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
|
// SPDX-License-Identifier: GPL-2.0+
// Expose the vboot context nvram to userspace
//
// Copyright (C) 2012 Google, Inc.
// Copyright (C) 2015 Collabora Ltd.
#include <linux/of.h>
#include <linux/platform_device.h>
#include <linux/mfd/cros_ec.h>
#include <linux/module.h>
#include <linux/platform_data/cros_ec_commands.h>
#include <linux/platform_data/cros_ec_proto.h>
#include <linux/slab.h>
#define DRV_NAME "cros-ec-vbc"
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 = to_cros_ec_dev(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 = to_cros_ec_dev(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 BIN_ATTR_RW(vboot_context, 16);
static struct bin_attribute *cros_ec_vbc_bin_attrs[] = {
&bin_attr_vboot_context,
NULL
};
static struct attribute_group cros_ec_vbc_attr_group = {
.name = "vbc",
.bin_attrs = cros_ec_vbc_bin_attrs,
};
static int cros_ec_vbc_probe(struct platform_device *pd)
{
struct cros_ec_dev *ec_dev = dev_get_drvdata(pd->dev.parent);
struct device *dev = &pd->dev;
int ret;
ret = sysfs_create_group(&ec_dev->class_dev.kobj,
&cros_ec_vbc_attr_group);
if (ret < 0)
dev_err(dev, "failed to create %s attributes. err=%d\n",
cros_ec_vbc_attr_group.name, ret);
return ret;
}
static int cros_ec_vbc_remove(struct platform_device *pd)
{
struct cros_ec_dev *ec_dev = dev_get_drvdata(pd->dev.parent);
sysfs_remove_group(&ec_dev->class_dev.kobj,
&cros_ec_vbc_attr_group);
return 0;
}
static struct platform_driver cros_ec_vbc_driver = {
.driver = {
.name = DRV_NAME,
},
.probe = cros_ec_vbc_probe,
.remove = cros_ec_vbc_remove,
};
module_platform_driver(cros_ec_vbc_driver);
MODULE_LICENSE("GPL");
MODULE_DESCRIPTION("Expose the vboot context nvram to userspace");
MODULE_ALIAS("platform:" DRV_NAME);
|
