[ARM] tegra: generic driver for i2s audio (initial implementation)

-- i2s settings are passed through the board file
-- supports playback (no recording yet)
-- works in DMA and PIO (non-DMA) modes (toggle through debugfs)
-- does NOT perform volume and audio-path control
-- exports /dev/audio<n>_{in, out}, where <n> is the i2s interface
-- assumes that i2s is used such that fifo1 is TX and fifo2 is RX

Signed-off-by: Iliyan Malchev <malchev@google.com>

arch/arm/mach-tegra/Makefile

@@ -10,6 +10,7 @@ obj-y                                   += delay.o
 obj-y                                   += powergate.o
 obj-y					+= suspend.o
 obj-y					+= fuse.o
+obj-y					+= tegra_i2s_audio.o
 obj-$(CONFIG_FIQ)                       += fiq.o
 obj-y                                   += usb_phy.o
 

arch/arm/mach-tegra/include/mach/audio.h

@@ -0,0 +1,46 @@
+/*
+ * arch/arm/mach-tegra/include/mach/audio.h
+ *
+ * Copyright (C) 2010 Google, Inc.
+ *
+ * Author:
+ *	Iliyan Malchev <malchev@google.com>
+ *
+ * This software is licensed under the terms of the GNU General Public
+ * License version 2, as published by the Free Software Foundation, and
+ * may be copied, distributed, and modified under those terms.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ */
+
+#ifndef __ARCH_ARM_MACH_TEGRA_AUDIO_H
+#define __ARCH_ARM_MACH_TEGRA_AUDIO_H
+
+#include <linux/kernel.h>
+#include <linux/types.h>
+#include <mach/i2s.h>
+
+#define FIFO1		0
+#define FIFO2		1
+
+/* FIXME: this is not enforced by the hardware. */
+#define I2S_FIFO_TX             FIFO1
+#define I2S_FIFO_RX             FIFO2
+
+struct tegra_audio_platform_data {
+	bool master;
+	bool dma_on;
+	unsigned long i2s_clk_rate;
+	const char *dap_clk;
+	const char *audio_sync_clk;
+
+	int mode; /* I2S, LJM, RJM, etc. */
+	int fifo_fmt;
+	int bit_size;
+};
+
+#endif /* __ARCH_ARM_MACH_TEGRA_AUDIO_H */