From 63e23a08bd0bcf782f870bacaf82404e36a6a1bd Mon Sep 17 00:00:00 2001 From: Matthias Reichl Date: Sun, 11 Oct 2015 15:25:51 +0200 Subject: [PATCH] bcm2835-i2s: setup clock only if CPU is clock master Code ported from bcm2708-i2s driver in Raspberry Pi tree. RPi commit c14827ecdaa36607f6110f9ce8df96e698672191 ("bcm2708: Allow option card devices to be configured via DT") Original work by Zoltan Szenczi, committed to RPi tree by Phil Elwell. Signed-off-by: Matthias Reichl --- sound/soc/bcm/bcm2835-i2s.c | 28 +++++++++++++++++++--------- 1 file changed, 19 insertions(+), 9 deletions(-) --- a/sound/soc/bcm/bcm2835-i2s.c +++ b/sound/soc/bcm/bcm2835-i2s.c @@ -411,15 +411,25 @@ static int bcm2835_i2s_hw_params(struct divf = dividend & BCM2835_CLK_DIVF_MASK; } - /* Set clock divider */ - regmap_write(dev->clk_regmap, BCM2835_CLK_PCMDIV_REG, BCM2835_CLK_PASSWD - | BCM2835_CLK_DIVI(divi) - | BCM2835_CLK_DIVF(divf)); + /* 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: + /* Set clock divider */ + regmap_write(dev->clk_regmap, BCM2835_CLK_PCMDIV_REG, + BCM2835_CLK_PASSWD + | BCM2835_CLK_DIVI(divi) + | BCM2835_CLK_DIVF(divf)); - /* Setup clock, but don't start it yet */ - regmap_write(dev->clk_regmap, BCM2835_CLK_PCMCTL_REG, BCM2835_CLK_PASSWD - | BCM2835_CLK_MASH(mash) - | BCM2835_CLK_SRC(clk_src)); + /* Setup clock, but don't start it yet */ + regmap_write(dev->clk_regmap, BCM2835_CLK_PCMCTL_REG, + BCM2835_CLK_PASSWD + | BCM2835_CLK_MASH(mash) + | BCM2835_CLK_SRC(clk_src)); + break; + default: + break; + } /* Setup the frame format */ format = BCM2835_I2S_CHEN;