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