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authorEric Nelson <eric.nelson@boundarydevices.com>2015-01-30 14:07:55 -0700
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2015-02-11 14:48:17 +0800
commit48cc051f29814e8c8d4498a4fb99204fa31e30e2 (patch)
treea1e8b31d5f6255ca810ae16050b09b86ccac2539
parentd9c3bfc0e830c37c12961a26311f603eaea24046 (diff)
downloadlwn-48cc051f29814e8c8d4498a4fb99204fa31e30e2.tar.gz
lwn-48cc051f29814e8c8d4498a4fb99204fa31e30e2.zip
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>
-rw-r--r--sound/soc/codecs/sgtl5000.c3
1 files changed, 3 insertions, 0 deletions
diff --git a/sound/soc/codecs/sgtl5000.c b/sound/soc/codecs/sgtl5000.c
index 23670737116e..3b5f565a23a5 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) !=