[3.16.y-ckt stable] Patch "ASoC: sgtl5000: add delay before first I2C access" has been added to staging queue

[Luis Henriques]

This is a note to let you know that I have just added a patch titled

    ASoC: sgtl5000: add delay before first I2C access

to the linux-3.16.y-queue branch of the 3.16.y-ckt extended stable tree 
which can be found at:

 http://kernel.ubuntu.com/git?p=ubuntu/linux.git;a=shortlog;h=refs/heads/linux-3.16.y-queue

This patch is scheduled to be released in version 3.16.7-ckt7.

If you, or anyone else, feels it should not be added to this tree, please 
reply to this email.

For more information about the 3.16.y-ckt tree, see
https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable

Thanks.
-Luis

------

>From 82adf3502b7f6d29fd541ef0205aa6f4c8aa052a Mon Sep 17 00:00:00 2001
From: Eric Nelson <eric.nelson at boundarydevices.com>
Date: Fri, 30 Jan 2015 14:07:55 -0700
Subject: 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 at boundarydevices.com>
Reviewed-by: Fabio Estevam <fabio.estevam at freescale.com>
Signed-off-by: Mark Brown <broonie at kernel.org>
Signed-off-by: Luis Henriques <luis.henriques at canonical.com>
---
 sound/soc/codecs/sgtl5000.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/sound/soc/codecs/sgtl5000.c b/sound/soc/codecs/sgtl5000.c
index f039d668266e..a62d340aa98a 100644
--- a/sound/soc/codecs/sgtl5000.c
+++ b/sound/soc/codecs/sgtl5000.c
@@ -1463,6 +1463,9 @@ static int sgtl5000_i2c_probe(struct i2c_client *client,
 	if (ret)
 		return ret;

+	/* Need 8 clocks before I2C accesses */
+	udelay(1);
+
 	/* read chip information */
 	ret = regmap_read(sgtl5000->regmap, SGTL5000_CHIP_ID, &reg);
 	if (ret)
--
2.1.4