[PATCH 1/4 v3] pxa2xx-i2s: Proper hw initialization

[PATCH 1/4 v3] pxa2xx-i2s: Proper hw initialization

[Karl Beldan]

Make sure we are in a know good state at end of probe :
Reset FIFO logic and registers, and make sure REC and RPL functions
along with FIFO service are disabled (SACR0_RST enables REC and RPL).

Resetting loses current settings so remove reset from stream startup.
Now reset occurs only at probe.

Signed-off-by: Karl Beldan <karl.beldan@mobile-devices.fr>
---
 sound/soc/pxa/pxa2xx-i2s.c |   17 ++++++++++++++---
 1 files changed, 14 insertions(+), 3 deletions(-)

diff --git a/sound/soc/pxa/pxa2xx-i2s.c b/sound/soc/pxa/pxa2xx-i2s.c
index 2f4b6e4..59cc4f5 100644
--- a/sound/soc/pxa/pxa2xx-i2s.c
+++ b/sound/soc/pxa/pxa2xx-i2s.c
@@ -106,10 +106,8 @@ static int pxa2xx_i2s_startup(struct snd_pcm_substream
*substream,
 	if (IS_ERR(clk_i2s))
 		return PTR_ERR(clk_i2s);

-	if (!cpu_dai->active) {
-		SACR0 |= SACR0_RST;
+	if (!cpu_dai->active)
 		SACR0 = 0;
-	}

 	return 0;
 }
@@ -346,6 +344,19 @@ static int pxa2xx_i2s_probe(struct platform_device *dev)
 	if (ret != 0)
 		clk_put(clk_i2s);

+	/*
+	 * PXA Developer's Manual:
+	 * If SACR0[ENB] is toggled in the middle of a normal operation,
+	 * the SACR0[RST] bit must also be set and cleared to reset all
+	 * I2S controller registers.
+	 */
+	SACR0 = SACR0_RST;
+	SACR0 = 0;
+	/* Make sure RPL and REC are disabled */
+	SACR1 = SACR1_DRPL | SACR1_DREC;
+	/* Along with FIFO servicing */
+	SAIMR &= ~(SAIMR_RFS | SAIMR_TFS);
+
 	return ret;
 }

-- 
1.6.3.rc1.34.g0be9b

-- 
Karl

Re: [PATCH 1/4 v3] pxa2xx-i2s: Proper hw initialization

[Karl Beldan]

Karl Beldan wrote:
> Make sure we are in a know good state at end of probe :
> Reset FIFO logic and registers, and make sure REC and RPL functions
> along with FIFO service are disabled (SACR0_RST enables REC and RPL).
> 
> Resetting loses current settings so remove reset from stream startup.
> Now reset occurs only at probe.
> 

This differs from what you applied in that it includes 'removal of hw reset from
pxa2xx_i2s_startup'.
I understood including it in either one (1/4 or 2/4) is ok, since you had not
pushed it yet. Otherwise I'll have to post a [PATCH 2/4 v3] including the reset,
which would be identical to [PATCH 2/4] (initial version).
If I understand correctly from your replies, I should have posted [PATCH 1/4
v2]'s content with [PATCH 1/4 v3]'s Subject.

Thanks,

-- 
Karl

Re: [PATCH 1/4 v3] pxa2xx-i2s: Proper hw initialization

[Karl Beldan]

Karl Beldan wrote:
> Karl Beldan wrote:
>> Make sure we are in a know good state at end of probe :
>> Reset FIFO logic and registers, and make sure REC and RPL functions
>> along with FIFO service are disabled (SACR0_RST enables REC and RPL).
>>
>> Resetting loses current settings so remove reset from stream startup.
>> Now reset occurs only at probe.
>>
> 
> This differs from what you applied in that it includes 'removal of hw reset from
> pxa2xx_i2s_startup'.
> I understood including it in either one (1/4 or 2/4) is ok, since you had not
> pushed it yet. Otherwise I'll have to post a [PATCH 2/4 v3] including the reset,
> which would be identical to [PATCH 2/4] (initial version).
I meant 'which would be identical to [PATCH 2/4] (initial version) + reset'.


-- 
Karl

Re: [PATCH 1/4 v3] pxa2xx-i2s: Proper hw initialization

[Mark Brown]

On Thu, May 14, 2009 at 10:25:42AM +0200, Karl Beldan wrote:

> @@ -106,10 +106,8 @@ static int pxa2xx_i2s_startup(struct snd_pcm_substream
> *substream,

Unfortunately your MUA is mangling the patches by word wrapping.  I've
resolved the problems by hand this once but you might want to take a
look at Documentation/email-clients.txt for tips on setting things up.

Anyway, they're all applied now and pass smoke testing here - thanks a
lot!

Re: [PATCH 1/4 v3] pxa2xx-i2s: Proper hw initialization

[Karl Beldan]

Mark Brown wrote:
> On Thu, May 14, 2009 at 10:25:42AM +0200, Karl Beldan wrote:
> 
>> @@ -106,10 +106,8 @@ static int pxa2xx_i2s_startup(struct snd_pcm_substream
>> *substream,
> 
> Unfortunately your MUA is mangling the patches by word wrapping.  I've
> resolved the problems by hand this once but you might want to take a
> look at Documentation/email-clients.txt for tips on setting things up.
> 
Sorry for that and thanks for your review.

> Anyway, they're all applied now and pass smoke testing here - thanks a
> lot!
Great.

-- 
Karl