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Commit 639138a9 authored by Magnus Damm's avatar Magnus Damm Committed by Paul Mundt
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sound: oss: sh_dac_audio timer fixes. 



This patch modifies sh_dac_audio in the following ways:

- use high resolution timer instead of TMU1
- fix cpu/dac.h include
- add future rewrite comment

Signed-off-by: default avatarMagnus Damm <damm@igel.co.jp>
Signed-off-by: default avatarPaul Mundt <lethal@linux-sh.org>
parent bec36eca

sound/oss/Kconfig

+1 −1
Original line number Diff line number Diff line
@@ -561,7 +561,7 @@ endif # SOUND_OSS 


config SOUND_SH_DAC_AUDIO

	tristate "SuperH DAC audio support"

	depends on CPU_SH3

	depends on CPU_SH3 && HIGH_RES_TIMERS



config SOUND_SH_DAC_AUDIO_CHANNEL

	int "DAC channel"

sound/oss/sh_dac_audio.c

+32 −53
Original line number Diff line number Diff line
@@ -18,47 +18,36 @@ 
#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 <asm/cpu/dac.h>

#include <asm/cpu/timer.h>

#include <cpu/dac.h>

#include <asm/machvec.h>

#include <mach/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 struct hrtimer hrtimer;

static ktime_t wakeups_per_second;



static void dac_audio_start_timer(void)

{

	u8 tstr;



	tstr = ctrl_inb(TMU_TSTR);

	tstr |= TMU1_TSTR_INIT;

	ctrl_outb(tstr, TMU_TSTR);

	hrtimer_start(&hrtimer, wakeups_per_second, HRTIMER_MODE_REL);

}



static void dac_audio_stop_timer(void)

{

	u8 tstr;



	tstr = ctrl_inb(TMU_TSTR);

	tstr &= ~TMU1_TSTR_INIT;

	ctrl_outb(tstr, TMU_TSTR);

	hrtimer_cancel(&hrtimer);

}



static void dac_audio_reset(void)
@@ -77,22 +66,21 @@ static void dac_audio_sync(void) 
static void dac_audio_start(void)

{

	if (mach_is_hp6xx()) {

		u16 v = inw(HD64461_GPADR);

		u16 v = __raw_readw(HD64461_GPADR);

		v &= ~HD64461_GPADR_SPEAKER;

		outw(v, HD64461_GPADR);

		__raw_writew(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);

		u16 v = __raw_readw(HD64461_GPADR);

		v |= HD64461_GPADR_SPEAKER;

		outw(v, HD64461_GPADR);

		__raw_writew(v, HD64461_GPADR);

	}



	sh_dac_output(0, CONFIG_SOUND_SH_DAC_AUDIO_CHANNEL);
@@ -101,14 +89,7 @@ static void dac_audio_stop(void) 


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);

	wakeups_per_second = ktime_set(0, 1000000000 / rate);

}



static int dac_audio_ioctl(struct inode *inode, struct file *file,
@@ -265,32 +246,26 @@ const struct file_operations dac_audio_fops = { 
      .release =	dac_audio_release,

};



static irqreturn_t timer1_interrupt(int irq, void *dev)

static enum hrtimer_restart sh_dac_audio_timer(struct hrtimer *handle)

{

	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) {

		if (buffer_begin == buffer_end)

			empty = 1;

			dac_audio_stop_timer();

		}

	}

	return IRQ_HANDLED;



	if (!empty)

		hrtimer_start(&hrtimer, wakeups_per_second, HRTIMER_MODE_REL);



	return HRTIMER_NORESTART;

}



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;
@@ -306,21 +281,25 @@ static int __init dac_audio_init(void) 
	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;

	}

	/* 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)

{

	free_irq(TIMER1_IRQ, 0);



	unregister_sound_dsp(device_major);

	kfree((void *)data_buffer);

}