summaryrefslogtreecommitdiff
path: root/drivers/media/video/saa7164/saa7164-buffer.c
blob: 9ca5c83d165b636d410323e21a37bcb808f3a03f (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
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;
}