drivers/hid/hid-wiimote-debug.c

   1 /*
   2  * Debug support for HID Nintendo Wiimote devices
   3  * Copyright (c) 2011 David Herrmann
   4  */
   5
   6 /*
   7  * This program is free software; you can redistribute it and/or modify it
   8  * under the terms of the GNU General Public License as published by the Free
   9  * Software Foundation; either version 2 of the License, or (at your option)
  10  * any later version.
  11  */
  12
  13 #include <linux/debugfs.h>
  14 #include <linux/module.h>
  15 #include <linux/spinlock.h>
  16 #include <linux/uaccess.h>
  17 #include "hid-wiimote.h"
  18
  19 struct wiimote_debug {
  20         struct wiimote_data *wdata;
  21         struct dentry *eeprom;
  22 };
  23
  24 static int wiidebug_eeprom_open(struct inode *i, struct file *f)
  25 {
  26         f->private_data = i->i_private;
  27         return 0;
  28 }
  29
  30 static ssize_t wiidebug_eeprom_read(struct file *f, char __user *u, size_t s,
  31                                                                 loff_t *off)
  32 {
  33         struct wiimote_debug *dbg = f->private_data;
  34         struct wiimote_data *wdata = dbg->wdata;
  35         unsigned long flags;
  36         ssize_t ret;
  37         char buf[16];
  38         __u16 size;
  39
  40         if (s == 0)
  41                 return -EINVAL;
  42         if (*off > 0xffffff)
  43                 return 0;
  44         if (s > 16)
  45                 s = 16;
  46
  47         ret = wiimote_cmd_acquire(wdata);
  48         if (ret)
  49                 return ret;
  50
  51         spin_lock_irqsave(&wdata->state.lock, flags);
  52         wdata->state.cmd_read_size = s;
  53         wdata->state.cmd_read_buf = buf;
  54         wiimote_cmd_set(wdata, WIIPROTO_REQ_RMEM, *off & 0xffff);
  55         wiiproto_req_reeprom(wdata, *off, s);
  56         spin_unlock_irqrestore(&wdata->state.lock, flags);
  57
  58         ret = wiimote_cmd_wait(wdata);
  59         if (!ret)
  60                 size = wdata->state.cmd_read_size;
  61
  62         spin_lock_irqsave(&wdata->state.lock, flags);
  63         wdata->state.cmd_read_buf = NULL;
  64         spin_unlock_irqrestore(&wdata->state.lock, flags);
  65
  66         wiimote_cmd_release(wdata);
  67
  68         if (ret)
  69                 return ret;
  70         else if (size == 0)
  71                 return -EIO;
  72
  73         if (copy_to_user(u, buf, size))
  74                 return -EFAULT;
  75
  76         *off += size;
  77         ret = size;
  78
  79         return ret;
  80 }
  81
  82 static const struct file_operations wiidebug_eeprom_fops = {
  83         .owner = THIS_MODULE,
  84         .open = wiidebug_eeprom_open,
  85         .read = wiidebug_eeprom_read,
  86         .llseek = generic_file_llseek,
  87 };
  88
  89 int wiidebug_init(struct wiimote_data *wdata)
  90 {
  91         struct wiimote_debug *dbg;
  92         unsigned long flags;
  93
  94         dbg = kzalloc(sizeof(*dbg), GFP_KERNEL);
  95         if (!dbg)
  96                 return -ENOMEM;
  97
  98         dbg->wdata = wdata;
  99
 100         dbg->eeprom = debugfs_create_file("eeprom", S_IRUSR,
 101                 dbg->wdata->hdev->debug_dir, dbg, &wiidebug_eeprom_fops);
 102         if (!dbg->eeprom) {
 103                 kfree(dbg);
 104                 return -ENOMEM;
 105         }
 106
 107         spin_lock_irqsave(&wdata->state.lock, flags);
 108         wdata->debug = dbg;
 109         spin_unlock_irqrestore(&wdata->state.lock, flags);
 110
 111         return 0;
 112 }
 113
 114 void wiidebug_deinit(struct wiimote_data *wdata)
 115 {
 116         struct wiimote_debug *dbg = wdata->debug;
 117         unsigned long flags;
 118
 119         if (!dbg)
 120                 return;
 121
 122         spin_lock_irqsave(&wdata->state.lock, flags);
 123         wdata->debug = NULL;
 124         spin_unlock_irqrestore(&wdata->state.lock, flags);
 125
 126         debugfs_remove(dbg->eeprom);
 127         kfree(dbg);
 128 }