[PATCH v4 2/3] ASoC: qcom: q6apm-lpass-dais: Add MI2S clock control

[Mohammad Rafi Shaik]

Add support for MI2S clock control within q6apm-lpass DAIs, including
handling of MCLK, BCLK, and ECLK via the DAI .set_sysclk callback.
Each MI2S port now retrieves its clock handles from the device tree,
allowing per-port clock configuration and proper enable/disable during
startup and shutdown.

Co-developed-by: Srinivas Kandagatla <srinivas.kandagatla@xxxxxxxxxxxxxxxx>
Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@xxxxxxxxxxxxxxxx>
Tested-by: Neil Armstrong <neil.armstrong@xxxxxxxxxx>
Signed-off-by: Mohammad Rafi Shaik <mohammad.rafi.shaik@xxxxxxxxxxxxxxxx>
---
 sound/soc/qcom/qdsp6/q6apm-lpass-dais.c | 193 +++++++++++++++++++++++-
 sound/soc/qcom/qdsp6/q6prm.h            |   4 +
 2 files changed, 194 insertions(+), 3 deletions(-)

diff --git a/sound/soc/qcom/qdsp6/q6apm-lpass-dais.c b/sound/soc/qcom/qdsp6/q6apm-lpass-dais.c
index 006b283484d9..5743586ffda1 100644
--- a/sound/soc/qcom/qdsp6/q6apm-lpass-dais.c
+++ b/sound/soc/qcom/qdsp6/q6apm-lpass-dais.c
@@ -2,10 +2,12 @@
 // Copyright (c) 2021, Linaro Limited
 
 #include <dt-bindings/sound/qcom,q6dsp-lpass-ports.h>
+#include <linux/clk.h>
 #include <linux/err.h>
 #include <linux/init.h>
 #include <linux/module.h>
 #include <linux/device.h>
+#include <linux/of.h>
 #include <linux/platform_device.h>
 #include <linux/slab.h>
 #include <sound/pcm.h>
@@ -15,15 +17,64 @@
 #include "q6dsp-common.h"
 #include "audioreach.h"
 #include "q6apm.h"
+#include "q6prm.h"
 
 #define AUDIOREACH_BE_PCM_BASE	16
 
+struct q6apm_dai_priv_data {
+	struct clk *mclk;
+	struct clk *bclk;
+	struct clk *eclk;
+	bool mclk_enabled, bclk_enabled, eclk_enabled;
+};
+
 struct q6apm_lpass_dai_data {
 	struct q6apm_graph *graph[APM_PORT_MAX];
 	bool is_port_started[APM_PORT_MAX];
 	struct audioreach_module_config module_config[APM_PORT_MAX];
+	struct q6apm_dai_priv_data priv[APM_PORT_MAX];
 };
 
+static void q6apm_lpass_dai_disable_clocks(struct q6apm_lpass_dai_data *dai_data, int id)
+{
+	if (dai_data->priv[id].mclk_enabled) {
+		clk_disable_unprepare(dai_data->priv[id].mclk);
+		dai_data->priv[id].mclk_enabled = false;
+	}
+
+	if (dai_data->priv[id].bclk_enabled) {
+		clk_disable_unprepare(dai_data->priv[id].bclk);
+		dai_data->priv[id].bclk_enabled = false;
+	}
+
+	if (dai_data->priv[id].eclk_enabled) {
+		clk_disable_unprepare(dai_data->priv[id].eclk);
+		dai_data->priv[id].eclk_enabled = false;
+	}
+}
+
+static void q6apm_lpass_dai_put_clocks(struct q6apm_lpass_dai_data *dai_data)
+{
+	int i;
+
+	for (i = 0; i < APM_PORT_MAX; i++) {
+		q6apm_lpass_dai_disable_clocks(dai_data, i);
+
+		if (dai_data->priv[i].mclk) {
+			clk_put(dai_data->priv[i].mclk);
+			dai_data->priv[i].mclk = NULL;
+		}
+		if (dai_data->priv[i].bclk) {
+			clk_put(dai_data->priv[i].bclk);
+			dai_data->priv[i].bclk = NULL;
+		}
+		if (dai_data->priv[i].eclk) {
+			clk_put(dai_data->priv[i].eclk);
+			dai_data->priv[i].eclk = NULL;
+		}
+	}
+}
+
 static int q6dma_set_channel_map(struct snd_soc_dai *dai,
 				 unsigned int tx_num,
 				 const unsigned int *tx_ch_mask,
@@ -251,6 +302,66 @@ static int q6apm_lpass_dai_startup(struct snd_pcm_substream *substream, struct s
 	return 0;
 }
 
+static int q6i2s_dai_startup(struct snd_pcm_substream *substream, struct snd_soc_dai *dai)
+{
+	return q6apm_lpass_dai_startup(substream, dai);
+}
+
+static void q6i2s_lpass_dai_shutdown(struct snd_pcm_substream *substream, struct snd_soc_dai *dai)
+{
+	struct q6apm_lpass_dai_data *dai_data = dev_get_drvdata(dai->dev);
+
+	q6apm_lpass_dai_shutdown(substream, dai);
+	q6apm_lpass_dai_disable_clocks(dai_data, dai->id);
+}
+
+static int q6i2s_set_sysclk(struct snd_soc_dai *dai, int clk_id, unsigned int freq, int dir)
+{
+	struct q6apm_lpass_dai_data *dai_data = dev_get_drvdata(dai->dev);
+	struct clk *sysclk = NULL;
+	bool *enabled = NULL;
+	int ret = 0;
+
+	switch (clk_id) {
+	case LPAIF_MI2S_MCLK:
+		sysclk = dai_data->priv[dai->id].mclk;
+		enabled = &dai_data->priv[dai->id].mclk_enabled;
+		break;
+	case LPAIF_MI2S_BCLK:
+		sysclk = dai_data->priv[dai->id].bclk;
+		enabled = &dai_data->priv[dai->id].bclk_enabled;
+		break;
+	case LPAIF_MI2S_ECLK:
+		sysclk = dai_data->priv[dai->id].eclk;
+		enabled = &dai_data->priv[dai->id].eclk_enabled;
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	if (sysclk) {
+		ret = clk_set_rate(sysclk, freq);
+		if (ret) {
+			dev_err(dai->dev, "Error, Unable to set rate (%d) for sysclk %d\n",
+				freq, clk_id);
+			return ret;
+		}
+
+		if (*enabled)
+			return 0;
+
+		ret = clk_prepare_enable(sysclk);
+		if (ret) {
+			dev_err(dai->dev, "Error, Unable to prepare (%d) sysclk\n", clk_id);
+			return ret;
+		}
+
+		*enabled = true;
+	}
+
+	return ret;
+}
+
 static int q6i2s_set_fmt(struct snd_soc_dai *dai, unsigned int fmt)
 {
 	struct q6apm_lpass_dai_data *dai_data = dev_get_drvdata(dai->dev);
@@ -272,11 +383,12 @@ static const struct snd_soc_dai_ops q6dma_ops = {
 
 static const struct snd_soc_dai_ops q6i2s_ops = {
 	.prepare	= q6apm_lpass_dai_prepare,
-	.startup	= q6apm_lpass_dai_startup,
-	.shutdown	= q6apm_lpass_dai_shutdown,
+	.startup	= q6i2s_dai_startup,
+	.shutdown	= q6i2s_lpass_dai_shutdown,
 	.set_channel_map  = q6dma_set_channel_map,
 	.hw_params        = q6dma_hw_params,
 	.set_fmt	= q6i2s_set_fmt,
+	.set_sysclk	= q6i2s_set_sysclk,
 	.trigger	= q6apm_lpass_dai_trigger,
 };
 
@@ -297,6 +409,65 @@ static const struct snd_soc_component_driver q6apm_lpass_dai_component = {
 	.remove_order   = SND_SOC_COMP_ORDER_FIRST,
 };
 
+static int of_q6apm_parse_dai_data(struct device *dev,
+				   struct q6apm_lpass_dai_data *data)
+{
+	int ret;
+
+	for_each_child_of_node_scoped(dev->of_node, node) {
+		struct q6apm_dai_priv_data *priv;
+		int id;
+
+		ret = of_property_read_u32(node, "reg", &id);
+		if (ret || id < 0 || id >= APM_PORT_MAX) {
+			dev_err(dev, "valid dai id not found:%d\n", ret);
+			continue;
+		}
+
+		switch (id) {
+		/* MI2S specific properties */
+		case PRIMARY_MI2S_RX ... QUATERNARY_MI2S_TX:
+		case QUINARY_MI2S_RX ... QUINARY_MI2S_TX:
+		case SENARY_MI2S_RX ... SENARY_MI2S_TX:
+			priv = &data->priv[id];
+			priv->mclk = of_clk_get_by_name(node, "mclk");
+			if (IS_ERR(priv->mclk)) {
+				if (PTR_ERR(priv->mclk) == -EPROBE_DEFER) {
+					q6apm_lpass_dai_put_clocks(data);
+					return dev_err_probe(dev, PTR_ERR(priv->mclk),
+							     "unable to get mi2s mclk\n");
+				}
+				priv->mclk = NULL;
+			}
+
+			priv->bclk = of_clk_get_by_name(node, "bclk");
+			if (IS_ERR(priv->bclk)) {
+				if (PTR_ERR(priv->bclk) == -EPROBE_DEFER) {
+					q6apm_lpass_dai_put_clocks(data);
+					return dev_err_probe(dev, PTR_ERR(priv->bclk),
+							     "unable to get mi2s bclk\n");
+				}
+				priv->bclk = NULL;
+			}
+
+			priv->eclk = of_clk_get_by_name(node, "eclk");
+			if (IS_ERR(priv->eclk)) {
+				if (PTR_ERR(priv->eclk) == -EPROBE_DEFER) {
+					q6apm_lpass_dai_put_clocks(data);
+					return dev_err_probe(dev, PTR_ERR(priv->eclk),
+							     "unable to get mi2s eclk\n");
+				}
+				priv->eclk = NULL;
+			}
+			break;
+		default:
+			break;
+		}
+	}
+
+	return 0;
+}
+
 static int q6apm_lpass_dai_dev_probe(struct platform_device *pdev)
 {
 	struct q6dsp_audio_port_dai_driver_config cfg;
@@ -304,12 +475,16 @@ static int q6apm_lpass_dai_dev_probe(struct platform_device *pdev)
 	struct snd_soc_dai_driver *dais;
 	struct device *dev = &pdev->dev;
 	int num_dais;
+	int ret;
 
 	dai_data = devm_kzalloc(dev, sizeof(*dai_data), GFP_KERNEL);
 	if (!dai_data)
 		return -ENOMEM;
 
 	dev_set_drvdata(dev, dai_data);
+	ret = of_q6apm_parse_dai_data(dev, dai_data);
+	if (ret)
+		return ret;
 
 	memset(&cfg, 0, sizeof(cfg));
 	cfg.q6i2s_ops = &q6i2s_ops;
@@ -317,7 +492,18 @@ static int q6apm_lpass_dai_dev_probe(struct platform_device *pdev)
 	cfg.q6hdmi_ops = &q6hdmi_ops;
 	dais = q6dsp_audio_ports_set_config(dev, &cfg, &num_dais);
 
-	return devm_snd_soc_register_component(dev, &q6apm_lpass_dai_component, dais, num_dais);
+	ret = devm_snd_soc_register_component(dev, &q6apm_lpass_dai_component, dais, num_dais);
+	if (ret)
+		q6apm_lpass_dai_put_clocks(dai_data);
+
+	return ret;
+}
+
+static void q6apm_lpass_dai_dev_remove(struct platform_device *pdev)
+{
+	struct q6apm_lpass_dai_data *dai_data = dev_get_drvdata(&pdev->dev);
+
+	q6apm_lpass_dai_put_clocks(dai_data);
 }
 
 #ifdef CONFIG_OF
@@ -334,6 +520,7 @@ static struct platform_driver q6apm_lpass_dai_platform_driver = {
 		.of_match_table = of_match_ptr(q6apm_lpass_dai_device_id),
 	},
 	.probe = q6apm_lpass_dai_dev_probe,
+	.remove = q6apm_lpass_dai_dev_remove,
 };
 module_platform_driver(q6apm_lpass_dai_platform_driver);
 
diff --git a/sound/soc/qcom/qdsp6/q6prm.h b/sound/soc/qcom/qdsp6/q6prm.h
index a988a32086fe..bbbe6d368a41 100644
--- a/sound/soc/qcom/qdsp6/q6prm.h
+++ b/sound/soc/qcom/qdsp6/q6prm.h
@@ -3,6 +3,10 @@
 #ifndef __Q6PRM_H__
 #define __Q6PRM_H__
 
+#define LPAIF_MI2S_MCLK 1
+#define LPAIF_MI2S_BCLK 2
+#define LPAIF_MI2S_ECLK 3
+
 /* Clock ID for Primary I2S IBIT */
 #define Q6PRM_LPASS_CLK_ID_PRI_MI2S_IBIT                          0x100
 /* Clock ID for Primary I2S EBIT */
-- 
2.34.1