From: Eric Nelson Date: Fri, 30 Jan 2015 21:07:55 +0000 (-0700) Subject: ASoC: sgtl5000: add delay before first I2C access X-Git-Url: http://git.mmlx.us/?a=commitdiff_plain;h=48cc051f29814e8c8d4498a4fb99204fa31e30e2;p=linux-edison.git 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 Reviewed-by: Fabio Estevam Signed-off-by: Mark Brown Signed-off-by: Greg Kroah-Hartman --- diff --git a/sound/soc/codecs/sgtl5000.c b/sound/soc/codecs/sgtl5000.c index 23670737116..3b5f565a23a 100644 --- 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) !=