[ARM] pxa: introduce plat-pxa for PXA common code and add DMA support

1. introduce folder of 'arch/arm/plat-pxa' for common code across different
   PXA processor families

2. initially moved DMA code into plat-pxa

3. common code in <mach/dma.h> moved into <plat/dma.h>, new processors
   should implement its own <mach/dma.h>, provide the following required
   definitions and '#include <plat/dma.h>' in the end:

   - DMAC_REGS_VIRT for mapped virtual address of the DMA registers'
     physical I/O memory

Signed-off-by: Eric Miao <eric.miao@marvell.com>

1 files changed, 85 insertions, 0 deletions

diff --git a/arch/arm/plat-pxa/include/plat/dma.h b/arch/arm/plat-pxa/include/plat/dma.h
new file mode 100644
index 00000000000..a7b91dc0685
--- /dev/null
+++ b/arch/arm/plat-pxa/include/plat/dma.h
@@ -0,0 +1,85 @@
+#ifndef __PLAT_DMA_H
+#define __PLAT_DMA_H
+
+#define DMAC_REG(x)	(*((volatile u32 *)(DMAC_REGS_VIRT + (x))))
+
+#define DCSR(n)		DMAC_REG((n) << 2)
+#define DALGN		DMAC_REG(0x00a0)  /* DMA Alignment Register */
+#define DINT		DMAC_REG(0x00f0)  /* DMA Interrupt Register */
+#define DDADR(n)	DMAC_REG(0x0200 + ((n) << 4))
+#define DSADR(n)	DMAC_REG(0x0204 + ((n) << 4))
+#define DTADR(n)	DMAC_REG(0x0208 + ((n) << 4))
+#define DCMD(n)		DMAC_REG(0x020c + ((n) << 4))
+#define DRCMR(n)	DMAC_REG((((n) < 64) ? 0x0100 : 0x1100) + \
+				 (((n) & 0x3f) << 2))
+
+#define DCSR_RUN	(1 << 31)	/* Run Bit (read / write) */
+#define DCSR_NODESC	(1 << 30)	/* No-Descriptor Fetch (read / write) */
+#define DCSR_STOPIRQEN	(1 << 29)	/* Stop Interrupt Enable (read / write) */
+#define DCSR_REQPEND	(1 << 8)	/* Request Pending (read-only) */
+#define DCSR_STOPSTATE	(1 << 3)	/* Stop State (read-only) */
+#define DCSR_ENDINTR	(1 << 2)	/* End Interrupt (read / write) */
+#define DCSR_STARTINTR	(1 << 1)	/* Start Interrupt (read / write) */
+#define DCSR_BUSERR	(1 << 0)	/* Bus Error Interrupt (read / write) */
+
+#define DCSR_EORIRQEN	(1 << 28)       /* End of Receive Interrupt Enable (R/W) */
+#define DCSR_EORJMPEN	(1 << 27)       /* Jump to next descriptor on EOR */
+#define DCSR_EORSTOPEN	(1 << 26)       /* STOP on an EOR */
+#define DCSR_SETCMPST	(1 << 25)       /* Set Descriptor Compare Status */
+#define DCSR_CLRCMPST	(1 << 24)       /* Clear Descriptor Compare Status */
+#define DCSR_CMPST	(1 << 10)       /* The Descriptor Compare Status */
+#define DCSR_EORINTR	(1 << 9)        /* The end of Receive */
+
+#define DRCMR_MAPVLD	(1 << 7)	/* Map Valid (read / write) */
+#define DRCMR_CHLNUM	0x1f		/* mask for Channel Number (read / write) */
+
+#define DDADR_DESCADDR	0xfffffff0	/* Address of next descriptor (mask) */
+#define DDADR_STOP	(1 << 0)	/* Stop (read / write) */
+
+#define DCMD_INCSRCADDR	(1 << 31)	/* Source Address Increment Setting. */
+#define DCMD_INCTRGADDR	(1 << 30)	/* Target Address Increment Setting. */
+#define DCMD_FLOWSRC	(1 << 29)	/* Flow Control by the source. */
+#define DCMD_FLOWTRG	(1 << 28)	/* Flow Control by the target. */
+#define DCMD_STARTIRQEN	(1 << 22)	/* Start Interrupt Enable */
+#define DCMD_ENDIRQEN	(1 << 21)	/* End Interrupt Enable */
+#define DCMD_ENDIAN	(1 << 18)	/* Device Endian-ness. */
+#define DCMD_BURST8	(1 << 16)	/* 8 byte burst */
+#define DCMD_BURST16	(2 << 16)	/* 16 byte burst */
+#define DCMD_BURST32	(3 << 16)	/* 32 byte burst */
+#define DCMD_WIDTH1	(1 << 14)	/* 1 byte width */
+#define DCMD_WIDTH2	(2 << 14)	/* 2 byte width (HalfWord) */
+#define DCMD_WIDTH4	(3 << 14)	/* 4 byte width (Word) */
+#define DCMD_LENGTH	0x01fff		/* length mask (max = 8K - 1) */
+
+/*
+ * Descriptor structure for PXA's DMA engine
+ * Note: this structure must always be aligned to a 16-byte boundary.
+ */
+
+typedef struct pxa_dma_desc {
+	volatile u32 ddadr;	/* Points to the next descriptor + flags */
+	volatile u32 dsadr;	/* DSADR value for the current transfer */
+	volatile u32 dtadr;	/* DTADR value for the current transfer */
+	volatile u32 dcmd;	/* DCMD value for the current transfer */
+} pxa_dma_desc;
+
+typedef enum {
+	DMA_PRIO_HIGH = 0,
+	DMA_PRIO_MEDIUM = 1,
+	DMA_PRIO_LOW = 2
+} pxa_dma_prio;
+
+/*
+ * DMA registration
+ */
+
+int __init pxa_init_dma(int irq, int num_ch);
+
+int pxa_request_dma (char *name,
+			 pxa_dma_prio prio,
+			 void (*irq_handler)(int, void *),
+			 void *data);
+
+void pxa_free_dma (int dma_ch);
+
+#endif /* __PLAT_DMA_H */