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, 1303 insertions, 0 deletions

diff --git a/drivers/spi/spi-topcliff-pch.c b/drivers/spi/spi-topcliff-pch.c
new file mode 100644
index 00000000000..79e48d45113
--- /dev/null
+++ b/drivers/spi/spi-topcliff-pch.c
@@ -0,0 +1,1303 @@
+/*
+ * SPI bus driver for the Topcliff PCH used by Intel SoCs
+ *
+ * Copyright (C) 2010 OKI SEMICONDUCTOR Co., LTD.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; version 2 of the License.
+ *
+ * This program is distributed in the hope that 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., 59 Temple Place, Suite 330, Boston, MA  02111-1307, USA.
+ */
+
+#include <linux/delay.h>
+#include <linux/pci.h>
+#include <linux/wait.h>
+#include <linux/spi/spi.h>
+#include <linux/interrupt.h>
+#include <linux/sched.h>
+#include <linux/spi/spidev.h>
+#include <linux/module.h>
+#include <linux/device.h>
+
+/* Register offsets */
+#define PCH_SPCR		0x00	/* SPI control register */
+#define PCH_SPBRR		0x04	/* SPI baud rate register */
+#define PCH_SPSR		0x08	/* SPI status register */
+#define PCH_SPDWR		0x0C	/* SPI write data register */
+#define PCH_SPDRR		0x10	/* SPI read data register */
+#define PCH_SSNXCR		0x18	/* SSN Expand Control Register */
+#define PCH_SRST		0x1C	/* SPI reset register */
+
+#define PCH_SPSR_TFD		0x000007C0
+#define PCH_SPSR_RFD		0x0000F800
+
+#define PCH_READABLE(x)		(((x) & PCH_SPSR_RFD)>>11)
+#define PCH_WRITABLE(x)		(((x) & PCH_SPSR_TFD)>>6)
+
+#define PCH_RX_THOLD		7
+#define PCH_RX_THOLD_MAX	15
+
+#define PCH_MAX_BAUDRATE	5000000
+#define PCH_MAX_FIFO_DEPTH	16
+
+#define STATUS_RUNNING		1
+#define STATUS_EXITING		2
+#define PCH_SLEEP_TIME		10
+
+#define PCH_ADDRESS_SIZE	0x20
+
+#define SSN_LOW			0x02U
+#define SSN_NO_CONTROL		0x00U
+#define PCH_MAX_CS		0xFF
+#define PCI_DEVICE_ID_GE_SPI	0x8816
+
+#define SPCR_SPE_BIT		(1 << 0)
+#define SPCR_MSTR_BIT		(1 << 1)
+#define SPCR_LSBF_BIT		(1 << 4)
+#define SPCR_CPHA_BIT		(1 << 5)
+#define SPCR_CPOL_BIT		(1 << 6)
+#define SPCR_TFIE_BIT		(1 << 8)
+#define SPCR_RFIE_BIT		(1 << 9)
+#define SPCR_FIE_BIT		(1 << 10)
+#define SPCR_ORIE_BIT		(1 << 11)
+#define SPCR_MDFIE_BIT		(1 << 12)
+#define SPCR_FICLR_BIT		(1 << 24)
+#define SPSR_TFI_BIT		(1 << 0)
+#define SPSR_RFI_BIT		(1 << 1)
+#define SPSR_FI_BIT		(1 << 2)
+#define SPBRR_SIZE_BIT		(1 << 10)
+
+#define PCH_ALL			(SPCR_TFIE_BIT|SPCR_RFIE_BIT|SPCR_FIE_BIT|SPCR_ORIE_BIT|SPCR_MDFIE_BIT)
+
+#define SPCR_RFIC_FIELD		20
+#define SPCR_TFIC_FIELD		16
+
+#define SPSR_INT_BITS		0x1F
+#define MASK_SPBRR_SPBR_BITS	(~((1 << 10) - 1))
+#define MASK_RFIC_SPCR_BITS	(~(0xf << 20))
+#define MASK_TFIC_SPCR_BITS	(~(0xf000f << 12))
+
+#define PCH_CLOCK_HZ		50000000
+#define PCH_MAX_SPBR		1023
+
+
+/**
+ * struct pch_spi_data - Holds the SPI channel specific details
+ * @io_remap_addr:		The remapped PCI base address
+ * @master:			Pointer to the SPI master structure
+ * @work:			Reference to work queue handler
+ * @wk:				Workqueue for carrying out execution of the
+ *				requests
+ * @wait:			Wait queue for waking up upon receiving an
+ *				interrupt.
+ * @transfer_complete:		Status of SPI Transfer
+ * @bcurrent_msg_processing:	Status flag for message processing
+ * @lock:			Lock for protecting this structure
+ * @queue:			SPI Message queue
+ * @status:			Status of the SPI driver
+ * @bpw_len:			Length of data to be transferred in bits per
+ *				word
+ * @transfer_active:		Flag showing active transfer
+ * @tx_index:			Transmit data count; for bookkeeping during
+ *				transfer
+ * @rx_index:			Receive data count; for bookkeeping during
+ *				transfer
+ * @tx_buff:			Buffer for data to be transmitted
+ * @rx_index:			Buffer for Received data
+ * @n_curnt_chip:		The chip number that this SPI driver currently
+ *				operates on
+ * @current_chip:		Reference to the current chip that this SPI
+ *				driver currently operates on
+ * @current_msg:		The current message that this SPI driver is
+ *				handling
+ * @cur_trans:			The current transfer that this SPI driver is
+ *				handling
+ * @board_dat:			Reference to the SPI device data structure
+ */
+struct pch_spi_data {
+	void __iomem *io_remap_addr;
+	struct spi_master *master;
+	struct work_struct work;
+	struct workqueue_struct *wk;
+	wait_queue_head_t wait;
+	u8 transfer_complete;
+	u8 bcurrent_msg_processing;
+	spinlock_t lock;
+	struct list_head queue;
+	u8 status;
+	u32 bpw_len;
+	u8 transfer_active;
+	u32 tx_index;
+	u32 rx_index;
+	u16 *pkt_tx_buff;
+	u16 *pkt_rx_buff;
+	u8 n_curnt_chip;
+	struct spi_device *current_chip;
+	struct spi_message *current_msg;
+	struct spi_transfer *cur_trans;
+	struct pch_spi_board_data *board_dat;
+};
+
+/**
+ * struct pch_spi_board_data - Holds the SPI device specific details
+ * @pdev:		Pointer to the PCI device
+ * @irq_reg_sts:	Status of IRQ registration
+ * @pci_req_sts:	Status of pci_request_regions
+ * @suspend_sts:	Status of suspend
+ * @data:		Pointer to SPI channel data structure
+ */
+struct pch_spi_board_data {
+	struct pci_dev *pdev;
+	u8 irq_reg_sts;
+	u8 pci_req_sts;
+	u8 suspend_sts;
+	struct pch_spi_data *data;
+};
+
+static struct pci_device_id pch_spi_pcidev_id[] = {
+	{PCI_DEVICE(PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_GE_SPI)},
+	{0,}
+};
+
+/**
+ * pch_spi_writereg() - Performs  register writes
+ * @master:	Pointer to struct spi_master.
+ * @idx:	Register offset.
+ * @val:	Value to be written to register.
+ */
+static inline void pch_spi_writereg(struct spi_master *master, int idx, u32 val)
+{
+	struct pch_spi_data *data = spi_master_get_devdata(master);
+	iowrite32(val, (data->io_remap_addr + idx));
+}
+
+/**
+ * pch_spi_readreg() - Performs register reads
+ * @master:	Pointer to struct spi_master.
+ * @idx:	Register offset.
+ */
+static inline u32 pch_spi_readreg(struct spi_master *master, int idx)
+{
+	struct pch_spi_data *data = spi_master_get_devdata(master);
+	return ioread32(data->io_remap_addr + idx);
+}
+
+static inline void pch_spi_setclr_reg(struct spi_master *master, int idx,
+				      u32 set, u32 clr)
+{
+	u32 tmp = pch_spi_readreg(master, idx);
+	tmp = (tmp & ~clr) | set;
+	pch_spi_writereg(master, idx, tmp);
+}
+
+static void pch_spi_set_master_mode(struct spi_master *master)
+{
+	pch_spi_setclr_reg(master, PCH_SPCR, SPCR_MSTR_BIT, 0);
+}
+
+/**
+ * pch_spi_clear_fifo() - Clears the Transmit and Receive FIFOs
+ * @master:	Pointer to struct spi_master.
+ */
+static void pch_spi_clear_fifo(struct spi_master *master)
+{
+	pch_spi_setclr_reg(master, PCH_SPCR, SPCR_FICLR_BIT, 0);
+	pch_spi_setclr_reg(master, PCH_SPCR, 0, SPCR_FICLR_BIT);
+}
+
+static void pch_spi_handler_sub(struct pch_spi_data *data, u32 reg_spsr_val,
+				void __iomem *io_remap_addr)
+{
+	u32 n_read, tx_index, rx_index, bpw_len;
+	u16 *pkt_rx_buffer, *pkt_tx_buff;
+	int read_cnt;
+	u32 reg_spcr_val;
+	void __iomem *spsr;
+	void __iomem *spdrr;
+	void __iomem *spdwr;
+
+	spsr = io_remap_addr + PCH_SPSR;
+	iowrite32(reg_spsr_val, spsr);
+
+	if (data->transfer_active) {
+		rx_index = data->rx_index;
+		tx_index = data->tx_index;
+		bpw_len = data->bpw_len;
+		pkt_rx_buffer = data->pkt_rx_buff;
+		pkt_tx_buff = data->pkt_tx_buff;
+
+		spdrr = io_remap_addr + PCH_SPDRR;
+		spdwr = io_remap_addr + PCH_SPDWR;
+
+		n_read = PCH_READABLE(reg_spsr_val);
+
+		for (read_cnt = 0; (read_cnt < n_read); read_cnt++) {
+			pkt_rx_buffer[rx_index++] = ioread32(spdrr);
+			if (tx_index < bpw_len)
+				iowrite32(pkt_tx_buff[tx_index++], spdwr);
+		}
+
+		/* disable RFI if not needed */
+		if ((bpw_len - rx_index) <= PCH_MAX_FIFO_DEPTH) {
+			reg_spcr_val = ioread32(io_remap_addr + PCH_SPCR);
+			reg_spcr_val &= ~SPCR_RFIE_BIT; /* disable RFI */
+
+			/* reset rx threshold */
+			reg_spcr_val &= MASK_RFIC_SPCR_BITS;
+			reg_spcr_val |= (PCH_RX_THOLD_MAX << SPCR_RFIC_FIELD);
+			iowrite32(((reg_spcr_val) &= (~(SPCR_RFIE_BIT))),
+				 (io_remap_addr + PCH_SPCR));
+		}
+
+		/* update counts */
+		data->tx_index = tx_index;
+		data->rx_index = rx_index;
+
+	}
+
+	/* if transfer complete interrupt */
+	if (reg_spsr_val & SPSR_FI_BIT) {
+		/* disable FI & RFI interrupts */
+		pch_spi_setclr_reg(data->master, PCH_SPCR, 0,
+				   SPCR_FIE_BIT | SPCR_RFIE_BIT);
+
+		/* transfer is completed;inform pch_spi_process_messages */
+		data->transfer_complete = true;
+		wake_up(&data->wait);
+	}
+}
+
+/**
+ * pch_spi_handler() - Interrupt handler
+ * @irq:	The interrupt number.
+ * @dev_id:	Pointer to struct pch_spi_board_data.
+ */
+static irqreturn_t pch_spi_handler(int irq, void *dev_id)
+{
+	u32 reg_spsr_val;
+	struct pch_spi_data *data;
+	void __iomem *spsr;
+	void __iomem *io_remap_addr;
+	irqreturn_t ret = IRQ_NONE;
+	struct pch_spi_board_data *board_dat = dev_id;
+
+	if (board_dat->suspend_sts) {
+		dev_dbg(&board_dat->pdev->dev,
+			"%s returning due to suspend\n", __func__);
+		return IRQ_NONE;
+	}
+
+	data = board_dat->data;
+	io_remap_addr = data->io_remap_addr;
+	spsr = io_remap_addr + PCH_SPSR;
+
+	reg_spsr_val = ioread32(spsr);
+
+	/* Check if the interrupt is for SPI device */
+	if (reg_spsr_val & (SPSR_FI_BIT | SPSR_RFI_BIT)) {
+		pch_spi_handler_sub(data, reg_spsr_val, io_remap_addr);
+		ret = IRQ_HANDLED;
+	}
+
+	dev_dbg(&board_dat->pdev->dev, "%s EXIT return value=%d\n",
+		__func__, ret);
+
+	return ret;
+}
+
+/**
+ * pch_spi_set_baud_rate() - Sets SPBR field in SPBRR
+ * @master:	Pointer to struct spi_master.
+ * @speed_hz:	Baud rate.
+ */
+static void pch_spi_set_baud_rate(struct spi_master *master, u32 speed_hz)
+{
+	u32 n_spbr = PCH_CLOCK_HZ / (speed_hz * 2);
+
+	/* if baud rate is less than we can support limit it */
+	if (n_spbr > PCH_MAX_SPBR)
+		n_spbr = PCH_MAX_SPBR;
+
+	pch_spi_setclr_reg(master, PCH_SPBRR, n_spbr, ~MASK_SPBRR_SPBR_BITS);
+}
+
+/**
+ * pch_spi_set_bits_per_word() - Sets SIZE field in SPBRR
+ * @master:		Pointer to struct spi_master.
+ * @bits_per_word:	Bits per word for SPI transfer.
+ */
+static void pch_spi_set_bits_per_word(struct spi_master *master,
+				      u8 bits_per_word)
+{
+	if (bits_per_word == 8)
+		pch_spi_setclr_reg(master, PCH_SPBRR, 0, SPBRR_SIZE_BIT);
+	else
+		pch_spi_setclr_reg(master, PCH_SPBRR, SPBRR_SIZE_BIT, 0);
+}
+
+/**
+ * pch_spi_setup_transfer() - Configures the PCH SPI hardware for transfer
+ * @spi:	Pointer to struct spi_device.
+ */
+static void pch_spi_setup_transfer(struct spi_device *spi)
+{
+	u32 flags = 0;
+
+	dev_dbg(&spi->dev, "%s SPBRR content =%x setting baud rate=%d\n",
+		__func__, pch_spi_readreg(spi->master, PCH_SPBRR),
+		spi->max_speed_hz);
+	pch_spi_set_baud_rate(spi->master, spi->max_speed_hz);
+
+	/* set bits per word */
+	pch_spi_set_bits_per_word(spi->master, spi->bits_per_word);
+
+	if (!(spi->mode & SPI_LSB_FIRST))
+		flags |= SPCR_LSBF_BIT;
+	if (spi->mode & SPI_CPOL)
+		flags |= SPCR_CPOL_BIT;
+	if (spi->mode & SPI_CPHA)
+		flags |= SPCR_CPHA_BIT;
+	pch_spi_setclr_reg(spi->master, PCH_SPCR, flags,
+			   (SPCR_LSBF_BIT | SPCR_CPOL_BIT | SPCR_CPHA_BIT));
+
+	/* Clear the FIFO by toggling  FICLR to 1 and back to 0 */
+	pch_spi_clear_fifo(spi->master);
+}
+
+/**
+ * pch_spi_reset() - Clears SPI registers
+ * @master:	Pointer to struct spi_master.
+ */
+static void pch_spi_reset(struct spi_master *master)
+{
+	/* write 1 to reset SPI */
+	pch_spi_writereg(master, PCH_SRST, 0x1);
+
+	/* clear reset */
+	pch_spi_writereg(master, PCH_SRST, 0x0);
+}
+
+static int pch_spi_setup(struct spi_device *pspi)
+{
+	/* check bits per word */
+	if (pspi->bits_per_word == 0) {
+		pspi->bits_per_word = 8;
+		dev_dbg(&pspi->dev, "%s 8 bits per word\n", __func__);
+	}
+
+	if ((pspi->bits_per_word != 8) && (pspi->bits_per_word != 16)) {
+		dev_err(&pspi->dev, "%s Invalid bits per word\n", __func__);
+		return -EINVAL;
+	}
+
+	/* Check baud rate setting */
+	/* if baud rate of chip is greater than
+	   max we can support,return error */
+	if ((pspi->max_speed_hz) > PCH_MAX_BAUDRATE)
+		pspi->max_speed_hz = PCH_MAX_BAUDRATE;
+
+	dev_dbg(&pspi->dev, "%s MODE = %x\n", __func__,
+		(pspi->mode) & (SPI_CPOL | SPI_CPHA));
+
+	return 0;
+}
+
+static int pch_spi_transfer(struct spi_device *pspi, struct spi_message *pmsg)
+{
+
+	struct spi_transfer *transfer;
+	struct pch_spi_data *data = spi_master_get_devdata(pspi->master);
+	int retval;
+	unsigned long flags;
+
+	/* validate spi message and baud rate */
+	if (unlikely(list_empty(&pmsg->transfers) == 1)) {
+		dev_err(&pspi->dev, "%s list empty\n", __func__);
+		retval = -EINVAL;
+		goto err_out;
+	}
+
+	if (unlikely(pspi->max_speed_hz == 0)) {
+		dev_err(&pspi->dev, "%s pch_spi_tranfer maxspeed=%d\n",
+			__func__, pspi->max_speed_hz);
+		retval = -EINVAL;
+		goto err_out;
+	}
+
+	dev_dbg(&pspi->dev, "%s Transfer List not empty. "
+		"Transfer Speed is set.\n", __func__);
+
+	/* validate Tx/Rx buffers and Transfer length */
+	list_for_each_entry(transfer, &pmsg->transfers, transfer_list) {
+		if (!transfer->tx_buf && !transfer->rx_buf) {
+			dev_err(&pspi->dev,
+				"%s Tx and Rx buffer NULL\n", __func__);
+			retval = -EINVAL;
+			goto err_out;
+		}
+
+		if (!transfer->len) {
+			dev_err(&pspi->dev, "%s Transfer length invalid\n",
+				__func__);
+			retval = -EINVAL;
+			goto err_out;
+		}
+
+		dev_dbg(&pspi->dev, "%s Tx/Rx buffer valid. Transfer length"
+			" valid\n", __func__);
+
+		/* if baud rate hs been specified validate the same */
+		if (transfer->speed_hz > PCH_MAX_BAUDRATE)
+			transfer->speed_hz = PCH_MAX_BAUDRATE;
+
+		/* if bits per word has been specified validate the same */
+		if (transfer->bits_per_word) {
+			if ((transfer->bits_per_word != 8)
+			    && (transfer->bits_per_word != 16)) {
+				retval = -EINVAL;
+				dev_err(&pspi->dev,
+					"%s Invalid bits per word\n", __func__);
+				goto err_out;
+			}
+		}
+	}
+
+	spin_lock_irqsave(&data->lock, flags);
+
+	/* We won't process any messages if we have been asked to terminate */
+	if (data->status == STATUS_EXITING) {
+		dev_err(&pspi->dev, "%s status = STATUS_EXITING.\n", __func__);
+		retval = -ESHUTDOWN;
+		goto err_return_spinlock;
+	}
+
+	/* If suspended ,return -EINVAL */
+	if (data->board_dat->suspend_sts) {
+		dev_err(&pspi->dev, "%s suspend; returning EINVAL\n", __func__);
+		retval = -EINVAL;
+		goto err_return_spinlock;
+	}
+
+	/* set status of message */
+	pmsg->actual_length = 0;
+	dev_dbg(&pspi->dev, "%s - pmsg->status =%d\n", __func__, pmsg->status);
+
+	pmsg->status = -EINPROGRESS;
+
+	/* add message to queue */
+	list_add_tail(&pmsg->queue, &data->queue);
+	dev_dbg(&pspi->dev, "%s - Invoked list_add_tail\n", __func__);
+
+	/* schedule work queue to run */
+	queue_work(data->wk, &data->work);
+	dev_dbg(&pspi->dev, "%s - Invoked queue work\n", __func__);
+
+	retval = 0;
+
+err_return_spinlock:
+	spin_unlock_irqrestore(&data->lock, flags);
+err_out:
+	dev_dbg(&pspi->dev, "%s RETURN=%d\n", __func__, retval);
+	return retval;
+}
+
+static inline void pch_spi_select_chip(struct pch_spi_data *data,
+				       struct spi_device *pspi)
+{
+	if (data->current_chip != NULL) {
+		if (pspi->chip_select != data->n_curnt_chip) {
+			dev_dbg(&pspi->dev, "%s : different slave\n", __func__);
+			data->current_chip = NULL;
+		}
+	}
+
+	data->current_chip = pspi;
+
+	data->n_curnt_chip = data->current_chip->chip_select;
+
+	dev_dbg(&pspi->dev, "%s :Invoking pch_spi_setup_transfer\n", __func__);
+	pch_spi_setup_transfer(pspi);
+}
+
+static void pch_spi_set_tx(struct pch_spi_data *data, int *bpw,
+			   struct spi_message **ppmsg)
+{
+	int size;
+	u32 n_writes;
+	int j;
+	struct spi_message *pmsg;
+	const u8 *tx_buf;
+	const u16 *tx_sbuf;
+
+	pmsg = *ppmsg;
+
+	/* set baud rate if needed */
+	if (data->cur_trans->speed_hz) {
+		dev_dbg(&data->master->dev, "%s:setting baud rate\n", __func__);
+		pch_spi_set_baud_rate(data->master, data->cur_trans->speed_hz);
+	}
+
+	/* set bits per word if needed */
+	if (data->cur_trans->bits_per_word &&
+	    (data->current_msg->spi->bits_per_word != data->cur_trans->bits_per_word)) {
+		dev_dbg(&data->master->dev, "%s:set bits per word\n", __func__);
+		pch_spi_set_bits_per_word(data->master,
+					  data->cur_trans->bits_per_word);
+		*bpw = data->cur_trans->bits_per_word;
+	} else {
+		*bpw = data->current_msg->spi->bits_per_word;
+	}
+
+	/* reset Tx/Rx index */
+	data->tx_index = 0;
+	data->rx_index = 0;
+
+	data->bpw_len = data->cur_trans->len / (*bpw / 8);
+
+	/* find alloc size */
+	size = data->cur_trans->len * sizeof(*data->pkt_tx_buff);
+
+	/* allocate memory for pkt_tx_buff & pkt_rx_buffer */
+	data->pkt_tx_buff = kzalloc(size, GFP_KERNEL);
+	if (data->pkt_tx_buff != NULL) {
+		data->pkt_rx_buff = kzalloc(size, GFP_KERNEL);
+		if (!data->pkt_rx_buff)
+			kfree(data->pkt_tx_buff);
+	}
+
+	if (!data->pkt_rx_buff) {
+		/* flush queue and set status of all transfers to -ENOMEM */
+		dev_err(&data->master->dev, "%s :kzalloc failed\n", __func__);
+		list_for_each_entry(pmsg, data->queue.next, queue) {
+			pmsg->status = -ENOMEM;
+
+			if (pmsg->complete != 0)
+				pmsg->complete(pmsg->context);
+
+			/* delete from queue */
+			list_del_init(&pmsg->queue);
+		}
+		return;
+	}
+
+	/* copy Tx Data */
+	if (data->cur_trans->tx_buf != NULL) {
+		if (*bpw == 8) {
+			tx_buf = data->cur_trans->tx_buf;
+			for (j = 0; j < data->bpw_len; j++)
+				data->pkt_tx_buff[j] = *tx_buf++;
+		} else {
+			tx_sbuf = data->cur_trans->tx_buf;
+			for (j = 0; j < data->bpw_len; j++)
+				data->pkt_tx_buff[j] = *tx_sbuf++;
+		}
+	}
+
+	/* if len greater than PCH_MAX_FIFO_DEPTH, write 16,else len bytes */
+	n_writes = data->bpw_len;
+	if (n_writes > PCH_MAX_FIFO_DEPTH)
+		n_writes = PCH_MAX_FIFO_DEPTH;
+
+	dev_dbg(&data->master->dev, "\n%s:Pulling down SSN low - writing "
+		"0x2 to SSNXCR\n", __func__);
+	pch_spi_writereg(data->master, PCH_SSNXCR, SSN_LOW);
+
+	for (j = 0; j < n_writes; j++)
+		pch_spi_writereg(data->master, PCH_SPDWR, data->pkt_tx_buff[j]);
+
+	/* update tx_index */
+	data->tx_index = j;
+
+	/* reset transfer complete flag */
+	data->transfer_complete = false;
+	data->transfer_active = true;
+}
+
+
+static void pch_spi_nomore_transfer(struct pch_spi_data *data,
+						struct spi_message *pmsg)
+{
+	dev_dbg(&data->master->dev, "%s called\n", __func__);
+	/* Invoke complete callback
+	 * [To the spi core..indicating end of transfer] */
+	data->current_msg->status = 0;
+
+	if (data->current_msg->complete != 0) {
+		dev_dbg(&data->master->dev,
+			"%s:Invoking callback of SPI core\n", __func__);
+		data->current_msg->complete(data->current_msg->context);
+	}
+
+	/* update status in global variable */
+	data->bcurrent_msg_processing = false;
+
+	dev_dbg(&data->master->dev,
+		"%s:data->bcurrent_msg_processing = false\n", __func__);
+
+	data->current_msg = NULL;
+	data->cur_trans = NULL;
+
+	/* check if we have items in list and not suspending
+	 * return 1 if list empty */
+	if ((list_empty(&data->queue) == 0) &&
+	    (!data->board_dat->suspend_sts) &&
+	    (data->status != STATUS_EXITING)) {
+		/* We have some more work to do (either there is more tranint
+		 * bpw;sfer requests in the current message or there are
+		 *more messages)
+		 */
+		dev_dbg(&data->master->dev, "%s:Invoke queue_work\n", __func__);
+		queue_work(data->wk, &data->work);
+	} else if (data->board_dat->suspend_sts ||
+		   data->status == STATUS_EXITING) {
+		dev_dbg(&data->master->dev,
+			"%s suspend/remove initiated, flushing queue\n",
+			__func__);
+		list_for_each_entry(pmsg, data->queue.next, queue) {
+			pmsg->status = -EIO;
+
+			if (pmsg->complete)
+				pmsg->complete(pmsg->context);
+
+			/* delete from queue */
+			list_del_init(&pmsg->queue);
+		}
+	}
+}
+
+static void pch_spi_set_ir(struct pch_spi_data *data)
+{
+	/* enable interrupts */
+	if ((data->bpw_len) > PCH_MAX_FIFO_DEPTH) {
+		/* set receive threshold to PCH_RX_THOLD */
+		pch_spi_setclr_reg(data->master, PCH_SPCR,
+				   PCH_RX_THOLD << SPCR_RFIC_FIELD,
+				   ~MASK_RFIC_SPCR_BITS);
+		/* enable FI and RFI interrupts */
+		pch_spi_setclr_reg(data->master, PCH_SPCR,
+				   SPCR_RFIE_BIT | SPCR_FIE_BIT, 0);
+	} else {
+		/* set receive threshold to maximum */
+		pch_spi_setclr_reg(data->master, PCH_SPCR,
+				   PCH_RX_THOLD_MAX << SPCR_TFIC_FIELD,
+				   ~MASK_TFIC_SPCR_BITS);
+		/* enable FI interrupt */
+		pch_spi_setclr_reg(data->master, PCH_SPCR, SPCR_FIE_BIT, 0);
+	}
+
+	dev_dbg(&data->master->dev,
+		"%s:invoking pch_spi_set_enable to enable SPI\n", __func__);
+
+	/* SPI set enable */
+	pch_spi_setclr_reg(data->current_chip->master, PCH_SPCR, SPCR_SPE_BIT, 0);
+
+	/* Wait until the transfer completes; go to sleep after
+				 initiating the transfer. */
+	dev_dbg(&data->master->dev,
+		"%s:waiting for transfer to get over\n", __func__);
+
+	wait_event_interruptible(data->wait, data->transfer_complete);
+
+	pch_spi_writereg(data->master, PCH_SSNXCR, SSN_NO_CONTROL);
+	dev_dbg(&data->master->dev,
+		"%s:no more control over SSN-writing 0 to SSNXCR.", __func__);
+
+	data->transfer_active = false;
+	dev_dbg(&data->master->dev,
+		"%s set data->transfer_active = false\n", __func__);
+
+	/* clear all interrupts */
+	pch_spi_writereg(data->master, PCH_SPSR,
+			 pch_spi_readreg(data->master, PCH_SPSR));
+	/* disable interrupts */
+	pch_spi_setclr_reg(data->master, PCH_SPCR, 0, PCH_ALL);
+}
+
+static void pch_spi_copy_rx_data(struct pch_spi_data *data, int bpw)
+{
+	int j;
+	u8 *rx_buf;
+	u16 *rx_sbuf;
+
+	/* copy Rx Data */
+	if (!data->cur_trans->rx_buf)
+		return;
+
+	if (bpw == 8) {
+		rx_buf = data->cur_trans->rx_buf;
+		for (j = 0; j < data->bpw_len; j++)
+			*rx_buf++ = data->pkt_rx_buff[j] & 0xFF;
+	} else {
+		rx_sbuf = data->cur_trans->rx_buf;
+		for (j = 0; j < data->bpw_len; j++)
+			*rx_sbuf++ = data->pkt_rx_buff[j];
+	}
+}
+
+
+static void pch_spi_process_messages(struct work_struct *pwork)
+{
+	struct spi_message *pmsg;
+	struct pch_spi_data *data;
+	int bpw;
+
+	data = container_of(pwork, struct pch_spi_data, work);
+	dev_dbg(&data->master->dev, "%s data initialized\n", __func__);
+
+	spin_lock(&data->lock);
+
+	/* check if suspend has been initiated;if yes flush queue */
+	if (data->board_dat->suspend_sts || (data->status == STATUS_EXITING)) {
+		dev_dbg(&data->master->dev,
+			"%s suspend/remove initiated,flushing queue\n",
+			__func__);
+
+		list_for_each_entry(pmsg, data->queue.next, queue) {
+			pmsg->status = -EIO;
+
+			if (pmsg->complete != 0) {
+				spin_unlock(&data->lock);
+				pmsg->complete(pmsg->context);
+				spin_lock(&data->lock);
+			}
+
+			/* delete from queue */
+			list_del_init(&pmsg->queue);
+		}
+
+		spin_unlock(&data->lock);
+		return;
+	}
+
+	data->bcurrent_msg_processing = true;
+	dev_dbg(&data->master->dev,
+		"%s Set data->bcurrent_msg_processing= true\n", __func__);
+
+	/* Get the message from the queue and delete it from there. */
+	data->current_msg = list_entry(data->queue.next, struct spi_message,
+					queue);
+
+	list_del_init(&data->current_msg->queue);
+
+	data->current_msg->status = 0;
+
+	pch_spi_select_chip(data, data->current_msg->spi);
+
+	spin_unlock(&data->lock);
+
+	do {
+		/* If we are already processing a message get the next
+		transfer structure from the message otherwise retrieve
+		the 1st transfer request from the message. */
+		spin_lock(&data->lock);
+
+		if (data->cur_trans == NULL) {
+			data->cur_trans =
+			    list_entry(data->current_msg->transfers.
+				       next, struct spi_transfer,
+				       transfer_list);
+			dev_dbg(&data->master->dev,
+				"%s :Getting 1st transfer message\n", __func__);
+		} else {
+			data->cur_trans =
+			    list_entry(data->cur_trans->transfer_list.next,
+				       struct spi_transfer,
+				       transfer_list);
+			dev_dbg(&data->master->dev,
+				"%s :Getting next transfer message\n",
+				__func__);
+		}
+
+		spin_unlock(&data->lock);
+
+		pch_spi_set_tx(data, &bpw, &pmsg);
+
+		/* Control interrupt*/
+		pch_spi_set_ir(data);
+
+		/* Disable SPI transfer */
+		pch_spi_setclr_reg(data->current_chip->master, PCH_SPCR, 0,
+				   SPCR_SPE_BIT);
+
+		/* clear FIFO */
+		pch_spi_clear_fifo(data->master);
+
+		/* copy Rx Data */
+		pch_spi_copy_rx_data(data, bpw);
+
+		/* free memory */
+		kfree(data->pkt_rx_buff);
+		data->pkt_rx_buff = NULL;
+
+		kfree(data->pkt_tx_buff);
+		data->pkt_tx_buff = NULL;
+
+		/* increment message count */
+		data->current_msg->actual_length += data->cur_trans->len;
+
+		dev_dbg(&data->master->dev,
+			"%s:data->current_msg->actual_length=%d\n",
+			__func__, data->current_msg->actual_length);
+
+		/* check for delay */
+		if (data->cur_trans->delay_usecs) {
+			dev_dbg(&data->master->dev, "%s:"
+				"delay in usec=%d\n", __func__,
+				data->cur_trans->delay_usecs);
+			udelay(data->cur_trans->delay_usecs);
+		}
+
+		spin_lock(&data->lock);
+
+		/* No more transfer in this message. */
+		if ((data->cur_trans->transfer_list.next) ==
+		    &(data->current_msg->transfers)) {
+			pch_spi_nomore_transfer(data, pmsg);
+		}
+
+		spin_unlock(&data->lock);
+
+	} while (data->cur_trans != NULL);
+}
+
+static void pch_spi_free_resources(struct pch_spi_board_data *board_dat)
+{
+	dev_dbg(&board_dat->pdev->dev, "%s ENTRY\n", __func__);
+
+	/* free workqueue */
+	if (board_dat->data->wk != NULL) {
+		destroy_workqueue(board_dat->data->wk);
+		board_dat->data->wk = NULL;
+		dev_dbg(&board_dat->pdev->dev,
+			"%s destroy_workqueue invoked successfully\n",
+			__func__);
+	}
+
+	/* disable interrupts & free IRQ */
+	if (board_dat->irq_reg_sts) {
+		/* disable interrupts */
+		pch_spi_setclr_reg(board_dat->data->master, PCH_SPCR, 0,
+				   PCH_ALL);
+
+		/* free IRQ */
+		free_irq(board_dat->pdev->irq, board_dat);
+
+		dev_dbg(&board_dat->pdev->dev,
+			"%s free_irq invoked successfully\n", __func__);
+
+		board_dat->irq_reg_sts = false;
+	}
+
+	/* unmap PCI base address */
+	if (board_dat->data->io_remap_addr != 0) {
+		pci_iounmap(board_dat->pdev, board_dat->data->io_remap_addr);
+
+		board_dat->data->io_remap_addr = 0;
+
+		dev_dbg(&board_dat->pdev->dev,
+			"%s pci_iounmap invoked successfully\n", __func__);
+	}
+
+	/* release PCI region */
+	if (board_dat->pci_req_sts) {
+		pci_release_regions(board_dat->pdev);
+		dev_dbg(&board_dat->pdev->dev,
+			"%s pci_release_regions invoked successfully\n",
+			__func__);
+		board_dat->pci_req_sts = false;
+	}
+}
+
+static int pch_spi_get_resources(struct pch_spi_board_data *board_dat)
+{
+	void __iomem *io_remap_addr;
+	int retval;
+	dev_dbg(&board_dat->pdev->dev, "%s ENTRY\n", __func__);
+
+	/* create workqueue */
+	board_dat->data->wk = create_singlethread_workqueue(KBUILD_MODNAME);
+	if (!board_dat->data->wk) {
+		dev_err(&board_dat->pdev->dev,
+			"%s create_singlet hread_workqueue failed\n", __func__);
+		retval = -EBUSY;
+		goto err_return;
+	}
+
+	dev_dbg(&board_dat->pdev->dev,
+		"%s create_singlethread_workqueue success\n", __func__);
+
+	retval = pci_request_regions(board_dat->pdev, KBUILD_MODNAME);
+	if (retval != 0) {
+		dev_err(&board_dat->pdev->dev,
+			"%s request_region failed\n", __func__);
+		goto err_return;
+	}
+
+	board_dat->pci_req_sts = true;
+
+	io_remap_addr = pci_iomap(board_dat->pdev, 1, 0);
+	if (io_remap_addr == 0) {
+		dev_err(&board_dat->pdev->dev,
+			"%s pci_iomap failed\n", __func__);
+		retval = -ENOMEM;
+		goto err_return;
+	}
+
+	/* calculate base address for all channels */
+	board_dat->data->io_remap_addr = io_remap_addr;
+
+	/* reset PCH SPI h/w */
+	pch_spi_reset(board_dat->data->master);
+	dev_dbg(&board_dat->pdev->dev,
+		"%s pch_spi_reset invoked successfully\n", __func__);
+
+	/* register IRQ */
+	retval = request_irq(board_dat->pdev->irq, pch_spi_handler,
+			     IRQF_SHARED, KBUILD_MODNAME, board_dat);
+	if (retval != 0) {
+		dev_err(&board_dat->pdev->dev,
+			"%s request_irq failed\n", __func__);
+		goto err_return;
+	}
+
+	dev_dbg(&board_dat->pdev->dev, "%s request_irq returned=%d\n",
+		__func__, retval);
+
+	board_dat->irq_reg_sts = true;
+	dev_dbg(&board_dat->pdev->dev, "%s data->irq_reg_sts=true\n", __func__);
+
+err_return:
+	if (retval != 0) {
+		dev_err(&board_dat->pdev->dev,
+			"%s FAIL:invoking pch_spi_free_resources\n", __func__);
+		pch_spi_free_resources(board_dat);
+	}
+
+	dev_dbg(&board_dat->pdev->dev, "%s Return=%d\n", __func__, retval);
+
+	return retval;
+}
+
+static int pch_spi_probe(struct pci_dev *pdev, const struct pci_device_id *id)
+{
+
+	struct spi_master *master;
+
+	struct pch_spi_board_data *board_dat;
+	int retval;
+
+	dev_dbg(&pdev->dev, "%s ENTRY\n", __func__);
+
+	/* allocate memory for private data */
+	board_dat = kzalloc(sizeof(struct pch_spi_board_data), GFP_KERNEL);
+	if (board_dat == NULL) {
+		dev_err(&pdev->dev,
+			" %s memory allocation for private data failed\n",
+			__func__);
+		retval = -ENOMEM;
+		goto err_kmalloc;
+	}
+
+	dev_dbg(&pdev->dev,
+		"%s memory allocation for private data success\n", __func__);
+
+	/* enable PCI device */
+	retval = pci_enable_device(pdev);
+	if (retval != 0) {
+		dev_err(&pdev->dev, "%s pci_enable_device FAILED\n", __func__);
+
+		goto err_pci_en_device;
+	}
+
+	dev_dbg(&pdev->dev, "%s pci_enable_device returned=%d\n",
+		__func__, retval);
+
+	board_dat->pdev = pdev;
+
+	/* alllocate memory for SPI master */
+	master = spi_alloc_master(&pdev->dev, sizeof(struct pch_spi_data));
+	if (master == NULL) {
+		retval = -ENOMEM;
+		dev_err(&pdev->dev, "%s Fail.\n", __func__);
+		goto err_spi_alloc_master;
+	}
+
+	dev_dbg(&pdev->dev,
+		"%s spi_alloc_master returned non NULL\n", __func__);
+
+	/* initialize members of SPI master */
+	master->bus_num = -1;
+	master->num_chipselect = PCH_MAX_CS;
+	master->setup = pch_spi_setup;
+	master->transfer = pch_spi_transfer;
+	dev_dbg(&pdev->dev,
+		"%s transfer member of SPI master initialized\n", __func__);
+
+	board_dat->data = spi_master_get_devdata(master);
+
+	board_dat->data->master = master;
+	board_dat->data->n_curnt_chip = 255;
+	board_dat->data->board_dat = board_dat;
+	board_dat->data->status = STATUS_RUNNING;
+
+	INIT_LIST_HEAD(&board_dat->data->queue);
+	spin_lock_init(&board_dat->data->lock);
+	INIT_WORK(&board_dat->data->work, pch_spi_process_messages);
+	init_waitqueue_head(&board_dat->data->wait);
+
+	/* allocate resources for PCH SPI */
+	retval = pch_spi_get_resources(board_dat);
+	if (retval) {
+		dev_err(&pdev->dev, "%s fail(retval=%d)\n", __func__, retval);
+		goto err_spi_get_resources;
+	}
+
+	dev_dbg(&pdev->dev, "%s pch_spi_get_resources returned=%d\n",
+		__func__, retval);
+
+	/* save private data in dev */
+	pci_set_drvdata(pdev, board_dat);
+	dev_dbg(&pdev->dev, "%s invoked pci_set_drvdata\n", __func__);
+
+	/* set master mode */
+	pch_spi_set_master_mode(master);
+	dev_dbg(&pdev->dev,
+		"%s invoked pch_spi_set_master_mode\n", __func__);
+
+	/* Register the controller with the SPI core. */
+	retval = spi_register_master(master);
+	if (retval != 0) {
+		dev_err(&pdev->dev,
+			"%s spi_register_master FAILED\n", __func__);
+		goto err_spi_reg_master;
+	}
+
+	dev_dbg(&pdev->dev, "%s spi_register_master returned=%d\n",
+		__func__, retval);
+
+
+	return 0;
+
+err_spi_reg_master:
+	spi_unregister_master(master);
+err_spi_get_resources:
+err_spi_alloc_master:
+	spi_master_put(master);
+	pci_disable_device(pdev);
+err_pci_en_device:
+	kfree(board_dat);
+err_kmalloc:
+	return retval;
+}
+
+static void pch_spi_remove(struct pci_dev *pdev)
+{
+	struct pch_spi_board_data *board_dat = pci_get_drvdata(pdev);
+	int count;
+
+	dev_dbg(&pdev->dev, "%s ENTRY\n", __func__);
+
+	if (!board_dat) {
+		dev_err(&pdev->dev,
+			"%s pci_get_drvdata returned NULL\n", __func__);
+		return;
+	}
+
+	/* check for any pending messages; no action is taken if the queue
+	 * is still full; but at least we tried.  Unload anyway */
+	count = 500;
+	spin_lock(&board_dat->data->lock);
+	board_dat->data->status = STATUS_EXITING;
+	while ((list_empty(&board_dat->data->queue) == 0) && --count) {
+		dev_dbg(&board_dat->pdev->dev, "%s :queue not empty\n",
+			__func__);
+		spin_unlock(&board_dat->data->lock);
+		msleep(PCH_SLEEP_TIME);
+		spin_lock(&board_dat->data->lock);
+	}
+	spin_unlock(&board_dat->data->lock);
+
+	/* Free resources allocated for PCH SPI */
+	pch_spi_free_resources(board_dat);
+
+	spi_unregister_master(board_dat->data->master);
+
+	/* free memory for private data */
+	kfree(board_dat);
+
+	pci_set_drvdata(pdev, NULL);
+
+	/* disable PCI device */
+	pci_disable_device(pdev);
+
+	dev_dbg(&pdev->dev, "%s invoked pci_disable_device\n", __func__);
+}
+
+#ifdef CONFIG_PM
+static int pch_spi_suspend(struct pci_dev *pdev, pm_message_t state)
+{
+	u8 count;
+	int retval;
+
+	struct pch_spi_board_data *board_dat = pci_get_drvdata(pdev);
+
+	dev_dbg(&pdev->dev, "%s ENTRY\n", __func__);
+
+	if (!board_dat) {
+		dev_err(&pdev->dev,
+			"%s pci_get_drvdata returned NULL\n", __func__);
+		return -EFAULT;
+	}
+
+	retval = 0;
+	board_dat->suspend_sts = true;
+
+	/* check if the current message is processed:
+	   Only after thats done the transfer will be suspended */
+	count = 255;
+	while ((--count) > 0) {
+		if (!(board_dat->data->bcurrent_msg_processing)) {
+			dev_dbg(&pdev->dev, "%s board_dat->data->bCurrent_"
+				"msg_processing = false\n", __func__);
+			break;
+		} else {
+			dev_dbg(&pdev->dev, "%s board_dat->data->bCurrent_msg_"
+				"processing = true\n", __func__);
+		}
+		msleep(PCH_SLEEP_TIME);
+	}
+
+	/* Free IRQ */
+	if (board_dat->irq_reg_sts) {
+		/* disable all interrupts */
+		pch_spi_setclr_reg(board_dat->data->master, PCH_SPCR, 0,
+				   PCH_ALL);
+		pch_spi_reset(board_dat->data->master);
+
+		free_irq(board_dat->pdev->irq, board_dat);
+
+		board_dat->irq_reg_sts = false;
+		dev_dbg(&pdev->dev,
+			"%s free_irq invoked successfully.\n", __func__);
+	}
+
+	/* save config space */
+	retval = pci_save_state(pdev);
+
+	if (retval == 0) {
+		dev_dbg(&pdev->dev, "%s pci_save_state returned=%d\n",
+			__func__, retval);
+		/* disable PM notifications */
+		pci_enable_wake(pdev, PCI_D3hot, 0);
+		dev_dbg(&pdev->dev,
+			"%s pci_enable_wake invoked successfully\n", __func__);
+		/* disable PCI device */
+		pci_disable_device(pdev);
+		dev_dbg(&pdev->dev,
+			"%s pci_disable_device invoked successfully\n",
+			__func__);
+		/* move device to D3hot  state */
+		pci_set_power_state(pdev, PCI_D3hot);
+		dev_dbg(&pdev->dev,
+			"%s pci_set_power_state invoked successfully\n",
+			__func__);
+	} else {
+		dev_err(&pdev->dev, "%s pci_save_state failed\n", __func__);
+	}
+
+	dev_dbg(&pdev->dev, "%s return=%d\n", __func__, retval);
+
+	return retval;
+}
+
+static int pch_spi_resume(struct pci_dev *pdev)
+{
+	int retval;
+
+	struct pch_spi_board_data *board = pci_get_drvdata(pdev);
+	dev_dbg(&pdev->dev, "%s ENTRY\n", __func__);
+
+	if (!board) {
+		dev_err(&pdev->dev,
+			"%s pci_get_drvdata returned NULL\n", __func__);
+		return -EFAULT;
+	}
+
+	/* move device to DO power state */
+	pci_set_power_state(pdev, PCI_D0);
+
+	/* restore state */
+	pci_restore_state(pdev);
+
+	retval = pci_enable_device(pdev);
+	if (retval < 0) {
+		dev_err(&pdev->dev,
+			"%s pci_enable_device failed\n", __func__);
+	} else {
+		/* disable PM notifications */
+		pci_enable_wake(pdev, PCI_D3hot, 0);
+
+		/* register IRQ handler */
+		if (!board->irq_reg_sts) {
+			/* register IRQ */
+			retval = request_irq(board->pdev->irq, pch_spi_handler,
+					     IRQF_SHARED, KBUILD_MODNAME,
+					     board);
+			if (retval < 0) {
+				dev_err(&pdev->dev,
+					"%s request_irq failed\n", __func__);
+				return retval;
+			}
+			board->irq_reg_sts = true;
+
+			/* reset PCH SPI h/w */
+			pch_spi_reset(board->data->master);
+			pch_spi_set_master_mode(board->data->master);
+
+			/* set suspend status to false */
+			board->suspend_sts = false;
+
+		}
+	}
+
+	dev_dbg(&pdev->dev, "%s returning=%d\n", __func__, retval);
+
+	return retval;
+}
+#else
+#define pch_spi_suspend NULL
+#define pch_spi_resume NULL
+
+#endif
+
+static struct pci_driver pch_spi_pcidev = {
+	.name = "pch_spi",
+	.id_table = pch_spi_pcidev_id,
+	.probe = pch_spi_probe,
+	.remove = pch_spi_remove,
+	.suspend = pch_spi_suspend,
+	.resume = pch_spi_resume,
+};
+
+static int __init pch_spi_init(void)
+{
+	return pci_register_driver(&pch_spi_pcidev);
+}
+module_init(pch_spi_init);
+
+static void __exit pch_spi_exit(void)
+{
+	pci_unregister_driver(&pch_spi_pcidev);
+}
+module_exit(pch_spi_exit);
+
+MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("Topcliff PCH SPI PCI Driver");