ASoC: fsl-ssi: Support for SND_SOC_DAIFMT_CBM_CFS

Add SND_SOC_DAIFMT_CBM_CFS support for Freescale architecture.
Successfully tested on i.MX 6Quad Wandboard and UDOO boards connected to
the pcm1792a codec.
In CBM_CFS mode, when using a sample size of 16 bits, we cannot use
CCSR_SSI_SCR_I2S_MODE_MASTER since we get a frame sync every 16 bits.

Signed-off-by: Michael Trimarchi <[e-mail]>
Signed-off-by: Fabio Falzoi <[e-mail]>
Tested-by: Angelo Adamo <[e-mail]>
Acked-by: Timur Tabi <[e-mail]>
Signed-off-by: Mark Brown <[e-mail]>

sound/soc/fsl/fsl_ssi.c

···
 		SND_SOC_DAIFMT_CBS_CFS;
 }
 
+static bool fsl_ssi_is_i2s_cbm_cfs(struct fsl_ssi_private *ssi_private)
+{
+	return (ssi_private->dai_fmt & SND_SOC_DAIFMT_MASTER_MASK) ==
+		SND_SOC_DAIFMT_CBM_CFS;
+}
 /**
  * fsl_ssi_isr: SSI interrupt handler
  *
···
 		}
 	}
 
+	if (!fsl_ssi_is_ac97(ssi_private)) {
+		u8 i2smode;
+		/*
+		 * Switch to normal net mode in order to have a frame sync
+		 * signal every 32 bits instead of 16 bits
+		 */
+		if (fsl_ssi_is_i2s_cbm_cfs(ssi_private) && sample_size == 16)
+			i2smode = CCSR_SSI_SCR_I2S_MODE_NORMAL |
+				CCSR_SSI_SCR_NET;
+		else
+			i2smode = ssi_private->i2s_mode;
+
+		regmap_update_bits(regs, CCSR_SSI_SCR,
+				CCSR_SSI_SCR_NET | CCSR_SSI_SCR_I2S_MODE_MASK,
+				channels == 1 ? 0 : i2smode);
+	}
+
 	/*
 	 * FIXME: The documentation says that SxCCR[WL] should not be
 	 * modified while the SSI is enabled.  The only time this can
···
 	else
 		regmap_update_bits(regs, CCSR_SSI_SRCCR, CCSR_SSI_SxCCR_WL_MASK,
 				wl);
-
-	if (!fsl_ssi_is_ac97(ssi_private))
-		regmap_update_bits(regs, CCSR_SSI_SCR,
-				CCSR_SSI_SCR_NET | CCSR_SSI_SCR_I2S_MODE_MASK,
-				channels == 1 ? 0 : ssi_private->i2s_mode);
 
 	return 0;
 }
···
 	switch (fmt & SND_SOC_DAIFMT_FORMAT_MASK) {
 	case SND_SOC_DAIFMT_I2S:
 		switch (fmt & SND_SOC_DAIFMT_MASTER_MASK) {
+		case SND_SOC_DAIFMT_CBM_CFS:
 		case SND_SOC_DAIFMT_CBS_CFS:
 			ssi_private->i2s_mode |= CCSR_SSI_SCR_I2S_MODE_MASTER;
 			regmap_update_bits(regs, CCSR_SSI_STCCR,
···
 		scr |= CCSR_SSI_SCR_SYS_CLK_EN;
 		break;
 	case SND_SOC_DAIFMT_CBM_CFM:
+		scr &= ~CCSR_SSI_SCR_SYS_CLK_EN;
+		break;
+	case SND_SOC_DAIFMT_CBM_CFS:
+		strcr &= ~CCSR_SSI_STCR_TXDIR;
+		strcr |= CCSR_SSI_STCR_TFDIR;
 		scr &= ~CCSR_SSI_SCR_SYS_CLK_EN;
 		break;
 	default: