / android_kernel_samsung_universal8895.git / commitdiff