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 (file)
--- 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;
 }