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146 lines
3.6 KiB
146 lines
3.6 KiB
// SPDX-License-Identifier: GPL-2.0+ |
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// Expose the vboot context nvram to userspace |
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// |
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// Copyright (C) 2012 Google, Inc. |
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// Copyright (C) 2015 Collabora Ltd. |
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#include <linux/of.h> |
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#include <linux/platform_device.h> |
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#include <linux/module.h> |
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#include <linux/platform_data/cros_ec_commands.h> |
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#include <linux/platform_data/cros_ec_proto.h> |
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#include <linux/slab.h> |
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#define DRV_NAME "cros-ec-vbc" |
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static ssize_t vboot_context_read(struct file *filp, struct kobject *kobj, |
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struct bin_attribute *att, char *buf, |
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loff_t pos, size_t count) |
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{ |
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struct device *dev = kobj_to_dev(kobj); |
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struct cros_ec_dev *ec = to_cros_ec_dev(dev); |
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struct cros_ec_device *ecdev = ec->ec_dev; |
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struct ec_params_vbnvcontext *params; |
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struct cros_ec_command *msg; |
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int err; |
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const size_t para_sz = sizeof(params->op); |
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const size_t resp_sz = sizeof(struct ec_response_vbnvcontext); |
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const size_t payload = max(para_sz, resp_sz); |
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msg = kmalloc(sizeof(*msg) + payload, GFP_KERNEL); |
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if (!msg) |
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return -ENOMEM; |
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/* NB: we only kmalloc()ated enough space for the op field */ |
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params = (struct ec_params_vbnvcontext *)msg->data; |
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params->op = EC_VBNV_CONTEXT_OP_READ; |
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msg->version = EC_VER_VBNV_CONTEXT; |
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msg->command = EC_CMD_VBNV_CONTEXT; |
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msg->outsize = para_sz; |
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msg->insize = resp_sz; |
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err = cros_ec_cmd_xfer_status(ecdev, msg); |
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if (err < 0) { |
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dev_err(dev, "Error sending read request: %d\n", err); |
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kfree(msg); |
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return err; |
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} |
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memcpy(buf, msg->data, resp_sz); |
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kfree(msg); |
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return resp_sz; |
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} |
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static ssize_t vboot_context_write(struct file *filp, struct kobject *kobj, |
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struct bin_attribute *attr, char *buf, |
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loff_t pos, size_t count) |
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{ |
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struct device *dev = kobj_to_dev(kobj); |
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struct cros_ec_dev *ec = to_cros_ec_dev(dev); |
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struct cros_ec_device *ecdev = ec->ec_dev; |
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struct ec_params_vbnvcontext *params; |
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struct cros_ec_command *msg; |
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int err; |
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const size_t para_sz = sizeof(*params); |
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const size_t data_sz = sizeof(params->block); |
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/* Only write full values */ |
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if (count != data_sz) |
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return -EINVAL; |
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msg = kmalloc(sizeof(*msg) + para_sz, GFP_KERNEL); |
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if (!msg) |
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return -ENOMEM; |
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params = (struct ec_params_vbnvcontext *)msg->data; |
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params->op = EC_VBNV_CONTEXT_OP_WRITE; |
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memcpy(params->block, buf, data_sz); |
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msg->version = EC_VER_VBNV_CONTEXT; |
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msg->command = EC_CMD_VBNV_CONTEXT; |
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msg->outsize = para_sz; |
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msg->insize = 0; |
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err = cros_ec_cmd_xfer_status(ecdev, msg); |
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if (err < 0) { |
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dev_err(dev, "Error sending write request: %d\n", err); |
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kfree(msg); |
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return err; |
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} |
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kfree(msg); |
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return data_sz; |
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} |
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static BIN_ATTR_RW(vboot_context, 16); |
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static struct bin_attribute *cros_ec_vbc_bin_attrs[] = { |
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&bin_attr_vboot_context, |
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NULL |
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}; |
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static const struct attribute_group cros_ec_vbc_attr_group = { |
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.name = "vbc", |
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.bin_attrs = cros_ec_vbc_bin_attrs, |
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}; |
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static int cros_ec_vbc_probe(struct platform_device *pd) |
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{ |
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struct cros_ec_dev *ec_dev = dev_get_drvdata(pd->dev.parent); |
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struct device *dev = &pd->dev; |
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int ret; |
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ret = sysfs_create_group(&ec_dev->class_dev.kobj, |
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&cros_ec_vbc_attr_group); |
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if (ret < 0) |
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dev_err(dev, "failed to create %s attributes. err=%d\n", |
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cros_ec_vbc_attr_group.name, ret); |
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return ret; |
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} |
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static int cros_ec_vbc_remove(struct platform_device *pd) |
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{ |
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struct cros_ec_dev *ec_dev = dev_get_drvdata(pd->dev.parent); |
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sysfs_remove_group(&ec_dev->class_dev.kobj, |
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&cros_ec_vbc_attr_group); |
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return 0; |
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} |
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static struct platform_driver cros_ec_vbc_driver = { |
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.driver = { |
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.name = DRV_NAME, |
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}, |
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.probe = cros_ec_vbc_probe, |
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.remove = cros_ec_vbc_remove, |
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}; |
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module_platform_driver(cros_ec_vbc_driver); |
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MODULE_LICENSE("GPL"); |
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MODULE_DESCRIPTION("Expose the vboot context nvram to userspace"); |
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MODULE_ALIAS("platform:" DRV_NAME);
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