aboutsummaryrefslogtreecommitdiffstats
path: root/sound/oss/sh_dac_audio.c
blob: 479e3025a8a367bb7ea0cc01ae13107b9a634fa9 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
/*
 * sound/oss/sh_dac_audio.c
 *
 * SH DAC based sound :(
 *
 *  Copyright (C) 2004,2005  Andriy Skulysh
 *
 * This file is subject to the terms and conditions of the GNU General Public
 * License.  See the file "COPYING" in the main directory of this archive
 * for more details.
 */
#include <linux/module.h>
#include <linux/init.h>
#include <linux/sched.h>
#include <linux/linkage.h>
#include <linux/slab.h>
#include <linux/fs.h>
#include <linux/sound.h>
#include <linux/smp_lock.h>
#include <linux/soundcard.h>
#include <linux/interrupt.h>
#include <linux/hrtimer.h>
#include <asm/io.h>
#include <asm/uaccess.h>
#include <asm/irq.h>
#include <asm/delay.h>
#include <asm/clock.h>
#include <cpu/dac.h>
#include <asm/machvec.h>
#include <mach/hp6xx.h>
#include <asm/hd64461.h>

#define MODNAME "sh_dac_audio"

#define BUFFER_SIZE 48000

static int rate;
static int empty;
static char *data_buffer, *buffer_begin, *buffer_end;
static int in_use, device_major;
static struct hrtimer hrtimer;
static ktime_t wakeups_per_second;

static void dac_audio_start_timer(void)
{
	hrtimer_start(&hrtimer, wakeups_per_second, HRTIMER_MODE_REL);
}

static void dac_audio_stop_timer(void)
{
	hrtimer_cancel(&hrtimer);
}

static void dac_audio_reset(void)
{
	dac_audio_stop_timer();
	buffer_begin = buffer_end = data_buffer;
	empty = 1;
}

static void dac_audio_sync(void)
{
	while (!empty)
		schedule();
}

static void dac_audio_start(void)
{
	if (mach_is_hp6xx()) {
		u16 v = __raw_readw(HD64461_GPADR);
		v &= ~HD64461_GPADR_SPEAKER;
		__raw_writew(v, HD64461_GPADR);
	}

	sh_dac_enable(CONFIG_SOUND_SH_DAC_AUDIO_CHANNEL);
}
static void dac_audio_stop(void)
{
	dac_audio_stop_timer();

	if (mach_is_hp6xx()) {
		u16 v = __raw_readw(HD64461_GPADR);
		v |= HD64461_GPADR_SPEAKER;
		__raw_writew(v, HD64461_GPADR);
	}

	sh_dac_output(0, CONFIG_SOUND_SH_DAC_AUDIO_CHANNEL);
	sh_dac_disable(CONFIG_SOUND_SH_DAC_AUDIO_CHANNEL);
}

static void dac_audio_set_rate(void)
{
	wakeups_per_second = ktime_set(0, 1000000000 / rate);
}

static int dac_audio_ioctl(struct file *file,
			   unsigned int cmd, unsigned long arg)
{
	int val;

	switch (cmd) {
	case OSS_GETVERSION:
		return put_user(SOUND_VERSION, (int *)arg);

	case SNDCTL_DSP_SYNC:
		dac_audio_sync();
		return 0;

	case SNDCTL_DSP_RESET:
		dac_audio_reset();
		return 0;

	case SNDCTL_DSP_GETFMTS:
		return put_user(AFMT_U8, (int *)arg);

	case SNDCTL_DSP_SETFMT:
		return put_user(AFMT_U8, (int *)arg);

	case SNDCTL_DSP_NONBLOCK:
		spin_lock(&file->f_lock);
		file->f_flags |= O_NONBLOCK;
		spin_unlock(&file->f_lock);
		return 0;

	case SNDCTL_DSP_GETCAPS:
		return 0;

	case SOUND_PCM_WRITE_RATE:
		val = *(int *)arg;
		if (val > 0) {
			rate = val;
			dac_audio_set_rate();
		}
		return put_user(rate, (int *)arg);

	case SNDCTL_DSP_STEREO:
		return put_user(0, (int *)arg);

	case SOUND_PCM_WRITE_CHANNELS:
		return put_user(1, (int *)arg);

	case SNDCTL_DSP_SETDUPLEX:
		return -EINVAL;

	case SNDCTL_DSP_PROFILE:
		return -EINVAL;

	case SNDCTL_DSP_GETBLKSIZE:
		return put_user(BUFFER_SIZE, (int *)arg);

	case SNDCTL_DSP_SETFRAGMENT:
		return 0;

	default:
		printk(KERN_ERR "sh_dac_audio: unimplemented ioctl=0x%x\n",
		       cmd);
		return -EINVAL;
	}
	return -EINVAL;
}

static long dac_audio_unlocked_ioctl(struct file *file, u_int cmd, u_long arg)
{
	int ret;

	lock_kernel();
	ret = dac_audio_ioctl(file, cmd, arg);
	unlock_kernel();

	return ret;
}

static ssize_t dac_audio_write(struct file *file, const char *buf, size_t count,
			       loff_t * ppos)
{
	int free;
	int nbytes;

	if (!count) {
		dac_audio_sync();
		return 0;
	}

	free = buffer_begin - buffer_end;

	if (free < 0)
		free += BUFFER_SIZE;
	if ((free == 0) && (empty))
		free = BUFFER_SIZE;
	if (count > free)
		count = free;
	if (buffer_begin > buffer_end) {
		if (copy_from_user((void *)buffer_end, buf, count))
			return -EFAULT;

		buffer_end += count;
	} else {
		nbytes = data_buffer + BUFFER_SIZE - buffer_end;
		if (nbytes > count) {
			if (copy_from_user((void *)buffer_end, buf, count))
				return -EFAULT;
			buffer_end += count;
		} else {
			if (copy_from_user((void *)buffer_end, buf, nbytes))
				return -EFAULT;
			if (copy_from_user
			    ((void *)data_buffer, buf + nbytes, count - nbytes))
				return -EFAULT;
			buffer_end = data_buffer + count - nbytes;
		}
	}

	if (empty) {
		empty = 0;
		dac_audio_start_timer();
	}

	return count;
}

static ssize_t dac_audio_read(struct file *file, char *buf, size_t count,
			      loff_t * ppos)
{
	return -EINVAL;
}

static int dac_audio_open(struct inode *inode, struct file *file)
{
	if (file->f_mode & FMODE_READ)
		return -ENODEV;

	lock_kernel();
	if (in_use) {
		unlock_kernel();
		return -EBUSY;
	}

	in_use = 1;

	dac_audio_start();
	unlock_kernel();
	return 0;
}

static int dac_audio_release(struct inode *inode, struct file *file)
{
	dac_audio_sync();
	dac_audio_stop();
	in_use = 0;

	return 0;
}

const struct file_operations dac_audio_fops = {
      .read =		dac_audio_read,
      .write =		dac_audio_write,
      .unlocked_ioctl =	dac_audio_unlocked_ioctl,
      .open =		dac_audio_open,
      .release =	dac_audio_release,
};

static enum hrtimer_restart sh_dac_audio_timer(struct hrtimer *handle)
{
	if (!empty) {
		sh_dac_output(*buffer_begin, CONFIG_SOUND_SH_DAC_AUDIO_CHANNEL);
		buffer_begin++;

		if (buffer_begin == data_buffer + BUFFER_SIZE)
			buffer_begin = data_buffer;
		if (buffer_begin == buffer_end)
			empty = 1;
	}

	if (!empty)
		hrtimer_start(&hrtimer, wakeups_per_second, HRTIMER_MODE_REL);

	return HRTIMER_NORESTART;
}

static int __init dac_audio_init(void)
{
	if ((device_major = register_sound_dsp(&dac_audio_fops, -1)) < 0) {
		printk(KERN_ERR "Cannot register dsp device");
		return device_major;
	}

	in_use = 0;

	data_buffer = kmalloc(BUFFER_SIZE, GFP_KERNEL);
	if (data_buffer == NULL)
		return -ENOMEM;

	dac_audio_reset();
	rate = 8000;
	dac_audio_set_rate();

	/* Today: High Resolution Timer driven DAC playback.
	 * The timer callback gets called once per sample. Ouch.
	 *
	 * Future: A much better approach would be to use the
	 * SH7720 CMT+DMAC+DAC hardware combination like this:
	 * - Program sample rate using CMT0 or CMT1
	 * - Program DMAC to use CMT for timing and output to DAC
	 * - Play sound using DMAC, let CPU sleep.
	 * - While at it, rewrite this driver to use ALSA.
	 */

	hrtimer_init(&hrtimer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
	hrtimer.function = sh_dac_audio_timer;

	return 0;
}

static void __exit dac_audio_exit(void)
{
	unregister_sound_dsp(device_major);
	kfree((void *)data_buffer);
}

module_init(dac_audio_init);
module_exit(dac_audio_exit);

MODULE_AUTHOR("Andriy Skulysh, askulysh@image.kiev.ua");
MODULE_DESCRIPTION("SH DAC sound driver");
MODULE_LICENSE("GPL");