/*
   * SPI bus driver for the Topcliff PCH used by Intel SoCs

   *

   * Copyright (C) 2011 LAPIS 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>

  #include <linux/platform_device.h>

  #include <linux/dmaengine.h>
  #include <linux/pch_dma.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_ADDRESS_SIZE	0x20

  
  #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_TX_THOLD		2

  #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 SSN_LOW			0x02U

  #define SSN_HIGH		0x03U

  #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 SPSR_ORF_BIT		(1 << 3)

  #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 MASK_SPBRR_SPBR_BITS	((1 << 10) - 1)
  #define MASK_RFIC_SPCR_BITS	(0xf << SPCR_RFIC_FIELD)
  #define MASK_TFIC_SPCR_BITS	(0xf << SPCR_TFIC_FIELD)

  
  #define PCH_CLOCK_HZ		50000000
  #define PCH_MAX_SPBR		1023

  /* Definition for ML7213/ML7223/ML7831 by LAPIS Semiconductor */

  #define PCI_VENDOR_ID_ROHM		0x10DB
  #define PCI_DEVICE_ID_ML7213_SPI	0x802c

  #define PCI_DEVICE_ID_ML7223_SPI	0x800F

  #define PCI_DEVICE_ID_ML7831_SPI	0x8816

  
  /*
   * Set the number of SPI instance max
   * Intel EG20T PCH :		1ch

   * LAPIS Semiconductor ML7213 IOH :	2ch
   * LAPIS Semiconductor ML7223 IOH :	1ch
   * LAPIS Semiconductor ML7831 IOH :	1ch

  */
  #define PCH_SPI_MAX_DEV			2

  #define PCH_BUF_SIZE		4096
  #define PCH_DMA_TRANS_SIZE	12
  
  static int use_dma = 1;
  
  struct pch_spi_dma_ctrl {
  	struct dma_async_tx_descriptor	*desc_tx;
  	struct dma_async_tx_descriptor	*desc_rx;
  	struct pch_dma_slave		param_tx;
  	struct pch_dma_slave		param_rx;
  	struct dma_chan		*chan_tx;
  	struct dma_chan		*chan_rx;
  	struct scatterlist		*sg_tx_p;
  	struct scatterlist		*sg_rx_p;
  	struct scatterlist		sg_tx;
  	struct scatterlist		sg_rx;
  	int				nent;
  	void				*tx_buf_virt;
  	void				*rx_buf_virt;
  	dma_addr_t			tx_buf_dma;
  	dma_addr_t			rx_buf_dma;
  };

  /**
   * 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

   * @plat_dev:			platform_device structure
   * @ch:				SPI channel number
   * @irq_reg_sts:		Status of IRQ registration

   */
  struct pch_spi_data {
  	void __iomem *io_remap_addr;

  	unsigned long io_base_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 platform_device	*plat_dev;
  	int ch;

  	struct pch_spi_dma_ctrl dma;
  	int use_dma;

  	u8 irq_reg_sts;

  };
  
  /**
   * struct pch_spi_board_data - Holds the SPI device specific details
   * @pdev:		Pointer to the PCI device

   * @suspend_sts:	Status of suspend

   * @num:		The number of SPI device instance

   */
  struct pch_spi_board_data {
  	struct pci_dev *pdev;

  	u8 suspend_sts;

  	int num;
  };
  
  struct pch_pd_dev_save {
  	int num;
  	struct platform_device *pd_save[PCH_SPI_MAX_DEV];
  	struct pch_spi_board_data *board_dat;

  };
  
  static struct pci_device_id pch_spi_pcidev_id[] = {

  	{ PCI_VDEVICE(INTEL, PCI_DEVICE_ID_GE_SPI),    1, },
  	{ PCI_VDEVICE(ROHM, PCI_DEVICE_ID_ML7213_SPI), 2, },

  	{ PCI_VDEVICE(ROHM, PCI_DEVICE_ID_ML7223_SPI), 1, },

  	{ PCI_VDEVICE(ROHM, PCI_DEVICE_ID_ML7831_SPI), 1, },

  	{ }

  };

  /**
   * 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, (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) {

  		if ((tx_index == bpw_len) && (rx_index == tx_index)) {
  			/* disable interrupts */
  			pch_spi_setclr_reg(data->master, PCH_SPCR, 0, PCH_ALL);
  
  			/* transfer is completed;
  			   inform pch_spi_process_messages */
  			data->transfer_complete = true;
  			data->transfer_active = false;
  			wake_up(&data->wait);
  		} else {

  			dev_err(&data->master->dev,
  				"%s : Transfer is not completed", __func__);

  		}

  	}
  }

  /**
   * 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;

  	void __iomem *spsr;
  	void __iomem *io_remap_addr;
  	irqreturn_t ret = IRQ_NONE;

  	struct pch_spi_data *data = dev_id;
  	struct pch_spi_board_data *board_dat = data->board_dat;

  
  	if (board_dat->suspend_sts) {
  		dev_dbg(&board_dat->pdev->dev,
  			"%s returning due to suspend
  ", __func__);
  		return IRQ_NONE;
  	}

  	io_remap_addr = data->io_remap_addr;
  	spsr = io_remap_addr + PCH_SPSR;
  
  	reg_spsr_val = ioread32(spsr);

  	if (reg_spsr_val & SPSR_ORF_BIT) {
  		dev_err(&board_dat->pdev->dev, "%s Over run error
  ", __func__);
  		if (data->current_msg->complete != 0) {
  			data->transfer_complete = true;
  			data->current_msg->status = -EIO;
  			data->current_msg->complete(data->current_msg->context);
  			data->bcurrent_msg_processing = false;
  			data->current_msg = NULL;
  			data->cur_trans = NULL;
  		}
  	}
  
  	if (data->use_dma)
  		return IRQ_NONE;

  	/* 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
  ",
  		__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
  ",
  		__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
  ", __func__);
  	}

  	if ((pspi->bits_per_word != 8) && (pspi->bits_per_word != 16)) {

  		dev_err(&pspi->dev, "%s Invalid bits per word
  ", __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
  ", __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
  ", __func__);
  		retval = -EINVAL;
  		goto err_out;
  	}

  	if (unlikely(pspi->max_speed_hz == 0)) {
  		dev_err(&pspi->dev, "%s pch_spi_tranfer maxspeed=%d
  ",
  			__func__, pspi->max_speed_hz);

  		retval = -EINVAL;
  		goto err_out;
  	}
  
  	dev_dbg(&pspi->dev, "%s Transfer List not empty. "
  		"Transfer Speed is set.
  ", __func__);

  	spin_lock_irqsave(&data->lock, flags);

  	/* 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
  ", __func__);
  			retval = -EINVAL;

  			goto err_return_spinlock;

  		}

  		if (!transfer->len) {

  			dev_err(&pspi->dev, "%s Transfer length invalid
  ",
  				__func__);
  			retval = -EINVAL;

  			goto err_return_spinlock;

  		}
  
  		dev_dbg(&pspi->dev, "%s Tx/Rx buffer valid. Transfer length"
  			" valid
  ", __func__);

  		/* if baud rate has 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
  ", __func__);

  				goto err_return_spinlock;

  			}
  		}
  	}

  	spin_unlock_irqrestore(&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.
  ", __func__);
  		retval = -ESHUTDOWN;

  		goto err_out;

  	}
  
  	/* If suspended ,return -EINVAL */
  	if (data->board_dat->suspend_sts) {

  		dev_err(&pspi->dev, "%s suspend; returning EINVAL
  ", __func__);

  		retval = -EINVAL;

  		goto err_out;

  	}
  
  	/* set status of message */
  	pmsg->actual_length = 0;

  	dev_dbg(&pspi->dev, "%s - pmsg->status =%d
  ", __func__, pmsg->status);
  
  	pmsg->status = -EINPROGRESS;

  	spin_lock_irqsave(&data->lock, flags);

  	/* add message to queue */
  	list_add_tail(&pmsg->queue, &data->queue);

  	spin_unlock_irqrestore(&data->lock, flags);

  	dev_dbg(&pspi->dev, "%s - Invoked list_add_tail
  ", __func__);
  
  	/* schedule work queue to run */
  	queue_work(data->wk, &data->work);

  	dev_dbg(&pspi->dev, "%s - Invoked queue work
  ", __func__);
  
  	retval = 0;

  err_out:
  	dev_dbg(&pspi->dev, "%s RETURN=%d
  ", __func__, retval);
  	return retval;

  err_return_spinlock:
  	dev_dbg(&pspi->dev, "%s RETURN=%d
  ", __func__, retval);
  	spin_unlock_irqrestore(&data->lock, flags);
  	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
  ", __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
  ", __func__);
  	pch_spi_setup_transfer(pspi);
  }

  static void pch_spi_set_tx(struct pch_spi_data *data, int *bpw)

  {

  	int size;
  	u32 n_writes;
  	int j;
  	struct spi_message *pmsg;
  	const u8 *tx_buf;
  	const u16 *tx_sbuf;

  	/* set baud rate if needed */
  	if (data->cur_trans->speed_hz) {

  		dev_dbg(&data->master->dev, "%s:setting baud rate
  ", __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
  ", __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
  ", __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, "
  %s:Pulling down SSN low - writing "

  		"0x2 to SSNXCR
  ", __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
  ", __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
  ", __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
  ", __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
  ", __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
  ",
  			__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, set threshold, enable SPI */
  	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 |
  				   SPCR_FIE_BIT | SPCR_RFIE_BIT |
  				   SPCR_ORIE_BIT | SPCR_SPE_BIT,
  				   MASK_RFIC_SPCR_BITS | PCH_ALL);
  	else

  		/* set receive threshold to maximum */

  		pch_spi_setclr_reg(data->master, PCH_SPCR,

  				   PCH_RX_THOLD_MAX << SPCR_RFIC_FIELD |
  				   SPCR_FIE_BIT | SPCR_ORIE_BIT |
  				   SPCR_SPE_BIT,
  				   MASK_RFIC_SPCR_BITS | PCH_ALL);

  
  	/* Wait until the transfer completes; go to sleep after
  				 initiating the transfer. */
  	dev_dbg(&data->master->dev,
  		"%s:waiting for transfer to get over
  ", __func__);
  
  	wait_event_interruptible(data->wait, data->transfer_complete);

  	/* clear all interrupts */
  	pch_spi_writereg(data->master, PCH_SPSR,

  			 pch_spi_readreg(data->master, PCH_SPSR));

  	/* Disable interrupts and SPI transfer */
  	pch_spi_setclr_reg(data->master, PCH_SPCR, 0, PCH_ALL | SPCR_SPE_BIT);
  	/* clear FIFO */
  	pch_spi_clear_fifo(data->master);

  }
  
  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_copy_rx_data_for_dma(struct pch_spi_data *data, int bpw)
  {
  	int j;
  	u8 *rx_buf;
  	u16 *rx_sbuf;
  	const u8 *rx_dma_buf;
  	const u16 *rx_dma_sbuf;
  
  	/* copy Rx Data */
  	if (!data->cur_trans->rx_buf)
  		return;
  
  	if (bpw == 8) {
  		rx_buf = data->cur_trans->rx_buf;
  		rx_dma_buf = data->dma.rx_buf_virt;
  		for (j = 0; j < data->bpw_len; j++)
  			*rx_buf++ = *rx_dma_buf++ & 0xFF;
  	} else {
  		rx_sbuf = data->cur_trans->rx_buf;
  		rx_dma_sbuf = data->dma.rx_buf_virt;
  		for (j = 0; j < data->bpw_len; j++)
  			*rx_sbuf++ = *rx_dma_sbuf++;
  	}
  }

  static int pch_spi_start_transfer(struct pch_spi_data *data)

  {
  	struct pch_spi_dma_ctrl *dma;
  	unsigned long flags;

  	int rtn;

  
  	dma = &data->dma;
  
  	spin_lock_irqsave(&data->lock, flags);
  
  	/* disable interrupts, SPI set enable */
  	pch_spi_setclr_reg(data->master, PCH_SPCR, SPCR_SPE_BIT, PCH_ALL);
  
  	spin_unlock_irqrestore(&data->lock, flags);
  
  	/* Wait until the transfer completes; go to sleep after
  				 initiating the transfer. */
  	dev_dbg(&data->master->dev,
  		"%s:waiting for transfer to get over
  ", __func__);

  	rtn = wait_event_interruptible_timeout(data->wait,
  					       data->transfer_complete,
  					       msecs_to_jiffies(2 * HZ));

  
  	dma_sync_sg_for_cpu(&data->master->dev, dma->sg_rx_p, dma->nent,
  			    DMA_FROM_DEVICE);

  
  	dma_sync_sg_for_cpu(&data->master->dev, dma->sg_tx_p, dma->nent,
  			    DMA_FROM_DEVICE);
  	memset(data->dma.tx_buf_virt, 0, PAGE_SIZE);

  	async_tx_ack(dma->desc_rx);
  	async_tx_ack(dma->desc_tx);
  	kfree(dma->sg_tx_p);
  	kfree(dma->sg_rx_p);
  
  	spin_lock_irqsave(&data->lock, flags);

  
  	/* clear fifo threshold, disable interrupts, disable SPI transfer */
  	pch_spi_setclr_reg(data->master, PCH_SPCR, 0,
  			   MASK_RFIC_SPCR_BITS | MASK_TFIC_SPCR_BITS | PCH_ALL |
  			   SPCR_SPE_BIT);
  	/* clear all interrupts */
  	pch_spi_writereg(data->master, PCH_SPSR,
  			 pch_spi_readreg(data->master, PCH_SPSR));
  	/* clear FIFO */
  	pch_spi_clear_fifo(data->master);
  
  	spin_unlock_irqrestore(&data->lock, flags);

  
  	return rtn;

  }
  
  static void pch_dma_rx_complete(void *arg)
  {
  	struct pch_spi_data *data = arg;
  
  	/* transfer is completed;inform pch_spi_process_messages_dma */
  	data->transfer_complete = true;
  	wake_up_interruptible(&data->wait);
  }
  
  static bool pch_spi_filter(struct dma_chan *chan, void *slave)
  {
  	struct pch_dma_slave *param = slave;
  
  	if ((chan->chan_id == param->chan_id) &&
  	    (param->dma_dev == chan->device->dev)) {
  		chan->private = param;
  		return true;
  	} else {
  		return false;
  	}
  }
  
  static void pch_spi_request_dma(struct pch_spi_data *data, int bpw)
  {
  	dma_cap_mask_t mask;
  	struct dma_chan *chan;
  	struct pci_dev *dma_dev;
  	struct pch_dma_slave *param;
  	struct pch_spi_dma_ctrl *dma;
  	unsigned int width;
  
  	if (bpw == 8)
  		width = PCH_DMA_WIDTH_1_BYTE;
  	else
  		width = PCH_DMA_WIDTH_2_BYTES;
  
  	dma = &data->dma;
  	dma_cap_zero(mask);
  	dma_cap_set(DMA_SLAVE, mask);
  
  	/* Get DMA's dev information */
  	dma_dev = pci_get_bus_and_slot(2, PCI_DEVFN(12, 0));
  
  	/* Set Tx DMA */
  	param = &dma->param_tx;
  	param->dma_dev = &dma_dev->dev;
  	param->chan_id = data->master->bus_num * 2; /* Tx = 0, 2 */
  	param->tx_reg = data->io_base_addr + PCH_SPDWR;
  	param->width = width;
  	chan = dma_request_channel(mask, pch_spi_filter, param);
  	if (!chan) {
  		dev_err(&data->master->dev,
  			"ERROR: dma_request_channel FAILS(Tx)
  ");
  		data->use_dma = 0;
  		return;
  	}
  	dma->chan_tx = chan;
  
  	/* Set Rx DMA */
  	param = &dma->param_rx;
  	param->dma_dev = &dma_dev->dev;
  	param->chan_id = data->master->bus_num * 2 + 1; /* Rx = Tx + 1 */
  	param->rx_reg = data->io_base_addr + PCH_SPDRR;
  	param->width = width;
  	chan = dma_request_channel(mask, pch_spi_filter, param);
  	if (!chan) {
  		dev_err(&data->master->dev,
  			"ERROR: dma_request_channel FAILS(Rx)
  ");
  		dma_release_channel(dma->chan_tx);
  		dma->chan_tx = NULL;
  		data->use_dma = 0;
  		return;
  	}
  	dma->chan_rx = chan;
  }
  
  static void pch_spi_release_dma(struct pch_spi_data *data)
  {
  	struct pch_spi_dma_ctrl *dma;
  
  	dma = &data->dma;
  	if (dma->chan_tx) {
  		dma_release_channel(dma->chan_tx);
  		dma->chan_tx = NULL;
  	}
  	if (dma->chan_rx) {
  		dma_release_channel(dma->chan_rx);
  		dma->chan_rx = NULL;
  	}
  	return;
  }
  
  static void pch_spi_handle_dma(struct pch_spi_data *data, int *bpw)
  {
  	const u8 *tx_buf;
  	const u16 *tx_sbuf;
  	u8 *tx_dma_buf;
  	u16 *tx_dma_sbuf;
  	struct scatterlist *sg;
  	struct dma_async_tx_descriptor *desc_tx;
  	struct dma_async_tx_descriptor *desc_rx;
  	int num;
  	int i;
  	int size;
  	int rem;
  	unsigned long flags;
  	struct pch_spi_dma_ctrl *dma;
  
  	dma = &data->dma;
  
  	/* set baud rate if needed */
  	if (data->cur_trans->speed_hz) {
  		dev_dbg(&data->master->dev, "%s:setting baud rate
  ", __func__);
  		spin_lock_irqsave(&data->lock, flags);
  		pch_spi_set_baud_rate(data->master, data->cur_trans->speed_hz);
  		spin_unlock_irqrestore(&data->lock, flags);
  	}
  
  	/* 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
  ", __func__);
  		spin_lock_irqsave(&data->lock, flags);
  		pch_spi_set_bits_per_word(data->master,
  					  data->cur_trans->bits_per_word);
  		spin_unlock_irqrestore(&data->lock, flags);
  		*bpw = data->cur_trans->bits_per_word;
  	} else {
  		*bpw = data->current_msg->spi->bits_per_word;
  	}
  	data->bpw_len = data->cur_trans->len / (*bpw / 8);
  
  	/* copy Tx Data */
  	if (data->cur_trans->tx_buf != NULL) {
  		if (*bpw == 8) {
  			tx_buf = data->cur_trans->tx_buf;
  			tx_dma_buf = dma->tx_buf_virt;
  			for (i = 0; i < data->bpw_len; i++)
  				*tx_dma_buf++ = *tx_buf++;
  		} else {
  			tx_sbuf = data->cur_trans->tx_buf;
  			tx_dma_sbuf = dma->tx_buf_virt;
  			for (i = 0; i < data->bpw_len; i++)
  				*tx_dma_sbuf++ = *tx_sbuf++;
  		}
  	}
  	if (data->bpw_len > PCH_DMA_TRANS_SIZE) {
  		num = data->bpw_len / PCH_DMA_TRANS_SIZE + 1;
  		size = PCH_DMA_TRANS_SIZE;
  		rem = data->bpw_len % PCH_DMA_TRANS_SIZE;
  	} else {
  		num = 1;
  		size = data->bpw_len;
  		rem = data->bpw_len;
  	}
  	dev_dbg(&data->master->dev, "%s num=%d size=%d rem=%d
  ",
  		__func__, num, size, rem);
  	spin_lock_irqsave(&data->lock, flags);
  
  	/* set receive fifo threshold and transmit fifo threshold */
  	pch_spi_setclr_reg(data->master, PCH_SPCR,
  			   ((size - 1) << SPCR_RFIC_FIELD) |

  			   (PCH_TX_THOLD << SPCR_TFIC_FIELD),

  			   MASK_RFIC_SPCR_BITS | MASK_TFIC_SPCR_BITS);
  
  	spin_unlock_irqrestore(&data->lock, flags);
  
  	/* RX */
  	dma->sg_rx_p = kzalloc(sizeof(struct scatterlist)*num, GFP_ATOMIC);
  	sg_init_table(dma->sg_rx_p, num); /* Initialize SG table */
  	/* offset, length setting */
  	sg = dma->sg_rx_p;
  	for (i = 0; i < num; i++, sg++) {

  		if (i == (num - 2)) {
  			sg->offset = size * i;
  			sg->offset = sg->offset * (*bpw / 8);

  			sg_set_page(sg, virt_to_page(dma->rx_buf_virt), rem,
  				    sg->offset);
  			sg_dma_len(sg) = rem;

  		} else if (i == (num - 1)) {
  			sg->offset = size * (i - 1) + rem;
  			sg->offset = sg->offset * (*bpw / 8);
  			sg_set_page(sg, virt_to_page(dma->rx_buf_virt), size,
  				    sg->offset);
  			sg_dma_len(sg) = size;

  		} else {

  			sg->offset = size * i;

  			sg->offset = sg->offset * (*bpw / 8);
  			sg_set_page(sg, virt_to_page(dma->rx_buf_virt), size,
  				    sg->offset);
  			sg_dma_len(sg) = size;
  		}
  		sg_dma_address(sg) = dma->rx_buf_dma + sg->offset;
  	}
  	sg = dma->sg_rx_p;
  	desc_rx = dma->chan_rx->device->device_prep_slave_sg(dma->chan_rx, sg,
  					num, DMA_FROM_DEVICE,
  					DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
  	if (!desc_rx) {
  		dev_err(&data->master->dev, "%s:device_prep_slave_sg Failed
  ",
  			__func__);
  		return;
  	}
  	dma_sync_sg_for_device(&data->master->dev, sg, num, DMA_FROM_DEVICE);
  	desc_rx->callback = pch_dma_rx_complete;
  	desc_rx->callback_param = data;
  	dma->nent = num;
  	dma->desc_rx = desc_rx;
  
  	/* TX */

  	if (data->bpw_len > PCH_DMA_TRANS_SIZE) {
  		num = data->bpw_len / PCH_DMA_TRANS_SIZE;
  		size = PCH_DMA_TRANS_SIZE;
  		rem = 16;
  	} else {
  		num = 1;
  		size = data->bpw_len;
  		rem = data->bpw_len;
  	}

  	dma->sg_tx_p = kzalloc(sizeof(struct scatterlist)*num, GFP_ATOMIC);
  	sg_init_table(dma->sg_tx_p, num); /* Initialize SG table */
  	/* offset, length setting */
  	sg = dma->sg_tx_p;
  	for (i = 0; i < num; i++, sg++) {
  		if (i == 0) {
  			sg->offset = 0;
  			sg_set_page(sg, virt_to_page(dma->tx_buf_virt), rem,
  				    sg->offset);
  			sg_dma_len(sg) = rem;
  		} else {
  			sg->offset = rem + size * (i - 1);
  			sg->offset = sg->offset * (*bpw / 8);
  			sg_set_page(sg, virt_to_page(dma->tx_buf_virt), size,
  				    sg->offset);
  			sg_dma_len(sg) = size;
  		}
  		sg_dma_address(sg) = dma->tx_buf_dma + sg->offset;
  	}
  	sg = dma->sg_tx_p;
  	desc_tx = dma->chan_tx->device->device_prep_slave_sg(dma->chan_tx,
  					sg, num, DMA_TO_DEVICE,
  					DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
  	if (!desc_tx) {
  		dev_err(&data->master->dev, "%s:device_prep_slave_sg Failed
  ",
  			__func__);
  		return;
  	}
  	dma_sync_sg_for_device(&data->master->dev, sg, num, DMA_TO_DEVICE);
  	desc_tx->callback = NULL;
  	desc_tx->callback_param = data;
  	dma->nent = num;
  	dma->desc_tx = desc_tx;
  
  	dev_dbg(&data->master->dev, "
  %s:Pulling down SSN low - writing "
  		"0x2 to SSNXCR
  ", __func__);
  
  	spin_lock_irqsave(&data->lock, flags);
  	pch_spi_writereg(data->master, PCH_SSNXCR, SSN_LOW);
  	desc_rx->tx_submit(desc_rx);
  	desc_tx->tx_submit(desc_tx);
  	spin_unlock_irqrestore(&data->lock, flags);
  
  	/* reset transfer complete flag */
  	data->transfer_complete = false;
  }

  
  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
  ", __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
  ", __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
  ", __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);

  	if (data->use_dma)
  		pch_spi_request_dma(data,
  				    data->current_msg->spi->bits_per_word);

  	pch_spi_writereg(data->master, PCH_SSNXCR, SSN_NO_CONTROL);

  	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
  ", __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
  ", __func__);

  		}

  		spin_unlock(&data->lock);

  		if (data->use_dma) {
  			pch_spi_handle_dma(data, &bpw);

  			if (!pch_spi_start_transfer(data))
  				goto out;

  			pch_spi_copy_rx_data_for_dma(data, bpw);
  		} else {
  			pch_spi_set_tx(data, &bpw);
  			pch_spi_set_ir(data);
  			pch_spi_copy_rx_data(data, bpw);
  			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
  ",
  			__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
  ", __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);

  		}
  
  		spin_unlock(&data->lock);

  	} while (data->cur_trans != NULL);

  out:

  	pch_spi_writereg(data->master, PCH_SSNXCR, SSN_HIGH);

  	if (data->use_dma)
  		pch_spi_release_dma(data);

  }

  static void pch_spi_free_resources(struct pch_spi_board_data *board_dat,
  				   struct pch_spi_data *data)

  {
  	dev_dbg(&board_dat->pdev->dev, "%s ENTRY
  ", __func__);
  
  	/* free workqueue */

  	if (data->wk != NULL) {
  		destroy_workqueue(data->wk);
  		data->wk = NULL;

  		dev_dbg(&board_dat->pdev->dev,
  			"%s destroy_workqueue invoked successfully
  ",
  			__func__);
  	}

  }

  static int pch_spi_get_resources(struct pch_spi_board_data *board_dat,
  				 struct pch_spi_data *data)

  {

  	int retval = 0;

  	dev_dbg(&board_dat->pdev->dev, "%s ENTRY
  ", __func__);

  	/* create workqueue */

  	data->wk = create_singlethread_workqueue(KBUILD_MODNAME);
  	if (!data->wk) {

  		dev_err(&board_dat->pdev->dev,
  			"%s create_singlet hread_workqueue failed
  ", __func__);
  		retval = -EBUSY;
  		goto err_return;
  	}

  	/* reset PCH SPI h/w */

  	pch_spi_reset(data->master);

  	dev_dbg(&board_dat->pdev->dev,
  		"%s pch_spi_reset invoked successfully
  ", __func__);

  	dev_dbg(&board_dat->pdev->dev, "%s data->irq_reg_sts=true
  ", __func__);

  
  err_return:
  	if (retval != 0) {
  		dev_err(&board_dat->pdev->dev,
  			"%s FAIL:invoking pch_spi_free_resources
  ", __func__);

  		pch_spi_free_resources(board_dat, data);

  	}
  
  	dev_dbg(&board_dat->pdev->dev, "%s Return=%d
  ", __func__, retval);
  
  	return retval;
  }

  static void pch_free_dma_buf(struct pch_spi_board_data *board_dat,
  			     struct pch_spi_data *data)
  {
  	struct pch_spi_dma_ctrl *dma;
  
  	dma = &data->dma;
  	if (dma->tx_buf_dma)
  		dma_free_coherent(&board_dat->pdev->dev, PCH_BUF_SIZE,
  				  dma->tx_buf_virt, dma->tx_buf_dma);
  	if (dma->rx_buf_dma)
  		dma_free_coherent(&board_dat->pdev->dev, PCH_BUF_SIZE,
  				  dma->rx_buf_virt, dma->rx_buf_dma);
  	return;
  }
  
  static void pch_alloc_dma_buf(struct pch_spi_board_data *board_dat,
  			      struct pch_spi_data *data)
  {
  	struct pch_spi_dma_ctrl *dma;
  
  	dma = &data->dma;
  	/* Get Consistent memory for Tx DMA */
  	dma->tx_buf_virt = dma_alloc_coherent(&board_dat->pdev->dev,
  				PCH_BUF_SIZE, &dma->tx_buf_dma, GFP_KERNEL);
  	/* Get Consistent memory for Rx DMA */
  	dma->rx_buf_virt = dma_alloc_coherent(&board_dat->pdev->dev,
  				PCH_BUF_SIZE, &dma->rx_buf_dma, GFP_KERNEL);
  }

  static int __devinit pch_spi_pd_probe(struct platform_device *plat_dev)

  {

  	int ret;

  	struct spi_master *master;

  	struct pch_spi_board_data *board_dat = dev_get_platdata(&plat_dev->dev);
  	struct pch_spi_data *data;

  	dev_dbg(&plat_dev->dev, "%s:debug
  ", __func__);

  	master = spi_alloc_master(&board_dat->pdev->dev,
  				  sizeof(struct pch_spi_data));
  	if (!master) {
  		dev_err(&plat_dev->dev, "spi_alloc_master[%d] failed.
  ",
  			plat_dev->id);
  		return -ENOMEM;

  	}

  	data = spi_master_get_devdata(master);
  	data->master = master;

  	platform_set_drvdata(plat_dev, data);

  	/* baseaddress + address offset) */
  	data->io_base_addr = pci_resource_start(board_dat->pdev, 1) +
  					 PCH_ADDRESS_SIZE * plat_dev->id;

  	data->io_remap_addr = pci_iomap(board_dat->pdev, 1, 0) +

  					 PCH_ADDRESS_SIZE * plat_dev->id;

  	if (!data->io_remap_addr) {
  		dev_err(&plat_dev->dev, "%s pci_iomap failed
  ", __func__);
  		ret = -ENOMEM;
  		goto err_pci_iomap;

  	}

  	dev_dbg(&plat_dev->dev, "[ch%d] remap_addr=%p
  ",
  		plat_dev->id, data->io_remap_addr);

  
  	/* 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;

  	data->board_dat = board_dat;
  	data->plat_dev = plat_dev;
  	data->n_curnt_chip = 255;
  	data->status = STATUS_RUNNING;
  	data->ch = plat_dev->id;

  	data->use_dma = use_dma;

  	INIT_LIST_HEAD(&data->queue);
  	spin_lock_init(&data->lock);
  	INIT_WORK(&data->work, pch_spi_process_messages);
  	init_waitqueue_head(&data->wait);

  	ret = pch_spi_get_resources(board_dat, data);
  	if (ret) {
  		dev_err(&plat_dev->dev, "%s fail(retval=%d)
  ", __func__, ret);

  		goto err_spi_get_resources;
  	}

  	ret = request_irq(board_dat->pdev->irq, pch_spi_handler,
  			  IRQF_SHARED, KBUILD_MODNAME, data);
  	if (ret) {
  		dev_err(&plat_dev->dev,
  			"%s request_irq failed
  ", __func__);
  		goto err_request_irq;
  	}
  	data->irq_reg_sts = true;

  	pch_spi_set_master_mode(master);

  	ret = spi_register_master(master);
  	if (ret != 0) {
  		dev_err(&plat_dev->dev,

  			"%s spi_register_master FAILED
  ", __func__);

  		goto err_spi_register_master;

  	}

  	if (use_dma) {
  		dev_info(&plat_dev->dev, "Use DMA for data transfers
  ");
  		pch_alloc_dma_buf(board_dat, data);
  	}

  	return 0;

  err_spi_register_master:
  	free_irq(board_dat->pdev->irq, board_dat);
  err_request_irq:
  	pch_spi_free_resources(board_dat, data);

  err_spi_get_resources:

  	pci_iounmap(board_dat->pdev, data->io_remap_addr);
  err_pci_iomap:

  	spi_master_put(master);

  
  	return ret;

  }

  static int __devexit pch_spi_pd_remove(struct platform_device *plat_dev)

  {

  	struct pch_spi_board_data *board_dat = dev_get_platdata(&plat_dev->dev);
  	struct pch_spi_data *data = platform_get_drvdata(plat_dev);

  	int count;

  	unsigned long flags;

  	dev_dbg(&plat_dev->dev, "%s:[ch%d] irq=%d
  ",
  		__func__, plat_dev->id, board_dat->pdev->irq);

  
  	if (use_dma)
  		pch_free_dma_buf(board_dat, data);

  	/* 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_irqsave(&data->lock, flags);

  	data->status = STATUS_EXITING;
  	while ((list_empty(&data->queue) == 0) && --count) {

  		dev_dbg(&board_dat->pdev->dev, "%s :queue not empty
  ",
  			__func__);

  		spin_unlock_irqrestore(&data->lock, flags);

  		msleep(PCH_SLEEP_TIME);

  		spin_lock_irqsave(&data->lock, flags);

  	}

  	spin_unlock_irqrestore(&data->lock, flags);

  	pch_spi_free_resources(board_dat, data);
  	/* disable interrupts & free IRQ */
  	if (data->irq_reg_sts) {
  		/* disable interrupts */
  		pch_spi_setclr_reg(data->master, PCH_SPCR, 0, PCH_ALL);
  		data->irq_reg_sts = false;
  		free_irq(board_dat->pdev->irq, data);
  	}

  	pci_iounmap(board_dat->pdev, data->io_remap_addr);
  	spi_unregister_master(data->master);
  	spi_master_put(data->master);
  	platform_set_drvdata(plat_dev, NULL);

  	return 0;

  }

  #ifdef CONFIG_PM

  static int pch_spi_pd_suspend(struct platform_device *pd_dev,
  			      pm_message_t state)

  {
  	u8 count;

  	struct pch_spi_board_data *board_dat = dev_get_platdata(&pd_dev->dev);
  	struct pch_spi_data *data = platform_get_drvdata(pd_dev);

  	dev_dbg(&pd_dev->dev, "%s ENTRY
  ", __func__);

  
  	if (!board_dat) {

  		dev_err(&pd_dev->dev,

  			"%s pci_get_drvdata returned NULL
  ", __func__);
  		return -EFAULT;
  	}

  	/* check if the current message is processed:
  	   Only after thats done the transfer will be suspended */
  	count = 255;

  	while ((--count) > 0) {
  		if (!(data->bcurrent_msg_processing))

  			break;

  		msleep(PCH_SLEEP_TIME);
  	}
  
  	/* Free IRQ */

  	if (data->irq_reg_sts) {

  		/* disable all interrupts */

  		pch_spi_setclr_reg(data->master, PCH_SPCR, 0, PCH_ALL);
  		pch_spi_reset(data->master);
  		free_irq(board_dat->pdev->irq, data);

  		data->irq_reg_sts = false;
  		dev_dbg(&pd_dev->dev,

  			"%s free_irq invoked successfully.
  ", __func__);
  	}

  	return 0;
  }
  
  static int pch_spi_pd_resume(struct platform_device *pd_dev)
  {
  	struct pch_spi_board_data *board_dat = dev_get_platdata(&pd_dev->dev);
  	struct pch_spi_data *data = platform_get_drvdata(pd_dev);
  	int retval;
  
  	if (!board_dat) {
  		dev_err(&pd_dev->dev,
  			"%s pci_get_drvdata returned NULL
  ", __func__);
  		return -EFAULT;
  	}
  
  	if (!data->irq_reg_sts) {
  		/* register IRQ */
  		retval = request_irq(board_dat->pdev->irq, pch_spi_handler,
  				     IRQF_SHARED, KBUILD_MODNAME, data);
  		if (retval < 0) {
  			dev_err(&pd_dev->dev,
  				"%s request_irq failed
  ", __func__);
  			return retval;
  		}
  
  		/* reset PCH SPI h/w */
  		pch_spi_reset(data->master);
  		pch_spi_set_master_mode(data->master);
  		data->irq_reg_sts = true;
  	}
  	return 0;
  }
  #else
  #define pch_spi_pd_suspend NULL
  #define pch_spi_pd_resume NULL
  #endif
  
  static struct platform_driver pch_spi_pd_driver = {
  	.driver = {
  		.name = "pch-spi",
  		.owner = THIS_MODULE,
  	},
  	.probe = pch_spi_pd_probe,
  	.remove = __devexit_p(pch_spi_pd_remove),
  	.suspend = pch_spi_pd_suspend,
  	.resume = pch_spi_pd_resume
  };
  
  static int __devinit pch_spi_probe(struct pci_dev *pdev,
  				   const struct pci_device_id *id)
  {
  	struct pch_spi_board_data *board_dat;
  	struct platform_device *pd_dev = NULL;
  	int retval;
  	int i;
  	struct pch_pd_dev_save *pd_dev_save;
  
  	pd_dev_save = kzalloc(sizeof(struct pch_pd_dev_save), GFP_KERNEL);
  	if (!pd_dev_save) {
  		dev_err(&pdev->dev, "%s Can't allocate pd_dev_sav
  ", __func__);
  		return -ENOMEM;
  	}
  
  	board_dat = kzalloc(sizeof(struct pch_spi_board_data), GFP_KERNEL);
  	if (!board_dat) {
  		dev_err(&pdev->dev, "%s Can't allocate board_dat
  ", __func__);
  		retval = -ENOMEM;
  		goto err_no_mem;
  	}
  
  	retval = pci_request_regions(pdev, KBUILD_MODNAME);
  	if (retval) {
  		dev_err(&pdev->dev, "%s request_region failed
  ", __func__);
  		goto pci_request_regions;
  	}
  
  	board_dat->pdev = pdev;
  	board_dat->num = id->driver_data;
  	pd_dev_save->num = id->driver_data;
  	pd_dev_save->board_dat = board_dat;
  
  	retval = pci_enable_device(pdev);
  	if (retval) {
  		dev_err(&pdev->dev, "%s pci_enable_device failed
  ", __func__);
  		goto pci_enable_device;
  	}
  
  	for (i = 0; i < board_dat->num; i++) {
  		pd_dev = platform_device_alloc("pch-spi", i);
  		if (!pd_dev) {
  			dev_err(&pdev->dev, "platform_device_alloc failed
  ");
  			goto err_platform_device;
  		}
  		pd_dev_save->pd_save[i] = pd_dev;
  		pd_dev->dev.parent = &pdev->dev;
  
  		retval = platform_device_add_data(pd_dev, board_dat,
  						  sizeof(*board_dat));
  		if (retval) {
  			dev_err(&pdev->dev,
  				"platform_device_add_data failed
  ");
  			platform_device_put(pd_dev);
  			goto err_platform_device;
  		}
  
  		retval = platform_device_add(pd_dev);
  		if (retval) {
  			dev_err(&pdev->dev, "platform_device_add failed
  ");
  			platform_device_put(pd_dev);
  			goto err_platform_device;
  		}
  	}
  
  	pci_set_drvdata(pdev, pd_dev_save);
  
  	return 0;
  
  err_platform_device:
  	pci_disable_device(pdev);
  pci_enable_device:
  	pci_release_regions(pdev);
  pci_request_regions:
  	kfree(board_dat);
  err_no_mem:
  	kfree(pd_dev_save);
  
  	return retval;
  }
  
  static void __devexit pch_spi_remove(struct pci_dev *pdev)
  {
  	int i;
  	struct pch_pd_dev_save *pd_dev_save = pci_get_drvdata(pdev);
  
  	dev_dbg(&pdev->dev, "%s ENTRY:pdev=%p
  ", __func__, pdev);
  
  	for (i = 0; i < pd_dev_save->num; i++)
  		platform_device_unregister(pd_dev_save->pd_save[i]);
  
  	pci_disable_device(pdev);
  	pci_release_regions(pdev);
  	kfree(pd_dev_save->board_dat);
  	kfree(pd_dev_save);
  }
  
  #ifdef CONFIG_PM
  static int pch_spi_suspend(struct pci_dev *pdev, pm_message_t state)
  {
  	int retval;
  	struct pch_pd_dev_save *pd_dev_save = pci_get_drvdata(pdev);
  
  	dev_dbg(&pdev->dev, "%s ENTRY
  ", __func__);
  
  	pd_dev_save->board_dat->suspend_sts = true;

  	/* save config space */
  	retval = pci_save_state(pdev);

  	if (retval == 0) {

  		pci_enable_wake(pdev, PCI_D3hot, 0);

  		pci_disable_device(pdev);

  		pci_set_power_state(pdev, PCI_D3hot);

  	} else {
  		dev_err(&pdev->dev, "%s pci_save_state failed
  ", __func__);
  	}

  	return retval;
  }
  
  static int pch_spi_resume(struct pci_dev *pdev)
  {
  	int retval;

  	struct pch_pd_dev_save *pd_dev_save = pci_get_drvdata(pdev);

  	dev_dbg(&pdev->dev, "%s ENTRY
  ", __func__);

  	pci_set_power_state(pdev, PCI_D0);

  	pci_restore_state(pdev);
  
  	retval = pci_enable_device(pdev);
  	if (retval < 0) {
  		dev_err(&pdev->dev,
  			"%s pci_enable_device failed
  ", __func__);
  	} else {

  		pci_enable_wake(pdev, PCI_D3hot, 0);

  		/* set suspend status to false */
  		pd_dev_save->board_dat->suspend_sts = false;

  	}

  	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)
  {

  	int ret;
  	ret = platform_driver_register(&pch_spi_pd_driver);
  	if (ret)
  		return ret;
  
  	ret = pci_register_driver(&pch_spi_pcidev);
  	if (ret)
  		return ret;
  
  	return 0;

  }
  module_init(pch_spi_init);

  static void __exit pch_spi_exit(void)
  {
  	pci_unregister_driver(&pch_spi_pcidev);

  	platform_driver_unregister(&pch_spi_pd_driver);

  }
  module_exit(pch_spi_exit);

  module_param(use_dma, int, 0644);
  MODULE_PARM_DESC(use_dma,
  		 "to use DMA for data transfers pass 1 else 0; default 1");

  MODULE_LICENSE("GPL");

  MODULE_DESCRIPTION("Intel EG20T PCH/LAPIS Semiconductor ML7xxx IOH SPI Driver");