[linux-2.6-block.git] / drivers / media / video / pvrusb2 / pvrusb2-ioread.c

/*
 *
 *  $Id$
 *
 *  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 = 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 = kmalloc(sizeof(*cp),GFP_KERNEL);
	if (!cp) return NULL;
	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 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)) != 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 = 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) 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;
}


/*
  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: ***
  */
Commit	Line	Data
d855497e MI	1	/*
	2	*
	3	* $Id$
	4	*
	5	* Copyright (C) 2005 Mike Isely <isely@pobox.com>
	6	*
	7	* This program is free software; you can redistribute it and/or modify
	8	* it under the terms of the GNU General Public License as published by
	9	* the Free Software Foundation; either version 2 of the License
	10	*
	11	* This program is distributed in the hope that it will be useful,
	12	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	13	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	14	* GNU General Public License for more details.
	15	*
	16	* You should have received a copy of the GNU General Public License
	17	* along with this program; if not, write to the Free Software
	18	* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
	19	*
	20	*/
	21
	22	#include "pvrusb2-ioread.h"
	23	#include "pvrusb2-debug.h"
	24	#include <linux/errno.h>
	25	#include <linux/string.h>
	26	#include <linux/slab.h>
	27	#include <linux/mutex.h>
	28	#include <asm/uaccess.h>
	29
	30	#define BUFFER_COUNT 32
	31	#define BUFFER_SIZE PAGE_ALIGN(0x4000)
	32
	33	struct pvr2_ioread {
	34	struct pvr2_stream *stream;
	35	char *buffer_storage[BUFFER_COUNT];
	36	char *sync_key_ptr;
	37	unsigned int sync_key_len;
	38	unsigned int sync_buf_offs;
	39	unsigned int sync_state;
	40	unsigned int sync_trashed_count;
	41	int enabled; // Streaming is on
	42	int spigot_open; // OK to pass data to client
	43	int stream_running; // Passing data to client now
	44
	45	/* State relevant to current buffer being read */
	46	struct pvr2_buffer *c_buf;
	47	char *c_data_ptr;
	48	unsigned int c_data_len;
	49	unsigned int c_data_offs;
	50	struct mutex mutex;
	51	};
	52
	53	static int pvr2_ioread_init(struct pvr2_ioread *cp)
	54	{
	55	unsigned int idx;
	56
a0fd1cb1	57	cp->stream = NULL;
d855497e MI	58	mutex_init(&cp->mutex);
	59
	60	for (idx = 0; idx < BUFFER_COUNT; idx++) {
	61	cp->buffer_storage[idx] = kmalloc(BUFFER_SIZE,GFP_KERNEL);
	62	if (!(cp->buffer_storage[idx])) break;
	63	}
	64
	65	if (idx < BUFFER_COUNT) {
	66	// An allocation appears to have failed
	67	for (idx = 0; idx < BUFFER_COUNT; idx++) {
	68	if (!(cp->buffer_storage[idx])) continue;
	69	kfree(cp->buffer_storage[idx]);
	70	}
	71	return -ENOMEM;
	72	}
	73	return 0;
	74	}
	75
	76	static void pvr2_ioread_done(struct pvr2_ioread *cp)
	77	{
	78	unsigned int idx;
	79
a0fd1cb1	80	pvr2_ioread_setup(cp,NULL);
d855497e MI	81	for (idx = 0; idx < BUFFER_COUNT; idx++) {
	82	if (!(cp->buffer_storage[idx])) continue;
	83	kfree(cp->buffer_storage[idx]);
	84	}
	85	}
	86
	87	struct pvr2_ioread *pvr2_ioread_create(void)
	88	{
	89	struct pvr2_ioread *cp;
	90	cp = kmalloc(sizeof(*cp),GFP_KERNEL);
a0fd1cb1	91	if (!cp) return NULL;
d855497e MI	92	pvr2_trace(PVR2_TRACE_STRUCT,"pvr2_ioread_create id=%p",cp);
	93	memset(cp,0,sizeof(*cp));
	94	if (pvr2_ioread_init(cp) < 0) {
	95	kfree(cp);
a0fd1cb1	96	return NULL;
d855497e MI	97	}
	98	return cp;
	99	}
	100
	101	void pvr2_ioread_destroy(struct pvr2_ioread *cp)
	102	{
	103	if (!cp) return;
	104	pvr2_ioread_done(cp);
	105	pvr2_trace(PVR2_TRACE_STRUCT,"pvr2_ioread_destroy id=%p",cp);
	106	if (cp->sync_key_ptr) {
	107	kfree(cp->sync_key_ptr);
a0fd1cb1	108	cp->sync_key_ptr = NULL;
d855497e MI	109	}
	110	kfree(cp);
	111	}
	112
	113	void pvr2_ioread_set_sync_key(struct pvr2_ioread *cp,
	114	const char *sync_key_ptr,
	115	unsigned int sync_key_len)
	116	{
	117	if (!cp) return;
	118
	119	if (!sync_key_ptr) sync_key_len = 0;
	120	if ((sync_key_len == cp->sync_key_len) &&
	121	((!sync_key_len) \|\|
	122	(!memcmp(sync_key_ptr,cp->sync_key_ptr,sync_key_len)))) return;
	123
	124	if (sync_key_len != cp->sync_key_len) {
	125	if (cp->sync_key_ptr) {
	126	kfree(cp->sync_key_ptr);
a0fd1cb1	127	cp->sync_key_ptr = NULL;
d855497e MI	128	}
	129	cp->sync_key_len = 0;
	130	if (sync_key_len) {
	131	cp->sync_key_ptr = kmalloc(sync_key_len,GFP_KERNEL);
	132	if (cp->sync_key_ptr) {
	133	cp->sync_key_len = sync_key_len;
	134	}
	135	}
	136	}
	137	if (!cp->sync_key_len) return;
	138	memcpy(cp->sync_key_ptr,sync_key_ptr,cp->sync_key_len);
	139	}
	140
	141	static void pvr2_ioread_stop(struct pvr2_ioread *cp)
	142	{
	143	if (!(cp->enabled)) return;
	144	pvr2_trace(PVR2_TRACE_START_STOP,
	145	"/---TRACE_READ---/ pvr2_ioread_stop id=%p",cp);
	146	pvr2_stream_kill(cp->stream);
a0fd1cb1 MI	147	cp->c_buf = NULL;
a0fd1cb1 MI	148	cp->c_data_ptr = NULL;
d855497e MI	149	cp->c_data_len = 0;
	150	cp->c_data_offs = 0;
	151	cp->enabled = 0;
	152	cp->stream_running = 0;
	153	cp->spigot_open = 0;
	154	if (cp->sync_state) {
	155	pvr2_trace(PVR2_TRACE_DATA_FLOW,
	156	"/---TRACE_READ---/ sync_state <== 0");
	157	cp->sync_state = 0;
	158	}
	159	}
	160
	161	static int pvr2_ioread_start(struct pvr2_ioread *cp)
	162	{
	163	int stat;
	164	struct pvr2_buffer *bp;
	165	if (cp->enabled) return 0;
	166	if (!(cp->stream)) return 0;
	167	pvr2_trace(PVR2_TRACE_START_STOP,
	168	"/---TRACE_READ---/ pvr2_ioread_start id=%p",cp);
	169	while ((bp = pvr2_stream_get_idle_buffer(cp->stream)) != 0) {
	170	stat = pvr2_buffer_queue(bp);
	171	if (stat < 0) {
	172	pvr2_trace(PVR2_TRACE_DATA_FLOW,
	173	"/---TRACE_READ---/"
	174	" pvr2_ioread_start id=%p"
	175	" error=%d",
	176	cp,stat);
	177	pvr2_ioread_stop(cp);
	178	return stat;
	179	}
	180	}
	181	cp->enabled = !0;
a0fd1cb1 MI	182	cp->c_buf = NULL;
a0fd1cb1 MI	183	cp->c_data_ptr = NULL;
d855497e MI	184	cp->c_data_len = 0;
	185	cp->c_data_offs = 0;
	186	cp->stream_running = 0;
	187	if (cp->sync_key_len) {
	188	pvr2_trace(PVR2_TRACE_DATA_FLOW,
	189	"/---TRACE_READ---/ sync_state <== 1");
	190	cp->sync_state = 1;
	191	cp->sync_trashed_count = 0;
	192	cp->sync_buf_offs = 0;
	193	}
	194	cp->spigot_open = 0;
	195	return 0;
	196	}
	197
	198	struct pvr2_stream pvr2_ioread_get_stream(struct pvr2_ioread cp)
	199	{
	200	return cp->stream;
	201	}
	202
	203	int pvr2_ioread_setup(struct pvr2_ioread cp,struct pvr2_stream sp)
	204	{
	205	int ret;
	206	unsigned int idx;
	207	struct pvr2_buffer *bp;
	208
	209	mutex_lock(&cp->mutex); do {
	210	if (cp->stream) {
	211	pvr2_trace(PVR2_TRACE_START_STOP,
	212	"/---TRACE_READ---/"
	213	" pvr2_ioread_setup (tear-down) id=%p",cp);
	214	pvr2_ioread_stop(cp);
	215	pvr2_stream_kill(cp->stream);
e61b6fc5 MI	216	if (pvr2_stream_get_buffer_count(cp->stream)) {
	217	pvr2_stream_set_buffer_count(cp->stream,0);
	218	}
a0fd1cb1	219	cp->stream = NULL;
d855497e MI	220	}
	221	if (sp) {
	222	pvr2_trace(PVR2_TRACE_START_STOP,
	223	"/---TRACE_READ---/"
	224	" pvr2_ioread_setup (setup) id=%p",cp);
	225	pvr2_stream_kill(sp);
	226	ret = pvr2_stream_set_buffer_count(sp,BUFFER_COUNT);
	227	if (ret < 0) return ret;
	228	for (idx = 0; idx < BUFFER_COUNT; idx++) {
	229	bp = pvr2_stream_get_buffer(sp,idx);
	230	pvr2_buffer_set_buffer(bp,
	231	cp->buffer_storage[idx],
	232	BUFFER_SIZE);
	233	}
	234	cp->stream = sp;
	235	}
	236	} while (0); mutex_unlock(&cp->mutex);
	237
	238	return 0;
	239	}
	240
	241	int pvr2_ioread_set_enabled(struct pvr2_ioread *cp,int fl)
	242	{
	243	int ret = 0;
	244	if ((!fl) == (!(cp->enabled))) return ret;
	245
	246	mutex_lock(&cp->mutex); do {
	247	if (fl) {
	248	ret = pvr2_ioread_start(cp);
	249	} else {
	250	pvr2_ioread_stop(cp);
	251	}
	252	} while (0); mutex_unlock(&cp->mutex);
	253	return ret;
	254	}
	255
07e337ee	256	static int pvr2_ioread_get_buffer(struct pvr2_ioread *cp)
d855497e MI	257	{
	258	int stat;
	259
	260	while (cp->c_data_len <= cp->c_data_offs) {
	261	if (cp->c_buf) {
	262	// Flush out current buffer first.
	263	stat = pvr2_buffer_queue(cp->c_buf);
	264	if (stat < 0) {
	265	// Streaming error...
	266	pvr2_trace(PVR2_TRACE_DATA_FLOW,
	267	"/---TRACE_READ---/"
	268	" pvr2_ioread_read id=%p"
	269	" queue_error=%d",
	270	cp,stat);
	271	pvr2_ioread_stop(cp);
	272	return 0;
	273	}
a0fd1cb1 MI	274	cp->c_buf = NULL;
a0fd1cb1 MI	275	cp->c_data_ptr = NULL;
d855497e MI	276	cp->c_data_len = 0;
	277	cp->c_data_offs = 0;
	278	}
	279	// Now get a freshly filled buffer.
	280	cp->c_buf = pvr2_stream_get_ready_buffer(cp->stream);
	281	if (!cp->c_buf) break; // Nothing ready; done.
	282	cp->c_data_len = pvr2_buffer_get_count(cp->c_buf);
	283	if (!cp->c_data_len) {
	284	// Nothing transferred. Was there an error?
	285	stat = pvr2_buffer_get_status(cp->c_buf);
	286	if (stat < 0) {
	287	// Streaming error...
	288	pvr2_trace(PVR2_TRACE_DATA_FLOW,
	289	"/---TRACE_READ---/"
	290	" pvr2_ioread_read id=%p"
	291	" buffer_error=%d",
	292	cp,stat);
	293	pvr2_ioread_stop(cp);
	294	// Give up.
	295	return 0;
	296	}
	297	// Start over...
	298	continue;
	299	}
	300	cp->c_data_offs = 0;
	301	cp->c_data_ptr = cp->buffer_storage[
	302	pvr2_buffer_get_id(cp->c_buf)];
	303	}
	304	return !0;
	305	}
	306
07e337ee	307	static void pvr2_ioread_filter(struct pvr2_ioread *cp)
d855497e MI	308	{
	309	unsigned int idx;
	310	if (!cp->enabled) return;
	311	if (cp->sync_state != 1) return;
	312
	313	// Search the stream for our synchronization key. This is made
	314	// complicated by the fact that in order to be honest with
	315	// ourselves here we must search across buffer boundaries...
	316	mutex_lock(&cp->mutex); while (1) {
	317	// Ensure we have a buffer
	318	if (!pvr2_ioread_get_buffer(cp)) break;
	319	if (!cp->c_data_len) break;
	320
	321	// Now walk the buffer contents until we match the key or
	322	// run out of buffer data.
	323	for (idx = cp->c_data_offs; idx < cp->c_data_len; idx++) {
	324	if (cp->sync_buf_offs >= cp->sync_key_len) break;
	325	if (cp->c_data_ptr[idx] ==
	326	cp->sync_key_ptr[cp->sync_buf_offs]) {
	327	// Found the next key byte
	328	(cp->sync_buf_offs)++;
	329	} else {
	330	// Whoops, mismatched. Start key over...
	331	cp->sync_buf_offs = 0;
	332	}
	333	}
	334
	335	// Consume what we've walked through
	336	cp->c_data_offs += idx;
	337	cp->sync_trashed_count += idx;
	338
	339	// If we've found the key, then update state and get out.
	340	if (cp->sync_buf_offs >= cp->sync_key_len) {
	341	cp->sync_trashed_count -= cp->sync_key_len;
	342	pvr2_trace(PVR2_TRACE_DATA_FLOW,
	343	"/---TRACE_READ---/"
	344	" sync_state <== 2 (skipped %u bytes)",
	345	cp->sync_trashed_count);
	346	cp->sync_state = 2;
	347	cp->sync_buf_offs = 0;
	348	break;
	349	}
	350
	351	if (cp->c_data_offs < cp->c_data_len) {
	352	// Sanity check - should NEVER get here
	353	pvr2_trace(PVR2_TRACE_ERROR_LEGS,
	354	"ERROR: pvr2_ioread filter sync problem"
	355	" len=%u offs=%u",
	356	cp->c_data_len,cp->c_data_offs);
	357	// Get out so we don't get stuck in an infinite
	358	// loop.
	359	break;
	360	}
	361
	362	continue; // (for clarity)
	363	} mutex_unlock(&cp->mutex);
	364	}
	365
	366	int pvr2_ioread_avail(struct pvr2_ioread *cp)
	367	{
	368	int ret;
	369	if (!(cp->enabled)) {
	370	// Stream is not enabled; so this is an I/O error
	371	return -EIO;
372	}
373
374	if (cp->sync_state == 1) {
375	pvr2_ioread_filter(cp);
376	if (cp->sync_state == 1) return -EAGAIN;
377	}
378
379	ret = 0;
380	if (cp->stream_running) {
381	if (!pvr2_stream_get_ready_count(cp->stream)) {
382	// No data available at all right now.
383	ret = -EAGAIN;
384	}
385	} else {
386	if (pvr2_stream_get_ready_count(cp->stream) < BUFFER_COUNT/2) {
387	// Haven't buffered up enough yet; try again later
388	ret = -EAGAIN;
389	}
390	}
391
392	if ((!(cp->spigot_open)) != (!(ret == 0))) {
393	cp->spigot_open = (ret == 0);
394	pvr2_trace(PVR2_TRACE_DATA_FLOW,
395	"/---TRACE_READ---/ data is %s",
396	cp->spigot_open ? "available" : "pending");
397	}
398
399	return ret;
400	}
401
402	int pvr2_ioread_read(struct pvr2_ioread cp,void __user buf,unsigned int cnt)
403	{
404	unsigned int copied_cnt;
405	unsigned int bcnt;
406	const char *src;
407	int stat;
408	int ret = 0;
409	unsigned int req_cnt = cnt;
410
411	if (!cnt) {
412	pvr2_trace(PVR2_TRACE_TRAP,
413	"/---TRACE_READ---/ pvr2_ioread_read id=%p"
414	" ZERO Request? Returning zero.",cp);
415	return 0;
416	}
417
418	stat = pvr2_ioread_avail(cp);
419	if (stat < 0) return stat;
420
421	cp->stream_running = !0;
422
423	mutex_lock(&cp->mutex); do {
424
425	// Suck data out of the buffers and copy to the user
426	copied_cnt = 0;
427	if (!buf) cnt = 0;
428	while (1) {
429	if (!pvr2_ioread_get_buffer(cp)) {
430	ret = -EIO;
431	break;
432	}
433
434	if (!cnt) break;
435
436	if (cp->sync_state == 2) {
437	// We're repeating the sync key data into
438	// the stream.
439	src = cp->sync_key_ptr + cp->sync_buf_offs;
440	bcnt = cp->sync_key_len - cp->sync_buf_offs;
441	} else {
442	// Normal buffer copy
443	src = cp->c_data_ptr + cp->c_data_offs;
444	bcnt = cp->c_data_len - cp->c_data_offs;
445	}
446
447	if (!bcnt) break;
448
449	// Don't run past user's buffer
450	if (bcnt > cnt) bcnt = cnt;
451
452	if (copy_to_user(buf,src,bcnt)) {
453	// User supplied a bad pointer?
454	// Give up - this will cause data
455	// to be lost.
456	ret = -EFAULT;
457	break;
458	}
459	cnt -= bcnt;
460	buf += bcnt;
461	copied_cnt += bcnt;
462
463	if (cp->sync_state == 2) {
464	// Update offset inside sync key that we're
465	// repeating back out.
466	cp->sync_buf_offs += bcnt;
467	if (cp->sync_buf_offs >= cp->sync_key_len) {
468	// Consumed entire key; switch mode
469	// to normal.
470	pvr2_trace(PVR2_TRACE_DATA_FLOW,
471	"/---TRACE_READ---/"
472	" sync_state <== 0");
473	cp->sync_state = 0;
474	}
475	} else {
476	// Update buffer offset.
477	cp->c_data_offs += bcnt;
478	}
479	}
480
481	} while (0); mutex_unlock(&cp->mutex);
482
483	if (!ret) {
484	if (copied_cnt) {
485	// If anything was copied, return that count
486	ret = copied_cnt;
487	} else {
488	// Nothing copied; suggest to caller that another
489	// attempt should be tried again later
490	ret = -EAGAIN;
491	}
492	}
493
494	pvr2_trace(PVR2_TRACE_DATA_FLOW,
495	"/---TRACE_READ---/ pvr2_ioread_read"
496	" id=%p request=%d result=%d",
497	cp,req_cnt,ret);
498	return ret;
499	}
500
501
502	/*
503	Stuff for Emacs to see, in order to encourage consistent editing style:
504	* Local Variables: *
505	* mode: c *
506	* fill-column: 75 *
507	* tab-width: 8 *
508	* c-basic-offset: 8 *
509	* End: *
510	*/