+.. SPDX-License-Identifier: GPL-2.0
+
+==============================================
Intel(R) Management Engine (ME) Client bus API
==============================================
A driver implementation for an MEI Client is very similar to existing bus
based device drivers. The driver registers itself as an MEI CL bus driver through
-the mei_cl_driver structure:
+the ``struct mei_cl_driver`` structure:
+
+.. code-block:: C
-struct mei_cl_driver {
- struct device_driver driver;
- const char *name;
+ struct mei_cl_driver {
+ struct device_driver driver;
+ const char *name;
- const struct mei_cl_device_id *id_table;
+ const struct mei_cl_device_id *id_table;
- int (*probe)(struct mei_cl_device *dev, const struct mei_cl_id *id);
- int (*remove)(struct mei_cl_device *dev);
-};
+ int (*probe)(struct mei_cl_device *dev, const struct mei_cl_id *id);
+ int (*remove)(struct mei_cl_device *dev);
+ };
-struct mei_cl_id {
- char name[MEI_NAME_SIZE];
- kernel_ulong_t driver_info;
-};
+ struct mei_cl_id {
+ char name[MEI_NAME_SIZE];
+ kernel_ulong_t driver_info;
+ };
The mei_cl_id structure allows the driver to bind itself against a device name.
As a theoretical example let's pretend the ME comes with a "contact" NFC IP.
The driver init and exit routines for this device would look like:
-#define CONTACT_DRIVER_NAME "contact"
+.. code-block:: C
-static struct mei_cl_device_id contact_mei_cl_tbl[] = {
- { CONTACT_DRIVER_NAME, },
+ #define CONTACT_DRIVER_NAME "contact"
- /* required last entry */
- { }
-};
-MODULE_DEVICE_TABLE(mei_cl, contact_mei_cl_tbl);
+ static struct mei_cl_device_id contact_mei_cl_tbl[] = {
+ { CONTACT_DRIVER_NAME, },
-static struct mei_cl_driver contact_driver = {
- .id_table = contact_mei_tbl,
- .name = CONTACT_DRIVER_NAME,
+ /* required last entry */
+ { }
+ };
+ MODULE_DEVICE_TABLE(mei_cl, contact_mei_cl_tbl);
- .probe = contact_probe,
- .remove = contact_remove,
-};
+ static struct mei_cl_driver contact_driver = {
+ .id_table = contact_mei_tbl,
+ .name = CONTACT_DRIVER_NAME,
-static int contact_init(void)
-{
- int r;
+ .probe = contact_probe,
+ .remove = contact_remove,
+ };
- r = mei_cl_driver_register(&contact_driver);
- if (r) {
- pr_err(CONTACT_DRIVER_NAME ": driver registration failed\n");
- return r;
- }
+ static int contact_init(void)
+ {
+ int r;
+
+ r = mei_cl_driver_register(&contact_driver);
+ if (r) {
+ pr_err(CONTACT_DRIVER_NAME ": driver registration failed\n");
+ return r;
+ }
- return 0;
-}
+ return 0;
+ }
-static void __exit contact_exit(void)
-{
- mei_cl_driver_unregister(&contact_driver);
-}
+ static void __exit contact_exit(void)
+ {
+ mei_cl_driver_unregister(&contact_driver);
+ }
-module_init(contact_init);
-module_exit(contact_exit);
+ module_init(contact_init);
+ module_exit(contact_exit);
And the driver's simplified probe routine would look like that:
-int contact_probe(struct mei_cl_device *dev, struct mei_cl_device_id *id)
-{
- struct contact_driver *contact;
+.. code-block:: C
- [...]
- mei_cl_enable_device(dev);
+ int contact_probe(struct mei_cl_device *dev, struct mei_cl_device_id *id)
+ {
+ struct contact_driver *contact;
- mei_cl_register_event_cb(dev, contact_event_cb, contact);
+ [...]
+ mei_cl_enable_device(dev);
- return 0;
-}
+ mei_cl_register_event_cb(dev, contact_event_cb, contact);
+
+ return 0;
+ }
In the probe routine the driver first enable the MEI device and then registers
an ME bus event handler which is as close as it can get to registering a
#define MAX_NFC_PAYLOAD 128
-static void contact_event_cb(struct mei_cl_device *dev, u32 events,
- void *context)
-{
- struct contact_driver *contact = context;
+.. code-block:: C
+
+ static void contact_event_cb(struct mei_cl_device *dev, u32 events,
+ void *context)
+ {
+ struct contact_driver *contact = context;
- if (events & BIT(MEI_EVENT_RX)) {
- u8 payload[MAX_NFC_PAYLOAD];
- int payload_size;
+ if (events & BIT(MEI_EVENT_RX)) {
+ u8 payload[MAX_NFC_PAYLOAD];
+ int payload_size;
- payload_size = mei_recv(dev, payload, MAX_NFC_PAYLOAD);
- if (payload_size <= 0)
- return;
+ payload_size = mei_recv(dev, payload, MAX_NFC_PAYLOAD);
+ if (payload_size <= 0)
+ return;
- /* Hook to the NFC subsystem */
- nfc_hci_recv_frame(contact->hdev, payload, payload_size);
+ /* Hook to the NFC subsystem */
+ nfc_hci_recv_frame(contact->hdev, payload, payload_size);
+ }
}
-}
-Intel(R) Management Engine Interface (Intel(R) MEI)
-===================================================
+.. SPDX-License-Identifier: GPL-2.0
Introduction
============
A code snippet for an application communicating with Intel AMTHI client:
+.. code-block:: C
+
struct mei_connect_client_data data;
fd = open(MEI_DEVICE);
close(fd);
-IOCTL
-=====
+IOCTLs
+======
The Intel MEI Driver supports the following IOCTL commands:
IOCTL_MEI_CONNECT_CLIENT Connect to firmware Feature (client).
error returns:
EINVAL Wrong IOCTL Number
- ENODEV Device or Connection is not initialized or ready.
- (e.g. Wrong UUID)
+ ENODEV Device or Connection is not initialized or ready. (e.g. Wrong UUID)
ENOMEM Unable to allocate memory to client internal data.
EFAULT Fatal Error (e.g. Unable to access user input data)
EBUSY Connection Already Open
If the Intel AMT is not enabled in the firmware then the watchdog client won't enumerate
on the me client bus and watchdog devices won't be exposed.
-
Supported Chipsets
==================
+82X38/X48 Express and newer
-7 Series Chipset Family
-6 Series Chipset Family
-5 Series Chipset Family
-4 Series Chipset Family
-Mobile 4 Series Chipset Family
-ICH9
-82946GZ/GL
-82G35 Express
-82Q963/Q965
-82P965/G965
-Mobile PM965/GM965
-Mobile GME965/GLE960
-82Q35 Express
-82G33/G31/P35/P31 Express
-82Q33 Express
-82X38/X48 Express
---
linux-mei@linux.intel.com
projects / users / jedix / linux-maple.git / commitdiff