xref: /openbmc/linux/include/linux/stm.h (revision cc8bbe1a)
1 /*
2  * System Trace Module (STM) infrastructure apis
3  * Copyright (C) 2014 Intel Corporation.
4  *
5  * This program is free software; you can redistribute it and/or modify it
6  * under the terms and conditions of the GNU General Public License,
7  * version 2, as published by the Free Software Foundation.
8  *
9  * This program is distributed in the hope it will be useful, but WITHOUT
10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
12  * more details.
13  */
14 
15 #ifndef _STM_H_
16 #define _STM_H_
17 
18 #include <linux/device.h>
19 
20 /**
21  * enum stp_packet_type - STP packets that an STM driver sends
22  */
23 enum stp_packet_type {
24 	STP_PACKET_DATA = 0,
25 	STP_PACKET_FLAG,
26 	STP_PACKET_USER,
27 	STP_PACKET_MERR,
28 	STP_PACKET_GERR,
29 	STP_PACKET_TRIG,
30 	STP_PACKET_XSYNC,
31 };
32 
33 /**
34  * enum stp_packet_flags - STP packet modifiers
35  */
36 enum stp_packet_flags {
37 	STP_PACKET_MARKED	= 0x1,
38 	STP_PACKET_TIMESTAMPED	= 0x2,
39 };
40 
41 struct stp_policy;
42 
43 struct stm_device;
44 
45 /**
46  * struct stm_data - STM device description and callbacks
47  * @name:		device name
48  * @stm:		internal structure, only used by stm class code
49  * @sw_start:		first STP master available to software
50  * @sw_end:		last STP master available to software
51  * @sw_nchannels:	number of STP channels per master
52  * @sw_mmiosz:		size of one channel's IO space, for mmap, optional
53  * @packet:		callback that sends an STP packet
54  * @mmio_addr:		mmap callback, optional
55  * @link:		called when a new stm_source gets linked to us, optional
56  * @unlink:		likewise for unlinking, again optional
57  * @set_options:	set device-specific options on a channel
58  *
59  * Fill out this structure before calling stm_register_device() to create
60  * an STM device and stm_unregister_device() to destroy it. It will also be
61  * passed back to @packet(), @mmio_addr(), @link(), @unlink() and @set_options()
62  * callbacks.
63  *
64  * Normally, an STM device will have a range of masters available to software
65  * and the rest being statically assigned to various hardware trace sources.
66  * The former is defined by the the range [@sw_start..@sw_end] of the device
67  * description. That is, the lowest master that can be allocated to software
68  * writers is @sw_start and data from this writer will appear is @sw_start
69  * master in the STP stream.
70  */
71 struct stm_data {
72 	const char		*name;
73 	struct stm_device	*stm;
74 	unsigned int		sw_start;
75 	unsigned int		sw_end;
76 	unsigned int		sw_nchannels;
77 	unsigned int		sw_mmiosz;
78 	ssize_t			(*packet)(struct stm_data *, unsigned int,
79 					  unsigned int, unsigned int,
80 					  unsigned int, unsigned int,
81 					  const unsigned char *);
82 	phys_addr_t		(*mmio_addr)(struct stm_data *, unsigned int,
83 					     unsigned int, unsigned int);
84 	int			(*link)(struct stm_data *, unsigned int,
85 					unsigned int);
86 	void			(*unlink)(struct stm_data *, unsigned int,
87 					  unsigned int);
88 	long			(*set_options)(struct stm_data *, unsigned int,
89 					       unsigned int, unsigned int,
90 					       unsigned long);
91 };
92 
93 int stm_register_device(struct device *parent, struct stm_data *stm_data,
94 			struct module *owner);
95 void stm_unregister_device(struct stm_data *stm_data);
96 
97 struct stm_source_device;
98 
99 /**
100  * struct stm_source_data - STM source device description and callbacks
101  * @name:	device name, will be used for policy lookup
102  * @src:	internal structure, only used by stm class code
103  * @nr_chans:	number of channels to allocate
104  * @link:	called when this source gets linked to an STM device
105  * @unlink:	called when this source is about to get unlinked from its STM
106  *
107  * Fill in this structure before calling stm_source_register_device() to
108  * register a source device. Also pass it to unregister and write calls.
109  */
110 struct stm_source_data {
111 	const char		*name;
112 	struct stm_source_device *src;
113 	unsigned int		percpu;
114 	unsigned int		nr_chans;
115 	int			(*link)(struct stm_source_data *data);
116 	void			(*unlink)(struct stm_source_data *data);
117 };
118 
119 int stm_source_register_device(struct device *parent,
120 			       struct stm_source_data *data);
121 void stm_source_unregister_device(struct stm_source_data *data);
122 
123 int stm_source_write(struct stm_source_data *data, unsigned int chan,
124 		     const char *buf, size_t count);
125 
126 #endif /* _STM_H_ */
127