From: Matthias Reichl <hias@xxxxxxxxx>
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 <hias@xxxxxxxxx>
Signed-off-by: Martin Sperl <kernel@xxxxxxxxxxxxxxxx>
---
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 d2663e7..a0026e2 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;
--
2.1.4
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