diff options
Diffstat (limited to 'drivers/media/video/saa7164/saa7164-buffer.c')
| -rw-r--r-- | drivers/media/video/saa7164/saa7164-buffer.c | 155 |
1 files changed, 155 insertions, 0 deletions
diff --git a/drivers/media/video/saa7164/saa7164-buffer.c b/drivers/media/video/saa7164/saa7164-buffer.c new file mode 100644 index 00000000000..9ca5c83d165 --- /dev/null +++ b/drivers/media/video/saa7164/saa7164-buffer.c @@ -0,0 +1,155 @@ +/* + * 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 "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 = port->dev; + + if ((buf == 0) || (port == 0)) + return SAA_ERR_BAD_PARAMETER; + + 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; +} + |