1/*
2 * Remote Processor Framework
3 *
4 * Copyright (C) 2011 Texas Instruments, Inc.
5 * Copyright (C) 2011 Google, Inc.
6 *
7 * Ohad Ben-Cohen <ohad@wizery.com>
8 * Mark Grosen <mgrosen@ti.com>
9 * Brian Swetland <swetland@google.com>
10 * Fernando Guzman Lugo <fernando.lugo@ti.com>
11 * Suman Anna <s-anna@ti.com>
12 * Robert Tivy <rtivy@ti.com>
13 * Armando Uribe De Leon <x0095078@ti.com>
14 *
15 * This program is free software; you can redistribute it and/or
16 * modify it under the terms of the GNU General Public License
17 * version 2 as published by the Free Software Foundation.
18 *
19 * This program is distributed in the hope that it will be useful,
20 * but WITHOUT ANY WARRANTY; without even the implied warranty of
21 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
22 * GNU General Public License for more details.
23 */
24
25#define pr_fmt(fmt)    "%s: " fmt, __func__
26
27#include <linux/kernel.h>
28#include <linux/debugfs.h>
29#include <linux/remoteproc.h>
30#include <linux/device.h>
31
32/* remoteproc debugfs parent dir */
33static struct dentry *rproc_dbg;
34
35/*
36 * Some remote processors may support dumping trace logs into a shared
37 * memory buffer. We expose this trace buffer using debugfs, so users
38 * can easily tell what's going on remotely.
39 *
40 * We will most probably improve the rproc tracing facilities later on,
41 * but this kind of lightweight and simple mechanism is always good to have,
42 * as it provides very early tracing with little to no dependencies at all.
43 */
44static ssize_t rproc_trace_read(struct file *filp, char __user *userbuf,
45						size_t count, loff_t *ppos)
46{
47	struct rproc_mem_entry *trace = filp->private_data;
48	int len = strnlen(trace->va, trace->len);
49
50	return simple_read_from_buffer(userbuf, count, ppos, trace->va, len);
51}
52
53static const struct file_operations trace_rproc_ops = {
54	.read = rproc_trace_read,
55	.open = simple_open,
56	.llseek	= generic_file_llseek,
57};
58
59/*
60 * A state-to-string lookup table, for exposing a human readable state
61 * via debugfs. Always keep in sync with enum rproc_state
62 */
63static const char * const rproc_state_string[] = {
64	"offline",
65	"suspended",
66	"running",
67	"crashed",
68	"invalid",
69};
70
71/* expose the state of the remote processor via debugfs */
72static ssize_t rproc_state_read(struct file *filp, char __user *userbuf,
73						size_t count, loff_t *ppos)
74{
75	struct rproc *rproc = filp->private_data;
76	unsigned int state;
77	char buf[30];
78	int i;
79
80	state = rproc->state > RPROC_LAST ? RPROC_LAST : rproc->state;
81
82	i = snprintf(buf, 30, "%.28s (%d)\n", rproc_state_string[state],
83							rproc->state);
84
85	return simple_read_from_buffer(userbuf, count, ppos, buf, i);
86}
87
88static const struct file_operations rproc_state_ops = {
89	.read = rproc_state_read,
90	.open = simple_open,
91	.llseek	= generic_file_llseek,
92};
93
94/* expose the name of the remote processor via debugfs */
95static ssize_t rproc_name_read(struct file *filp, char __user *userbuf,
96						size_t count, loff_t *ppos)
97{
98	struct rproc *rproc = filp->private_data;
99	/* need room for the name, a newline and a terminating null */
100	char buf[100];
101	int i;
102
103	i = snprintf(buf, sizeof(buf), "%.98s\n", rproc->name);
104
105	return simple_read_from_buffer(userbuf, count, ppos, buf, i);
106}
107
108static const struct file_operations rproc_name_ops = {
109	.read = rproc_name_read,
110	.open = simple_open,
111	.llseek	= generic_file_llseek,
112};
113
114void rproc_remove_trace_file(struct dentry *tfile)
115{
116	debugfs_remove(tfile);
117}
118
119struct dentry *rproc_create_trace_file(const char *name, struct rproc *rproc,
120					struct rproc_mem_entry *trace)
121{
122	struct dentry *tfile;
123
124	tfile = debugfs_create_file(name, 0400, rproc->dbg_dir,
125						trace, &trace_rproc_ops);
126	if (!tfile) {
127		dev_err(rproc->dev, "failed to create debugfs trace entry\n");
128		return NULL;
129	}
130
131	return tfile;
132}
133
134void rproc_delete_debug_dir(struct rproc *rproc)
135{
136	if (!rproc->dbg_dir)
137		return;
138
139	debugfs_remove_recursive(rproc->dbg_dir);
140}
141
142void rproc_create_debug_dir(struct rproc *rproc)
143{
144	struct device *dev = rproc->dev;
145
146	if (!rproc_dbg)
147		return;
148
149	rproc->dbg_dir = debugfs_create_dir(dev_name(dev), rproc_dbg);
150	if (!rproc->dbg_dir)
151		return;
152
153	debugfs_create_file("name", 0400, rproc->dbg_dir,
154					rproc, &rproc_name_ops);
155	debugfs_create_file("state", 0400, rproc->dbg_dir,
156					rproc, &rproc_state_ops);
157}
158
159void __init rproc_init_debugfs(void)
160{
161	if (debugfs_initialized()) {
162		rproc_dbg = debugfs_create_dir(KBUILD_MODNAME, NULL);
163		if (!rproc_dbg)
164			pr_err("can't create debugfs dir\n");
165	}
166}
167
168void __exit rproc_exit_debugfs(void)
169{
170	if (rproc_dbg)
171		debugfs_remove(rproc_dbg);
172}
173