spi: reorganize drivers

Sort the SPI makefile and enforce the naming convention spi_*.c for
spi drivers.

This change also rolls the contents of atmel_spi.h into the .c file
since there is only one user of that particular include file.

v2: - Use 'spi-' prefix instead of 'spi_' to match what seems to be
      be the predominant pattern for subsystem prefixes.
    - Clean up filenames in Kconfig and header comment blocks

Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
Acked-by: Wolfram Sang <w.sang@pengutronix.de>
Acked-by: Linus Walleij <linus.walleij@linaro.org>

1 files changed, 936 insertions, 0 deletions

diff --git a/drivers/spi/spi-dw.c b/drivers/spi/spi-dw.c
new file mode 100644
index 000000000000..ece5f69deaaf
--- /dev/null
+++ b/drivers/spi/spi-dw.c
@@ -0,0 +1,936 @@
+/*
+ * Designware SPI core controller driver (refer pxa2xx_spi.c)
+ *
+ * Copyright (c) 2009, Intel Corporation.
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
+ * more details.
+ *
+ * You should have received a copy of the GNU General Public License along with
+ * this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin St - Fifth Floor, Boston, MA 02110-1301 USA.
+ */
+
+#include <linux/dma-mapping.h>
+#include <linux/interrupt.h>
+#include <linux/highmem.h>
+#include <linux/delay.h>
+#include <linux/slab.h>
+#include <linux/spi/spi.h>
+
+#include "spi-dw.h"
+
+#ifdef CONFIG_DEBUG_FS
+#include <linux/debugfs.h>
+#endif
+
+#define START_STATE	((void *)0)
+#define RUNNING_STATE	((void *)1)
+#define DONE_STATE	((void *)2)
+#define ERROR_STATE	((void *)-1)
+
+#define QUEUE_RUNNING	0
+#define QUEUE_STOPPED	1
+
+#define MRST_SPI_DEASSERT	0
+#define MRST_SPI_ASSERT		1
+
+/* Slave spi_dev related */
+struct chip_data {
+	u16 cr0;
+	u8 cs;			/* chip select pin */
+	u8 n_bytes;		/* current is a 1/2/4 byte op */
+	u8 tmode;		/* TR/TO/RO/EEPROM */
+	u8 type;		/* SPI/SSP/MicroWire */
+
+	u8 poll_mode;		/* 1 means use poll mode */
+
+	u32 dma_width;
+	u32 rx_threshold;
+	u32 tx_threshold;
+	u8 enable_dma;
+	u8 bits_per_word;
+	u16 clk_div;		/* baud rate divider */
+	u32 speed_hz;		/* baud rate */
+	void (*cs_control)(u32 command);
+};
+
+#ifdef CONFIG_DEBUG_FS
+static int spi_show_regs_open(struct inode *inode, struct file *file)
+{
+	file->private_data = inode->i_private;
+	return 0;
+}
+
+#define SPI_REGS_BUFSIZE	1024
+static ssize_t  spi_show_regs(struct file *file, char __user *user_buf,
+				size_t count, loff_t *ppos)
+{
+	struct dw_spi *dws;
+	char *buf;
+	u32 len = 0;
+	ssize_t ret;
+
+	dws = file->private_data;
+
+	buf = kzalloc(SPI_REGS_BUFSIZE, GFP_KERNEL);
+	if (!buf)
+		return 0;
+
+	len += snprintf(buf + len, SPI_REGS_BUFSIZE - len,
+			"MRST SPI0 registers:\n");
+	len += snprintf(buf + len, SPI_REGS_BUFSIZE - len,
+			"=================================\n");
+	len += snprintf(buf + len, SPI_REGS_BUFSIZE - len,
+			"CTRL0: \t\t0x%08x\n", dw_readl(dws, ctrl0));
+	len += snprintf(buf + len, SPI_REGS_BUFSIZE - len,
+			"CTRL1: \t\t0x%08x\n", dw_readl(dws, ctrl1));
+	len += snprintf(buf + len, SPI_REGS_BUFSIZE - len,
+			"SSIENR: \t0x%08x\n", dw_readl(dws, ssienr));
+	len += snprintf(buf + len, SPI_REGS_BUFSIZE - len,
+			"SER: \t\t0x%08x\n", dw_readl(dws, ser));
+	len += snprintf(buf + len, SPI_REGS_BUFSIZE - len,
+			"BAUDR: \t\t0x%08x\n", dw_readl(dws, baudr));
+	len += snprintf(buf + len, SPI_REGS_BUFSIZE - len,
+			"TXFTLR: \t0x%08x\n", dw_readl(dws, txfltr));
+	len += snprintf(buf + len, SPI_REGS_BUFSIZE - len,
+			"RXFTLR: \t0x%08x\n", dw_readl(dws, rxfltr));
+	len += snprintf(buf + len, SPI_REGS_BUFSIZE - len,
+			"TXFLR: \t\t0x%08x\n", dw_readl(dws, txflr));
+	len += snprintf(buf + len, SPI_REGS_BUFSIZE - len,
+			"RXFLR: \t\t0x%08x\n", dw_readl(dws, rxflr));
+	len += snprintf(buf + len, SPI_REGS_BUFSIZE - len,
+			"SR: \t\t0x%08x\n", dw_readl(dws, sr));
+	len += snprintf(buf + len, SPI_REGS_BUFSIZE - len,
+			"IMR: \t\t0x%08x\n", dw_readl(dws, imr));
+	len += snprintf(buf + len, SPI_REGS_BUFSIZE - len,
+			"ISR: \t\t0x%08x\n", dw_readl(dws, isr));
+	len += snprintf(buf + len, SPI_REGS_BUFSIZE - len,
+			"DMACR: \t\t0x%08x\n", dw_readl(dws, dmacr));
+	len += snprintf(buf + len, SPI_REGS_BUFSIZE - len,
+			"DMATDLR: \t0x%08x\n", dw_readl(dws, dmatdlr));
+	len += snprintf(buf + len, SPI_REGS_BUFSIZE - len,
+			"DMARDLR: \t0x%08x\n", dw_readl(dws, dmardlr));
+	len += snprintf(buf + len, SPI_REGS_BUFSIZE - len,
+			"=================================\n");
+
+	ret =  simple_read_from_buffer(user_buf, count, ppos, buf, len);
+	kfree(buf);
+	return ret;
+}
+
+static const struct file_operations mrst_spi_regs_ops = {
+	.owner		= THIS_MODULE,
+	.open		= spi_show_regs_open,
+	.read		= spi_show_regs,
+	.llseek		= default_llseek,
+};
+
+static int mrst_spi_debugfs_init(struct dw_spi *dws)
+{
+	dws->debugfs = debugfs_create_dir("mrst_spi", NULL);
+	if (!dws->debugfs)
+		return -ENOMEM;
+
+	debugfs_create_file("registers", S_IFREG | S_IRUGO,
+		dws->debugfs, (void *)dws, &mrst_spi_regs_ops);
+	return 0;
+}
+
+static void mrst_spi_debugfs_remove(struct dw_spi *dws)
+{
+	if (dws->debugfs)
+		debugfs_remove_recursive(dws->debugfs);
+}
+
+#else
+static inline int mrst_spi_debugfs_init(struct dw_spi *dws)
+{
+	return 0;
+}
+
+static inline void mrst_spi_debugfs_remove(struct dw_spi *dws)
+{
+}
+#endif /* CONFIG_DEBUG_FS */
+
+/* Return the max entries we can fill into tx fifo */
+static inline u32 tx_max(struct dw_spi *dws)
+{
+	u32 tx_left, tx_room, rxtx_gap;
+
+	tx_left = (dws->tx_end - dws->tx) / dws->n_bytes;
+	tx_room = dws->fifo_len - dw_readw(dws, txflr);
+
+	/*
+	 * Another concern is about the tx/rx mismatch, we
+	 * though to use (dws->fifo_len - rxflr - txflr) as
+	 * one maximum value for tx, but it doesn't cover the
+	 * data which is out of tx/rx fifo and inside the
+	 * shift registers. So a control from sw point of
+	 * view is taken.
+	 */
+	rxtx_gap =  ((dws->rx_end - dws->rx) - (dws->tx_end - dws->tx))
+			/ dws->n_bytes;
+
+	return min3(tx_left, tx_room, (u32) (dws->fifo_len - rxtx_gap));
+}
+
+/* Return the max entries we should read out of rx fifo */
+static inline u32 rx_max(struct dw_spi *dws)
+{
+	u32 rx_left = (dws->rx_end - dws->rx) / dws->n_bytes;
+
+	return min(rx_left, (u32)dw_readw(dws, rxflr));
+}
+
+static void dw_writer(struct dw_spi *dws)
+{
+	u32 max = tx_max(dws);
+	u16 txw = 0;
+
+	while (max--) {
+		/* Set the tx word if the transfer's original "tx" is not null */
+		if (dws->tx_end - dws->len) {
+			if (dws->n_bytes == 1)
+				txw = *(u8 *)(dws->tx);
+			else
+				txw = *(u16 *)(dws->tx);
+		}
+		dw_writew(dws, dr, txw);
+		dws->tx += dws->n_bytes;
+	}
+}
+
+static void dw_reader(struct dw_spi *dws)
+{
+	u32 max = rx_max(dws);
+	u16 rxw;
+
+	while (max--) {
+		rxw = dw_readw(dws, dr);
+		/* Care rx only if the transfer's original "rx" is not null */
+		if (dws->rx_end - dws->len) {
+			if (dws->n_bytes == 1)
+				*(u8 *)(dws->rx) = rxw;
+			else
+				*(u16 *)(dws->rx) = rxw;
+		}
+		dws->rx += dws->n_bytes;
+	}
+}
+
+static void *next_transfer(struct dw_spi *dws)
+{
+	struct spi_message *msg = dws->cur_msg;
+	struct spi_transfer *trans = dws->cur_transfer;
+
+	/* Move to next transfer */
+	if (trans->transfer_list.next != &msg->transfers) {
+		dws->cur_transfer =
+			list_entry(trans->transfer_list.next,
+					struct spi_transfer,
+					transfer_list);
+		return RUNNING_STATE;
+	} else
+		return DONE_STATE;
+}
+
+/*
+ * Note: first step is the protocol driver prepares
+ * a dma-capable memory, and this func just need translate
+ * the virt addr to physical
+ */
+static int map_dma_buffers(struct dw_spi *dws)
+{
+	if (!dws->cur_msg->is_dma_mapped
+		|| !dws->dma_inited
+		|| !dws->cur_chip->enable_dma
+		|| !dws->dma_ops)
+		return 0;
+
+	if (dws->cur_transfer->tx_dma)
+		dws->tx_dma = dws->cur_transfer->tx_dma;
+
+	if (dws->cur_transfer->rx_dma)
+		dws->rx_dma = dws->cur_transfer->rx_dma;
+
+	return 1;
+}
+
+/* Caller already set message->status; dma and pio irqs are blocked */
+static void giveback(struct dw_spi *dws)
+{
+	struct spi_transfer *last_transfer;
+	unsigned long flags;
+	struct spi_message *msg;
+
+	spin_lock_irqsave(&dws->lock, flags);
+	msg = dws->cur_msg;
+	dws->cur_msg = NULL;
+	dws->cur_transfer = NULL;
+	dws->prev_chip = dws->cur_chip;
+	dws->cur_chip = NULL;
+	dws->dma_mapped = 0;
+	queue_work(dws->workqueue, &dws->pump_messages);
+	spin_unlock_irqrestore(&dws->lock, flags);
+
+	last_transfer = list_entry(msg->transfers.prev,
+					struct spi_transfer,
+					transfer_list);
+
+	if (!last_transfer->cs_change && dws->cs_control)
+		dws->cs_control(MRST_SPI_DEASSERT);
+
+	msg->state = NULL;
+	if (msg->complete)
+		msg->complete(msg->context);
+}
+
+static void int_error_stop(struct dw_spi *dws, const char *msg)
+{
+	/* Stop the hw */
+	spi_enable_chip(dws, 0);
+
+	dev_err(&dws->master->dev, "%s\n", msg);
+	dws->cur_msg->state = ERROR_STATE;
+	tasklet_schedule(&dws->pump_transfers);
+}
+
+void dw_spi_xfer_done(struct dw_spi *dws)
+{
+	/* Update total byte transferred return count actual bytes read */
+	dws->cur_msg->actual_length += dws->len;
+
+	/* Move to next transfer */
+	dws->cur_msg->state = next_transfer(dws);
+
+	/* Handle end of message */
+	if (dws->cur_msg->state == DONE_STATE) {
+		dws->cur_msg->status = 0;
+		giveback(dws);
+	} else
+		tasklet_schedule(&dws->pump_transfers);
+}
+EXPORT_SYMBOL_GPL(dw_spi_xfer_done);
+
+static irqreturn_t interrupt_transfer(struct dw_spi *dws)
+{
+	u16 irq_status = dw_readw(dws, isr);
+
+	/* Error handling */
+	if (irq_status & (SPI_INT_TXOI | SPI_INT_RXOI | SPI_INT_RXUI)) {
+		dw_readw(dws, txoicr);
+		dw_readw(dws, rxoicr);
+		dw_readw(dws, rxuicr);
+		int_error_stop(dws, "interrupt_transfer: fifo overrun/underrun");
+		return IRQ_HANDLED;
+	}
+
+	dw_reader(dws);
+	if (dws->rx_end == dws->rx) {
+		spi_mask_intr(dws, SPI_INT_TXEI);
+		dw_spi_xfer_done(dws);
+		return IRQ_HANDLED;
+	}
+	if (irq_status & SPI_INT_TXEI) {
+		spi_mask_intr(dws, SPI_INT_TXEI);
+		dw_writer(dws);
+		/* Enable TX irq always, it will be disabled when RX finished */
+		spi_umask_intr(dws, SPI_INT_TXEI);
+	}
+
+	return IRQ_HANDLED;
+}
+
+static irqreturn_t dw_spi_irq(int irq, void *dev_id)
+{
+	struct dw_spi *dws = dev_id;
+	u16 irq_status = dw_readw(dws, isr) & 0x3f;
+
+	if (!irq_status)
+		return IRQ_NONE;
+
+	if (!dws->cur_msg) {
+		spi_mask_intr(dws, SPI_INT_TXEI);
+		return IRQ_HANDLED;
+	}
+
+	return dws->transfer_handler(dws);
+}
+
+/* Must be called inside pump_transfers() */
+static void poll_transfer(struct dw_spi *dws)
+{
+	do {
+		dw_writer(dws);
+		dw_reader(dws);
+		cpu_relax();
+	} while (dws->rx_end > dws->rx);
+
+	dw_spi_xfer_done(dws);
+}
+
+static void pump_transfers(unsigned long data)
+{
+	struct dw_spi *dws = (struct dw_spi *)data;
+	struct spi_message *message = NULL;
+	struct spi_transfer *transfer = NULL;
+	struct spi_transfer *previous = NULL;
+	struct spi_device *spi = NULL;
+	struct chip_data *chip = NULL;
+	u8 bits = 0;
+	u8 imask = 0;
+	u8 cs_change = 0;
+	u16 txint_level = 0;
+	u16 clk_div = 0;
+	u32 speed = 0;
+	u32 cr0 = 0;
+
+	/* Get current state information */
+	message = dws->cur_msg;
+	transfer = dws->cur_transfer;
+	chip = dws->cur_chip;
+	spi = message->spi;
+
+	if (unlikely(!chip->clk_div))
+		chip->clk_div = dws->max_freq / chip->speed_hz;
+
+	if (message->state == ERROR_STATE) {
+		message->status = -EIO;
+		goto early_exit;
+	}
+
+	/* Handle end of message */
+	if (message->state == DONE_STATE) {
+		message->status = 0;
+		goto early_exit;
+	}
+
+	/* Delay if requested at end of transfer*/
+	if (message->state == RUNNING_STATE) {
+		previous = list_entry(transfer->transfer_list.prev,
+					struct spi_transfer,
+					transfer_list);
+		if (previous->delay_usecs)
+			udelay(previous->delay_usecs);
+	}
+
+	dws->n_bytes = chip->n_bytes;
+	dws->dma_width = chip->dma_width;
+	dws->cs_control = chip->cs_control;
+
+	dws->rx_dma = transfer->rx_dma;
+	dws->tx_dma = transfer->tx_dma;
+	dws->tx = (void *)transfer->tx_buf;
+	dws->tx_end = dws->tx + transfer->len;
+	dws->rx = transfer->rx_buf;
+	dws->rx_end = dws->rx + transfer->len;
+	dws->cs_change = transfer->cs_change;
+	dws->len = dws->cur_transfer->len;
+	if (chip != dws->prev_chip)
+		cs_change = 1;
+
+	cr0 = chip->cr0;
+
+	/* Handle per transfer options for bpw and speed */
+	if (transfer->speed_hz) {
+		speed = chip->speed_hz;
+
+		if (transfer->speed_hz != speed) {
+			speed = transfer->speed_hz;
+			if (speed > dws->max_freq) {
+				printk(KERN_ERR "MRST SPI0: unsupported"
+					"freq: %dHz\n", speed);
+				message->status = -EIO;
+				goto early_exit;
+			}
+
+			/* clk_div doesn't support odd number */
+			clk_div = dws->max_freq / speed;
+			clk_div = (clk_div + 1) & 0xfffe;
+
+			chip->speed_hz = speed;
+			chip->clk_div = clk_div;
+		}
+	}
+	if (transfer->bits_per_word) {
+		bits = transfer->bits_per_word;
+
+		switch (bits) {
+		case 8:
+		case 16:
+			dws->n_bytes = dws->dma_width = bits >> 3;
+			break;
+		default:
+			printk(KERN_ERR "MRST SPI0: unsupported bits:"
+				"%db\n", bits);
+			message->status = -EIO;
+			goto early_exit;
+		}
+
+		cr0 = (bits - 1)
+			| (chip->type << SPI_FRF_OFFSET)
+			| (spi->mode << SPI_MODE_OFFSET)
+			| (chip->tmode << SPI_TMOD_OFFSET);
+	}
+	message->state = RUNNING_STATE;
+
+	/*
+	 * Adjust transfer mode if necessary. Requires platform dependent
+	 * chipselect mechanism.
+	 */
+	if (dws->cs_control) {
+		if (dws->rx && dws->tx)
+			chip->tmode = SPI_TMOD_TR;
+		else if (dws->rx)
+			chip->tmode = SPI_TMOD_RO;
+		else
+			chip->tmode = SPI_TMOD_TO;
+
+		cr0 &= ~SPI_TMOD_MASK;
+		cr0 |= (chip->tmode << SPI_TMOD_OFFSET);
+	}
+
+	/* Check if current transfer is a DMA transaction */
+	dws->dma_mapped = map_dma_buffers(dws);
+
+	/*
+	 * Interrupt mode
+	 * we only need set the TXEI IRQ, as TX/RX always happen syncronizely
+	 */
+	if (!dws->dma_mapped && !chip->poll_mode) {
+		int templen = dws->len / dws->n_bytes;
+		txint_level = dws->fifo_len / 2;
+		txint_level = (templen > txint_level) ? txint_level : templen;
+
+		imask |= SPI_INT_TXEI | SPI_INT_TXOI | SPI_INT_RXUI | SPI_INT_RXOI;
+		dws->transfer_handler = interrupt_transfer;
+	}
+
+	/*
+	 * Reprogram registers only if
+	 *	1. chip select changes
+	 *	2. clk_div is changed
+	 *	3. control value changes
+	 */
+	if (dw_readw(dws, ctrl0) != cr0 || cs_change || clk_div || imask) {
+		spi_enable_chip(dws, 0);
+
+		if (dw_readw(dws, ctrl0) != cr0)
+			dw_writew(dws, ctrl0, cr0);
+
+		spi_set_clk(dws, clk_div ? clk_div : chip->clk_div);
+		spi_chip_sel(dws, spi->chip_select);
+
+		/* Set the interrupt mask, for poll mode just disable all int */
+		spi_mask_intr(dws, 0xff);
+		if (imask)
+			spi_umask_intr(dws, imask);
+		if (txint_level)
+			dw_writew(dws, txfltr, txint_level);
+
+		spi_enable_chip(dws, 1);
+		if (cs_change)
+			dws->prev_chip = chip;
+	}
+
+	if (dws->dma_mapped)
+		dws->dma_ops->dma_transfer(dws, cs_change);
+
+	if (chip->poll_mode)
+		poll_transfer(dws);
+
+	return;
+
+early_exit:
+	giveback(dws);
+	return;
+}
+
+static void pump_messages(struct work_struct *work)
+{
+	struct dw_spi *dws =
+		container_of(work, struct dw_spi, pump_messages);
+	unsigned long flags;
+
+	/* Lock queue and check for queue work */
+	spin_lock_irqsave(&dws->lock, flags);
+	if (list_empty(&dws->queue) || dws->run == QUEUE_STOPPED) {
+		dws->busy = 0;
+		spin_unlock_irqrestore(&dws->lock, flags);
+		return;
+	}
+
+	/* Make sure we are not already running a message */
+	if (dws->cur_msg) {
+		spin_unlock_irqrestore(&dws->lock, flags);
+		return;
+	}
+
+	/* Extract head of queue */
+	dws->cur_msg = list_entry(dws->queue.next, struct spi_message, queue);
+	list_del_init(&dws->cur_msg->queue);
+
+	/* Initial message state*/
+	dws->cur_msg->state = START_STATE;
+	dws->cur_transfer = list_entry(dws->cur_msg->transfers.next,
+						struct spi_transfer,
+						transfer_list);
+	dws->cur_chip = spi_get_ctldata(dws->cur_msg->spi);
+
+	/* Mark as busy and launch transfers */
+	tasklet_schedule(&dws->pump_transfers);
+
+	dws->busy = 1;
+	spin_unlock_irqrestore(&dws->lock, flags);
+}
+
+/* spi_device use this to queue in their spi_msg */
+static int dw_spi_transfer(struct spi_device *spi, struct spi_message *msg)
+{
+	struct dw_spi *dws = spi_master_get_devdata(spi->master);
+	unsigned long flags;
+
+	spin_lock_irqsave(&dws->lock, flags);
+
+	if (dws->run == QUEUE_STOPPED) {
+		spin_unlock_irqrestore(&dws->lock, flags);
+		return -ESHUTDOWN;
+	}
+
+	msg->actual_length = 0;
+	msg->status = -EINPROGRESS;
+	msg->state = START_STATE;
+
+	list_add_tail(&msg->queue, &dws->queue);
+
+	if (dws->run == QUEUE_RUNNING && !dws->busy) {
+
+		if (dws->cur_transfer || dws->cur_msg)
+			queue_work(dws->workqueue,
+					&dws->pump_messages);
+		else {
+			/* If no other data transaction in air, just go */
+			spin_unlock_irqrestore(&dws->lock, flags);
+			pump_messages(&dws->pump_messages);
+			return 0;
+		}
+	}
+
+	spin_unlock_irqrestore(&dws->lock, flags);
+	return 0;
+}
+
+/* This may be called twice for each spi dev */
+static int dw_spi_setup(struct spi_device *spi)
+{
+	struct dw_spi_chip *chip_info = NULL;
+	struct chip_data *chip;
+
+	if (spi->bits_per_word != 8 && spi->bits_per_word != 16)
+		return -EINVAL;
+
+	/* Only alloc on first setup */
+	chip = spi_get_ctldata(spi);
+	if (!chip) {
+		chip = kzalloc(sizeof(struct chip_data), GFP_KERNEL);
+		if (!chip)
+			return -ENOMEM;
+	}
+
+	/*
+	 * Protocol drivers may change the chip settings, so...
+	 * if chip_info exists, use it
+	 */
+	chip_info = spi->controller_data;
+
+	/* chip_info doesn't always exist */
+	if (chip_info) {
+		if (chip_info->cs_control)
+			chip->cs_control = chip_info->cs_control;
+
+		chip->poll_mode = chip_info->poll_mode;
+		chip->type = chip_info->type;
+
+		chip->rx_threshold = 0;
+		chip->tx_threshold = 0;
+
+		chip->enable_dma = chip_info->enable_dma;
+	}
+
+	if (spi->bits_per_word <= 8) {
+		chip->n_bytes = 1;
+		chip->dma_width = 1;
+	} else if (spi->bits_per_word <= 16) {
+		chip->n_bytes = 2;
+		chip->dma_width = 2;
+	} else {
+		/* Never take >16b case for MRST SPIC */
+		dev_err(&spi->dev, "invalid wordsize\n");
+		return -EINVAL;
+	}
+	chip->bits_per_word = spi->bits_per_word;
+
+	if (!spi->max_speed_hz) {
+		dev_err(&spi->dev, "No max speed HZ parameter\n");
+		return -EINVAL;
+	}
+	chip->speed_hz = spi->max_speed_hz;
+
+	chip->tmode = 0; /* Tx & Rx */
+	/* Default SPI mode is SCPOL = 0, SCPH = 0 */
+	chip->cr0 = (chip->bits_per_word - 1)
+			| (chip->type << SPI_FRF_OFFSET)
+			| (spi->mode  << SPI_MODE_OFFSET)
+			| (chip->tmode << SPI_TMOD_OFFSET);
+
+	spi_set_ctldata(spi, chip);
+	return 0;
+}
+
+static void dw_spi_cleanup(struct spi_device *spi)
+{
+	struct chip_data *chip = spi_get_ctldata(spi);
+	kfree(chip);
+}
+
+static int __devinit init_queue(struct dw_spi *dws)
+{
+	INIT_LIST_HEAD(&dws->queue);
+	spin_lock_init(&dws->lock);
+
+	dws->run = QUEUE_STOPPED;
+	dws->busy = 0;
+
+	tasklet_init(&dws->pump_transfers,
+			pump_transfers,	(unsigned long)dws);
+
+	INIT_WORK(&dws->pump_messages, pump_messages);
+	dws->workqueue = create_singlethread_workqueue(
+					dev_name(dws->master->dev.parent));
+	if (dws->workqueue == NULL)
+		return -EBUSY;
+
+	return 0;
+}
+
+static int start_queue(struct dw_spi *dws)
+{
+	unsigned long flags;
+
+	spin_lock_irqsave(&dws->lock, flags);
+
+	if (dws->run == QUEUE_RUNNING || dws->busy) {
+		spin_unlock_irqrestore(&dws->lock, flags);
+		return -EBUSY;
+	}
+
+	dws->run = QUEUE_RUNNING;
+	dws->cur_msg = NULL;
+	dws->cur_transfer = NULL;
+	dws->cur_chip = NULL;
+	dws->prev_chip = NULL;
+	spin_unlock_irqrestore(&dws->lock, flags);
+
+	queue_work(dws->workqueue, &dws->pump_messages);
+
+	return 0;
+}
+
+static int stop_queue(struct dw_spi *dws)
+{
+	unsigned long flags;
+	unsigned limit = 50;
+	int status = 0;
+
+	spin_lock_irqsave(&dws->lock, flags);
+	dws->run = QUEUE_STOPPED;
+	while ((!list_empty(&dws->queue) || dws->busy) && limit--) {
+		spin_unlock_irqrestore(&dws->lock, flags);
+		msleep(10);
+		spin_lock_irqsave(&dws->lock, flags);
+	}
+
+	if (!list_empty(&dws->queue) || dws->busy)
+		status = -EBUSY;
+	spin_unlock_irqrestore(&dws->lock, flags);
+
+	return status;
+}
+
+static int destroy_queue(struct dw_spi *dws)
+{
+	int status;
+
+	status = stop_queue(dws);
+	if (status != 0)
+		return status;
+	destroy_workqueue(dws->workqueue);
+	return 0;
+}
+
+/* Restart the controller, disable all interrupts, clean rx fifo */
+static void spi_hw_init(struct dw_spi *dws)
+{
+	spi_enable_chip(dws, 0);
+	spi_mask_intr(dws, 0xff);
+	spi_enable_chip(dws, 1);
+
+	/*
+	 * Try to detect the FIFO depth if not set by interface driver,
+	 * the depth could be from 2 to 256 from HW spec
+	 */
+	if (!dws->fifo_len) {
+		u32 fifo;
+		for (fifo = 2; fifo <= 257; fifo++) {
+			dw_writew(dws, txfltr, fifo);
+			if (fifo != dw_readw(dws, txfltr))
+				break;
+		}
+
+		dws->fifo_len = (fifo == 257) ? 0 : fifo;
+		dw_writew(dws, txfltr, 0);
+	}
+}
+
+int __devinit dw_spi_add_host(struct dw_spi *dws)
+{
+	struct spi_master *master;
+	int ret;
+
+	BUG_ON(dws == NULL);
+
+	master = spi_alloc_master(dws->parent_dev, 0);
+	if (!master) {
+		ret = -ENOMEM;
+		goto exit;
+	}
+
+	dws->master = master;
+	dws->type = SSI_MOTO_SPI;
+	dws->prev_chip = NULL;
+	dws->dma_inited = 0;
+	dws->dma_addr = (dma_addr_t)(dws->paddr + 0x60);
+
+	ret = request_irq(dws->irq, dw_spi_irq, IRQF_SHARED,
+			"dw_spi", dws);
+	if (ret < 0) {
+		dev_err(&master->dev, "can not get IRQ\n");
+		goto err_free_master;
+	}
+
+	master->mode_bits = SPI_CPOL | SPI_CPHA;
+	master->bus_num = dws->bus_num;
+	master->num_chipselect = dws->num_cs;
+	master->cleanup = dw_spi_cleanup;
+	master->setup = dw_spi_setup;
+	master->transfer = dw_spi_transfer;
+
+	/* Basic HW init */
+	spi_hw_init(dws);
+
+	if (dws->dma_ops && dws->dma_ops->dma_init) {
+		ret = dws->dma_ops->dma_init(dws);
+		if (ret) {
+			dev_warn(&master->dev, "DMA init failed\n");
+			dws->dma_inited = 0;
+		}
+	}
+
+	/* Initial and start queue */
+	ret = init_queue(dws);
+	if (ret) {
+		dev_err(&master->dev, "problem initializing queue\n");
+		goto err_diable_hw;
+	}
+	ret = start_queue(dws);
+	if (ret) {
+		dev_err(&master->dev, "problem starting queue\n");
+		goto err_diable_hw;
+	}
+
+	spi_master_set_devdata(master, dws);
+	ret = spi_register_master(master);
+	if (ret) {
+		dev_err(&master->dev, "problem registering spi master\n");
+		goto err_queue_alloc;
+	}
+
+	mrst_spi_debugfs_init(dws);
+	return 0;
+
+err_queue_alloc:
+	destroy_queue(dws);
+	if (dws->dma_ops && dws->dma_ops->dma_exit)
+		dws->dma_ops->dma_exit(dws);
+err_diable_hw:
+	spi_enable_chip(dws, 0);
+	free_irq(dws->irq, dws);
+err_free_master:
+	spi_master_put(master);
+exit:
+	return ret;
+}
+EXPORT_SYMBOL_GPL(dw_spi_add_host);
+
+void __devexit dw_spi_remove_host(struct dw_spi *dws)
+{
+	int status = 0;
+
+	if (!dws)
+		return;
+	mrst_spi_debugfs_remove(dws);
+
+	/* Remove the queue */
+	status = destroy_queue(dws);
+	if (status != 0)
+		dev_err(&dws->master->dev, "dw_spi_remove: workqueue will not "
+			"complete, message memory not freed\n");
+
+	if (dws->dma_ops && dws->dma_ops->dma_exit)
+		dws->dma_ops->dma_exit(dws);
+	spi_enable_chip(dws, 0);
+	/* Disable clk */
+	spi_set_clk(dws, 0);
+	free_irq(dws->irq, dws);
+
+	/* Disconnect from the SPI framework */
+	spi_unregister_master(dws->master);
+}
+EXPORT_SYMBOL_GPL(dw_spi_remove_host);
+
+int dw_spi_suspend_host(struct dw_spi *dws)
+{
+	int ret = 0;
+
+	ret = stop_queue(dws);
+	if (ret)
+		return ret;
+	spi_enable_chip(dws, 0);
+	spi_set_clk(dws, 0);
+	return ret;
+}
+EXPORT_SYMBOL_GPL(dw_spi_suspend_host);
+
+int dw_spi_resume_host(struct dw_spi *dws)
+{
+	int ret;
+
+	spi_hw_init(dws);
+	ret = start_queue(dws);
+	if (ret)
+		dev_err(&dws->master->dev, "fail to start queue (%d)\n", ret);
+	return ret;
+}
+EXPORT_SYMBOL_GPL(dw_spi_resume_host);
+
+MODULE_AUTHOR("Feng Tang <feng.tang@intel.com>");
+MODULE_DESCRIPTION("Driver for DesignWare SPI controller core");
+MODULE_LICENSE("GPL v2");