/*
* Driver for the NXP SAA7164 PCIe bridge
*
* Copyright (c) 2009 Steven Toth <stoth@kernellabs.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, or
* (at your option) any later version.
*
* 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., 675 Mass Ave, Cambridge, MA 02139, USA.
*/
#include <linux/slab.h>
#include "saa7164.h"
/* The PCI address space for buffer handling looks like this:
+-u32 wide-------------+
| +
+-u64 wide------------------------------------+
+ +
+----------------------+
| CurrentBufferPtr + Pointer to current PCI buffer >-+
+----------------------+ |
| Unused + |
+----------------------+ |
| Pitch + = 188 (bytes) |
+----------------------+ |
| PCI buffer size + = pitch * number of lines (312) |
+----------------------+ |
|0| Buf0 Write Offset + |
+----------------------+ v
|1| Buf1 Write Offset + |
+----------------------+ |
|2| Buf2 Write Offset + |
+----------------------+ |
|3| Buf3 Write Offset + |
+----------------------+ |
... More write offsets |
+---------------------------------------------+ |
+0| set of ptrs to PCI pagetables + |
+---------------------------------------------+ |
+1| set of ptrs to PCI pagetables + <--------+
+---------------------------------------------+
+2| set of ptrs to PCI pagetables +
+---------------------------------------------+
+3| set of ptrs to PCI pagetables + >--+
+---------------------------------------------+ |
... More buffer pointers | +----------------+
+->| pt[0] TS data |
| +----------------+
|
| +----------------+
+->| pt[1] TS data |
| +----------------+
| etc
*/
/* Allocate a new buffer structure and associated PCI space in bytes.
* len must be a multiple of sizeof(u64)
*/
struct saa7164_buffer *saa7164_buffer_alloc(struct saa7164_tsport *port,
u32 len)
{
struct saa7164_buffer *buf = 0;
struct saa7164_dev *dev = port->dev;
int i;
if ((len == 0) || (len >= 65536) || (len % sizeof(u64))) {
log_warn("%s() SAA_ERR_BAD_PARAMETER\n", __func__);
goto ret;
}
buf = kzalloc(sizeof(struct saa7164_buffer), GFP_KERNEL);
if (buf == NULL) {
log_warn("%s() SAA_ERR_NO_RESOURCES\n", __func__);
goto ret;
}
buf->port = port;
buf->flags = SAA7164_BUFFER_FREE;
/* TODO: arg len is being ignored */
buf->pci_size = SAA7164_PT_ENTRIES * 0x1000;
buf->pt_size = (SAA7164_PT_ENTRIES * sizeof(u64)) + 0x1000;
/* Allocate contiguous memory */
buf->cpu = pci_alloc_consistent(port->dev->pci, buf->pci_size,
&buf->dma);
if (!buf->cpu)
goto fail1;
buf->pt_cpu = pci_alloc_consistent(port->dev->pci, buf->pt_size,
&buf->pt_dma);
if (!buf->pt_cpu)
goto fail2;
/* init the buffers to a known pattern, easier during debugging */
memset(buf->cpu, 0xff, buf->pci_size);
memset(buf->pt_cpu, 0xff, buf->pt_size);
dprintk(DBGLVL_BUF, "%s() allocated buffer @ 0x%p\n", __func__, buf);
dprintk(DBGLVL_BUF, " pci_cpu @ 0x%p dma @ 0x%08lx len = 0x%x\n",
buf->cpu, (long)buf->dma, buf->pci_size);
dprintk(DBGLVL_BUF, " pt_cpu @ 0x%p pt_dma @ 0x%08lx len = 0x%x\n",
buf->pt_cpu, (long)buf->pt_dma, buf->pt_size);
/* Format the Page Table Entries to point into the data buffer */
for (i = 0 ; i < SAA7164_PT_ENTRIES; i++) {
*(buf->pt_cpu + i) = buf->dma + (i * 0x1000); /* TODO */
}
goto ret;
fail2:
pci_free_consistent(port->dev->pci, buf->pci_size, buf->cpu, buf->dma);
fail1:
kfree(buf);
buf = 0;
ret:
return buf;
}
int saa7164_buffer_dealloc(struct saa7164_tsport *port,
struct saa7164_buffer *buf)
{
struct saa7164_dev *dev;
if (!buf || !port)
return SAA_ERR_BAD_PARAMETER;
dev = port->dev;
dprintk(DBGLVL_BUF, "%s() deallocating buffer @ 0x%p\n", __func__, buf);
if (buf->flags != SAA7164_BUFFER_FREE)
log_warn(" freeing a non-free buffer\n");
pci_free_consistent(port->dev->pci, buf->pci_size, buf->cpu, buf->dma);
pci_free_consistent(port->dev->pci, buf->pt_size, buf->pt_cpu,
buf->pt_dma);
kfree(buf);
return SAA_OK;
}
