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authorMaximilian Luz <luzmaximilian@gmail.com>2020-12-21 21:39:58 +0300
committerHans de Goede <hdegoede@redhat.com>2021-01-07 02:06:39 +0300
commit178f6ab77e617c984d6520b92e747075a12676ff (patch)
tree854f50b2ce73d3384dc268be6f5476e42c4b6b73 /include/uapi/linux/surface_aggregator
parent8d7792823da4abd799d63aaceb23805203a5419e (diff)
downloadlinux-178f6ab77e617c984d6520b92e747075a12676ff.tar.xz
platform/surface: Add Surface Aggregator user-space interface
Add a misc-device providing user-space access to the Surface Aggregator EC, mainly intended for debugging, testing, and reverse-engineering. This interface gives user-space applications the ability to send requests to the EC and receive the corresponding responses. The device-file is managed by a pseudo platform-device and corresponding driver to avoid dependence on the dedicated bus, allowing it to be loaded in a minimal configuration. A python library and scripts to access this device can be found at [1]. [1]: https://github.com/linux-surface/surface-aggregator-module/tree/master/scripts/ssam Signed-off-by: Maximilian Luz <luzmaximilian@gmail.com> Link: https://lore.kernel.org/r/20201221183959.1186143-9-luzmaximilian@gmail.com Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Diffstat (limited to 'include/uapi/linux/surface_aggregator')
-rw-r--r--include/uapi/linux/surface_aggregator/cdev.h78
1 files changed, 78 insertions, 0 deletions
diff --git a/include/uapi/linux/surface_aggregator/cdev.h b/include/uapi/linux/surface_aggregator/cdev.h
new file mode 100644
index 000000000000..fbcce04abfe9
--- /dev/null
+++ b/include/uapi/linux/surface_aggregator/cdev.h
@@ -0,0 +1,78 @@
+/* SPDX-License-Identifier: GPL-2.0+ WITH Linux-syscall-note */
+/*
+ * Surface System Aggregator Module (SSAM) user-space EC interface.
+ *
+ * Definitions, structs, and IOCTLs for the /dev/surface/aggregator misc
+ * device. This device provides direct user-space access to the SSAM EC.
+ * Intended for debugging and development.
+ *
+ * Copyright (C) 2020 Maximilian Luz <luzmaximilian@gmail.com>
+ */
+
+#ifndef _UAPI_LINUX_SURFACE_AGGREGATOR_CDEV_H
+#define _UAPI_LINUX_SURFACE_AGGREGATOR_CDEV_H
+
+#include <linux/ioctl.h>
+#include <linux/types.h>
+
+/**
+ * enum ssam_cdev_request_flags - Request flags for SSAM cdev request IOCTL.
+ *
+ * @SSAM_CDEV_REQUEST_HAS_RESPONSE:
+ * Specifies that the request expects a response. If not set, the request
+ * will be directly completed after its underlying packet has been
+ * transmitted. If set, the request transport system waits for a response
+ * of the request.
+ *
+ * @SSAM_CDEV_REQUEST_UNSEQUENCED:
+ * Specifies that the request should be transmitted via an unsequenced
+ * packet. If set, the request must not have a response, meaning that this
+ * flag and the %SSAM_CDEV_REQUEST_HAS_RESPONSE flag are mutually
+ * exclusive.
+ */
+enum ssam_cdev_request_flags {
+ SSAM_CDEV_REQUEST_HAS_RESPONSE = 0x01,
+ SSAM_CDEV_REQUEST_UNSEQUENCED = 0x02,
+};
+
+/**
+ * struct ssam_cdev_request - Controller request IOCTL argument.
+ * @target_category: Target category of the SAM request.
+ * @target_id: Target ID of the SAM request.
+ * @command_id: Command ID of the SAM request.
+ * @instance_id: Instance ID of the SAM request.
+ * @flags: Request flags (see &enum ssam_cdev_request_flags).
+ * @status: Request status (output).
+ * @payload: Request payload (input data).
+ * @payload.data: Pointer to request payload data.
+ * @payload.length: Length of request payload data (in bytes).
+ * @response: Request response (output data).
+ * @response.data: Pointer to response buffer.
+ * @response.length: On input: Capacity of response buffer (in bytes).
+ * On output: Length of request response (number of bytes
+ * in the buffer that are actually used).
+ */
+struct ssam_cdev_request {
+ __u8 target_category;
+ __u8 target_id;
+ __u8 command_id;
+ __u8 instance_id;
+ __u16 flags;
+ __s16 status;
+
+ struct {
+ __u64 data;
+ __u16 length;
+ __u8 __pad[6];
+ } payload;
+
+ struct {
+ __u64 data;
+ __u16 length;
+ __u8 __pad[6];
+ } response;
+} __attribute__((__packed__));
+
+#define SSAM_CDEV_REQUEST _IOWR(0xA5, 1, struct ssam_cdev_request)
+
+#endif /* _UAPI_LINUX_SURFACE_AGGREGATOR_CDEV_H */