projects / linux-2.6-block.git / blame
| Commit | Line | Data |
|---|---|---|
| 262e1f6e CZ |
1 | /* |
| 2 | * Simple kernel driver to link kernel Ftrace and an STM device | |
| 3 | * Copyright (c) 2016, Linaro Ltd. | |
| 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 Ftrace will be registered as a trace_export. | |
| 15 | */ | |
| 16 | ||
| 17 | #include <linux/module.h> | |
| 18 | #include <linux/stm.h> | |
| 19 | #include <linux/trace.h> | |
| 20 | ||
| 21 | #define STM_FTRACE_NR_CHANNELS 1 | |
| 22 | #define STM_FTRACE_CHAN 0 | |
| 23 | ||
| 24 | static int stm_ftrace_link(struct stm_source_data *data); | |
| 25 | static void stm_ftrace_unlink(struct stm_source_data *data); | |
| 26 | ||
| 27 | static struct stm_ftrace { | |
| 28 | struct stm_source_data data; | |
| 29 | struct trace_export ftrace; | |
| 30 | } stm_ftrace = { | |
| 31 | .data = { | |
| 32 | .name = "ftrace", | |
| 33 | .nr_chans = STM_FTRACE_NR_CHANNELS, | |
| 34 | .link = stm_ftrace_link, | |
| 35 | .unlink = stm_ftrace_unlink, | |
| 36 | }, | |
| 37 | }; | |
| 38 | ||
| 39 | /** | |
| 40 | * stm_ftrace_write() - write data to STM via 'stm_ftrace' source | |
| 41 | * @buf: buffer containing the data packet | |
| 42 | * @len: length of the data packet | |
| 43 | */ | |
| 44 | static void notrace | |
| a773d419 | 45 | stm_ftrace_write(struct trace_export *export, const void *buf, unsigned int len) |
| 262e1f6e | 46 | { |
| a773d419 FB |
47 | struct stm_ftrace *stm = container_of(export, struct stm_ftrace, ftrace); |
| 48 | ||
| 49 | stm_source_write(&stm->data, STM_FTRACE_CHAN, buf, len); | |
| 262e1f6e CZ |
50 | } |
| 51 | ||
| 52 | static int stm_ftrace_link(struct stm_source_data *data) | |
| 53 | { | |
| 54 | struct stm_ftrace *sf = container_of(data, struct stm_ftrace, data); | |
| 55 | ||
| 56 | sf->ftrace.write = stm_ftrace_write; | |
| 57 | ||
| 58 | return register_ftrace_export(&sf->ftrace); | |
| 59 | } | |
| 60 | ||
| 61 | static void stm_ftrace_unlink(struct stm_source_data *data) | |
| 62 | { | |
| 63 | struct stm_ftrace *sf = container_of(data, struct stm_ftrace, data); | |
| 64 | ||
| 65 | unregister_ftrace_export(&sf->ftrace); | |
| 66 | } | |
| 67 | ||
| 68 | static int __init stm_ftrace_init(void) | |
| 69 | { | |
| 70 | int ret; | |
| 71 | ||
| 72 | ret = stm_source_register_device(NULL, &stm_ftrace.data); | |
| 73 | if (ret) | |
| 74 | pr_err("Failed to register stm_source - ftrace.\n"); | |
| 75 | ||
| 76 | return ret; | |
| 77 | } | |
| 78 | ||
| 79 | static void __exit stm_ftrace_exit(void) | |
| 80 | { | |
| 81 | stm_source_unregister_device(&stm_ftrace.data); | |
| 82 | } | |
| 83 | ||
| 84 | module_init(stm_ftrace_init); | |
| 85 | module_exit(stm_ftrace_exit); | |
| 86 | ||
| 87 | MODULE_LICENSE("GPL v2"); | |
| 88 | MODULE_DESCRIPTION("stm_ftrace driver"); | |
| 89 | MODULE_AUTHOR("Chunyan Zhang <zhang.chunyan@linaro.org>"); |