/*
 *      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     "0.6.6"

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 = ioread8(ap->ioaddr.bmdma_addr + 0x02);
        reg |= 1<<(adev->devno + 5);
        iowrite8(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 struct scsi_host_template cs5520_sht = {
        ATA_BMDMA_SHT(DRV_NAME),
        .sg_tablesize           = LIBATA_DUMB_MAX_PRD,
};

static struct ata_port_operations cs5520_port_ops = {
        .inherits               = &ata_bmdma_port_ops,
        .qc_prep                = ata_sff_dumb_qc_prep,
        .cable_detect           = ata_cable_40wire,
        .set_piomode            = cs5520_set_piomode,
        .set_dmamode            = cs5520_set_dmamode,
};

static int __devinit cs5520_init_one(struct pci_dev *pdev, const struct pci_device_id *id)
{
        static const unsigned int cmd_port[] = { 0x1F0, 0x170 };
        static const unsigned int ctl_port[] = { 0x3F6, 0x376 };
        struct ata_port_info pi = {
                .flags          = ATA_FLAG_SLAVE_POSS,
                .pio_mask       = ATA_PIO4,
                .port_ops       = &cs5520_port_ops,
        };
        const struct ata_port_info *ppi[2];
        u8 pcicfg;
        void __iomem *iomap[5];
        struct ata_host *host;
        struct ata_ioports *ioaddr;
        int i, rc;

        rc = pcim_enable_device(pdev);
        if (rc)
                return rc;

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

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

        ppi[0] = ppi[1] = &ata_dummy_port_info;
        if (pcicfg & 1)
                ppi[0] = &pi;
        if (pcicfg & 2)
                ppi[1] = &pi;

        if ((pcicfg & 0x40) == 0) {
                dev_printk(KERN_WARNING, &pdev->dev,
                           "DMA mode disabled. Enabling.\n");
                pci_write_config_byte(pdev, 0x60, pcicfg | 0x40);
        }

        pi.mwdma_mask = id->driver_data;

        host = ata_host_alloc_pinfo(&pdev->dev, ppi, 2);
        if (!host)
                return -ENOMEM;

        /* Perform set up for DMA */
        if (pci_enable_device_io(pdev)) {
                printk(KERN_ERR DRV_NAME ": unable to configure BAR2.\n");
                return -ENODEV;
        }

        if (pci_set_dma_mask(pdev, DMA_BIT_MASK(32))) {
                printk(KERN_ERR DRV_NAME ": unable to configure DMA mask.\n");
                return -ENODEV;
        }
        if (pci_set_consistent_dma_mask(pdev, DMA_BIT_MASK(32))) {
                printk(KERN_ERR DRV_NAME ": unable to configure consistent DMA mask.\n");
                return -ENODEV;
        }

        /* Map IO ports and initialize host accordingly */
        iomap[0] = devm_ioport_map(&pdev->dev, cmd_port[0], 8);
        iomap[1] = devm_ioport_map(&pdev->dev, ctl_port[0], 1);
        iomap[2] = devm_ioport_map(&pdev->dev, cmd_port[1], 8);
        iomap[3] = devm_ioport_map(&pdev->dev, ctl_port[1], 1);
        iomap[4] = pcim_iomap(pdev, 2, 0);

        if (!iomap[0] || !iomap[1] || !iomap[2] || !iomap[3] || !iomap[4])
                return -ENOMEM;

        ioaddr = &host->ports[0]->ioaddr;
        ioaddr->cmd_addr = iomap[0];
        ioaddr->ctl_addr = iomap[1];
        ioaddr->altstatus_addr = iomap[1];
        ioaddr->bmdma_addr = iomap[4];
        ata_sff_std_ports(ioaddr);

        ata_port_desc(host->ports[0],
                      "cmd 0x%x ctl 0x%x", cmd_port[0], ctl_port[0]);
        ata_port_pbar_desc(host->ports[0], 4, 0, "bmdma");

        ioaddr = &host->ports[1]->ioaddr;
        ioaddr->cmd_addr = iomap[2];
        ioaddr->ctl_addr = iomap[3];
        ioaddr->altstatus_addr = iomap[3];
        ioaddr->bmdma_addr = iomap[4] + 8;
        ata_sff_std_ports(ioaddr);

        ata_port_desc(host->ports[1],
                      "cmd 0x%x ctl 0x%x", cmd_port[1], ctl_port[1]);
        ata_port_pbar_desc(host->ports[1], 4, 8, "bmdma");

        /* activate the host */
        pci_set_master(pdev);
        rc = ata_host_start(host);
        if (rc)
                return rc;

        for (i = 0; i < 2; i++) {
                static const int irq[] = { 14, 15 };
                struct ata_port *ap = host->ports[i];

                if (ata_port_is_dummy(ap))
                        continue;

                rc = devm_request_irq(&pdev->dev, irq[ap->port_no],
                                      ata_sff_interrupt, 0, DRV_NAME, host);
                if (rc)
                        return rc;

                ata_port_desc(ap, "irq %d", irq[i]);
        }

        return ata_host_register(host, &cs5520_sht);
}

#ifdef CONFIG_PM
/**
 *      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)
{
        struct ata_host *host = dev_get_drvdata(&pdev->dev);
        u8 pcicfg;
        int rc;

        rc = ata_pci_device_do_resume(pdev);
        if (rc)
                return rc;

        pci_read_config_byte(pdev, 0x60, &pcicfg);
        if ((pcicfg & 0x40) == 0)
                pci_write_config_byte(pdev, 0x60, pcicfg | 0x40);

        ata_host_resume(host);
        return 0;
}

/**
 *      cs5520_pci_device_suspend       -       device suspend
 *      @pdev: PCI device
 *
 *      We have to cut and waste bits from the standard method because
 *      the 5520 is a bit odd and not just a pure ATA device. As a result
 *      we must not disable it. The needed code is short and this avoids
 *      chip specific mess in the core code.
 */

static int cs5520_pci_device_suspend(struct pci_dev *pdev, pm_message_t mesg)
{
        struct ata_host *host = dev_get_drvdata(&pdev->dev);
        int rc = 0;

        rc = ata_host_suspend(host, mesg);
        if (rc)
                return rc;

        pci_save_state(pdev);
        return 0;
}
#endif /* CONFIG_PM */

/* 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         = ata_pci_remove_one,
#ifdef CONFIG_PM
        .suspend        = cs5520_pci_device_suspend,
        .resume         = cs5520_reinit_one,
#endif
};

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);