SPI: add CSR SiRFprimaII SPI controller driver

CSR SiRFprimaII has two SPIs (SPI0 and SPI1). Features:
* Master and slave modes
* 8-/12-/16-/32-bit data unit
* 256 bytes receive data FIFO and 256 bytes transmit data FIFO
* Multi-unit frame
* Configurable SPI_EN (chip select pin) active state
* Configurable SPI_CLK polarity
* Configurable SPI_CLK phase
* Configurable MSB/LSB first

Signed-off-by: Zhiwu Song <zhiwu.song@csr.com>
Signed-off-by: Barry Song <Baohua.Song@csr.com>
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>

1 files changed, 687 insertions, 0 deletions

diff --git a/drivers/spi/spi-sirf.c b/drivers/spi/spi-sirf.c
new file mode 100644
index 000000000000..52fe495bb32a
--- /dev/null
+++ b/drivers/spi/spi-sirf.c
@@ -0,0 +1,687 @@
+/*
+ * 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/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/pinctrl/pinmux.h>
+
+#define DRIVER_NAME "sirfsoc_spi"
+
+#define SIRFSOC_SPI_CTRL		0x0000
+#define SIRFSOC_SPI_CMD			0x0004
+#define SIRFSOC_SPI_TX_RX_EN		0x0008
+#define SIRFSOC_SPI_INT_EN		0x000C
+#define SIRFSOC_SPI_INT_STATUS		0x0010
+#define SIRFSOC_SPI_TX_DMA_IO_CTRL	0x0100
+#define SIRFSOC_SPI_TX_DMA_IO_LEN	0x0104
+#define SIRFSOC_SPI_TXFIFO_CTRL		0x0108
+#define SIRFSOC_SPI_TXFIFO_LEVEL_CHK	0x010C
+#define SIRFSOC_SPI_TXFIFO_OP		0x0110
+#define SIRFSOC_SPI_TXFIFO_STATUS	0x0114
+#define SIRFSOC_SPI_TXFIFO_DATA		0x0118
+#define SIRFSOC_SPI_RX_DMA_IO_CTRL	0x0120
+#define SIRFSOC_SPI_RX_DMA_IO_LEN	0x0124
+#define SIRFSOC_SPI_RXFIFO_CTRL		0x0128
+#define SIRFSOC_SPI_RXFIFO_LEVEL_CHK	0x012C
+#define SIRFSOC_SPI_RXFIFO_OP		0x0130
+#define SIRFSOC_SPI_RXFIFO_STATUS	0x0134
+#define SIRFSOC_SPI_RXFIFO_DATA		0x0138
+#define SIRFSOC_SPI_DUMMY_DELAY_CTL	0x0144
+
+/* 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)
+
+#define SIRFSOC_SPI_INT_MASK_ALL		0x1FFF
+
+/* 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_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)
+
+/* FIFO Status */
+#define	SIRFSOC_SPI_FIFO_LEVEL_MASK	0xFF
+#define SIRFSOC_SPI_FIFO_FULL		BIT(8)
+#define SIRFSOC_SPI_FIFO_EMPTY		BIT(9)
+
+/* 256 bytes rx/tx FIFO */
+#define SIRFSOC_SPI_FIFO_SIZE		256
+#define SIRFSOC_SPI_DAT_FRM_LEN_MAX	(64 * 1024)
+
+#define SIRFSOC_SPI_FIFO_SC(x)		((x) & 0x3F)
+#define SIRFSOC_SPI_FIFO_LC(x)		(((x) & 0x3F) << 10)
+#define SIRFSOC_SPI_FIFO_HC(x)		(((x) & 0x3F) << 20)
+#define SIRFSOC_SPI_FIFO_THD(x)		(((x) & 0xFF) << 2)
+
+struct sirfsoc_spi {
+	struct spi_bitbang bitbang;
+	struct completion done;
+
+	void __iomem *base;
+	u32 ctrl_freq;  /* SPI controller clock speed */
+	struct clk *clk;
+	struct pinmux *pmx;
+
+	/* 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_cnt;
+	unsigned int left_rx_cnt;
+
+	/* tasklet to push tx msg into FIFO */
+	struct tasklet_struct tasklet_tx;
+
+	int chipselect[0];
+};
+
+static void spi_sirfsoc_rx_word_u8(struct sirfsoc_spi *sspi)
+{
+	u32 data;
+	u8 *rx = sspi->rx;
+
+	data = readl(sspi->base + SIRFSOC_SPI_RXFIFO_DATA);
+
+	if (rx) {
+		*rx++ = (u8) data;
+		sspi->rx = rx;
+	}
+
+	sspi->left_rx_cnt--;
+}
+
+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 + SIRFSOC_SPI_TXFIFO_DATA);
+	sspi->left_tx_cnt--;
+}
+
+static void spi_sirfsoc_rx_word_u16(struct sirfsoc_spi *sspi)
+{
+	u32 data;
+	u16 *rx = sspi->rx;
+
+	data = readl(sspi->base + SIRFSOC_SPI_RXFIFO_DATA);
+
+	if (rx) {
+		*rx++ = (u16) data;
+		sspi->rx = rx;
+	}
+
+	sspi->left_rx_cnt--;
+}
+
+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 + SIRFSOC_SPI_TXFIFO_DATA);
+	sspi->left_tx_cnt--;
+}
+
+static void spi_sirfsoc_rx_word_u32(struct sirfsoc_spi *sspi)
+{
+	u32 data;
+	u32 *rx = sspi->rx;
+
+	data = readl(sspi->base + SIRFSOC_SPI_RXFIFO_DATA);
+
+	if (rx) {
+		*rx++ = (u32) data;
+		sspi->rx = rx;
+	}
+
+	sspi->left_rx_cnt--;
+
+}
+
+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 + SIRFSOC_SPI_TXFIFO_DATA);
+	sspi->left_tx_cnt--;
+}
+
+static void spi_sirfsoc_tasklet_tx(unsigned long arg)
+{
+	struct sirfsoc_spi *sspi = (struct sirfsoc_spi *)arg;
+
+	/* Fill Tx FIFO while there are left words to be transmitted */
+	while (!((readl(sspi->base + SIRFSOC_SPI_TXFIFO_STATUS) &
+			SIRFSOC_SPI_FIFO_FULL)) &&
+			sspi->left_tx_cnt)
+		sspi->tx_word(sspi);
+}
+
+static irqreturn_t spi_sirfsoc_irq(int irq, void *dev_id)
+{
+	struct sirfsoc_spi *sspi = dev_id;
+	u32 spi_stat = readl(sspi->base + SIRFSOC_SPI_INT_STATUS);
+
+	writel(spi_stat, sspi->base + SIRFSOC_SPI_INT_STATUS);
+
+	/* Error Conditions */
+	if (spi_stat & SIRFSOC_SPI_RX_OFLOW ||
+			spi_stat & SIRFSOC_SPI_TX_UFLOW) {
+		complete(&sspi->done);
+		writel(0x0, sspi->base + SIRFSOC_SPI_INT_EN);
+	}
+
+	if (spi_stat & SIRFSOC_SPI_FRM_END) {
+		while (!((readl(sspi->base + SIRFSOC_SPI_RXFIFO_STATUS)
+				& SIRFSOC_SPI_FIFO_EMPTY)) &&
+				sspi->left_rx_cnt)
+			sspi->rx_word(sspi);
+
+		/* Received all words */
+		if ((sspi->left_rx_cnt == 0) && (sspi->left_tx_cnt == 0)) {
+			complete(&sspi->done);
+			writel(0x0, sspi->base + SIRFSOC_SPI_INT_EN);
+		}
+	}
+
+	if (spi_stat & SIRFSOC_SPI_RXFIFO_THD_REACH ||
+		spi_stat & SIRFSOC_SPI_TXFIFO_THD_REACH ||
+		spi_stat & SIRFSOC_SPI_RX_FIFO_FULL ||
+		spi_stat & SIRFSOC_SPI_TXFIFO_EMPTY)
+		tasklet_schedule(&sspi->tasklet_tx);
+
+	return IRQ_HANDLED;
+}
+
+static int spi_sirfsoc_transfer(struct spi_device *spi, struct spi_transfer *t)
+{
+	struct sirfsoc_spi *sspi;
+	int timeout = t->len * 10;
+	sspi = spi_master_get_devdata(spi->master);
+
+	sspi->tx = t->tx_buf;
+	sspi->rx = t->rx_buf;
+	sspi->left_tx_cnt = sspi->left_rx_cnt = t->len;
+	INIT_COMPLETION(sspi->done);
+
+	writel(SIRFSOC_SPI_INT_MASK_ALL, sspi->base + SIRFSOC_SPI_INT_STATUS);
+
+	if (t->len == 1) {
+		writel(readl(sspi->base + SIRFSOC_SPI_CTRL) |
+			SIRFSOC_SPI_ENA_AUTO_CLR,
+			sspi->base + SIRFSOC_SPI_CTRL);
+		writel(0, sspi->base + SIRFSOC_SPI_TX_DMA_IO_LEN);
+		writel(0, sspi->base + SIRFSOC_SPI_RX_DMA_IO_LEN);
+	} else if ((t->len > 1) && (t->len < SIRFSOC_SPI_DAT_FRM_LEN_MAX)) {
+		writel(readl(sspi->base + SIRFSOC_SPI_CTRL) |
+				SIRFSOC_SPI_MUL_DAT_MODE |
+				SIRFSOC_SPI_ENA_AUTO_CLR,
+			sspi->base + SIRFSOC_SPI_CTRL);
+		writel(t->len - 1, sspi->base + SIRFSOC_SPI_TX_DMA_IO_LEN);
+		writel(t->len - 1, sspi->base + SIRFSOC_SPI_RX_DMA_IO_LEN);
+	} else {
+		writel(readl(sspi->base + SIRFSOC_SPI_CTRL),
+			sspi->base + SIRFSOC_SPI_CTRL);
+		writel(0, sspi->base + SIRFSOC_SPI_TX_DMA_IO_LEN);
+		writel(0, sspi->base + SIRFSOC_SPI_RX_DMA_IO_LEN);
+	}
+
+	writel(SIRFSOC_SPI_FIFO_RESET, sspi->base + SIRFSOC_SPI_RXFIFO_OP);
+	writel(SIRFSOC_SPI_FIFO_RESET, sspi->base + SIRFSOC_SPI_TXFIFO_OP);
+	writel(SIRFSOC_SPI_FIFO_START, sspi->base + SIRFSOC_SPI_RXFIFO_OP);
+	writel(SIRFSOC_SPI_FIFO_START, sspi->base + SIRFSOC_SPI_TXFIFO_OP);
+
+	/* Send the first word to trigger the whole tx/rx process */
+	sspi->tx_word(sspi);
+
+	writel(SIRFSOC_SPI_RX_OFLOW_INT_EN | SIRFSOC_SPI_TX_UFLOW_INT_EN |
+		SIRFSOC_SPI_RXFIFO_THD_INT_EN | SIRFSOC_SPI_TXFIFO_THD_INT_EN |
+		SIRFSOC_SPI_FRM_END_INT_EN | SIRFSOC_SPI_RXFIFO_FULL_INT_EN |
+		SIRFSOC_SPI_TXFIFO_EMPTY_INT_EN, sspi->base + SIRFSOC_SPI_INT_EN);
+	writel(SIRFSOC_SPI_RX_EN | SIRFSOC_SPI_TX_EN, sspi->base + SIRFSOC_SPI_TX_RX_EN);
+
+	if (wait_for_completion_timeout(&sspi->done, timeout) == 0)
+		dev_err(&spi->dev, "transfer timeout\n");
+
+	/* TX, RX FIFO stop */
+	writel(0, sspi->base + SIRFSOC_SPI_RXFIFO_OP);
+	writel(0, sspi->base + SIRFSOC_SPI_TXFIFO_OP);
+	writel(0, sspi->base + SIRFSOC_SPI_TX_RX_EN);
+	writel(0, sspi->base + SIRFSOC_SPI_INT_EN);
+
+	return t->len - sspi->left_rx_cnt;
+}
+
+static void spi_sirfsoc_chipselect(struct spi_device *spi, int value)
+{
+	struct sirfsoc_spi *sspi = spi_master_get_devdata(spi->master);
+
+	if (sspi->chipselect[spi->chip_select] == 0) {
+		u32 regval = readl(sspi->base + SIRFSOC_SPI_CTRL);
+		regval |= SIRFSOC_SPI_CS_IO_OUT;
+		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 + SIRFSOC_SPI_CTRL);
+	} else {
+		int gpio = sspi->chipselect[spi->chip_select];
+		gpio_direction_output(gpio, spi->mode & SPI_CS_HIGH ? 0 : 1);
+	}
+}
+
+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;
+	u32 txfifo_ctrl, rxfifo_ctrl;
+	u32 fifo_size = SIRFSOC_SPI_FIFO_SIZE / 4;
+
+	sspi = spi_master_get_devdata(spi->master);
+
+	bits_per_word = t && t->bits_per_word ? t->bits_per_word :
+		spi->bits_per_word;
+	hz = t && t->speed_hz ? t->speed_hz : spi->max_speed_hz;
+
+	/* Enable IO mode for RX, TX */
+	writel(SIRFSOC_SPI_IO_MODE_SEL, sspi->base + SIRFSOC_SPI_TX_DMA_IO_CTRL);
+	writel(SIRFSOC_SPI_IO_MODE_SEL, sspi->base + SIRFSOC_SPI_RX_DMA_IO_CTRL);
+	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;
+		txfifo_ctrl = SIRFSOC_SPI_FIFO_THD(SIRFSOC_SPI_FIFO_SIZE / 2) |
+					SIRFSOC_SPI_FIFO_WIDTH_BYTE;
+		rxfifo_ctrl = SIRFSOC_SPI_FIFO_THD(SIRFSOC_SPI_FIFO_SIZE / 2) |
+					SIRFSOC_SPI_FIFO_WIDTH_BYTE;
+		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;
+		txfifo_ctrl = SIRFSOC_SPI_FIFO_THD(SIRFSOC_SPI_FIFO_SIZE / 2) |
+					SIRFSOC_SPI_FIFO_WIDTH_WORD;
+		rxfifo_ctrl = SIRFSOC_SPI_FIFO_THD(SIRFSOC_SPI_FIFO_SIZE / 2) |
+					SIRFSOC_SPI_FIFO_WIDTH_WORD;
+		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;
+		txfifo_ctrl = SIRFSOC_SPI_FIFO_THD(SIRFSOC_SPI_FIFO_SIZE / 2) |
+					SIRFSOC_SPI_FIFO_WIDTH_DWORD;
+		rxfifo_ctrl = SIRFSOC_SPI_FIFO_THD(SIRFSOC_SPI_FIFO_SIZE / 2) |
+					SIRFSOC_SPI_FIFO_WIDTH_DWORD;
+		break;
+	default:
+		dev_err(&spi->dev, "Bits per word %d not supported\n",
+		       bits_per_word);
+		return -EINVAL;
+	}
+
+	if (!(spi->mode & SPI_CS_HIGH))
+		regval |= SIRFSOC_SPI_CS_IDLE_STAT;
+	if (!(spi->mode & SPI_LSB_FIRST))
+		regval |= SIRFSOC_SPI_TRAN_MSB;
+	if (spi->mode & SPI_CPOL)
+		regval |= SIRFSOC_SPI_CLK_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;
+	else
+		regval |= SIRFSOC_SPI_DRV_POS_EDGE;
+
+	writel(SIRFSOC_SPI_FIFO_SC(fifo_size - 2) |
+			SIRFSOC_SPI_FIFO_LC(fifo_size / 2) |
+			SIRFSOC_SPI_FIFO_HC(2),
+		sspi->base + SIRFSOC_SPI_TXFIFO_LEVEL_CHK);
+	writel(SIRFSOC_SPI_FIFO_SC(2) |
+			SIRFSOC_SPI_FIFO_LC(fifo_size / 2) |
+			SIRFSOC_SPI_FIFO_HC(fifo_size - 2),
+		sspi->base + SIRFSOC_SPI_RXFIFO_LEVEL_CHK);
+	writel(txfifo_ctrl, sspi->base + SIRFSOC_SPI_TXFIFO_CTRL);
+	writel(rxfifo_ctrl, sspi->base + SIRFSOC_SPI_RXFIFO_CTRL);
+
+	writel(regval, sspi->base + SIRFSOC_SPI_CTRL);
+	return 0;
+}
+
+static int spi_sirfsoc_setup(struct spi_device *spi)
+{
+	struct sirfsoc_spi *sspi;
+
+	if (!spi->max_speed_hz)
+		return -EINVAL;
+
+	sspi = spi_master_get_devdata(spi->master);
+
+	if (!spi->bits_per_word)
+		spi->bits_per_word = 8;
+
+	return spi_sirfsoc_setup_transfer(spi, NULL);
+}
+
+static int __devinit spi_sirfsoc_probe(struct platform_device *pdev)
+{
+	struct sirfsoc_spi *sspi;
+	struct spi_master *master;
+	struct resource *mem_res;
+	int num_cs, cs_gpio, irq;
+	int i;
+	int ret;
+
+	ret = of_property_read_u32(pdev->dev.of_node,
+			"sirf,spi-num-chipselects", &num_cs);
+	if (ret < 0) {
+		dev_err(&pdev->dev, "Unable to get chip select number\n");
+		goto err_cs;
+	}
+
+	master = spi_alloc_master(&pdev->dev, sizeof(*sspi) + sizeof(int) * num_cs);
+	if (!master) {
+		dev_err(&pdev->dev, "Unable to allocate SPI master\n");
+		return -ENOMEM;
+	}
+	platform_set_drvdata(pdev, master);
+	sspi = spi_master_get_devdata(master);
+
+	mem_res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	if (!mem_res) {
+		dev_err(&pdev->dev, "Unable to get IO resource\n");
+		ret = -ENODEV;
+		goto free_master;
+	}
+	master->num_chipselect = num_cs;
+
+	for (i = 0; i < master->num_chipselect; i++) {
+		cs_gpio = of_get_named_gpio(pdev->dev.of_node, "cs-gpios", i);
+		if (cs_gpio < 0) {
+			dev_err(&pdev->dev, "can't get cs gpio from DT\n");
+			ret = -ENODEV;
+			goto free_master;
+		}
+
+		sspi->chipselect[i] = cs_gpio;
+		if (cs_gpio == 0)
+			continue; /* use cs from spi controller */
+
+		ret = gpio_request(cs_gpio, DRIVER_NAME);
+		if (ret) {
+			while (i > 0) {
+				i--;
+				if (sspi->chipselect[i] > 0)
+					gpio_free(sspi->chipselect[i]);
+			}
+			dev_err(&pdev->dev, "fail to request cs gpios\n");
+			goto free_master;
+		}
+	}
+
+	sspi->base = devm_request_and_ioremap(&pdev->dev, mem_res);
+	if (!sspi->base) {
+		dev_err(&pdev->dev, "IO remap failed!\n");
+		ret = -ENOMEM;
+		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 = spi_master_get(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;
+	master->bus_num = pdev->id;
+	sspi->bitbang.master->dev.of_node = pdev->dev.of_node;
+
+	sspi->pmx = pinmux_get(&pdev->dev, NULL);
+	ret = IS_ERR(sspi->pmx);
+	if (ret)
+		goto free_master;
+
+	pinmux_enable(sspi->pmx);
+
+	sspi->clk = clk_get(&pdev->dev, NULL);
+	if (IS_ERR(sspi->clk)) {
+		ret = -EINVAL;
+		goto free_pmx;
+	}
+	clk_enable(sspi->clk);
+	sspi->ctrl_freq = clk_get_rate(sspi->clk);
+
+	init_completion(&sspi->done);
+
+	tasklet_init(&sspi->tasklet_tx, spi_sirfsoc_tasklet_tx,
+		     (unsigned long)sspi);
+
+	writel(SIRFSOC_SPI_FIFO_RESET, sspi->base + SIRFSOC_SPI_RXFIFO_OP);
+	writel(SIRFSOC_SPI_FIFO_RESET, sspi->base + SIRFSOC_SPI_TXFIFO_OP);
+	writel(SIRFSOC_SPI_FIFO_START, sspi->base + SIRFSOC_SPI_RXFIFO_OP);
+	writel(SIRFSOC_SPI_FIFO_START, sspi->base + SIRFSOC_SPI_TXFIFO_OP);
+	/* We are not using dummy delay between command and data */
+	writel(0, sspi->base + SIRFSOC_SPI_DUMMY_DELAY_CTL);
+
+	ret = spi_bitbang_start(&sspi->bitbang);
+	if (ret)
+		goto free_clk;
+
+	dev_info(&pdev->dev, "registerred, bus number = %d\n", master->bus_num);
+
+	return 0;
+
+free_clk:
+	clk_disable(sspi->clk);
+	clk_put(sspi->clk);
+free_pmx:
+	pinmux_disable(sspi->pmx);
+	pinmux_put(sspi->pmx);
+free_master:
+	spi_master_put(master);
+err_cs:
+	return ret;
+}
+
+static int  __devexit spi_sirfsoc_remove(struct platform_device *pdev)
+{
+	struct spi_master *master;
+	struct sirfsoc_spi *sspi;
+	int i;
+
+	master = platform_get_drvdata(pdev);
+	sspi = spi_master_get_devdata(master);
+
+	spi_bitbang_stop(&sspi->bitbang);
+	for (i = 0; i < master->num_chipselect; i++) {
+		if (sspi->chipselect[i] > 0)
+			gpio_free(sspi->chipselect[i]);
+	}
+	clk_disable(sspi->clk);
+	clk_put(sspi->clk);
+	pinmux_disable(sspi->pmx);
+	pinmux_put(sspi->pmx);
+	spi_master_put(master);
+	return 0;
+}
+
+#ifdef CONFIG_PM
+static int spi_sirfsoc_suspend(struct device *dev)
+{
+	struct platform_device *pdev = to_platform_device(dev);
+	struct spi_master *master = platform_get_drvdata(pdev);
+	struct sirfsoc_spi *sspi = spi_master_get_devdata(master);
+
+	clk_disable(sspi->clk);
+	return 0;
+}
+
+static int spi_sirfsoc_resume(struct device *dev)
+{
+	struct platform_device *pdev = to_platform_device(dev);
+	struct spi_master *master = platform_get_drvdata(pdev);
+	struct sirfsoc_spi *sspi = spi_master_get_devdata(master);
+
+	clk_enable(sspi->clk);
+	writel(SIRFSOC_SPI_FIFO_RESET, sspi->base + SIRFSOC_SPI_RXFIFO_OP);
+	writel(SIRFSOC_SPI_FIFO_RESET, sspi->base + SIRFSOC_SPI_TXFIFO_OP);
+	writel(SIRFSOC_SPI_FIFO_START, sspi->base + SIRFSOC_SPI_RXFIFO_OP);
+	writel(SIRFSOC_SPI_FIFO_START, sspi->base + SIRFSOC_SPI_TXFIFO_OP);
+
+	return 0;
+}
+
+static const struct dev_pm_ops spi_sirfsoc_pm_ops = {
+	.suspend = spi_sirfsoc_suspend,
+	.resume = spi_sirfsoc_resume,
+};
+#endif
+
+static const struct of_device_id spi_sirfsoc_of_match[] = {
+	{ .compatible = "sirf,prima2-spi", },
+	{}
+};
+MODULE_DEVICE_TABLE(of, sirfsoc_spi_of_match);
+
+static struct platform_driver spi_sirfsoc_driver = {
+	.driver = {
+		.name = DRIVER_NAME,
+		.owner = THIS_MODULE,
+#ifdef CONFIG_PM
+		.pm     = &spi_sirfsoc_pm_ops,
+#endif
+		.of_match_table = spi_sirfsoc_of_match,
+	},
+	.probe = spi_sirfsoc_probe,
+	.remove = __devexit_p(spi_sirfsoc_remove),
+};
+module_platform_driver(spi_sirfsoc_driver);
+
+MODULE_DESCRIPTION("SiRF SoC SPI master driver");
+MODULE_AUTHOR("Zhiwu Song <Zhiwu.Song@csr.com>, "
+		"Barry Song <Baohua.Song@csr.com>");
+MODULE_LICENSE("GPL v2");