/*
 * cmd64x.c: Enable interrupts at initialization time on Ultra/PCI machines.
 *           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>
 * Copyright (C) 2007-2010      Bartlomiej Zolnierkiewicz
 * Copyright (C) 2007,2009      MontaVista Software, Inc. <source@mvista.com>
 */

#include <linux/module.h>
#include <linux/types.h>
#include <linux/pci.h>
#include <linux/ide.h>
#include <linux/init.h>

#include <asm/io.h>

#define DRV_NAME "cmd64x"

/*
 * CMD64x specific registers definition.
 */
#define CFR             0x50
#define   CFR_INTR_CH0          0x04

#define CMDTIM          0x52
#define ARTTIM0         0x53
#define DRWTIM0         0x54
#define ARTTIM1         0x55
#define DRWTIM1         0x56
#define ARTTIM23        0x57
#define   ARTTIM23_DIS_RA2      0x04
#define   ARTTIM23_DIS_RA3      0x08
#define   ARTTIM23_INTR_CH1     0x10
#define DRWTIM2         0x58
#define BRST            0x59
#define DRWTIM3         0x5b

#define BMIDECR0        0x70
#define MRDMODE         0x71
#define   MRDMODE_INTR_CH0      0x04
#define   MRDMODE_INTR_CH1      0x08
#define UDIDETCR0       0x73
#define DTPR0           0x74
#define BMIDECR1        0x78
#define BMIDECSR        0x79
#define UDIDETCR1       0x7B
#define DTPR1           0x7C

static void cmd64x_program_timings(ide_drive_t *drive, u8 mode)
{
        ide_hwif_t *hwif = drive->hwif;
        struct pci_dev *dev = to_pci_dev(drive->hwif->dev);
        int bus_speed = ide_pci_clk ? ide_pci_clk : 33;
        const unsigned long T = 1000000 / bus_speed;
        static const u8 recovery_values[] =
                {15, 15, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 0};
        static const u8 setup_values[] = {0x40, 0x40, 0x40, 0x80, 0, 0xc0};
        static const u8 arttim_regs[4] = {ARTTIM0, ARTTIM1, ARTTIM23, ARTTIM23};
        static const u8 drwtim_regs[4] = {DRWTIM0, DRWTIM1, DRWTIM2, DRWTIM3};
        struct ide_timing t;
        u8 arttim = 0;

        ide_timing_compute(drive, mode, &t, T, 0);

        /*
         * In case we've got too long recovery phase, try to lengthen
         * the active phase
         */
        if (t.recover > 16) {
                t.active += t.recover - 16;
                t.recover = 16;
        }
        if (t.active > 16)              /* shouldn't actually happen... */
                t.active = 16;

        /*
         * Convert values to internal chipset representation
         */
        t.recover = recovery_values[t.recover];
        t.active &= 0x0f;

        /* Program the active/recovery counts into the DRWTIM register */
        pci_write_config_byte(dev, drwtim_regs[drive->dn],
                              (t.active << 4) | t.recover);

        /*
         * The primary channel has individual address setup timing registers
         * for each drive and the hardware selects the slowest timing itself.
         * The secondary channel has one common register and we have to select
         * the slowest address setup timing ourselves.
         */
        if (hwif->channel) {
                ide_drive_t *pair = ide_get_pair_dev(drive);

                if (pair) {
                        struct ide_timing tp;

                        ide_timing_compute(pair, pair->pio_mode, &tp, T, 0);
                        ide_timing_merge(&t, &tp, &t, IDE_TIMING_SETUP);
                        if (pair->dma_mode) {
                                ide_timing_compute(pair, pair->dma_mode,
                                                &tp, T, 0);
                                ide_timing_merge(&tp, &t, &t, IDE_TIMING_SETUP);
                        }
                }
        }

        if (t.setup > 5)                /* shouldn't actually happen... */
                t.setup = 5;

        /*
         * Program the address setup clocks into the ARTTIM registers.
         * Avoid clearing the secondary channel's interrupt bit.
         */
        (void) pci_read_config_byte (dev, arttim_regs[drive->dn], &arttim);
        if (hwif->channel)
                arttim &= ~ARTTIM23_INTR_CH1;
        arttim &= ~0xc0;
        arttim |= setup_values[t.setup];
        (void) pci_write_config_byte(dev, arttim_regs[drive->dn], arttim);
}

/*
 * Attempts to set drive's PIO mode.
 * Special cases are 8: prefetch off, 9: prefetch on (both never worked)
 */

static void cmd64x_set_pio_mode(ide_hwif_t *hwif, ide_drive_t *drive)
{
        const u8 pio = drive->pio_mode - XFER_PIO_0;

        /*
         * Filter out the prefetch control values
         * to prevent PIO5 from being programmed
         */
        if (pio == 8 || pio == 9)
                return;

        cmd64x_program_timings(drive, XFER_PIO_0 + pio);
}

static void cmd64x_set_dma_mode(ide_hwif_t *hwif, ide_drive_t *drive)
{
        struct pci_dev *dev     = to_pci_dev(hwif->dev);
        u8 unit                 = drive->dn & 0x01;
        u8 regU = 0, pciU       = hwif->channel ? UDIDETCR1 : UDIDETCR0;
        const u8 speed          = drive->dma_mode;

        pci_read_config_byte(dev, pciU, &regU);
        regU &= ~(unit ? 0xCA : 0x35);

        switch(speed) {
        case XFER_UDMA_5:
                regU |= unit ? 0x0A : 0x05;
                break;
        case XFER_UDMA_4:
                regU |= unit ? 0x4A : 0x15;
                break;
        case XFER_UDMA_3:
                regU |= unit ? 0x8A : 0x25;
                break;
        case XFER_UDMA_2:
                regU |= unit ? 0x42 : 0x11;
                break;
        case XFER_UDMA_1:
                regU |= unit ? 0x82 : 0x21;
                break;
        case XFER_UDMA_0:
                regU |= unit ? 0xC2 : 0x31;
                break;
        case XFER_MW_DMA_2:
        case XFER_MW_DMA_1:
        case XFER_MW_DMA_0:
                cmd64x_program_timings(drive, speed);
                break;
        }

        pci_write_config_byte(dev, pciU, regU);
}

static void cmd648_clear_irq(ide_drive_t *drive)
{
        ide_hwif_t *hwif        = drive->hwif;
        struct pci_dev *dev     = to_pci_dev(hwif->dev);
        unsigned long base      = pci_resource_start(dev, 4);
        u8  irq_mask            = hwif->channel ? MRDMODE_INTR_CH1 :
                                                  MRDMODE_INTR_CH0;
        u8  mrdmode             = inb(base + 1);

        /* clear the interrupt bit */
        outb((mrdmode & ~(MRDMODE_INTR_CH0 | MRDMODE_INTR_CH1)) | irq_mask,
             base + 1);
}

static void cmd64x_clear_irq(ide_drive_t *drive)
{
        ide_hwif_t *hwif        = drive->hwif;
        struct pci_dev *dev     = to_pci_dev(hwif->dev);
        int irq_reg             = hwif->channel ? ARTTIM23 : CFR;
        u8  irq_mask            = hwif->channel ? ARTTIM23_INTR_CH1 :
                                                  CFR_INTR_CH0;
        u8  irq_stat            = 0;

        (void) pci_read_config_byte(dev, irq_reg, &irq_stat);
        /* clear the interrupt bit */
        (void) pci_write_config_byte(dev, irq_reg, irq_stat | irq_mask);
}

static int cmd648_test_irq(ide_hwif_t *hwif)
{
        struct pci_dev *dev     = to_pci_dev(hwif->dev);
        unsigned long base      = pci_resource_start(dev, 4);
        u8 irq_mask             = hwif->channel ? MRDMODE_INTR_CH1 :
                                                  MRDMODE_INTR_CH0;
        u8 mrdmode              = inb(base + 1);

        pr_debug("%s: mrdmode: 0x%02x irq_mask: 0x%02x\n",
                 hwif->name, mrdmode, irq_mask);

        return (mrdmode & irq_mask) ? 1 : 0;
}

static int cmd64x_test_irq(ide_hwif_t *hwif)
{
        struct pci_dev *dev     = to_pci_dev(hwif->dev);
        int irq_reg             = hwif->channel ? ARTTIM23 : CFR;
        u8  irq_mask            = hwif->channel ? ARTTIM23_INTR_CH1 :
                                                  CFR_INTR_CH0;
        u8  irq_stat            = 0;

        (void) pci_read_config_byte(dev, irq_reg, &irq_stat);

        pr_debug("%s: irq_stat: 0x%02x irq_mask: 0x%02x\n",
                 hwif->name, irq_stat, irq_mask);

        return (irq_stat & irq_mask) ? 1 : 0;
}

/*
 * ASUS P55T2P4D with CMD646 chipset revision 0x01 requires the old
 * event order for DMA transfers.
 */

static int cmd646_1_dma_end(ide_drive_t *drive)
{
        ide_hwif_t *hwif = drive->hwif;
        u8 dma_stat = 0, dma_cmd = 0;

        /* get DMA status */
        dma_stat = inb(hwif->dma_base + ATA_DMA_STATUS);
        /* read DMA command state */
        dma_cmd = inb(hwif->dma_base + ATA_DMA_CMD);
        /* stop DMA */
        outb(dma_cmd & ~1, hwif->dma_base + ATA_DMA_CMD);
        /* clear the INTR & ERROR bits */
        outb(dma_stat | 6, hwif->dma_base + ATA_DMA_STATUS);
        /* verify good DMA status */
        return (dma_stat & 7) != 4;
}

static int init_chipset_cmd64x(struct pci_dev *dev)
{
        u8 mrdmode = 0;

        /* Set a good latency timer and cache line size value. */
        (void) pci_write_config_byte(dev, PCI_LATENCY_TIMER, 64);
        /* FIXME: pci_set_master() to ensure a good latency timer value */

        /*
         * Enable interrupts, select MEMORY READ LINE for reads.
         *
         * NOTE: although not mentioned in the PCI0646U specs,
         * bits 0-1 are write only and won't be read back as
         * set or not -- PCI0646U2 specs clarify this point.
         */
        (void) pci_read_config_byte (dev, MRDMODE, &mrdmode);
        mrdmode &= ~0x30;
        (void) pci_write_config_byte(dev, MRDMODE, (mrdmode | 0x02));

        return 0;
}

static u8 cmd64x_cable_detect(ide_hwif_t *hwif)
{
        struct pci_dev  *dev    = to_pci_dev(hwif->dev);
        u8 bmidecsr = 0, mask   = hwif->channel ? 0x02 : 0x01;

        switch (dev->device) {
        case PCI_DEVICE_ID_CMD_648:
        case PCI_DEVICE_ID_CMD_649:
                pci_read_config_byte(dev, BMIDECSR, &bmidecsr);
                return (bmidecsr & mask) ? ATA_CBL_PATA80 : ATA_CBL_PATA40;
        default:
                return ATA_CBL_PATA40;
        }
}

static const struct ide_port_ops cmd64x_port_ops = {
        .set_pio_mode           = cmd64x_set_pio_mode,
        .set_dma_mode           = cmd64x_set_dma_mode,
        .clear_irq              = cmd64x_clear_irq,
        .test_irq               = cmd64x_test_irq,
        .cable_detect           = cmd64x_cable_detect,
};

static const struct ide_port_ops cmd648_port_ops = {
        .set_pio_mode           = cmd64x_set_pio_mode,
        .set_dma_mode           = cmd64x_set_dma_mode,
        .clear_irq              = cmd648_clear_irq,
        .test_irq               = cmd648_test_irq,
        .cable_detect           = cmd64x_cable_detect,
};

static const struct ide_dma_ops cmd646_rev1_dma_ops = {
        .dma_host_set           = ide_dma_host_set,
        .dma_setup              = ide_dma_setup,
        .dma_start              = ide_dma_start,
        .dma_end                = cmd646_1_dma_end,
        .dma_test_irq           = ide_dma_test_irq,
        .dma_lost_irq           = ide_dma_lost_irq,
        .dma_timer_expiry       = ide_dma_sff_timer_expiry,
        .dma_sff_read_status    = ide_dma_sff_read_status,
};

static const struct ide_port_info cmd64x_chipsets[] = {
        {       /* 0: CMD643 */
                .name           = DRV_NAME,
                .init_chipset   = init_chipset_cmd64x,
                .enablebits     = {{0x00,0x00,0x00}, {0x51,0x08,0x08}},
                .port_ops       = &cmd64x_port_ops,
                .host_flags     = IDE_HFLAG_CLEAR_SIMPLEX |
                                  IDE_HFLAG_ABUSE_PREFETCH |
                                  IDE_HFLAG_SERIALIZE,
                .pio_mask       = ATA_PIO5,
                .mwdma_mask     = ATA_MWDMA2,
                .udma_mask      = 0x00, /* no udma */
        },
        {       /* 1: CMD646 */
                .name           = DRV_NAME,
                .init_chipset   = init_chipset_cmd64x,
                .enablebits     = {{0x51,0x04,0x04}, {0x51,0x08,0x08}},
                .port_ops       = &cmd648_port_ops,
                .host_flags     = IDE_HFLAG_ABUSE_PREFETCH |
                                  IDE_HFLAG_SERIALIZE,
                .pio_mask       = ATA_PIO5,
                .mwdma_mask     = ATA_MWDMA2,
                .udma_mask      = ATA_UDMA2,
        },
        {       /* 2: CMD648 */
                .name           = DRV_NAME,
                .init_chipset   = init_chipset_cmd64x,
                .enablebits     = {{0x51,0x04,0x04}, {0x51,0x08,0x08}},
                .port_ops       = &cmd648_port_ops,
                .host_flags     = IDE_HFLAG_ABUSE_PREFETCH,
                .pio_mask       = ATA_PIO5,
                .mwdma_mask     = ATA_MWDMA2,
                .udma_mask      = ATA_UDMA4,
        },
        {       /* 3: CMD649 */
                .name           = DRV_NAME,
                .init_chipset   = init_chipset_cmd64x,
                .enablebits     = {{0x51,0x04,0x04}, {0x51,0x08,0x08}},
                .port_ops       = &cmd648_port_ops,
                .host_flags     = IDE_HFLAG_ABUSE_PREFETCH,
                .pio_mask       = ATA_PIO5,
                .mwdma_mask     = ATA_MWDMA2,
                .udma_mask      = ATA_UDMA5,
        }
};

static int cmd64x_init_one(struct pci_dev *dev, const struct pci_device_id *id)
{
        struct ide_port_info d;
        u8 idx = id->driver_data;

        d = cmd64x_chipsets[idx];

        if (idx == 1) {
                /*
                 * UltraDMA only supported on PCI646U and PCI646U2, which
                 * correspond to revisions 0x03, 0x05 and 0x07 respectively.
                 * Actually, although the CMD tech support people won't
                 * tell me the details, the 0x03 revision cannot support
                 * UDMA correctly without hardware modifications, and even
                 * then it only works with Quantum disks due to some
                 * hold time assumptions in the 646U part which are fixed
                 * in the 646U2.
                 *
                 * So we only do UltraDMA on revision 0x05 and 0x07 chipsets.
                 */
                if (dev->revision < 5) {
                        d.udma_mask = 0x00;
                        /*
                         * The original PCI0646 didn't have the primary
                         * channel enable bit, it appeared starting with
                         * PCI0646U (i.e. revision ID 3).
                         */
                        if (dev->revision < 3) {
                                d.enablebits[0].reg = 0;
                                d.port_ops = &cmd64x_port_ops;
                                if (dev->revision == 1)
                                        d.dma_ops = &cmd646_rev1_dma_ops;
                        }
                }
        }

        return ide_pci_init_one(dev, &d, NULL);
}

static const struct pci_device_id cmd64x_pci_tbl[] = {
        { 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), 2 },
        { PCI_VDEVICE(CMD, PCI_DEVICE_ID_CMD_649), 3 },
        { 0, },
};
MODULE_DEVICE_TABLE(pci, cmd64x_pci_tbl);

static struct pci_driver cmd64x_pci_driver = {
        .name           = "CMD64x_IDE",
        .id_table       = cmd64x_pci_tbl,
        .probe          = cmd64x_init_one,
        .remove         = ide_pci_remove,
        .suspend        = ide_pci_suspend,
        .resume         = ide_pci_resume,
};

static int __init cmd64x_ide_init(void)
{
        return ide_pci_register_driver(&cmd64x_pci_driver);
}

static void __exit cmd64x_ide_exit(void)
{
        pci_unregister_driver(&cmd64x_pci_driver);
}

module_init(cmd64x_ide_init);
module_exit(cmd64x_ide_exit);

MODULE_AUTHOR("Eddie Dost, David Miller, Andre Hedrick, Bartlomiej Zolnierkiewicz");
MODULE_DESCRIPTION("PCI driver module for CMD64x IDE");
MODULE_LICENSE("GPL");