/*
   *  sata_vsc.c - Vitesse VSC7174 4 port DPA SATA
   *
   *  Maintained by:  Jeremy Higdon @ SGI
   * 		    Please ALWAYS copy linux-ide@vger.kernel.org
   *		    on emails.
   *
   *  Copyright 2004 SGI
   *
   *  Bits from Jeff Garzik, Copyright RedHat, Inc.
   *

   *
   *  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, or (at your option)
   *  any later version.
   *
   *  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; see the file COPYING.  If not, write to
   *  the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.
   *
   *
   *  libata documentation is available via 'make {ps|pdf}docs',
   *  as Documentation/DocBook/libata.*
   *
   *  Vitesse hardware documentation presumably available under NDA.
   *  Intel 31244 (same hardware interface) documentation presumably
   *  available from http://developer.intel.com/
   *

   */
  
  #include <linux/kernel.h>
  #include <linux/module.h>
  #include <linux/pci.h>
  #include <linux/init.h>
  #include <linux/blkdev.h>
  #include <linux/delay.h>
  #include <linux/interrupt.h>

  #include <linux/dma-mapping.h>

  #include <linux/device.h>

  #include <scsi/scsi_host.h>
  #include <linux/libata.h>
  
  #define DRV_NAME	"sata_vsc"

  #define DRV_VERSION	"2.3"

  enum {

  	VSC_MMIO_BAR			= 0,

  	/* Interrupt register offsets (from chip base address) */
  	VSC_SATA_INT_STAT_OFFSET	= 0x00,
  	VSC_SATA_INT_MASK_OFFSET	= 0x04,

  	/* Taskfile registers offsets */
  	VSC_SATA_TF_CMD_OFFSET		= 0x00,
  	VSC_SATA_TF_DATA_OFFSET		= 0x00,
  	VSC_SATA_TF_ERROR_OFFSET	= 0x04,
  	VSC_SATA_TF_FEATURE_OFFSET	= 0x06,
  	VSC_SATA_TF_NSECT_OFFSET	= 0x08,
  	VSC_SATA_TF_LBAL_OFFSET		= 0x0c,
  	VSC_SATA_TF_LBAM_OFFSET		= 0x10,
  	VSC_SATA_TF_LBAH_OFFSET		= 0x14,
  	VSC_SATA_TF_DEVICE_OFFSET	= 0x18,
  	VSC_SATA_TF_STATUS_OFFSET	= 0x1c,
  	VSC_SATA_TF_COMMAND_OFFSET	= 0x1d,
  	VSC_SATA_TF_ALTSTATUS_OFFSET	= 0x28,
  	VSC_SATA_TF_CTL_OFFSET		= 0x29,

  	/* DMA base */
  	VSC_SATA_UP_DESCRIPTOR_OFFSET	= 0x64,
  	VSC_SATA_UP_DATA_BUFFER_OFFSET	= 0x6C,
  	VSC_SATA_DMA_CMD_OFFSET		= 0x70,

  	/* SCRs base */
  	VSC_SATA_SCR_STATUS_OFFSET	= 0x100,
  	VSC_SATA_SCR_ERROR_OFFSET	= 0x104,
  	VSC_SATA_SCR_CONTROL_OFFSET	= 0x108,

  	/* Port stride */
  	VSC_SATA_PORT_OFFSET		= 0x200,
  
  	/* Error interrupt status bit offsets */
  	VSC_SATA_INT_ERROR_CRC		= 0x40,
  	VSC_SATA_INT_ERROR_T		= 0x20,
  	VSC_SATA_INT_ERROR_P		= 0x10,
  	VSC_SATA_INT_ERROR_R		= 0x8,
  	VSC_SATA_INT_ERROR_E		= 0x4,
  	VSC_SATA_INT_ERROR_M		= 0x2,
  	VSC_SATA_INT_PHY_CHANGE		= 0x1,
  	VSC_SATA_INT_ERROR = (VSC_SATA_INT_ERROR_CRC  | VSC_SATA_INT_ERROR_T | \
  			      VSC_SATA_INT_ERROR_P    | VSC_SATA_INT_ERROR_R | \
  			      VSC_SATA_INT_ERROR_E    | VSC_SATA_INT_ERROR_M | \
  			      VSC_SATA_INT_PHY_CHANGE),

  };

  static int vsc_sata_scr_read(struct ata_link *link,
  			     unsigned int sc_reg, u32 *val)

  {
  	if (sc_reg > SCR_CONTROL)

  		return -EINVAL;

  	*val = readl(link->ap->ioaddr.scr_addr + (sc_reg * 4));

  	return 0;

  }

  static int vsc_sata_scr_write(struct ata_link *link,
  			      unsigned int sc_reg, u32 val)

  {
  	if (sc_reg > SCR_CONTROL)

  		return -EINVAL;

  	writel(val, link->ap->ioaddr.scr_addr + (sc_reg * 4));

  	return 0;

  }

  static void vsc_freeze(struct ata_port *ap)
  {
  	void __iomem *mask_addr;
  
  	mask_addr = ap->host->iomap[VSC_MMIO_BAR] +
  		VSC_SATA_INT_MASK_OFFSET + ap->port_no;
  
  	writeb(0, mask_addr);
  }
  
  
  static void vsc_thaw(struct ata_port *ap)
  {
  	void __iomem *mask_addr;
  
  	mask_addr = ap->host->iomap[VSC_MMIO_BAR] +
  		VSC_SATA_INT_MASK_OFFSET + ap->port_no;
  
  	writeb(0xff, mask_addr);
  }

  static void vsc_intr_mask_update(struct ata_port *ap, u8 ctl)
  {

  	void __iomem *mask_addr;

  	u8 mask;

  	mask_addr = ap->host->iomap[VSC_MMIO_BAR] +

  		VSC_SATA_INT_MASK_OFFSET + ap->port_no;
  	mask = readb(mask_addr);
  	if (ctl & ATA_NIEN)
  		mask |= 0x80;
  	else
  		mask &= 0x7F;
  	writeb(mask, mask_addr);
  }

  static void vsc_sata_tf_load(struct ata_port *ap, const struct ata_taskfile *tf)

  {
  	struct ata_ioports *ioaddr = &ap->ioaddr;
  	unsigned int is_addr = tf->flags & ATA_TFLAG_ISADDR;
  
  	/*
  	 * The only thing the ctl register is used for is SRST.
  	 * That is not enabled or disabled via tf_load.

  	 * However, if ATA_NIEN is changed, then we need to change
  	 * the interrupt register.

  	 */
  	if ((tf->ctl & ATA_NIEN) != (ap->last_ctl & ATA_NIEN)) {
  		ap->last_ctl = tf->ctl;
  		vsc_intr_mask_update(ap, tf->ctl & ATA_NIEN);
  	}
  	if (is_addr && (tf->flags & ATA_TFLAG_LBA48)) {

  		writew(tf->feature | (((u16)tf->hob_feature) << 8),

  		       ioaddr->feature_addr);

  		writew(tf->nsect | (((u16)tf->hob_nsect) << 8),

  		       ioaddr->nsect_addr);

  		writew(tf->lbal | (((u16)tf->hob_lbal) << 8),

  		       ioaddr->lbal_addr);

  		writew(tf->lbam | (((u16)tf->hob_lbam) << 8),

  		       ioaddr->lbam_addr);

  		writew(tf->lbah | (((u16)tf->hob_lbah) << 8),

  		       ioaddr->lbah_addr);

  	} else if (is_addr) {

  		writew(tf->feature, ioaddr->feature_addr);
  		writew(tf->nsect, ioaddr->nsect_addr);
  		writew(tf->lbal, ioaddr->lbal_addr);
  		writew(tf->lbam, ioaddr->lbam_addr);
  		writew(tf->lbah, ioaddr->lbah_addr);

  	}
  
  	if (tf->flags & ATA_TFLAG_DEVICE)

  		writeb(tf->device, ioaddr->device_addr);

  
  	ata_wait_idle(ap);
  }
  
  
  static void vsc_sata_tf_read(struct ata_port *ap, struct ata_taskfile *tf)
  {
  	struct ata_ioports *ioaddr = &ap->ioaddr;

  	u16 nsect, lbal, lbam, lbah, feature;

  	tf->command = ata_sff_check_status(ap);

  	tf->device = readw(ioaddr->device_addr);
  	feature = readw(ioaddr->error_addr);
  	nsect = readw(ioaddr->nsect_addr);
  	lbal = readw(ioaddr->lbal_addr);
  	lbam = readw(ioaddr->lbam_addr);
  	lbah = readw(ioaddr->lbah_addr);

  
  	tf->feature = feature;
  	tf->nsect = nsect;
  	tf->lbal = lbal;
  	tf->lbam = lbam;
  	tf->lbah = lbah;

  
  	if (tf->flags & ATA_TFLAG_LBA48) {

  		tf->hob_feature = feature >> 8;

  		tf->hob_nsect = nsect >> 8;
  		tf->hob_lbal = lbal >> 8;
  		tf->hob_lbam = lbam >> 8;
  		tf->hob_lbah = lbah >> 8;

  	}

  }

  static inline void vsc_error_intr(u8 port_status, struct ata_port *ap)
  {
  	if (port_status & (VSC_SATA_INT_PHY_CHANGE | VSC_SATA_INT_ERROR_M))
  		ata_port_freeze(ap);
  	else
  		ata_port_abort(ap);
  }
  
  static void vsc_port_intr(u8 port_status, struct ata_port *ap)
  {
  	struct ata_queued_cmd *qc;
  	int handled = 0;
  
  	if (unlikely(port_status & VSC_SATA_INT_ERROR)) {
  		vsc_error_intr(port_status, ap);
  		return;
  	}

  	qc = ata_qc_from_tag(ap, ap->link.active_tag);

  	if (qc && likely(!(qc->tf.flags & ATA_TFLAG_POLLING)))

  		handled = ata_bmdma_port_intr(ap, qc);

  
  	/* We received an interrupt during a polled command,
  	 * or some other spurious condition.  Interrupt reporting
  	 * with this hardware is fairly reliable so it is safe to
  	 * simply clear the interrupt
  	 */
  	if (unlikely(!handled))

  		ap->ops->sff_check_status(ap);

  }

  
  /*
   * vsc_sata_interrupt
   *

   * Read the interrupt register and process for the devices that have
   * them pending.

   */

  static irqreturn_t vsc_sata_interrupt(int irq, void *dev_instance)

  {

  	struct ata_host *host = dev_instance;

  	unsigned int i;
  	unsigned int handled = 0;

  	u32 status;

  	status = readl(host->iomap[VSC_MMIO_BAR] + VSC_SATA_INT_STAT_OFFSET);

  	if (unlikely(status == 0xffffffff || status == 0)) {
  		if (status)

  			dev_err(host->dev,
  				": IRQ status == 0xffffffff, PCI fault or device removal?
  ");

  		goto out;
  	}

  	spin_lock(&host->lock);

  	for (i = 0; i < host->n_ports; i++) {
  		u8 port_status = (status >> (8 * i)) & 0xff;
  		if (port_status) {

  			vsc_port_intr(port_status, host->ports[i]);
  			handled++;

  		}
  	}

  	spin_unlock(&host->lock);

  out:

  	return IRQ_RETVAL(handled);
  }

  static struct scsi_host_template vsc_sata_sht = {

  	ATA_BMDMA_SHT(DRV_NAME),

  };

  static struct ata_port_operations vsc_sata_ops = {
  	.inherits		= &ata_bmdma_port_ops,

  	/* The IRQ handling is not quite standard SFF behaviour so we
  	   cannot use the default lost interrupt handler */
  	.lost_interrupt		= ATA_OP_NULL,

  	.sff_tf_load		= vsc_sata_tf_load,
  	.sff_tf_read		= vsc_sata_tf_read,

  	.freeze			= vsc_freeze,
  	.thaw			= vsc_thaw,

  	.scr_read		= vsc_sata_scr_read,
  	.scr_write		= vsc_sata_scr_write,

  };

  static void __devinit vsc_sata_setup_port(struct ata_ioports *port,
  					  void __iomem *base)

  {
  	port->cmd_addr		= base + VSC_SATA_TF_CMD_OFFSET;
  	port->data_addr		= base + VSC_SATA_TF_DATA_OFFSET;
  	port->error_addr	= base + VSC_SATA_TF_ERROR_OFFSET;
  	port->feature_addr	= base + VSC_SATA_TF_FEATURE_OFFSET;
  	port->nsect_addr	= base + VSC_SATA_TF_NSECT_OFFSET;
  	port->lbal_addr		= base + VSC_SATA_TF_LBAL_OFFSET;
  	port->lbam_addr		= base + VSC_SATA_TF_LBAM_OFFSET;
  	port->lbah_addr		= base + VSC_SATA_TF_LBAH_OFFSET;
  	port->device_addr	= base + VSC_SATA_TF_DEVICE_OFFSET;
  	port->status_addr	= base + VSC_SATA_TF_STATUS_OFFSET;
  	port->command_addr	= base + VSC_SATA_TF_COMMAND_OFFSET;
  	port->altstatus_addr	= base + VSC_SATA_TF_ALTSTATUS_OFFSET;
  	port->ctl_addr		= base + VSC_SATA_TF_CTL_OFFSET;
  	port->bmdma_addr	= base + VSC_SATA_DMA_CMD_OFFSET;
  	port->scr_addr		= base + VSC_SATA_SCR_STATUS_OFFSET;

  	writel(0, base + VSC_SATA_UP_DESCRIPTOR_OFFSET);
  	writel(0, base + VSC_SATA_UP_DATA_BUFFER_OFFSET);

  }

  static int __devinit vsc_sata_init_one(struct pci_dev *pdev,
  				       const struct pci_device_id *ent)

  {

  	static const struct ata_port_info pi = {

  		.flags		= ATA_FLAG_SATA,

  		.pio_mask	= ATA_PIO4,
  		.mwdma_mask	= ATA_MWDMA2,

  		.udma_mask	= ATA_UDMA6,

  		.port_ops	= &vsc_sata_ops,
  	};
  	const struct ata_port_info *ppi[] = { &pi, NULL };

  	struct ata_host *host;

  	void __iomem *mmio_base;

  	int i, rc;

  	u8 cls;

  	ata_print_version_once(&pdev->dev, DRV_VERSION);

  	/* allocate host */
  	host = ata_host_alloc_pinfo(&pdev->dev, ppi, 4);
  	if (!host)
  		return -ENOMEM;

  	rc = pcim_enable_device(pdev);

  	if (rc)
  		return rc;

  	/* check if we have needed resource mapped */

  	if (pci_resource_len(pdev, 0) == 0)
  		return -ENODEV;

  	/* map IO regions and initialize host accordingly */

  	rc = pcim_iomap_regions(pdev, 1 << VSC_MMIO_BAR, DRV_NAME);
  	if (rc == -EBUSY)

  		pcim_pin_device(pdev);

  	if (rc)

  		return rc;

  	host->iomap = pcim_iomap_table(pdev);
  
  	mmio_base = host->iomap[VSC_MMIO_BAR];

  	for (i = 0; i < host->n_ports; i++) {
  		struct ata_port *ap = host->ports[i];
  		unsigned int offset = (i + 1) * VSC_SATA_PORT_OFFSET;
  
  		vsc_sata_setup_port(&ap->ioaddr, mmio_base + offset);
  
  		ata_port_pbar_desc(ap, VSC_MMIO_BAR, -1, "mmio");
  		ata_port_pbar_desc(ap, VSC_MMIO_BAR, offset, "port");
  	}

  
  	/*
  	 * Use 32 bit DMA mask, because 64 bit address support is poor.
  	 */

  	rc = pci_set_dma_mask(pdev, DMA_BIT_MASK(32));

  	if (rc)

  		return rc;

  	rc = pci_set_consistent_dma_mask(pdev, DMA_BIT_MASK(32));

  	if (rc)

  		return rc;

  	/*

  	 * Due to a bug in the chip, the default cache line size can't be
  	 * used (unless the default is non-zero).

  	 */

  	pci_read_config_byte(pdev, PCI_CACHE_LINE_SIZE, &cls);
  	if (cls == 0x00)
  		pci_write_config_byte(pdev, PCI_CACHE_LINE_SIZE, 0x80);

  	if (pci_enable_msi(pdev) == 0)

  		pci_intx(pdev, 0);

  	/*

  	 * Config offset 0x98 is "Extended Control and Status Register 0"
  	 * Default value is (1 << 28).  All bits except bit 28 are reserved in
  	 * DPA mode.  If bit 28 is set, LED 0 reflects all ports' activity.
  	 * If bit 28 is clear, each port has its own LED.
  	 */
  	pci_write_config_dword(pdev, 0x98, 0);

  	pci_set_master(pdev);
  	return ata_host_activate(host, pdev->irq, vsc_sata_interrupt,
  				 IRQF_SHARED, &vsc_sata_sht);

  }

  static const struct pci_device_id vsc_sata_pci_tbl[] = {

  	{ PCI_VENDOR_ID_VITESSE, 0x7174,

  	  PCI_ANY_ID, PCI_ANY_ID, 0x10600, 0xFFFFFF, 0 },

  	{ PCI_VENDOR_ID_INTEL, 0x3200,

  	  PCI_ANY_ID, PCI_ANY_ID, 0x10600, 0xFFFFFF, 0 },

  	{ }	/* terminate list */

  };

  static struct pci_driver vsc_sata_pci_driver = {
  	.name			= DRV_NAME,
  	.id_table		= vsc_sata_pci_tbl,
  	.probe			= vsc_sata_init_one,
  	.remove			= ata_pci_remove_one,
  };

  static int __init vsc_sata_init(void)
  {

  	return pci_register_driver(&vsc_sata_pci_driver);

  }

  static void __exit vsc_sata_exit(void)
  {
  	pci_unregister_driver(&vsc_sata_pci_driver);
  }

  MODULE_AUTHOR("Jeremy Higdon");
  MODULE_DESCRIPTION("low-level driver for Vitesse VSC7174 SATA controller");
  MODULE_LICENSE("GPL");
  MODULE_DEVICE_TABLE(pci, vsc_sata_pci_tbl);
  MODULE_VERSION(DRV_VERSION);
  
  module_init(vsc_sata_init);
  module_exit(vsc_sata_exit);