ASoC: fsl_ssi: Setup AC97 in fsl_ssi_hw_init()

AC97 configures most of registers earlier to start a communication
with CODECs in order to successfully initialize CODEC. Currently,
_fsl_ssi_set_dai_fmt() and fsl_ssi_setup_ac97() are called to get
all SSI registers properly set.

Since now the driver has a fsl_ssi_hw_init() to handle all register
initial settings, this patch moves those register settings of AC97
to the fsl_ssi_hw_init() as well.

Meanwhile it applies _fsl_ssi_set_dai_fmt() call to AC97 only since
other formats would be configured via normal set_dai_fmt() directly.

This patch also adds fsl_ssi_hw_clean() to cleanup control bits for
AC97 in the platform remote() function.

Signed-off-by: Nicolin Chen <nicoleotsuka@gmail.com>
Tested-by: Caleb Crome <caleb@crome.org>
Tested-by: Maciej S. Szmigiero <mail@maciej.szmigiero.name>
Reviewed-by: Maciej S. Szmigiero <mail@maciej.szmigiero.name>
Signed-off-by: Mark Brown <broonie@kernel.org>

sound/soc/fsl/fsl_ssi.c

@@ -987,9 +987,6 @@ static int _fsl_ssi_set_dai_fmt(struct device *dev,
 	regmap_write(regs, REG_SSI_SRCR, srcr);
 	regmap_write(regs, REG_SSI_SCR, scr);
 
-	if ((fmt & SND_SOC_DAIFMT_FORMAT_MASK) == SND_SOC_DAIFMT_AC97)
-		fsl_ssi_setup_ac97(ssi);
-
 	return 0;
 }
 
@@ -1255,9 +1252,33 @@ static int fsl_ssi_hw_init(struct fsl_ssi *ssi)
 		regmap_update_bits(ssi->regs, REG_SSI_SCR,
 				   SSI_SCR_TCH_EN, SSI_SCR_TCH_EN);
 
+	/* AC97 should start earlier to communicate with CODECs */
+	if (fsl_ssi_is_ac97(ssi)) {
+		_fsl_ssi_set_dai_fmt(ssi->dev, ssi, ssi->dai_fmt);
+		fsl_ssi_setup_ac97(ssi);
+	}
+
 	return 0;
 }
 
+/**
+ * Clear SSI registers
+ */
+static void fsl_ssi_hw_clean(struct fsl_ssi *ssi)
+{
+	/* Disable registers for AC97 */
+	if (fsl_ssi_is_ac97(ssi)) {
+		/* Disable TE and RE bits first */
+		regmap_update_bits(ssi->regs, REG_SSI_SCR,
+				   SSI_SCR_TE | SSI_SCR_RE, 0);
+		/* Disable AC97 mode */
+		regmap_write(ssi->regs, REG_SSI_SACNT, 0);
+		/* Unset WAIT bits */
+		regmap_write(ssi->regs, REG_SSI_SOR, 0);
+		/* Disable SSI -- software reset */
+		regmap_update_bits(ssi->regs, REG_SSI_SCR, SSI_SCR_SSIEN, 0);
+	}
+}
 /**
  * Make every character in a string lower-case
  */
@@ -1540,9 +1561,6 @@ static int fsl_ssi_probe(struct platform_device *pdev)
 	}
 
 done:
-	if (ssi->dai_fmt)
-		_fsl_ssi_set_dai_fmt(dev, ssi, ssi->dai_fmt);
-
 	/* Initially configures SSI registers */
 	fsl_ssi_hw_init(ssi);
 
@@ -1592,6 +1610,9 @@ static int fsl_ssi_remove(struct platform_device *pdev)
 	if (ssi->pdev)
 		platform_device_unregister(ssi->pdev);
 
+	/* Clean up SSI registers */
+	fsl_ssi_hw_clean(ssi);
+
 	if (ssi->soc->imx)
 		fsl_ssi_imx_clean(pdev, ssi);