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From: Charles Keepax <ckeepax@opensource.wolfsonmicro.com>
To: broonie@kernel.org
Cc: alsa-devel@alsa-project.org, patches@opensource.wolfsonmicro.com,
	lgirdwood@gmail.com
Subject: [PATCH] ASoC: arizona: Add 32uS delay after putting FLL into freerun
Date: Mon, 30 Nov 2015 17:37:28 +0000	[thread overview]
Message-ID: <1448905048-13862-1-git-send-email-ckeepax@opensource.wolfsonmicro.com> (raw)

When switching between two clock sources using the FLL freerun to smooth
the transition we should wait 32uS after putting the FLL into freerun
before we proceed. In practice we appear to be getting enough delay from
the surrounding code, but better to make it explicit.

Signed-off-by: Charles Keepax <ckeepax@opensource.wolfsonmicro.com>
---
 sound/soc/codecs/arizona.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/sound/soc/codecs/arizona.c b/sound/soc/codecs/arizona.c
index e76ecc7..a23f7d1 100644
--- a/sound/soc/codecs/arizona.c
+++ b/sound/soc/codecs/arizona.c
@@ -2212,9 +2212,9 @@ static int arizona_enable_fll(struct arizona_fll *fll)
 		/* Facilitate smooth refclk across the transition */
 		regmap_update_bits_async(fll->arizona->regmap, fll->base + 0x9,
 					 ARIZONA_FLL1_GAIN_MASK, 0);
-		regmap_update_bits_async(fll->arizona->regmap, fll->base + 1,
-					 ARIZONA_FLL1_FREERUN,
-					 ARIZONA_FLL1_FREERUN);
+		regmap_update_bits(fll->arizona->regmap, fll->base + 1,
+				   ARIZONA_FLL1_FREERUN, ARIZONA_FLL1_FREERUN);
+		udelay(32);
 	}
 
 	/*
-- 
2.1.4

             reply	other threads:[~2015-11-30 17:37 UTC|newest]

Thread overview: 5+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2015-11-30 17:37 Charles Keepax [this message]
2015-12-01 22:59 ` Applied "ASoC: arizona: Add 32uS delay after putting FLL into freerun" to the asoc tree Mark Brown
  -- strict thread matches above, loose matches on Subject: below --
2015-11-26 14:03 [PATCH] ASoC: arizona: Add 32uS delay after putting FLL into freerun Charles Keepax
2015-11-27 12:26 ` Mark Brown
2015-11-27 13:05   ` Charles Keepax

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