1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * OSS compatible sequencer driver
4 *
5 * Timer control routines
6 *
7 * Copyright (C) 1998,99 Takashi Iwai <tiwai@suse.de>
8 */
9
10#include "seq_oss_timer.h"
11#include "seq_oss_event.h"
12#include <sound/seq_oss_legacy.h>
13#include <linux/slab.h>
14
15/*
16 */
17#define MIN_OSS_TEMPO 8
18#define MAX_OSS_TEMPO 360
19#define MIN_OSS_TIMEBASE 1
20#define MAX_OSS_TIMEBASE 1000
21
22/*
23 */
24static void calc_alsa_tempo(struct seq_oss_timer *timer);
25static int send_timer_event(struct seq_oss_devinfo *dp, int type, int value);
26
27
28/*
29 * create and register a new timer.
30 * if queue is not started yet, start it.
31 */
32struct seq_oss_timer *
33snd_seq_oss_timer_new(struct seq_oss_devinfo *dp)
34{
35 struct seq_oss_timer *rec;
36
37 rec = kzalloc(sizeof(*rec), GFP_KERNEL);
38 if (rec == NULL)
39 return NULL;
40
41 rec->dp = dp;
42 rec->cur_tick = 0;
43 rec->realtime = 0;
44 rec->running = 0;
45 rec->oss_tempo = 60;
46 rec->oss_timebase = 100;
47 calc_alsa_tempo(timer: rec);
48
49 return rec;
50}
51
52
53/*
54 * delete timer.
55 * if no more timer exists, stop the queue.
56 */
57void
58snd_seq_oss_timer_delete(struct seq_oss_timer *rec)
59{
60 if (rec) {
61 snd_seq_oss_timer_stop(timer: rec);
62 kfree(objp: rec);
63 }
64}
65
66
67/*
68 * process one timing event
69 * return 1 : event proceseed -- skip this event
70 * 0 : not a timer event -- enqueue this event
71 */
72int
73snd_seq_oss_process_timer_event(struct seq_oss_timer *rec, union evrec *ev)
74{
75 abstime_t parm = ev->t.time;
76
77 if (ev->t.code == EV_TIMING) {
78 switch (ev->t.cmd) {
79 case TMR_WAIT_REL:
80 parm += rec->cur_tick;
81 rec->realtime = 0;
82 fallthrough;
83 case TMR_WAIT_ABS:
84 if (parm == 0) {
85 rec->realtime = 1;
86 } else if (parm >= rec->cur_tick) {
87 rec->realtime = 0;
88 rec->cur_tick = parm;
89 }
90 return 1; /* skip this event */
91
92 case TMR_START:
93 snd_seq_oss_timer_start(timer: rec);
94 return 1;
95
96 }
97 } else if (ev->s.code == SEQ_WAIT) {
98 /* time = from 1 to 3 bytes */
99 parm = (ev->echo >> 8) & 0xffffff;
100 if (parm > rec->cur_tick) {
101 /* set next event time */
102 rec->cur_tick = parm;
103 rec->realtime = 0;
104 }
105 return 1;
106 }
107
108 return 0;
109}
110
111
112/*
113 * convert tempo units
114 */
115static void
116calc_alsa_tempo(struct seq_oss_timer *timer)
117{
118 timer->tempo = (60 * 1000000) / timer->oss_tempo;
119 timer->ppq = timer->oss_timebase;
120}
121
122
123/*
124 * dispatch a timer event
125 */
126static int
127send_timer_event(struct seq_oss_devinfo *dp, int type, int value)
128{
129 struct snd_seq_event ev;
130
131 memset(&ev, 0, sizeof(ev));
132 ev.type = type;
133 ev.source.client = dp->cseq;
134 ev.source.port = 0;
135 ev.dest.client = SNDRV_SEQ_CLIENT_SYSTEM;
136 ev.dest.port = SNDRV_SEQ_PORT_SYSTEM_TIMER;
137 ev.queue = dp->queue;
138 ev.data.queue.queue = dp->queue;
139 ev.data.queue.param.value = value;
140 return snd_seq_kernel_client_dispatch(client: dp->cseq, ev: &ev, atomic: 1, hop: 0);
141}
142
143/*
144 * set queue tempo and start queue
145 */
146int
147snd_seq_oss_timer_start(struct seq_oss_timer *timer)
148{
149 struct seq_oss_devinfo *dp = timer->dp;
150 struct snd_seq_queue_tempo tmprec;
151
152 if (timer->running)
153 snd_seq_oss_timer_stop(timer);
154
155 memset(&tmprec, 0, sizeof(tmprec));
156 tmprec.queue = dp->queue;
157 tmprec.ppq = timer->ppq;
158 tmprec.tempo = timer->tempo;
159 snd_seq_set_queue_tempo(client: dp->cseq, tempo: &tmprec);
160
161 send_timer_event(dp, SNDRV_SEQ_EVENT_START, value: 0);
162 timer->running = 1;
163 timer->cur_tick = 0;
164 return 0;
165}
166
167
168/*
169 * stop queue
170 */
171int
172snd_seq_oss_timer_stop(struct seq_oss_timer *timer)
173{
174 if (! timer->running)
175 return 0;
176 send_timer_event(dp: timer->dp, SNDRV_SEQ_EVENT_STOP, value: 0);
177 timer->running = 0;
178 return 0;
179}
180
181
182/*
183 * continue queue
184 */
185int
186snd_seq_oss_timer_continue(struct seq_oss_timer *timer)
187{
188 if (timer->running)
189 return 0;
190 send_timer_event(dp: timer->dp, SNDRV_SEQ_EVENT_CONTINUE, value: 0);
191 timer->running = 1;
192 return 0;
193}
194
195
196/*
197 * change queue tempo
198 */
199int
200snd_seq_oss_timer_tempo(struct seq_oss_timer *timer, int value)
201{
202 if (value < MIN_OSS_TEMPO)
203 value = MIN_OSS_TEMPO;
204 else if (value > MAX_OSS_TEMPO)
205 value = MAX_OSS_TEMPO;
206 timer->oss_tempo = value;
207 calc_alsa_tempo(timer);
208 if (timer->running)
209 send_timer_event(dp: timer->dp, SNDRV_SEQ_EVENT_TEMPO, value: timer->tempo);
210 return 0;
211}
212
213
214/*
215 * ioctls
216 */
217int
218snd_seq_oss_timer_ioctl(struct seq_oss_timer *timer, unsigned int cmd, int __user *arg)
219{
220 int value;
221
222 if (cmd == SNDCTL_SEQ_CTRLRATE) {
223 /* if *arg == 0, just return the current rate */
224 if (get_user(value, arg))
225 return -EFAULT;
226 if (value)
227 return -EINVAL;
228 value = ((timer->oss_tempo * timer->oss_timebase) + 30) / 60;
229 return put_user(value, arg) ? -EFAULT : 0;
230 }
231
232 if (timer->dp->seq_mode == SNDRV_SEQ_OSS_MODE_SYNTH)
233 return 0;
234
235 switch (cmd) {
236 case SNDCTL_TMR_START:
237 return snd_seq_oss_timer_start(timer);
238 case SNDCTL_TMR_STOP:
239 return snd_seq_oss_timer_stop(timer);
240 case SNDCTL_TMR_CONTINUE:
241 return snd_seq_oss_timer_continue(timer);
242 case SNDCTL_TMR_TEMPO:
243 if (get_user(value, arg))
244 return -EFAULT;
245 return snd_seq_oss_timer_tempo(timer, value);
246 case SNDCTL_TMR_TIMEBASE:
247 if (get_user(value, arg))
248 return -EFAULT;
249 if (value < MIN_OSS_TIMEBASE)
250 value = MIN_OSS_TIMEBASE;
251 else if (value > MAX_OSS_TIMEBASE)
252 value = MAX_OSS_TIMEBASE;
253 timer->oss_timebase = value;
254 calc_alsa_tempo(timer);
255 return 0;
256
257 case SNDCTL_TMR_METRONOME:
258 case SNDCTL_TMR_SELECT:
259 case SNDCTL_TMR_SOURCE:
260 /* not supported */
261 return 0;
262 }
263 return 0;
264}
265

source code of linux/sound/core/seq/oss/seq_oss_timer.c