[PATCH v3 4/4] ASoC: fsl_sai: Add AUDMIX mode support on i.MX952

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

One of SAI interfaces is connected to AUDMIX in the i.MX952 chip, but
AUDMIX can be bypassed or not bypassed on the i.MX952 platform.

There are three use cases:
1) SAI -> Codec (No AUDMIX between SAI and Codec)
2) SAI -> Codec (Has AUDMIX, but AUDMIX is bypassed)
3) SAI -> AUDMIX -> Codec (Has AUDMIX and used)

So add 'fsl,sai-amix-mode' property for this feature

fsl,sai-amix-mode = "none": is for case 1)
fsl,sai-amix-mode = "bypass": is for case 2)
fsl,sai-amix-mode = "audmix": is for case 3)

Signed-off-by: Shengjiu Wang <shengjiu.wang@nxp.com>
---
 include/linux/firmware/imx/sm.h |  2 ++
 sound/soc/fsl/fsl_sai.c         | 21 +++++++++++++++++++++
 sound/soc/fsl/fsl_sai.h         |  4 ++++
 3 files changed, 27 insertions(+)

diff --git a/include/linux/firmware/imx/sm.h b/include/linux/firmware/imx/sm.h
index a33b45027356..ba5d93bd6158 100644
--- a/include/linux/firmware/imx/sm.h
+++ b/include/linux/firmware/imx/sm.h
@@ -26,6 +26,8 @@
 #define SCMI_IMX94_CTRL_SAI3_MCLK	5U	/*!< WAKE SAI3 MCLK */
 #define SCMI_IMX94_CTRL_SAI4_MCLK	6U	/*!< WAKE SAI4 MCLK */
 
+#define SCMI_IMX952_CTRL_BYPASS_AUDMIX	8U      /* WAKE AUDMIX */
+
 #if IS_ENABLED(CONFIG_IMX_SCMI_MISC_DRV)
 int scmi_imx_misc_ctrl_get(u32 id, u32 *num, u32 *val);
 int scmi_imx_misc_ctrl_set(u32 id, u32 val);
diff --git a/sound/soc/fsl/fsl_sai.c b/sound/soc/fsl/fsl_sai.c
index 2fa14fbdfe1a..148e09e58dfa 100644
--- a/sound/soc/fsl/fsl_sai.c
+++ b/sound/soc/fsl/fsl_sai.c
@@ -7,6 +7,7 @@
 #include <linux/clk.h>
 #include <linux/delay.h>
 #include <linux/dmaengine.h>
+#include <linux/firmware/imx/sm.h>
 #include <linux/module.h>
 #include <linux/of.h>
 #include <linux/pinctrl/consumer.h>
@@ -1425,10 +1426,12 @@ static int fsl_sai_probe(struct platform_device *pdev)
 	struct fsl_sai *sai;
 	struct regmap *gpr;
 	void __iomem *base;
+	const char *str = NULL;
 	char tmp[8];
 	int irq, ret, i;
 	int index;
 	u32 dmas[4];
+	u32 val;
 
 	sai = devm_kzalloc(dev, sizeof(*sai), GFP_KERNEL);
 	if (!sai)
@@ -1598,6 +1601,24 @@ static int fsl_sai_probe(struct platform_device *pdev)
 	if (ret < 0 && ret != -ENOSYS)
 		goto err_pm_get_sync;
 
+	if (of_device_is_compatible(np, "fsl,imx952-sai") &&
+	    !of_property_read_string(np, "fsl,sai-amix-mode", &str)) {
+		if (!strcmp(str, "bypass"))
+			val = FSL_SAI_AMIX_BYPASS;
+		else if (!strcmp(str, "audmix"))
+			val = FSL_SAI_AMIX_AUDMIX;
+		else
+			val = FSL_SAI_AMIX_NONE;
+
+		if (val < FSL_SAI_AMIX_NONE) {
+			ret = scmi_imx_misc_ctrl_set(SCMI_IMX952_CTRL_BYPASS_AUDMIX, val);
+			if (ret) {
+				dev_err_probe(dev, ret, "Error setting audmix mode\n");
+				goto err_pm_get_sync;
+			}
+		}
+	}
+
 	/*
 	 * Register platform component before registering cpu dai for there
 	 * is not defer probe for platform component in snd_soc_add_pcm_runtime().
diff --git a/sound/soc/fsl/fsl_sai.h b/sound/soc/fsl/fsl_sai.h
index 6c917f79c6b0..7605cbaca3d8 100644
--- a/sound/soc/fsl/fsl_sai.h
+++ b/sound/soc/fsl/fsl_sai.h
@@ -230,6 +230,10 @@
 #define FSL_SAI_DL_I2S		BIT(0)
 #define FSL_SAI_DL_PDM		BIT(1)
 
+#define FSL_SAI_AMIX_BYPASS	0
+#define FSL_SAI_AMIX_AUDMIX	1
+#define FSL_SAI_AMIX_NONE	2
+
 struct fsl_sai_soc_data {
 	bool use_imx_pcm;
 	bool use_edma;
-- 
2.34.1