sound/pci/emu10k1/timer.c

   1 /*
   2  *  Copyright (c) by Lee Revell <rlrevell@joe-job.com>
   3  *                   Clemens Ladisch <clemens@ladisch.de>
   4  *  Routines for control of EMU10K1 chips
   5  *
   6  *  BUGS:
   7  *    --
   8  *
   9  *  TODO:
  10  *    --
  11  *
  12  *   This program is free software; you can redistribute it and/or modify
  13  *   it under the terms of the GNU General Public License as published by
  14  *   the Free Software Foundation; either version 2 of the License, or
  15  *   (at your option) any later version.
  16  *
  17  *   This program is distributed in the hope that it will be useful,
  18  *   but WITHOUT ANY WARRANTY; without even the implied warranty of
  19  *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  20  *   GNU General Public License for more details.
  21  *
  22  *   You should have received a copy of the GNU General Public License
  23  *   along with this program; if not, write to the Free Software
  24  *   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
  25  *
  26  */
  27
  28 #include <sound/driver.h>
  29 #include <linux/time.h>
  30 #include <sound/core.h>
  31 #include <sound/emu10k1.h>
  32
  33 static int snd_emu10k1_timer_start(struct snd_timer *timer)
  34 {
  35         struct snd_emu10k1 *emu;
  36         unsigned long flags;
  37         unsigned int delay;
  38
  39         emu = snd_timer_chip(timer);
  40         delay = timer->sticks - 1;
  41         if (delay < 5 ) /* minimum time is 5 ticks */
  42                 delay = 5;
  43         spin_lock_irqsave(&emu->reg_lock, flags);
  44         snd_emu10k1_intr_enable(emu, INTE_INTERVALTIMERENB);
  45         outw(delay & TIMER_RATE_MASK, emu->port + TIMER);
  46         spin_unlock_irqrestore(&emu->reg_lock, flags);
  47         return 0;
  48 }
  49
  50 static int snd_emu10k1_timer_stop(struct snd_timer *timer)
  51 {
  52         struct snd_emu10k1 *emu;
  53         unsigned long flags;
  54
  55         emu = snd_timer_chip(timer);
  56         spin_lock_irqsave(&emu->reg_lock, flags);
  57         snd_emu10k1_intr_disable(emu, INTE_INTERVALTIMERENB);
  58         spin_unlock_irqrestore(&emu->reg_lock, flags);
  59         return 0;
  60 }
  61
  62 static int snd_emu10k1_timer_precise_resolution(struct snd_timer *timer,
  63                                                unsigned long *num, unsigned long *den)
  64 {
  65         *num = 1;
  66         *den = 48000;
  67         return 0;
  68 }
  69
  70 static struct snd_timer_hardware snd_emu10k1_timer_hw = {
  71         .flags = SNDRV_TIMER_HW_AUTO,
  72         .resolution = 20833, /* 1 sample @ 48KHZ = 20.833...us */
  73         .ticks = 1024,
  74         .start = snd_emu10k1_timer_start,
  75         .stop = snd_emu10k1_timer_stop,
  76         .precise_resolution = snd_emu10k1_timer_precise_resolution,
  77 };
  78
  79 int __devinit snd_emu10k1_timer(struct snd_emu10k1 *emu, int device)
  80 {
  81         struct snd_timer *timer = NULL;
  82         struct snd_timer_id tid;
  83         int err;
  84
  85         tid.dev_class = SNDRV_TIMER_CLASS_CARD;
  86         tid.dev_sclass = SNDRV_TIMER_SCLASS_NONE;
  87         tid.card = emu->card->number;
  88         tid.device = device;
  89         tid.subdevice = 0;
  90         if ((err = snd_timer_new(emu->card, "EMU10K1", &tid, &timer)) >= 0) {
  91                 strcpy(timer->name, "EMU10K1 timer");
  92                 timer->private_data = emu;
  93                 timer->hw = snd_emu10k1_timer_hw;
  94         }
  95         emu->timer = timer;
  96         return err;
  97 }