[alsa-devel] [PATCH] imx-ssi.c: fix I2S slave setup

[Sascha Hauer]

On Wed, May 26, 2010 at 06:37:53PM +0200, Eric Bénard wrote:
> * without this fix, the waveform on the SSI port are not real
> I2S signal (at least on i.MX27's SSI4)
> 
> * original Freescale's driver has
> 	if (((fmt & SND_SOC_DAIFMT_FORMAT_MASK) == SND_SOC_DAIFMT_I2S)
> 	    && ssi_mode->network_mode) {
> 		scr &= ~SSI_SCR_I2S_MODE_MASK;
> 		scr |= SSI_SCR_I2S_MODE_SLAVE;
> 	}
> So as now the SSI is set in network mode as a default when running in
> I2S format, it seems reasonable to also set I2S_MODE_SLAVE
> 
> Signed-off-by: Eric Bénard <eric at eukrea.com>
> ---
>  sound/soc/imx/imx-ssi.c |    4 +---
>  1 files changed, 1 insertions(+), 3 deletions(-)
> 
> diff --git a/sound/soc/imx/imx-ssi.c b/sound/soc/imx/imx-ssi.c
> index 80b4fee..c5e1626 100644
> --- a/sound/soc/imx/imx-ssi.c
> +++ b/sound/soc/imx/imx-ssi.c
> @@ -83,8 +83,6 @@ static int imx_ssi_set_dai_tdm_slot(struct snd_soc_dai *cpu_dai,
>  /*
>   * SSI DAI format configuration.
>   * Should only be called when port is inactive (i.e. SSIEN = 0).
> - * Note: We don't use the I2S modes but instead manually configure the
> - * SSI for I2S because the I2S mode is only a register preset.
>   */
>  static int imx_ssi_set_dai_fmt(struct snd_soc_dai *cpu_dai, unsigned int fmt)
>  {
> @@ -98,7 +96,7 @@ static int imx_ssi_set_dai_fmt(struct snd_soc_dai *cpu_dai, unsigned int fmt)
>  	case SND_SOC_DAIFMT_I2S:
>  		/* data on rising edge of bclk, frame low 1clk before data */
>  		strcr |= SSI_STCR_TFSI | SSI_STCR_TEFS | SSI_STCR_TXBIT0;
> -		scr |= SSI_SCR_NET;
> +		scr |= SSI_SCR_NET | SSI_SCR_I2S_MODE_SLAVE;

You should also zero out the SSI_I2S_MODE_MASK in the scr = readl()...
above.
Otherwise I'm ok with this patch.

Sascha


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