summaryrefslogtreecommitdiffstats
path: root/drivers/platform/chrome/cros_ec_vbc.c
diff options
context:
space:
mode:
authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-07 18:49:45 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-07 18:49:45 +0000
commit2c3c1048746a4622d8c89a29670120dc8fab93c4 (patch)
tree848558de17fb3008cdf4d861b01ac7781903ce39 /drivers/platform/chrome/cros_ec_vbc.c
parentInitial commit. (diff)
downloadlinux-2c3c1048746a4622d8c89a29670120dc8fab93c4.tar.xz
linux-2c3c1048746a4622d8c89a29670120dc8fab93c4.zip
Adding upstream version 6.1.76.upstream/6.1.76
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'drivers/platform/chrome/cros_ec_vbc.c')
-rw-r--r--drivers/platform/chrome/cros_ec_vbc.c146
1 files changed, 146 insertions, 0 deletions
diff --git a/drivers/platform/chrome/cros_ec_vbc.c b/drivers/platform/chrome/cros_ec_vbc.c
new file mode 100644
index 000000000..c859c862d
--- /dev/null
+++ b/drivers/platform/chrome/cros_ec_vbc.c
@@ -0,0 +1,146 @@
+// 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/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 = kobj_to_dev(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_status(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 = kobj_to_dev(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_status(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 const 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);