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Commit cdc65fbe authored by Manuel Lauss's avatar Manuel Lauss Committed by Mark Brown
Browse files

ASoC: au1x: PSC-AC97 bugfixes 



This patch fixes the following bugs:

- only reprogram bitdepth if it has changed since last call to hw_params.
- add locking inside ac97_read/write functions:
  When reprogramming sample depth, the ac97 unit has to be disabled,
  which should not be done in the middle of codec register accesses.

- retry timed-out codec register accesses.

- wait for status bits to set/clear when starting/stopping various
  functional blocks; very important after reenabling AC97 unit else
  sound may be distorted (e.g. high-pitch noise in 1kHz sine wave).

- clear fifos before/after starting/stopping RX/TX.

- longer timeouts waiting for PSC/AC97 ready after cold reset
  with certain codecs this can take ridiculous amounts of time.

Run-tested on various Au1200 platforms with various codecs.

Signed-off-by: default avatarManuel Lauss <manuel.lauss@gmail.com>
Signed-off-by: default avatarMark Brown <broonie@opensource.wolfsonmicro.com>
parent 87831cb6

sound/soc/au1x/psc-ac97.c

+96 −33
Original line number Diff line number Diff line 
/*

 * Au12x0/Au1550 PSC ALSA ASoC audio support.

 *

 * (c) 2007-2008 MSC Vertriebsges.m.b.H.,

 *	Manuel Lauss <mano@roarinelk.homelinux.net>

 * (c) 2007-2009 MSC Vertriebsges.m.b.H.,

 *	Manuel Lauss <manuel.lauss@gmail.com>

 *

 * This program is free software; you can redistribute it and/or modify

 * it under the terms of the GNU General Public License version 2 as
@@ -19,6 +19,7 @@ 
#include <linux/module.h>

#include <linux/device.h>

#include <linux/delay.h>

#include <linux/mutex.h>

#include <linux/suspend.h>

#include <sound/core.h>

#include <sound/pcm.h>
@@ -29,6 +30,9 @@ 


#include "psc.h"



/* how often to retry failed codec register reads/writes */

#define AC97_RW_RETRIES	5



#define AC97_DIR	\

	(SND_SOC_DAIDIR_PLAYBACK | SND_SOC_DAIDIR_CAPTURE)
@@ -45,6 +49,9 @@ 
#define AC97PCR_CLRFIFO(stype)	\

	((stype) == PCM_TX ? PSC_AC97PCR_TC : PSC_AC97PCR_RC)



#define AC97STAT_BUSY(stype)	\

	((stype) == PCM_TX ? PSC_AC97STAT_TB : PSC_AC97STAT_RB)



/* instance data. There can be only one, MacLeod!!!! */

static struct au1xpsc_audio_data *au1xpsc_ac97_workdata;
@@ -54,24 +61,33 @@ static unsigned short au1xpsc_ac97_read(struct snd_ac97 *ac97, 
{

	/* FIXME */

	struct au1xpsc_audio_data *pscdata = au1xpsc_ac97_workdata;

	unsigned short data, tmo;

	unsigned short data, retry, tmo;



	au_writel(PSC_AC97CDC_RD | PSC_AC97CDC_INDX(reg), AC97_CDC(pscdata));

	au_writel(PSC_AC97EVNT_CD, AC97_EVNT(pscdata));

	au_sync();



	tmo = 1000;

	while ((!(au_readl(AC97_EVNT(pscdata)) & PSC_AC97EVNT_CD)) && --tmo)

	retry = AC97_RW_RETRIES;

	do {

		mutex_lock(&pscdata->lock);



		au_writel(PSC_AC97CDC_RD | PSC_AC97CDC_INDX(reg),

			  AC97_CDC(pscdata));

		au_sync();



		tmo = 2000;

		while ((!(au_readl(AC97_EVNT(pscdata)) & PSC_AC97EVNT_CD))

			&& --tmo)

			udelay(2);



	if (!tmo)

		data = 0xffff;

	else

		data = au_readl(AC97_CDC(pscdata)) & 0xffff;



		au_writel(PSC_AC97EVNT_CD, AC97_EVNT(pscdata));

		au_sync();



	return data;

		mutex_unlock(&pscdata->lock);

	} while (--retry && !tmo);



	return retry ? data : 0xffff;

}



/* AC97 controller writes to codec register */
@@ -80,16 +96,29 @@ static void au1xpsc_ac97_write(struct snd_ac97 *ac97, unsigned short reg, 
{

	/* FIXME */

	struct au1xpsc_audio_data *pscdata = au1xpsc_ac97_workdata;

	unsigned int tmo;

	unsigned int tmo, retry;



	au_writel(PSC_AC97CDC_INDX(reg) | (val & 0xffff), AC97_CDC(pscdata));

	au_writel(PSC_AC97EVNT_CD, AC97_EVNT(pscdata));

	au_sync();

	tmo = 1000;

	while ((!(au_readl(AC97_EVNT(pscdata)) & PSC_AC97EVNT_CD)) && --tmo)



	retry = AC97_RW_RETRIES;

	do {

		mutex_lock(&pscdata->lock);



		au_writel(PSC_AC97CDC_INDX(reg) | (val & 0xffff),

			  AC97_CDC(pscdata));

		au_sync();



		tmo = 2000;

		while ((!(au_readl(AC97_EVNT(pscdata)) & PSC_AC97EVNT_CD))

		       && --tmo)

			udelay(2);



		au_writel(PSC_AC97EVNT_CD, AC97_EVNT(pscdata));

		au_sync();



		mutex_unlock(&pscdata->lock);

	} while (--retry && !tmo);

}



/* AC97 controller asserts a warm reset */
@@ -129,9 +158,9 @@ static void au1xpsc_ac97_cold_reset(struct snd_ac97 *ac97) 
	au_sync();



	/* wait for PSC to indicate it's ready */

	i = 100000;

	i = 1000;

	while (!((au_readl(AC97_STAT(pscdata)) & PSC_AC97STAT_SR)) && (--i))

		au_sync();

		msleep(1);



	if (i == 0) {

		printk(KERN_ERR "au1xpsc-ac97: PSC not ready!\n");
@@ -143,9 +172,9 @@ static void au1xpsc_ac97_cold_reset(struct snd_ac97 *ac97) 
	au_sync();



	/* wait for AC97 core to become ready */

	i = 100000;

	i = 1000;

	while (!((au_readl(AC97_STAT(pscdata)) & PSC_AC97STAT_DR)) && (--i))

		au_sync();

		msleep(1);

	if (i == 0)

		printk(KERN_ERR "au1xpsc-ac97: AC97 ctrl not ready\n");

}
@@ -165,12 +194,12 @@ static int au1xpsc_ac97_hw_params(struct snd_pcm_substream *substream, 
{

	/* FIXME */

	struct au1xpsc_audio_data *pscdata = au1xpsc_ac97_workdata;

	unsigned long r, stat;

	unsigned long r, ro, stat;

	int chans, stype = SUBSTREAM_TYPE(substream);



	chans = params_channels(params);



	r = au_readl(AC97_CFG(pscdata));

	r = ro = au_readl(AC97_CFG(pscdata));

	stat = au_readl(AC97_STAT(pscdata));



	/* already active? */
@@ -180,9 +209,6 @@ static int au1xpsc_ac97_hw_params(struct snd_pcm_substream *substream, 
		    (pscdata->rate != params_rate(params)))

			return -EINVAL;

	} else {

		/* disable AC97 device controller first */

		au_writel(r & ~PSC_AC97CFG_DE_ENABLE, AC97_CFG(pscdata));

		au_sync();



		/* set sample bitdepth: REG[24:21]=(BITS-2)/2 */

		r &= ~PSC_AC97CFG_LEN_MASK;
@@ -199,14 +225,40 @@ static int au1xpsc_ac97_hw_params(struct snd_pcm_substream *substream, 
			r |= PSC_AC97CFG_RXSLOT_ENA(4);

		}



		/* finally enable the AC97 controller again */

		/* do we need to poke the hardware? */

		if (!(r ^ ro))

			goto out;



		/* ac97 engine is about to be disabled */

		mutex_lock(&pscdata->lock);



		/* disable AC97 device controller first... */

		au_writel(r & ~PSC_AC97CFG_DE_ENABLE, AC97_CFG(pscdata));

		au_sync();



		/* ...wait for it... */

		while (au_readl(AC97_STAT(pscdata)) & PSC_AC97STAT_DR)

			asm volatile ("nop");



		/* ...write config... */

		au_writel(r, AC97_CFG(pscdata));

		au_sync();



		/* ...enable the AC97 controller again... */

		au_writel(r | PSC_AC97CFG_DE_ENABLE, AC97_CFG(pscdata));

		au_sync();



		/* ...and wait for ready bit */

		while (!(au_readl(AC97_STAT(pscdata)) & PSC_AC97STAT_DR))

			asm volatile ("nop");



		mutex_unlock(&pscdata->lock);



		pscdata->cfg = r;

		pscdata->rate = params_rate(params);

	}



out:

	return 0;

}
@@ -222,6 +274,8 @@ static int au1xpsc_ac97_trigger(struct snd_pcm_substream *substream, 
	switch (cmd) {

	case SNDRV_PCM_TRIGGER_START:

	case SNDRV_PCM_TRIGGER_RESUME:

		au_writel(AC97PCR_CLRFIFO(stype), AC97_PCR(pscdata));

		au_sync();

		au_writel(AC97PCR_START(stype), AC97_PCR(pscdata));

		au_sync();

		break;
@@ -229,6 +283,13 @@ static int au1xpsc_ac97_trigger(struct snd_pcm_substream *substream, 
	case SNDRV_PCM_TRIGGER_SUSPEND:

		au_writel(AC97PCR_STOP(stype), AC97_PCR(pscdata));

		au_sync();



		while (au_readl(AC97_STAT(pscdata)) & AC97STAT_BUSY(stype))

			asm volatile ("nop");



		au_writel(AC97PCR_CLRFIFO(stype), AC97_PCR(pscdata));

		au_sync();



		break;

	default:

		ret = -EINVAL;
@@ -251,6 +312,8 @@ static int au1xpsc_ac97_probe(struct platform_device *pdev, 
	if (!au1xpsc_ac97_workdata)

		return -ENOMEM;



	mutex_init(&au1xpsc_ac97_workdata->lock);



	r = platform_get_resource(pdev, IORESOURCE_MEM, 0);

	if (!r) {

		ret = -ENODEV;
@@ -386,4 +449,4 @@ module_exit(au1xpsc_ac97_exit); 


MODULE_LICENSE("GPL");

MODULE_DESCRIPTION("Au12x0/Au1550 PSC AC97 ALSA ASoC audio driver");

MODULE_AUTHOR("Manuel Lauss <mano@roarinelk.homelinux.net>");
 
MODULE_AUTHOR("Manuel Lauss <manuel.lauss@gmail.com>");

sound/soc/au1x/psc.h

+1 −0
Original line number Diff line number Diff line
@@ -29,6 +29,7 @@ struct au1xpsc_audio_data { 


	unsigned long pm[2];

	struct resource *ioarea;

	struct mutex lock;

};



#define PCM_TX	0