/*
   * pata_cmd64x.c 	- CMD64x PATA for new ATA layer
   *			  (C) 2005 Red Hat Inc
   *			  Alan Cox <alan@lxorguk.ukuu.org.uk>
   *			  (C) 2009-2010 Bartlomiej Zolnierkiewicz
   *			  (C) 2012 MontaVista Software, LLC <source@mvista.com>
   *
   * Based upon
   * linux/drivers/ide/pci/cmd64x.c		Version 1.30	Sept 10, 2002
   *
   * cmd64x.c: Enable interrupts at initialization time on Ultra/PCI machines.
   *           Note, this driver is not used at all on other systems because
   *           there the "BIOS" has done all of the following already.
   *           Due to massive hardware bugs, UltraDMA is only supported
   *           on the 646U2 and not on the 646U.
   *
   * Copyright (C) 1998		Eddie C. Dost  (ecd@skynet.be)
   * Copyright (C) 1998		David S. Miller (davem@redhat.com)
   *
   * Copyright (C) 1999-2002	Andre Hedrick <andre@linux-ide.org>
   *
   * TODO
   *	Testing work
   */
  
  #include <linux/kernel.h>
  #include <linux/module.h>
  #include <linux/pci.h>
  #include <linux/blkdev.h>
  #include <linux/delay.h>
  #include <scsi/scsi_host.h>
  #include <linux/libata.h>
  
  #define DRV_NAME "pata_cmd64x"
  #define DRV_VERSION "0.2.18"
  
  /*
   * CMD64x specific registers definition.
   */
  
  enum {
  	CFR 		= 0x50,
  		CFR_INTR_CH0  = 0x04,
  	CNTRL		= 0x51,
  		CNTRL_CH0     = 0x04,
  		CNTRL_CH1     = 0x08,
  	CMDTIM 		= 0x52,
  	ARTTIM0 	= 0x53,
  	DRWTIM0 	= 0x54,
  	ARTTIM1 	= 0x55,
  	DRWTIM1 	= 0x56,
  	ARTTIM23 	= 0x57,
  		ARTTIM23_DIS_RA2  = 0x04,
  		ARTTIM23_DIS_RA3  = 0x08,
  		ARTTIM23_INTR_CH1 = 0x10,
  	DRWTIM2 	= 0x58,
  	BRST 		= 0x59,
  	DRWTIM3 	= 0x5b,
  	BMIDECR0	= 0x70,
  	MRDMODE		= 0x71,
  		MRDMODE_INTR_CH0 = 0x04,
  		MRDMODE_INTR_CH1 = 0x08,
  	BMIDESR0	= 0x72,
  	UDIDETCR0	= 0x73,
  	DTPR0		= 0x74,
  	BMIDECR1	= 0x78,
  	BMIDECSR	= 0x79,
  	UDIDETCR1	= 0x7B,
  	DTPR1		= 0x7C
  };
  
  static int cmd648_cable_detect(struct ata_port *ap)
  {
  	struct pci_dev *pdev = to_pci_dev(ap->host->dev);
  	u8 r;
  
  	/* Check cable detect bits */
  	pci_read_config_byte(pdev, BMIDECSR, &r);
  	if (r & (1 << ap->port_no))
  		return ATA_CBL_PATA80;
  	return ATA_CBL_PATA40;
  }
  
  /**
   *	cmd64x_set_timing	-	set PIO and MWDMA timing
   *	@ap: ATA interface
   *	@adev: ATA device
   *	@mode: mode
   *
   *	Called to do the PIO and MWDMA mode setup.
   */
  
  static void cmd64x_set_timing(struct ata_port *ap, struct ata_device *adev, u8 mode)
  {
  	struct pci_dev *pdev = to_pci_dev(ap->host->dev);
  	struct ata_timing t;
  	const unsigned long T = 1000000 / 33;
  	const u8 setup_data[] = { 0x40, 0x40, 0x40, 0x80, 0x00 };
  
  	u8 reg;
  
  	/* Port layout is not logical so use a table */
  	const u8 arttim_port[2][2] = {
  		{ ARTTIM0, ARTTIM1 },
  		{ ARTTIM23, ARTTIM23 }
  	};
  	const u8 drwtim_port[2][2] = {
  		{ DRWTIM0, DRWTIM1 },
  		{ DRWTIM2, DRWTIM3 }
  	};
  
  	int arttim = arttim_port[ap->port_no][adev->devno];
  	int drwtim = drwtim_port[ap->port_no][adev->devno];
  
  	/* ata_timing_compute is smart and will produce timings for MWDMA
  	   that don't violate the drives PIO capabilities. */
  	if (ata_timing_compute(adev, mode, &t, T, 0) < 0) {
  		printk(KERN_ERR DRV_NAME ": mode computation failed.
  ");
  		return;
  	}
  	if (ap->port_no) {
  		/* Slave has shared address setup */
  		struct ata_device *pair = ata_dev_pair(adev);
  
  		if (pair) {
  			struct ata_timing tp;
  			ata_timing_compute(pair, pair->pio_mode, &tp, T, 0);
  			ata_timing_merge(&t, &tp, &t, ATA_TIMING_SETUP);
  		}
  	}
  
  	printk(KERN_DEBUG DRV_NAME ": active %d recovery %d setup %d.
  ",
  		t.active, t.recover, t.setup);
  	if (t.recover > 16) {
  		t.active += t.recover - 16;
  		t.recover = 16;
  	}
  	if (t.active > 16)
  		t.active = 16;
  
  	/* Now convert the clocks into values we can actually stuff into
  	   the chip */
  
  	if (t.recover == 16)
  		t.recover = 0;
  	else if (t.recover > 1)
  		t.recover--;
  	else
  		t.recover = 15;
  
  	if (t.setup > 4)
  		t.setup = 0xC0;
  	else
  		t.setup = setup_data[t.setup];
  
  	t.active &= 0x0F;	/* 0 = 16 */
  
  	/* Load setup timing */
  	pci_read_config_byte(pdev, arttim, &reg);
  	reg &= 0x3F;
  	reg |= t.setup;
  	pci_write_config_byte(pdev, arttim, reg);
  
  	/* Load active/recovery */
  	pci_write_config_byte(pdev, drwtim, (t.active << 4) | t.recover);
  }
  
  /**
   *	cmd64x_set_piomode	-	set initial PIO mode data
   *	@ap: ATA interface
   *	@adev: ATA device
   *
   *	Used when configuring the devices ot set the PIO timings. All the
   *	actual work is done by the PIO/MWDMA setting helper
   */
  
  static void cmd64x_set_piomode(struct ata_port *ap, struct ata_device *adev)
  {
  	cmd64x_set_timing(ap, adev, adev->pio_mode);
  }
  
  /**
   *	cmd64x_set_dmamode	-	set initial DMA mode data
   *	@ap: ATA interface
   *	@adev: ATA device
   *
   *	Called to do the DMA mode setup.
   */
  
  static void cmd64x_set_dmamode(struct ata_port *ap, struct ata_device *adev)
  {
  	static const u8 udma_data[] = {
  		0x30, 0x20, 0x10, 0x20, 0x10, 0x00
  	};
  
  	struct pci_dev *pdev = to_pci_dev(ap->host->dev);
  	u8 regU, regD;
  
  	int pciU = UDIDETCR0 + 8 * ap->port_no;
  	int pciD = BMIDESR0 + 8 * ap->port_no;
  	int shift = 2 * adev->devno;
  
  	pci_read_config_byte(pdev, pciD, &regD);
  	pci_read_config_byte(pdev, pciU, &regU);
  
  	/* DMA bits off */
  	regD &= ~(0x20 << adev->devno);
  	/* DMA control bits */
  	regU &= ~(0x30 << shift);
  	/* DMA timing bits */
  	regU &= ~(0x05 << adev->devno);
  
  	if (adev->dma_mode >= XFER_UDMA_0) {
  		/* Merge the timing value */
  		regU |= udma_data[adev->dma_mode - XFER_UDMA_0] << shift;
  		/* Merge the control bits */
  		regU |= 1 << adev->devno; /* UDMA on */
  		if (adev->dma_mode > XFER_UDMA_2) /* 15nS timing */
  			regU |= 4 << adev->devno;
  	} else {
  		regU &= ~ (1 << adev->devno);	/* UDMA off */
  		cmd64x_set_timing(ap, adev, adev->dma_mode);
  	}
  
  	regD |= 0x20 << adev->devno;
  
  	pci_write_config_byte(pdev, pciU, regU);
  	pci_write_config_byte(pdev, pciD, regD);
  }
  
  /**
   *	cmd64x_sff_irq_check	-	check IDE interrupt
   *	@ap: ATA interface
   *
   *	Check IDE interrupt in CFR/ARTTIM23 registers.
   */
  
  static bool cmd64x_sff_irq_check(struct ata_port *ap)
  {
  	struct pci_dev *pdev = to_pci_dev(ap->host->dev);
  	int irq_mask = ap->port_no ? ARTTIM23_INTR_CH1 : CFR_INTR_CH0;
  	int irq_reg  = ap->port_no ? ARTTIM23 : CFR;
  	u8 irq_stat;
  
  	/* NOTE: reading the register should clear the interrupt */
  	pci_read_config_byte(pdev, irq_reg, &irq_stat);
  
  	return irq_stat & irq_mask;
  }
  
  /**
   *	cmd64x_sff_irq_clear	-	clear IDE interrupt
   *	@ap: ATA interface
   *
   *	Clear IDE interrupt in CFR/ARTTIM23 and DMA status registers.
   */
  
  static void cmd64x_sff_irq_clear(struct ata_port *ap)
  {
  	struct pci_dev *pdev = to_pci_dev(ap->host->dev);
  	int irq_reg = ap->port_no ? ARTTIM23 : CFR;
  	u8 irq_stat;
  
  	ata_bmdma_irq_clear(ap);
  
  	/* Reading the register should be enough to clear the interrupt */
  	pci_read_config_byte(pdev, irq_reg, &irq_stat);
  }
  
  /**
   *	cmd648_sff_irq_check	-	check IDE interrupt
   *	@ap: ATA interface
   *
   *	Check IDE interrupt in MRDMODE register.
   */
  
  static bool cmd648_sff_irq_check(struct ata_port *ap)
  {
  	struct pci_dev *pdev = to_pci_dev(ap->host->dev);
  	unsigned long base = pci_resource_start(pdev, 4);
  	int irq_mask = ap->port_no ? MRDMODE_INTR_CH1 : MRDMODE_INTR_CH0;
  	u8 mrdmode = inb(base + 1);
  
  	return mrdmode & irq_mask;
  }
  
  /**
   *	cmd648_sff_irq_clear	-	clear IDE interrupt
   *	@ap: ATA interface
   *
   *	Clear IDE interrupt in MRDMODE and DMA status registers.
   */
  
  static void cmd648_sff_irq_clear(struct ata_port *ap)
  {
  	struct pci_dev *pdev = to_pci_dev(ap->host->dev);
  	unsigned long base = pci_resource_start(pdev, 4);
  	int irq_mask = ap->port_no ? MRDMODE_INTR_CH1 : MRDMODE_INTR_CH0;
  	u8 mrdmode;
  
  	ata_bmdma_irq_clear(ap);
  
  	/* Clear this port's interrupt bit (leaving the other port alone) */
  	mrdmode  = inb(base + 1);
  	mrdmode &= ~(MRDMODE_INTR_CH0 | MRDMODE_INTR_CH1);
  	outb(mrdmode | irq_mask, base + 1);
  }
  
  /**
   *	cmd646r1_bmdma_stop	-	DMA stop callback
   *	@qc: Command in progress
   *
   *	Stub for now while investigating the r1 quirk in the old driver.
   */
  
  static void cmd646r1_bmdma_stop(struct ata_queued_cmd *qc)
  {
  	ata_bmdma_stop(qc);
  }
  
  static struct scsi_host_template cmd64x_sht = {
  	ATA_BMDMA_SHT(DRV_NAME),
  };
  
  static const struct ata_port_operations cmd64x_base_ops = {
  	.inherits	= &ata_bmdma_port_ops,
  	.set_piomode	= cmd64x_set_piomode,
  	.set_dmamode	= cmd64x_set_dmamode,
  };
  
  static struct ata_port_operations cmd64x_port_ops = {
  	.inherits	= &cmd64x_base_ops,
  	.sff_irq_check	= cmd64x_sff_irq_check,
  	.sff_irq_clear	= cmd64x_sff_irq_clear,
  	.cable_detect	= ata_cable_40wire,
  };
  
  static struct ata_port_operations cmd646r1_port_ops = {
  	.inherits	= &cmd64x_base_ops,
  	.sff_irq_check	= cmd64x_sff_irq_check,
  	.sff_irq_clear	= cmd64x_sff_irq_clear,
  	.bmdma_stop	= cmd646r1_bmdma_stop,
  	.cable_detect	= ata_cable_40wire,
  };
  
  static struct ata_port_operations cmd646r3_port_ops = {
  	.inherits	= &cmd64x_base_ops,
  	.sff_irq_check	= cmd648_sff_irq_check,
  	.sff_irq_clear	= cmd648_sff_irq_clear,
  	.cable_detect	= ata_cable_40wire,
  };
  
  static struct ata_port_operations cmd648_port_ops = {
  	.inherits	= &cmd64x_base_ops,
  	.sff_irq_check	= cmd648_sff_irq_check,
  	.sff_irq_clear	= cmd648_sff_irq_clear,
  	.cable_detect	= cmd648_cable_detect,
  };
  
  static void cmd64x_fixup(struct pci_dev *pdev)
  {
  	u8 mrdmode;
  
  	pci_write_config_byte(pdev, PCI_LATENCY_TIMER, 64);
  	pci_read_config_byte(pdev, MRDMODE, &mrdmode);
  	mrdmode &= ~0x30;	/* IRQ set up */
  	mrdmode |= 0x02;	/* Memory read line enable */
  	pci_write_config_byte(pdev, MRDMODE, mrdmode);
  
  	/* PPC specific fixup copied from old driver */
  #ifdef CONFIG_PPC
  	pci_write_config_byte(pdev, UDIDETCR0, 0xF0);
  #endif
  }
  
  static int cmd64x_init_one(struct pci_dev *pdev, const struct pci_device_id *id)
  {
  	static const struct ata_port_info cmd_info[7] = {
  		{	/* CMD 643 - no UDMA */
  			.flags = ATA_FLAG_SLAVE_POSS,
  			.pio_mask = ATA_PIO4,
  			.mwdma_mask = ATA_MWDMA2,
  			.port_ops = &cmd64x_port_ops
  		},
  		{	/* CMD 646 with broken UDMA */
  			.flags = ATA_FLAG_SLAVE_POSS,
  			.pio_mask = ATA_PIO4,
  			.mwdma_mask = ATA_MWDMA2,
  			.port_ops = &cmd64x_port_ops
  		},
  		{	/* CMD 646U with broken UDMA */
  			.flags = ATA_FLAG_SLAVE_POSS,
  			.pio_mask = ATA_PIO4,
  			.mwdma_mask = ATA_MWDMA2,
  			.port_ops = &cmd646r3_port_ops
  		},
  		{	/* CMD 646U2 with working UDMA */
  			.flags = ATA_FLAG_SLAVE_POSS,
  			.pio_mask = ATA_PIO4,
  			.mwdma_mask = ATA_MWDMA2,
  			.udma_mask = ATA_UDMA2,
  			.port_ops = &cmd646r3_port_ops
  		},
  		{	/* CMD 646 rev 1  */
  			.flags = ATA_FLAG_SLAVE_POSS,
  			.pio_mask = ATA_PIO4,
  			.mwdma_mask = ATA_MWDMA2,
  			.port_ops = &cmd646r1_port_ops
  		},
  		{	/* CMD 648 */
  			.flags = ATA_FLAG_SLAVE_POSS,
  			.pio_mask = ATA_PIO4,
  			.mwdma_mask = ATA_MWDMA2,
  			.udma_mask = ATA_UDMA4,
  			.port_ops = &cmd648_port_ops
  		},
  		{	/* CMD 649 */
  			.flags = ATA_FLAG_SLAVE_POSS,
  			.pio_mask = ATA_PIO4,
  			.mwdma_mask = ATA_MWDMA2,
  			.udma_mask = ATA_UDMA5,
  			.port_ops = &cmd648_port_ops
  		}
  	};
  	const struct ata_port_info *ppi[] = {
  		&cmd_info[id->driver_data],
  		&cmd_info[id->driver_data],
  		NULL
  	};
  	u8 reg;
  	int rc;
  	struct pci_dev *bridge = pdev->bus->self;
  	/* mobility split bridges don't report enabled ports correctly */
  	int port_ok = !(bridge && bridge->vendor ==
  			PCI_VENDOR_ID_MOBILITY_ELECTRONICS);
  	/* all (with exceptions below) apart from 643 have CNTRL_CH0 bit */
  	int cntrl_ch0_ok = (id->driver_data != 0);
  
  	rc = pcim_enable_device(pdev);
  	if (rc)
  		return rc;
  
  	if (id->driver_data == 0)	/* 643 */
  		ata_pci_bmdma_clear_simplex(pdev);
  
  	if (pdev->device == PCI_DEVICE_ID_CMD_646)
  		switch (pdev->revision) {
  		/* UDMA works since rev 5 */
  		default:
  			ppi[0] = &cmd_info[3];
  			ppi[1] = &cmd_info[3];
  			break;
  		/* Interrupts in MRDMODE since rev 3 */
  		case 3:
  		case 4:
  			ppi[0] = &cmd_info[2];
  			ppi[1] = &cmd_info[2];
  			break;
  		/* Rev 1 with other problems? */
  		case 1:
  			ppi[0] = &cmd_info[4];
  			ppi[1] = &cmd_info[4];
  			/* FALL THRU */
  		/* Early revs have no CNTRL_CH0 */
  		case 2:
  		case 0:
  			cntrl_ch0_ok = 0;
  			break;
  		}
  
  	cmd64x_fixup(pdev);
  
  	/* check for enabled ports */
  	pci_read_config_byte(pdev, CNTRL, &reg);
  	if (!port_ok)
  		dev_notice(&pdev->dev, "Mobility Bridge detected, ignoring CNTRL port enable/disable
  ");
  	if (port_ok && cntrl_ch0_ok && !(reg & CNTRL_CH0)) {
  		dev_notice(&pdev->dev, "Primary port is disabled
  ");
  		ppi[0] = &ata_dummy_port_info;
  
  	}
  	if (port_ok && !(reg & CNTRL_CH1)) {
  		dev_notice(&pdev->dev, "Secondary port is disabled
  ");
  		ppi[1] = &ata_dummy_port_info;
  	}
  
  	return ata_pci_bmdma_init_one(pdev, ppi, &cmd64x_sht, NULL, 0);
  }
  
  #ifdef CONFIG_PM_SLEEP
  static int cmd64x_reinit_one(struct pci_dev *pdev)
  {
  	struct ata_host *host = pci_get_drvdata(pdev);
  	int rc;
  
  	rc = ata_pci_device_do_resume(pdev);
  	if (rc)
  		return rc;
  
  	cmd64x_fixup(pdev);
  
  	ata_host_resume(host);
  	return 0;
  }
  #endif
  
  static const struct pci_device_id cmd64x[] = {
  	{ PCI_VDEVICE(CMD, PCI_DEVICE_ID_CMD_643), 0 },
  	{ PCI_VDEVICE(CMD, PCI_DEVICE_ID_CMD_646), 1 },
  	{ PCI_VDEVICE(CMD, PCI_DEVICE_ID_CMD_648), 5 },
  	{ PCI_VDEVICE(CMD, PCI_DEVICE_ID_CMD_649), 6 },
  
  	{ },
  };
  
  static struct pci_driver cmd64x_pci_driver = {
  	.name 		= DRV_NAME,
  	.id_table	= cmd64x,
  	.probe 		= cmd64x_init_one,
  	.remove		= ata_pci_remove_one,
  #ifdef CONFIG_PM_SLEEP
  	.suspend	= ata_pci_device_suspend,
  	.resume		= cmd64x_reinit_one,
  #endif
  };
  
  module_pci_driver(cmd64x_pci_driver);
  
  MODULE_AUTHOR("Alan Cox");
  MODULE_DESCRIPTION("low-level driver for CMD64x series PATA controllers");
  MODULE_LICENSE("GPL");
  MODULE_DEVICE_TABLE(pci, cmd64x);
  MODULE_VERSION(DRV_VERSION);