diff options
author | Magnus Damm <damm@igel.co.jp> | 2009-05-15 12:07:17 +0900 |
---|---|---|
committer | Paul Mundt <lethal@linux-sh.org> | 2009-05-15 12:07:17 +0900 |
commit | 639138a991aaf1a3f65cc66700d097edc5f602fe (patch) | |
tree | ef3849e8a8ffb0f8b1396f4df826c05bd657b0ca /sound/oss/sh_dac_audio.c | |
parent | bec36eca6f5d1d83a9c3733fc40ba173ad849df2 (diff) |
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: Magnus Damm <damm@igel.co.jp>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
Diffstat (limited to 'sound/oss/sh_dac_audio.c')
-rw-r--r-- | sound/oss/sh_dac_audio.c | 85 |
1 files changed, 32 insertions, 53 deletions
diff --git a/sound/oss/sh_dac_audio.c b/sound/oss/sh_dac_audio.c index 78cfb66e4c5..b2ed8757542 100644 --- a/sound/oss/sh_dac_audio.c +++ b/sound/oss/sh_dac_audio.c @@ -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); } |