[ALSA] ASoC AT91RM92000 audio DMA

This patch adds ASoC audio DMA support to the Atmel AT91RM9200 CPU.
Features:-
 o Playback/Capture supported.
 o 16 Bit data size.
Signed-off-by: Frank Mandarino <fmandarino@endrelia.com>
Signed-off-by: Liam Girdwood <liam.girdwood@wolfsonmicro.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Jaroslav Kysela <perex@suse.cz>

sound/soc/at91/at91rm9200-pcm.h

+/*
+ * at91rm9200-pcm.h - ALSA PCM interface for the Atmel AT91RM9200 chip
+ *
+ * Author:	Frank Mandarino <fmandarino@endrelia.com>
+ *		Endrelia Technologies Inc.
+ * Created:	Mar 3, 2006
+ *
+ * Based on pxa2xx-pcm.h by:
+ *
+ * Author:	Nicolas Pitre
+ * Created:	Nov 30, 2004
+ * Copyright:	MontaVista Software, Inc.
+ *
+ * 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.
+ */
+
+/*
+ * Registers and status bits that are required by the PCM driver.
+ */
+struct at91rm9200_ssc_regs {
+	void __iomem 	*cr;		/* SSC control */
+	void __iomem	*ier;		/* SSC interrupt enable */
+	void __iomem	*idr;		/* SSC interrupt disable */
+};
+
+struct at91rm9200_pdc_regs {
+	void __iomem	*xpr;		/* PDC recv/trans pointer */
+	void __iomem	*xcr;		/* PDC recv/trans counter */
+	void __iomem	*xnpr;		/* PDC next recv/trans pointer */
+	void __iomem	*xncr;		/* PDC next recv/trans counter */
+	void __iomem	*ptcr;		/* PDC transfer control */
+};
+
+struct at91rm9200_ssc_mask {
+	u32	ssc_enable;		/* SSC recv/trans enable */
+	u32	ssc_disable;		/* SSC recv/trans disable */
+	u32	ssc_endx;		/* SSC ENDTX or ENDRX */
+	u32	ssc_endbuf;		/* SSC TXBUFE or RXBUFF */
+	u32	pdc_enable;		/* PDC recv/trans enable */
+	u32	pdc_disable;		/* PDC recv/trans disable */
+};
+
+
+/*
+ * This structure, shared between the PCM driver and the interface,
+ * contains all information required by the PCM driver to perform the
+ * PDC DMA operation.  All fields except dma_intr_handler() are initialized
+ * by the interface.  The dms_intr_handler() pointer is set by the PCM
+ * driver and called by the interface SSC interrupt handler if it is
+ * non-NULL.
+ */
+typedef struct {
+	char *name;			/* stream identifier */
+	int pdc_xfer_size;		/* PDC counter increment in bytes */
+	struct at91rm9200_ssc_regs *ssc; /* SSC register addresses */
+	struct at91rm9200_pdc_regs *pdc; /* PDC receive/transmit registers */
+	struct at91rm9200_ssc_mask *mask;/* SSC & PDC status bits */
+	snd_pcm_substream_t *substream;
+	void (*dma_intr_handler)(u32, snd_pcm_substream_t *);
+} at91rm9200_pcm_dma_params_t;
+
+extern struct snd_soc_cpu_dai at91rm9200_i2s_dai[3];
+extern struct snd_soc_platform at91rm9200_soc_platform;
+
+
+/*
+ * SSC I/O helpers.
+ * E.g., at91_ssc_write(AT91_SSC(1) + AT91_SSC_CR, AT91_SSC_RXEN);
+ */
+#define AT91_SSC(x) (((x)==0) ? AT91_VA_BASE_SSC0 :\
+	 ((x)==1) ? AT91_VA_BASE_SSC1 : ((x)==2) ? AT91_VA_BASE_SSC2 : NULL)
+#define at91_ssc_read(a)	((unsigned long) __raw_readl(a))
+#define at91_ssc_write(a,v)	__raw_writel((v),(a))