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
160
161
162
163
164
165
166
167
|
// SPDX-License-Identifier: GPL-2.0-only
/*
* Copyright (c) 2013-2014, NVIDIA CORPORATION. All rights reserved.
*
* Based on drivers/misc/eeprom/sunxi_sid.c
*/
#include <linux/device.h>
#include <linux/clk.h>
#include <linux/completion.h>
#include <linux/dmaengine.h>
#include <linux/dma-mapping.h>
#include <linux/err.h>
#include <linux/io.h>
#include <linux/kernel.h>
#include <linux/kobject.h>
#include <linux/of_device.h>
#include <linux/platform_device.h>
#include <linux/random.h>
#include <soc/tegra/fuse.h>
#include "fuse.h"
#define FUSE_BEGIN 0x100
#define FUSE_UID_LOW 0x08
#define FUSE_UID_HIGH 0x0c
static u32 tegra20_fuse_read_early(struct tegra_fuse *fuse, unsigned int offset)
{
return readl_relaxed(fuse->base + FUSE_BEGIN + offset);
}
static void apb_dma_complete(void *args)
{
struct tegra_fuse *fuse = args;
complete(&fuse->apbdma.wait);
}
static u32 tegra20_fuse_read(struct tegra_fuse *fuse, unsigned int offset)
{
unsigned long flags = DMA_PREP_INTERRUPT | DMA_CTRL_ACK;
struct dma_async_tx_descriptor *dma_desc;
unsigned long time_left;
u32 value = 0;
int err;
mutex_lock(&fuse->apbdma.lock);
fuse->apbdma.config.src_addr = fuse->phys + FUSE_BEGIN + offset;
err = dmaengine_slave_config(fuse->apbdma.chan, &fuse->apbdma.config);
if (err)
goto out;
dma_desc = dmaengine_prep_slave_single(fuse->apbdma.chan,
fuse->apbdma.phys,
sizeof(u32), DMA_DEV_TO_MEM,
flags);
if (!dma_desc)
goto out;
dma_desc->callback = apb_dma_complete;
dma_desc->callback_param = fuse;
reinit_completion(&fuse->apbdma.wait);
clk_prepare_enable(fuse->clk);
dmaengine_submit(dma_desc);
dma_async_issue_pending(fuse->apbdma.chan);
time_left = wait_for_completion_timeout(&fuse->apbdma.wait,
msecs_to_jiffies(50));
if (WARN(time_left == 0, "apb read dma timed out"))
dmaengine_terminate_all(fuse->apbdma.chan);
else
value = *fuse->apbdma.virt;
clk_disable_unprepare(fuse->clk);
out:
mutex_unlock(&fuse->apbdma.lock);
return value;
}
static bool dma_filter(struct dma_chan *chan, void *filter_param)
{
struct device_node *np = chan->device->dev->of_node;
return of_device_is_compatible(np, "nvidia,tegra20-apbdma");
}
static int tegra20_fuse_probe(struct tegra_fuse *fuse)
{
dma_cap_mask_t mask;
dma_cap_zero(mask);
dma_cap_set(DMA_SLAVE, mask);
fuse->apbdma.chan = __dma_request_channel(&mask, dma_filter, NULL);
if (!fuse->apbdma.chan)
return -EPROBE_DEFER;
fuse->apbdma.virt = dma_alloc_coherent(fuse->dev, sizeof(u32),
&fuse->apbdma.phys,
GFP_KERNEL);
if (!fuse->apbdma.virt) {
dma_release_channel(fuse->apbdma.chan);
return -ENOMEM;
}
fuse->apbdma.config.src_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES;
fuse->apbdma.config.dst_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES;
fuse->apbdma.config.src_maxburst = 1;
fuse->apbdma.config.dst_maxburst = 1;
fuse->apbdma.config.direction = DMA_DEV_TO_MEM;
fuse->apbdma.config.device_fc = false;
init_completion(&fuse->apbdma.wait);
mutex_init(&fuse->apbdma.lock);
fuse->read = tegra20_fuse_read;
return 0;
}
static const struct tegra_fuse_info tegra20_fuse_info = {
.read = tegra20_fuse_read,
.size = 0x1f8,
.spare = 0x100,
};
/* Early boot code. This code is called before the devices are created */
static void __init tegra20_fuse_add_randomness(void)
{
u32 randomness[7];
randomness[0] = tegra_sku_info.sku_id;
randomness[1] = tegra_read_straps();
randomness[2] = tegra_read_chipid();
randomness[3] = tegra_sku_info.cpu_process_id << 16;
randomness[3] |= tegra_sku_info.soc_process_id;
randomness[4] = tegra_sku_info.cpu_speedo_id << 16;
randomness[4] |= tegra_sku_info.soc_speedo_id;
randomness[5] = tegra_fuse_read_early(FUSE_UID_LOW);
randomness[6] = tegra_fuse_read_early(FUSE_UID_HIGH);
add_device_randomness(randomness, sizeof(randomness));
}
static void __init tegra20_fuse_init(struct tegra_fuse *fuse)
{
fuse->read_early = tegra20_fuse_read_early;
tegra_init_revision();
fuse->soc->speedo_init(&tegra_sku_info);
tegra20_fuse_add_randomness();
}
const struct tegra_fuse_soc tegra20_fuse_soc = {
.init = tegra20_fuse_init,
.speedo_init = tegra20_init_speedo_data,
.probe = tegra20_fuse_probe,
.info = &tegra20_fuse_info,
};
|
