Merge branch 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux...
[linux-2.6-microblaze.git] / drivers / hwtracing / stm / dummy_stm.c
1 /*
2  * A dummy STM device for stm/stm_source class testing.
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  * STM class implements generic infrastructure for  System Trace Module devices
15  * as defined in MIPI STPv2 specification.
16  */
17
18 #undef DEBUG
19 #include <linux/kernel.h>
20 #include <linux/module.h>
21 #include <linux/slab.h>
22 #include <linux/stm.h>
23
24 static ssize_t notrace
25 dummy_stm_packet(struct stm_data *stm_data, unsigned int master,
26                  unsigned int channel, unsigned int packet, unsigned int flags,
27                  unsigned int size, const unsigned char *payload)
28 {
29 #ifdef DEBUG
30         u64 pl = 0;
31
32         if (payload)
33                 pl = *(u64 *)payload;
34
35         if (size < 8)
36                 pl &= (1ull << (size * 8)) - 1;
37         trace_printk("[%u:%u] [pkt: %x/%x] (%llx)\n", master, channel,
38                      packet, size, pl);
39 #endif
40         return size;
41 }
42
43 #define DUMMY_STM_MAX 32
44
45 static struct stm_data dummy_stm[DUMMY_STM_MAX];
46
47 static int nr_dummies = 4;
48
49 module_param(nr_dummies, int, 0400);
50
51 static unsigned int fail_mode;
52
53 module_param(fail_mode, int, 0600);
54
55 static int dummy_stm_link(struct stm_data *data, unsigned int master,
56                           unsigned int channel)
57 {
58         if (fail_mode && (channel & fail_mode))
59                 return -EINVAL;
60
61         return 0;
62 }
63
64 static int dummy_stm_init(void)
65 {
66         int i, ret = -ENOMEM;
67
68         if (nr_dummies < 0 || nr_dummies > DUMMY_STM_MAX)
69                 return -EINVAL;
70
71         for (i = 0; i < nr_dummies; i++) {
72                 dummy_stm[i].name = kasprintf(GFP_KERNEL, "dummy_stm.%d", i);
73                 if (!dummy_stm[i].name)
74                         goto fail_unregister;
75
76                 dummy_stm[i].sw_start           = 0x0000;
77                 dummy_stm[i].sw_end             = 0xffff;
78                 dummy_stm[i].sw_nchannels       = 0xffff;
79                 dummy_stm[i].packet             = dummy_stm_packet;
80                 dummy_stm[i].link               = dummy_stm_link;
81
82                 ret = stm_register_device(NULL, &dummy_stm[i], THIS_MODULE);
83                 if (ret)
84                         goto fail_free;
85         }
86
87         return 0;
88
89 fail_unregister:
90         for (i--; i >= 0; i--) {
91                 stm_unregister_device(&dummy_stm[i]);
92 fail_free:
93                 kfree(dummy_stm[i].name);
94         }
95
96         return ret;
97
98 }
99
100 static void dummy_stm_exit(void)
101 {
102         int i;
103
104         for (i = 0; i < nr_dummies; i++) {
105                 stm_unregister_device(&dummy_stm[i]);
106                 kfree(dummy_stm[i].name);
107         }
108 }
109
110 module_init(dummy_stm_init);
111 module_exit(dummy_stm_exit);
112
113 MODULE_LICENSE("GPL v2");
114 MODULE_DESCRIPTION("dummy_stm device");
115 MODULE_AUTHOR("Alexander Shishkin <alexander.shishkin@linux.intel.com>");