ipq8064: copy u-boot spi driver as is

This brings in the banana_cs version of the SPI driver.

BUG=chrome-os-partner:27784
TEST=none

Original-Change-Id: Ie93ec8c962c26fff1f0a235516cd8a4062cab40b
Original-Signed-off-by: Vadim Bendebury <vbendeb@chromium.org>
Original-Reviewed-on: https://chromium-review.googlesource.com/194225
Original-Reviewed-by: David Hendricks <dhendrix@chromium.org>
(cherry picked from commit 3cada6e4ed51a6d4f637aa31a1a836352a99d13d)
Signed-off-by: Marc Jones <marc.jones@se-eng.com>

Change-Id: I0a58a4ddaf9375c22c9b2b249a2baa2c5538ba6c
Reviewed-on: http://review.coreboot.org/7982
Tested-by: build bot (Jenkins)
Reviewed-by: David Hendricks <dhendrix@chromium.org>

1 files changed, 924 insertions, 0 deletions

diff --git a/src/soc/qualcomm/ipq806x/spi.c b/src/soc/qualcomm/ipq806x/spi.c
new file mode 100644
index 0000000000..45ecc0e079
--- /dev/null
+++ b/src/soc/qualcomm/ipq806x/spi.c
@@ -0,0 +1,924 @@
+/*
+ * Copyright (c) 2012 The Linux Foundation. All rights reserved.
+ */
+
+#include <common.h>
+#include <spi.h>
+#include <malloc.h>
+#include <asm/io.h>
+#include <asm/errno.h>
+#include "ipq_spi.h"
+#include <asm/arch-ipq806x/gpio.h>
+#include <asm/arch-ipq806x/iomap.h>
+
+#define SUCCESS		0
+
+#define DUMMY_DATA_VAL		0
+#define TIMEOUT_CNT		100
+#define CS_ASSERT		1
+#define CS_DEASSERT		0
+#define NUM_PORTS		3
+#define NUM_GSBI_PINS		3
+#define TLMM_ARGS		6
+#define NUM_CS			4
+#define GSBI_PIN_IDX		0
+#define FUNC_SEL_IDX		1
+#define GPIO_DIR_IDX		2
+#define PULL_CONF_IDX		3
+#define DRV_STR_IDX		4
+#define GPIO_EN_IDX		5
+
+#define GSBI_IDX_TO_GSBI(idx)   (idx + 5)
+
+/*
+ * TLMM Configuration for SPI NOR
+ * gsbi_pin_conf[bus_num][GPIO_NUM, FUNC_SEL, I/O,
+ *			       PULL UP/DOWN, DRV_STR, GPIO_FUNC]
+ * gsbi_pin_conf[0][x][y] -- GSBI5
+ * gsbi_pin_conf[1][x][y] -- GSBI6
+ * gsbi_pin_conf[2][x][y] -- GSBI7
+*/
+static unsigned int gsbi_pin_conf[NUM_PORTS][NUM_GSBI_PINS][TLMM_ARGS] = {
+	{
+		/* GSBI5 CLK */
+		{
+			GSBI5_SPI_CLK,  FUNC_SEL_1, GPIO_INPUT,
+			GPIO_PULL_DOWN, GPIO_DRV_STR_11MA, GPIO_FUNC_DISABLE
+		},
+		/* GSBI5 MISO */
+		{
+			GSBI5_SPI_MISO, FUNC_SEL_1, GPIO_INPUT,
+			GPIO_PULL_DOWN, GPIO_DRV_STR_10MA, GPIO_FUNC_DISABLE
+		},
+		/* GSBI5 MOSI */
+		{
+			GSBI5_SPI_MOSI, FUNC_SEL_1, GPIO_INPUT,
+			GPIO_PULL_DOWN, GPIO_DRV_STR_10MA, GPIO_FUNC_DISABLE
+		}
+	},
+	{
+		/* GSBI6 CLK */
+		{
+			GSBI6_SPI_CLK,  FUNC_SEL_3, GPIO_INPUT,
+			GPIO_PULL_DOWN, GPIO_DRV_STR_11MA, GPIO_FUNC_DISABLE
+		},
+		/* GSBI6 MISO */
+		{
+			GSBI6_SPI_MISO, FUNC_SEL_3, GPIO_INPUT,
+			GPIO_PULL_DOWN, GPIO_DRV_STR_10MA, GPIO_FUNC_DISABLE
+		},
+		/* GSBI6 MOSI */
+		{
+			GSBI6_SPI_MOSI, FUNC_SEL_3, GPIO_INPUT,
+			GPIO_PULL_DOWN, GPIO_DRV_STR_10MA, GPIO_FUNC_DISABLE
+		}
+	},
+	{
+		/* GSBI7 CLK */
+		{
+			GSBI7_SPI_CLK,  FUNC_SEL_1, GPIO_INPUT,
+			GPIO_PULL_DOWN, GPIO_DRV_STR_11MA, GPIO_FUNC_DISABLE
+		},
+		/* GSBI7 MISO */
+		{
+			GSBI7_SPI_MISO, FUNC_SEL_1, GPIO_INPUT,
+			GPIO_PULL_DOWN, GPIO_DRV_STR_10MA, GPIO_FUNC_DISABLE
+		},
+		/* GSBI7 MOSI */
+		{
+			GSBI7_SPI_MOSI, FUNC_SEL_1, GPIO_INPUT,
+			GPIO_PULL_DOWN, GPIO_DRV_STR_10MA, GPIO_FUNC_DISABLE
+		}
+	}
+};
+
+/*
+ * CS GPIO number array cs_gpio_array[port_num][cs_num]
+ * cs_gpio_array[0][x] -- GSBI5
+ * cs_gpio_array[1][x] -- GSBI6
+ * cs_gpio_array[2][x] -- GSBI7
+ */
+static unsigned int cs_gpio_array[NUM_PORTS][NUM_CS] = {
+	{
+		GSBI5_SPI_CS_0, GSBI5_SPI_CS_1, GSBI5_SPI_CS_2, GSBI5_SPI_CS_3
+	},
+	{
+		GSBI6_SPI_CS_0,              0,              0,              0
+	},
+	{
+		GSBI7_SPI_CS_0,              0,              0,              0
+	}
+};
+
+/*
+ * GSBI HCLK state register bit
+ * hclk_state[0] -- GSBI5
+ * hclk_state[1] -- GSBI6
+ * hclk_state[2] -- GSBI7
+*/
+static unsigned int hclk_state[NUM_PORTS] = {
+	GSBI5_HCLK,
+	GSBI6_HCLK,
+	GSBI7_HCLK
+};
+
+/*
+ * GSBI QUP_APPS_CLK state register bit
+ * qup_apps_clk_state[0] -- GSBI5
+ * qup_apps_clk_state[1] -- GSBI6
+ * qup_apps_clk_state[2] -- GSBI7
+*/
+static unsigned int qup_apps_clk_state[NUM_PORTS] = {
+	GSBI5_QUP_APPS_CLK,
+	GSBI6_QUP_APPS_CLK,
+	GSBI7_QUP_APPS_CLK
+};
+
+
+static int check_bit_state(uint32_t reg_addr, int bit_num, int val, int us_delay)
+{
+	unsigned int count = TIMEOUT_CNT;
+	unsigned int bit_val = ((readl(reg_addr) >> bit_num) & 0x01);
+
+	while (bit_val != val) {
+		count--;
+		if (count == 0)
+			return -ETIMEDOUT;
+		udelay(us_delay);
+		bit_val = ((readl(reg_addr) >> bit_num) & 0x01);
+	}
+
+	return SUCCESS;
+}
+
+/*
+ * Check whether GSBIn_QUP State is valid
+ */
+static int check_qup_state_valid(struct ipq_spi_slave *ds)
+{
+
+	return check_bit_state(ds->regs->qup_state, QUP_STATE_VALID_BIT,
+				QUP_STATE_VALID, 1);
+
+}
+
+/*
+ * Configure GSBIn Core state
+ */
+static int config_spi_state(struct ipq_spi_slave *ds, unsigned int state)
+{
+	uint32_t val;
+	int ret = SUCCESS;
+
+	ret = check_qup_state_valid(ds);
+	if (ret != SUCCESS)
+		return ret;
+
+	switch (state) {
+	case SPI_RUN_STATE:
+		/* Set the state to RUN */
+		val = ((readl(ds->regs->qup_state) & ~QUP_STATE_MASK)
+					| QUP_STATE_RUN_STATE);
+		writel(val, ds->regs->qup_state);
+		ret = check_qup_state_valid(ds);
+		if (ret != SUCCESS)
+			return ret;
+		ds->core_state = SPI_CORE_RUNNING;
+		break;
+	case SPI_RESET_STATE:
+		/* Set the state to RESET */
+		val = ((readl(ds->regs->qup_state) & ~QUP_STATE_MASK)
+					| QUP_STATE_RESET_STATE);
+		writel(val, ds->regs->qup_state);
+		ret = check_qup_state_valid(ds);
+		if (ret != SUCCESS)
+			return ret;
+		ds->core_state = SPI_CORE_RESET;
+		break;
+	default:
+		printf("err: unsupported GSBI SPI state : %d\n", state);
+		ret = -EINVAL;
+		break;
+	}
+
+	return ret;
+}
+
+/*
+ * Set GSBIn SPI Mode
+ */
+static void spi_set_mode(struct ipq_spi_slave *ds, unsigned int mode)
+{
+	unsigned int clk_idle_state;
+	unsigned int input_first_mode;
+	uint32_t val;
+
+	switch (mode) {
+	case GSBI_SPI_MODE_0:
+		clk_idle_state = 0;
+		input_first_mode = SPI_INPUT_FIRST_MODE;
+		break;
+	case GSBI_SPI_MODE_1:
+		clk_idle_state = 0;
+		input_first_mode = 0;
+		break;
+	case GSBI_SPI_MODE_2:
+		clk_idle_state = 1;
+		input_first_mode = SPI_INPUT_FIRST_MODE;
+		break;
+	case GSBI_SPI_MODE_3:
+		clk_idle_state = 1;
+		input_first_mode = 0;
+		break;
+	default:
+		printf("err : unsupported spi mode : %d\n", mode);
+		return;
+	}
+
+	val = readl(ds->regs->spi_config);
+	val |= input_first_mode;
+	writel(val, ds->regs->spi_config);
+
+	val = readl(ds->regs->io_control);
+	if (clk_idle_state)
+		val |= SPI_IO_CONTROL_CLOCK_IDLE_HIGH;
+	else
+		val &= ~SPI_IO_CONTROL_CLOCK_IDLE_HIGH;
+
+	writel(val, ds->regs->io_control);
+}
+
+/*
+ * Check for HCLK state
+ */
+static int check_hclk_state(unsigned int core_num, int enable)
+{
+	if (clk_is_dummy())
+		return 0;
+
+	return check_bit_state(CLK_HALT_CFPB_STATEB_REG,
+		hclk_state[core_num], enable, 5);
+}
+
+/*
+ * Check for QUP APPS CLK state
+ */
+static int check_qup_clk_state(unsigned int core_num, int enable)
+{
+	if (clk_is_dummy())
+		return 0;
+
+	return check_bit_state(CLK_HALT_CFPB_STATEB_REG,
+		qup_apps_clk_state[core_num], enable, 5);
+}
+
+/*
+ * Function to assert and De-assert chip select
+ */
+static void CS_change(int port_num, int cs_num, int enable)
+{
+	unsigned int cs_gpio = cs_gpio_array[port_num][cs_num];
+	uint32_t addr = GPIO_IN_OUT_ADDR(cs_gpio);
+	uint32_t val = readl(addr);
+
+	val &= (~(1 << GPIO_OUT));
+	if (!enable)
+		val |= (1 << GPIO_OUT);
+	writel(val, addr);
+}
+
+/*
+ * GSBIn TLMM configuration
+ */
+static void gsbi_pin_config(unsigned int port_num, int cs_num)
+{
+	unsigned int gpio;
+	unsigned int i;
+	/* Hold the GSBIn (core_num) core in reset */
+	clrsetbits_le32(GSBIn_RESET_REG(GSBI_IDX_TO_GSBI(port_num)),
+			GSBI1_RESET_MSK, GSBI1_RESET);
+
+	/*
+	 * Configure SPI_CLK, SPI_MISO and SPI_MOSI
+	 */
+	for (i = 0; i < NUM_GSBI_PINS; i++) {
+		unsigned int func_sel;
+		unsigned int io_config;
+		unsigned int pull_config;
+		unsigned int drv_strength;
+		unsigned int gpio_en;
+		unsigned int *ptr;
+
+		ptr = gsbi_pin_conf[port_num][i];
+		gpio		= *(ptr + GSBI_PIN_IDX);
+		func_sel	= *(ptr + FUNC_SEL_IDX);
+		io_config	= *(ptr + GPIO_DIR_IDX);
+		pull_config	= *(ptr + PULL_CONF_IDX);
+		drv_strength	= *(ptr + DRV_STR_IDX);
+		gpio_en	= *(ptr + GPIO_EN_IDX);
+
+		gpio_tlmm_config(gpio, func_sel, io_config,
+				 pull_config, drv_strength, gpio_en);
+	}
+
+	gpio = cs_gpio_array[port_num][cs_num];
+	/* configure CS */
+	gpio_tlmm_config(gpio, FUNC_SEL_GPIO, GPIO_OUTPUT, GPIO_PULL_UP,
+				GPIO_DRV_STR_10MA, GPIO_FUNC_ENABLE);
+	CS_change(port_num, cs_num, CS_DEASSERT);
+}
+
+/*
+ * Clock configuration for GSBIn Core
+ */
+static int gsbi_clock_init(struct ipq_spi_slave *ds)
+{
+	int ret;
+
+	/* Hold the GSBIn (core_num) core in reset */
+	clrsetbits_le32(GSBIn_RESET_REG(GSBI_IDX_TO_GSBI(ds->slave.bus)),
+			GSBI1_RESET_MSK, GSBI1_RESET);
+
+	/* Disable GSBIn (core_num) QUP core clock branch */
+	clrsetbits_le32(ds->regs->qup_ns_reg, QUP_CLK_BRANCH_ENA_MSK,
+					QUP_CLK_BRANCH_DIS);
+
+	ret = check_qup_clk_state(ds->slave.bus, 1);
+	if (ret) {
+		printf("QUP Clock Halt For GSBI%d failed!\n", ds->slave.bus);
+		return ret;
+	}
+
+	/* Disable M/N:D counter and hold M/N:D counter in reset */
+	clrsetbits_le32(ds->regs->qup_ns_reg, (MNCNTR_MSK | MNCNTR_RST_MSK),
+					(MNCNTR_RST_ENA | MNCNTR_DIS));
+
+	/* Disable GSBIn (core_num) QUP core clock root */
+	clrsetbits_le32(ds->regs->qup_ns_reg, CLK_ROOT_ENA_MSK, CLK_ROOT_DIS);
+
+	clrsetbits_le32(ds->regs->qup_ns_reg, GSBIn_PLL_SRC_MSK,
+					GSBIn_PLL_SRC_PLL8);
+	clrsetbits_le32(ds->regs->qup_ns_reg, GSBIn_PRE_DIV_SEL_MSK,
+						(0 << GSBI_PRE_DIV_SEL_SHFT));
+
+	/* Program M/N:D values for GSBIn_QUP_APPS_CLK @50MHz */
+	clrsetbits_le32(ds->regs->qup_md_reg, GSBIn_M_VAL_MSK,
+						(0x01 << GSBI_M_VAL_SHFT));
+	clrsetbits_le32(ds->regs->qup_md_reg, GSBIn_D_VAL_MSK,
+						(0xF7 << GSBI_D_VAL_SHFT));
+	clrsetbits_le32(ds->regs->qup_ns_reg, GSBIn_N_VAL_MSK,
+						(0xF8 << GSBI_N_VAL_SHFT));
+
+	/* Set MNCNTR_MODE = 0: Bypass mode */
+	clrsetbits_le32(ds->regs->qup_ns_reg, MNCNTR_MODE_MSK,
+					MNCNTR_MODE_DUAL_EDGE);
+
+	/* De-assert the M/N:D counter reset */
+	clrsetbits_le32(ds->regs->qup_ns_reg, MNCNTR_RST_MSK, MNCNTR_RST_DIS);
+	clrsetbits_le32(ds->regs->qup_ns_reg, MNCNTR_MSK, MNCNTR_EN);
+
+	/*
+	 * Enable the GSBIn (core_num) QUP core clock root.
+	 * Keep MND counter disabled
+	 */
+	clrsetbits_le32(ds->regs->qup_ns_reg, CLK_ROOT_ENA_MSK, CLK_ROOT_ENA);
+
+	/* Enable GSBIn (core_num) QUP core clock branch */
+	clrsetbits_le32(ds->regs->qup_ns_reg, QUP_CLK_BRANCH_ENA_MSK,
+						QUP_CLK_BRANCH_ENA);
+
+	ret = check_qup_clk_state(ds->slave.bus, 0);
+	if (ret) {
+		printf("QUP Clock Enable For GSBI%d"
+				" failed!\n", ds->slave.bus);
+		return ret;
+	}
+
+	/* Enable GSBIn (core_num) core clock branch */
+	clrsetbits_le32(GSBIn_HCLK_CTL_REG(GSBI_IDX_TO_GSBI(ds->slave.bus)),
+			GSBI_CLK_BRANCH_ENA_MSK, GSBI_CLK_BRANCH_ENA);
+
+	ret = check_hclk_state(ds->slave.bus, 0);
+	if (ret) {
+		printf("HCLK Enable For GSBI%d failed!\n", ds->slave.bus);
+		return ret;
+	}
+
+	/* Release GSBIn (core_num) core from reset */
+	clrsetbits_le32(GSBIn_RESET_REG(GSBI_IDX_TO_GSBI(ds->slave.bus)),
+						GSBI1_RESET_MSK, 0);
+	udelay(50);
+
+	return SUCCESS;
+}
+
+/*
+ * Reset entire QUP and all mini cores
+ */
+static void spi_reset(struct ipq_spi_slave *ds)
+{
+	writel(0x1, ds->regs->qup_sw_reset);
+	udelay(5);
+}
+
+void spi_init()
+{
+	/* do nothing */
+
+}
+
+struct spi_slave *spi_setup_slave(unsigned int bus, unsigned int cs,
+				unsigned int max_hz, unsigned int mode)
+{
+	struct ipq_spi_slave *ds;
+
+	ds = malloc(sizeof(struct ipq_spi_slave));
+	if (!ds) {
+		printf("SPI error: malloc of SPI structure failed\n");
+		return NULL;
+	}
+
+	/*
+	 * IPQ GSBI (Generic Serial Bus Interface) supports SPI Flash
+	 * on different GSBI5, GSBI6 and GSBI7
+	 * with different number of chip selects (CS, channels):
+	*/
+	if ((bus < GSBI5_SPI) || (bus > GSBI7_SPI)
+		|| ((bus == GSBI5_SPI) && (cs > 3))
+		|| ((bus == GSBI6_SPI) && (cs > 0))
+		|| ((bus == GSBI7_SPI) && (cs > 0))) {
+		printf("SPI error: unsupported bus %d "
+			"(Supported busses 0,1 and 2) or chipselect\n", bus);
+		goto err;
+	}
+	ds->slave.bus	= bus;
+	ds->slave.cs	= cs;
+
+	ds->regs	= &spi_reg[bus];
+
+	/* TODO For different clock frequency */
+	if (max_hz > MSM_GSBI_MAX_FREQ) {
+		printf("SPI error: unsupported frequency %d Hz "
+			"Max frequency is %d Hz\n", max_hz, MSM_GSBI_MAX_FREQ);
+		goto err;
+	}
+	ds->freq = max_hz;
+
+	if (mode > GSBI_SPI_MODE_3) {
+		printf("SPI error: unsupported SPI mode %d\n", mode);
+		goto err;
+	}
+	ds->mode = mode;
+
+	return &ds->slave;
+
+err:
+	free(ds);
+	return NULL;
+}
+
+void spi_free_slave(struct spi_slave *slave)
+{
+	struct ipq_spi_slave *ds = to_ipq_spi(slave);
+
+	if (ds != NULL)
+		free(ds);
+}
+
+/*
+ * GSBIn SPI Hardware Initialisation
+ */
+static int spi_hw_init(struct ipq_spi_slave *ds)
+{
+	int ret;
+
+	ds->initialized = 0;
+
+	/* GSBI module configuration */
+	spi_reset(ds);
+
+	/* Set the GSBIn QUP state */
+	ret = config_spi_state(ds, SPI_RESET_STATE);
+	if (ret)
+		return ret;
+
+	/* Configure GSBI_CTRL register to set protocol_mode to SPI:011 */
+	clrsetbits_le32(ds->regs->gsbi_ctrl, PROTOCOL_CODE_MSK,
+					PROTOCOL_CODE_SPI);
+
+	/*
+	 * Configure Mini core to SPI core with Input Output enabled,
+	 * SPI master, N = 8 bits
+	 */
+	clrsetbits_le32(ds->regs->qup_config, (QUP_CONFIG_MINI_CORE_MSK |
+					       SPI_QUP_CONF_INPUT_MSK |
+					       SPI_QUP_CONF_OUTPUT_MSK |
+					       SPI_BIT_WORD_MSK),
+					      (QUP_CONFIG_MINI_CORE_SPI |
+					       SPI_QUP_CONF_INPUT_ENA |
+					       SPI_QUP_CONF_OUTPUT_ENA |
+					       SPI_8_BIT_WORD));
+
+	/*
+	 * Configure Input first SPI protocol,
+	 * SPI master mode and no loopback
+	 */
+	clrsetbits_le32(ds->regs->spi_config, (LOOP_BACK_MSK |
+					       SLAVE_OPERATION_MSK),
+					      (NO_LOOP_BACK |
+					       SLAVE_OPERATION));
+
+	/*
+	 * Configure SPI IO Control Register
+	 * CLK_ALWAYS_ON = 0
+	 * MX_CS_MODE = 0
+	 * NO_TRI_STATE = 1
+	 */
+	writel((CLK_ALWAYS_ON | MX_CS_MODE | NO_TRI_STATE),
+				ds->regs->io_control);
+
+	/*
+	 * Configure SPI IO Modes.
+	 * OUTPUT_BIT_SHIFT_EN = 1
+	 * INPUT_MODE = Block Mode
+	 * OUTPUT MODE = Block Mode
+	 */
+	clrsetbits_le32(ds->regs->qup_io_modes, (OUTPUT_BIT_SHIFT_MSK |
+						 INPUT_BLOCK_MODE_MSK |
+						 OUTPUT_BLOCK_MODE_MSK),
+						(OUTPUT_BIT_SHIFT_EN |
+						 INPUT_BLOCK_MODE |
+						 OUTPUT_BLOCK_MODE));
+
+	spi_set_mode(ds, ds->mode);
+
+	/* Disable Error mask */
+	writel(0, ds->regs->error_flags_en);
+	writel(0, ds->regs->qup_error_flags_en);
+
+	ds->initialized = 1;
+
+	return SUCCESS;
+}
+
+int spi_claim_bus(struct spi_slave *slave)
+{
+	struct ipq_spi_slave *ds = to_ipq_spi(slave);
+	unsigned int ret;
+
+	/* GPIO Configuration for SPI port */
+	gsbi_pin_config(ds->slave.bus, ds->slave.cs);
+
+	/* Clock configuration */
+	ret = gsbi_clock_init(ds);
+	if (ret)
+		return ret;
+
+	ret = spi_hw_init(ds);
+	if (ret)
+		return -EIO;
+
+	return SUCCESS;
+}
+
+void spi_release_bus(struct spi_slave *slave)
+{
+	struct ipq_spi_slave *ds = to_ipq_spi(slave);
+
+	/* Reset the SPI hardware */
+	spi_reset(ds);
+	ds->initialized = 0;
+}
+
+/* Drain input fifo
+ * If input fifo is not empty drain the input FIFO. When the
+ * input fifo is drained make sure that the output fifo is also
+ * empty and break when the input fifo is completely drained.
+ */
+static void flush_fifos(struct ipq_spi_slave *ds)
+{
+	unsigned int fifo_data;
+
+	while (1) {
+		if (readl(ds->regs->qup_operational) &
+			QUP_DATA_AVAILABLE_FOR_READ) {
+			fifo_data = readl(ds->regs->qup_input_fifo);
+		} else {
+			if (!(readl(ds->regs->qup_operational) &
+				QUP_OUTPUT_FIFO_NOT_EMPTY)) {
+				if (!(readl(ds->regs->qup_operational) &
+					QUP_DATA_AVAILABLE_FOR_READ))
+					break;
+			}
+		}
+	}
+
+	(void)fifo_data;
+}
+
+/*
+ * Function to write data to OUTPUT FIFO
+ */
+static void spi_write_byte(struct ipq_spi_slave *ds, unsigned char data)
+{
+	/* Wait for space in the FIFO */
+	while ((readl(ds->regs->qup_operational) & QUP_OUTPUT_FIFO_FULL))
+		udelay(1);
+
+	/* Write the byte of data */
+	writel(data, ds->regs->qup_output_fifo);
+}
+
+/*
+ * Function to read data from Input FIFO
+ */
+static unsigned char spi_read_byte(struct ipq_spi_slave *ds)
+{
+	/* Wait for Data in FIFO */
+	while (!(readl(ds->regs->qup_operational) &
+			QUP_DATA_AVAILABLE_FOR_READ)) {
+		udelay(1);
+	}
+
+	/* Read a byte of data */
+	return readl(ds->regs->qup_input_fifo) & 0xff;
+}
+
+/*
+ * Function to check wheather Input or Output FIFO
+ * has data to be serviced
+ */
+static int check_fifo_status(uint32_t reg_addr)
+{
+	unsigned int count = TIMEOUT_CNT;
+	unsigned int status_flag;
+	unsigned int val;
+
+	do {
+		val = readl(reg_addr);
+		count--;
+		if (count == 0)
+			return -ETIMEDOUT;
+		status_flag = ((val & OUTPUT_SERVICE_FLAG) | (val & INPUT_SERVICE_FLAG));
+	} while (!status_flag);
+
+	return SUCCESS;
+}
+
+/*
+ * Function to read bytes number of data from the Input FIFO
+ */
+static int gsbi_spi_read(struct ipq_spi_slave *ds, u8 *data_buffer,
+				unsigned int bytes, unsigned long flags)
+{
+	uint32_t val;
+	unsigned int i;
+	unsigned int read_bytes = bytes;
+	unsigned int fifo_count;
+	int ret = SUCCESS;
+	int state_config;
+
+	if (flags & SPI_XFER_BEGIN) {
+		/* Assert chip select */
+		CS_change(ds->slave.bus, ds->slave.cs, CS_ASSERT);
+	}
+
+	/* Configure no of bytes to read */
+	state_config = config_spi_state(ds, SPI_RESET_STATE);
+	if (state_config)
+		return state_config;
+
+	writel(bytes, ds->regs->qup_mx_output_count);
+	writel(bytes, ds->regs->qup_mx_input_count);
+
+	state_config = config_spi_state(ds, SPI_RUN_STATE);
+	if (state_config)
+		return state_config;
+
+	while (read_bytes) {
+
+		ret = check_fifo_status(ds->regs->qup_operational);
+		if (ret != SUCCESS)
+			goto out;
+
+		val = readl(ds->regs->qup_operational);
+		if (val & INPUT_SERVICE_FLAG) {
+			/*
+			 * acknowledge to hw that software will
+			 * read input data
+			 */
+			val &= INPUT_SERVICE_FLAG;
+			writel(val, ds->regs->qup_operational);
+
+			fifo_count = ((read_bytes > SPI_INPUT_BLOCK_SIZE) ?
+					SPI_INPUT_BLOCK_SIZE : read_bytes);
+
+			for (i = 0; i < fifo_count; i++) {
+				*data_buffer = spi_read_byte(ds);
+				data_buffer++;
+				read_bytes--;
+			}
+		}
+
+		if (val & OUTPUT_SERVICE_FLAG) {
+			/*
+			 * acknowledge to hw that software will
+			 * write output data
+			 */
+			val &= OUTPUT_SERVICE_FLAG;
+			writel(val, ds->regs->qup_operational);
+
+			fifo_count = ((read_bytes > SPI_OUTPUT_BLOCK_SIZE) ?
+					SPI_OUTPUT_BLOCK_SIZE : read_bytes);
+
+			for (i = 0; i < fifo_count; i++) {
+				/*
+				 * Write dummy data byte for the device
+				 * to shift in actual data. Most of the SPI devices
+				 * accepts dummy data value as 0. In case of any
+				 * other value change DUMMY_DATA_VAL.
+				 */
+				spi_write_byte(ds, DUMMY_DATA_VAL);
+			}
+		}
+	}
+
+	if (flags & SPI_XFER_END) {
+		flush_fifos(ds);
+		goto out;
+	}
+
+	return ret;
+
+out:
+	/* Deassert CS */
+	CS_change(ds->slave.bus, ds->slave.cs, CS_DEASSERT);
+
+	/*
+	 * Put the SPI Core back in the Reset State
+	 * to end the transfer
+	 */
+	(void)config_spi_state(ds, SPI_RESET_STATE);
+
+	return ret;
+
+}
+
+/*
+ * Function to write data to the Output FIFO
+ */
+static int gsbi_spi_write(struct ipq_spi_slave *ds, const u8 *cmd_buffer,
+				unsigned int bytes, unsigned long flags)
+{
+	uint32_t val;
+	unsigned int i;
+	unsigned int write_len = bytes;
+	unsigned int read_len = bytes;
+	unsigned int fifo_count;
+	int ret = SUCCESS;
+	int state_config;
+
+	if (flags & SPI_XFER_BEGIN) {
+		/* Select the chip select */
+		CS_change(ds->slave.bus, ds->slave.cs, CS_ASSERT);
+	}
+
+	state_config = config_spi_state(ds, SPI_RESET_STATE);
+	if (state_config)
+		return state_config;
+
+	/* No of bytes to be written in Output FIFO */
+	writel(bytes, ds->regs->qup_mx_output_count);
+	writel(bytes, ds->regs->qup_mx_input_count);
+	state_config = config_spi_state(ds, SPI_RUN_STATE);
+	if (state_config)
+		return state_config;
+
+	/*
+	 * read_len considered to ensure that we read the dummy data for the
+	 * write we performed. This is needed to ensure with WR-RD transaction
+	 * to get the actual data on the subsequent read cycle that happens
+	 */
+	while (write_len || read_len) {
+
+		ret = check_fifo_status(ds->regs->qup_operational);
+		if (ret != SUCCESS)
+			goto out;
+
+		val = readl(ds->regs->qup_operational);
+		if (val & OUTPUT_SERVICE_FLAG) {
+			/*
+			 * acknowledge to hw that software will write
+			 * expected output data
+			 */
+			val &= OUTPUT_SERVICE_FLAG;
+			writel(val, ds->regs->qup_operational);
+
+			if (write_len > SPI_OUTPUT_BLOCK_SIZE)
+                                fifo_count = SPI_OUTPUT_BLOCK_SIZE;
+                        else
+                                fifo_count = write_len;
+
+			for (i = 0; i < fifo_count; i++) {
+				/* Write actual data to output FIFO */
+				spi_write_byte(ds, *cmd_buffer);
+				cmd_buffer++;
+				write_len--;
+			}
+		}
+		if (val & INPUT_SERVICE_FLAG) {
+			/*
+			 * acknowledge to hw that software
+			 * will read input data
+			 */
+			val &= INPUT_SERVICE_FLAG;
+			writel(val, ds->regs->qup_operational);
+
+			if (read_len > SPI_INPUT_BLOCK_SIZE)
+				fifo_count = SPI_INPUT_BLOCK_SIZE;
+			else
+				fifo_count = read_len;
+
+			for (i = 0; i < fifo_count; i++) {
+				/* Read dummy data for the data written */
+				(void)spi_read_byte(ds);
+
+				/* Decrement the write count after reading the dummy data
+				 * from the device. This is to make sure we read dummy data
+				 * before we write the data to fifo
+				 */
+				read_len--;
+			}
+		}
+	}
+
+	if (flags & SPI_XFER_END) {
+		flush_fifos(ds);
+		goto out;
+	}
+
+	return ret;
+
+out:
+	/* Deassert CS */
+	CS_change(ds->slave.bus, ds->slave.cs, CS_DEASSERT);
+
+	/*
+	 * Put the SPI Core back in the Reset State
+	 * to end the transfer
+	 */
+	(void)config_spi_state(ds, SPI_RESET_STATE);
+
+	return ret;
+}
+
+/*
+ * This function is invoked with either tx_buf or rx_buf.
+ * Calling this function with both null does a chip select change.
+ */
+int spi_xfer(struct spi_slave *slave, unsigned int bitlen,
+		const void *dout, void *din, unsigned long flags)
+{
+	struct ipq_spi_slave *ds = to_ipq_spi(slave);
+	unsigned int len;
+	const u8 *txp = dout;
+	u8 *rxp = din;
+	int ret;
+
+	if (bitlen & 0x07) {
+		printf("err : Invalid bit length");
+		return -EINVAL;
+	}
+
+	len = bitlen >> 3;
+
+	if (dout != NULL) {
+		ret = gsbi_spi_write(ds, txp, len, flags);
+		if (ret != SUCCESS)
+			return ret;
+	}
+
+	if (din != NULL)
+		return gsbi_spi_read(ds, rxp, len, flags);
+
+	if ((din == NULL) && (dout == NULL))
+		/* To handle only when chip select change is needed */
+		ret = gsbi_spi_write(ds, NULL, 0, flags);
+
+	return ret;
+}
+
+int spi_cs_is_valid(unsigned int bus, unsigned int cs)
+{
+	return 1;
+}
+
+void spi_cs_activate(struct spi_slave *slave)
+{
+
+}
+
+void spi_cs_deactivate(struct spi_slave *slave)
+{
+
+}