[PATCH 1/5] ASoC: mediatek: mt8195: add reset controller

[Trevor Wu]

Audio hardware is possibly used in the firmware stage, so resetting audio
hardware before regcache records default register values is required.

Signed-off-by: Trevor Wu <trevor.wu@xxxxxxxxxxxx>
---
 sound/soc/mediatek/mt8195/mt8195-afe-pcm.c | 16 ++++++++++++++++
 1 file changed, 16 insertions(+)

diff --git a/sound/soc/mediatek/mt8195/mt8195-afe-pcm.c b/sound/soc/mediatek/mt8195/mt8195-afe-pcm.c
index 550636500949..72b2c6d629b9 100644
--- a/sound/soc/mediatek/mt8195/mt8195-afe-pcm.c
+++ b/sound/soc/mediatek/mt8195/mt8195-afe-pcm.c
@@ -16,6 +16,7 @@
 #include <linux/of_platform.h>
 #include <linux/of_reserved_mem.h>
 #include <linux/pm_runtime.h>
+#include <linux/reset.h>
 #include "mt8195-afe-common.h"
 #include "mt8195-afe-clk.h"
 #include "mt8195-reg.h"
@@ -3056,6 +3057,7 @@ static int mt8195_afe_pcm_dev_probe(struct platform_device *pdev)
 	struct mtk_base_afe *afe;
 	struct mt8195_afe_private *afe_priv;
 	struct device *dev = &pdev->dev;
+	struct reset_control *rstc;
 	int i, irq_id, ret;
 	struct snd_soc_component *component;
 
@@ -3092,6 +3094,20 @@ static int mt8195_afe_pcm_dev_probe(struct platform_device *pdev)
 		return ret;
 	}
 
+	/* reset controller to reset audio regs before regmap cache */
+	rstc = devm_reset_control_get_exclusive(dev, "audiosys");
+	if (IS_ERR(rstc)) {
+		ret = PTR_ERR(rstc);
+		dev_err(dev, "could not get audiosys reset:%d\n", ret);
+		return ret;
+	}
+
+	ret = reset_control_reset(rstc);
+	if (ret) {
+		dev_err(dev, "failed to trigger audio reset:%d\n", ret);
+		return ret;
+	}
+
 	spin_lock_init(&afe_priv->afe_ctrl_lock);
 
 	mutex_init(&afe->irq_alloc_lock);
-- 
2.18.0