ASoC: rockchip: i2s: Fix concurrency between tx/rx

This patch adds lock to fix comcurrency between tx/rx
to fix 'rockchip-i2s ff070000.i2s; fail to clear'

Considering the situation;

       tx stream              rx stream
           |                      |
           |                   disable
         enable                   |
           |                    reset

After this patch:

         lock
           |
       tx stream
           |
         enable
           |
        unlock
       --------               ---------
                                lock
                                  |
                              rx stream
                                  |
                               disable
                                  |
                                reset
                                  |
                               unlock

Signed-off-by: Sugar Zhang <sugar.zhang@rock-chips.com>
Link: https://lore.kernel.org/r/1630674434-650-1-git-send-email-sugar.zhang@rock-chips.com
Signed-off-by: Mark Brown <broonie@kernel.org>

Author: Sugar Zhang

sound/soc/rockchip/rockchip_i2s.c

@@ -15,6 +15,7 @@
 #include <linux/clk.h>
 #include <linux/pm_runtime.h>
 #include <linux/regmap.h>
+#include <linux/spinlock.h>
 #include <sound/pcm_params.h>
 #include <sound/dmaengine_pcm.h>
 
@@ -53,6 +54,7 @@ struct rk_i2s_dev {
 	bool is_master_mode;
 	const struct rk_i2s_pins *pins;
 	unsigned int bclk_ratio;
+	spinlock_t lock; /* tx/rx lock */
 };
 
 static int i2s_runtime_suspend(struct device *dev)
@@ -96,6 +98,7 @@ static void rockchip_snd_txctrl(struct rk_i2s_dev *i2s, int on)
 	unsigned int val = 0;
 	int retry = 10;
 
+	spin_lock(&i2s->lock);
 	if (on) {
 		regmap_update_bits(i2s->regmap, I2S_DMACR,
 				   I2S_DMACR_TDE_ENABLE, I2S_DMACR_TDE_ENABLE);
@@ -136,13 +139,15 @@ static void rockchip_snd_txctrl(struct rk_i2s_dev *i2s, int on)
 			}
 		}
 	}
+	spin_unlock(&i2s->lock);
 }
 
 static void rockchip_snd_rxctrl(struct rk_i2s_dev *i2s, int on)
 {
 	unsigned int val = 0;
 	int retry = 10;
 
+	spin_lock(&i2s->lock);
 	if (on) {
 		regmap_update_bits(i2s->regmap, I2S_DMACR,
 				   I2S_DMACR_RDE_ENABLE, I2S_DMACR_RDE_ENABLE);
@@ -183,6 +188,7 @@ static void rockchip_snd_rxctrl(struct rk_i2s_dev *i2s, int on)
 			}
 		}
 	}
+	spin_unlock(&i2s->lock);
 }
 
 static int rockchip_i2s_set_fmt(struct snd_soc_dai *cpu_dai,
@@ -684,6 +690,7 @@ static int rockchip_i2s_probe(struct platform_device *pdev)
 	if (!i2s)
 		return -ENOMEM;
 
+	spin_lock_init(&i2s->lock);
 	i2s->dev = &pdev->dev;
 
 	i2s->grf = syscon_regmap_lookup_by_phandle(node, "rockchip,grf");