linux-kernel - [PATCH] ASoC: samsung: i2s: Don't use register read to determine slave/master mode

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Date:   Tue, 19 Mar 2019 13:11:02 +0100
From:   Sylwester Nawrocki <s.nawrocki@...sung.com>
To:     broonie@...nel.org, lgirdwood@...il.com
Cc:     sbkim73@...sung.com, krzk@...nel.org, b.zolnierkie@...sung.com,
        m.szyprowski@...sung.com, alsa-devel@...a-project.org,
        linux-samsung-soc@...r.kernel.org, linux-kernel@...r.kernel.org,
        Sylwester Nawrocki <s.nawrocki@...sung.com>
Subject: [PATCH] ASoC: samsung: i2s: Don't use register read to determine
 slave/master mode

We can simplify the code by caching the CPU DAI master/slave
information rather than reading previously set register bit.

Signed-off-by: Sylwester Nawrocki <s.nawrocki@...sung.com>
---
 sound/soc/samsung/i2s.c | 27 +++++++++++----------------
 1 file changed, 11 insertions(+), 16 deletions(-)

diff --git a/sound/soc/samsung/i2s.c b/sound/soc/samsung/i2s.c
index ab471d550d17..9722940da6a4 100644
--- a/sound/soc/samsung/i2s.c
+++ b/sound/soc/samsung/i2s.c
@@ -88,12 +88,6 @@ struct samsung_i2s_priv {
 	struct platform_device *pdev;
 	struct platform_device *pdev_sec;
 
-	/* Memory mapped SFR region */
-	void __iomem *addr;
-
-	/* Spinlock protecting access to the device's registers */
-	spinlock_t lock;
-
 	/* Lock for cross interface checks */
 	spinlock_t pcm_lock;
 
@@ -122,6 +116,15 @@ struct samsung_i2s_priv {
 	/* The clock provider's data */
 	struct clk *clk_table[3];
 	struct clk_onecell_data clk_data;
+
+	/* Spinlock protecting member fields below */
+	spinlock_t lock;
+
+	/* Memory mapped SFR region */
+	void __iomem *addr;
+
+	/* A flag indicating the I2S slave mode operation */
+	bool slave_mode;
 };
 
 /* Returns true if this is the 'overlay' stereo DAI */
@@ -130,15 +133,6 @@ static inline bool is_secondary(struct i2s_dai *i2s)
 	return i2s->drv->id == SAMSUNG_I2S_ID_SECONDARY;
 }
 
-/* If operating in SoC-Slave mode */
-static inline bool is_slave(struct i2s_dai *i2s)
-{
-	struct samsung_i2s_priv *priv = i2s->priv;
-
-	u32 mod = readl(priv->addr + I2SMOD);
-	return (mod & (1 << priv->variant_regs->mss_off)) ? true : false;
-}
-
 /* If this interface of the controller is transmitting data */
 static inline bool tx_active(struct i2s_dai *i2s)
 {
@@ -715,6 +709,7 @@ static int i2s_set_fmt(struct snd_soc_dai *dai, unsigned int fmt)
 	mod &= ~(sdf_mask | lrp_rlow | mod_slave);
 	mod |= tmp;
 	writel(mod, priv->addr + I2SMOD);
+	priv->slave_mode = (mod & mod_slave);
 	spin_unlock_irqrestore(&priv->lock, flags);
 	pm_runtime_put(dai->dev);
 
@@ -917,7 +912,7 @@ static int config_setup(struct i2s_dai *i2s)
 	set_rfs(i2s, rfs);
 
 	/* Don't bother with PSR in Slave mode */
-	if (is_slave(i2s))
+	if (priv->slave_mode)
 		return 0;
 
 	if (!(priv->quirks & QUIRK_NO_MUXPSR)) {
-- 
2.17.1