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
|
/*
* cros_ec_vbc - Expose the vboot context nvram to userspace
*
* Copyright (C) 2015 Collabora Ltd.
*
* based on vendor driver,
*
* Copyright (C) 2012 The Chromium OS Authors
*
* 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.
*/
#include <linux/of.h>
#include <linux/platform_device.h>
#include <linux/mfd/cros_ec.h>
#include <linux/mfd/cros_ec_commands.h>
#include <linux/slab.h>
static ssize_t vboot_context_read(struct file *filp, struct kobject *kobj,
struct bin_attribute *att, char *buf,
loff_t pos, size_t count)
{
struct device *dev = container_of(kobj, struct device, kobj);
struct cros_ec_dev *ec = container_of(dev, struct cros_ec_dev,
class_dev);
struct cros_ec_device *ecdev = ec->ec_dev;
struct ec_params_vbnvcontext *params;
struct cros_ec_command *msg;
int err;
const size_t para_sz = sizeof(params->op);
const size_t resp_sz = sizeof(struct ec_response_vbnvcontext);
const size_t payload = max(para_sz, resp_sz);
msg = kmalloc(sizeof(*msg) + payload, GFP_KERNEL);
if (!msg)
return -ENOMEM;
/* NB: we only kmalloc()ated enough space for the op field */
params = (struct ec_params_vbnvcontext *)msg->data;
params->op = EC_VBNV_CONTEXT_OP_READ;
msg->version = EC_VER_VBNV_CONTEXT;
msg->command = EC_CMD_VBNV_CONTEXT;
msg->outsize = para_sz;
msg->insize = resp_sz;
err = cros_ec_cmd_xfer(ecdev, msg);
if (err < 0) {
dev_err(dev, "Error sending read request: %d\n", err);
kfree(msg);
return err;
}
memcpy(buf, msg->data, resp_sz);
kfree(msg);
return resp_sz;
}
static ssize_t vboot_context_write(struct file *filp, struct kobject *kobj,
struct bin_attribute *attr, char *buf,
loff_t pos, size_t count)
{
struct device *dev = container_of(kobj, struct device, kobj);
struct cros_ec_dev *ec = container_of(dev, struct cros_ec_dev,
class_dev);
struct cros_ec_device *ecdev = ec->ec_dev;
struct ec_params_vbnvcontext *params;
struct cros_ec_command *msg;
int err;
const size_t para_sz = sizeof(*params);
const size_t data_sz = sizeof(params->block);
/* Only write full values */
if (count != data_sz)
return -EINVAL;
msg = kmalloc(sizeof(*msg) + para_sz, GFP_KERNEL);
if (!msg)
return -ENOMEM;
params = (struct ec_params_vbnvcontext *)msg->data;
params->op = EC_VBNV_CONTEXT_OP_WRITE;
memcpy(params->block, buf, data_sz);
msg->version = EC_VER_VBNV_CONTEXT;
msg->command = EC_CMD_VBNV_CONTEXT;
msg->outsize = para_sz;
msg->insize = 0;
err = cros_ec_cmd_xfer(ecdev, msg);
if (err < 0) {
dev_err(dev, "Error sending write request: %d\n", err);
kfree(msg);
return err;
}
kfree(msg);
return data_sz;
}
static umode_t cros_ec_vbc_is_visible(struct kobject *kobj,
struct bin_attribute *a, int n)
{
struct device *dev = container_of(kobj, struct device, kobj);
struct cros_ec_dev *ec = container_of(dev, struct cros_ec_dev,
class_dev);
struct device_node *np = ec->ec_dev->dev->of_node;
if (IS_ENABLED(CONFIG_OF) && np) {
if (of_property_read_bool(np, "google,has-vbc-nvram"))
return a->attr.mode;
}
return 0;
}
static BIN_ATTR_RW(vboot_context, 16);
static struct bin_attribute *cros_ec_vbc_bin_attrs[] = {
&bin_attr_vboot_context,
NULL
};
struct attribute_group cros_ec_vbc_attr_group = {
.name = "vbc",
.bin_attrs = cros_ec_vbc_bin_attrs,
.is_bin_visible = cros_ec_vbc_is_visible,
};
|
