/*
 *	IDE tuning and bus mastering support for the CS5510/CS5520
 *	chipsets
 *
 *	The CS5510/CS5520 are slightly unusual devices. Unlike the
 *	typical IDE controllers they do bus mastering with the drive in
 *	PIO mode and smarter silicon.
 *
 *	The practical upshot of this is that we must always tune the
 *	drive for the right PIO mode. We must also ignore all the blacklists
 *	and the drive bus mastering DMA information. Also to confuse matters
 *	further we can do DMA on PIO only drives.
 *
 *	DMA on the 5510 also requires we disable_hlt() during DMA on early
 *	revisions.
 *
 *	*** This driver is strictly experimental ***
 *
 *	(c) Copyright Red Hat Inc 2002
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License as published by the
 * Free Software Foundation; either version 2, or (at your option) any
 * later version.
 *
 * This program is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * General Public License for more details.
 *
 * Documentation:
 *	Not publically available.
 */
#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 <scsi/scsi_host.h>
#include <linux/libata.h>

#define DRV_NAME	"pata_cs5520"
#define DRV_VERSION	"0.6.3"

struct pio_clocks
{
	int address;
	int assert;
	int recovery;
};

static const struct pio_clocks cs5520_pio_clocks[]={
	{3, 6, 11},
	{2, 5, 6},
	{1, 4, 3},
	{1, 3, 2},
	{1, 2, 1}
};

/**
 *	cs5520_set_timings	-	program PIO timings
 *	@ap: ATA port
 *	@adev: ATA device
 *
 *	Program the PIO mode timings for the controller according to the pio
 *	clocking table.
 */

static void cs5520_set_timings(struct ata_port *ap, struct ata_device *adev, int pio)
{
	struct pci_dev *pdev = to_pci_dev(ap->host->dev);
	int slave = adev->devno;

	pio -= XFER_PIO_0;

	/* Channel command timing */
	pci_write_config_byte(pdev, 0x62 + ap->port_no,
				(cs5520_pio_clocks[pio].recovery << 4) |
				(cs5520_pio_clocks[pio].assert));
	/* FIXME: should these use address ? */
	/* Read command timing */
	pci_write_config_byte(pdev, 0x64 +  4*ap->port_no + slave,
				(cs5520_pio_clocks[pio].recovery << 4) |
				(cs5520_pio_clocks[pio].assert));
	/* Write command timing */
	pci_write_config_byte(pdev, 0x66 +  4*ap->port_no + slave,
				(cs5520_pio_clocks[pio].recovery << 4) |
				(cs5520_pio_clocks[pio].assert));
}

/**
 *	cs5520_enable_dma	-	turn on DMA bits
 *
 *	Turn on the DMA bits for this disk. Needed because the BIOS probably
 *	has not done the work for us. Belongs in the core SATA code.
 */

static void cs5520_enable_dma(struct ata_port *ap, struct ata_device *adev)
{
	/* Set the DMA enable/disable flag */
	u8 reg = inb(ap->ioaddr.bmdma_addr + 0x02);
	reg |= 1<<(adev->devno + 5);
	outb(reg, ap->ioaddr.bmdma_addr + 0x02);
}

/**
 *	cs5520_set_dmamode	-	program DMA timings
 *	@ap: ATA port
 *	@adev: ATA device
 *
 *	Program the DMA mode timings for the controller according to the pio
 *	clocking table. Note that this device sets the DMA timings to PIO
 *	mode values. This may seem bizarre but the 5520 architecture talks
 *	PIO mode to the disk and DMA mode to the controller so the underlying
 *	transfers are PIO timed.
 */

static void cs5520_set_dmamode(struct ata_port *ap, struct ata_device *adev)
{
	static const int dma_xlate[3] = { XFER_PIO_0, XFER_PIO_3, XFER_PIO_4 };
	cs5520_set_timings(ap, adev, dma_xlate[adev->dma_mode]);
	cs5520_enable_dma(ap, adev);
}

/**
 *	cs5520_set_piomode	-	program PIO timings
 *	@ap: ATA port
 *	@adev: ATA device
 *
 *	Program the PIO mode timings for the controller according to the pio
 *	clocking table. We know pio_mode will equal dma_mode because of the
 *	CS5520 architecture. At least once we turned DMA on and wrote a
 *	mode setter.
 */

static void cs5520_set_piomode(struct ata_port *ap, struct ata_device *adev)
{
	cs5520_set_timings(ap, adev, adev->pio_mode);
}


static int cs5520_pre_reset(struct ata_port *ap)
{
	ap->cbl = ATA_CBL_PATA40;
	return ata_std_prereset(ap);
}

static void cs5520_error_handler(struct ata_port *ap)
{
	return ata_bmdma_drive_eh(ap, cs5520_pre_reset, ata_std_softreset, NULL, ata_std_postreset);
}

static struct scsi_host_template cs5520_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,
	.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,
	.slave_destroy		= ata_scsi_slave_destroy,
	.bios_param		= ata_std_bios_param,
	.resume			= ata_scsi_device_resume,
	.suspend		= ata_scsi_device_suspend,
};

static struct ata_port_operations cs5520_port_ops = {
	.port_disable		= ata_port_disable,
	.set_piomode		= cs5520_set_piomode,
	.set_dmamode		= cs5520_set_dmamode,

	.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		= cs5520_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		= ata_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,
};

static int __devinit cs5520_init_one(struct pci_dev *dev, const struct pci_device_id *id)
{
	u8 pcicfg;
	static struct ata_probe_ent probe[2];
	int ports = 0;

	/* IDE port enable bits */
	pci_read_config_byte(dev, 0x60, &pcicfg);

	/* Check if the ATA ports are enabled */
	if ((pcicfg & 3) == 0)
		return -ENODEV;

	if ((pcicfg & 0x40) == 0) {
		printk(KERN_WARNING DRV_NAME ": DMA mode disabled. Enabling.\n");
		pci_write_config_byte(dev, 0x60, pcicfg | 0x40);
	}

	/* Perform set up for DMA */
	if (pci_enable_device_bars(dev, 1<<2)) {
		printk(KERN_ERR DRV_NAME ": unable to configure BAR2.\n");
		return -ENODEV;
	}
	pci_set_master(dev);
	if (pci_set_dma_mask(dev, DMA_32BIT_MASK)) {
		printk(KERN_ERR DRV_NAME ": unable to configure DMA mask.\n");
		return -ENODEV;
	}
	if (pci_set_consistent_dma_mask(dev, DMA_32BIT_MASK)) {
		printk(KERN_ERR DRV_NAME ": unable to configure consistent DMA mask.\n");
		return -ENODEV;
	}

	/* We have to do our own plumbing as the PCI setup for this
	   chipset is non-standard so we can't punt to the libata code */

	INIT_LIST_HEAD(&probe[0].node);
	probe[0].dev = pci_dev_to_dev(dev);
	probe[0].port_ops = &cs5520_port_ops;
	probe[0].sht = &cs5520_sht;
	probe[0].pio_mask = 0x1F;
	probe[0].mwdma_mask = id->driver_data;
	probe[0].irq = 14;
	probe[0].irq_flags = 0;
	probe[0].port_flags = ATA_FLAG_SLAVE_POSS|ATA_FLAG_SRST;
	probe[0].n_ports = 1;
	probe[0].port[0].cmd_addr = 0x1F0;
	probe[0].port[0].ctl_addr = 0x3F6;
	probe[0].port[0].altstatus_addr = 0x3F6;
	probe[0].port[0].bmdma_addr = pci_resource_start(dev, 2);

	/* The secondary lurks at different addresses but is otherwise
	   the same beastie */

	probe[1] = probe[0];
	INIT_LIST_HEAD(&probe[1].node);
	probe[1].irq = 15;
	probe[1].port[0].cmd_addr = 0x170;
	probe[1].port[0].ctl_addr = 0x376;
	probe[1].port[0].altstatus_addr = 0x376;
	probe[1].port[0].bmdma_addr = pci_resource_start(dev, 2) + 8;

	/* Let libata fill in the port details */
	ata_std_ports(&probe[0].port[0]);
	ata_std_ports(&probe[1].port[0]);

	/* Now add the ports that are active */
	if (pcicfg & 1)
		ports += ata_device_add(&probe[0]);
	if (pcicfg & 2)
		ports += ata_device_add(&probe[1]);
	if (ports)
		return 0;
	return -ENODEV;
}

/**
 *	cs5520_remove_one	-	device unload
 *	@pdev: PCI device being removed
 *
 *	Handle an unplug/unload event for a PCI device. Unload the
 *	PCI driver but do not use the default handler as we manage
 *	resources ourself and *MUST NOT* disable the device as it has
 *	other functions.
 */

static void __devexit cs5520_remove_one(struct pci_dev *pdev)
{
	struct device *dev = pci_dev_to_dev(pdev);
	struct ata_host *host = dev_get_drvdata(dev);

	ata_host_remove(host);
	dev_set_drvdata(dev, NULL);
}

/**
 *	cs5520_reinit_one	-	device resume
 *	@pdev: PCI device
 *
 *	Do any reconfiguration work needed by a resume from RAM. We need
 *	to restore DMA mode support on BIOSen which disabled it
 */
 
static int cs5520_reinit_one(struct pci_dev *pdev)
{
	u8 pcicfg;
	pci_read_config_byte(pdev, 0x60, &pcicfg);
	if ((pcicfg & 0x40) == 0)
		pci_write_config_byte(pdev, 0x60, pcicfg | 0x40);
	return ata_pci_device_resume(pdev);
}
/* For now keep DMA off. We can set it for all but A rev CS5510 once the
   core ATA code can handle it */

static const struct pci_device_id pata_cs5520[] = {
	{ PCI_VDEVICE(CYRIX, PCI_DEVICE_ID_CYRIX_5510), },
	{ PCI_VDEVICE(CYRIX, PCI_DEVICE_ID_CYRIX_5520), },

	{ },
};

static struct pci_driver cs5520_pci_driver = {
	.name 		= DRV_NAME,
	.id_table	= pata_cs5520,
	.probe 		= cs5520_init_one,
	.remove		= cs5520_remove_one,
	.suspend	= ata_pci_device_suspend,
	.resume		= cs5520_reinit_one,
};

static int __init cs5520_init(void)
{
	return pci_register_driver(&cs5520_pci_driver);
}

static void __exit cs5520_exit(void)
{
	pci_unregister_driver(&cs5520_pci_driver);
}

MODULE_AUTHOR("Alan Cox");
MODULE_DESCRIPTION("low-level driver for Cyrix CS5510/5520");
MODULE_LICENSE("GPL");
MODULE_DEVICE_TABLE(pci, pata_cs5520);
MODULE_VERSION(DRV_VERSION);

module_init(cs5520_init);
module_exit(cs5520_exit);