drivers/spi/spi-sirf.c

/*
 * SPI bus driver for CSR SiRFprimaII
 *
 * Copyright (c) 2011 Cambridge Silicon Radio Limited, a CSR plc group company.
 *
 * Licensed under GPLv2 or later.
 */

#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/slab.h>
#include <linux/clk.h>
#include <linux/completion.h>
#include <linux/interrupt.h>
#include <linux/io.h>
#include <linux/of.h>
#include <linux/bitops.h>
#include <linux/err.h>
#include <linux/platform_device.h>
#include <linux/of_gpio.h>
#include <linux/spi/spi.h>
#include <linux/spi/spi_bitbang.h>
#include <linux/dmaengine.h>
#include <linux/dma-direction.h>
#include <linux/dma-mapping.h>
#include <linux/reset.h>

#define DRIVER_NAME "sirfsoc_spi"
/* SPI CTRL register defines */
#define SIRFSOC_SPI_SLV_MODE		BIT(16)
#define SIRFSOC_SPI_CMD_MODE		BIT(17)
#define SIRFSOC_SPI_CS_IO_OUT		BIT(18)
#define SIRFSOC_SPI_CS_IO_MODE		BIT(19)
#define SIRFSOC_SPI_CLK_IDLE_STAT	BIT(20)
#define SIRFSOC_SPI_CS_IDLE_STAT	BIT(21)
#define SIRFSOC_SPI_TRAN_MSB		BIT(22)
#define SIRFSOC_SPI_DRV_POS_EDGE	BIT(23)
#define SIRFSOC_SPI_CS_HOLD_TIME	BIT(24)
#define SIRFSOC_SPI_CLK_SAMPLE_MODE	BIT(25)
#define SIRFSOC_SPI_TRAN_DAT_FORMAT_8	(0 << 26)
#define SIRFSOC_SPI_TRAN_DAT_FORMAT_12	(1 << 26)
#define SIRFSOC_SPI_TRAN_DAT_FORMAT_16	(2 << 26)
#define SIRFSOC_SPI_TRAN_DAT_FORMAT_32	(3 << 26)
#define SIRFSOC_SPI_CMD_BYTE_NUM(x)	((x & 3) << 28)
#define SIRFSOC_SPI_ENA_AUTO_CLR	BIT(30)
#define SIRFSOC_SPI_MUL_DAT_MODE	BIT(31)

/* Interrupt Enable */
#define SIRFSOC_SPI_RX_DONE_INT_EN	BIT(0)
#define SIRFSOC_SPI_TX_DONE_INT_EN	BIT(1)
#define SIRFSOC_SPI_RX_OFLOW_INT_EN	BIT(2)
#define SIRFSOC_SPI_TX_UFLOW_INT_EN	BIT(3)
#define SIRFSOC_SPI_RX_IO_DMA_INT_EN	BIT(4)
#define SIRFSOC_SPI_TX_IO_DMA_INT_EN	BIT(5)
#define SIRFSOC_SPI_RXFIFO_FULL_INT_EN	BIT(6)
#define SIRFSOC_SPI_TXFIFO_EMPTY_INT_EN	BIT(7)
#define SIRFSOC_SPI_RXFIFO_THD_INT_EN	BIT(8)
#define SIRFSOC_SPI_TXFIFO_THD_INT_EN	BIT(9)
#define SIRFSOC_SPI_FRM_END_INT_EN	BIT(10)

/* Interrupt status */
#define SIRFSOC_SPI_RX_DONE		BIT(0)
#define SIRFSOC_SPI_TX_DONE		BIT(1)
#define SIRFSOC_SPI_RX_OFLOW		BIT(2)
#define SIRFSOC_SPI_TX_UFLOW		BIT(3)
#define SIRFSOC_SPI_RX_IO_DMA		BIT(4)
#define SIRFSOC_SPI_RX_FIFO_FULL	BIT(6)
#define SIRFSOC_SPI_TXFIFO_EMPTY	BIT(7)
#define SIRFSOC_SPI_RXFIFO_THD_REACH	BIT(8)
#define SIRFSOC_SPI_TXFIFO_THD_REACH	BIT(9)
#define SIRFSOC_SPI_FRM_END		BIT(10)

/* TX RX enable */
#define SIRFSOC_SPI_RX_EN		BIT(0)
#define SIRFSOC_SPI_TX_EN		BIT(1)
#define SIRFSOC_SPI_CMD_TX_EN		BIT(2)

#define SIRFSOC_SPI_IO_MODE_SEL		BIT(0)
#define SIRFSOC_SPI_RX_DMA_FLUSH	BIT(2)

/* FIFO OPs */
#define SIRFSOC_SPI_FIFO_RESET		BIT(0)
#define SIRFSOC_SPI_FIFO_START		BIT(1)

/* FIFO CTRL */
#define SIRFSOC_SPI_FIFO_WIDTH_BYTE	(0 << 0)
#define SIRFSOC_SPI_FIFO_WIDTH_WORD	(1 << 0)
#define SIRFSOC_SPI_FIFO_WIDTH_DWORD	(2 << 0)
/* USP related */
#define SIRFSOC_USP_SYNC_MODE		BIT(0)
#define SIRFSOC_USP_SLV_MODE		BIT(1)
#define SIRFSOC_USP_LSB			BIT(4)
#define SIRFSOC_USP_EN			BIT(5)
#define SIRFSOC_USP_RXD_FALLING_EDGE	BIT(6)
#define SIRFSOC_USP_TXD_FALLING_EDGE	BIT(7)
#define SIRFSOC_USP_CS_HIGH_VALID	BIT(9)
#define SIRFSOC_USP_SCLK_IDLE_STAT	BIT(11)
#define SIRFSOC_USP_TFS_IO_MODE		BIT(14)
#define SIRFSOC_USP_TFS_IO_INPUT	BIT(19)

#define SIRFSOC_USP_RXD_DELAY_LEN_MASK	0xFF
#define SIRFSOC_USP_TXD_DELAY_LEN_MASK	0xFF
#define SIRFSOC_USP_RXD_DELAY_OFFSET	0
#define SIRFSOC_USP_TXD_DELAY_OFFSET	8
#define SIRFSOC_USP_RXD_DELAY_LEN	1
#define SIRFSOC_USP_TXD_DELAY_LEN	1
#define SIRFSOC_USP_CLK_DIVISOR_OFFSET	21
#define SIRFSOC_USP_CLK_DIVISOR_MASK	0x3FF
#define SIRFSOC_USP_CLK_10_11_MASK	0x3
#define SIRFSOC_USP_CLK_10_11_OFFSET	30
#define SIRFSOC_USP_CLK_12_15_MASK	0xF
#define SIRFSOC_USP_CLK_12_15_OFFSET	24

#define SIRFSOC_USP_TX_DATA_OFFSET	0
#define SIRFSOC_USP_TX_SYNC_OFFSET	8
#define SIRFSOC_USP_TX_FRAME_OFFSET	16
#define SIRFSOC_USP_TX_SHIFTER_OFFSET	24

#define SIRFSOC_USP_TX_DATA_MASK	0xFF
#define SIRFSOC_USP_TX_SYNC_MASK	0xFF
#define SIRFSOC_USP_TX_FRAME_MASK	0xFF
#define SIRFSOC_USP_TX_SHIFTER_MASK	0x1F

#define SIRFSOC_USP_RX_DATA_OFFSET	0
#define SIRFSOC_USP_RX_FRAME_OFFSET	8
#define SIRFSOC_USP_RX_SHIFTER_OFFSET	16

#define SIRFSOC_USP_RX_DATA_MASK	0xFF
#define SIRFSOC_USP_RX_FRAME_MASK	0xFF
#define SIRFSOC_USP_RX_SHIFTER_MASK	0x1F
#define SIRFSOC_USP_CS_HIGH_VALUE	BIT(1)

#define SIRFSOC_SPI_FIFO_SC_OFFSET	0
#define SIRFSOC_SPI_FIFO_LC_OFFSET	10
#define SIRFSOC_SPI_FIFO_HC_OFFSET	20

#define SIRFSOC_SPI_FIFO_FULL_MASK(s)	(1 << ((s)->fifo_full_offset))
#define SIRFSOC_SPI_FIFO_EMPTY_MASK(s)	(1 << ((s)->fifo_full_offset + 1))
#define SIRFSOC_SPI_FIFO_THD_MASK(s)	((s)->fifo_size - 1)
#define SIRFSOC_SPI_FIFO_THD_OFFSET	2
#define SIRFSOC_SPI_FIFO_LEVEL_CHK_MASK(s, val)	\
	((val) & (s)->fifo_level_chk_mask)

enum sirf_spi_type {
	SIRF_REAL_SPI,
	SIRF_USP_SPI_P2,
	SIRF_USP_SPI_A7,
};

/*
 * only if the rx/tx buffer and transfer size are 4-bytes aligned, we use dma
 * due to the limitation of dma controller
 */

#define ALIGNED(x) (!((u32)x & 0x3))
#define IS_DMA_VALID(x) (x && ALIGNED(x->tx_buf) && ALIGNED(x->rx_buf) && \
	ALIGNED(x->len) && (x->len < 2 * PAGE_SIZE))

#define SIRFSOC_MAX_CMD_BYTES	4
#define SIRFSOC_SPI_DEFAULT_FRQ 1000000

struct sirf_spi_register {
	/*SPI and USP-SPI common*/
	u32 tx_rx_en;
	u32 int_en;
	u32 int_st;
	u32 tx_dma_io_ctrl;
	u32 tx_dma_io_len;
	u32 txfifo_ctrl;
	u32 txfifo_level_chk;
	u32 txfifo_op;
	u32 txfifo_st;
	u32 txfifo_data;
	u32 rx_dma_io_ctrl;
	u32 rx_dma_io_len;
	u32 rxfifo_ctrl;
	u32 rxfifo_level_chk;
	u32 rxfifo_op;
	u32 rxfifo_st;
	u32 rxfifo_data;
	/*SPI self*/
	u32 spi_ctrl;
	u32 spi_cmd;
	u32 spi_dummy_delay_ctrl;
	/*USP-SPI self*/
	u32 usp_mode1;
	u32 usp_mode2;
	u32 usp_tx_frame_ctrl;
	u32 usp_rx_frame_ctrl;
	u32 usp_pin_io_data;
	u32 usp_risc_dsp_mode;
	u32 usp_async_param_reg;
	u32 usp_irda_x_mode_div;
	u32 usp_sm_cfg;
	u32 usp_int_en_clr;
};

static const struct sirf_spi_register real_spi_register = {
	.tx_rx_en		= 0x8,
	.int_en		= 0xc,
	.int_st		= 0x10,
	.tx_dma_io_ctrl	= 0x100,
	.tx_dma_io_len	= 0x104,
	.txfifo_ctrl	= 0x108,
	.txfifo_level_chk	= 0x10c,
	.txfifo_op		= 0x110,
	.txfifo_st		= 0x114,
	.txfifo_data	= 0x118,
	.rx_dma_io_ctrl	= 0x120,
	.rx_dma_io_len	= 0x124,
	.rxfifo_ctrl	= 0x128,
	.rxfifo_level_chk	= 0x12c,
	.rxfifo_op		= 0x130,
	.rxfifo_st		= 0x134,
	.rxfifo_data	= 0x138,
	.spi_ctrl		= 0x0,
	.spi_cmd		= 0x4,
	.spi_dummy_delay_ctrl	= 0x144,
};

static const struct sirf_spi_register usp_spi_register = {
	.tx_rx_en		= 0x10,
	.int_en		= 0x14,
	.int_st		= 0x18,
	.tx_dma_io_ctrl	= 0x100,
	.tx_dma_io_len	= 0x104,
	.txfifo_ctrl	= 0x108,
	.txfifo_level_chk	= 0x10c,
	.txfifo_op		= 0x110,
	.txfifo_st		= 0x114,
	.txfifo_data	= 0x118,
	.rx_dma_io_ctrl	= 0x120,
	.rx_dma_io_len	= 0x124,
	.rxfifo_ctrl	= 0x128,
	.rxfifo_level_chk	= 0x12c,
	.rxfifo_op		= 0x130,
	.rxfifo_st		= 0x134,
	.rxfifo_data	= 0x138,
	.usp_mode1		= 0x0,
	.usp_mode2		= 0x4,
	.usp_tx_frame_ctrl	= 0x8,
	.usp_rx_frame_ctrl	= 0xc,
	.usp_pin_io_data	= 0x1c,
	.usp_risc_dsp_mode	= 0x20,
	.usp_async_param_reg	= 0x24,
	.usp_irda_x_mode_div	= 0x28,
	.usp_sm_cfg		= 0x2c,
	.usp_int_en_clr		= 0x140,
};

struct sirfsoc_spi {
	struct spi_bitbang bitbang;
	struct completion rx_done;
	struct completion tx_done;

	void __iomem *base;
	u32 ctrl_freq;  /* SPI controller clock speed */
	struct clk *clk;

	/* rx & tx bufs from the spi_transfer */
	const void *tx;
	void *rx;

	/* place received word into rx buffer */
	void (*rx_word) (struct sirfsoc_spi *);
	/* get word from tx buffer for sending */
	void (*tx_word) (struct sirfsoc_spi *);

	/* number of words left to be tranmitted/received */
	unsigned int left_tx_word;
	unsigned int left_rx_word;

	/* rx & tx DMA channels */
	struct dma_chan *rx_chan;
	struct dma_chan *tx_chan;
	dma_addr_t src_start;
	dma_addr_t dst_start;
	int word_width; /* in bytes */

	/*
	 * if tx size is not more than 4 and rx size is NULL, use
	 * command model
	 */
	bool	tx_by_cmd;
	bool	hw_cs;
	enum sirf_spi_type type;
	const struct sirf_spi_register *regs;
	unsigned int fifo_size;
	/* fifo empty offset is (fifo full offset + 1)*/
	unsigned int fifo_full_offset;
	/* fifo_level_chk_mask is (fifo_size/4 - 1) */
	unsigned int fifo_level_chk_mask;
	unsigned int dat_max_frm_len;
};

struct sirf_spi_comp_data {
	const struct sirf_spi_register *regs;
	enum sirf_spi_type type;
	unsigned int dat_max_frm_len;
	unsigned int fifo_size;
	void (*hwinit)(struct sirfsoc_spi *sspi);
};

static void sirfsoc_usp_hwinit(struct sirfsoc_spi *sspi)
{
	/* reset USP and let USP can operate */
	writel(readl(sspi->base + sspi->regs->usp_mode1) &
		~SIRFSOC_USP_EN, sspi->base + sspi->regs->usp_mode1);
	writel(readl(sspi->base + sspi->regs->usp_mode1) |
		SIRFSOC_USP_EN, sspi->base + sspi->regs->usp_mode1);
}

static void spi_sirfsoc_rx_word_u8(struct sirfsoc_spi *sspi)
{
	u32 data;
	u8 *rx = sspi->rx;

	data = readl(sspi->base + sspi->regs->rxfifo_data);

	if (rx) {
		*rx++ = (u8) data;
		sspi->rx = rx;
	}

	sspi->left_rx_word--;
}

static void spi_sirfsoc_tx_word_u8(struct sirfsoc_spi *sspi)
{
	u32 data = 0;
	const u8 *tx = sspi->tx;

	if (tx) {
		data = *tx++;
		sspi->tx = tx;
	}
	writel(data, sspi->base + sspi->regs->txfifo_data);
	sspi->left_tx_word--;
}

static void spi_sirfsoc_rx_word_u16(struct sirfsoc_spi *sspi)
{
	u32 data;
	u16 *rx = sspi->rx;

	data = readl(sspi->base + sspi->regs->rxfifo_data);

	if (rx) {
		*rx++ = (u16) data;
		sspi->rx = rx;
	}

	sspi->left_rx_word--;
}

static void spi_sirfsoc_tx_word_u16(struct sirfsoc_spi *sspi)
{
	u32 data = 0;
	const u16 *tx = sspi->tx;

	if (tx) {
		data = *tx++;
		sspi->tx = tx;
	}

	writel(data, sspi->base + sspi->regs->txfifo_data);
	sspi->left_tx_word--;
}

static void spi_sirfsoc_rx_word_u32(struct sirfsoc_spi *sspi)
{
	u32 data;
	u32 *rx = sspi->rx;

	data = readl(sspi->base + sspi->regs->rxfifo_data);

	if (rx) {
		*rx++ = (u32) data;
		sspi->rx = rx;
	}

	sspi->left_rx_word--;

}

static void spi_sirfsoc_tx_word_u32(struct sirfsoc_spi *sspi)
{
	u32 data = 0;
	const u32 *tx = sspi->tx;

	if (tx) {
		data = *tx++;
		sspi->tx = tx;
	}

	writel(data, sspi->base + sspi->regs->txfifo_data);
	sspi->left_tx_word--;
}

static irqreturn_t spi_sirfsoc_irq(int irq, void *dev_id)
{
	struct sirfsoc_spi *sspi = dev_id;
	u32 spi_stat;

	spi_stat = readl(sspi->base + sspi->regs->int_st);
	if (sspi->tx_by_cmd && sspi->type == SIRF_REAL_SPI
		&& (spi_stat & SIRFSOC_SPI_FRM_END)) {
		complete(&sspi->tx_done);
		writel(0x0, sspi->base + sspi->regs->int_en);
		writel(readl(sspi->base + sspi->regs->int_st),
				sspi->base + sspi->regs->int_st);
		return IRQ_HANDLED;
	}
	/* Error Conditions */
	if (spi_stat & SIRFSOC_SPI_RX_OFLOW ||
			spi_stat & SIRFSOC_SPI_TX_UFLOW) {
		complete(&sspi->tx_done);
		complete(&sspi->rx_done);
		switch (sspi->type) {
		case SIRF_REAL_SPI:
		case SIRF_USP_SPI_P2:
			writel(0x0, sspi->base + sspi->regs->int_en);
			break;
		case SIRF_USP_SPI_A7:
			writel(~0UL, sspi->base + sspi->regs->usp_int_en_clr);
			break;
		}
		writel(readl(sspi->base + sspi->regs->int_st),
				sspi->base + sspi->regs->int_st);
		return IRQ_HANDLED;
	}
	if (spi_stat & SIRFSOC_SPI_TXFIFO_EMPTY)
		complete(&sspi->tx_done);
	while (!(readl(sspi->base + sspi->regs->int_st) &
		SIRFSOC_SPI_RX_IO_DMA))
		cpu_relax();
	complete(&sspi->rx_done);
	switch (sspi->type) {
	case SIRF_REAL_SPI:
	case SIRF_USP_SPI_P2:
		writel(0x0, sspi->base + sspi->regs->int_en);
		break;
	case SIRF_USP_SPI_A7:
		writel(~0UL, sspi->base + sspi->regs->usp_int_en_clr);
		break;
	}
	writel(readl(sspi->base + sspi->regs->int_st),
			sspi->base + sspi->regs->int_st);

	return IRQ_HANDLED;
}

static void spi_sirfsoc_dma_fini_callback(void *data)
{
	struct completion *dma_complete = data;

	complete(dma_complete);
}

static void spi_sirfsoc_cmd_transfer(struct spi_device *spi,
	struct spi_transfer *t)
{
	struct sirfsoc_spi *sspi;
	int timeout = t->len * 10;
	u32 cmd;

	sspi = spi_master_get_devdata(spi->master);
	writel(SIRFSOC_SPI_FIFO_RESET, sspi->base + sspi->regs->txfifo_op);
	writel(SIRFSOC_SPI_FIFO_START, sspi->base + sspi->regs->txfifo_op);
	memcpy(&cmd, sspi->tx, t->len);
	if (sspi->word_width == 1 && !(spi->mode & SPI_LSB_FIRST))
		cmd = cpu_to_be32(cmd) >>
			((SIRFSOC_MAX_CMD_BYTES - t->len) * 8);
	if (sspi->word_width == 2 && t->len == 4 &&
			(!(spi->mode & SPI_LSB_FIRST)))
		cmd = ((cmd & 0xffff) << 16) | (cmd >> 16);
	writel(cmd, sspi->base + sspi->regs->spi_cmd);
	writel(SIRFSOC_SPI_FRM_END_INT_EN,
		sspi->base + sspi->regs->int_en);
	writel(SIRFSOC_SPI_CMD_TX_EN,
		sspi->base + sspi->regs->tx_rx_en);
	if (wait_for_completion_timeout(&sspi->tx_done, timeout) == 0) {
		dev_err(&spi->dev, "cmd transfer timeout\n");
		return;
	}
	sspi->left_rx_word -= t->len;
}

static void spi_sirfsoc_dma_transfer(struct spi_device *spi,
	struct spi_transfer *t)
{
	struct sirfsoc_spi *sspi;
	struct dma_async_tx_descriptor *rx_desc, *tx_desc;
	int timeout = t->len * 10;

	sspi = spi_master_get_devdata(spi->master);
	writel(SIRFSOC_SPI_FIFO_RESET, sspi->base + sspi->regs->rxfifo_op);
	writel(SIRFSOC_SPI_FIFO_RESET, sspi->base + sspi->regs->txfifo_op);
	switch (sspi->type) {
	case SIRF_REAL_SPI:
		writel(SIRFSOC_SPI_FIFO_START,
			sspi->base + sspi->regs->rxfifo_op);
		writel(SIRFSOC_SPI_FIFO_START,
			sspi->base + sspi->regs->txfifo_op);
		writel(0, sspi->base + sspi->regs->int_en);
		break;
	case SIRF_USP_SPI_P2:
		writel(0x0, sspi->base + sspi->regs->rxfifo_op);
		writel(0x0, sspi->base + sspi->regs->txfifo_op);
		writel(0, sspi->base + sspi->regs->int_en);
		break;
	case SIRF_USP_SPI_A7:
		writel(0x0, sspi->base + sspi->regs->rxfifo_op);
		writel(0x0, sspi->base + sspi->regs->txfifo_op);
		writel(~0UL, sspi->base + sspi->regs->usp_int_en_clr);
		break;
	}
	writel(readl(sspi->base + sspi->regs->int_st),
		sspi->base + sspi->regs->int_st);
	if (sspi->left_tx_word < sspi->dat_max_frm_len) {
		switch (sspi->type) {
		case SIRF_REAL_SPI:
			writel(readl(sspi->base + sspi->regs->spi_ctrl) |
				SIRFSOC_SPI_ENA_AUTO_CLR |
				SIRFSOC_SPI_MUL_DAT_MODE,
				sspi->base + sspi->regs->spi_ctrl);
			writel(sspi->left_tx_word - 1,
				sspi->base + sspi->regs->tx_dma_io_len);
			writel(sspi->left_tx_word - 1,
				sspi->base + sspi->regs->rx_dma_io_len);
			break;
		case SIRF_USP_SPI_P2:
		case SIRF_USP_SPI_A7:
			/*USP simulate SPI, tx/rx_dma_io_len indicates bytes*/
			writel(sspi->left_tx_word * sspi->word_width,
				sspi->base + sspi->regs->tx_dma_io_len);
			writel(sspi->left_tx_word * sspi->word_width,
				sspi->base + sspi->regs->rx_dma_io_len);
			break;
		}
	} else {
		if (sspi->type == SIRF_REAL_SPI)
			writel(readl(sspi->base + sspi->regs->spi_ctrl),
				sspi->base + sspi->regs->spi_ctrl);
		writel(0, sspi->base + sspi->regs->tx_dma_io_len);
		writel(0, sspi->base + sspi->regs->rx_dma_io_len);
	}
	sspi->dst_start = dma_map_single(&spi->dev, sspi->rx, t->len,
					(t->tx_buf != t->rx_buf) ?
					DMA_FROM_DEVICE : DMA_BIDIRECTIONAL);
	rx_desc = dmaengine_prep_slave_single(sspi->rx_chan,
		sspi->dst_start, t->len, DMA_DEV_TO_MEM,
		DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
	rx_desc->callback = spi_sirfsoc_dma_fini_callback;
	rx_desc->callback_param = &sspi->rx_done;

	sspi->src_start = dma_map_single(&spi->dev, (void *)sspi->tx, t->len,
					(t->tx_buf != t->rx_buf) ?
					DMA_TO_DEVICE : DMA_BIDIRECTIONAL);
	tx_desc = dmaengine_prep_slave_single(sspi->tx_chan,
		sspi->src_start, t->len, DMA_MEM_TO_DEV,
		DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
	tx_desc->callback = spi_sirfsoc_dma_fini_callback;
	tx_desc->callback_param = &sspi->tx_done;

	dmaengine_submit(tx_desc);
	dmaengine_submit(rx_desc);
	dma_async_issue_pending(sspi->tx_chan);
	dma_async_issue_pending(sspi->rx_chan);
	writel(SIRFSOC_SPI_RX_EN | SIRFSOC_SPI_TX_EN,
			sspi->base + sspi->regs->tx_rx_en);
	if (sspi->type == SIRF_USP_SPI_P2 ||
		sspi->type == SIRF_USP_SPI_A7) {
		writel(SIRFSOC_SPI_FIFO_START,
			sspi->base + sspi->regs->rxfifo_op);
		writel(SIRFSOC_SPI_FIFO_START,
			sspi->base + sspi->regs->txfifo_op);
	}
	if (wait_for_completion_timeout(&sspi->rx_done, timeout) == 0) {
		dev_err(&spi->dev, "transfer timeout\n");
		dmaengine_terminate_all(sspi->rx_chan);
	} else
		sspi->left_rx_word = 0;
	/*
	 * we only wait tx-done event if transferring by DMA. for PIO,
	 * we get rx data by writing tx data, so if rx is done, tx has
	 * done earlier
	 */
	if (wait_for_completion_timeout(&sspi->tx_done, timeout) == 0) {
		dev_err(&spi->dev, "transfer timeout\n");
		if (sspi->type == SIRF_USP_SPI_P2 ||
			sspi->type == SIRF_USP_SPI_A7)
			writel(0, sspi->base + sspi->regs->tx_rx_en);
		dmaengine_terminate_all(sspi->tx_chan);
	}
	dma_unmap_single(&spi->dev, sspi->src_start, t->len, DMA_TO_DEVICE);
	dma_unmap_single(&spi->dev, sspi->dst_start, t->len, DMA_FROM_DEVICE);
	/* TX, RX FIFO stop */
	writel(0, sspi->base + sspi->regs->rxfifo_op);
	writel(0, sspi->base + sspi->regs->txfifo_op);
	if (sspi->left_tx_word >= sspi->dat_max_frm_len)
		writel(0, sspi->base + sspi->regs->tx_rx_en);
	if (sspi->type == SIRF_USP_SPI_P2 ||
		sspi->type == SIRF_USP_SPI_A7)
		writel(0, sspi->base + sspi->regs->tx_rx_en);
}

static void spi_sirfsoc_pio_transfer(struct spi_device *spi,
		struct spi_transfer *t)
{
	struct sirfsoc_spi *sspi;
	int timeout = t->len * 10;
	unsigned int data_units;

	sspi = spi_master_get_devdata(spi->master);
	do {
		writel(SIRFSOC_SPI_FIFO_RESET,
			sspi->base + sspi->regs->rxfifo_op);
		writel(SIRFSOC_SPI_FIFO_RESET,
			sspi->base + sspi->regs->txfifo_op);
		switch (sspi->type) {
		case SIRF_USP_SPI_P2:
			writel(0x0, sspi->base + sspi->regs->rxfifo_op);
			writel(0x0, sspi->base + sspi->regs->txfifo_op);
			writel(0, sspi->base + sspi->regs->int_en);
			writel(readl(sspi->base + sspi->regs->int_st),
				sspi->base + sspi->regs->int_st);
			writel(min((sspi->left_tx_word * sspi->word_width),
				sspi->fifo_size),
				sspi->base + sspi->regs->tx_dma_io_len);
			writel(min((sspi->left_rx_word * sspi->word_width),
				sspi->fifo_size),
				sspi->base + sspi->regs->rx_dma_io_len);
			break;
		case SIRF_USP_SPI_A7:
			writel(0x0, sspi->base + sspi->regs->rxfifo_op);
			writel(0x0, sspi->base + sspi->regs->txfifo_op);
			writel(~0UL, sspi->base + sspi->regs->usp_int_en_clr);
			writel(readl(sspi->base + sspi->regs->int_st),
				sspi->base + sspi->regs->int_st);
			writel(min((sspi->left_tx_word * sspi->word_width),
				sspi->fifo_size),
				sspi->base + sspi->regs->tx_dma_io_len);
			writel(min((sspi->left_rx_word * sspi->word_width),
				sspi->fifo_size),
				sspi->base + sspi->regs->rx_dma_io_len);
			break;
		case SIRF_REAL_SPI:
			writel(SIRFSOC_SPI_FIFO_START,
				sspi->base + sspi->regs->rxfifo_op);
			writel(SIRFSOC_SPI_FIFO_START,
				sspi->base + sspi->regs->txfifo_op);
			writel(0, sspi->base + sspi->regs->int_en);
			writel(readl(sspi->base + sspi->regs->int_st),
				sspi->base + sspi->regs->int_st);
			writel(readl(sspi->base + sspi->regs->spi_ctrl) |
				SIRFSOC_SPI_MUL_DAT_MODE |
				SIRFSOC_SPI_ENA_AUTO_CLR,
				sspi->base + sspi->regs->spi_ctrl);
			data_units = sspi->fifo_size / sspi->word_width;
			writel(min(sspi->left_tx_word, data_units) - 1,
				sspi->base + sspi->regs->tx_dma_io_len);
			writel(min(sspi->left_rx_word, data_units) - 1,
				sspi->base + sspi->regs->rx_dma_io_len);
			break;
		}
		while (!((readl(sspi->base + sspi->regs->txfifo_st)
			& SIRFSOC_SPI_FIFO_FULL_MASK(sspi))) &&
			sspi->left_tx_word)
			sspi->tx_word(sspi);
		writel(SIRFSOC_SPI_TXFIFO_EMPTY_INT_EN |
			SIRFSOC_SPI_TX_UFLOW_INT_EN |
			SIRFSOC_SPI_RX_OFLOW_INT_EN |
			SIRFSOC_SPI_RX_IO_DMA_INT_EN,
			sspi->base + sspi->regs->int_en);
		writel(SIRFSOC_SPI_RX_EN | SIRFSOC_SPI_TX_EN,
			sspi->base + sspi->regs->tx_rx_en);
		if (sspi->type == SIRF_USP_SPI_P2 ||
			sspi->type == SIRF_USP_SPI_A7) {
			writel(SIRFSOC_SPI_FIFO_START,
				sspi->base + sspi->regs->rxfifo_op);
			writel(SIRFSOC_SPI_FIFO_START,
				sspi->base + sspi->regs->txfifo_op);
		}
		if (!wait_for_completion_timeout(&sspi->tx_done, timeout) ||
			!wait_for_completion_timeout(&sspi->rx_done, timeout)) {
			dev_err(&spi->dev, "transfer timeout\n");
			if (sspi->type == SIRF_USP_SPI_P2 ||
				sspi->type == SIRF_USP_SPI_A7)
				writel(0, sspi->base + sspi->regs->tx_rx_en);
			break;
		}
		while (!((readl(sspi->base + sspi->regs->rxfifo_st)
			& SIRFSOC_SPI_FIFO_EMPTY_MASK(sspi))) &&
			sspi->left_rx_word)
			sspi->rx_word(sspi);
		if (sspi->type == SIRF_USP_SPI_P2 ||
			sspi->type == SIRF_USP_SPI_A7)
			writel(0, sspi->base + sspi->regs->tx_rx_en);
		writel(0, sspi->base + sspi->regs->rxfifo_op);
		writel(0, sspi->base + sspi->regs->txfifo_op);
	} while (sspi->left_tx_word != 0 || sspi->left_rx_word != 0);
}

static int spi_sirfsoc_transfer(struct spi_device *spi, struct spi_transfer *t)
{
	struct sirfsoc_spi *sspi;

	sspi = spi_master_get_devdata(spi->master);
	sspi->tx = t->tx_buf;
	sspi->rx = t->rx_buf;
	sspi->left_tx_word = sspi->left_rx_word = t->len / sspi->word_width;
	reinit_completion(&sspi->rx_done);
	reinit_completion(&sspi->tx_done);
	/*
	 * in the transfer, if transfer data using command register with rx_buf
	 * null, just fill command data into command register and wait for its
	 * completion.
	 */
	if (sspi->type == SIRF_REAL_SPI && sspi->tx_by_cmd)
		spi_sirfsoc_cmd_transfer(spi, t);
	else if (IS_DMA_VALID(t))
		spi_sirfsoc_dma_transfer(spi, t);
	else
		spi_sirfsoc_pio_transfer(spi, t);

	return t->len - sspi->left_rx_word * sspi->word_width;
}

static void spi_sirfsoc_chipselect(struct spi_device *spi, int value)
{
	struct sirfsoc_spi *sspi = spi_master_get_devdata(spi->master);

	if (sspi->hw_cs) {
		u32 regval;

		switch (sspi->type) {
		case SIRF_REAL_SPI:
			regval = readl(sspi->base + sspi->regs->spi_ctrl);
			switch (value) {
			case BITBANG_CS_ACTIVE:
				if (spi->mode & SPI_CS_HIGH)
					regval |= SIRFSOC_SPI_CS_IO_OUT;
				else
					regval &= ~SIRFSOC_SPI_CS_IO_OUT;
				break;
			case BITBANG_CS_INACTIVE:
				if (spi->mode & SPI_CS_HIGH)
					regval &= ~SIRFSOC_SPI_CS_IO_OUT;
				else
					regval |= SIRFSOC_SPI_CS_IO_OUT;
				break;
			}
			writel(regval, sspi->base + sspi->regs->spi_ctrl);
			break;
		case SIRF_USP_SPI_P2:
		case SIRF_USP_SPI_A7:
			regval = readl(sspi->base +
					sspi->regs->usp_pin_io_data);
			switch (value) {
			case BITBANG_CS_ACTIVE:
				if (spi->mode & SPI_CS_HIGH)
					regval |= SIRFSOC_USP_CS_HIGH_VALUE;
				else
					regval &= ~(SIRFSOC_USP_CS_HIGH_VALUE);
				break;
			case BITBANG_CS_INACTIVE:
				if (spi->mode & SPI_CS_HIGH)
					regval &= ~(SIRFSOC_USP_CS_HIGH_VALUE);
				else
					regval |= SIRFSOC_USP_CS_HIGH_VALUE;
				break;
			}
			writel(regval,
				sspi->base + sspi->regs->usp_pin_io_data);
			break;
		}
	} else {
		switch (value) {
		case BITBANG_CS_ACTIVE:
			gpio_direction_output(spi->cs_gpio,
					spi->mode & SPI_CS_HIGH ? 1 : 0);
			break;
		case BITBANG_CS_INACTIVE:
			gpio_direction_output(spi->cs_gpio,
					spi->mode & SPI_CS_HIGH ? 0 : 1);
			break;
		}
	}
}

static int spi_sirfsoc_config_mode(struct spi_device *spi)
{
	struct sirfsoc_spi *sspi;
	u32 regval, usp_mode1;

	sspi = spi_master_get_devdata(spi->master);
	regval = readl(sspi->base + sspi->regs->spi_ctrl);
	usp_mode1 = readl(sspi->base + sspi->regs->usp_mode1);
	if (!(spi->mode & SPI_CS_HIGH)) {
		regval |= SIRFSOC_SPI_CS_IDLE_STAT;
		usp_mode1 &= ~SIRFSOC_USP_CS_HIGH_VALID;
	} else {
		regval &= ~SIRFSOC_SPI_CS_IDLE_STAT;
		usp_mode1 |= SIRFSOC_USP_CS_HIGH_VALID;
	}
	if (!(spi->mode & SPI_LSB_FIRST)) {
		regval |= SIRFSOC_SPI_TRAN_MSB;
		usp_mode1 &= ~SIRFSOC_USP_LSB;
	} else {
		regval &= ~SIRFSOC_SPI_TRAN_MSB;
		usp_mode1 |= SIRFSOC_USP_LSB;
	}
	if (spi->mode & SPI_CPOL) {
		regval |= SIRFSOC_SPI_CLK_IDLE_STAT;
		usp_mode1 |= SIRFSOC_USP_SCLK_IDLE_STAT;
	} else {
		regval &= ~SIRFSOC_SPI_CLK_IDLE_STAT;
		usp_mode1 &= ~SIRFSOC_USP_SCLK_IDLE_STAT;
	}
	/*
	 * Data should be driven at least 1/2 cycle before the fetch edge
	 * to make sure that data gets stable at the fetch edge.
	 */
	if (((spi->mode & SPI_CPOL) && (spi->mode & SPI_CPHA)) ||
	    (!(spi->mode & SPI_CPOL) && !(spi->mode & SPI_CPHA))) {
		regval &= ~SIRFSOC_SPI_DRV_POS_EDGE;
		usp_mode1 |= (SIRFSOC_USP_TXD_FALLING_EDGE |
				SIRFSOC_USP_RXD_FALLING_EDGE);
	} else {
		regval |= SIRFSOC_SPI_DRV_POS_EDGE;
		usp_mode1 &= ~(SIRFSOC_USP_RXD_FALLING_EDGE |
				SIRFSOC_USP_TXD_FALLING_EDGE);
	}
	writel((SIRFSOC_SPI_FIFO_LEVEL_CHK_MASK(sspi, sspi->fifo_size - 2) <<
		SIRFSOC_SPI_FIFO_SC_OFFSET) |
		(SIRFSOC_SPI_FIFO_LEVEL_CHK_MASK(sspi, sspi->fifo_size / 2) <<
		SIRFSOC_SPI_FIFO_LC_OFFSET) |
		(SIRFSOC_SPI_FIFO_LEVEL_CHK_MASK(sspi, 2) <<
		SIRFSOC_SPI_FIFO_HC_OFFSET),
		sspi->base + sspi->regs->txfifo_level_chk);
	writel((SIRFSOC_SPI_FIFO_LEVEL_CHK_MASK(sspi, 2) <<
		SIRFSOC_SPI_FIFO_SC_OFFSET) |
		(SIRFSOC_SPI_FIFO_LEVEL_CHK_MASK(sspi, sspi->fifo_size / 2) <<
		SIRFSOC_SPI_FIFO_LC_OFFSET) |
		(SIRFSOC_SPI_FIFO_LEVEL_CHK_MASK(sspi, sspi->fifo_size - 2) <<
		SIRFSOC_SPI_FIFO_HC_OFFSET),
		sspi->base + sspi->regs->rxfifo_level_chk);
	/*
	 * it should never set to hardware cs mode because in hardware cs mode,
	 * cs signal can't controlled by driver.
	 */
	switch (sspi->type) {
	case SIRF_REAL_SPI:
		regval |= SIRFSOC_SPI_CS_IO_MODE;
		writel(regval, sspi->base + sspi->regs->spi_ctrl);
		break;
	case SIRF_USP_SPI_P2:
	case SIRF_USP_SPI_A7:
		usp_mode1 |= SIRFSOC_USP_SYNC_MODE;
		usp_mode1 |= SIRFSOC_USP_TFS_IO_MODE;
		usp_mode1 &= ~SIRFSOC_USP_TFS_IO_INPUT;
		writel(usp_mode1, sspi->base + sspi->regs->usp_mode1);
		break;
	}

	return 0;
}

static int
spi_sirfsoc_setup_transfer(struct spi_device *spi, struct spi_transfer *t)
{
	struct sirfsoc_spi *sspi;
	u8 bits_per_word = 0;
	int hz = 0;
	u32 regval, txfifo_ctrl, rxfifo_ctrl, tx_frm_ctl, rx_frm_ctl, usp_mode2;

	sspi = spi_master_get_devdata(spi->master);

	bits_per_word = (t) ? t->bits_per_word : spi->bits_per_word;
	hz = t && t->speed_hz ? t->speed_hz : spi->max_speed_hz;

	usp_mode2 = regval = (sspi->ctrl_freq / (2 * hz)) - 1;
	if (regval > 0xFFFF || regval < 0) {
		dev_err(&spi->dev, "Speed %d not supported\n", hz);
		return -EINVAL;
	}
	switch (bits_per_word) {
	case 8:
		regval |= SIRFSOC_SPI_TRAN_DAT_FORMAT_8;
		sspi->rx_word = spi_sirfsoc_rx_word_u8;
		sspi->tx_word = spi_sirfsoc_tx_word_u8;
		break;
	case 12:
	case 16:
		regval |= (bits_per_word ==  12) ?
			SIRFSOC_SPI_TRAN_DAT_FORMAT_12 :
			SIRFSOC_SPI_TRAN_DAT_FORMAT_16;
		sspi->rx_word = spi_sirfsoc_rx_word_u16;
		sspi->tx_word = spi_sirfsoc_tx_word_u16;
		break;
	case 32:
		regval |= SIRFSOC_SPI_TRAN_DAT_FORMAT_32;
		sspi->rx_word = spi_sirfsoc_rx_word_u32;
		sspi->tx_word = spi_sirfsoc_tx_word_u32;
		break;
	default:
		dev_err(&spi->dev, "bpw %d not supported\n", bits_per_word);
		return -EINVAL;
	}
	sspi->word_width = DIV_ROUND_UP(bits_per_word, 8);
	txfifo_ctrl = (((sspi->fifo_size / 2) &
			SIRFSOC_SPI_FIFO_THD_MASK(sspi))
			<< SIRFSOC_SPI_FIFO_THD_OFFSET) |
			(sspi->word_width >> 1);
	rxfifo_ctrl = (((sspi->fifo_size / 2) &
			SIRFSOC_SPI_FIFO_THD_MASK(sspi))
			<< SIRFSOC_SPI_FIFO_THD_OFFSET) |
			(sspi->word_width >> 1);
	writel(txfifo_ctrl, sspi->base + sspi->regs->txfifo_ctrl);
	writel(rxfifo_ctrl, sspi->base + sspi->regs->rxfifo_ctrl);
	if (sspi->type == SIRF_USP_SPI_P2 ||
		sspi->type == SIRF_USP_SPI_A7) {
		tx_frm_ctl = 0;
		tx_frm_ctl |= ((bits_per_word - 1) & SIRFSOC_USP_TX_DATA_MASK)
				<< SIRFSOC_USP_TX_DATA_OFFSET;
		tx_frm_ctl |= ((bits_per_word + 1 + SIRFSOC_USP_TXD_DELAY_LEN
				- 1) & SIRFSOC_USP_TX_SYNC_MASK) <<
				SIRFSOC_USP_TX_SYNC_OFFSET;
		tx_frm_ctl |= ((bits_per_word + 1 + SIRFSOC_USP_TXD_DELAY_LEN
				+ 2 - 1) & SIRFSOC_USP_TX_FRAME_MASK) <<
				SIRFSOC_USP_TX_FRAME_OFFSET;
		tx_frm_ctl |= ((bits_per_word - 1) &
				SIRFSOC_USP_TX_SHIFTER_MASK) <<
				SIRFSOC_USP_TX_SHIFTER_OFFSET;
		rx_frm_ctl = 0;
		rx_frm_ctl |= ((bits_per_word - 1) & SIRFSOC_USP_RX_DATA_MASK)
				<< SIRFSOC_USP_RX_DATA_OFFSET;
		rx_frm_ctl |= ((bits_per_word + 1 + SIRFSOC_USP_RXD_DELAY_LEN
				+ 2 - 1) & SIRFSOC_USP_RX_FRAME_MASK) <<
				SIRFSOC_USP_RX_FRAME_OFFSET;
		rx_frm_ctl |= ((bits_per_word - 1)
				& SIRFSOC_USP_RX_SHIFTER_MASK) <<
				SIRFSOC_USP_RX_SHIFTER_OFFSET;
		writel(tx_frm_ctl | (((usp_mode2 >> 10) &
			SIRFSOC_USP_CLK_10_11_MASK) <<
			SIRFSOC_USP_CLK_10_11_OFFSET),
			sspi->base + sspi->regs->usp_tx_frame_ctrl);
		writel(rx_frm_ctl | (((usp_mode2 >> 12) &
			SIRFSOC_USP_CLK_12_15_MASK) <<
			SIRFSOC_USP_CLK_12_15_OFFSET),
			sspi->base + sspi->regs->usp_rx_frame_ctrl);
		writel(readl(sspi->base + sspi->regs->usp_mode2) |
			((usp_mode2 & SIRFSOC_USP_CLK_DIVISOR_MASK) <<
			SIRFSOC_USP_CLK_DIVISOR_OFFSET) |
			(SIRFSOC_USP_RXD_DELAY_LEN <<
			 SIRFSOC_USP_RXD_DELAY_OFFSET) |
			(SIRFSOC_USP_TXD_DELAY_LEN <<
			 SIRFSOC_USP_TXD_DELAY_OFFSET),
			sspi->base + sspi->regs->usp_mode2);
	}
	if (sspi->type == SIRF_REAL_SPI)
		writel(regval, sspi->base + sspi->regs->spi_ctrl);
	spi_sirfsoc_config_mode(spi);
	if (sspi->type == SIRF_REAL_SPI) {
		if (t && t->tx_buf && !t->rx_buf &&
			(t->len <= SIRFSOC_MAX_CMD_BYTES)) {
			sspi->tx_by_cmd = true;
			writel(readl(sspi->base + sspi->regs->spi_ctrl) |
				(SIRFSOC_SPI_CMD_BYTE_NUM((t->len - 1)) |
				SIRFSOC_SPI_CMD_MODE),
				sspi->base + sspi->regs->spi_ctrl);
		} else {
			sspi->tx_by_cmd = false;
			writel(readl(sspi->base + sspi->regs->spi_ctrl) &
				~SIRFSOC_SPI_CMD_MODE,
				sspi->base + sspi->regs->spi_ctrl);
		}
	}
	if (IS_DMA_VALID(t)) {
		/* Enable DMA mode for RX, TX */
		writel(0, sspi->base + sspi->regs->tx_dma_io_ctrl);
		writel(SIRFSOC_SPI_RX_DMA_FLUSH,
			sspi->base + sspi->regs->rx_dma_io_ctrl);
	} else {
		/* Enable IO mode for RX, TX */
		writel(SIRFSOC_SPI_IO_MODE_SEL,
			sspi->base + sspi->regs->tx_dma_io_ctrl);
		writel(SIRFSOC_SPI_IO_MODE_SEL,
			sspi->base + sspi->regs->rx_dma_io_ctrl);
	}
	return 0;
}

static int spi_sirfsoc_setup(struct spi_device *spi)
{
	struct sirfsoc_spi *sspi;
	int ret = 0;

	sspi = spi_master_get_devdata(spi->master);
	if (spi->cs_gpio == -ENOENT)
		sspi->hw_cs = true;
	else {
		sspi->hw_cs = false;
		if (!spi_get_ctldata(spi)) {
			void *cs = kmalloc(sizeof(int), GFP_KERNEL);
			if (!cs) {
				ret = -ENOMEM;
				goto exit;
			}
			ret = gpio_is_valid(spi->cs_gpio);
			if (!ret) {
				dev_err(&spi->dev, "no valid gpio\n");
				ret = -ENOENT;
				goto exit;
			}
			ret = gpio_request(spi->cs_gpio, DRIVER_NAME);
			if (ret) {
				dev_err(&spi->dev, "failed to request gpio\n");
				goto exit;
			}
			spi_set_ctldata(spi, cs);
		}
	}
	spi_sirfsoc_config_mode(spi);
	spi_sirfsoc_chipselect(spi, BITBANG_CS_INACTIVE);
exit:
	return ret;
}

static void spi_sirfsoc_cleanup(struct spi_device *spi)
{
	if (spi_get_ctldata(spi)) {
		gpio_free(spi->cs_gpio);
		kfree(spi_get_ctldata(spi));
	}
}

static const struct sirf_spi_comp_data sirf_real_spi = {
	.regs = &real_spi_register,
	.type = SIRF_REAL_SPI,
	.dat_max_frm_len = 64 * 1024,
	.fifo_size = 256,
};

static const struct sirf_spi_comp_data sirf_usp_spi_p2 = {
	.regs = &usp_spi_register,
	.type = SIRF_USP_SPI_P2,
	.dat_max_frm_len = 1024 * 1024,
	.fifo_size = 128,
	.hwinit = sirfsoc_usp_hwinit,
};

static const struct sirf_spi_comp_data sirf_usp_spi_a7 = {
	.regs = &usp_spi_register,
	.type = SIRF_USP_SPI_A7,
	.dat_max_frm_len = 1024 * 1024,
	.fifo_size = 512,
	.hwinit = sirfsoc_usp_hwinit,
};

static const struct of_device_id spi_sirfsoc_of_match[] = {
	{ .compatible = "sirf,prima2-spi", .data = &sirf_real_spi},
	{ .compatible = "sirf,prima2-usp-spi", .data = &sirf_usp_spi_p2},
	{ .compatible = "sirf,atlas7-usp-spi", .data = &sirf_usp_spi_a7},
	{}
};
MODULE_DEVICE_TABLE(of, spi_sirfsoc_of_match);

static int spi_sirfsoc_probe(struct platform_device *pdev)
{
	struct sirfsoc_spi *sspi;
	struct spi_master *master;
	struct resource *mem_res;
	struct sirf_spi_comp_data *spi_comp_data;
	int irq;
	int ret;
	const struct of_device_id *match;

	ret = device_reset(&pdev->dev);
	if (ret) {
		dev_err(&pdev->dev, "SPI reset failed!\n");
		return ret;
	}

	master = spi_alloc_master(&pdev->dev, sizeof(*sspi));
	if (!master) {
		dev_err(&pdev->dev, "Unable to allocate SPI master\n");
		return -ENOMEM;
	}
	match = of_match_node(spi_sirfsoc_of_match, pdev->dev.of_node);
	platform_set_drvdata(pdev, master);
	sspi = spi_master_get_devdata(master);
	sspi->fifo_full_offset = ilog2(sspi->fifo_size);
	spi_comp_data = (struct sirf_spi_comp_data *)match->data;
	sspi->regs = spi_comp_data->regs;
	sspi->type = spi_comp_data->type;
	sspi->fifo_level_chk_mask = (sspi->fifo_size / 4) - 1;
	sspi->dat_max_frm_len = spi_comp_data->dat_max_frm_len;
	sspi->fifo_size = spi_comp_data->fifo_size;
	mem_res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
	sspi->base = devm_ioremap_resource(&pdev->dev, mem_res);
	if (IS_ERR(sspi->base)) {
		ret = PTR_ERR(sspi->base);
		goto free_master;
	}
	irq = platform_get_irq(pdev, 0);
	if (irq < 0) {
		ret = -ENXIO;
		goto free_master;
	}
	ret = devm_request_irq(&pdev->dev, irq, spi_sirfsoc_irq, 0,
				DRIVER_NAME, sspi);
	if (ret)
		goto free_master;

	sspi->bitbang.master = master;
	sspi->bitbang.chipselect = spi_sirfsoc_chipselect;
	sspi->bitbang.setup_transfer = spi_sirfsoc_setup_transfer;
	sspi->bitbang.txrx_bufs = spi_sirfsoc_transfer;
	sspi->bitbang.master->setup = spi_sirfsoc_setup;
	sspi->bitbang.master->cleanup = spi_sirfsoc_cleanup;
	master->bus_num = pdev->id;
	master->mode_bits = SPI_CPOL | SPI_CPHA | SPI_LSB_FIRST | SPI_CS_HIGH;
	master->bits_per_word_mask = SPI_BPW_MASK(8) | SPI_BPW_MASK(12) |
					SPI_BPW_MASK(16) | SPI_BPW_MASK(32);
	master->max_speed_hz = SIRFSOC_SPI_DEFAULT_FRQ;
	master->flags = SPI_MASTER_MUST_RX | SPI_MASTER_MUST_TX;
	sspi->bitbang.master->dev.of_node = pdev->dev.of_node;

	/* request DMA channels */
	sspi->rx_chan = dma_request_slave_channel(&pdev->dev, "rx");
	if (!sspi->rx_chan) {
		dev_err(&pdev->dev, "can not allocate rx dma channel\n");
		ret = -ENODEV;
		goto free_master;
	}
	sspi->tx_chan = dma_request_slave_channel(&pdev->dev, "tx");
	if (!sspi->tx_chan) {
		dev_err(&pdev->dev, "can not allocate tx dma channel\n");
		ret = -ENODEV;
		goto free_rx_dma;
	}

	sspi->clk = clk_get(&pdev->dev, NULL);
	if (IS_ERR(sspi->clk)) {
		ret = PTR_ERR(sspi->clk);
		goto free_tx_dma;
	}
	clk_prepare_enable(sspi->clk);
	if (spi_comp_data->hwinit)
		spi_comp_data->hwinit(sspi);
	sspi->ctrl_freq = clk_get_rate(sspi->clk);

	init_completion(&sspi->rx_done);
	init_completion(&sspi->tx_done);

	ret = spi_bitbang_start(&sspi->bitbang);
	if (ret)
		goto free_clk;
	dev_info(&pdev->dev, "registered, bus number = %d\n", master->bus_num);

	return 0;
free_clk:
	clk_disable_unprepare(sspi->clk);
	clk_put(sspi->clk);
free_tx_dma:
	dma_release_channel(sspi->tx_chan);
free_rx_dma:
	dma_release_channel(sspi->rx_chan);
free_master:
	spi_master_put(master);

	return ret;
}

static int  spi_sirfsoc_remove(struct platform_device *pdev)
{
	struct spi_master *master;
	struct sirfsoc_spi *sspi;

	master = platform_get_drvdata(pdev);
	sspi = spi_master_get_devdata(master);
	spi_bitbang_stop(&sspi->bitbang);
	clk_disable_unprepare(sspi->clk);
	clk_put(sspi->clk);
	dma_release_channel(sspi->rx_chan);
	dma_release_channel(sspi->tx_chan);
	spi_master_put(master);
	return 0;
}

#ifdef CONFIG_PM_SLEEP
static int spi_sirfsoc_suspend(struct device *dev)
{
	struct spi_master *master = dev_get_drvdata(dev);
	struct sirfsoc_spi *sspi = spi_master_get_devdata(master);
	int ret;

	ret = spi_master_suspend(master);
	if (ret)
		return ret;

	clk_disable(sspi->clk);
	return 0;
}

static int spi_sirfsoc_resume(struct device *dev)
{
	struct spi_master *master = dev_get_drvdata(dev);
	struct sirfsoc_spi *sspi = spi_master_get_devdata(master);

	clk_enable(sspi->clk);
	writel(SIRFSOC_SPI_FIFO_RESET, sspi->base + sspi->regs->txfifo_op);
	writel(SIRFSOC_SPI_FIFO_RESET, sspi->base + sspi->regs->rxfifo_op);
	writel(SIRFSOC_SPI_FIFO_START, sspi->base + sspi->regs->txfifo_op);
	writel(SIRFSOC_SPI_FIFO_START, sspi->base + sspi->regs->rxfifo_op);
	return 0;
}
#endif

static SIMPLE_DEV_PM_OPS(spi_sirfsoc_pm_ops, spi_sirfsoc_suspend,
			 spi_sirfsoc_resume);

static struct platform_driver spi_sirfsoc_driver = {
	.driver = {
		.name = DRIVER_NAME,
		.pm     = &spi_sirfsoc_pm_ops,
		.of_match_table = spi_sirfsoc_of_match,
	},
	.probe = spi_sirfsoc_probe,
	.remove = spi_sirfsoc_remove,
};
module_platform_driver(spi_sirfsoc_driver);
MODULE_DESCRIPTION("SiRF SoC SPI master driver");
MODULE_AUTHOR("Zhiwu Song <Zhiwu.Song@csr.com>");
MODULE_AUTHOR("Barry Song <Baohua.Song@csr.com>");
MODULE_AUTHOR("Qipan Li <Qipan.Li@csr.com>");
MODULE_LICENSE("GPL v2");