From 2f7c68cb55ecb7331f2381deb497c27155f32faf Mon Sep 17 00:00:00 2001
From: hc <hc@nodka.com>
Date: Wed, 03 Jan 2024 09:43:39 +0000
Subject: [PATCH] update kernel to 5.10.198

---
 kernel/sound/soc/jz4740/jz4740-i2s.c |   39 ++++++++++++++++++++++++++++++++++-----
 1 files changed, 34 insertions(+), 5 deletions(-)

diff --git a/kernel/sound/soc/jz4740/jz4740-i2s.c b/kernel/sound/soc/jz4740/jz4740-i2s.c
index 0793e28..fb6476b 100644
--- a/kernel/sound/soc/jz4740/jz4740-i2s.c
+++ b/kernel/sound/soc/jz4740/jz4740-i2s.c
@@ -59,7 +59,8 @@
 #define JZ_AIC_CTRL_MONO_TO_STEREO BIT(11)
 #define JZ_AIC_CTRL_SWITCH_ENDIANNESS BIT(10)
 #define JZ_AIC_CTRL_SIGNED_TO_UNSIGNED BIT(9)
-#define JZ_AIC_CTRL_FLUSH		BIT(8)
+#define JZ_AIC_CTRL_TFLUSH		BIT(8)
+#define JZ_AIC_CTRL_RFLUSH		BIT(7)
 #define JZ_AIC_CTRL_ENABLE_ROR_INT BIT(6)
 #define JZ_AIC_CTRL_ENABLE_TUR_INT BIT(5)
 #define JZ_AIC_CTRL_ENABLE_RFS_INT BIT(4)
@@ -94,6 +95,8 @@
 struct i2s_soc_info {
 	enum jz47xx_i2s_version version;
 	struct snd_soc_dai_driver *dai;
+
+	bool shared_fifo_flush;
 };
 
 struct jz4740_i2s {
@@ -122,19 +125,44 @@
 	writel(value, i2s->base + reg);
 }
 
+static inline void jz4740_i2s_set_bits(const struct jz4740_i2s *i2s,
+	unsigned int reg, uint32_t bits)
+{
+	uint32_t value = jz4740_i2s_read(i2s, reg);
+	value |= bits;
+	jz4740_i2s_write(i2s, reg, value);
+}
+
 static int jz4740_i2s_startup(struct snd_pcm_substream *substream,
 	struct snd_soc_dai *dai)
 {
 	struct jz4740_i2s *i2s = snd_soc_dai_get_drvdata(dai);
-	uint32_t conf, ctrl;
+	uint32_t conf;
 	int ret;
+
+	/*
+	 * When we can flush FIFOs independently, only flush the FIFO
+	 * that is starting up. We can do this when the DAI is active
+	 * because it does not disturb other active substreams.
+	 */
+	if (!i2s->soc_info->shared_fifo_flush) {
+		if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
+			jz4740_i2s_set_bits(i2s, JZ_REG_AIC_CTRL, JZ_AIC_CTRL_TFLUSH);
+		else
+			jz4740_i2s_set_bits(i2s, JZ_REG_AIC_CTRL, JZ_AIC_CTRL_RFLUSH);
+	}
 
 	if (snd_soc_dai_active(dai))
 		return 0;
 
-	ctrl = jz4740_i2s_read(i2s, JZ_REG_AIC_CTRL);
-	ctrl |= JZ_AIC_CTRL_FLUSH;
-	jz4740_i2s_write(i2s, JZ_REG_AIC_CTRL, ctrl);
+	/*
+	 * When there is a shared flush bit for both FIFOs, the TFLUSH
+	 * bit flushes both FIFOs. Flushing while the DAI is active would
+	 * cause FIFO underruns in other active substreams so we have to
+	 * guard this behind the snd_soc_dai_active() check.
+	 */
+	if (i2s->soc_info->shared_fifo_flush)
+		jz4740_i2s_set_bits(i2s, JZ_REG_AIC_CTRL, JZ_AIC_CTRL_TFLUSH);
 
 	ret = clk_prepare_enable(i2s->clk_i2s);
 	if (ret)
@@ -467,6 +495,7 @@
 static const struct i2s_soc_info jz4740_i2s_soc_info = {
 	.version = JZ_I2S_JZ4740,
 	.dai = &jz4740_i2s_dai,
+	.shared_fifo_flush = true,
 };
 
 static const struct i2s_soc_info jz4760_i2s_soc_info = {

--
Gitblit v1.6.2