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 <linux/time.h> 29 #include <sound/core.h> 30 #include <sound/emu10k1.h> 31 32 static int snd_emu10k1_timer_start(struct snd_timer *timer) 33 { 34 struct snd_emu10k1 *emu; 35 unsigned long flags; 36 unsigned int delay; 37 38 emu = snd_timer_chip(timer); 39 delay = timer->sticks - 1; 40 if (delay < 5 ) /* minimum time is 5 ticks */ 41 delay = 5; 42 spin_lock_irqsave(&emu->reg_lock, flags); 43 snd_emu10k1_intr_enable(emu, INTE_INTERVALTIMERENB); 44 outw(delay & TIMER_RATE_MASK, emu->port + TIMER); 45 spin_unlock_irqrestore(&emu->reg_lock, flags); 46 return 0; 47 } 48 49 static int snd_emu10k1_timer_stop(struct snd_timer *timer) 50 { 51 struct snd_emu10k1 *emu; 52 unsigned long flags; 53 54 emu = snd_timer_chip(timer); 55 spin_lock_irqsave(&emu->reg_lock, flags); 56 snd_emu10k1_intr_disable(emu, INTE_INTERVALTIMERENB); 57 spin_unlock_irqrestore(&emu->reg_lock, flags); 58 return 0; 59 } 60 61 static int snd_emu10k1_timer_precise_resolution(struct snd_timer *timer, 62 unsigned long *num, unsigned long *den) 63 { 64 *num = 1; 65 *den = 48000; 66 return 0; 67 } 68 69 static struct snd_timer_hardware snd_emu10k1_timer_hw = { 70 .flags = SNDRV_TIMER_HW_AUTO, 71 .resolution = 20833, /* 1 sample @ 48KHZ = 20.833...us */ 72 .ticks = 1024, 73 .start = snd_emu10k1_timer_start, 74 .stop = snd_emu10k1_timer_stop, 75 .precise_resolution = snd_emu10k1_timer_precise_resolution, 76 }; 77 78 int snd_emu10k1_timer(struct snd_emu10k1 *emu, int device) 79 { 80 struct snd_timer *timer = NULL; 81 struct snd_timer_id tid; 82 int err; 83 84 tid.dev_class = SNDRV_TIMER_CLASS_CARD; 85 tid.dev_sclass = SNDRV_TIMER_SCLASS_NONE; 86 tid.card = emu->card->number; 87 tid.device = device; 88 tid.subdevice = 0; 89 if ((err = snd_timer_new(emu->card, "EMU10K1", &tid, &timer)) >= 0) { 90 strcpy(timer->name, "EMU10K1 timer"); 91 timer->private_data = emu; 92 timer->hw = snd_emu10k1_timer_hw; 93 } 94 emu->timer = timer; 95 return err; 96 } 97