diff options
Diffstat (limited to '')
| -rw-r--r-- | drivers/media/usb/pvrusb2/pvrusb2-ioread.c | 495 |
1 files changed, 495 insertions, 0 deletions
diff --git a/drivers/media/usb/pvrusb2/pvrusb2-ioread.c b/drivers/media/usb/pvrusb2/pvrusb2-ioread.c new file mode 100644 index 000000000..602097bdc --- /dev/null +++ b/drivers/media/usb/pvrusb2/pvrusb2-ioread.c @@ -0,0 +1,495 @@ +/* + * + * + * 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. + * + */ + +#include "pvrusb2-ioread.h" +#include "pvrusb2-debug.h" +#include <linux/errno.h> +#include <linux/string.h> +#include <linux/mm.h> +#include <linux/slab.h> +#include <linux/mutex.h> +#include <linux/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 = NULL; + 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,NULL); + 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 = kzalloc(sizeof(*cp),GFP_KERNEL); + if (!cp) return NULL; + pvr2_trace(PVR2_TRACE_STRUCT,"pvr2_ioread_create id=%p",cp); + if (pvr2_ioread_init(cp) < 0) { + kfree(cp); + return NULL; + } + 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 = NULL; + } + 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 = NULL; + } + 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 = NULL; + cp->c_data_ptr = NULL; + 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)) != NULL) { + 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 = NULL; + cp->c_data_ptr = NULL; + 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); + if (pvr2_stream_get_buffer_count(cp->stream)) { + pvr2_stream_set_buffer_count(cp->stream,0); + } + cp->stream = NULL; + } + 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) { + mutex_unlock(&cp->mutex); + 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; +} + +static 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 = NULL; + cp->c_data_ptr = NULL; + 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; +} + +static 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; +} |