// SPDX-License-Identifier: GPL-2.0-only

  /*
   *    pata_efar.c - EFAR PIIX clone controller driver
   *

   *	(C) 2005 Red Hat

   *	(C) 2009-2010 Bartlomiej Zolnierkiewicz

   *
   *    Some parts based on ata_piix.c by Jeff Garzik and others.
   *
   *    The EFAR is a PIIX4 clone with UDMA66 support. Unlike the later
   *    Intel ICH controllers the EFAR widened the UDMA mode register bits
   *    and doesn't require the funky clock selection.
   */
  
  #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_host.h>
  #include <linux/libata.h>
  #include <linux/ata.h>
  
  #define DRV_NAME	"pata_efar"

  #define DRV_VERSION	"0.4.5"

  
  /**

   *	efar_pre_reset	-	Enable bits

   *	@link: ATA link

   *	@deadline: deadline jiffies for the operation

   *
   *	Perform cable detection for the EFAR ATA interface. This is
   *	different to the PIIX arrangement
   */

  static int efar_pre_reset(struct ata_link *link, unsigned long deadline)

  {
  	static const struct pci_bits efar_enable_bits[] = {
  		{ 0x41U, 1U, 0x80UL, 0x80UL },	/* port 0 */
  		{ 0x43U, 1U, 0x80UL, 0x80UL },	/* port 1 */
  	};

  	struct ata_port *ap = link->ap;

  	struct pci_dev *pdev = to_pci_dev(ap->host->dev);

  	if (!pci_test_config_bits(pdev, &efar_enable_bits[ap->port_no]))
  		return -ENOENT;

  	return ata_sff_prereset(link, deadline);

  }
  
  /**

   *	efar_cable_detect	-	check for 40/80 pin
   *	@ap: Port
   *
   *	Perform cable detection for the EFAR ATA interface. This is
   *	different to the PIIX arrangement
   */
  
  static int efar_cable_detect(struct ata_port *ap)
  {
  	struct pci_dev *pdev = to_pci_dev(ap->host->dev);
  	u8 tmp;
  
  	pci_read_config_byte(pdev, 0x47, &tmp);
  	if (tmp & (2 >> ap->port_no))
  		return ATA_CBL_PATA40;
  	return ATA_CBL_PATA80;
  }

  static DEFINE_SPINLOCK(efar_lock);

  /**

   *	efar_set_piomode - Initialize host controller PATA PIO timings
   *	@ap: Port whose timings we are configuring

   *	@adev: Device to program

   *
   *	Set PIO mode for device, in host controller PCI config space.
   *
   *	LOCKING:
   *	None (inherited from caller).
   */
  
  static void efar_set_piomode (struct ata_port *ap, struct ata_device *adev)
  {
  	unsigned int pio	= adev->pio_mode - XFER_PIO_0;
  	struct pci_dev *dev	= to_pci_dev(ap->host->dev);

  	unsigned int master_port = ap->port_no ? 0x42 : 0x40;

  	unsigned long flags;

  	u16 master_data;

  	u8 udma_enable;

  	int control = 0;
  
  	/*
  	 *	See Intel Document 298600-004 for the timing programing rules
  	 *	for PIIX/ICH. The EFAR is a clone so very similar
  	 */
  
  	static const	 /* ISP  RTC */
  	u8 timings[][2]	= { { 0, 0 },
  			    { 0, 0 },
  			    { 1, 0 },
  			    { 2, 1 },
  			    { 2, 3 }, };

  	if (pio > 1)
  		control |= 1;	/* TIME */

  	if (ata_pio_need_iordy(adev))	/* PIO 3/4 require IORDY */

  		control |= 2;	/* IE */
  	/* Intel specifies that the prefetch/posting is for disk only */

  	if (adev->class == ATA_DEV_ATA)

  		control |= 4;	/* PPE */

  	spin_lock_irqsave(&efar_lock, flags);

  	pci_read_config_word(dev, master_port, &master_data);

  	/* Set PPE, IE, and TIME as appropriate */

  	if (adev->devno == 0) {

  		master_data &= 0xCCF0;
  		master_data |= control;
  		master_data |= (timings[pio][0] << 12) |

  			(timings[pio][1] << 8);
  	} else {
  		int shift = 4 * ap->port_no;
  		u8 slave_data;

  		master_data &= 0xFF0F;
  		master_data |= (control << 4);

  		/* Slave timing in separate register */

  		pci_read_config_byte(dev, 0x44, &slave_data);

  		slave_data &= ap->port_no ? 0x0F : 0xF0;

  		slave_data |= ((timings[pio][0] << 2) | timings[pio][1]) << shift;
  		pci_write_config_byte(dev, 0x44, slave_data);
  	}

  	master_data |= 0x4000;	/* Ensure SITRE is set */
  	pci_write_config_word(dev, master_port, master_data);

  
  	pci_read_config_byte(dev, 0x48, &udma_enable);
  	udma_enable &= ~(1 << (2 * ap->port_no + adev->devno));
  	pci_write_config_byte(dev, 0x48, udma_enable);
  	spin_unlock_irqrestore(&efar_lock, flags);

  }
  
  /**
   *	efar_set_dmamode - Initialize host controller PATA DMA timings
   *	@ap: Port whose timings we are configuring
   *	@adev: Device to program
   *
   *	Set UDMA/MWDMA mode for device, in host controller PCI config space.
   *
   *	LOCKING:
   *	None (inherited from caller).
   */
  
  static void efar_set_dmamode (struct ata_port *ap, struct ata_device *adev)
  {
  	struct pci_dev *dev	= to_pci_dev(ap->host->dev);
  	u8 master_port		= ap->port_no ? 0x42 : 0x40;
  	u16 master_data;
  	u8 speed		= adev->dma_mode;
  	int devid		= adev->devno + 2 * ap->port_no;

  	unsigned long flags;

  	u8 udma_enable;
  
  	static const	 /* ISP  RTC */
  	u8 timings[][2]	= { { 0, 0 },
  			    { 0, 0 },
  			    { 1, 0 },
  			    { 2, 1 },
  			    { 2, 3 }, };

  	spin_lock_irqsave(&efar_lock, flags);

  	pci_read_config_word(dev, master_port, &master_data);
  	pci_read_config_byte(dev, 0x48, &udma_enable);
  
  	if (speed >= XFER_UDMA_0) {
  		unsigned int udma	= adev->dma_mode - XFER_UDMA_0;
  		u16 udma_timing;
  
  		udma_enable |= (1 << devid);
  
  		/* Load the UDMA mode number */
  		pci_read_config_word(dev, 0x4A, &udma_timing);
  		udma_timing &= ~(7 << (4 * devid));
  		udma_timing |= udma << (4 * devid);
  		pci_write_config_word(dev, 0x4A, udma_timing);
  	} else {
  		/*
  		 * MWDMA is driven by the PIO timings. We must also enable
  		 * IORDY unconditionally along with TIME1. PPE has already
  		 * been set when the PIO timing was set.
  		 */
  		unsigned int mwdma	= adev->dma_mode - XFER_MW_DMA_0;
  		unsigned int control;
  		u8 slave_data;
  		const unsigned int needed_pio[3] = {
  			XFER_PIO_0, XFER_PIO_3, XFER_PIO_4
  		};
  		int pio = needed_pio[mwdma] - XFER_PIO_0;
  
  		control = 3;	/* IORDY|TIME1 */
  
  		/* If the drive MWDMA is faster than it can do PIO then
  		   we must force PIO into PIO0 */
  
  		if (adev->pio_mode < needed_pio[mwdma])
  			/* Enable DMA timing only */
  			control |= 8;	/* PIO cycles in PIO0 */
  
  		if (adev->devno) {	/* Slave */
  			master_data &= 0xFF4F;  /* Mask out IORDY|TIME1|DMAONLY */
  			master_data |= control << 4;
  			pci_read_config_byte(dev, 0x44, &slave_data);

  			slave_data &= ap->port_no ? 0x0F : 0xF0;

  			/* Load the matching timing */
  			slave_data |= ((timings[pio][0] << 2) | timings[pio][1]) << (ap->port_no ? 4 : 0);
  			pci_write_config_byte(dev, 0x44, slave_data);
  		} else { 	/* Master */
  			master_data &= 0xCCF4;	/* Mask out IORDY|TIME1|DMAONLY
  						   and master timing bits */
  			master_data |= control;
  			master_data |=
  				(timings[pio][0] << 12) |
  				(timings[pio][1] << 8);
  		}
  		udma_enable &= ~(1 << devid);
  		pci_write_config_word(dev, master_port, master_data);
  	}
  	pci_write_config_byte(dev, 0x48, udma_enable);

  	spin_unlock_irqrestore(&efar_lock, flags);

  }
  
  static struct scsi_host_template efar_sht = {

  	ATA_BMDMA_SHT(DRV_NAME),

  };

  static struct ata_port_operations efar_ops = {
  	.inherits		= &ata_bmdma_port_ops,
  	.cable_detect		= efar_cable_detect,

  	.set_piomode		= efar_set_piomode,
  	.set_dmamode		= efar_set_dmamode,

  	.prereset		= efar_pre_reset,

  };
  
  
  /**
   *	efar_init_one - Register EFAR ATA PCI device with kernel services
   *	@pdev: PCI device to register
   *	@ent: Entry in efar_pci_tbl matching with @pdev
   *
   *	Called from kernel PCI layer.
   *
   *	LOCKING:
   *	Inherited from PCI layer (may sleep).
   *
   *	RETURNS:
   *	Zero on success, or -ERRNO value.
   */
  
  static int efar_init_one (struct pci_dev *pdev, const struct pci_device_id *ent)
  {

  	static const struct ata_port_info info = {

  		.flags		= ATA_FLAG_SLAVE_POSS,

  		.pio_mask	= ATA_PIO4,

  		.mwdma_mask	= ATA_MWDMA12_ONLY,

  		.udma_mask 	= ATA_UDMA4,

  		.port_ops	= &efar_ops,
  	};

  	const struct ata_port_info *ppi[] = { &info, &info };

  	ata_print_version_once(&pdev->dev, DRV_VERSION);

  	return ata_pci_bmdma_init_one(pdev, ppi, &efar_sht, NULL,
  				      ATA_HOST_PARALLEL_SCAN);

  }
  
  static const struct pci_device_id efar_pci_tbl[] = {

  	{ PCI_VDEVICE(EFAR, 0x9130), },

  	{ }	/* terminate list */
  };
  
  static struct pci_driver efar_pci_driver = {
  	.name			= DRV_NAME,
  	.id_table		= efar_pci_tbl,
  	.probe			= efar_init_one,
  	.remove			= ata_pci_remove_one,

  #ifdef CONFIG_PM_SLEEP

  	.suspend		= ata_pci_device_suspend,
  	.resume			= ata_pci_device_resume,

  #endif

  };

  module_pci_driver(efar_pci_driver);

  
  MODULE_AUTHOR("Alan Cox");
  MODULE_DESCRIPTION("SCSI low-level driver for EFAR PIIX clones");
  MODULE_LICENSE("GPL");
  MODULE_DEVICE_TABLE(pci, efar_pci_tbl);
  MODULE_VERSION(DRV_VERSION);