2 * sound/oss/sh_dac_audio.c
4 * SH DAC based sound :(
6 * Copyright (C) 2004,2005 Andriy Skulysh
8 * This file is subject to the terms and conditions of the GNU General Public
9 * License. See the file "COPYING" in the main directory of this archive
12 #include <linux/module.h>
13 #include <linux/init.h>
14 #include <linux/sched.h>
15 #include <linux/linkage.h>
16 #include <linux/slab.h>
18 #include <linux/smp_lock.h>
19 #include <linux/sound.h>
20 #include <linux/smp_lock.h>
21 #include <linux/soundcard.h>
22 #include <linux/interrupt.h>
23 #include <linux/hrtimer.h>
25 #include <asm/uaccess.h>
27 #include <asm/delay.h>
28 #include <asm/clock.h>
30 #include <asm/machvec.h>
31 #include <mach/hp6xx.h>
32 #include <asm/hd64461.h>
34 #define MODNAME "sh_dac_audio"
36 #define BUFFER_SIZE 48000
40 static char *data_buffer, *buffer_begin, *buffer_end;
41 static int in_use, device_major;
42 static struct hrtimer hrtimer;
43 static ktime_t wakeups_per_second;
45 static void dac_audio_start_timer(void)
47 hrtimer_start(&hrtimer, wakeups_per_second, HRTIMER_MODE_REL);
50 static void dac_audio_stop_timer(void)
52 hrtimer_cancel(&hrtimer);
55 static void dac_audio_reset(void)
57 dac_audio_stop_timer();
58 buffer_begin = buffer_end = data_buffer;
62 static void dac_audio_sync(void)
68 static void dac_audio_start(void)
70 if (mach_is_hp6xx()) {
71 u16 v = __raw_readw(HD64461_GPADR);
72 v &= ~HD64461_GPADR_SPEAKER;
73 __raw_writew(v, HD64461_GPADR);
76 sh_dac_enable(CONFIG_SOUND_SH_DAC_AUDIO_CHANNEL);
78 static void dac_audio_stop(void)
80 dac_audio_stop_timer();
82 if (mach_is_hp6xx()) {
83 u16 v = __raw_readw(HD64461_GPADR);
84 v |= HD64461_GPADR_SPEAKER;
85 __raw_writew(v, HD64461_GPADR);
88 sh_dac_output(0, CONFIG_SOUND_SH_DAC_AUDIO_CHANNEL);
89 sh_dac_disable(CONFIG_SOUND_SH_DAC_AUDIO_CHANNEL);
92 static void dac_audio_set_rate(void)
94 wakeups_per_second = ktime_set(0, 1000000000 / rate);
97 static int dac_audio_ioctl(struct file *file,
98 unsigned int cmd, unsigned long arg)
104 return put_user(SOUND_VERSION, (int *)arg);
106 case SNDCTL_DSP_SYNC:
110 case SNDCTL_DSP_RESET:
114 case SNDCTL_DSP_GETFMTS:
115 return put_user(AFMT_U8, (int *)arg);
117 case SNDCTL_DSP_SETFMT:
118 return put_user(AFMT_U8, (int *)arg);
120 case SNDCTL_DSP_NONBLOCK:
121 spin_lock(&file->f_lock);
122 file->f_flags |= O_NONBLOCK;
123 spin_unlock(&file->f_lock);
126 case SNDCTL_DSP_GETCAPS:
129 case SOUND_PCM_WRITE_RATE:
133 dac_audio_set_rate();
135 return put_user(rate, (int *)arg);
137 case SNDCTL_DSP_STEREO:
138 return put_user(0, (int *)arg);
140 case SOUND_PCM_WRITE_CHANNELS:
141 return put_user(1, (int *)arg);
143 case SNDCTL_DSP_SETDUPLEX:
146 case SNDCTL_DSP_PROFILE:
149 case SNDCTL_DSP_GETBLKSIZE:
150 return put_user(BUFFER_SIZE, (int *)arg);
152 case SNDCTL_DSP_SETFRAGMENT:
156 printk(KERN_ERR "sh_dac_audio: unimplemented ioctl=0x%x\n",
163 static long dac_audio_unlocked_ioctl(struct file *file, u_int cmd, u_long arg)
168 ret = dac_audio_ioctl(file, cmd, arg);
174 static ssize_t dac_audio_write(struct file *file, const char *buf, size_t count,
185 free = buffer_begin - buffer_end;
189 if ((free == 0) && (empty))
193 if (buffer_begin > buffer_end) {
194 if (copy_from_user((void *)buffer_end, buf, count))
199 nbytes = data_buffer + BUFFER_SIZE - buffer_end;
200 if (nbytes > count) {
201 if (copy_from_user((void *)buffer_end, buf, count))
205 if (copy_from_user((void *)buffer_end, buf, nbytes))
208 ((void *)data_buffer, buf + nbytes, count - nbytes))
210 buffer_end = data_buffer + count - nbytes;
216 dac_audio_start_timer();
222 static ssize_t dac_audio_read(struct file *file, char *buf, size_t count,
228 static int dac_audio_open(struct inode *inode, struct file *file)
230 if (file->f_mode & FMODE_READ)
246 static int dac_audio_release(struct inode *inode, struct file *file)
255 const struct file_operations dac_audio_fops = {
256 .read = dac_audio_read,
257 .write = dac_audio_write,
258 .unlocked_ioctl = dac_audio_unlocked_ioctl,
259 .open = dac_audio_open,
260 .release = dac_audio_release,
263 static enum hrtimer_restart sh_dac_audio_timer(struct hrtimer *handle)
266 sh_dac_output(*buffer_begin, CONFIG_SOUND_SH_DAC_AUDIO_CHANNEL);
269 if (buffer_begin == data_buffer + BUFFER_SIZE)
270 buffer_begin = data_buffer;
271 if (buffer_begin == buffer_end)
276 hrtimer_start(&hrtimer, wakeups_per_second, HRTIMER_MODE_REL);
278 return HRTIMER_NORESTART;
281 static int __init dac_audio_init(void)
283 if ((device_major = register_sound_dsp(&dac_audio_fops, -1)) < 0) {
284 printk(KERN_ERR "Cannot register dsp device");
290 data_buffer = kmalloc(BUFFER_SIZE, GFP_KERNEL);
291 if (data_buffer == NULL)
296 dac_audio_set_rate();
298 /* Today: High Resolution Timer driven DAC playback.
299 * The timer callback gets called once per sample. Ouch.
301 * Future: A much better approach would be to use the
302 * SH7720 CMT+DMAC+DAC hardware combination like this:
303 * - Program sample rate using CMT0 or CMT1
304 * - Program DMAC to use CMT for timing and output to DAC
305 * - Play sound using DMAC, let CPU sleep.
306 * - While at it, rewrite this driver to use ALSA.
309 hrtimer_init(&hrtimer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
310 hrtimer.function = sh_dac_audio_timer;
315 static void __exit dac_audio_exit(void)
317 unregister_sound_dsp(device_major);
318 kfree((void *)data_buffer);
321 module_init(dac_audio_init);
322 module_exit(dac_audio_exit);
324 MODULE_AUTHOR("Andriy Skulysh, askulysh@image.kiev.ua");
325 MODULE_DESCRIPTION("SH DAC sound driver");
326 MODULE_LICENSE("GPL");