ASoC: fsl_esai: spba clock is needed by esai device

ESAI 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 ESAI 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>

Documentation/devicetree/bindings/sound/fsl,esai.txt

@@ -27,6 +27,11 @@ Required properties:
 			  derive HCK, SCK and FS.
 	"fsys"		  The system clock derived from ahb clock used to
 			  derive HCK, SCK and FS.
+	"spba"		  The spba clock is required when ESAI is placed as a
+			  bus slave of the Shared Peripheral Bus and when two
+			  or more bus masters (CPU, DMA or DSP) try to access
+			  it. This property is optional depending on the SoC
+			  design.
 
   - fsl,fifo-depth	: The number of elements in the transmit and receive
 			  FIFOs. This number is the maximum allowed value for

sound/soc/fsl/fsl_esai.c

@@ -35,6 +35,7 @@
  * @coreclk: clock source to access register
  * @extalclk: esai clock source to derive HCK, SCK and FS
  * @fsysclk: system clock source to derive HCK, SCK and FS
+ * @spbaclk: SPBA clock (optional, depending on SoC design)
  * @fifo_depth: depth of tx/rx FIFO
  * @slot_width: width of each DAI slot
  * @slots: number of slots
@@ -54,6 +55,7 @@ struct fsl_esai {
 	struct clk *coreclk;
 	struct clk *extalclk;
 	struct clk *fsysclk;
+	struct clk *spbaclk;
 	u32 fifo_depth;
 	u32 slot_width;
 	u32 slots;
@@ -469,6 +471,11 @@ static int fsl_esai_startup(struct snd_pcm_substream *substream,
 	ret = clk_prepare_enable(esai_priv->coreclk);
 	if (ret)
 		return ret;
+	if (!IS_ERR(esai_priv->spbaclk)) {
+		ret = clk_prepare_enable(esai_priv->spbaclk);
+		if (ret)
+			goto err_spbaclk;
+	}
 	if (!IS_ERR(esai_priv->extalclk)) {
 		ret = clk_prepare_enable(esai_priv->extalclk);
 		if (ret)
@@ -499,6 +506,9 @@ err_fsysclk:
 	if (!IS_ERR(esai_priv->extalclk))
 		clk_disable_unprepare(esai_priv->extalclk);
 err_extalck:
+	if (!IS_ERR(esai_priv->spbaclk))
+		clk_disable_unprepare(esai_priv->spbaclk);
+err_spbaclk:
 	clk_disable_unprepare(esai_priv->coreclk);
 
 	return ret;
@@ -564,6 +574,8 @@ static void fsl_esai_shutdown(struct snd_pcm_substream *substream,
 		clk_disable_unprepare(esai_priv->fsysclk);
 	if (!IS_ERR(esai_priv->extalclk))
 		clk_disable_unprepare(esai_priv->extalclk);
+	if (!IS_ERR(esai_priv->spbaclk))
+		clk_disable_unprepare(esai_priv->spbaclk);
 	clk_disable_unprepare(esai_priv->coreclk);
 }
 
@@ -819,6 +831,11 @@ static int fsl_esai_probe(struct platform_device *pdev)
 		dev_warn(&pdev->dev, "failed to get fsys clock: %ld\n",
 				PTR_ERR(esai_priv->fsysclk));
 
+	esai_priv->spbaclk = devm_clk_get(&pdev->dev, "spba");
+	if (IS_ERR(esai_priv->spbaclk))
+		dev_warn(&pdev->dev, "failed to get spba clock: %ld\n",
+				PTR_ERR(esai_priv->spbaclk));
+
 	irq = platform_get_irq(pdev, 0);
 	if (irq < 0) {
 		dev_err(&pdev->dev, "no irq for node %s\n", pdev->name);