drivers/remoteproc/remoteproc_debugfs.c

   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 */
  33 static 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  */
  44 static 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
  53 static int rproc_open_generic(struct inode *inode, struct file *file)
  54 {
  55         file->private_data = inode->i_private;
  56
  57         return 0;
  58 }
  59
  60 static const struct file_operations trace_rproc_ops = {
  61         .read = rproc_trace_read,
  62         .open = rproc_open_generic,
  63         .llseek = generic_file_llseek,
  64 };
  65
  66 /*
  67  * A state-to-string lookup table, for exposing a human readable state
  68  * via debugfs. Always keep in sync with enum rproc_state
  69  */
  70 static const char * const rproc_state_string[] = {
  71         "offline",
  72         "suspended",
  73         "running",
  74         "crashed",
  75         "invalid",
  76 };
  77
  78 /* expose the state of the remote processor via debugfs */
  79 static ssize_t rproc_state_read(struct file *filp, char __user *userbuf,
  80                                                 size_t count, loff_t *ppos)
  81 {
  82         struct rproc *rproc = filp->private_data;
  83         unsigned int state;
  84         char buf[30];
  85         int i;
  86
  87         state = rproc->state > RPROC_LAST ? RPROC_LAST : rproc->state;
  88
  89         i = snprintf(buf, 30, "%.28s (%d)\n", rproc_state_string[state],
  90                                                         rproc->state);
  91
  92         return simple_read_from_buffer(userbuf, count, ppos, buf, i);
  93 }
  94
  95 static const struct file_operations rproc_state_ops = {
  96         .read = rproc_state_read,
  97         .open = rproc_open_generic,
  98         .llseek = generic_file_llseek,
  99 };
 100
 101 /* expose the name of the remote processor via debugfs */
 102 static ssize_t rproc_name_read(struct file *filp, char __user *userbuf,
 103                                                 size_t count, loff_t *ppos)
 104 {
 105         struct rproc *rproc = filp->private_data;
 106         /* need room for the name, a newline and a terminating null */
 107         char buf[100];
 108         int i;
 109
 110         i = snprintf(buf, sizeof(buf), "%.98s\n", rproc->name);
 111
 112         return simple_read_from_buffer(userbuf, count, ppos, buf, i);
 113 }
 114
 115 static const struct file_operations rproc_name_ops = {
 116         .read = rproc_name_read,
 117         .open = rproc_open_generic,
 118         .llseek = generic_file_llseek,
 119 };
 120
 121 void rproc_remove_trace_file(struct dentry *tfile)
 122 {
 123         debugfs_remove(tfile);
 124 }
 125
 126 struct dentry *rproc_create_trace_file(const char *name, struct rproc *rproc,
 127                                         struct rproc_mem_entry *trace)
 128 {
 129         struct dentry *tfile;
 130
 131         tfile = debugfs_create_file(name, 0400, rproc->dbg_dir,
 132                                                 trace, &trace_rproc_ops);
 133         if (!tfile) {
 134                 dev_err(rproc->dev, "failed to create debugfs trace entry\n");
 135                 return NULL;
 136         }
 137
 138         return tfile;
 139 }
 140
 141 void rproc_delete_debug_dir(struct rproc *rproc)
 142 {
 143         if (!rproc->dbg_dir)
 144                 return;
 145
 146         debugfs_remove_recursive(rproc->dbg_dir);
 147 }
 148
 149 void rproc_create_debug_dir(struct rproc *rproc)
 150 {
 151         struct device *dev = rproc->dev;
 152
 153         if (!rproc_dbg)
 154                 return;
 155
 156         rproc->dbg_dir = debugfs_create_dir(dev_name(dev), rproc_dbg);
 157         if (!rproc->dbg_dir)
 158                 return;
 159
 160         debugfs_create_file("name", 0400, rproc->dbg_dir,
 161                                         rproc, &rproc_name_ops);
 162         debugfs_create_file("state", 0400, rproc->dbg_dir,
 163                                         rproc, &rproc_state_ops);
 164 }
 165
 166 void __init rproc_init_debugfs(void)
 167 {
 168         if (debugfs_initialized()) {
 169                 rproc_dbg = debugfs_create_dir(KBUILD_MODNAME, NULL);
 170                 if (!rproc_dbg)
 171                         pr_err("can't create debugfs dir\n");
 172         }
 173 }
 174
 175 void __exit rproc_exit_debugfs(void)
 176 {
 177         if (rproc_dbg)
 178                 debugfs_remove(rproc_dbg);
 179 }