ASoC: fsl_asrc: spba clock is needed by asrc device

ASRC 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 ASRC 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,asrc.txt

@@ -25,6 +25,11 @@ Required properties:
 	"mem"		  Peripheral access clock to access registers.
 	"ipg"		  Peripheral clock to driver module.
 	"asrck_<0-f>"	  Clock sources for input and output clock.
+	"spba"		  The spba clock is required when ASRC 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.
 
    - big-endian		: If this property is absent, the little endian mode
 			  will be in use as default. Otherwise, the big endian

sound/soc/fsl/fsl_asrc.c

@@ -859,6 +859,10 @@ static int fsl_asrc_probe(struct platform_device *pdev)
 		return PTR_ERR(asrc_priv->ipg_clk);
 	}
 
+	asrc_priv->spba_clk = devm_clk_get(&pdev->dev, "spba");
+	if (IS_ERR(asrc_priv->spba_clk))
+		dev_warn(&pdev->dev, "failed to get spba clock\n");
+
 	for (i = 0; i < ASRC_CLK_MAX_NUM; i++) {
 		sprintf(tmp, "asrck_%x", i);
 		asrc_priv->asrck_clk[i] = devm_clk_get(&pdev->dev, tmp);
@@ -939,6 +943,11 @@ static int fsl_asrc_runtime_resume(struct device *dev)
 	ret = clk_prepare_enable(asrc_priv->ipg_clk);
 	if (ret)
 		goto disable_mem_clk;
+	if (!IS_ERR(asrc_priv->spba_clk)) {
+		ret = clk_prepare_enable(asrc_priv->spba_clk);
+		if (ret)
+			goto disable_ipg_clk;
+	}
 	for (i = 0; i < ASRC_CLK_MAX_NUM; i++) {
 		ret = clk_prepare_enable(asrc_priv->asrck_clk[i]);
 		if (ret)
@@ -950,6 +959,9 @@ static int fsl_asrc_runtime_resume(struct device *dev)
 disable_asrck_clk:
 	for (i--; i >= 0; i--)
 		clk_disable_unprepare(asrc_priv->asrck_clk[i]);
+	if (!IS_ERR(asrc_priv->spba_clk))
+		clk_disable_unprepare(asrc_priv->spba_clk);
+disable_ipg_clk:
 	clk_disable_unprepare(asrc_priv->ipg_clk);
 disable_mem_clk:
 	clk_disable_unprepare(asrc_priv->mem_clk);
@@ -963,6 +975,8 @@ static int fsl_asrc_runtime_suspend(struct device *dev)
 
 	for (i = 0; i < ASRC_CLK_MAX_NUM; i++)
 		clk_disable_unprepare(asrc_priv->asrck_clk[i]);
+	if (!IS_ERR(asrc_priv->spba_clk))
+		clk_disable_unprepare(asrc_priv->spba_clk);
 	clk_disable_unprepare(asrc_priv->ipg_clk);
 	clk_disable_unprepare(asrc_priv->mem_clk);
 

sound/soc/fsl/fsl_asrc.h

@@ -426,6 +426,7 @@ struct fsl_asrc_pair {
  * @paddr: physical address to the base address of registers
  * @mem_clk: clock source to access register
  * @ipg_clk: clock source to drive peripheral
+ * @spba_clk: SPBA clock (optional, depending on SoC design)
  * @asrck_clk: clock sources to driver ASRC internal logic
  * @lock: spin lock for resource protection
  * @pair: pair pointers
@@ -442,6 +443,7 @@ struct fsl_asrc {
 	unsigned long paddr;
 	struct clk *mem_clk;
 	struct clk *ipg_clk;
+	struct clk *spba_clk;
 	struct clk *asrck_clk[ASRC_CLK_MAX_NUM];
 	spinlock_t lock;