Driver for the Designware SPI core, it supports multipul interfaces like

PCI/APB etc.  User can use "dw_apb_ssi_db.pdf" from Synopsys as HW
datasheet.
Signed-off-by: Feng Tang <feng.tang@intel.com>
Cc: David Brownell <david-b@pacbell.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

drivers/spi/Kconfig

@@ -253,6 +253,12 @@ config SPI_XILINX
 # Add new SPI master controllers in alphabetical order above this line
 #
 
+config SPI_DESIGNWARE
+	bool "DesignWare SPI controller core support"
+	depends on SPI_MASTER
+	help
+	  general driver for SPI controller core from DesignWare
+
 #
 # There are lots of SPI device types, with sensors and memory
 # being probably the most widely used ones.

drivers/spi/Makefile

@@ -34,6 +34,7 @@ obj-$(CONFIG_SPI_TXX9)			+= spi_txx9.o
 obj-$(CONFIG_SPI_XILINX)		+= xilinx_spi.o
 obj-$(CONFIG_SPI_SH_SCI)		+= spi_sh_sci.o
 obj-$(CONFIG_SPI_STMP3XXX)		+= spi_stmp.o
+obj-$(CONFIG_SPI_DESIGNWARE)		+= dw_spi.o
 # 	... add above this line ...
 
 # SPI protocol drivers (device/link on bus)

include/linux/spi/dw_spi.h

+#ifndef DW_SPI_HEADER_H
+#define DW_SPI_HEADER_H
+#include <linux/io.h>
+
+/* Bit fields in CTRLR0 */
+#define SPI_DFS_OFFSET			0
+
+#define SPI_FRF_OFFSET			4
+#define SPI_FRF_SPI			0x0
+#define SPI_FRF_SSP			0x1
+#define SPI_FRF_MICROWIRE		0x2
+#define SPI_FRF_RESV			0x3
+
+#define SPI_MODE_OFFSET			6
+#define SPI_SCPH_OFFSET			6
+#define SPI_SCOL_OFFSET			7
+#define SPI_TMOD_OFFSET			8
+#define	SPI_TMOD_TR			0x0		/* xmit & recv */
+#define SPI_TMOD_TO			0x1		/* xmit only */
+#define SPI_TMOD_RO			0x2		/* recv only */
+#define SPI_TMOD_EPROMREAD		0x3		/* eeprom read mode */
+
+#define SPI_SLVOE_OFFSET		10
+#define SPI_SRL_OFFSET			11
+#define SPI_CFS_OFFSET			12
+
+/* Bit fields in SR, 7 bits */
+#define SR_MASK				0x7f		/* cover 7 bits */
+#define SR_BUSY				(1 << 0)
+#define SR_TF_NOT_FULL			(1 << 1)
+#define SR_TF_EMPT			(1 << 2)
+#define SR_RF_NOT_EMPT			(1 << 3)
+#define SR_RF_FULL			(1 << 4)
+#define SR_TX_ERR			(1 << 5)
+#define SR_DCOL				(1 << 6)
+
+/* Bit fields in ISR, IMR, RISR, 7 bits */
+#define SPI_INT_TXEI			(1 << 0)
+#define SPI_INT_TXOI			(1 << 1)
+#define SPI_INT_RXUI			(1 << 2)
+#define SPI_INT_RXOI			(1 << 3)
+#define SPI_INT_RXFI			(1 << 4)
+#define SPI_INT_MSTI			(1 << 5)
+
+/* TX RX interrupt level threshhold, max can be 256 */
+#define SPI_INT_THRESHOLD		32
+
+enum dw_ssi_type {
+	SSI_MOTO_SPI = 0,
+	SSI_TI_SSP,
+	SSI_NS_MICROWIRE,
+};
+
+struct dw_spi_reg {
+	u32	ctrl0;
+	u32	ctrl1;
+	u32	ssienr;
+	u32	mwcr;
+	u32	ser;
+	u32	baudr;
+	u32	txfltr;
+	u32	rxfltr;
+	u32	txflr;
+	u32	rxflr;
+	u32	sr;
+	u32	imr;
+	u32	isr;
+	u32	risr;
+	u32	txoicr;
+	u32	rxoicr;
+	u32	rxuicr;
+	u32	msticr;
+	u32	icr;
+	u32	dmacr;
+	u32	dmatdlr;
+	u32	dmardlr;
+	u32	idr;
+	u32	version;
+	u32	dr;		/* Currently oper as 32 bits,
+				though only low 16 bits matters */
+} __packed;
+
+struct dw_spi {
+	struct spi_master	*master;
+	struct spi_device	*cur_dev;
+	struct device		*parent_dev;
+	enum dw_ssi_type	type;
+
+	void __iomem		*regs;
+	unsigned long		paddr;
+	u32			iolen;
+	int			irq;
+	u32			max_freq;	/* max bus freq supported */
+
+	u16			bus_num;
+	u16			num_cs;		/* supported slave numbers */
+
+	/* Driver message queue */
+	struct workqueue_struct	*workqueue;
+	struct work_struct	pump_messages;
+	spinlock_t		lock;
+	struct list_head	queue;
+	int			busy;
+	int			run;
+
+	/* Message Transfer pump */
+	struct tasklet_struct	pump_transfers;
+
+	/* Current message transfer state info */
+	struct spi_message	*cur_msg;
+	struct spi_transfer	*cur_transfer;
+	struct chip_data	*cur_chip;
+	struct chip_data	*prev_chip;
+	size_t			len;
+	void			*tx;
+	void			*tx_end;
+	void			*rx;
+	void			*rx_end;
+	int			dma_mapped;
+	dma_addr_t		rx_dma;
+	dma_addr_t		tx_dma;
+	size_t			rx_map_len;
+	size_t			tx_map_len;
+	u8			n_bytes;	/* current is a 1/2 bytes op */
+	u8			max_bits_per_word;	/* maxim is 16b */
+	u32			dma_width;
+	int			cs_change;
+	int			(*write)(struct dw_spi *dws);
+	int			(*read)(struct dw_spi *dws);
+	irqreturn_t		(*transfer_handler)(struct dw_spi *dws);
+	void			(*cs_control)(u32 command);
+
+	/* Dma info */
+	int			dma_inited;
+	struct dma_chan		*txchan;
+	struct dma_chan		*rxchan;
+	int			txdma_done;
+	int			rxdma_done;
+	u64			tx_param;
+	u64			rx_param;
+	struct device		*dma_dev;
+	dma_addr_t		dma_addr;
+
+	/* Bus interface info */
+	void			*priv;
+#ifdef CONFIG_DEBUG_FS
+	struct dentry *debugfs;
+#endif
+};
+
+#define dw_readl(dw, name) \
+	__raw_readl(&(((struct dw_spi_reg *)dw->regs)->name))
+#define dw_writel(dw, name, val) \
+	__raw_writel((val), &(((struct dw_spi_reg *)dw->regs)->name))
+#define dw_readw(dw, name) \
+	__raw_readw(&(((struct dw_spi_reg *)dw->regs)->name))
+#define dw_writew(dw, name, val) \
+	__raw_writew((val), &(((struct dw_spi_reg *)dw->regs)->name))
+
+static inline void spi_enable_chip(struct dw_spi *dws, int enable)
+{
+	dw_writel(dws, ssienr, (enable ? 1 : 0));
+}
+
+static inline void spi_set_clk(struct dw_spi *dws, u16 div)
+{
+	dw_writel(dws, baudr, div);
+}
+
+static inline void spi_chip_sel(struct dw_spi *dws, u16 cs)
+{
+	if (cs > dws->num_cs)
+		return;
+	dw_writel(dws, ser, 1 << cs);
+}
+
+/* Disable IRQ bits */
+static inline void spi_mask_intr(struct dw_spi *dws, u32 mask)
+{
+	u32 new_mask;
+
+	new_mask = dw_readl(dws, imr) & ~mask;
+	dw_writel(dws, imr, new_mask);
+}
+
+/* Enable IRQ bits */
+static inline void spi_umask_intr(struct dw_spi *dws, u32 mask)
+{
+	u32 new_mask;
+
+	new_mask = dw_readl(dws, imr) | mask;
+	dw_writel(dws, imr, new_mask);
+}
+
+/*
+ * Each SPI slave device to work with dw_api controller should
+ * has such a structure claiming its working mode (PIO/DMA etc),
+ * which can be save in the "controller_data" member of the
+ * struct spi_device
+ */
+struct dw_spi_chip {
+	u8 poll_mode;	/* 0 for contoller polling mode */
+	u8 type;	/* SPI/SSP/Micrwire */
+	u8 enable_dma;
+	void (*cs_control)(u32 command);
+};
+
+extern int dw_spi_add_host(struct dw_spi *dws);
+extern void dw_spi_remove_host(struct dw_spi *dws);
+extern int dw_spi_suspend_host(struct dw_spi *dws);
+extern int dw_spi_resume_host(struct dw_spi *dws);
+#endif /* DW_SPI_HEADER_H */