ASoC: fsl_spdif: spba clk is needed by spdif device

SPDIF need to enable the spba clock, when sdma is using share peripheral
script. In this case, there is two spba master port is used, if don't
enable the clock, the spba bus will have arbitration issue, which may
cause read/write wrong data from/to SPDIF registers.

Signed-off-by: Shengjiu Wang <shengjiu.wang@freescale.com>
Acked-by: Nicolin Chen <nicoleotsuka@gmail.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

sound/soc/fsl/fsl_spdif.c

@@ -88,6 +88,7 @@ struct spdif_mixer_control {
  * @rxclk: rx clock sources for capture
  * @coreclk: core clock for register access via DMA
  * @sysclk: system clock for rx clock rate measurement
+ * @spbaclk: SPBA clock (optional, depending on SoC design)
  * @dma_params_tx: DMA parameters for transmit channel
  * @dma_params_rx: DMA parameters for receive channel
  */
@@ -106,6 +107,7 @@ struct fsl_spdif_priv {
 	struct clk *rxclk;
 	struct clk *coreclk;
 	struct clk *sysclk;
+	struct clk *spbaclk;
 	struct snd_dmaengine_dai_dma_data dma_params_tx;
 	struct snd_dmaengine_dai_dma_data dma_params_rx;
 	/* regcache for SRPC */
@@ -474,6 +476,14 @@ static int fsl_spdif_startup(struct snd_pcm_substream *substream,
 			return ret;
 		}
 
+		if (!IS_ERR(spdif_priv->spbaclk)) {
+			ret = clk_prepare_enable(spdif_priv->spbaclk);
+			if (ret) {
+				dev_err(&pdev->dev, "failed to enable spba clock\n");
+				goto err_spbaclk;
+			}
+		}
+
 		ret = spdif_softreset(spdif_priv);
 		if (ret) {
 			dev_err(&pdev->dev, "failed to soft reset\n");
@@ -515,6 +525,9 @@ disable_txclk:
 	for (i--; i >= 0; i--)
 		clk_disable_unprepare(spdif_priv->txclk[i]);
 err:
+	if (!IS_ERR(spdif_priv->spbaclk))
+		clk_disable_unprepare(spdif_priv->spbaclk);
+err_spbaclk:
 	clk_disable_unprepare(spdif_priv->coreclk);
 
 	return ret;
@@ -548,6 +561,8 @@ static void fsl_spdif_shutdown(struct snd_pcm_substream *substream,
 		spdif_intr_status_clear(spdif_priv);
 		regmap_update_bits(regmap, REG_SPDIF_SCR,
 				SCR_LOW_POWER, SCR_LOW_POWER);
+		if (!IS_ERR(spdif_priv->spbaclk))
+			clk_disable_unprepare(spdif_priv->spbaclk);
 		clk_disable_unprepare(spdif_priv->coreclk);
 	}
 }
@@ -1261,6 +1276,10 @@ static int fsl_spdif_probe(struct platform_device *pdev)
 		return PTR_ERR(spdif_priv->coreclk);
 	}
 
+	spdif_priv->spbaclk = devm_clk_get(&pdev->dev, "spba");
+	if (IS_ERR(spdif_priv->spbaclk))
+		dev_warn(&pdev->dev, "no spba clock in devicetree\n");
+
 	/* Select clock source for rx/tx clock */
 	spdif_priv->rxclk = devm_clk_get(&pdev->dev, "rxtx1");
 	if (IS_ERR(spdif_priv->rxclk)) {