/*
   *  Promise PATA TX2/TX4/TX2000/133 IDE driver for pdc20268 to pdc20277.
   *
   *  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; either version
   *  2 of the License, or (at your option) any later version.
   *
   *  Ported to libata by:
   *  Albert Lee <albertcc@tw.ibm.com> IBM Corporation
   *
   *  Copyright (C) 1998-2002		Andre Hedrick <andre@linux-ide.org>
   *  Portions Copyright (C) 1999 Promise Technology, Inc.
   *
   *  Author: Frank Tiernan (frankt@promise.com)
   *  Released under terms of General Public License
   *
   *
   *  libata documentation is available via 'make {ps|pdf}docs',
   *  as Documentation/DocBook/libata.*
   *
   *  Hardware information only available under NDA.
   *
   */
  #include <linux/kernel.h>
  #include <linux/module.h>
  #include <linux/pci.h>
  #include <linux/blkdev.h>
  #include <linux/delay.h>
  #include <linux/device.h>
  #include <scsi/scsi.h>
  #include <scsi/scsi_host.h>
  #include <scsi/scsi_cmnd.h>
  #include <linux/libata.h>
  
  #define DRV_NAME	"pata_pdc2027x"
  #define DRV_VERSION	"1.0"
  #undef PDC_DEBUG
  
  #ifdef PDC_DEBUG
  #define PDPRINTK(fmt, args...) printk(KERN_ERR "%s: " fmt, __func__, ## args)
  #else
  #define PDPRINTK(fmt, args...)
  #endif
  
  enum {
  	PDC_MMIO_BAR		= 5,
  
  	PDC_UDMA_100		= 0,
  	PDC_UDMA_133		= 1,
  
  	PDC_100_MHZ		= 100000000,
  	PDC_133_MHZ		= 133333333,
  
  	PDC_SYS_CTL		= 0x1100,
  	PDC_ATA_CTL		= 0x1104,
  	PDC_GLOBAL_CTL		= 0x1108,
  	PDC_CTCR0		= 0x110C,
  	PDC_CTCR1		= 0x1110,
  	PDC_BYTE_COUNT		= 0x1120,
  	PDC_PLL_CTL		= 0x1202,
  };
  
  static int pdc2027x_init_one(struct pci_dev *pdev, const struct pci_device_id *ent);
  #ifdef CONFIG_PM_SLEEP
  static int pdc2027x_reinit_one(struct pci_dev *pdev);
  #endif
  static int pdc2027x_prereset(struct ata_link *link, unsigned long deadline);
  static void pdc2027x_set_piomode(struct ata_port *ap, struct ata_device *adev);
  static void pdc2027x_set_dmamode(struct ata_port *ap, struct ata_device *adev);
  static int pdc2027x_check_atapi_dma(struct ata_queued_cmd *qc);
  static unsigned long pdc2027x_mode_filter(struct ata_device *adev, unsigned long mask);
  static int pdc2027x_cable_detect(struct ata_port *ap);
  static int pdc2027x_set_mode(struct ata_link *link, struct ata_device **r_failed);
  
  /*
   * ATA Timing Tables based on 133MHz controller clock.
   * These tables are only used when the controller is in 133MHz clock.
   * If the controller is in 100MHz clock, the ASIC hardware will
   * set the timing registers automatically when "set feature" command
   * is issued to the device. However, if the controller clock is 133MHz,
   * the following tables must be used.
   */
  static struct pdc2027x_pio_timing {
  	u8 value0, value1, value2;
  } pdc2027x_pio_timing_tbl [] = {
  	{ 0xfb, 0x2b, 0xac }, /* PIO mode 0 */
  	{ 0x46, 0x29, 0xa4 }, /* PIO mode 1 */
  	{ 0x23, 0x26, 0x64 }, /* PIO mode 2 */
  	{ 0x27, 0x0d, 0x35 }, /* PIO mode 3, IORDY on, Prefetch off */
  	{ 0x23, 0x09, 0x25 }, /* PIO mode 4, IORDY on, Prefetch off */
  };
  
  static struct pdc2027x_mdma_timing {
  	u8 value0, value1;
  } pdc2027x_mdma_timing_tbl [] = {
  	{ 0xdf, 0x5f }, /* MDMA mode 0 */
  	{ 0x6b, 0x27 }, /* MDMA mode 1 */
  	{ 0x69, 0x25 }, /* MDMA mode 2 */
  };
  
  static struct pdc2027x_udma_timing {
  	u8 value0, value1, value2;
  } pdc2027x_udma_timing_tbl [] = {
  	{ 0x4a, 0x0f, 0xd5 }, /* UDMA mode 0 */
  	{ 0x3a, 0x0a, 0xd0 }, /* UDMA mode 1 */
  	{ 0x2a, 0x07, 0xcd }, /* UDMA mode 2 */
  	{ 0x1a, 0x05, 0xcd }, /* UDMA mode 3 */
  	{ 0x1a, 0x03, 0xcd }, /* UDMA mode 4 */
  	{ 0x1a, 0x02, 0xcb }, /* UDMA mode 5 */
  	{ 0x1a, 0x01, 0xcb }, /* UDMA mode 6 */
  };
  
  static const struct pci_device_id pdc2027x_pci_tbl[] = {
  	{ PCI_VDEVICE(PROMISE, PCI_DEVICE_ID_PROMISE_20268), PDC_UDMA_100 },
  	{ PCI_VDEVICE(PROMISE, PCI_DEVICE_ID_PROMISE_20269), PDC_UDMA_133 },
  	{ PCI_VDEVICE(PROMISE, PCI_DEVICE_ID_PROMISE_20270), PDC_UDMA_100 },
  	{ PCI_VDEVICE(PROMISE, PCI_DEVICE_ID_PROMISE_20271), PDC_UDMA_133 },
  	{ PCI_VDEVICE(PROMISE, PCI_DEVICE_ID_PROMISE_20275), PDC_UDMA_133 },
  	{ PCI_VDEVICE(PROMISE, PCI_DEVICE_ID_PROMISE_20276), PDC_UDMA_133 },
  	{ PCI_VDEVICE(PROMISE, PCI_DEVICE_ID_PROMISE_20277), PDC_UDMA_133 },
  
  	{ }	/* terminate list */
  };
  
  static struct pci_driver pdc2027x_pci_driver = {
  	.name			= DRV_NAME,
  	.id_table		= pdc2027x_pci_tbl,
  	.probe			= pdc2027x_init_one,
  	.remove			= ata_pci_remove_one,
  #ifdef CONFIG_PM_SLEEP
  	.suspend		= ata_pci_device_suspend,
  	.resume			= pdc2027x_reinit_one,
  #endif
  };
  
  static struct scsi_host_template pdc2027x_sht = {
  	ATA_BMDMA_SHT(DRV_NAME),
  };
  
  static struct ata_port_operations pdc2027x_pata100_ops = {
  	.inherits		= &ata_bmdma_port_ops,
  	.check_atapi_dma	= pdc2027x_check_atapi_dma,
  	.cable_detect		= pdc2027x_cable_detect,
  	.prereset		= pdc2027x_prereset,
  };
  
  static struct ata_port_operations pdc2027x_pata133_ops = {
  	.inherits		= &pdc2027x_pata100_ops,
  	.mode_filter		= pdc2027x_mode_filter,
  	.set_piomode		= pdc2027x_set_piomode,
  	.set_dmamode		= pdc2027x_set_dmamode,
  	.set_mode		= pdc2027x_set_mode,
  };
  
  static struct ata_port_info pdc2027x_port_info[] = {
  	/* PDC_UDMA_100 */
  	{
  		.flags		= ATA_FLAG_SLAVE_POSS,
  		.pio_mask	= ATA_PIO4,
  		.mwdma_mask	= ATA_MWDMA2,
  		.udma_mask	= ATA_UDMA5,
  		.port_ops	= &pdc2027x_pata100_ops,
  	},
  	/* PDC_UDMA_133 */
  	{
  		.flags		= ATA_FLAG_SLAVE_POSS,
  		.pio_mask	= ATA_PIO4,
  		.mwdma_mask	= ATA_MWDMA2,
  		.udma_mask	= ATA_UDMA6,
  		.port_ops	= &pdc2027x_pata133_ops,
  	},
  };
  
  MODULE_AUTHOR("Andre Hedrick, Frank Tiernan, Albert Lee");
  MODULE_DESCRIPTION("libata driver module for Promise PDC20268 to PDC20277");
  MODULE_LICENSE("GPL");
  MODULE_VERSION(DRV_VERSION);
  MODULE_DEVICE_TABLE(pci, pdc2027x_pci_tbl);
  
  /**
   *	port_mmio - Get the MMIO address of PDC2027x extended registers
   *	@ap: Port
   *	@offset: offset from mmio base
   */
  static inline void __iomem *port_mmio(struct ata_port *ap, unsigned int offset)
  {
  	return ap->host->iomap[PDC_MMIO_BAR] + ap->port_no * 0x100 + offset;
  }
  
  /**
   *	dev_mmio - Get the MMIO address of PDC2027x extended registers
   *	@ap: Port
   *	@adev: device
   *	@offset: offset from mmio base
   */
  static inline void __iomem *dev_mmio(struct ata_port *ap, struct ata_device *adev, unsigned int offset)
  {
  	u8 adj = (adev->devno) ? 0x08 : 0x00;
  	return port_mmio(ap, offset) + adj;
  }
  
  /**
   *	pdc2027x_pata_cable_detect - Probe host controller cable detect info
   *	@ap: Port for which cable detect info is desired
   *
   *	Read 80c cable indicator from Promise extended register.
   *      This register is latched when the system is reset.
   *
   *	LOCKING:
   *	None (inherited from caller).
   */
  static int pdc2027x_cable_detect(struct ata_port *ap)
  {
  	u32 cgcr;
  
  	/* check cable detect results */
  	cgcr = ioread32(port_mmio(ap, PDC_GLOBAL_CTL));
  	if (cgcr & (1 << 26))
  		goto cbl40;
  
  	PDPRINTK("No cable or 80-conductor cable on port %d
  ", ap->port_no);
  
  	return ATA_CBL_PATA80;
  cbl40:
  	printk(KERN_INFO DRV_NAME ": 40-conductor cable detected on port %d
  ", ap->port_no);
  	return ATA_CBL_PATA40;
  }
  
  /**
   * pdc2027x_port_enabled - Check PDC ATA control register to see whether the port is enabled.
   * @ap: Port to check
   */
  static inline int pdc2027x_port_enabled(struct ata_port *ap)
  {
  	return ioread8(port_mmio(ap, PDC_ATA_CTL)) & 0x02;
  }
  
  /**
   *	pdc2027x_prereset - prereset for PATA host controller
   *	@link: Target link
   *	@deadline: deadline jiffies for the operation
   *
   *	Probeinit including cable detection.
   *
   *	LOCKING:
   *	None (inherited from caller).
   */
  
  static int pdc2027x_prereset(struct ata_link *link, unsigned long deadline)
  {
  	/* Check whether port enabled */
  	if (!pdc2027x_port_enabled(link->ap))
  		return -ENOENT;
  	return ata_sff_prereset(link, deadline);
  }
  
  /**
   *	pdc2720x_mode_filter	-	mode selection filter
   *	@adev: ATA device
   *	@mask: list of modes proposed
   *
   *	Block UDMA on devices that cause trouble with this controller.
   */
  
  static unsigned long pdc2027x_mode_filter(struct ata_device *adev, unsigned long mask)
  {
  	unsigned char model_num[ATA_ID_PROD_LEN + 1];
  	struct ata_device *pair = ata_dev_pair(adev);
  
  	if (adev->class != ATA_DEV_ATA || adev->devno == 0 || pair == NULL)
  		return mask;
  
  	/* Check for slave of a Maxtor at UDMA6 */
  	ata_id_c_string(pair->id, model_num, ATA_ID_PROD,
  			  ATA_ID_PROD_LEN + 1);
  	/* If the master is a maxtor in UDMA6 then the slave should not use UDMA 6 */
  	if (strstr(model_num, "Maxtor") == NULL && pair->dma_mode == XFER_UDMA_6)
  		mask &= ~ (1 << (6 + ATA_SHIFT_UDMA));
  
  	return mask;
  }
  
  /**
   *	pdc2027x_set_piomode - Initialize host controller PATA PIO timings
   *	@ap: Port to configure
   *	@adev: um
   *
   *	Set PIO mode for device.
   *
   *	LOCKING:
   *	None (inherited from caller).
   */
  
  static void pdc2027x_set_piomode(struct ata_port *ap, struct ata_device *adev)
  {
  	unsigned int pio = adev->pio_mode - XFER_PIO_0;
  	u32 ctcr0, ctcr1;
  
  	PDPRINTK("adev->pio_mode[%X]
  ", adev->pio_mode);
  
  	/* Sanity check */
  	if (pio > 4) {
  		printk(KERN_ERR DRV_NAME ": Unknown pio mode [%d] ignored
  ", pio);
  		return;
  
  	}
  
  	/* Set the PIO timing registers using value table for 133MHz */
  	PDPRINTK("Set pio regs... 
  ");
  
  	ctcr0 = ioread32(dev_mmio(ap, adev, PDC_CTCR0));
  	ctcr0 &= 0xffff0000;
  	ctcr0 |= pdc2027x_pio_timing_tbl[pio].value0 |
  		(pdc2027x_pio_timing_tbl[pio].value1 << 8);
  	iowrite32(ctcr0, dev_mmio(ap, adev, PDC_CTCR0));
  
  	ctcr1 = ioread32(dev_mmio(ap, adev, PDC_CTCR1));
  	ctcr1 &= 0x00ffffff;
  	ctcr1 |= (pdc2027x_pio_timing_tbl[pio].value2 << 24);
  	iowrite32(ctcr1, dev_mmio(ap, adev, PDC_CTCR1));
  
  	PDPRINTK("Set pio regs done
  ");
  
  	PDPRINTK("Set to pio mode[%u] 
  ", pio);
  }
  
  /**
   *	pdc2027x_set_dmamode - Initialize host controller PATA UDMA timings
   *	@ap: Port to configure
   *	@adev: um
   *
   *	Set UDMA mode for device.
   *
   *	LOCKING:
   *	None (inherited from caller).
   */
  static void pdc2027x_set_dmamode(struct ata_port *ap, struct ata_device *adev)
  {
  	unsigned int dma_mode = adev->dma_mode;
  	u32 ctcr0, ctcr1;
  
  	if ((dma_mode >= XFER_UDMA_0) &&
  	   (dma_mode <= XFER_UDMA_6)) {
  		/* Set the UDMA timing registers with value table for 133MHz */
  		unsigned int udma_mode = dma_mode & 0x07;
  
  		if (dma_mode == XFER_UDMA_2) {
  			/*
  			 * Turn off tHOLD.
  			 * If tHOLD is '1', the hardware will add half clock for data hold time.
  			 * This code segment seems to be no effect. tHOLD will be overwritten below.
  			 */
  			ctcr1 = ioread32(dev_mmio(ap, adev, PDC_CTCR1));
  			iowrite32(ctcr1 & ~(1 << 7), dev_mmio(ap, adev, PDC_CTCR1));
  		}
  
  		PDPRINTK("Set udma regs... 
  ");
  
  		ctcr1 = ioread32(dev_mmio(ap, adev, PDC_CTCR1));
  		ctcr1 &= 0xff000000;
  		ctcr1 |= pdc2027x_udma_timing_tbl[udma_mode].value0 |
  			(pdc2027x_udma_timing_tbl[udma_mode].value1 << 8) |
  			(pdc2027x_udma_timing_tbl[udma_mode].value2 << 16);
  		iowrite32(ctcr1, dev_mmio(ap, adev, PDC_CTCR1));
  
  		PDPRINTK("Set udma regs done
  ");
  
  		PDPRINTK("Set to udma mode[%u] 
  ", udma_mode);
  
  	} else  if ((dma_mode >= XFER_MW_DMA_0) &&
  		   (dma_mode <= XFER_MW_DMA_2)) {
  		/* Set the MDMA timing registers with value table for 133MHz */
  		unsigned int mdma_mode = dma_mode & 0x07;
  
  		PDPRINTK("Set mdma regs... 
  ");
  		ctcr0 = ioread32(dev_mmio(ap, adev, PDC_CTCR0));
  
  		ctcr0 &= 0x0000ffff;
  		ctcr0 |= (pdc2027x_mdma_timing_tbl[mdma_mode].value0 << 16) |
  			(pdc2027x_mdma_timing_tbl[mdma_mode].value1 << 24);
  
  		iowrite32(ctcr0, dev_mmio(ap, adev, PDC_CTCR0));
  		PDPRINTK("Set mdma regs done
  ");
  
  		PDPRINTK("Set to mdma mode[%u] 
  ", mdma_mode);
  	} else {
  		printk(KERN_ERR DRV_NAME ": Unknown dma mode [%u] ignored
  ", dma_mode);
  	}
  }
  
  /**
   *	pdc2027x_set_mode - Set the timing registers back to correct values.
   *	@link: link to configure
   *	@r_failed: Returned device for failure
   *
   *	The pdc2027x hardware will look at "SET FEATURES" and change the timing registers
   *	automatically. The values set by the hardware might be incorrect, under 133Mhz PLL.
   *	This function overwrites the possibly incorrect values set by the hardware to be correct.
   */
  static int pdc2027x_set_mode(struct ata_link *link, struct ata_device **r_failed)
  {
  	struct ata_port *ap = link->ap;
  	struct ata_device *dev;
  	int rc;
  
  	rc = ata_do_set_mode(link, r_failed);
  	if (rc < 0)
  		return rc;
  
  	ata_for_each_dev(dev, link, ENABLED) {
  		pdc2027x_set_piomode(ap, dev);
  
  		/*
  		 * Enable prefetch if the device support PIO only.
  		 */
  		if (dev->xfer_shift == ATA_SHIFT_PIO) {
  			u32 ctcr1 = ioread32(dev_mmio(ap, dev, PDC_CTCR1));
  			ctcr1 |= (1 << 25);
  			iowrite32(ctcr1, dev_mmio(ap, dev, PDC_CTCR1));
  
  			PDPRINTK("Turn on prefetch
  ");
  		} else {
  			pdc2027x_set_dmamode(ap, dev);
  		}
  	}
  	return 0;
  }
  
  /**
   *	pdc2027x_check_atapi_dma - Check whether ATAPI DMA can be supported for this command
   *	@qc: Metadata associated with taskfile to check
   *
   *	LOCKING:
   *	None (inherited from caller).
   *
   *	RETURNS: 0 when ATAPI DMA can be used
   *		 1 otherwise
   */
  static int pdc2027x_check_atapi_dma(struct ata_queued_cmd *qc)
  {
  	struct scsi_cmnd *cmd = qc->scsicmd;
  	u8 *scsicmd = cmd->cmnd;
  	int rc = 1; /* atapi dma off by default */
  
  	/*
  	 * This workaround is from Promise's GPL driver.
  	 * If ATAPI DMA is used for commands not in the
  	 * following white list, say MODE_SENSE and REQUEST_SENSE,
  	 * pdc2027x might hit the irq lost problem.
  	 */
  	switch (scsicmd[0]) {
  	case READ_10:
  	case WRITE_10:
  	case READ_12:
  	case WRITE_12:
  	case READ_6:
  	case WRITE_6:
  	case 0xad: /* READ_DVD_STRUCTURE */
  	case 0xbe: /* READ_CD */
  		/* ATAPI DMA is ok */
  		rc = 0;
  		break;
  	default:
  		;
  	}
  
  	return rc;
  }
  
  /**
   * pdc_read_counter - Read the ctr counter
   * @host: target ATA host
   */
  
  static long pdc_read_counter(struct ata_host *host)
  {
  	void __iomem *mmio_base = host->iomap[PDC_MMIO_BAR];
  	long counter;
  	int retry = 1;
  	u32 bccrl, bccrh, bccrlv, bccrhv;
  
  retry:
  	bccrl = ioread32(mmio_base + PDC_BYTE_COUNT) & 0x7fff;
  	bccrh = ioread32(mmio_base + PDC_BYTE_COUNT + 0x100) & 0x7fff;
  
  	/* Read the counter values again for verification */
  	bccrlv = ioread32(mmio_base + PDC_BYTE_COUNT) & 0x7fff;
  	bccrhv = ioread32(mmio_base + PDC_BYTE_COUNT + 0x100) & 0x7fff;
  
  	counter = (bccrh << 15) | bccrl;
  
  	PDPRINTK("bccrh [%X] bccrl [%X]
  ", bccrh,  bccrl);
  	PDPRINTK("bccrhv[%X] bccrlv[%X]
  ", bccrhv, bccrlv);
  
  	/*
  	 * The 30-bit decreasing counter are read by 2 pieces.
  	 * Incorrect value may be read when both bccrh and bccrl are changing.
  	 * Ex. When 7900 decrease to 78FF, wrong value 7800 might be read.
  	 */
  	if (retry && !(bccrh == bccrhv && bccrl >= bccrlv)) {
  		retry--;
  		PDPRINTK("rereading counter
  ");
  		goto retry;
  	}
  
  	return counter;
  }
  
  /**
   * adjust_pll - Adjust the PLL input clock in Hz.
   *
   * @pdc_controller: controller specific information
   * @host: target ATA host
   * @pll_clock: The input of PLL in HZ
   */
  static void pdc_adjust_pll(struct ata_host *host, long pll_clock, unsigned int board_idx)
  {
  	void __iomem *mmio_base = host->iomap[PDC_MMIO_BAR];
  	u16 pll_ctl;
  	long pll_clock_khz = pll_clock / 1000;
  	long pout_required = board_idx? PDC_133_MHZ:PDC_100_MHZ;
  	long ratio = pout_required / pll_clock_khz;
  	int F, R;
  
  	/* Sanity check */
  	if (unlikely(pll_clock_khz < 5000L || pll_clock_khz > 70000L)) {
  		printk(KERN_ERR DRV_NAME ": Invalid PLL input clock %ldkHz, give up!
  ", pll_clock_khz);
  		return;
  	}
  
  #ifdef PDC_DEBUG
  	PDPRINTK("pout_required is %ld
  ", pout_required);
  
  	/* Show the current clock value of PLL control register
  	 * (maybe already configured by the firmware)
  	 */
  	pll_ctl = ioread16(mmio_base + PDC_PLL_CTL);
  
  	PDPRINTK("pll_ctl[%X]
  ", pll_ctl);
  #endif
  
  	/*
  	 * Calculate the ratio of F, R and OD
  	 * POUT = (F + 2) / (( R + 2) * NO)
  	 */
  	if (ratio < 8600L) { /* 8.6x */
  		/* Using NO = 0x01, R = 0x0D */
  		R = 0x0d;
  	} else if (ratio < 12900L) { /* 12.9x */
  		/* Using NO = 0x01, R = 0x08 */
  		R = 0x08;
  	} else if (ratio < 16100L) { /* 16.1x */
  		/* Using NO = 0x01, R = 0x06 */
  		R = 0x06;
  	} else if (ratio < 64000L) { /* 64x */
  		R = 0x00;
  	} else {
  		/* Invalid ratio */
  		printk(KERN_ERR DRV_NAME ": Invalid ratio %ld, give up!
  ", ratio);
  		return;
  	}
  
  	F = (ratio * (R+2)) / 1000 - 2;
  
  	if (unlikely(F < 0 || F > 127)) {
  		/* Invalid F */
  		printk(KERN_ERR DRV_NAME ": F[%d] invalid!
  ", F);
  		return;
  	}
  
  	PDPRINTK("F[%d] R[%d] ratio*1000[%ld]
  ", F, R, ratio);
  
  	pll_ctl = (R << 8) | F;
  
  	PDPRINTK("Writing pll_ctl[%X]
  ", pll_ctl);
  
  	iowrite16(pll_ctl, mmio_base + PDC_PLL_CTL);
  	ioread16(mmio_base + PDC_PLL_CTL); /* flush */
  
  	/* Wait the PLL circuit to be stable */
  	mdelay(30);
  
  #ifdef PDC_DEBUG
  	/*
  	 *  Show the current clock value of PLL control register
  	 * (maybe configured by the firmware)
  	 */
  	pll_ctl = ioread16(mmio_base + PDC_PLL_CTL);
  
  	PDPRINTK("pll_ctl[%X]
  ", pll_ctl);
  #endif
  
  	return;
  }
  
  /**
   * detect_pll_input_clock - Detect the PLL input clock in Hz.
   * @host: target ATA host
   * Ex. 16949000 on 33MHz PCI bus for pdc20275.
   *     Half of the PCI clock.
   */
  static long pdc_detect_pll_input_clock(struct ata_host *host)
  {
  	void __iomem *mmio_base = host->iomap[PDC_MMIO_BAR];
  	u32 scr;
  	long start_count, end_count;
  	struct timeval start_time, end_time;
  	long pll_clock, usec_elapsed;
  
  	/* Start the test mode */
  	scr = ioread32(mmio_base + PDC_SYS_CTL);
  	PDPRINTK("scr[%X]
  ", scr);
  	iowrite32(scr | (0x01 << 14), mmio_base + PDC_SYS_CTL);
  	ioread32(mmio_base + PDC_SYS_CTL); /* flush */
  
  	/* Read current counter value */
  	start_count = pdc_read_counter(host);
  	do_gettimeofday(&start_time);
  
  	/* Let the counter run for 100 ms. */
  	mdelay(100);
  
  	/* Read the counter values again */
  	end_count = pdc_read_counter(host);
  	do_gettimeofday(&end_time);
  
  	/* Stop the test mode */
  	scr = ioread32(mmio_base + PDC_SYS_CTL);
  	PDPRINTK("scr[%X]
  ", scr);
  	iowrite32(scr & ~(0x01 << 14), mmio_base + PDC_SYS_CTL);
  	ioread32(mmio_base + PDC_SYS_CTL); /* flush */
  
  	/* calculate the input clock in Hz */
  	usec_elapsed = (end_time.tv_sec - start_time.tv_sec) * 1000000 +
  		(end_time.tv_usec - start_time.tv_usec);
  
  	pll_clock = ((start_count - end_count) & 0x3fffffff) / 100 *
  		(100000000 / usec_elapsed);
  
  	PDPRINTK("start[%ld] end[%ld] 
  ", start_count, end_count);
  	PDPRINTK("PLL input clock[%ld]Hz
  ", pll_clock);
  
  	return pll_clock;
  }
  
  /**
   * pdc_hardware_init - Initialize the hardware.
   * @host: target ATA host
   * @board_idx: board identifier
   */
  static int pdc_hardware_init(struct ata_host *host, unsigned int board_idx)
  {
  	long pll_clock;
  
  	/*
  	 * Detect PLL input clock rate.
  	 * On some system, where PCI bus is running at non-standard clock rate.
  	 * Ex. 25MHz or 40MHz, we have to adjust the cycle_time.
  	 * The pdc20275 controller employs PLL circuit to help correct timing registers setting.
  	 */
  	pll_clock = pdc_detect_pll_input_clock(host);
  
  	dev_info(host->dev, "PLL input clock %ld kHz
  ", pll_clock/1000);
  
  	/* Adjust PLL control register */
  	pdc_adjust_pll(host, pll_clock, board_idx);
  
  	return 0;
  }
  
  /**
   * pdc_ata_setup_port - setup the mmio address
   * @port: ata ioports to setup
   * @base: base address
   */
  static void pdc_ata_setup_port(struct ata_ioports *port, void __iomem *base)
  {
  	port->cmd_addr		=
  	port->data_addr		= base;
  	port->feature_addr	=
  	port->error_addr	= base + 0x05;
  	port->nsect_addr	= base + 0x0a;
  	port->lbal_addr		= base + 0x0f;
  	port->lbam_addr		= base + 0x10;
  	port->lbah_addr		= base + 0x15;
  	port->device_addr	= base + 0x1a;
  	port->command_addr	=
  	port->status_addr	= base + 0x1f;
  	port->altstatus_addr	=
  	port->ctl_addr		= base + 0x81a;
  }
  
  /**
   * pdc2027x_init_one - PCI probe function
   * Called when an instance of PCI adapter is inserted.
   * This function checks whether the hardware is supported,
   * initialize hardware and register an instance of ata_host to
   * libata.  (implements struct pci_driver.probe() )
   *
   * @pdev: instance of pci_dev found
   * @ent:  matching entry in the id_tbl[]
   */
  static int pdc2027x_init_one(struct pci_dev *pdev,
  			     const struct pci_device_id *ent)
  {
  	static const unsigned long cmd_offset[] = { 0x17c0, 0x15c0 };
  	static const unsigned long bmdma_offset[] = { 0x1000, 0x1008 };
  	unsigned int board_idx = (unsigned int) ent->driver_data;
  	const struct ata_port_info *ppi[] =
  		{ &pdc2027x_port_info[board_idx], NULL };
  	struct ata_host *host;
  	void __iomem *mmio_base;
  	int i, rc;
  
  	ata_print_version_once(&pdev->dev, DRV_VERSION);
  
  	/* alloc host */
  	host = ata_host_alloc_pinfo(&pdev->dev, ppi, 2);
  	if (!host)
  		return -ENOMEM;
  
  	/* acquire resources and fill host */
  	rc = pcim_enable_device(pdev);
  	if (rc)
  		return rc;
  
  	rc = pcim_iomap_regions(pdev, 1 << PDC_MMIO_BAR, DRV_NAME);
  	if (rc)
  		return rc;
  	host->iomap = pcim_iomap_table(pdev);
  
  	rc = pci_set_dma_mask(pdev, ATA_DMA_MASK);
  	if (rc)
  		return rc;
  
  	rc = pci_set_consistent_dma_mask(pdev, ATA_DMA_MASK);
  	if (rc)
  		return rc;
  
  	mmio_base = host->iomap[PDC_MMIO_BAR];
  
  	for (i = 0; i < 2; i++) {
  		struct ata_port *ap = host->ports[i];
  
  		pdc_ata_setup_port(&ap->ioaddr, mmio_base + cmd_offset[i]);
  		ap->ioaddr.bmdma_addr = mmio_base + bmdma_offset[i];
  
  		ata_port_pbar_desc(ap, PDC_MMIO_BAR, -1, "mmio");
  		ata_port_pbar_desc(ap, PDC_MMIO_BAR, cmd_offset[i], "cmd");
  	}
  
  	//pci_enable_intx(pdev);
  
  	/* initialize adapter */
  	if (pdc_hardware_init(host, board_idx) != 0)
  		return -EIO;
  
  	pci_set_master(pdev);
  	return ata_host_activate(host, pdev->irq, ata_bmdma_interrupt,
  				 IRQF_SHARED, &pdc2027x_sht);
  }
  
  #ifdef CONFIG_PM_SLEEP
  static int pdc2027x_reinit_one(struct pci_dev *pdev)
  {
  	struct ata_host *host = pci_get_drvdata(pdev);
  	unsigned int board_idx;
  	int rc;
  
  	rc = ata_pci_device_do_resume(pdev);
  	if (rc)
  		return rc;
  
  	if (pdev->device == PCI_DEVICE_ID_PROMISE_20268 ||
  	    pdev->device == PCI_DEVICE_ID_PROMISE_20270)
  		board_idx = PDC_UDMA_100;
  	else
  		board_idx = PDC_UDMA_133;
  
  	if (pdc_hardware_init(host, board_idx))
  		return -EIO;
  
  	ata_host_resume(host);
  	return 0;
  }
  #endif
  
  module_pci_driver(pdc2027x_pci_driver);