From 130c994af34ca5aeaee259ed14eddc419334b5c0 Mon Sep 17 00:00:00 2001
From: Sugar Zhang <sugar.zhang@rock-chips.com>
Date: Thu, 29 Nov 2018 11:34:33 +0800
Subject: [PATCH] ASoC: rockchip: i2s: Add reset mechanism

This patch brings i2s back to normal by resetting i2s m/h
logic if i2s' clear operation is failed.

Change-Id: I2fd47039b522ac89499b4a2912d5ffb7a469e75e
Signed-off-by: Sugar Zhang <sugar.zhang@rock-chips.com>
---
 sound/soc/rockchip/rockchip_i2s.c | 27 +++++++++++++++++++++++++--
 1 file changed, 25 insertions(+), 2 deletions(-)

diff --git a/sound/soc/rockchip/rockchip_i2s.c b/sound/soc/rockchip/rockchip_i2s.c
index 131339a9e512..010529c96add 100644
--- a/sound/soc/rockchip/rockchip_i2s.c
+++ b/sound/soc/rockchip/rockchip_i2s.c
@@ -18,6 +18,7 @@
 #include <linux/clk.h>
 #include <linux/pm_runtime.h>
 #include <linux/regmap.h>
+#include <linux/reset.h>
 #include <linux/spinlock.h>
 #include <sound/pcm_params.h>
 #include <sound/dmaengine_pcm.h>
@@ -42,6 +43,8 @@ struct rk_i2s_dev {
 
 	struct regmap *regmap;
 	struct regmap *grf;
+	struct reset_control *reset_m;
+	struct reset_control *reset_h;
 
 /*
  * Used to indicate the tx/rx status.
@@ -95,6 +98,21 @@ static inline struct rk_i2s_dev *to_info(struct snd_soc_dai *dai)
 	return snd_soc_dai_get_drvdata(dai);
 }
 
+static void rockchip_i2s_reset(struct rk_i2s_dev *i2s)
+{
+	if (!IS_ERR(i2s->reset_m))
+		reset_control_assert(i2s->reset_m);
+	if (!IS_ERR(i2s->reset_h))
+		reset_control_assert(i2s->reset_h);
+	udelay(1);
+	if (!IS_ERR(i2s->reset_m))
+		reset_control_deassert(i2s->reset_m);
+	if (!IS_ERR(i2s->reset_h))
+		reset_control_deassert(i2s->reset_h);
+	regcache_mark_dirty(i2s->regmap);
+	regcache_sync(i2s->regmap);
+}
+
 static void rockchip_snd_txctrl(struct rk_i2s_dev *i2s, int on)
 {
 	unsigned int val = 0;
@@ -135,7 +153,8 @@ static void rockchip_snd_txctrl(struct rk_i2s_dev *i2s, int on)
 				regmap_read(i2s->regmap, I2S_CLR, &val);
 				retry--;
 				if (!retry) {
-					dev_warn(i2s->dev, "fail to clear\n");
+					dev_warn(i2s->dev, "reset\n");
+					rockchip_i2s_reset(i2s);
 					break;
 				}
 			}
@@ -184,7 +203,8 @@ static void rockchip_snd_rxctrl(struct rk_i2s_dev *i2s, int on)
 				regmap_read(i2s->regmap, I2S_CLR, &val);
 				retry--;
 				if (!retry) {
-					dev_warn(i2s->dev, "fail to clear\n");
+					dev_warn(i2s->dev, "reset\n");
+					rockchip_i2s_reset(i2s);
 					break;
 				}
 			}
@@ -612,6 +632,9 @@ static int rockchip_i2s_probe(struct platform_device *pdev)
 		i2s->pins = of_id->data;
 	}
 
+	i2s->reset_m = devm_reset_control_get(&pdev->dev, "reset-m");
+	i2s->reset_h = devm_reset_control_get(&pdev->dev, "reset-h");
+
 	/* try to prepare related clocks */
 	i2s->hclk = devm_clk_get(&pdev->dev, "i2s_hclk");
 	if (IS_ERR(i2s->hclk)) {