On Wed, Jul 27, 2016 at 04:02:48PM -0700, Nicolin Chen wrote:

The codec driver should control the mclk. So this patch adds this support.

+	/* Check if MCLK provided */
+	rt5659->mclk = devm_clk_get(&i2c->dev, "mclk");
+	if (IS_ERR(rt5659->mclk)) {
+		if (PTR_ERR(rt5659->mclk) == -EPROBE_DEFER)
+			return -EPROBE_DEFER;
+		/* Otherwise mark the mclk pointer to NULL */
+		rt5659->mclk = NULL;
+	}

This device seems to be used on x86 systems so we'll need to ensure that
they register clocks for this.  They really should set this up using
quirks keyed off DMI information or similar so it's hidden from other
systems.