/*
 *    pata_oldpiix.c - Intel PATA/SATA controllers
 *
 *	(C) 2005 Red Hat <alan@redhat.com>
 *
 *    Some parts based on ata_piix.c by Jeff Garzik and others.
 *
 *    Early PIIX differs significantly from the later PIIX as it lacks
 *    SITRE and the slave timing registers. This means that you have to
 *    set timing per channel, or be clever. Libata tells us whenever it
 *    does drive selection and we use this to reload the timings.
 *
 *    Because of these behaviour differences PIIX gets its own driver module.
 */

#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/device.h>
#include <scsi/scsi_host.h>
#include <linux/libata.h>
#include <linux/ata.h>

#define DRV_NAME	"pata_oldpiix"
#define DRV_VERSION	"0.5.1"

/**
 *	oldpiix_pre_reset		-	probe begin
 *	@ap: ATA port
 *
 *	Set up cable type and use generic probe init
 */

static int oldpiix_pre_reset(struct ata_port *ap)
{
	struct pci_dev *pdev = to_pci_dev(ap->host->dev);
	static const struct pci_bits oldpiix_enable_bits[] = {
		{ 0x41U, 1U, 0x80UL, 0x80UL },	/* port 0 */
		{ 0x43U, 1U, 0x80UL, 0x80UL },	/* port 1 */
	};

	if (!pci_test_config_bits(pdev, &oldpiix_enable_bits[ap->port_no])) {
		ata_port_disable(ap);
		printk(KERN_INFO "ata%u: port disabled. ignoring.\n", ap->id);
		return 0;
	}
	ap->cbl = ATA_CBL_PATA40;
	return ata_std_prereset(ap);
}

/**
 *	oldpiix_pata_error_handler - Probe specified port on PATA host controller
 *	@ap: Port to probe
 *	@classes:
 *
 *	LOCKING:
 *	None (inherited from caller).
 */

static void oldpiix_pata_error_handler(struct ata_port *ap)
{
	ata_bmdma_drive_eh(ap, oldpiix_pre_reset, ata_std_softreset, NULL, ata_std_postreset);
}

/**
 *	oldpiix_set_piomode - Initialize host controller PATA PIO timings
 *	@ap: Port whose timings we are configuring
 *	@adev: um
 *
 *	Set PIO mode for device, in host controller PCI config space.
 *
 *	LOCKING:
 *	None (inherited from caller).
 */

static void oldpiix_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 idetm_port= ap->port_no ? 0x42 : 0x40;
	u16 idetm_data;
	int control = 0;

	/*
	 *	See Intel Document 298600-004 for the timing programing rules
	 *	for PIIX/ICH. Note that the early PIIX does not have the slave
	 *	timing port at 0x44.
	 */

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

	if (pio > 2)
		control |= 1;	/* TIME1 enable */
	if (ata_pio_need_iordy(adev))
		control |= 2;	/* IE IORDY */

	/* Intel specifies that the PPE functionality is for disk only */
	if (adev->class == ATA_DEV_ATA)
		control |= 4;	/* PPE enable */

	pci_read_config_word(dev, idetm_port, &idetm_data);

	/* Enable PPE, IE and TIME as appropriate. Clear the other
	   drive timing bits */
	if (adev->devno == 0) {
		idetm_data &= 0xCCE0;
		idetm_data |= control;
	} else {
		idetm_data &= 0xCC0E;
		idetm_data |= (control << 4);
	}
	idetm_data |= (timings[pio][0] << 12) |
			(timings[pio][1] << 8);
	pci_write_config_word(dev, idetm_port, idetm_data);

	/* Track which port is configured */
	ap->private_data = adev;
}

/**
 *	oldpiix_set_dmamode - Initialize host controller PATA DMA timings
 *	@ap: Port whose timings we are configuring
 *	@adev: Device to program
 *	@isich: True if the device is an ICH and has IOCFG registers
 *
 *	Set MWDMA mode for device, in host controller PCI config space.
 *
 *	LOCKING:
 *	None (inherited from caller).
 */

static void oldpiix_set_dmamode (struct ata_port *ap, struct ata_device *adev)
{
	struct pci_dev *dev	= to_pci_dev(ap->host->dev);
	u8 idetm_port		= ap->port_no ? 0x42 : 0x40;
	u16 idetm_data;

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

	/*
	 * 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;
	const unsigned int needed_pio[3] = {
		XFER_PIO_0, XFER_PIO_3, XFER_PIO_4
	};
	int pio = needed_pio[mwdma] - XFER_PIO_0;

	pci_read_config_word(dev, idetm_port, &idetm_data);

	control = 3;	/* IORDY|TIME0 */
	/* Intel specifies that the PPE functionality is for disk only */
	if (adev->class == ATA_DEV_ATA)
		control |= 4;	/* PPE enable */

	/* 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 */

	/* Mask out the relevant control and timing bits we will load. Also
	   clear the other drive TIME register as a precaution */
	if (adev->devno == 0) {
		idetm_data &= 0xCCE0;
		idetm_data |= control;
	} else {
		idetm_data &= 0xCC0E;
		idetm_data |= (control << 4);
	}
	idetm_data |= (timings[pio][0] << 12) | (timings[pio][1] << 8);
	pci_write_config_word(dev, idetm_port, idetm_data);

	/* Track which port is configured */
	ap->private_data = adev;
}

/**
 *	oldpiix_qc_issue_prot	-	command issue
 *	@qc: command pending
 *
 *	Called when the libata layer is about to issue a command. We wrap
 *	this interface so that we can load the correct ATA timings if
 *	neccessary. Our logic also clears TIME0/TIME1 for the other device so
 *	that, even if we get this wrong, cycles to the other device will
 *	be made PIO0.
 */

static unsigned int oldpiix_qc_issue_prot(struct ata_queued_cmd *qc)
{
	struct ata_port *ap = qc->ap;
	struct ata_device *adev = qc->dev;

	if (adev != ap->private_data) {
		if (adev->dma_mode)
			oldpiix_set_dmamode(ap, adev);
		else if (adev->pio_mode)
			oldpiix_set_piomode(ap, adev);
	}
	return ata_qc_issue_prot(qc);
}


static struct scsi_host_template oldpiix_sht = {
	.module			= THIS_MODULE,
	.name			= DRV_NAME,
	.ioctl			= ata_scsi_ioctl,
	.queuecommand		= ata_scsi_queuecmd,
	.can_queue		= ATA_DEF_QUEUE,
	.this_id		= ATA_SHT_THIS_ID,
	.sg_tablesize		= LIBATA_MAX_PRD,
	.max_sectors		= ATA_MAX_SECTORS,
	.cmd_per_lun		= ATA_SHT_CMD_PER_LUN,
	.emulated		= ATA_SHT_EMULATED,
	.use_clustering		= ATA_SHT_USE_CLUSTERING,
	.proc_name		= DRV_NAME,
	.dma_boundary		= ATA_DMA_BOUNDARY,
	.slave_configure	= ata_scsi_slave_config,
	.bios_param		= ata_std_bios_param,
};

static const struct ata_port_operations oldpiix_pata_ops = {
	.port_disable		= ata_port_disable,
	.set_piomode		= oldpiix_set_piomode,
	.set_dmamode		= oldpiix_set_dmamode,
	.mode_filter		= ata_pci_default_filter,

	.tf_load		= ata_tf_load,
	.tf_read		= ata_tf_read,
	.check_status		= ata_check_status,
	.exec_command		= ata_exec_command,
	.dev_select		= ata_std_dev_select,

	.freeze			= ata_bmdma_freeze,
	.thaw			= ata_bmdma_thaw,
	.error_handler		= oldpiix_pata_error_handler,
	.post_internal_cmd 	= ata_bmdma_post_internal_cmd,

	.bmdma_setup		= ata_bmdma_setup,
	.bmdma_start		= ata_bmdma_start,
	.bmdma_stop		= ata_bmdma_stop,
	.bmdma_status		= ata_bmdma_status,
	.qc_prep		= ata_qc_prep,
	.qc_issue		= oldpiix_qc_issue_prot,
	.data_xfer		= ata_pio_data_xfer,

	.irq_handler		= ata_interrupt,
	.irq_clear		= ata_bmdma_irq_clear,

	.port_start		= ata_port_start,
	.port_stop		= ata_port_stop,
	.host_stop		= ata_host_stop,
};


/**
 *	oldpiix_init_one - Register PIIX ATA PCI device with kernel services
 *	@pdev: PCI device to register
 *	@ent: Entry in oldpiix_pci_tbl matching with @pdev
 *
 *	Called from kernel PCI layer.  We probe for combined mode (sigh),
 *	and then hand over control to libata, for it to do the rest.
 *
 *	LOCKING:
 *	Inherited from PCI layer (may sleep).
 *
 *	RETURNS:
 *	Zero on success, or -ERRNO value.
 */

static int oldpiix_init_one (struct pci_dev *pdev, const struct pci_device_id *ent)
{
	static int printed_version;
	static struct ata_port_info info = {
		.sht		= &oldpiix_sht,
		.flags		= ATA_FLAG_SLAVE_POSS | ATA_FLAG_SRST,
		.pio_mask	= 0x1f,	/* pio0-4 */
		.mwdma_mask	= 0x07, /* mwdma1-2 */
		.port_ops	= &oldpiix_pata_ops,
	};
	static struct ata_port_info *port_info[2] = { &info, &info };

	if (!printed_version++)
		dev_printk(KERN_DEBUG, &pdev->dev,
			   "version " DRV_VERSION "\n");

	return ata_pci_init_one(pdev, port_info, 2);
}

static const struct pci_device_id oldpiix_pci_tbl[] = {
	{ PCI_DEVICE(0x8086, 0x1230), },
	{ }	/* terminate list */
};

static struct pci_driver oldpiix_pci_driver = {
	.name			= DRV_NAME,
	.id_table		= oldpiix_pci_tbl,
	.probe			= oldpiix_init_one,
	.remove			= ata_pci_remove_one,
};

static int __init oldpiix_init(void)
{
	return pci_register_driver(&oldpiix_pci_driver);
}

static void __exit oldpiix_exit(void)
{
	pci_unregister_driver(&oldpiix_pci_driver);
}


module_init(oldpiix_init);
module_exit(oldpiix_exit);

MODULE_AUTHOR("Alan Cox");
MODULE_DESCRIPTION("SCSI low-level driver for early PIIX series controllers");
MODULE_LICENSE("GPL");
MODULE_DEVICE_TABLE(pci, oldpiix_pci_tbl);
MODULE_VERSION(DRV_VERSION);