[PATCH v2] ASoC: fsl_sai: Correct the clock source for mclk0

[Shengjiu Wang <shengjiu.wang@nxp.com>]

On VF610, mclk0 = bus_clk;
On i.MX6SX/6UL/6ULL/7D, mclk0 = mclk1;
On i.MX7ULP, mclk0 = bus_clk;
On i.MX8QM/8QXP, mclk0 = bus_clk;
On i.MX8MQ/8MN/8MM/8MP, mclk0 = bus_clk;

So add variable mclk0_is_mclk1 in fsl_sai_soc_data to
distinguish these platforms.

Signed-off-by: Shengjiu Wang <shengjiu.wang@nxp.com>
---
changes in v2:
- rename mclk0_mclk1_match to mclk0_is_mclk1
- skip MCLK0 when it is same as MCLK1 on master clock scanning

 sound/soc/fsl/fsl_sai.c | 20 ++++++++++++++++++--
 sound/soc/fsl/fsl_sai.h |  1 +
 2 files changed, 19 insertions(+), 2 deletions(-)

diff --git a/sound/soc/fsl/fsl_sai.c b/sound/soc/fsl/fsl_sai.c
index 3e5c1eaccd5e..f3d3d20d35d7 100644
--- a/sound/soc/fsl/fsl_sai.c
+++ b/sound/soc/fsl/fsl_sai.c
@@ -359,7 +359,14 @@ static int fsl_sai_set_bclk(struct snd_soc_dai *dai, bool tx, u32 freq)
 	if (sai->is_slave_mode)
 		return 0;
 
-	for (id = 0; id < FSL_SAI_MCLK_MAX; id++) {
+	/*
+	 * There is no point in polling MCLK0 if it is identical to MCLK1.
+	 * And given that MQS use case has to use MCLK1 though two clocks
+	 * are the same, we simply skip MCLK0 and start to find from MCLK1.
+	 */
+	id = sai->soc_data->mclk0_is_mclk1 ? 1 : 0;
+
+	for (; id < FSL_SAI_MCLK_MAX; id++) {
 		clk_rate = clk_get_rate(sai->mclk_clk[id]);
 		if (!clk_rate)
 			continue;
@@ -1040,7 +1047,6 @@ static int fsl_sai_probe(struct platform_device *pdev)
 		sai->bus_clk = NULL;
 	}
 
-	sai->mclk_clk[0] = sai->bus_clk;
 	for (i = 1; i < FSL_SAI_MCLK_MAX; i++) {
 		sprintf(tmp, "mclk%d", i);
 		sai->mclk_clk[i] = devm_clk_get(&pdev->dev, tmp);
@@ -1051,6 +1057,11 @@ static int fsl_sai_probe(struct platform_device *pdev)
 		}
 	}
 
+	if (sai->soc_data->mclk0_is_mclk1)
+		sai->mclk_clk[0] = sai->mclk_clk[1];
+	else
+		sai->mclk_clk[0] = sai->bus_clk;
+
 	irq = platform_get_irq(pdev, 0);
 	if (irq < 0)
 		return irq;
@@ -1165,6 +1176,7 @@ static const struct fsl_sai_soc_data fsl_sai_vf610_data = {
 	.use_edma = false,
 	.fifo_depth = 32,
 	.reg_offset = 0,
+	.mclk0_is_mclk1 = false,
 };
 
 static const struct fsl_sai_soc_data fsl_sai_imx6sx_data = {
@@ -1172,6 +1184,7 @@ static const struct fsl_sai_soc_data fsl_sai_imx6sx_data = {
 	.use_edma = false,
 	.fifo_depth = 32,
 	.reg_offset = 0,
+	.mclk0_is_mclk1 = true,
 };
 
 static const struct fsl_sai_soc_data fsl_sai_imx7ulp_data = {
@@ -1179,6 +1192,7 @@ static const struct fsl_sai_soc_data fsl_sai_imx7ulp_data = {
 	.use_edma = false,
 	.fifo_depth = 16,
 	.reg_offset = 8,
+	.mclk0_is_mclk1 = false,
 };
 
 static const struct fsl_sai_soc_data fsl_sai_imx8mq_data = {
@@ -1186,6 +1200,7 @@ static const struct fsl_sai_soc_data fsl_sai_imx8mq_data = {
 	.use_edma = false,
 	.fifo_depth = 128,
 	.reg_offset = 8,
+	.mclk0_is_mclk1 = false,
 };
 
 static const struct fsl_sai_soc_data fsl_sai_imx8qm_data = {
@@ -1193,6 +1208,7 @@ static const struct fsl_sai_soc_data fsl_sai_imx8qm_data = {
 	.use_edma = true,
 	.fifo_depth = 64,
 	.reg_offset = 0,
+	.mclk0_is_mclk1 = false,
 };
 
 static const struct of_device_id fsl_sai_ids[] = {
diff --git a/sound/soc/fsl/fsl_sai.h b/sound/soc/fsl/fsl_sai.h
index 4bbcd0dbe8f1..ff2619f1b214 100644
--- a/sound/soc/fsl/fsl_sai.h
+++ b/sound/soc/fsl/fsl_sai.h
@@ -219,6 +219,7 @@
 struct fsl_sai_soc_data {
 	bool use_imx_pcm;
 	bool use_edma;
+	bool mclk0_is_mclk1;
 	unsigned int fifo_depth;
 	unsigned int reg_offset;
 };
-- 
2.27.0