/*
   *  Copyright (C) 1998-1999 Andrzej Krzysztofowicz, Author and Maintainer
   *  Copyright (C) 1998-2000 Andre Hedrick <andre@linux-ide.org>
   *  Copyright (C) 2003 Red Hat
   *  Copyright (C) 2006-2007 MontaVista Software, Inc. <source@mvista.com>
   *
   *  May be copied or modified under the terms of the GNU General Public License
   *
   * Documentation:
   *
   *	Publicly available from Intel web site. Errata documentation
   * is also publicly available. As an aide to anyone hacking on this
   * driver the list of errata that are relevant is below.going back to
   * PIIX4. Older device documentation is now a bit tricky to find.
   *
   * Errata of note:
   *
   * Unfixable
   *	PIIX4    errata #9	- Only on ultra obscure hw
   *	ICH3	 errata #13     - Not observed to affect real hw
   *				  by Intel
   *
   * Things we must deal with
   *	PIIX4	errata #10	- BM IDE hang with non UDMA
   *				  (must stop/start dma to recover)
   *	440MX   errata #15	- As PIIX4 errata #10
   *	PIIX4	errata #15	- Must not read control registers
   * 				  during a PIO transfer
   *	440MX   errata #13	- As PIIX4 errata #15
   *	ICH2	errata #21	- DMA mode 0 doesn't work right
   *	ICH0/1  errata #55	- As ICH2 errata #21
   *	ICH2	spec c #9	- Extra operations needed to handle
   *				  drive hotswap [NOT YET SUPPORTED]
   *	ICH2    spec c #20	- IDE PRD must not cross a 64K boundary
   *				  and must be dword aligned
   *	ICH2    spec c #24	- UDMA mode 4,5 t85/86 should be 6ns not 3.3
   *
   * Should have been BIOS fixed:
   *	450NX:	errata #19	- DMA hangs on old 450NX
   *	450NX:  errata #20	- DMA hangs on old 450NX
   *	450NX:  errata #25	- Corruption with DMA on old 450NX
   *	ICH3    errata #15      - IDE deadlock under high load
   *				  (BIOS must set dev 31 fn 0 bit 23)
   *	ICH3	errata #18	- Don't use native mode
   */
  
  #include <linux/types.h>
  #include <linux/module.h>
  #include <linux/kernel.h>
  #include <linux/pci.h>
  #include <linux/ide.h>
  #include <linux/init.h>
  
  #include <asm/io.h>
  
  #define DRV_NAME "piix"
  
  static int no_piix_dma;
  
  /**
   *	piix_set_pio_mode	-	set host controller for PIO mode
   *	@port: port
   *	@drive: drive
   *
   *	Set the interface PIO mode based upon the settings done by AMI BIOS.
   */
  
  static void piix_set_pio_mode(ide_hwif_t *hwif, ide_drive_t *drive)
  {
  	struct pci_dev *dev	= to_pci_dev(hwif->dev);
  	int is_slave		= drive->dn & 1;
  	int master_port		= hwif->channel ? 0x42 : 0x40;
  	int slave_port		= 0x44;
  	unsigned long flags;
  	u16 master_data;
  	u8 slave_data;
  	static DEFINE_SPINLOCK(tune_lock);
  	int control = 0;
  	const u8 pio = drive->pio_mode - XFER_PIO_0;
  
  				     /* ISP  RTC */
  	static const u8 timings[][2]= {
  					{ 0, 0 },
  					{ 0, 0 },
  					{ 1, 0 },
  					{ 2, 1 },
  					{ 2, 3 }, };
  
  	/*
  	 * Master vs slave is synchronized above us but the slave register is
  	 * shared by the two hwifs so the corner case of two slave timeouts in
  	 * parallel must be locked.
  	 */
  	spin_lock_irqsave(&tune_lock, flags);
  	pci_read_config_word(dev, master_port, &master_data);
  
  	if (pio > 1)
  		control |= 1;	/* Programmable timing on */
  	if (drive->media == ide_disk)
  		control |= 4;	/* Prefetch, post write */
  	if (ide_pio_need_iordy(drive, pio))
  		control |= 2;	/* IORDY */
  	if (is_slave) {
  		master_data |=  0x4000;
  		master_data &= ~0x0070;
  		if (pio > 1) {
  			/* Set PPE, IE and TIME */
  			master_data |= control << 4;
  		}
  		pci_read_config_byte(dev, slave_port, &slave_data);
  		slave_data &= hwif->channel ? 0x0f : 0xf0;
  		slave_data |= ((timings[pio][0] << 2) | timings[pio][1]) <<
  			       (hwif->channel ? 4 : 0);
  	} else {
  		master_data &= ~0x3307;
  		if (pio > 1) {
  			/* enable PPE, IE and TIME */
  			master_data |= control;
  		}
  		master_data |= (timings[pio][0] << 12) | (timings[pio][1] << 8);
  	}
  	pci_write_config_word(dev, master_port, master_data);
  	if (is_slave)
  		pci_write_config_byte(dev, slave_port, slave_data);
  	spin_unlock_irqrestore(&tune_lock, flags);
  }
  
  /**
   *	piix_set_dma_mode	-	set host controller for DMA mode
   *	@hwif: port
   *	@drive: drive
   *
   *	Set a PIIX host controller to the desired DMA mode.  This involves
   *	programming the right timing data into the PCI configuration space.
   */
  
  static void piix_set_dma_mode(ide_hwif_t *hwif, ide_drive_t *drive)
  {
  	struct pci_dev *dev	= to_pci_dev(hwif->dev);
  	u8 maslave		= hwif->channel ? 0x42 : 0x40;
  	int a_speed		= 3 << (drive->dn * 4);
  	int u_flag		= 1 << drive->dn;
  	int v_flag		= 0x01 << drive->dn;
  	int w_flag		= 0x10 << drive->dn;
  	int u_speed		= 0;
  	int			sitre;
  	u16			reg4042, reg4a;
  	u8			reg48, reg54, reg55;
  	const u8 speed		= drive->dma_mode;
  
  	pci_read_config_word(dev, maslave, &reg4042);
  	sitre = (reg4042 & 0x4000) ? 1 : 0;
  	pci_read_config_byte(dev, 0x48, &reg48);
  	pci_read_config_word(dev, 0x4a, &reg4a);
  	pci_read_config_byte(dev, 0x54, &reg54);
  	pci_read_config_byte(dev, 0x55, &reg55);
  
  	if (speed >= XFER_UDMA_0) {
  		u8 udma = speed - XFER_UDMA_0;
  
  		u_speed = min_t(u8, 2 - (udma & 1), udma) << (drive->dn * 4);
  
  		if (!(reg48 & u_flag))
  			pci_write_config_byte(dev, 0x48, reg48 | u_flag);
  		if (speed == XFER_UDMA_5) {
  			pci_write_config_byte(dev, 0x55, (u8) reg55|w_flag);
  		} else {
  			pci_write_config_byte(dev, 0x55, (u8) reg55 & ~w_flag);
  		}
  		if ((reg4a & a_speed) != u_speed)
  			pci_write_config_word(dev, 0x4a, (reg4a & ~a_speed) | u_speed);
  		if (speed > XFER_UDMA_2) {
  			if (!(reg54 & v_flag))
  				pci_write_config_byte(dev, 0x54, reg54 | v_flag);
  		} else
  			pci_write_config_byte(dev, 0x54, reg54 & ~v_flag);
  	} else {
  		const u8 mwdma_to_pio[] = { 0, 3, 4 };
  
  		if (reg48 & u_flag)
  			pci_write_config_byte(dev, 0x48, reg48 & ~u_flag);
  		if (reg4a & a_speed)
  			pci_write_config_word(dev, 0x4a, reg4a & ~a_speed);
  		if (reg54 & v_flag)
  			pci_write_config_byte(dev, 0x54, reg54 & ~v_flag);
  		if (reg55 & w_flag)
  			pci_write_config_byte(dev, 0x55, (u8) reg55 & ~w_flag);
  
  		if (speed >= XFER_MW_DMA_0)
  			drive->pio_mode =
  				mwdma_to_pio[speed - XFER_MW_DMA_0] + XFER_PIO_0;
  		else
  			drive->pio_mode = XFER_PIO_2; /* for SWDMA2 */
  
  		piix_set_pio_mode(hwif, drive);
  	}
  }
  
  /**
   *	init_chipset_ich	-	set up the ICH chipset
   *	@dev: PCI device to set up
   *
   *	Initialize the PCI device as required.  For the ICH this turns
   *	out to be nice and simple.
   */
  
  static int init_chipset_ich(struct pci_dev *dev)
  {
  	u32 extra = 0;
  
  	pci_read_config_dword(dev, 0x54, &extra);
  	pci_write_config_dword(dev, 0x54, extra | 0x400);
  
  	return 0;
  }
  
  /**
   *	ich_clear_irq	-	clear BMDMA status
   *	@drive: IDE drive
   *
   *	ICHx contollers set DMA INTR no matter DMA or PIO.
   *	BMDMA status might need to be cleared even for
   *	PIO interrupts to prevent spurious/lost IRQ.
   */
  static void ich_clear_irq(ide_drive_t *drive)
  {
  	ide_hwif_t *hwif = drive->hwif;
  	u8 dma_stat;
  
  	/*
  	 * ide_dma_end() needs BMDMA status for error checking.
  	 * So, skip clearing BMDMA status here and leave it
  	 * to ide_dma_end() if this is DMA interrupt.
  	 */
  	if (drive->waiting_for_dma || hwif->dma_base == 0)
  		return;
  
  	/* clear the INTR & ERROR bits */
  	dma_stat = inb(hwif->dma_base + ATA_DMA_STATUS);
  	/* Should we force the bit as well ? */
  	outb(dma_stat, hwif->dma_base + ATA_DMA_STATUS);
  }
  
  struct ich_laptop {
  	u16 device;
  	u16 subvendor;
  	u16 subdevice;
  };
  
  /*
   *	List of laptops that use short cables rather than 80 wire
   */
  
  static const struct ich_laptop ich_laptop[] = {
  	/* devid, subvendor, subdev */
  	{ 0x27DF, 0x1025, 0x0102 },	/* ICH7 on Acer 5602aWLMi */
  	{ 0x27DF, 0x0005, 0x0280 },	/* ICH7 on Acer 5602WLMi */
  	{ 0x27DF, 0x1025, 0x0110 },	/* ICH7 on Acer 3682WLMi */
  	{ 0x27DF, 0x1043, 0x1267 },	/* ICH7 on Asus W5F */
  	{ 0x27DF, 0x103C, 0x30A1 },	/* ICH7 on HP Compaq nc2400 */
  	{ 0x27DF, 0x1071, 0xD221 },	/* ICH7 on Hercules EC-900 */
  	{ 0x24CA, 0x1025, 0x0061 },	/* ICH4 on Acer Aspire 2023WLMi */
  	{ 0x24CA, 0x1025, 0x003d },	/* ICH4 on ACER TM290 */
  	{ 0x266F, 0x1025, 0x0066 },	/* ICH6 on ACER Aspire 1694WLMi */
  	{ 0x2653, 0x1043, 0x82D8 },	/* ICH6M on Asus Eee 701 */
  	{ 0x27df, 0x104d, 0x900e },	/* ICH7 on Sony TZ-90 */
  	/* end marker */
  	{ 0, }
  };
  
  static u8 piix_cable_detect(ide_hwif_t *hwif)
  {
  	struct pci_dev *pdev = to_pci_dev(hwif->dev);
  	const struct ich_laptop *lap = &ich_laptop[0];
  	u8 reg54h = 0, mask = hwif->channel ? 0xc0 : 0x30;
  
  	/* check for specials */
  	while (lap->device) {
  		if (lap->device == pdev->device &&
  		    lap->subvendor == pdev->subsystem_vendor &&
  		    lap->subdevice == pdev->subsystem_device) {
  			return ATA_CBL_PATA40_SHORT;
  		}
  		lap++;
  	}
  
  	pci_read_config_byte(pdev, 0x54, &reg54h);
  
  	return (reg54h & mask) ? ATA_CBL_PATA80 : ATA_CBL_PATA40;
  }
  
  /**
   *	init_hwif_piix		-	fill in the hwif for the PIIX
   *	@hwif: IDE interface
   *
   *	Set up the ide_hwif_t for the PIIX interface according to the
   *	capabilities of the hardware.
   */
  
  static void init_hwif_piix(ide_hwif_t *hwif)
  {
  	if (!hwif->dma_base)
  		return;
  
  	if (no_piix_dma)
  		hwif->ultra_mask = hwif->mwdma_mask = hwif->swdma_mask = 0;
  }
  
  static const struct ide_port_ops piix_port_ops = {
  	.set_pio_mode		= piix_set_pio_mode,
  	.set_dma_mode		= piix_set_dma_mode,
  	.cable_detect		= piix_cable_detect,
  };
  
  static const struct ide_port_ops ich_port_ops = {
  	.set_pio_mode		= piix_set_pio_mode,
  	.set_dma_mode		= piix_set_dma_mode,
  	.clear_irq		= ich_clear_irq,
  	.cable_detect		= piix_cable_detect,
  };
  
  #define DECLARE_PIIX_DEV(udma) \
  	{						\
  		.name		= DRV_NAME,		\
  		.init_hwif	= init_hwif_piix,	\
  		.enablebits	= {{0x41,0x80,0x80}, {0x43,0x80,0x80}}, \
  		.port_ops	= &piix_port_ops,	\
  		.pio_mask	= ATA_PIO4,		\
  		.swdma_mask	= ATA_SWDMA2_ONLY,	\
  		.mwdma_mask	= ATA_MWDMA12_ONLY,	\
  		.udma_mask	= udma,			\
  	}
  
  #define DECLARE_ICH_DEV(mwdma, udma) \
  	{ \
  		.name		= DRV_NAME, \
  		.init_chipset	= init_chipset_ich, \
  		.init_hwif	= init_hwif_piix, \
  		.enablebits	= {{0x41,0x80,0x80}, {0x43,0x80,0x80}}, \
  		.port_ops	= &ich_port_ops, \
  		.pio_mask	= ATA_PIO4, \
  		.swdma_mask	= ATA_SWDMA2_ONLY, \
  		.mwdma_mask	= mwdma, \
  		.udma_mask	= udma, \
  	}
  
  static const struct ide_port_info piix_pci_info[] = {
  	/* 0: MPIIX */
  	{	/*
  		 * MPIIX actually has only a single IDE channel mapped to
  		 * the primary or secondary ports depending on the value
  		 * of the bit 14 of the IDETIM register at offset 0x6c
  		 */
  		.name		= DRV_NAME,
  		.enablebits	= {{0x6d,0xc0,0x80}, {0x6d,0xc0,0xc0}},
  		.host_flags	= IDE_HFLAG_ISA_PORTS | IDE_HFLAG_NO_DMA,
  		.pio_mask	= ATA_PIO4,
  		/* This is a painful system best to let it self tune for now */
  	},
  	/* 1: PIIXa/PIIXb/PIIX3 */
  	DECLARE_PIIX_DEV(0x00), /* no udma */
  	/* 2: PIIX4 */
  	DECLARE_PIIX_DEV(ATA_UDMA2),
  	/* 3: ICH0 */
  	DECLARE_ICH_DEV(ATA_MWDMA12_ONLY, ATA_UDMA2),
  	/* 4: ICH */
  	DECLARE_ICH_DEV(ATA_MWDMA12_ONLY, ATA_UDMA4),
  	/* 5: PIIX4 */
  	DECLARE_PIIX_DEV(ATA_UDMA4),
  	/* 6: ICH[2-6]/ICH[2-3]M/C-ICH/ICH5-SATA/ESB2/ICH8M */
  	DECLARE_ICH_DEV(ATA_MWDMA12_ONLY, ATA_UDMA5),
  	/* 7: ICH7/7-R, no MWDMA1 */
  	DECLARE_ICH_DEV(ATA_MWDMA2_ONLY, ATA_UDMA5),
  };
  
  /**
   *	piix_init_one	-	called when a PIIX is found
   *	@dev: the piix device
   *	@id: the matching pci id
   *
   *	Called when the PCI registration layer (or the IDE initialization)
   *	finds a device matching our IDE device tables.
   */
   
  static int piix_init_one(struct pci_dev *dev, const struct pci_device_id *id)
  {
  	return ide_pci_init_one(dev, &piix_pci_info[id->driver_data], NULL);
  }
  
  /**
   *	piix_check_450nx	-	Check for problem 450NX setup
   *	
   *	Check for the present of 450NX errata #19 and errata #25. If
   *	they are found, disable use of DMA IDE
   */
  
  static void piix_check_450nx(void)
  {
  	struct pci_dev *pdev = NULL;
  	u16 cfg;
  	while((pdev=pci_get_device(PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_82454NX, pdev))!=NULL)
  	{
  		/* Look for 450NX PXB. Check for problem configurations
  		   A PCI quirk checks bit 6 already */
  		pci_read_config_word(pdev, 0x41, &cfg);
  		/* Only on the original revision: IDE DMA can hang */
  		if (pdev->revision == 0x00)
  			no_piix_dma = 1;
  		/* On all revisions below 5 PXB bus lock must be disabled for IDE */
  		else if (cfg & (1<<14) && pdev->revision < 5)
  			no_piix_dma = 2;
  	}
  	if(no_piix_dma)
  		printk(KERN_WARNING DRV_NAME ": 450NX errata present, disabling IDE DMA.
  ");
  	if(no_piix_dma == 2)
  		printk(KERN_WARNING DRV_NAME ": A BIOS update may resolve this.
  ");
  }		
  
  static const struct pci_device_id piix_pci_tbl[] = {
  	{ PCI_VDEVICE(INTEL, PCI_DEVICE_ID_INTEL_82371FB_0),  1 },
  	{ PCI_VDEVICE(INTEL, PCI_DEVICE_ID_INTEL_82371FB_1),  1 },
  	{ PCI_VDEVICE(INTEL, PCI_DEVICE_ID_INTEL_82371MX),    0 },
  	{ PCI_VDEVICE(INTEL, PCI_DEVICE_ID_INTEL_82371SB_1),  1 },
  	{ PCI_VDEVICE(INTEL, PCI_DEVICE_ID_INTEL_82371AB),    2 },
  	{ PCI_VDEVICE(INTEL, PCI_DEVICE_ID_INTEL_82801AB_1),  3 },
  	{ PCI_VDEVICE(INTEL, PCI_DEVICE_ID_INTEL_82443MX_1),  2 },
  	{ PCI_VDEVICE(INTEL, PCI_DEVICE_ID_INTEL_82801AA_1),  4 },
  	{ PCI_VDEVICE(INTEL, PCI_DEVICE_ID_INTEL_82372FB_1),  5 },
  	{ PCI_VDEVICE(INTEL, PCI_DEVICE_ID_INTEL_82451NX),    2 },
  	{ PCI_VDEVICE(INTEL, PCI_DEVICE_ID_INTEL_82801BA_9),  6 },
  	{ PCI_VDEVICE(INTEL, PCI_DEVICE_ID_INTEL_82801BA_8),  6 },
  	{ PCI_VDEVICE(INTEL, PCI_DEVICE_ID_INTEL_82801CA_10), 6 },
  	{ PCI_VDEVICE(INTEL, PCI_DEVICE_ID_INTEL_82801CA_11), 6 },
  	{ PCI_VDEVICE(INTEL, PCI_DEVICE_ID_INTEL_82801DB_11), 6 },
  	{ PCI_VDEVICE(INTEL, PCI_DEVICE_ID_INTEL_82801EB_11), 6 },
  	{ PCI_VDEVICE(INTEL, PCI_DEVICE_ID_INTEL_82801E_11),  6 },
  	{ PCI_VDEVICE(INTEL, PCI_DEVICE_ID_INTEL_82801DB_10), 6 },
  #ifdef CONFIG_BLK_DEV_IDE_SATA
  	{ PCI_VDEVICE(INTEL, PCI_DEVICE_ID_INTEL_82801EB_1),  6 },
  #endif
  	{ PCI_VDEVICE(INTEL, PCI_DEVICE_ID_INTEL_ESB_2),      6 },
  	{ PCI_VDEVICE(INTEL, PCI_DEVICE_ID_INTEL_ICH6_19),    6 },
  	{ PCI_VDEVICE(INTEL, PCI_DEVICE_ID_INTEL_ICH7_21),    7 },
  	{ PCI_VDEVICE(INTEL, PCI_DEVICE_ID_INTEL_82801DB_1),  6 },
  	{ PCI_VDEVICE(INTEL, PCI_DEVICE_ID_INTEL_ESB2_18),    7 },
  	{ PCI_VDEVICE(INTEL, PCI_DEVICE_ID_INTEL_ICH8_6),     6 },
  	{ 0, },
  };
  MODULE_DEVICE_TABLE(pci, piix_pci_tbl);
  
  static struct pci_driver piix_pci_driver = {
  	.name		= "PIIX_IDE",
  	.id_table	= piix_pci_tbl,
  	.probe		= piix_init_one,
  	.remove		= ide_pci_remove,
  	.suspend	= ide_pci_suspend,
  	.resume		= ide_pci_resume,
  };
  
  static int __init piix_ide_init(void)
  {
  	piix_check_450nx();
  	return ide_pci_register_driver(&piix_pci_driver);
  }
  
  static void __exit piix_ide_exit(void)
  {
  	pci_unregister_driver(&piix_pci_driver);
  }
  
  module_init(piix_ide_init);
  module_exit(piix_ide_exit);
  
  MODULE_AUTHOR("Andre Hedrick, Andrzej Krzysztofowicz");
  MODULE_DESCRIPTION("PCI driver module for Intel PIIX IDE");
  MODULE_LICENSE("GPL");