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Diffstat (limited to 'v4l_experimental/pvrusb2/pvrusb2-ioread.c')
-rw-r--r--v4l_experimental/pvrusb2/pvrusb2-ioread.c357
1 files changed, 357 insertions, 0 deletions
diff --git a/v4l_experimental/pvrusb2/pvrusb2-ioread.c b/v4l_experimental/pvrusb2/pvrusb2-ioread.c
new file mode 100644
index 000000000..5517e545c
--- /dev/null
+++ b/v4l_experimental/pvrusb2/pvrusb2-ioread.c
@@ -0,0 +1,357 @@
+/*
+ *
+ * $Id: pvrusb2-ioread.c,v 1.1 2005/11/14 13:31:24 mchehab Exp $
+ *
+ * Copyright (C) 2005 Mike Isely <isely@pobox.com>
+ *
+ * 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
+ *
+ * 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., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ *
+ */
+
+#include "pvrusb2-ioread.h"
+#include "pvrusb2-debug.h"
+#include <linux/errno.h>
+#include <linux/string.h>
+#include <linux/slab.h>
+#include <asm/semaphore.h>
+#include <asm/uaccess.h>
+
+#define BUFFER_COUNT 32
+#define BUFFER_SIZE PAGE_ALIGN(0x4000)
+
+struct pvr2_ioread {
+ struct pvr2_stream *stream;
+ char *buffer_storage[BUFFER_COUNT];
+ int resid_offs;
+ int enabled;
+ int stream_running;
+ int spigot_open;
+ struct semaphore sem;
+};
+
+static int pvr2_ioread_init(struct pvr2_ioread *cp)
+{
+ unsigned int idx;
+
+ cp->stream = 0;
+ init_MUTEX(&cp->sem);
+
+ for (idx = 0; idx < BUFFER_COUNT; idx++) {
+ cp->buffer_storage[idx] = kmalloc(BUFFER_SIZE,GFP_KERNEL);
+ if (!(cp->buffer_storage[idx])) break;
+ }
+
+ if (idx < BUFFER_COUNT) {
+ // An allocation appears to have failed
+ for (idx = 0; idx < BUFFER_COUNT; idx++) {
+ if (!(cp->buffer_storage[idx])) continue;
+ kfree(cp->buffer_storage[idx]);
+ }
+ return -ENOMEM;
+ }
+ return 0;
+}
+
+static void pvr2_ioread_done(struct pvr2_ioread *cp)
+{
+ unsigned int idx;
+
+ pvr2_ioread_setup(cp,0);
+ for (idx = 0; idx < BUFFER_COUNT; idx++) {
+ if (!(cp->buffer_storage[idx])) continue;
+ kfree(cp->buffer_storage[idx]);
+ }
+}
+
+struct pvr2_ioread *pvr2_ioread_create(void)
+{
+ struct pvr2_ioread *cp;
+ cp = kmalloc(sizeof(*cp),GFP_KERNEL);
+ if (!cp) return 0;
+ pvr2_trace(PVR2_TRACE_STRUCT,"pvr2_ioread_create id=%p",cp);
+ memset(cp,0,sizeof(*cp));
+ if (pvr2_ioread_init(cp) < 0) {
+ kfree(cp);
+ return 0;
+ }
+ return cp;
+}
+
+void pvr2_ioread_destroy(struct pvr2_ioread *cp)
+{
+ if (!cp) return;
+ pvr2_ioread_done(cp);
+ pvr2_trace(PVR2_TRACE_STRUCT,"pvr2_ioread_destroy id=%p",cp);
+ kfree(cp);
+}
+
+static void pvr2_ioread_stop(struct pvr2_ioread *cp)
+{
+ if (!(cp->enabled)) return;
+ pvr2_trace(PVR2_TRACE_START_STOP,
+ "/*---TRACE_READ---*/ pvr2_ioread_stop id=%p",cp);
+ pvr2_stream_kill(cp->stream);
+ cp->resid_offs = 0;
+ cp->enabled = 0;
+ cp->stream_running = 0;
+ cp->spigot_open = 0;
+}
+
+static int pvr2_ioread_start(struct pvr2_ioread *cp)
+{
+ int stat;
+ struct pvr2_buffer *bp;
+ if (cp->enabled) return 0;
+ if (!(cp->stream)) return 0;
+ pvr2_trace(PVR2_TRACE_START_STOP,
+ "/*---TRACE_READ---*/ pvr2_ioread_start id=%p",cp);
+ cp->resid_offs = 0;
+ while ((bp = pvr2_stream_get_idle_buffer(cp->stream)) != 0) {
+ stat = pvr2_buffer_queue(bp);
+ if (stat < 0) {
+ pvr2_trace(PVR2_TRACE_DATA_FLOW,
+ "/*---TRACE_READ---*/"
+ " pvr2_ioread_start id=%p"
+ " error=%d",
+ cp,stat);
+ pvr2_ioread_stop(cp);
+ return stat;
+ }
+ }
+ cp->enabled = !0;
+ cp->stream_running = 0;
+ cp->spigot_open = 0;
+ return 0;
+}
+
+struct pvr2_stream *pvr2_ioread_get_stream(struct pvr2_ioread *cp)
+{
+ return cp->stream;
+}
+
+int pvr2_ioread_setup(struct pvr2_ioread *cp,struct pvr2_stream *sp)
+{
+ int ret;
+ unsigned int idx;
+ struct pvr2_buffer *bp;
+
+ down(&cp->sem); do {
+ if (cp->stream) {
+ pvr2_trace(PVR2_TRACE_START_STOP,
+ "/*---TRACE_READ---*/"
+ " pvr2_ioread_setup (tear-down) id=%p",cp);
+ pvr2_ioread_stop(cp);
+ pvr2_stream_kill(cp->stream);
+ pvr2_stream_set_buffer_count(cp->stream,0);
+ cp->stream = 0;
+ }
+ if (sp) {
+ pvr2_trace(PVR2_TRACE_START_STOP,
+ "/*---TRACE_READ---*/"
+ " pvr2_ioread_setup (setup) id=%p",cp);
+ pvr2_stream_kill(sp);
+ ret = pvr2_stream_set_buffer_count(sp,BUFFER_COUNT);
+ if (ret < 0) return ret;
+ for (idx = 0; idx < BUFFER_COUNT; idx++) {
+ bp = pvr2_stream_get_buffer(sp,idx);
+ pvr2_buffer_set_buffer(bp,
+ cp->buffer_storage[idx],
+ BUFFER_SIZE);
+ }
+ cp->stream = sp;
+ }
+ } while (0); up(&cp->sem);
+
+ return 0;
+}
+
+int pvr2_ioread_set_enabled(struct pvr2_ioread *cp,int fl)
+{
+ int ret = 0;
+ if ((!fl) == (!(cp->enabled))) return ret;
+
+ down(&cp->sem); do {
+ if (fl) {
+ ret = pvr2_ioread_start(cp);
+ } else {
+ pvr2_ioread_stop(cp);
+ }
+ } while (0); up(&cp->sem);
+ return ret;
+}
+
+int pvr2_ioread_get_enabled(struct pvr2_ioread *cp)
+{
+ return cp->enabled != 0;
+}
+
+int pvr2_ioread_avail(struct pvr2_ioread *cp)
+{
+ int ret;
+ if (!(cp->enabled)) {
+ // Stream is not enabled; so this is an I/O error
+ return -EIO;
+ }
+
+ ret = 0;
+ if (cp->stream_running) {
+ if (!pvr2_stream_get_ready_count(cp->stream)) {
+ // No data available at all right now.
+ ret = -EAGAIN;
+ }
+ } else {
+ if (pvr2_stream_get_ready_count(cp->stream) < BUFFER_COUNT/2) {
+ // Haven't buffered up enough yet; try again later
+ ret = -EAGAIN;
+ }
+ }
+
+ if ((!(cp->spigot_open)) != (!(ret == 0))) {
+ cp->spigot_open = (ret == 0);
+ pvr2_trace(PVR2_TRACE_DATA_FLOW,
+ "/*---TRACE_READ---*/ data is %s",
+ cp->spigot_open ? "available" : "pending");
+ }
+
+ return ret;
+}
+
+int pvr2_ioread_read(struct pvr2_ioread *cp,void __user *buf,unsigned int cnt)
+{
+ unsigned int copied_cnt;
+ unsigned int bcnt;
+ const char *src;
+ int stat;
+ struct pvr2_buffer *bp;
+ int ret = 0;
+ unsigned int req_cnt = cnt;
+
+ if (!cnt) {
+ pvr2_trace(PVR2_TRACE_TRAP,
+ "/*---TRACE_READ---*/ pvr2_ioread_read id=%p"
+ " ZERO Request? Returning zero.",cp);
+ return 0;
+ }
+
+ stat = pvr2_ioread_avail(cp);
+ if (stat < 0) return stat;
+
+ cp->stream_running = !0;
+
+ down(&cp->sem); do {
+
+ // Suck data out of the buffers and copy to the user
+ copied_cnt = 0;
+ if (!buf) cnt = 0;
+ while (cnt) {
+ bp = pvr2_stream_get_ready_buffer(cp->stream);
+ if (!bp) break; // Nothing ready; done
+
+ bcnt = pvr2_buffer_get_count(bp);
+ if (!bcnt) {
+ // Nothing transferred. Was there an
+ // error?
+ stat = pvr2_buffer_get_status(bp);
+ if (stat < 0) {
+ // Streaming error...
+ pvr2_trace(PVR2_TRACE_DATA_FLOW,
+ "/*---TRACE_READ---*/"
+ " pvr2_ioread_read id=%p"
+ " buffer_error=%d",
+ cp,stat);
+ pvr2_ioread_stop(cp);
+ ret = -EIO;
+ break;
+ }
+ src = 0;
+ } else {
+ // Calculate buffer offset and count
+ src = cp->buffer_storage[
+ pvr2_buffer_get_id(bp)];
+ if (cp->resid_offs > bcnt) {
+ cp->resid_offs = bcnt;
+ }
+ src += cp->resid_offs;
+ bcnt -= cp->resid_offs;
+ }
+ if (bcnt > cnt) {
+ // Can't read the entire buffer this time
+ // so remember how far in we're going to
+ // get so we can resume it later
+ bcnt = cnt;
+ cp->resid_offs += bcnt;
+ } else {
+ // We will be able to get the whole thing,
+ // so clear the residual offset
+ cp->resid_offs = 0;
+ }
+ if (bcnt) {
+ if (copy_to_user(buf,src,bcnt)) {
+ // User supplied a bad pointer?
+ // Give up - this *will* cause data
+ // to be lost.
+ ret = -EFAULT;
+ break;
+ }
+ cnt -= bcnt;
+ buf += bcnt;
+ copied_cnt += bcnt;
+ }
+ if (cp->resid_offs) break; // If there's a residual
+ // offset, get out
+ // Queue the buffer now that we've consumed it.
+ stat = pvr2_buffer_queue(bp);
+ if (stat < 0) {
+ // Streaming error...
+ pvr2_trace(PVR2_TRACE_DATA_FLOW,
+ "/*---TRACE_READ---*/"
+ " pvr2_ioread_read id=%p"
+ " queue_error=%d",
+ cp,stat);
+ pvr2_ioread_stop(cp);
+ ret = stat;
+ break;
+ }
+ }
+
+ } while (0); up(&cp->sem);
+
+ if (!ret) {
+ if (copied_cnt) {
+ // If anything was copied, return that count
+ ret = copied_cnt;
+ } else {
+ // Nothing copied; suggest to caller that another
+ // attempt should be tried again later
+ ret = -EAGAIN;
+ }
+ }
+
+ pvr2_trace(PVR2_TRACE_DATA_FLOW,
+ "/*---TRACE_READ---*/ pvr2_ioread_read"
+ " id=%p request=%d result=%d",
+ cp,req_cnt,ret);
+ return ret;
+}
+
+
+/*
+ Stuff for Emacs to see, in order to encourage consistent editing style:
+ *** Local Variables: ***
+ *** mode: c ***
+ *** fill-column: 75 ***
+ *** tab-width: 8 ***
+ *** c-basic-offset: 8 ***
+ *** End: ***
+ */
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