/*
   * VIA IDE driver for Linux. Supported southbridges:
   *
   *   vt82c576, vt82c586, vt82c586a, vt82c586b, vt82c596a, vt82c596b,
   *   vt82c686, vt82c686a, vt82c686b, vt8231, vt8233, vt8233c, vt8233a,
   *   vt8235, vt8237, vt8237a
   *
   * Copyright (c) 2000-2002 Vojtech Pavlik
   * Copyright (c) 2007-2010 Bartlomiej Zolnierkiewicz
   *
   * Based on the work of:
   *	Michel Aubry
   *	Jeff Garzik
   *	Andre Hedrick
   *
   * Documentation:
   *	Obsolete device documentation publicly available from via.com.tw
   *	Current device documentation available under NDA only
   */
  
  /*
   * This program is free software; you can redistribute it and/or modify it
   * under the terms of the GNU General Public License version 2 as published by
   * the Free Software Foundation.
   */
  
  #include <linux/module.h>
  #include <linux/kernel.h>
  #include <linux/slab.h>
  #include <linux/pci.h>
  #include <linux/init.h>
  #include <linux/ide.h>
  #include <linux/dmi.h>
  
  #ifdef CONFIG_PPC_CHRP
  #include <asm/processor.h>
  #endif
  
  #define DRV_NAME "via82cxxx"
  
  #define VIA_IDE_ENABLE		0x40
  #define VIA_IDE_CONFIG		0x41
  #define VIA_FIFO_CONFIG		0x43
  #define VIA_MISC_1		0x44
  #define VIA_MISC_2		0x45
  #define VIA_MISC_3		0x46
  #define VIA_DRIVE_TIMING	0x48
  #define VIA_8BIT_TIMING		0x4e
  #define VIA_ADDRESS_SETUP	0x4c
  #define VIA_UDMA_TIMING		0x50
  
  #define VIA_BAD_PREQ		0x01 /* Crashes if PREQ# till DDACK# set */
  #define VIA_BAD_CLK66		0x02 /* 66 MHz clock doesn't work correctly */
  #define VIA_SET_FIFO		0x04 /* Needs to have FIFO split set */
  #define VIA_NO_UNMASK		0x08 /* Doesn't work with IRQ unmasking on */
  #define VIA_BAD_ID		0x10 /* Has wrong vendor ID (0x1107) */
  #define VIA_BAD_AST		0x20 /* Don't touch Address Setup Timing */
  #define VIA_SATA_PATA		0x80 /* SATA/PATA combined configuration */
  
  enum {
  	VIA_IDFLAG_SINGLE = (1 << 1), /* single channel controller */
  };
  
  /*
   * VIA SouthBridge chips.
   */
  
  static struct via_isa_bridge {
  	char *name;
  	u16 id;
  	u8 rev_min;
  	u8 rev_max;
  	u8 udma_mask;
  	u8 flags;
  } via_isa_bridges[] = {
  	{ "vx855",	PCI_DEVICE_ID_VIA_VX855,    0x00, 0x2f, ATA_UDMA6, VIA_BAD_AST | VIA_SATA_PATA },
  	{ "vx800",	PCI_DEVICE_ID_VIA_VX800,    0x00, 0x2f, ATA_UDMA6, VIA_BAD_AST | VIA_SATA_PATA },
  	{ "cx700",	PCI_DEVICE_ID_VIA_CX700,    0x00, 0x2f, ATA_UDMA6, VIA_BAD_AST | VIA_SATA_PATA },
  	{ "vt8261",	PCI_DEVICE_ID_VIA_8261,     0x00, 0x2f, ATA_UDMA6, VIA_BAD_AST },
  	{ "vt8237s",	PCI_DEVICE_ID_VIA_8237S,    0x00, 0x2f, ATA_UDMA6, VIA_BAD_AST },
  	{ "vt6410",	PCI_DEVICE_ID_VIA_6410,     0x00, 0x2f, ATA_UDMA6, VIA_BAD_AST },
  	{ "vt6415",	PCI_DEVICE_ID_VIA_6415,     0x00, 0xff, ATA_UDMA6, VIA_BAD_AST },
  	{ "vt8251",	PCI_DEVICE_ID_VIA_8251,     0x00, 0x2f, ATA_UDMA6, VIA_BAD_AST },
  	{ "vt8237",	PCI_DEVICE_ID_VIA_8237,     0x00, 0x2f, ATA_UDMA6, VIA_BAD_AST },
  	{ "vt8237a",	PCI_DEVICE_ID_VIA_8237A,    0x00, 0x2f, ATA_UDMA6, VIA_BAD_AST },
  	{ "vt8235",	PCI_DEVICE_ID_VIA_8235,     0x00, 0x2f, ATA_UDMA6, VIA_BAD_AST },
  	{ "vt8233a",	PCI_DEVICE_ID_VIA_8233A,    0x00, 0x2f, ATA_UDMA6, VIA_BAD_AST },
  	{ "vt8233c",	PCI_DEVICE_ID_VIA_8233C_0,  0x00, 0x2f, ATA_UDMA5, },
  	{ "vt8233",	PCI_DEVICE_ID_VIA_8233_0,   0x00, 0x2f, ATA_UDMA5, },
  	{ "vt8231",	PCI_DEVICE_ID_VIA_8231,     0x00, 0x2f, ATA_UDMA5, },
  	{ "vt82c686b",	PCI_DEVICE_ID_VIA_82C686,   0x40, 0x4f, ATA_UDMA5, },
  	{ "vt82c686a",	PCI_DEVICE_ID_VIA_82C686,   0x10, 0x2f, ATA_UDMA4, },
  	{ "vt82c686",	PCI_DEVICE_ID_VIA_82C686,   0x00, 0x0f, ATA_UDMA2, VIA_BAD_CLK66 },
  	{ "vt82c596b",	PCI_DEVICE_ID_VIA_82C596,   0x10, 0x2f, ATA_UDMA4, },
  	{ "vt82c596a",	PCI_DEVICE_ID_VIA_82C596,   0x00, 0x0f, ATA_UDMA2, VIA_BAD_CLK66 },
  	{ "vt82c586b",	PCI_DEVICE_ID_VIA_82C586_0, 0x47, 0x4f, ATA_UDMA2, VIA_SET_FIFO },
  	{ "vt82c586b",	PCI_DEVICE_ID_VIA_82C586_0, 0x40, 0x46, ATA_UDMA2, VIA_SET_FIFO | VIA_BAD_PREQ },
  	{ "vt82c586b",	PCI_DEVICE_ID_VIA_82C586_0, 0x30, 0x3f, ATA_UDMA2, VIA_SET_FIFO },
  	{ "vt82c586a",	PCI_DEVICE_ID_VIA_82C586_0, 0x20, 0x2f, ATA_UDMA2, VIA_SET_FIFO },
  	{ "vt82c586",	PCI_DEVICE_ID_VIA_82C586_0, 0x00, 0x0f,      0x00, VIA_SET_FIFO },
  	{ "vt82c576",	PCI_DEVICE_ID_VIA_82C576,   0x00, 0x2f,      0x00, VIA_SET_FIFO | VIA_NO_UNMASK },
  	{ "vt82c576",	PCI_DEVICE_ID_VIA_82C576,   0x00, 0x2f,      0x00, VIA_SET_FIFO | VIA_NO_UNMASK | VIA_BAD_ID },
  	{ "vtxxxx",	PCI_DEVICE_ID_VIA_ANON,     0x00, 0x2f, ATA_UDMA6, VIA_BAD_AST },
  	{ NULL }
  };
  
  static unsigned int via_clock;
  static char *via_dma[] = { "16", "25", "33", "44", "66", "100", "133" };
  
  struct via82cxxx_dev
  {
  	struct via_isa_bridge *via_config;
  	unsigned int via_80w;
  };
  
  /**
   *	via_set_speed			-	write timing registers
   *	@dev: PCI device
   *	@dn: device
   *	@timing: IDE timing data to use
   *
   *	via_set_speed writes timing values to the chipset registers
   */
  
  static void via_set_speed(ide_hwif_t *hwif, u8 dn, struct ide_timing *timing)
  {
  	struct pci_dev *dev = to_pci_dev(hwif->dev);
  	struct ide_host *host = pci_get_drvdata(dev);
  	struct via82cxxx_dev *vdev = host->host_priv;
  	u8 t;
  
  	if (~vdev->via_config->flags & VIA_BAD_AST) {
  		pci_read_config_byte(dev, VIA_ADDRESS_SETUP, &t);
  		t = (t & ~(3 << ((3 - dn) << 1))) | ((clamp_val(timing->setup, 1, 4) - 1) << ((3 - dn) << 1));
  		pci_write_config_byte(dev, VIA_ADDRESS_SETUP, t);
  	}
  
  	pci_write_config_byte(dev, VIA_8BIT_TIMING + (1 - (dn >> 1)),
  		((clamp_val(timing->act8b, 1, 16) - 1) << 4) | (clamp_val(timing->rec8b, 1, 16) - 1));
  
  	pci_write_config_byte(dev, VIA_DRIVE_TIMING + (3 - dn),
  		((clamp_val(timing->active, 1, 16) - 1) << 4) | (clamp_val(timing->recover, 1, 16) - 1));
  
  	switch (vdev->via_config->udma_mask) {
  	case ATA_UDMA2: t = timing->udma ? (0xe0 | (clamp_val(timing->udma, 2, 5) - 2)) : 0x03; break;
  	case ATA_UDMA4: t = timing->udma ? (0xe8 | (clamp_val(timing->udma, 2, 9) - 2)) : 0x0f; break;
  	case ATA_UDMA5: t = timing->udma ? (0xe0 | (clamp_val(timing->udma, 2, 9) - 2)) : 0x07; break;
  	case ATA_UDMA6: t = timing->udma ? (0xe0 | (clamp_val(timing->udma, 2, 9) - 2)) : 0x07; break;
  	}
  
  	/* Set UDMA unless device is not UDMA capable */
  	if (vdev->via_config->udma_mask) {
  		u8 udma_etc;
  
  		pci_read_config_byte(dev, VIA_UDMA_TIMING + 3 - dn, &udma_etc);
  
  		/* clear transfer mode bit */
  		udma_etc &= ~0x20;
  
  		if (timing->udma) {
  			/* preserve 80-wire cable detection bit */
  			udma_etc &= 0x10;
  			udma_etc |= t;
  		}
  
  		pci_write_config_byte(dev, VIA_UDMA_TIMING + 3 - dn, udma_etc);
  	}
  }
  
  /**
   *	via_set_drive		-	configure transfer mode
   *	@hwif: port
   *	@drive: Drive to set up
   *
   *	via_set_drive() computes timing values configures the chipset to
   *	a desired transfer mode.  It also can be called by upper layers.
   */
  
  static void via_set_drive(ide_hwif_t *hwif, ide_drive_t *drive)
  {
  	ide_drive_t *peer = ide_get_pair_dev(drive);
  	struct pci_dev *dev = to_pci_dev(hwif->dev);
  	struct ide_host *host = pci_get_drvdata(dev);
  	struct via82cxxx_dev *vdev = host->host_priv;
  	struct ide_timing t, p;
  	unsigned int T, UT;
  	const u8 speed = drive->dma_mode;
  
  	T = 1000000000 / via_clock;
  
  	switch (vdev->via_config->udma_mask) {
  	case ATA_UDMA2: UT = T;   break;
  	case ATA_UDMA4: UT = T/2; break;
  	case ATA_UDMA5: UT = T/3; break;
  	case ATA_UDMA6: UT = T/4; break;
  	default:	UT = T;
  	}
  
  	ide_timing_compute(drive, speed, &t, T, UT);
  
  	if (peer) {
  		ide_timing_compute(peer, peer->pio_mode, &p, T, UT);
  		ide_timing_merge(&p, &t, &t, IDE_TIMING_8BIT);
  	}
  
  	via_set_speed(hwif, drive->dn, &t);
  }
  
  /**
   *	via_set_pio_mode	-	set host controller for PIO mode
   *	@hwif: port
   *	@drive: drive
   *
   *	A callback from the upper layers for PIO-only tuning.
   */
  
  static void via_set_pio_mode(ide_hwif_t *hwif, ide_drive_t *drive)
  {
  	drive->dma_mode = drive->pio_mode;
  	via_set_drive(hwif, drive);
  }
  
  static struct via_isa_bridge *via_config_find(struct pci_dev **isa)
  {
  	struct via_isa_bridge *via_config;
  
  	for (via_config = via_isa_bridges;
  	     via_config->id != PCI_DEVICE_ID_VIA_ANON; via_config++)
  		if ((*isa = pci_get_device(PCI_VENDOR_ID_VIA +
  			!!(via_config->flags & VIA_BAD_ID),
  			via_config->id, NULL))) {
  
  			if ((*isa)->revision >= via_config->rev_min &&
  			    (*isa)->revision <= via_config->rev_max)
  				break;
  			pci_dev_put(*isa);
  		}
  
  	return via_config;
  }
  
  /*
   * Check and handle 80-wire cable presence
   */
  static void via_cable_detect(struct via82cxxx_dev *vdev, u32 u)
  {
  	int i;
  
  	switch (vdev->via_config->udma_mask) {
  		case ATA_UDMA4:
  			for (i = 24; i >= 0; i -= 8)
  				if (((u >> (i & 16)) & 8) &&
  				    ((u >> i) & 0x20) &&
  				     (((u >> i) & 7) < 2)) {
  					/*
  					 * 2x PCI clock and
  					 * UDMA w/ < 3T/cycle
  					 */
  					vdev->via_80w |= (1 << (1 - (i >> 4)));
  				}
  			break;
  
  		case ATA_UDMA5:
  			for (i = 24; i >= 0; i -= 8)
  				if (((u >> i) & 0x10) ||
  				    (((u >> i) & 0x20) &&
  				     (((u >> i) & 7) < 4))) {
  					/* BIOS 80-wire bit or
  					 * UDMA w/ < 60ns/cycle
  					 */
  					vdev->via_80w |= (1 << (1 - (i >> 4)));
  				}
  			break;
  
  		case ATA_UDMA6:
  			for (i = 24; i >= 0; i -= 8)
  				if (((u >> i) & 0x10) ||
  				    (((u >> i) & 0x20) &&
  				     (((u >> i) & 7) < 6))) {
  					/* BIOS 80-wire bit or
  					 * UDMA w/ < 60ns/cycle
  					 */
  					vdev->via_80w |= (1 << (1 - (i >> 4)));
  				}
  			break;
  	}
  }
  
  /**
   *	init_chipset_via82cxxx	-	initialization handler
   *	@dev: PCI device
   *
   *	The initialization callback. Here we determine the IDE chip type
   *	and initialize its drive independent registers.
   */
  
  static int init_chipset_via82cxxx(struct pci_dev *dev)
  {
  	struct ide_host *host = pci_get_drvdata(dev);
  	struct via82cxxx_dev *vdev = host->host_priv;
  	struct via_isa_bridge *via_config = vdev->via_config;
  	u8 t, v;
  	u32 u;
  
  	/*
  	 * Detect cable and configure Clk66
  	 */
  	pci_read_config_dword(dev, VIA_UDMA_TIMING, &u);
  
  	via_cable_detect(vdev, u);
  
  	if (via_config->udma_mask == ATA_UDMA4) {
  		/* Enable Clk66 */
  		pci_write_config_dword(dev, VIA_UDMA_TIMING, u|0x80008);
  	} else if (via_config->flags & VIA_BAD_CLK66) {
  		/* Would cause trouble on 596a and 686 */
  		pci_write_config_dword(dev, VIA_UDMA_TIMING, u & ~0x80008);
  	}
  
  	/*
  	 * Check whether interfaces are enabled.
  	 */
  
  	pci_read_config_byte(dev, VIA_IDE_ENABLE, &v);
  
  	/*
  	 * Set up FIFO sizes and thresholds.
  	 */
  
  	pci_read_config_byte(dev, VIA_FIFO_CONFIG, &t);
  
  	/* Disable PREQ# till DDACK# */
  	if (via_config->flags & VIA_BAD_PREQ) {
  		/* Would crash on 586b rev 41 */
  		t &= 0x7f;
  	}
  
  	/* Fix FIFO split between channels */
  	if (via_config->flags & VIA_SET_FIFO) {
  		t &= (t & 0x9f);
  		switch (v & 3) {
  			case 2: t |= 0x00; break;	/* 16 on primary */
  			case 1: t |= 0x60; break;	/* 16 on secondary */
  			case 3: t |= 0x20; break;	/* 8 pri 8 sec */
  		}
  	}
  
  	pci_write_config_byte(dev, VIA_FIFO_CONFIG, t);
  
  	return 0;
  }
  
  /*
   *	Cable special cases
   */
  
  static const struct dmi_system_id cable_dmi_table[] = {
  	{
  		.ident = "Acer Ferrari 3400",
  		.matches = {
  			DMI_MATCH(DMI_BOARD_VENDOR, "Acer,Inc."),
  			DMI_MATCH(DMI_BOARD_NAME, "Ferrari 3400"),
  		},
  	},
  	{ }
  };
  
  static int via_cable_override(struct pci_dev *pdev)
  {
  	/* Systems by DMI */
  	if (dmi_check_system(cable_dmi_table))
  		return 1;
  
  	/* Arima W730-K8/Targa Visionary 811/... */
  	if (pdev->subsystem_vendor == 0x161F &&
  	    pdev->subsystem_device == 0x2032)
  		return 1;
  
  	return 0;
  }
  
  static u8 via82cxxx_cable_detect(ide_hwif_t *hwif)
  {
  	struct pci_dev *pdev = to_pci_dev(hwif->dev);
  	struct ide_host *host = pci_get_drvdata(pdev);
  	struct via82cxxx_dev *vdev = host->host_priv;
  
  	if (via_cable_override(pdev))
  		return ATA_CBL_PATA40_SHORT;
  
  	if ((vdev->via_config->flags & VIA_SATA_PATA) && hwif->channel == 0)
  		return ATA_CBL_SATA;
  
  	if ((vdev->via_80w >> hwif->channel) & 1)
  		return ATA_CBL_PATA80;
  	else
  		return ATA_CBL_PATA40;
  }
  
  static const struct ide_port_ops via_port_ops = {
  	.set_pio_mode		= via_set_pio_mode,
  	.set_dma_mode		= via_set_drive,
  	.cable_detect		= via82cxxx_cable_detect,
  };
  
  static const struct ide_port_info via82cxxx_chipset = {
  	.name		= DRV_NAME,
  	.init_chipset	= init_chipset_via82cxxx,
  	.enablebits	= { { 0x40, 0x02, 0x02 }, { 0x40, 0x01, 0x01 } },
  	.port_ops	= &via_port_ops,
  	.host_flags	= IDE_HFLAG_PIO_NO_BLACKLIST |
  			  IDE_HFLAG_POST_SET_MODE |
  			  IDE_HFLAG_IO_32BIT,
  	.pio_mask	= ATA_PIO5,
  	.swdma_mask	= ATA_SWDMA2,
  	.mwdma_mask	= ATA_MWDMA2,
  };
  
  static int via_init_one(struct pci_dev *dev, const struct pci_device_id *id)
  {
  	struct pci_dev *isa = NULL;
  	struct via_isa_bridge *via_config;
  	struct via82cxxx_dev *vdev;
  	int rc;
  	u8 idx = id->driver_data;
  	struct ide_port_info d;
  
  	d = via82cxxx_chipset;
  
  	/*
  	 * Find the ISA bridge and check we know what it is.
  	 */
  	via_config = via_config_find(&isa);
  
  	/*
  	 * Print the boot message.
  	 */
  	printk(KERN_INFO DRV_NAME " %s: VIA %s (rev %02x) IDE %sDMA%s
  ",
  		pci_name(dev), via_config->name, isa->revision,
  		via_config->udma_mask ? "U" : "MW",
  		via_dma[via_config->udma_mask ?
  			(fls(via_config->udma_mask) - 1) : 0]);
  
  	pci_dev_put(isa);
  
  	/*
  	 * Determine system bus clock.
  	 */
  	via_clock = (ide_pci_clk ? ide_pci_clk : 33) * 1000;
  
  	switch (via_clock) {
  	case 33000: via_clock = 33333; break;
  	case 37000: via_clock = 37500; break;
  	case 41000: via_clock = 41666; break;
  	}
  
  	if (via_clock < 20000 || via_clock > 50000) {
  		printk(KERN_WARNING DRV_NAME ": User given PCI clock speed "
  			"impossible (%d), using 33 MHz instead.
  ", via_clock);
  		via_clock = 33333;
  	}
  
  	if (idx == 1)
  		d.enablebits[1].reg = d.enablebits[0].reg = 0;
  	else
  		d.host_flags |= IDE_HFLAG_NO_AUTODMA;
  
  	if (idx == VIA_IDFLAG_SINGLE)
  		d.host_flags |= IDE_HFLAG_SINGLE;
  
  	if ((via_config->flags & VIA_NO_UNMASK) == 0)
  		d.host_flags |= IDE_HFLAG_UNMASK_IRQS;
  
  	d.udma_mask = via_config->udma_mask;
  
  	vdev = kzalloc(sizeof(*vdev), GFP_KERNEL);
  	if (!vdev) {
  		printk(KERN_ERR DRV_NAME " %s: out of memory :(
  ",
  			pci_name(dev));
  		return -ENOMEM;
  	}
  
  	vdev->via_config = via_config;
  
  	rc = ide_pci_init_one(dev, &d, vdev);
  	if (rc)
  		kfree(vdev);
  
  	return rc;
  }
  
  static void via_remove(struct pci_dev *dev)
  {
  	struct ide_host *host = pci_get_drvdata(dev);
  	struct via82cxxx_dev *vdev = host->host_priv;
  
  	ide_pci_remove(dev);
  	kfree(vdev);
  }
  
  static const struct pci_device_id via_pci_tbl[] = {
  	{ PCI_VDEVICE(VIA, PCI_DEVICE_ID_VIA_82C576_1),  0 },
  	{ PCI_VDEVICE(VIA, PCI_DEVICE_ID_VIA_82C586_1),  0 },
  	{ PCI_VDEVICE(VIA, PCI_DEVICE_ID_VIA_CX700_IDE), 0 },
  	{ PCI_VDEVICE(VIA, PCI_DEVICE_ID_VIA_VX855_IDE), VIA_IDFLAG_SINGLE },
  	{ PCI_VDEVICE(VIA, PCI_DEVICE_ID_VIA_6410),      1 },
  	{ PCI_VDEVICE(VIA, PCI_DEVICE_ID_VIA_6415),      1 },
  	{ PCI_VDEVICE(VIA, PCI_DEVICE_ID_VIA_SATA_EIDE), 1 },
  	{ 0, },
  };
  MODULE_DEVICE_TABLE(pci, via_pci_tbl);
  
  static struct pci_driver via_pci_driver = {
  	.name 		= "VIA_IDE",
  	.id_table 	= via_pci_tbl,
  	.probe 		= via_init_one,
  	.remove		= via_remove,
  	.suspend	= ide_pci_suspend,
  	.resume		= ide_pci_resume,
  };
  
  static int __init via_ide_init(void)
  {
  	return ide_pci_register_driver(&via_pci_driver);
  }
  
  static void __exit via_ide_exit(void)
  {
  	pci_unregister_driver(&via_pci_driver);
  }
  
  module_init(via_ide_init);
  module_exit(via_ide_exit);
  
  MODULE_AUTHOR("Vojtech Pavlik, Bartlomiej Zolnierkiewicz, Michel Aubry, Jeff Garzik, Andre Hedrick");
  MODULE_DESCRIPTION("PCI driver module for VIA IDE");
  MODULE_LICENSE("GPL");