139 lines
3.8 KiB
C
139 lines
3.8 KiB
C
/*
|
|
* 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,
|
|
};
|
|
EXPORT_SYMBOL(cros_ec_vbc_attr_group);
|