This is a note to let you know that I've just added the patch titled
ASoC: sgtl5000: add delay before first I2C access
to the 3.10-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
asoc-sgtl5000-add-delay-before-first-i2c-access.patch
and it can be found in the queue-3.10 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From 58cc9c9a175885bbf6bae3acf18233d0a8229a84 Mon Sep 17 00:00:00 2001
From: Eric Nelson <eric.nelson@xxxxxxxxxxxxxxxxxxx>
Date: Fri, 30 Jan 2015 14:07:55 -0700
Subject: ASoC: sgtl5000: add delay before first I2C access
From: Eric Nelson <eric.nelson@xxxxxxxxxxxxxxxxxxx>
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@xxxxxxxxxxxxxxxxxxx>
Reviewed-by: Fabio Estevam <fabio.estevam@xxxxxxxxxxxxx>
Signed-off-by: Mark Brown <broonie@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
sound/soc/codecs/sgtl5000.c | 3 +++
1 file changed, 3 insertions(+)
--- a/sound/soc/codecs/sgtl5000.c
+++ b/sound/soc/codecs/sgtl5000.c
@@ -1242,6 +1242,9 @@ static int sgtl5000_enable_regulators(st
/* 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) !=
Patches currently in stable-queue which might be from eric.nelson@xxxxxxxxxxxxxxxxxxx are
queue-3.10/asoc-sgtl5000-add-delay-before-first-i2c-access.patch
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