[deliverable/linux.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 = 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) 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;
ca545f7c	90	cp = kzalloc(sizeof(*cp),GFP_KERNEL);
a0fd1cb1	91	if (!cp) return NULL;
d855497e	92	pvr2_trace(PVR2_TRACE_STRUCT,"pvr2_ioread_create id=%p",cp);
d855497e MI	93	if (pvr2_ioread_init(cp) < 0) {
d855497e MI	94	kfree(cp);
a0fd1cb1	95	return NULL;
d855497e MI	96	}
	97	return cp;
	98	}
	99
	100	void pvr2_ioread_destroy(struct pvr2_ioread *cp)
	101	{
	102	if (!cp) return;
	103	pvr2_ioread_done(cp);
	104	pvr2_trace(PVR2_TRACE_STRUCT,"pvr2_ioread_destroy id=%p",cp);
	105	if (cp->sync_key_ptr) {
	106	kfree(cp->sync_key_ptr);
a0fd1cb1	107	cp->sync_key_ptr = NULL;
d855497e MI	108	}
	109	kfree(cp);
	110	}
	111
	112	void pvr2_ioread_set_sync_key(struct pvr2_ioread *cp,
	113	const char *sync_key_ptr,
	114	unsigned int sync_key_len)
	115	{
	116	if (!cp) return;
	117
	118	if (!sync_key_ptr) sync_key_len = 0;
	119	if ((sync_key_len == cp->sync_key_len) &&
	120	((!sync_key_len) \|\|
	121	(!memcmp(sync_key_ptr,cp->sync_key_ptr,sync_key_len)))) return;
	122
	123	if (sync_key_len != cp->sync_key_len) {
	124	if (cp->sync_key_ptr) {
	125	kfree(cp->sync_key_ptr);
a0fd1cb1	126	cp->sync_key_ptr = NULL;
d855497e MI	127	}
	128	cp->sync_key_len = 0;
	129	if (sync_key_len) {
	130	cp->sync_key_ptr = kmalloc(sync_key_len,GFP_KERNEL);
	131	if (cp->sync_key_ptr) {
	132	cp->sync_key_len = sync_key_len;
	133	}
	134	}
	135	}
	136	if (!cp->sync_key_len) return;
	137	memcpy(cp->sync_key_ptr,sync_key_ptr,cp->sync_key_len);
	138	}
	139
	140	static void pvr2_ioread_stop(struct pvr2_ioread *cp)
	141	{
	142	if (!(cp->enabled)) return;
	143	pvr2_trace(PVR2_TRACE_START_STOP,
	144	"/---TRACE_READ---/ pvr2_ioread_stop id=%p",cp);
	145	pvr2_stream_kill(cp->stream);
a0fd1cb1 MI	146	cp->c_buf = NULL;
a0fd1cb1 MI	147	cp->c_data_ptr = NULL;
d855497e MI	148	cp->c_data_len = 0;
	149	cp->c_data_offs = 0;
	150	cp->enabled = 0;
	151	cp->stream_running = 0;
	152	cp->spigot_open = 0;
	153	if (cp->sync_state) {
	154	pvr2_trace(PVR2_TRACE_DATA_FLOW,
	155	"/---TRACE_READ---/ sync_state <== 0");
	156	cp->sync_state = 0;
	157	}
	158	}
	159
	160	static int pvr2_ioread_start(struct pvr2_ioread *cp)
	161	{
	162	int stat;
	163	struct pvr2_buffer *bp;
	164	if (cp->enabled) return 0;
	165	if (!(cp->stream)) return 0;
	166	pvr2_trace(PVR2_TRACE_START_STOP,
	167	"/---TRACE_READ---/ pvr2_ioread_start id=%p",cp);
5fa1247a	168	while ((bp = pvr2_stream_get_idle_buffer(cp->stream)) != NULL) {
d855497e MI	169	stat = pvr2_buffer_queue(bp);
	170	if (stat < 0) {
	171	pvr2_trace(PVR2_TRACE_DATA_FLOW,
	172	"/---TRACE_READ---/"
	173	" pvr2_ioread_start id=%p"
	174	" error=%d",
	175	cp,stat);
	176	pvr2_ioread_stop(cp);
	177	return stat;
	178	}
	179	}
	180	cp->enabled = !0;
a0fd1cb1 MI	181	cp->c_buf = NULL;
a0fd1cb1 MI	182	cp->c_data_ptr = NULL;
d855497e MI	183	cp->c_data_len = 0;
	184	cp->c_data_offs = 0;
	185	cp->stream_running = 0;
	186	if (cp->sync_key_len) {
	187	pvr2_trace(PVR2_TRACE_DATA_FLOW,
	188	"/---TRACE_READ---/ sync_state <== 1");
	189	cp->sync_state = 1;
	190	cp->sync_trashed_count = 0;
	191	cp->sync_buf_offs = 0;
	192	}
	193	cp->spigot_open = 0;
	194	return 0;
	195	}
	196
	197	struct pvr2_stream pvr2_ioread_get_stream(struct pvr2_ioread cp)
	198	{
	199	return cp->stream;
	200	}
	201
	202	int pvr2_ioread_setup(struct pvr2_ioread cp,struct pvr2_stream sp)
	203	{
	204	int ret;
	205	unsigned int idx;
	206	struct pvr2_buffer *bp;
	207
	208	mutex_lock(&cp->mutex); do {
	209	if (cp->stream) {
	210	pvr2_trace(PVR2_TRACE_START_STOP,
	211	"/---TRACE_READ---/"
	212	" pvr2_ioread_setup (tear-down) id=%p",cp);
	213	pvr2_ioread_stop(cp);
	214	pvr2_stream_kill(cp->stream);
e61b6fc5 MI	215	if (pvr2_stream_get_buffer_count(cp->stream)) {
	216	pvr2_stream_set_buffer_count(cp->stream,0);
	217	}
a0fd1cb1	218	cp->stream = NULL;
d855497e MI	219	}
	220	if (sp) {
	221	pvr2_trace(PVR2_TRACE_START_STOP,
	222	"/---TRACE_READ---/"
	223	" pvr2_ioread_setup (setup) id=%p",cp);
	224	pvr2_stream_kill(sp);
	225	ret = pvr2_stream_set_buffer_count(sp,BUFFER_COUNT);
	226	if (ret < 0) return ret;
	227	for (idx = 0; idx < BUFFER_COUNT; idx++) {
	228	bp = pvr2_stream_get_buffer(sp,idx);
	229	pvr2_buffer_set_buffer(bp,
	230	cp->buffer_storage[idx],
	231	BUFFER_SIZE);
	232	}
	233	cp->stream = sp;
	234	}
	235	} while (0); mutex_unlock(&cp->mutex);
	236
	237	return 0;
	238	}
	239
	240	int pvr2_ioread_set_enabled(struct pvr2_ioread *cp,int fl)
	241	{
	242	int ret = 0;
	243	if ((!fl) == (!(cp->enabled))) return ret;
	244
	245	mutex_lock(&cp->mutex); do {
	246	if (fl) {
	247	ret = pvr2_ioread_start(cp);
	248	} else {
	249	pvr2_ioread_stop(cp);
	250	}
	251	} while (0); mutex_unlock(&cp->mutex);
	252	return ret;
	253	}
	254
07e337ee	255	static int pvr2_ioread_get_buffer(struct pvr2_ioread *cp)
d855497e MI	256	{
	257	int stat;
	258
	259	while (cp->c_data_len <= cp->c_data_offs) {
	260	if (cp->c_buf) {
	261	// Flush out current buffer first.
	262	stat = pvr2_buffer_queue(cp->c_buf);
	263	if (stat < 0) {
	264	// Streaming error...
	265	pvr2_trace(PVR2_TRACE_DATA_FLOW,
	266	"/---TRACE_READ---/"
	267	" pvr2_ioread_read id=%p"
	268	" queue_error=%d",
	269	cp,stat);
	270	pvr2_ioread_stop(cp);
	271	return 0;
	272	}
a0fd1cb1 MI	273	cp->c_buf = NULL;
a0fd1cb1 MI	274	cp->c_data_ptr = NULL;
d855497e MI	275	cp->c_data_len = 0;
	276	cp->c_data_offs = 0;
	277	}
	278	// Now get a freshly filled buffer.
	279	cp->c_buf = pvr2_stream_get_ready_buffer(cp->stream);
	280	if (!cp->c_buf) break; // Nothing ready; done.
	281	cp->c_data_len = pvr2_buffer_get_count(cp->c_buf);
	282	if (!cp->c_data_len) {
	283	// Nothing transferred. Was there an error?
	284	stat = pvr2_buffer_get_status(cp->c_buf);
	285	if (stat < 0) {
	286	// Streaming error...
	287	pvr2_trace(PVR2_TRACE_DATA_FLOW,
	288	"/---TRACE_READ---/"
	289	" pvr2_ioread_read id=%p"
	290	" buffer_error=%d",
	291	cp,stat);
	292	pvr2_ioread_stop(cp);
	293	// Give up.
	294	return 0;
	295	}
	296	// Start over...
	297	continue;
	298	}
	299	cp->c_data_offs = 0;
	300	cp->c_data_ptr = cp->buffer_storage[
	301	pvr2_buffer_get_id(cp->c_buf)];
	302	}
	303	return !0;
	304	}
	305
07e337ee	306	static void pvr2_ioread_filter(struct pvr2_ioread *cp)
d855497e MI	307	{
	308	unsigned int idx;
	309	if (!cp->enabled) return;
	310	if (cp->sync_state != 1) return;
	311
	312	// Search the stream for our synchronization key. This is made
	313	// complicated by the fact that in order to be honest with
	314	// ourselves here we must search across buffer boundaries...
	315	mutex_lock(&cp->mutex); while (1) {
	316	// Ensure we have a buffer
	317	if (!pvr2_ioread_get_buffer(cp)) break;
	318	if (!cp->c_data_len) break;
	319
	320	// Now walk the buffer contents until we match the key or
	321	// run out of buffer data.
	322	for (idx = cp->c_data_offs; idx < cp->c_data_len; idx++) {
	323	if (cp->sync_buf_offs >= cp->sync_key_len) break;
	324	if (cp->c_data_ptr[idx] ==
	325	cp->sync_key_ptr[cp->sync_buf_offs]) {
	326	// Found the next key byte
	327	(cp->sync_buf_offs)++;
	328	} else {
	329	// Whoops, mismatched. Start key over...
	330	cp->sync_buf_offs = 0;
	331	}
	332	}
	333
	334	// Consume what we've walked through
	335	cp->c_data_offs += idx;
	336	cp->sync_trashed_count += idx;
	337
	338	// If we've found the key, then update state and get out.
	339	if (cp->sync_buf_offs >= cp->sync_key_len) {
	340	cp->sync_trashed_count -= cp->sync_key_len;
	341	pvr2_trace(PVR2_TRACE_DATA_FLOW,
	342	"/---TRACE_READ---/"
	343	" sync_state <== 2 (skipped %u bytes)",
	344	cp->sync_trashed_count);
	345	cp->sync_state = 2;
	346	cp->sync_buf_offs = 0;
	347	break;
	348	}
	349
	350	if (cp->c_data_offs < cp->c_data_len) {
	351	// Sanity check - should NEVER get here
	352	pvr2_trace(PVR2_TRACE_ERROR_LEGS,
	353	"ERROR: pvr2_ioread filter sync problem"
	354	" len=%u offs=%u",
	355	cp->c_data_len,cp->c_data_offs);
	356	// Get out so we don't get stuck in an infinite
	357	// loop.
	358	break;
	359	}
	360
	361	continue; // (for clarity)
	362	} mutex_unlock(&cp->mutex);
	363	}
	364
	365	int pvr2_ioread_avail(struct pvr2_ioread *cp)
	366	{
	367	int ret;
	368	if (!(cp->enabled)) {
	369	// Stream is not enabled; so this is an I/O error
	370	return -EIO;
371	}
372
373	if (cp->sync_state == 1) {
374	pvr2_ioread_filter(cp);
375	if (cp->sync_state == 1) return -EAGAIN;
376	}
377
378	ret = 0;
379	if (cp->stream_running) {
380	if (!pvr2_stream_get_ready_count(cp->stream)) {
381	// No data available at all right now.
382	ret = -EAGAIN;
383	}
384	} else {
385	if (pvr2_stream_get_ready_count(cp->stream) < BUFFER_COUNT/2) {
386	// Haven't buffered up enough yet; try again later
387	ret = -EAGAIN;
388	}
389	}
390
391	if ((!(cp->spigot_open)) != (!(ret == 0))) {
392	cp->spigot_open = (ret == 0);
393	pvr2_trace(PVR2_TRACE_DATA_FLOW,
394	"/---TRACE_READ---/ data is %s",
395	cp->spigot_open ? "available" : "pending");
396	}
397
398	return ret;
399	}
400
401	int pvr2_ioread_read(struct pvr2_ioread cp,void __user buf,unsigned int cnt)
402	{
403	unsigned int copied_cnt;
404	unsigned int bcnt;
405	const char *src;
406	int stat;
407	int ret = 0;
408	unsigned int req_cnt = cnt;
409
410	if (!cnt) {
411	pvr2_trace(PVR2_TRACE_TRAP,
412	"/---TRACE_READ---/ pvr2_ioread_read id=%p"
413	" ZERO Request? Returning zero.",cp);
414	return 0;
415	}
416
417	stat = pvr2_ioread_avail(cp);
418	if (stat < 0) return stat;
419
420	cp->stream_running = !0;
421
422	mutex_lock(&cp->mutex); do {
423
424	// Suck data out of the buffers and copy to the user
425	copied_cnt = 0;
426	if (!buf) cnt = 0;
427	while (1) {
428	if (!pvr2_ioread_get_buffer(cp)) {
429	ret = -EIO;
430	break;
431	}
432
433	if (!cnt) break;
434
435	if (cp->sync_state == 2) {
436	// We're repeating the sync key data into
437	// the stream.
438	src = cp->sync_key_ptr + cp->sync_buf_offs;
439	bcnt = cp->sync_key_len - cp->sync_buf_offs;
440	} else {
441	// Normal buffer copy
442	src = cp->c_data_ptr + cp->c_data_offs;
443	bcnt = cp->c_data_len - cp->c_data_offs;
444	}
445
446	if (!bcnt) break;
447
448	// Don't run past user's buffer
449	if (bcnt > cnt) bcnt = cnt;
450
451	if (copy_to_user(buf,src,bcnt)) {
452	// User supplied a bad pointer?
453	// Give up - this will cause data
454	// to be lost.
455	ret = -EFAULT;
456	break;
457	}
458	cnt -= bcnt;
459	buf += bcnt;
460	copied_cnt += bcnt;
461
462	if (cp->sync_state == 2) {
463	// Update offset inside sync key that we're
464	// repeating back out.
465	cp->sync_buf_offs += bcnt;
466	if (cp->sync_buf_offs >= cp->sync_key_len) {
467	// Consumed entire key; switch mode
468	// to normal.
469	pvr2_trace(PVR2_TRACE_DATA_FLOW,
470	"/---TRACE_READ---/"
471	" sync_state <== 0");
472	cp->sync_state = 0;
473	}
474	} else {
475	// Update buffer offset.
476	cp->c_data_offs += bcnt;
477	}
478	}
479
480	} while (0); mutex_unlock(&cp->mutex);
481
482	if (!ret) {
483	if (copied_cnt) {
484	// If anything was copied, return that count
485	ret = copied_cnt;
486	} else {
487	// Nothing copied; suggest to caller that another
488	// attempt should be tried again later
489	ret = -EAGAIN;
490	}
491	}
492
493	pvr2_trace(PVR2_TRACE_DATA_FLOW,
494	"/---TRACE_READ---/ pvr2_ioread_read"
495	" id=%p request=%d result=%d",
496	cp,req_cnt,ret);
497	return ret;
498	}
499
500
501	/*
502	Stuff for Emacs to see, in order to encourage consistent editing style:
503	* Local Variables: *
504	* mode: c *
505	* fill-column: 75 *
506	* tab-width: 8 *
507	* c-basic-offset: 8 *
508	* End: *
509	*/