sound/oss/sh_dac_audio.c - kernel/prism - Git at Google

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

 	if (count < 0)
 		return -EINVAL;

 	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;
 	if (in_use)
 		return -EBUSY;

 	in_use = 1;

 	dac_audio_start();

 	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,
       .ioctl =	dac_audio_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");
	/*
	* 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/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 inode inode, 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 ssize_t dac_audio_write(struct file file, const char buf, size_t count,
	loff_t * ppos)
	{
	int free;
	int nbytes;

	if (count < 0)
	return -EINVAL;

	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;
	if (in_use)
	return -EBUSY;

	in_use = 1;

	dac_audio_start();

	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,
	.ioctl = dac_audio_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");