From: Karl Beldan <karl.beldan@gmail.com>
Date: Thu, 14 May 2009 08:25:42 +0000 (+0200)
Subject: ASoC: pxa2xx-i2s: Proper hw initialization
X-Git-Tag: v2.6.31-rc2~6^2~13^2~57^2~2^2~3
X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=b243b77c708665d7af8c5e42611c27c89f918788;p=profile%2Fcommon%2Fkernel-common.git

ASoC: pxa2xx-i2s: Proper hw initialization

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>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
---

diff --git a/sound/soc/pxa/pxa2xx-i2s.c b/sound/soc/pxa/pxa2xx-i2s.c
index 6014577..bb8630b 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;
 }
@@ -347,6 +345,19 @@ 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;
 }