/*
*
* $Id: pvrusb2-ioread.c,v 1.2 2006/01/23 06:58:06 mcisely 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 "compat.h"
#include "pvrusb2-ioread.h"
#include "pvrusb2-debug.h"
#include <linux/errno.h>
#include <linux/string.h>
#include <linux/slab.h>
#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,16)
#include <asm/atomic.h>
#include <asm/mutex.h>
#else
#include <asm/semaphore.h>
#endif
#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;
#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,16)
struct mutex mutex;
#else
struct semaphore mutex;
#endif
};
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);
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;
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_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;
mutex_lock(&cp->mutex); 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); 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: ***
*/