From 60507fe191f524e82986fa737e5b27b4d3ad9289 Mon Sep 17 00:00:00 2001 From: Matthias Reichl Date: Mon, 25 Apr 2016 13:39:39 +0000 Subject: [PATCH] ASoC: bcm2835: setup clock only if CPU is clock master We only need to enable the clock if we are a clock master. Code ported from bcm2708-i2s driver in Raspberry Pi tree. Original work by Zoltan Szenczi. Signed-off-by: Matthias Reichl Signed-off-by: Martin Sperl Signed-off-by: Mark Brown --- sound/soc/bcm/bcm2835-i2s.c | 11 +++++++++-- 1 file changed, 9 insertions(+), 2 deletions(-) diff --git a/sound/soc/bcm/bcm2835-i2s.c b/sound/soc/bcm/bcm2835-i2s.c index d2663e79ece1..a0026e2d2f0a 100644 --- a/sound/soc/bcm/bcm2835-i2s.c +++ b/sound/soc/bcm/bcm2835-i2s.c @@ -276,8 +276,15 @@ static int bcm2835_i2s_hw_params(struct snd_pcm_substream *substream, /* otherwise calculate a fitting block ratio */ bclk_ratio = 2 * data_length; - /* set target clock rate*/ - clk_set_rate(dev->clk, sampling_rate * bclk_ratio); + /* Clock should only be set up here if CPU is clock master */ + switch (dev->fmt & SND_SOC_DAIFMT_MASTER_MASK) { + case SND_SOC_DAIFMT_CBS_CFS: + case SND_SOC_DAIFMT_CBS_CFM: + clk_set_rate(dev->clk, sampling_rate * bclk_ratio); + break; + default: + break; + } /* Setup the frame format */ format = BCM2835_I2S_CHEN; -- 2.34.1