ASoC: fsl_ssi: Clean up set_dai_tdm_slot()

This patch replaces the register read with ssi->i2s_net for
simplification. It also removes masking SSIEN from scr value
since it's handled later by regmap_update_bits() to set this
scr value back.
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

@@ -1055,9 +1055,7 @@ static int fsl_ssi_set_dai_tdm_slot(struct snd_soc_dai *dai, u32 tx_mask,
 	}
 
 	/* The slot number should be >= 2 if using Network mode or I2S mode */
-	regmap_read(regs, REG_SSI_SCR, &val);
-	val &= SSI_SCR_I2S_MODE_MASK | SSI_SCR_NET;
-	if (val && slots < 2) {
+	if (ssi->i2s_net && slots < 2) {
 		dev_err(dai->dev, "slot number should be >= 2 in I2S or NET\n");
 		return -EINVAL;
 	}
@@ -1067,9 +1065,8 @@ static int fsl_ssi_set_dai_tdm_slot(struct snd_soc_dai *dai, u32 tx_mask,
 	regmap_update_bits(regs, REG_SSI_SRCCR,
 			   SSI_SxCCR_DC_MASK, SSI_SxCCR_DC(slots));
 
-	/* Save SSIEN bit of the SCR register */
+	/* Save the SCR register value */
 	regmap_read(regs, REG_SSI_SCR, &val);
-	val &= SSI_SCR_SSIEN;
 	/* Temporarily enable SSI to allow SxMSKs to be configurable */
 	regmap_update_bits(regs, REG_SSI_SCR, SSI_SCR_SSIEN, SSI_SCR_SSIEN);