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root/sound/oss/sh_dac_audio.c

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DEFINITIONS

This source file includes following definitions.
  1. dac_audio_start_timer
  2. dac_audio_stop_timer
  3. dac_audio_reset
  4. dac_audio_sync
  5. dac_audio_start
  6. dac_audio_stop
  7. dac_audio_set_rate
  8. dac_audio_ioctl
  9. dac_audio_write
  10. dac_audio_read
  11. dac_audio_open
  12. dac_audio_release
  13. timer1_interrupt
  14. dac_audio_init
  15. dac_audio_exit

/*
 * 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 <asm/io.h>
#include <asm/uaccess.h>
#include <asm/irq.h>
#include <asm/delay.h>
#include <asm/clock.h>
#include <asm/cpu/dac.h>
#include <asm/cpu/timer.h>
#include <asm/machvec.h>
#include <asm/hp6xx.h>
#include <asm/hd64461.h>

#define MODNAME "sh_dac_audio"

#define TMU_TOCR_INIT   0x00

#define TMU1_TCR_INIT   0x0020  /* Clock/4, rising edge; interrupt on */
#define TMU1_TSTR_INIT  0x02    /* Bit to turn on TMU1 */

#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 void dac_audio_start_timer(void)
{
        u8 tstr;

        tstr = ctrl_inb(TMU_TSTR);
        tstr |= TMU1_TSTR_INIT;
        ctrl_outb(tstr, TMU_TSTR);
}

static void dac_audio_stop_timer(void)
{
        u8 tstr;

        tstr = ctrl_inb(TMU_TSTR);
        tstr &= ~TMU1_TSTR_INIT;
        ctrl_outb(tstr, TMU_TSTR);
}

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 = inw(HD64461_GPADR);
                v &= ~HD64461_GPADR_SPEAKER;
                outw(v, HD64461_GPADR);
        }

        sh_dac_enable(CONFIG_SOUND_SH_DAC_AUDIO_CHANNEL);
        ctrl_outw(TMU1_TCR_INIT, TMU1_TCR);
}
static void dac_audio_stop(void)
{
        dac_audio_stop_timer();

        if (mach_is_hp6xx()) {
                u16 v = inw(HD64461_GPADR);
                v |= HD64461_GPADR_SPEAKER;
                outw(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)
{
        unsigned long interval;
        struct clk *clk;

        clk = clk_get(NULL, "module_clk");
        interval = (clk_get_rate(clk) / 4) / rate;
        clk_put(clk);
        ctrl_outl(interval, TMU1_TCOR);
        ctrl_outl(interval, TMU1_TCNT);
}

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:
                file->f_flags |= O_NONBLOCK;
                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 irqreturn_t timer1_interrupt(int irq, void *dev)
{
        unsigned long timer_status;

        timer_status = ctrl_inw(TMU1_TCR);
        timer_status &= ~0x100;
        ctrl_outw(timer_status, TMU1_TCR);

        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;
                        dac_audio_stop_timer();
                }
        }
        return IRQ_HANDLED;
}

static int __init dac_audio_init(void)
{
        int retval;

        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();

        retval =
            request_irq(TIMER1_IRQ, timer1_interrupt, IRQF_DISABLED, MODNAME, 0);
        if (retval < 0) {
                printk(KERN_ERR "sh_dac_audio: IRQ %d request failed\n",
                       TIMER1_IRQ);
                return retval;
        }

        return 0;
}

static void __exit dac_audio_exit(void)
{
        free_irq(TIMER1_IRQ, 0);

        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");

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