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 	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 						 struct peci_controller_ops *ops);
52 
to_peci_controller(void * d)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  * @controller: manages the bus segment hosting this PECI device
62  * @info: PECI device characteristics
63  * @info.family: device family
64  * @info.model: device model
65  * @info.peci_revision: PECI revision supported by the PECI device
66  * @info.socket_id: the socket ID represented by the PECI device
67  * @addr: address used on the PECI bus connected to the parent controller
68  * @deleted: indicates that PECI device was already deleted
69  *
70  * A peci_device identifies a single device (i.e. CPU) connected to a PECI bus.
71  * The behaviour exposed to the rest of the system is defined by the PECI driver
72  * managing the device.
73  */
74 struct peci_device {
75 	struct device dev;
76 	struct {
77 		u16 family;
78 		u8 model;
79 		u8 peci_revision;
80 		u8 socket_id;
81 	} info;
82 	u8 addr;
83 	bool deleted;
84 };
85 
to_peci_device(struct device * d)86 static inline struct peci_device *to_peci_device(struct device *d)
87 {
88 	return container_of(d, struct peci_device, dev);
89 }
90 
91 /**
92  * struct peci_request - PECI request
93  * @device: PECI device to which the request is sent
94  * @tx: TX buffer specific data
95  * @tx.buf: TX buffer
96  * @tx.len: transfer data length in bytes
97  * @rx: RX buffer specific data
98  * @rx.buf: RX buffer
99  * @rx.len: received data length in bytes
100  *
101  * A peci_request represents a request issued by PECI originator (TX) and
102  * a response received from PECI responder (RX).
103  */
104 struct peci_request {
105 	struct peci_device *device;
106 	struct {
107 		u8 buf[PECI_REQUEST_MAX_BUF_SIZE];
108 		u8 len;
109 	} rx, tx;
110 };
111 
112 #endif /* __LINUX_PECI_H */
113