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
156
157
158
159
|
/*
* (C) Copyright 2010,2011
* NVIDIA Corporation <www.nvidia.com>
* Copyright 2014 Google Inc.
*
* This program is free software; you can redistribute it and/or modify it
* under the terms and conditions of the GNU General Public License,
* version 2, as published by the Free Software Foundation.
*
* This program is distributed in the hope 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, see <http://www.gnu.org/licenses/>.
*/
#include <arch/io.h>
#include <console/console.h>
#include <inttypes.h>
#include <soc/addressmap.h>
#include <soc/dma.h>
#include <stddef.h>
#include <stdlib.h>
struct apb_dma * const apb_dma = (struct apb_dma *)TEGRA_APB_DMA_BASE;
#define APB_DMA_OFFSET(n) \
(struct apb_dma_channel_regs *)(TEGRA_APB_DMA_BASE + n)
struct apb_dma_channel apb_dma_channels[] = {
{ .num = 0, .regs = APB_DMA_OFFSET(0x1000) },
{ .num = 1, .regs = APB_DMA_OFFSET(0x1040) },
{ .num = 2, .regs = APB_DMA_OFFSET(0x1080) },
{ .num = 3, .regs = APB_DMA_OFFSET(0x10c0) },
{ .num = 4, .regs = APB_DMA_OFFSET(0x1100) },
{ .num = 5, .regs = APB_DMA_OFFSET(0x1140) },
{ .num = 6, .regs = APB_DMA_OFFSET(0x1180) },
{ .num = 7, .regs = APB_DMA_OFFSET(0x11c0) },
{ .num = 8, .regs = APB_DMA_OFFSET(0x1200) },
{ .num = 9, .regs = APB_DMA_OFFSET(0x1240) },
{ .num = 10, .regs = APB_DMA_OFFSET(0x1280) },
{ .num = 11, .regs = APB_DMA_OFFSET(0x12c0) },
{ .num = 12, .regs = APB_DMA_OFFSET(0x1300) },
{ .num = 13, .regs = APB_DMA_OFFSET(0x1340) },
{ .num = 14, .regs = APB_DMA_OFFSET(0x1380) },
{ .num = 15, .regs = APB_DMA_OFFSET(0x13c0) },
{ .num = 16, .regs = APB_DMA_OFFSET(0x1400) },
{ .num = 17, .regs = APB_DMA_OFFSET(0x1440) },
{ .num = 18, .regs = APB_DMA_OFFSET(0x1480) },
{ .num = 19, .regs = APB_DMA_OFFSET(0x14c0) },
{ .num = 20, .regs = APB_DMA_OFFSET(0x1500) },
{ .num = 21, .regs = APB_DMA_OFFSET(0x1540) },
{ .num = 22, .regs = APB_DMA_OFFSET(0x1580) },
{ .num = 23, .regs = APB_DMA_OFFSET(0x15c0) },
{ .num = 24, .regs = APB_DMA_OFFSET(0x1600) },
{ .num = 25, .regs = APB_DMA_OFFSET(0x1640) },
{ .num = 26, .regs = APB_DMA_OFFSET(0x1680) },
{ .num = 27, .regs = APB_DMA_OFFSET(0x16c0) },
{ .num = 28, .regs = APB_DMA_OFFSET(0x1700) },
{ .num = 29, .regs = APB_DMA_OFFSET(0x1740) },
{ .num = 30, .regs = APB_DMA_OFFSET(0x1780) },
{ .num = 31, .regs = APB_DMA_OFFSET(0x17c0) },
};
int dma_busy(struct apb_dma_channel * const channel)
{
/*
* In continuous mode, the BSY_n bit in APB_DMA_STATUS and
* BSY in APBDMACHAN_CHANNEL_n_STA_0 will remain set as '1' so long
* as the channel is enabled. So for this function we'll use the
* DMA_ACTIVITY bit in case of continuous mode.
*
* However, for ONCE mode, the BSY_n bit in APB_DMA_STATUS will be used
* to determine end of dma operation.
*/
uint32_t bit;
if (read32(&channel->regs->csr) & APB_CSR_ONCE)
/* Once mode */
bit = APB_STA_BSY;
else
/* Continuous mode */
bit = APB_STA_DMA_ACTIVITY;
return read32(&channel->regs->sta) & bit ? 1 : 0;
}
/* claim a DMA channel */
struct apb_dma_channel * const dma_claim(void)
{
int i;
struct apb_dma_channel_regs *regs = NULL;
/*
* Set global enable bit, otherwise register access to channel
* DMA registers will not be possible.
*/
setbits_le32(&apb_dma->command, APB_COMMAND_GEN);
for (i = 0; i < ARRAY_SIZE(apb_dma_channels); i++) {
regs = apb_dma_channels[i].regs;
if (!apb_dma_channels[i].in_use) {
u32 status = read32(®s->sta);
if (status & (1 << i)) {
/* FIXME: should this be fatal? */
printk(BIOS_DEBUG, "%s: DMA channel %d busy?\n",
__func__, i);
}
break;
}
}
if (i == ARRAY_SIZE(apb_dma_channels))
return NULL;
apb_dma_channels[i].in_use = 1;
return &apb_dma_channels[i];
}
/* release a DMA channel */
void dma_release(struct apb_dma_channel * const channel)
{
int i;
/* FIXME: make this "thread" friendly */
while (dma_busy(channel))
;
channel->in_use = 0;
/* clear the global enable bit if no channels are in use */
for (i = 0; i < ARRAY_SIZE(apb_dma_channels); i++) {
if (apb_dma_channels[i].in_use)
return;
}
clrbits_le32(&apb_dma->command, APB_COMMAND_GEN);
}
int dma_start(struct apb_dma_channel * const channel)
{
struct apb_dma_channel_regs *regs = channel->regs;
/* Set ENB bit for this channel */
setbits_le32(®s->csr, APB_CSR_ENB);
return 0;
}
int dma_stop(struct apb_dma_channel * const channel)
{
struct apb_dma_channel_regs *regs = channel->regs;
/* Clear ENB bit for this channel */
clrbits_le32(®s->csr, APB_CSR_ENB);
return 0;
}
|
