ASoC: sgtl5000: add delay before first I2C access

commit 58cc9c9a175885bbf6bae3acf18233d0a8229a84 upstream.

To quote from section 1.3.1 of the data sheet:
	The SGTL5000 has an internal reset that is deasserted
	8 SYS_MCLK cycles after all power rails have been brought
	up. After this time, communication can start

	...
	1.0us represents 8 SYS_MCLK cycles at the minimum 8.0 MHz SYS_MCLK.

Signed-off-by: Eric Nelson <eric.nelson@boundarydevices.com>
Reviewed-by: Fabio Estevam <fabio.estevam@freescale.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/sound/soc/codecs/sgtl5000.c b/sound/soc/codecs/sgtl5000.c
index 23670737116ea006b60ffbe8552059bbbfc87282..3b5f565a23a524e8bdc61bbb905473606cf60144 100644 (file)
--- a/sound/soc/codecs/sgtl5000.c
+++ b/sound/soc/codecs/sgtl5000.c
@@ -1242,6 +1242,9 @@ static int sgtl5000_enable_regulators(struct snd_soc_codec *codec)
        /* wait for all power rails bring up */
        udelay(10);
 
+       /* Need 8 clocks before I2C accesses */
+       udelay(1);
+
        /* read chip information */
        reg = snd_soc_read(codec, SGTL5000_CHIP_ID);
        if (((reg & SGTL5000_PARTID_MASK) >> SGTL5000_PARTID_SHIFT) !=