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1// SPDX-License-Identifier: GPL-2.0+
2// Expose the vboot context nvram to userspace
3//
4// Copyright (C) 2012 Google, Inc.
5// Copyright (C) 2015 Collabora Ltd.
6
7#include <linux/of.h>
8#include <linux/platform_device.h>
9#include <linux/module.h>
10#include <linux/platform_data/cros_ec_commands.h>
11#include <linux/platform_data/cros_ec_proto.h>
12#include <linux/slab.h>
13
14#define DRV_NAME "cros-ec-vbc"
15
16static ssize_t vboot_context_read(struct file *filp, struct kobject *kobj,
17 struct bin_attribute *att, char *buf,
18 loff_t pos, size_t count)
19{
20 struct device *dev = kobj_to_dev(kobj);
21 struct cros_ec_dev *ec = to_cros_ec_dev(dev);
22 struct cros_ec_device *ecdev = ec->ec_dev;
23 struct ec_params_vbnvcontext *params;
24 struct cros_ec_command *msg;
25 int err;
26 const size_t para_sz = sizeof(params->op);
27 const size_t resp_sz = sizeof(struct ec_response_vbnvcontext);
28 const size_t payload = max(para_sz, resp_sz);
29
30 msg = kmalloc(sizeof(*msg) + payload, GFP_KERNEL);
31 if (!msg)
32 return -ENOMEM;
33
34 /* NB: we only kmalloc()ated enough space for the op field */
35 params = (struct ec_params_vbnvcontext *)msg->data;
36 params->op = EC_VBNV_CONTEXT_OP_READ;
37
38 msg->version = EC_VER_VBNV_CONTEXT;
39 msg->command = EC_CMD_VBNV_CONTEXT;
40 msg->outsize = para_sz;
41 msg->insize = resp_sz;
42
43 err = cros_ec_cmd_xfer_status(ecdev, msg);
44 if (err < 0) {
45 dev_err(dev, "Error sending read request: %d\n", err);
46 kfree(msg);
47 return err;
48 }
49
50 memcpy(buf, msg->data, resp_sz);
51
52 kfree(msg);
53 return resp_sz;
54}
55
56static ssize_t vboot_context_write(struct file *filp, struct kobject *kobj,
57 struct bin_attribute *attr, char *buf,
58 loff_t pos, size_t count)
59{
60 struct device *dev = kobj_to_dev(kobj);
61 struct cros_ec_dev *ec = to_cros_ec_dev(dev);
62 struct cros_ec_device *ecdev = ec->ec_dev;
63 struct ec_params_vbnvcontext *params;
64 struct cros_ec_command *msg;
65 int err;
66 const size_t para_sz = sizeof(*params);
67 const size_t data_sz = sizeof(params->block);
68
69 /* Only write full values */
70 if (count != data_sz)
71 return -EINVAL;
72
73 msg = kmalloc(sizeof(*msg) + para_sz, GFP_KERNEL);
74 if (!msg)
75 return -ENOMEM;
76
77 params = (struct ec_params_vbnvcontext *)msg->data;
78 params->op = EC_VBNV_CONTEXT_OP_WRITE;
79 memcpy(params->block, buf, data_sz);
80
81 msg->version = EC_VER_VBNV_CONTEXT;
82 msg->command = EC_CMD_VBNV_CONTEXT;
83 msg->outsize = para_sz;
84 msg->insize = 0;
85
86 err = cros_ec_cmd_xfer_status(ecdev, msg);
87 if (err < 0) {
88 dev_err(dev, "Error sending write request: %d\n", err);
89 kfree(msg);
90 return err;
91 }
92
93 kfree(msg);
94 return data_sz;
95}
96
97static BIN_ATTR_RW(vboot_context, 16);
98
99static struct bin_attribute *cros_ec_vbc_bin_attrs[] = {
100 &bin_attr_vboot_context,
101 NULL
102};
103
104static const struct attribute_group cros_ec_vbc_attr_group = {
105 .name = "vbc",
106 .bin_attrs = cros_ec_vbc_bin_attrs,
107};
108
109static int cros_ec_vbc_probe(struct platform_device *pd)
110{
111 struct cros_ec_dev *ec_dev = dev_get_drvdata(pd->dev.parent);
112 struct device *dev = &pd->dev;
113 int ret;
114
115 ret = sysfs_create_group(&ec_dev->class_dev.kobj,
116 &cros_ec_vbc_attr_group);
117 if (ret < 0)
118 dev_err(dev, "failed to create %s attributes. err=%d\n",
119 cros_ec_vbc_attr_group.name, ret);
120
121 return ret;
122}
123
124static int cros_ec_vbc_remove(struct platform_device *pd)
125{
126 struct cros_ec_dev *ec_dev = dev_get_drvdata(pd->dev.parent);
127
128 sysfs_remove_group(&ec_dev->class_dev.kobj,
129 &cros_ec_vbc_attr_group);
130
131 return 0;
132}
133
134static struct platform_driver cros_ec_vbc_driver = {
135 .driver = {
136 .name = DRV_NAME,
137 },
138 .probe = cros_ec_vbc_probe,
139 .remove = cros_ec_vbc_remove,
140};
141
142module_platform_driver(cros_ec_vbc_driver);
143
144MODULE_LICENSE("GPL");
145MODULE_DESCRIPTION("Expose the vboot context nvram to userspace");
146MODULE_ALIAS("platform:" DRV_NAME);
1// SPDX-License-Identifier: GPL-2.0+
2// Expose the vboot context nvram to userspace
3//
4// Copyright (C) 2012 Google, Inc.
5// Copyright (C) 2015 Collabora Ltd.
6
7#include <linux/of.h>
8#include <linux/platform_device.h>
9#include <linux/mfd/cros_ec.h>
10#include <linux/module.h>
11#include <linux/platform_data/cros_ec_commands.h>
12#include <linux/platform_data/cros_ec_proto.h>
13#include <linux/slab.h>
14
15#define DRV_NAME "cros-ec-vbc"
16
17static ssize_t vboot_context_read(struct file *filp, struct kobject *kobj,
18 struct bin_attribute *att, char *buf,
19 loff_t pos, size_t count)
20{
21 struct device *dev = container_of(kobj, struct device, kobj);
22 struct cros_ec_dev *ec = to_cros_ec_dev(dev);
23 struct cros_ec_device *ecdev = ec->ec_dev;
24 struct ec_params_vbnvcontext *params;
25 struct cros_ec_command *msg;
26 int err;
27 const size_t para_sz = sizeof(params->op);
28 const size_t resp_sz = sizeof(struct ec_response_vbnvcontext);
29 const size_t payload = max(para_sz, resp_sz);
30
31 msg = kmalloc(sizeof(*msg) + payload, GFP_KERNEL);
32 if (!msg)
33 return -ENOMEM;
34
35 /* NB: we only kmalloc()ated enough space for the op field */
36 params = (struct ec_params_vbnvcontext *)msg->data;
37 params->op = EC_VBNV_CONTEXT_OP_READ;
38
39 msg->version = EC_VER_VBNV_CONTEXT;
40 msg->command = EC_CMD_VBNV_CONTEXT;
41 msg->outsize = para_sz;
42 msg->insize = resp_sz;
43
44 err = cros_ec_cmd_xfer(ecdev, msg);
45 if (err < 0) {
46 dev_err(dev, "Error sending read request: %d\n", err);
47 kfree(msg);
48 return err;
49 }
50
51 memcpy(buf, msg->data, resp_sz);
52
53 kfree(msg);
54 return resp_sz;
55}
56
57static ssize_t vboot_context_write(struct file *filp, struct kobject *kobj,
58 struct bin_attribute *attr, char *buf,
59 loff_t pos, size_t count)
60{
61 struct device *dev = container_of(kobj, struct device, kobj);
62 struct cros_ec_dev *ec = to_cros_ec_dev(dev);
63 struct cros_ec_device *ecdev = ec->ec_dev;
64 struct ec_params_vbnvcontext *params;
65 struct cros_ec_command *msg;
66 int err;
67 const size_t para_sz = sizeof(*params);
68 const size_t data_sz = sizeof(params->block);
69
70 /* Only write full values */
71 if (count != data_sz)
72 return -EINVAL;
73
74 msg = kmalloc(sizeof(*msg) + para_sz, GFP_KERNEL);
75 if (!msg)
76 return -ENOMEM;
77
78 params = (struct ec_params_vbnvcontext *)msg->data;
79 params->op = EC_VBNV_CONTEXT_OP_WRITE;
80 memcpy(params->block, buf, data_sz);
81
82 msg->version = EC_VER_VBNV_CONTEXT;
83 msg->command = EC_CMD_VBNV_CONTEXT;
84 msg->outsize = para_sz;
85 msg->insize = 0;
86
87 err = cros_ec_cmd_xfer(ecdev, msg);
88 if (err < 0) {
89 dev_err(dev, "Error sending write request: %d\n", err);
90 kfree(msg);
91 return err;
92 }
93
94 kfree(msg);
95 return data_sz;
96}
97
98static BIN_ATTR_RW(vboot_context, 16);
99
100static struct bin_attribute *cros_ec_vbc_bin_attrs[] = {
101 &bin_attr_vboot_context,
102 NULL
103};
104
105static struct attribute_group cros_ec_vbc_attr_group = {
106 .name = "vbc",
107 .bin_attrs = cros_ec_vbc_bin_attrs,
108};
109
110static int cros_ec_vbc_probe(struct platform_device *pd)
111{
112 struct cros_ec_dev *ec_dev = dev_get_drvdata(pd->dev.parent);
113 struct device *dev = &pd->dev;
114 int ret;
115
116 ret = sysfs_create_group(&ec_dev->class_dev.kobj,
117 &cros_ec_vbc_attr_group);
118 if (ret < 0)
119 dev_err(dev, "failed to create %s attributes. err=%d\n",
120 cros_ec_vbc_attr_group.name, ret);
121
122 return ret;
123}
124
125static int cros_ec_vbc_remove(struct platform_device *pd)
126{
127 struct cros_ec_dev *ec_dev = dev_get_drvdata(pd->dev.parent);
128
129 sysfs_remove_group(&ec_dev->class_dev.kobj,
130 &cros_ec_vbc_attr_group);
131
132 return 0;
133}
134
135static struct platform_driver cros_ec_vbc_driver = {
136 .driver = {
137 .name = DRV_NAME,
138 },
139 .probe = cros_ec_vbc_probe,
140 .remove = cros_ec_vbc_remove,
141};
142
143module_platform_driver(cros_ec_vbc_driver);
144
145MODULE_LICENSE("GPL");
146MODULE_DESCRIPTION("Expose the vboot context nvram to userspace");
147MODULE_ALIAS("platform:" DRV_NAME);