drivers/staging/line6/dumprequest.c

   1 /*
   2  * Line6 Linux USB driver - 0.8.0
   3  *
   4  * Copyright (C) 2004-2009 Markus Grabner (grabner@icg.tugraz.at)
   5  *
   6  *      This program is free software; you can redistribute it and/or
   7  *      modify it under the terms of the GNU General Public License as
   8  *      published by the Free Software Foundation, version 2.
   9  *
  10  */
  11
  12 #include "driver.h"
  13
  14 #include <linux/slab.h>
  15
  16 #include "dumprequest.h"
  17
  18
  19 /*
  20         Set "dump in progress" flag.
  21 */
  22 void line6_dump_started(struct line6_dump_request *l6dr, int dest)
  23 {
  24         l6dr->in_progress = dest;
  25 }
  26
  27 /*
  28         Invalidate current channel, i.e., set "dump in progress" flag.
  29         Reading from the "dump" special file blocks until dump is completed.
  30 */
  31 void line6_invalidate_current(struct line6_dump_request *l6dr)
  32 {
  33         line6_dump_started(l6dr, LINE6_DUMP_CURRENT);
  34 }
  35
  36 /*
  37         Clear "dump in progress" flag and notify waiting processes.
  38 */
  39 void line6_dump_finished(struct line6_dump_request *l6dr)
  40 {
  41         l6dr->in_progress = LINE6_DUMP_NONE;
  42         wake_up_interruptible(&l6dr->wait);
  43 }
  44
  45 /*
  46         Send an asynchronous channel dump request.
  47 */
  48 int line6_dump_request_async(struct line6_dump_request *l6dr,
  49                              struct usb_line6 *line6, int num)
  50 {
  51         int ret;
  52         line6_invalidate_current(l6dr);
  53         ret = line6_send_raw_message_async(line6, l6dr->reqbufs[num].buffer,
  54                                            l6dr->reqbufs[num].length);
  55
  56         if (ret < 0)
  57                 line6_dump_finished(l6dr);
  58
  59         return ret;
  60 }
  61
  62 /*
  63         Send an asynchronous dump request after a given interval.
  64 */
  65 void line6_startup_delayed(struct line6_dump_request *l6dr, int seconds,
  66                            void (*function)(unsigned long), void *data)
  67 {
  68         l6dr->timer.expires = jiffies + seconds * HZ;
  69         l6dr->timer.function = function;
  70         l6dr->timer.data = (unsigned long)data;
  71         add_timer(&l6dr->timer);
  72 }
  73
  74 /*
  75         Wait for completion.
  76 */
  77 int line6_wait_dump(struct line6_dump_request *l6dr, int nonblock)
  78 {
  79         int retval = 0;
  80         DECLARE_WAITQUEUE(wait, current);
  81         add_wait_queue(&l6dr->wait, &wait);
  82         current->state = TASK_INTERRUPTIBLE;
  83
  84         while (l6dr->in_progress) {
  85                 if (nonblock) {
  86                         retval = -EAGAIN;
  87                         break;
  88                 }
  89
  90                 if (signal_pending(current)) {
  91                         retval = -ERESTARTSYS;
  92                         break;
  93                 } else
  94                         schedule();
  95         }
  96
  97         current->state = TASK_RUNNING;
  98         remove_wait_queue(&l6dr->wait, &wait);
  99         return retval;
 100 }
 101
 102 /*
 103         Initialize dump request buffer.
 104 */
 105 int line6_dumpreq_initbuf(struct line6_dump_request *l6dr, const void *buf,
 106                           size_t len, int num)
 107 {
 108         l6dr->reqbufs[num].buffer = kmemdup(buf, len, GFP_KERNEL);
 109         if (l6dr->reqbufs[num].buffer == NULL)
 110                 return -ENOMEM;
 111         l6dr->reqbufs[num].length = len;
 112         return 0;
 113 }
 114
 115 /*
 116         Initialize dump request data structure (including one buffer).
 117 */
 118 int line6_dumpreq_init(struct line6_dump_request *l6dr, const void *buf,
 119                        size_t len)
 120 {
 121         int ret;
 122         ret = line6_dumpreq_initbuf(l6dr, buf, len, 0);
 123         if (ret < 0)
 124                 return ret;
 125         init_waitqueue_head(&l6dr->wait);
 126         init_timer(&l6dr->timer);
 127         return 0;
 128 }
 129
 130 /*
 131         Destruct dump request data structure.
 132 */
 133 void line6_dumpreq_destructbuf(struct line6_dump_request *l6dr, int num)
 134 {
 135         if (l6dr == NULL)
 136                 return;
 137         if (l6dr->reqbufs[num].buffer == NULL)
 138                 return;
 139         kfree(l6dr->reqbufs[num].buffer);
 140         l6dr->reqbufs[num].buffer = NULL;
 141 }
 142
 143 /*
 144         Destruct dump request data structure.
 145 */
 146 void line6_dumpreq_destruct(struct line6_dump_request *l6dr)
 147 {
 148         if (l6dr->reqbufs[0].buffer == NULL)
 149                 return;
 150         line6_dumpreq_destructbuf(l6dr, 0);
 151         l6dr->ok = 1;
 152         del_timer_sync(&l6dr->timer);
 153 }