sound: soc: xilinx: Call set_rate()

Instead of using the given clock rate, this patch is trying to set
the clock rate to specific audio frequency. With this patch,
the clock frequency doesn't have to be preconfigured to specific
frequency.

Signed-off-by: Hyun Kwon <[email protected]>
Signed-off-by: Michal Simek <[email protected]>

Author: xlnx-hyunkwon

sound/soc/xilinx/xilinx-dp-codec.c

@@ -30,6 +30,11 @@ struct xilinx_dp_codec {
 	struct clk *aud_clk;
 };
 
+struct xilinx_dp_codec_fmt {
+	unsigned long rate;
+	unsigned int snd_rate;
+};
+
 static struct snd_soc_dai_driver xilinx_dp_codec_dai = {
 	.name		= "xilinx-dp-snd-codec-dai",
 	.playback	= {
@@ -40,13 +45,26 @@ static struct snd_soc_dai_driver xilinx_dp_codec_dai = {
 	},
 };
 
+static const struct xilinx_dp_codec_fmt rates[] = {
+	{
+		.rate	= 48000 * 512,
+		.snd_rate = SNDRV_PCM_RATE_48000
+	},
+	{
+		.rate	= 44100 * 512,
+		.snd_rate = SNDRV_PCM_RATE_44100
+	}
+};
+
 static const struct snd_soc_codec_driver xilinx_dp_codec_codec_driver = {
 };
 
 static int xilinx_dp_codec_probe(struct platform_device *pdev)
 {
 	struct xilinx_dp_codec *codec;
-	int rate, ret;
+	unsigned int i;
+	unsigned long rate;
+	int ret;
 
 	codec = devm_kzalloc(&pdev->dev, sizeof(*codec), GFP_KERNEL);
 	if (!codec)
@@ -62,15 +80,24 @@ static int xilinx_dp_codec_probe(struct platform_device *pdev)
 		return ret;
 	}
 
-	rate = clk_get_rate(codec->aud_clk) / 512;
-	/* Ignore some offset */
-	rate = ALIGN(rate, 100);
-	if (rate == 44100) {
-		xilinx_dp_codec_dai.playback.rates = SNDRV_PCM_RATE_44100;
-	} else if (rate == 48000) {
-		xilinx_dp_codec_dai.playback.rates = SNDRV_PCM_RATE_48000;
-	} else {
+	for (i = 0; i < ARRAY_SIZE(rates); i++) {
+		clk_disable_unprepare(codec->aud_clk);
+		ret = clk_set_rate(codec->aud_clk, rates[i].rate);
+		clk_prepare_enable(codec->aud_clk);
+		if (ret)
+			continue;
+
+		rate = clk_get_rate(codec->aud_clk);
+		/* Ignore some offset +- 10 */
+		if (abs(rates[i].rate - rate) < 10) {
+			xilinx_dp_codec_dai.playback.rates = rates[i].snd_rate;
+			break;
+		}
 		ret = -EINVAL;
+	}
+
+	if (ret) {
+		dev_err(&pdev->dev, "Failed to get required clock freq\n");
 		goto error_clk;
 	}