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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  */
24 static void calc_alsa_tempo(struct seq_oss_timer *timer);
25 static 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  */
32 struct seq_oss_timer *
snd_seq_oss_timer_new(struct seq_oss_devinfo * dp)33 snd_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(rec);
48 
49 	return rec;
50 }
51 
52 
53 /*
54  * delete timer.
55  * if no more timer exists, stop the queue.
56  */
57 void
snd_seq_oss_timer_delete(struct seq_oss_timer * rec)58 snd_seq_oss_timer_delete(struct seq_oss_timer *rec)
59 {
60 	if (rec) {
61 		snd_seq_oss_timer_stop(rec);
62 		kfree(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  */
72 int
snd_seq_oss_process_timer_event(struct seq_oss_timer * rec,union evrec * ev)73 snd_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 			/* fall through */
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(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  */
115 static void
calc_alsa_tempo(struct seq_oss_timer * timer)116 calc_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  */
126 static int
send_timer_event(struct seq_oss_devinfo * dp,int type,int value)127 send_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(dp->cseq, &ev, 1, 0);
141 }
142 
143 /*
144  * set queue tempo and start queue
145  */
146 int
snd_seq_oss_timer_start(struct seq_oss_timer * timer)147 snd_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(dp->cseq, &tmprec);
160 
161 	send_timer_event(dp, SNDRV_SEQ_EVENT_START, 0);
162 	timer->running = 1;
163 	timer->cur_tick = 0;
164 	return 0;
165 }
166 
167 
168 /*
169  * stop queue
170  */
171 int
snd_seq_oss_timer_stop(struct seq_oss_timer * timer)172 snd_seq_oss_timer_stop(struct seq_oss_timer *timer)
173 {
174 	if (! timer->running)
175 		return 0;
176 	send_timer_event(timer->dp, SNDRV_SEQ_EVENT_STOP, 0);
177 	timer->running = 0;
178 	return 0;
179 }
180 
181 
182 /*
183  * continue queue
184  */
185 int
snd_seq_oss_timer_continue(struct seq_oss_timer * timer)186 snd_seq_oss_timer_continue(struct seq_oss_timer *timer)
187 {
188 	if (timer->running)
189 		return 0;
190 	send_timer_event(timer->dp, SNDRV_SEQ_EVENT_CONTINUE, 0);
191 	timer->running = 1;
192 	return 0;
193 }
194 
195 
196 /*
197  * change queue tempo
198  */
199 int
snd_seq_oss_timer_tempo(struct seq_oss_timer * timer,int value)200 snd_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(timer->dp, SNDRV_SEQ_EVENT_TEMPO, timer->tempo);
210 	return 0;
211 }
212 
213 
214 /*
215  * ioctls
216  */
217 int
snd_seq_oss_timer_ioctl(struct seq_oss_timer * timer,unsigned int cmd,int __user * arg)218 snd_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