1 /* SPDX-License-Identifier: GPL-2.0-only */
2 /* Copyright (c) 2018-2021 Intel Corporation */
3
4 #ifndef __LINUX_PECI_H
5 #define __LINUX_PECI_H
6
7 #include <linux/device.h>
8 #include <linux/kernel.h>
9 #include <linux/mutex.h>
10 #include <linux/types.h>
11
12 /*
13 * Currently we don't support any PECI command over 32 bytes.
14 */
15 #define PECI_REQUEST_MAX_BUF_SIZE 32
16
17 struct peci_controller;
18 struct peci_request;
19
20 /**
21 * struct peci_controller_ops - PECI controller specific methods
22 * @xfer: PECI transfer function
23 *
24 * PECI controllers may have different hardware interfaces - the drivers
25 * implementing PECI controllers can use this structure to abstract away those
26 * differences by exposing a common interface for PECI core.
27 */
28 struct peci_controller_ops {
29 int (*xfer)(struct peci_controller *controller, u8 addr, struct peci_request *req);
30 };
31
32 /**
33 * struct peci_controller - PECI controller
34 * @dev: device object to register PECI controller to the device model
35 * @ops: pointer to device specific controller operations
36 * @bus_lock: lock used to protect multiple callers
37 * @id: PECI controller ID
38 *
39 * PECI controllers usually connect to their drivers using non-PECI bus,
40 * such as the platform bus.
41 * Each PECI controller can communicate with one or more PECI devices.
42 */
43 struct peci_controller {
44 struct device dev;
45 const struct peci_controller_ops *ops;
46 struct mutex bus_lock; /* held for the duration of xfer */
47 u8 id;
48 };
49
50 struct peci_controller *devm_peci_controller_add(struct device *parent,
51 const struct peci_controller_ops *ops);
52
53 static inline struct peci_controller *to_peci_controller(void *d)
54 {
55 return container_of(d, struct peci_controller, dev);
56 }
57
58 /**
59 * struct peci_device - PECI device
60 * @dev: device object to register PECI device to the device model
61 * @info: PECI device characteristics
62 * @info.x86_vfm: device vendor-family-model
63 * @info.peci_revision: PECI revision supported by the PECI device
64 * @info.socket_id: the socket ID represented by the PECI device
65 * @addr: address used on the PECI bus connected to the parent controller
66 * @deleted: indicates that PECI device was already deleted
67 *
68 * A peci_device identifies a single device (i.e. CPU) connected to a PECI bus.
69 * The behaviour exposed to the rest of the system is defined by the PECI driver
70 * managing the device.
71 */
72 struct peci_device {
73 struct device dev;
74 struct {
75 u32 x86_vfm;
76 u8 peci_revision;
77 u8 socket_id;
78 } info;
79 u8 addr;
80 bool deleted;
81 };
82
83 static inline struct peci_device *to_peci_device(struct device *d)
84 {
85 return container_of(d, struct peci_device, dev);
86 }
87
88 /**
89 * struct peci_request - PECI request
90 * @device: PECI device to which the request is sent
91 * @tx: TX buffer specific data
92 * @tx.buf: TX buffer
93 * @tx.len: transfer data length in bytes
94 * @rx: RX buffer specific data
95 * @rx.buf: RX buffer
96 * @rx.len: received data length in bytes
97 *
98 * A peci_request represents a request issued by PECI originator (TX) and
99 * a response received from PECI responder (RX).
100 */
101 struct peci_request {
102 struct peci_device *device;
103 struct {
104 u8 buf[PECI_REQUEST_MAX_BUF_SIZE];
105 u8 len;
106 } rx, tx;
107 };
108
109 #endif /* __LINUX_PECI_H */
110
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