1 files changed, 513 insertions, 0 deletions

diff --git a/drivers/media/video/pvrusb2/pvrusb2-ioread.c b/drivers/media/video/pvrusb2/pvrusb2-ioread.c
new file mode 100644
index 000000000000..49da062e3271
--- /dev/null
+++ b/drivers/media/video/pvrusb2/pvrusb2-ioread.c
@@ -0,0 +1,513 @@
+/*
+ *
+ *  $Id$
+ *
+ *  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 <linux/mutex.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];
+        char *sync_key_ptr;
+        unsigned int sync_key_len;
+        unsigned int sync_buf_offs;
+        unsigned int sync_state;
+        unsigned int sync_trashed_count;
+        int enabled;         // Streaming is on
+        int spigot_open;     // OK to pass data to client
+        int stream_running;  // Passing data to client now
+
+        /* State relevant to current buffer being read */
+        struct pvr2_buffer *c_buf;
+        char *c_data_ptr;
+        unsigned int c_data_len;
+        unsigned int c_data_offs;
+        struct mutex mutex;
+};
+
+static int pvr2_ioread_init(struct pvr2_ioread *cp)
+{
+        unsigned int idx;
+
+        cp->stream = 0;
+        mutex_init(&cp->mutex);
+
+        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);
+        if (cp->sync_key_ptr) {
+                kfree(cp->sync_key_ptr);
+                cp->sync_key_ptr = 0;
+        }
+        kfree(cp);
+}
+
+void pvr2_ioread_set_sync_key(struct pvr2_ioread *cp,
+                              const char *sync_key_ptr,
+                              unsigned int sync_key_len)
+{
+        if (!cp) return;
+
+        if (!sync_key_ptr) sync_key_len = 0;
+        if ((sync_key_len == cp->sync_key_len) &&
+            ((!sync_key_len) ||
+             (!memcmp(sync_key_ptr,cp->sync_key_ptr,sync_key_len)))) return;
+
+        if (sync_key_len != cp->sync_key_len) {
+                if (cp->sync_key_ptr) {
+                        kfree(cp->sync_key_ptr);
+                        cp->sync_key_ptr = 0;
+                }
+                cp->sync_key_len = 0;
+                if (sync_key_len) {
+                        cp->sync_key_ptr = kmalloc(sync_key_len,GFP_KERNEL);
+                        if (cp->sync_key_ptr) {
+                                cp->sync_key_len = sync_key_len;
+                        }
+                }
+        }
+        if (!cp->sync_key_len) return;
+        memcpy(cp->sync_key_ptr,sync_key_ptr,cp->sync_key_len);
+}
+
+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->c_buf = 0;
+        cp->c_data_ptr = 0;
+        cp->c_data_len = 0;
+        cp->c_data_offs = 0;
+        cp->enabled = 0;
+        cp->stream_running = 0;
+        cp->spigot_open = 0;
+        if (cp->sync_state) {
+                pvr2_trace(PVR2_TRACE_DATA_FLOW,
+                           "/*---TRACE_READ---*/ sync_state <== 0");
+                cp->sync_state = 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);
+        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->c_buf = 0;
+        cp->c_data_ptr = 0;
+        cp->c_data_len = 0;
+        cp->c_data_offs = 0;
+        cp->stream_running = 0;
+        if (cp->sync_key_len) {
+                pvr2_trace(PVR2_TRACE_DATA_FLOW,
+                           "/*---TRACE_READ---*/ sync_state <== 1");
+                cp->sync_state = 1;
+                cp->sync_trashed_count = 0;
+                cp->sync_buf_offs = 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;
+
+        mutex_lock(&cp->mutex); 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); mutex_unlock(&cp->mutex);
+
+        return 0;
+}
+
+int pvr2_ioread_set_enabled(struct pvr2_ioread *cp,int fl)
+{
+        int ret = 0;
+        if ((!fl) == (!(cp->enabled))) return ret;
+
+        mutex_lock(&cp->mutex); do {
+                if (fl) {
+                        ret = pvr2_ioread_start(cp);
+                } else {
+                        pvr2_ioread_stop(cp);
+                }
+        } while (0); mutex_unlock(&cp->mutex);
+        return ret;
+}
+
+int pvr2_ioread_get_enabled(struct pvr2_ioread *cp)
+{
+        return cp->enabled != 0;
+}
+
+int pvr2_ioread_get_buffer(struct pvr2_ioread *cp)
+{
+        int stat;
+
+        while (cp->c_data_len <= cp->c_data_offs) {
+                if (cp->c_buf) {
+                        // Flush out current buffer first.
+                        stat = pvr2_buffer_queue(cp->c_buf);
+                        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);
+                                return 0;
+                        }
+                        cp->c_buf = 0;
+                        cp->c_data_ptr = 0;
+                        cp->c_data_len = 0;
+                        cp->c_data_offs = 0;
+                }
+                // Now get a freshly filled buffer.
+                cp->c_buf = pvr2_stream_get_ready_buffer(cp->stream);
+                if (!cp->c_buf) break; // Nothing ready; done.
+                cp->c_data_len = pvr2_buffer_get_count(cp->c_buf);
+                if (!cp->c_data_len) {
+                        // Nothing transferred.  Was there an error?
+                        stat = pvr2_buffer_get_status(cp->c_buf);
+                        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);
+                                // Give up.
+                                return 0;
+                        }
+                        // Start over...
+                        continue;
+                }
+                cp->c_data_offs = 0;
+                cp->c_data_ptr = cp->buffer_storage[
+                        pvr2_buffer_get_id(cp->c_buf)];
+        }
+        return !0;
+}
+
+void pvr2_ioread_filter(struct pvr2_ioread *cp)
+{
+        unsigned int idx;
+        if (!cp->enabled) return;
+        if (cp->sync_state != 1) return;
+
+        // Search the stream for our synchronization key.  This is made
+        // complicated by the fact that in order to be honest with
+        // ourselves here we must search across buffer boundaries...
+        mutex_lock(&cp->mutex); while (1) {
+                // Ensure we have a buffer
+                if (!pvr2_ioread_get_buffer(cp)) break;
+                if (!cp->c_data_len) break;
+
+                // Now walk the buffer contents until we match the key or
+                // run out of buffer data.
+                for (idx = cp->c_data_offs; idx < cp->c_data_len; idx++) {
+                        if (cp->sync_buf_offs >= cp->sync_key_len) break;
+                        if (cp->c_data_ptr[idx] ==
+                            cp->sync_key_ptr[cp->sync_buf_offs]) {
+                                // Found the next key byte
+                                (cp->sync_buf_offs)++;
+                        } else {
+                                // Whoops, mismatched.  Start key over...
+                                cp->sync_buf_offs = 0;
+                        }
+                }
+
+                // Consume what we've walked through
+                cp->c_data_offs += idx;
+                cp->sync_trashed_count += idx;
+
+                // If we've found the key, then update state and get out.
+                if (cp->sync_buf_offs >= cp->sync_key_len) {
+                        cp->sync_trashed_count -= cp->sync_key_len;
+                        pvr2_trace(PVR2_TRACE_DATA_FLOW,
+                                   "/*---TRACE_READ---*/"
+                                   " sync_state <== 2 (skipped %u bytes)",
+                                   cp->sync_trashed_count);
+                        cp->sync_state = 2;
+                        cp->sync_buf_offs = 0;
+                        break;
+                }
+
+                if (cp->c_data_offs < cp->c_data_len) {
+                        // Sanity check - should NEVER get here
+                        pvr2_trace(PVR2_TRACE_ERROR_LEGS,
+                                   "ERROR: pvr2_ioread filter sync problem"
+                                   " len=%u offs=%u",
+                                   cp->c_data_len,cp->c_data_offs);
+                        // Get out so we don't get stuck in an infinite
+                        // loop.
+                        break;
+                }
+
+                continue; // (for clarity)
+        } mutex_unlock(&cp->mutex);
+}
+
+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;
+        }
+
+        if (cp->sync_state == 1) {
+                pvr2_ioread_filter(cp);
+                if (cp->sync_state == 1) return -EAGAIN;
+        }
+
+        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;
+        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;
+
+        mutex_lock(&cp->mutex); do {
+
+                // Suck data out of the buffers and copy to the user
+                copied_cnt = 0;
+                if (!buf) cnt = 0;
+                while (1) {
+                        if (!pvr2_ioread_get_buffer(cp)) {
+                                ret = -EIO;
+                                break;
+                        }
+
+                        if (!cnt) break;
+
+                        if (cp->sync_state == 2) {
+                                // We're repeating the sync key data into
+                                // the stream.
+                                src = cp->sync_key_ptr + cp->sync_buf_offs;
+                                bcnt = cp->sync_key_len - cp->sync_buf_offs;
+                        } else {
+                                // Normal buffer copy
+                                src = cp->c_data_ptr + cp->c_data_offs;
+                                bcnt = cp->c_data_len - cp->c_data_offs;
+                        }
+
+                        if (!bcnt) break;
+
+                        // Don't run past user's buffer
+                        if (bcnt > cnt) bcnt = cnt;
+
+                        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->sync_state == 2) {
+                                // Update offset inside sync key that we're
+                                // repeating back out.
+                                cp->sync_buf_offs += bcnt;
+                                if (cp->sync_buf_offs >= cp->sync_key_len) {
+                                        // Consumed entire key; switch mode
+                                        // to normal.
+                                        pvr2_trace(PVR2_TRACE_DATA_FLOW,
+                                                   "/*---TRACE_READ---*/"
+                                                   " sync_state <== 0");
+                                        cp->sync_state = 0;
+                                }
+                        } else {
+                                // Update buffer offset.
+                                cp->c_data_offs += bcnt;
+                        }
+                }
+
+        } while (0); mutex_unlock(&cp->mutex);
+
+        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: ***
+  */