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sound: oss: sh_dac_audio timer fixes.

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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: Magnus Damm <damm@igel.co.jp>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
This commit is contained in:
Magnus Damm 2009-05-15 12:07:17 +09:00 committed by Paul Mundt
parent bec36eca6f
commit 639138a991
2 changed files with 33 additions and 54 deletions
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2
sound/oss/Kconfig
View file

@ -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"

85
sound/oss/sh_dac_audio.c
View file

@ -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)
@ -77,38 +66,30 @@ 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);
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);
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);
}