ASoC: Add WM9090 amplifier driver

The WM9090 is a high performance low power audio subsystem, including
headphone and class D speaker drivers.

Note that this driver is a standalone CODEC driver and so is only
immediately suitable for use with the WM9090 as a standalone sound card
taking line inputs, or with a DAC with no software control.  The pending
ASoC multi-CODEC support will expand the range of systems that can use
the driver, or system-specific adaptations can be made.

Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Acked-by: Liam Girdwood <lrg@slimlogic.co.uk>

include/sound/wm9090.h

@@ -0,0 +1,28 @@
+/*
+ * linux/sound/wm9090.h -- Platform data for WM9090
+ *
+ * Copyright 2009, 2010 Wolfson Microelectronics. PLC.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#ifndef __LINUX_SND_WM9090_H
+#define __LINUX_SND_WM9090_H
+
+struct wm9090_platform_data {
+	/* Line inputs 1 & 2 can optionally be differential */
+	unsigned int lin1_diff:1;
+	unsigned int lin2_diff:1;
+
+	/* AGC configuration.  This is intended to protect the speaker
+	 * against overdriving and will therefore depend on the
+	 * hardware setup with incorrect runtime configuration
+	 * potentially causing hardware damage.
+	 */
+	unsigned int agc_ena:1;
+	u16 agc[3];
+};
+
+#endif