// SPDX-License-Identifier: GPL-2.0-only
/*
 * Copyright (c) 1996-2004 Russell King.
 *
 * Please note that this platform does not support 32-bit IDE IO.
 */

#include <linux/string.h>
#include <linux/module.h>
#include <linux/ioport.h>
#include <linux/slab.h>
#include <linux/blkdev.h>
#include <linux/errno.h>
#include <linux/ide.h>
#include <linux/dma-mapping.h>
#include <linux/device.h>
#include <linux/init.h>
#include <linux/scatterlist.h>
#include <linux/io.h>

#include <asm/dma.h>
#include <asm/ecard.h>

#define DRV_NAME "icside"

#define ICS_IDENT_OFFSET                0x2280

#define ICS_ARCIN_V5_INTRSTAT           0x0000
#define ICS_ARCIN_V5_INTROFFSET         0x0004
#define ICS_ARCIN_V5_IDEOFFSET          0x2800
#define ICS_ARCIN_V5_IDEALTOFFSET       0x2b80
#define ICS_ARCIN_V5_IDESTEPPING        6

#define ICS_ARCIN_V6_IDEOFFSET_1        0x2000
#define ICS_ARCIN_V6_INTROFFSET_1       0x2200
#define ICS_ARCIN_V6_INTRSTAT_1         0x2290
#define ICS_ARCIN_V6_IDEALTOFFSET_1     0x2380
#define ICS_ARCIN_V6_IDEOFFSET_2        0x3000
#define ICS_ARCIN_V6_INTROFFSET_2       0x3200
#define ICS_ARCIN_V6_INTRSTAT_2         0x3290
#define ICS_ARCIN_V6_IDEALTOFFSET_2     0x3380
#define ICS_ARCIN_V6_IDESTEPPING        6

struct cardinfo {
        unsigned int dataoffset;
        unsigned int ctrloffset;
        unsigned int stepping;
};

static struct cardinfo icside_cardinfo_v5 = {
        .dataoffset     = ICS_ARCIN_V5_IDEOFFSET,
        .ctrloffset     = ICS_ARCIN_V5_IDEALTOFFSET,
        .stepping       = ICS_ARCIN_V5_IDESTEPPING,
};

static struct cardinfo icside_cardinfo_v6_1 = {
        .dataoffset     = ICS_ARCIN_V6_IDEOFFSET_1,
        .ctrloffset     = ICS_ARCIN_V6_IDEALTOFFSET_1,
        .stepping       = ICS_ARCIN_V6_IDESTEPPING,
};

static struct cardinfo icside_cardinfo_v6_2 = {
        .dataoffset     = ICS_ARCIN_V6_IDEOFFSET_2,
        .ctrloffset     = ICS_ARCIN_V6_IDEALTOFFSET_2,
        .stepping       = ICS_ARCIN_V6_IDESTEPPING,
};

struct icside_state {
        unsigned int channel;
        unsigned int enabled;
        void __iomem *irq_port;
        void __iomem *ioc_base;
        unsigned int sel;
        unsigned int type;
        struct ide_host *host;
};

#define ICS_TYPE_A3IN   0
#define ICS_TYPE_A3USER 1
#define ICS_TYPE_V6     3
#define ICS_TYPE_V5     15
#define ICS_TYPE_NOTYPE ((unsigned int)-1)

/* ---------------- Version 5 PCB Support Functions --------------------- */
/* Prototype: icside_irqenable_arcin_v5 (struct expansion_card *ec, int irqnr)
 * Purpose  : enable interrupts from card
 */
static void icside_irqenable_arcin_v5 (struct expansion_card *ec, int irqnr)
{
        struct icside_state *state = ec->irq_data;

        writeb(0, state->irq_port + ICS_ARCIN_V5_INTROFFSET);
}

/* Prototype: icside_irqdisable_arcin_v5 (struct expansion_card *ec, int irqnr)
 * Purpose  : disable interrupts from card
 */
static void icside_irqdisable_arcin_v5 (struct expansion_card *ec, int irqnr)
{
        struct icside_state *state = ec->irq_data;

        readb(state->irq_port + ICS_ARCIN_V5_INTROFFSET);
}

static const expansioncard_ops_t icside_ops_arcin_v5 = {
        .irqenable      = icside_irqenable_arcin_v5,
        .irqdisable     = icside_irqdisable_arcin_v5,
};


/* ---------------- Version 6 PCB Support Functions --------------------- */
/* Prototype: icside_irqenable_arcin_v6 (struct expansion_card *ec, int irqnr)
 * Purpose  : enable interrupts from card
 */
static void icside_irqenable_arcin_v6 (struct expansion_card *ec, int irqnr)
{
        struct icside_state *state = ec->irq_data;
        void __iomem *base = state->irq_port;

        state->enabled = 1;

        switch (state->channel) {
        case 0:
                writeb(0, base + ICS_ARCIN_V6_INTROFFSET_1);
                readb(base + ICS_ARCIN_V6_INTROFFSET_2);
                break;
        case 1:
                writeb(0, base + ICS_ARCIN_V6_INTROFFSET_2);
                readb(base + ICS_ARCIN_V6_INTROFFSET_1);
                break;
        }
}

/* Prototype: icside_irqdisable_arcin_v6 (struct expansion_card *ec, int irqnr)
 * Purpose  : disable interrupts from card
 */
static void icside_irqdisable_arcin_v6 (struct expansion_card *ec, int irqnr)
{
        struct icside_state *state = ec->irq_data;

        state->enabled = 0;

        readb(state->irq_port + ICS_ARCIN_V6_INTROFFSET_1);
        readb(state->irq_port + ICS_ARCIN_V6_INTROFFSET_2);
}

/* Prototype: icside_irqprobe(struct expansion_card *ec)
 * Purpose  : detect an active interrupt from card
 */
static int icside_irqpending_arcin_v6(struct expansion_card *ec)
{
        struct icside_state *state = ec->irq_data;

        return readb(state->irq_port + ICS_ARCIN_V6_INTRSTAT_1) & 1 ||
               readb(state->irq_port + ICS_ARCIN_V6_INTRSTAT_2) & 1;
}

static const expansioncard_ops_t icside_ops_arcin_v6 = {
        .irqenable      = icside_irqenable_arcin_v6,
        .irqdisable     = icside_irqdisable_arcin_v6,
        .irqpending     = icside_irqpending_arcin_v6,
};

/*
 * Handle routing of interrupts.  This is called before
 * we write the command to the drive.
 */
static void icside_maskproc(ide_drive_t *drive, int mask)
{
        ide_hwif_t *hwif = drive->hwif;
        struct expansion_card *ec = ECARD_DEV(hwif->dev);
        struct icside_state *state = ecard_get_drvdata(ec);
        unsigned long flags;

        local_irq_save(flags);

        state->channel = hwif->channel;

        if (state->enabled && !mask) {
                switch (hwif->channel) {
                case 0:
                        writeb(0, state->irq_port + ICS_ARCIN_V6_INTROFFSET_1);
                        readb(state->irq_port + ICS_ARCIN_V6_INTROFFSET_2);
                        break;
                case 1:
                        writeb(0, state->irq_port + ICS_ARCIN_V6_INTROFFSET_2);
                        readb(state->irq_port + ICS_ARCIN_V6_INTROFFSET_1);
                        break;
                }
        } else {
                readb(state->irq_port + ICS_ARCIN_V6_INTROFFSET_2);
                readb(state->irq_port + ICS_ARCIN_V6_INTROFFSET_1);
        }

        local_irq_restore(flags);
}

static const struct ide_port_ops icside_v6_no_dma_port_ops = {
        .maskproc               = icside_maskproc,
};

#ifdef CONFIG_BLK_DEV_IDEDMA_ICS
/*
 * SG-DMA support.
 *
 * Similar to the BM-DMA, but we use the RiscPCs IOMD DMA controllers.
 * There is only one DMA controller per card, which means that only
 * one drive can be accessed at one time.  NOTE! We do not enforce that
 * here, but we rely on the main IDE driver spotting that both
 * interfaces use the same IRQ, which should guarantee this.
 */

/*
 * Configure the IOMD to give the appropriate timings for the transfer
 * mode being requested.  We take the advice of the ATA standards, and
 * calculate the cycle time based on the transfer mode, and the EIDE
 * MW DMA specs that the drive provides in the IDENTIFY command.
 *
 * We have the following IOMD DMA modes to choose from:
 *
 *      Type    Active          Recovery        Cycle
 *      A       250 (250)       312 (550)       562 (800)
 *      B       187             250             437
 *      C       125 (125)       125 (375)       250 (500)
 *      D       62              125             187
 *
 * (figures in brackets are actual measured timings)
 *
 * However, we also need to take care of the read/write active and
 * recovery timings:
 *
 *                      Read    Write
 *      Mode    Active  -- Recovery --  Cycle   IOMD type
 *      MW0     215     50      215     480     A
 *      MW1     80      50      50      150     C
 *      MW2     70      25      25      120     C
 */
static void icside_set_dma_mode(ide_hwif_t *hwif, ide_drive_t *drive)
{
        unsigned long cycle_time = 0;
        int use_dma_info = 0;
        const u8 xfer_mode = drive->dma_mode;

        switch (xfer_mode) {
        case XFER_MW_DMA_2:
                cycle_time = 250;
                use_dma_info = 1;
                break;

        case XFER_MW_DMA_1:
                cycle_time = 250;
                use_dma_info = 1;
                break;

        case XFER_MW_DMA_0:
                cycle_time = 480;
                break;

        case XFER_SW_DMA_2:
        case XFER_SW_DMA_1:
        case XFER_SW_DMA_0:
                cycle_time = 480;
                break;
        }

        /*
         * If we're going to be doing MW_DMA_1 or MW_DMA_2, we should
         * take care to note the values in the ID...
         */
        if (use_dma_info && drive->id[ATA_ID_EIDE_DMA_TIME] > cycle_time)
                cycle_time = drive->id[ATA_ID_EIDE_DMA_TIME];

        ide_set_drivedata(drive, (void *)cycle_time);

        printk(KERN_INFO "%s: %s selected (peak %luMB/s)\n",
               drive->name, ide_xfer_verbose(xfer_mode),
               2000 / (cycle_time ? cycle_time : (unsigned long) -1));
}

static const struct ide_port_ops icside_v6_port_ops = {
        .set_dma_mode           = icside_set_dma_mode,
        .maskproc               = icside_maskproc,
};

static void icside_dma_host_set(ide_drive_t *drive, int on)
{
}

static int icside_dma_end(ide_drive_t *drive)
{
        ide_hwif_t *hwif = drive->hwif;
        struct expansion_card *ec = ECARD_DEV(hwif->dev);

        disable_dma(ec->dma);

        return get_dma_residue(ec->dma) != 0;
}

static void icside_dma_start(ide_drive_t *drive)
{
        ide_hwif_t *hwif = drive->hwif;
        struct expansion_card *ec = ECARD_DEV(hwif->dev);

        /* We can not enable DMA on both channels simultaneously. */
        BUG_ON(dma_channel_active(ec->dma));
        enable_dma(ec->dma);
}

static int icside_dma_setup(ide_drive_t *drive, struct ide_cmd *cmd)
{
        ide_hwif_t *hwif = drive->hwif;
        struct expansion_card *ec = ECARD_DEV(hwif->dev);
        struct icside_state *state = ecard_get_drvdata(ec);
        unsigned int dma_mode;

        if (cmd->tf_flags & IDE_TFLAG_WRITE)
                dma_mode = DMA_MODE_WRITE;
        else
                dma_mode = DMA_MODE_READ;

        /*
         * We can not enable DMA on both channels.
         */
        BUG_ON(dma_channel_active(ec->dma));

        /*
         * Ensure that we have the right interrupt routed.
         */
        icside_maskproc(drive, 0);

        /*
         * Route the DMA signals to the correct interface.
         */
        writeb(state->sel | hwif->channel, state->ioc_base);

        /*
         * Select the correct timing for this drive.
         */
        set_dma_speed(ec->dma, (unsigned long)ide_get_drivedata(drive));

        /*
         * Tell the DMA engine about the SG table and
         * data direction.
         */
        set_dma_sg(ec->dma, hwif->sg_table, cmd->sg_nents);
        set_dma_mode(ec->dma, dma_mode);

        return 0;
}

static int icside_dma_test_irq(ide_drive_t *drive)
{
        ide_hwif_t *hwif = drive->hwif;
        struct expansion_card *ec = ECARD_DEV(hwif->dev);
        struct icside_state *state = ecard_get_drvdata(ec);

        return readb(state->irq_port +
                     (hwif->channel ?
                        ICS_ARCIN_V6_INTRSTAT_2 :
                        ICS_ARCIN_V6_INTRSTAT_1)) & 1;
}

static int icside_dma_init(ide_hwif_t *hwif, const struct ide_port_info *d)
{
        hwif->dmatable_cpu      = NULL;
        hwif->dmatable_dma      = 0;

        return 0;
}

static const struct ide_dma_ops icside_v6_dma_ops = {
        .dma_host_set           = icside_dma_host_set,
        .dma_setup              = icside_dma_setup,
        .dma_start              = icside_dma_start,
        .dma_end                = icside_dma_end,
        .dma_test_irq           = icside_dma_test_irq,
        .dma_lost_irq           = ide_dma_lost_irq,
};
#endif

static int icside_dma_off_init(ide_hwif_t *hwif, const struct ide_port_info *d)
{
        return -EOPNOTSUPP;
}

static void icside_setup_ports(struct ide_hw *hw, void __iomem *base,
                               struct cardinfo *info, struct expansion_card *ec)
{
        unsigned long port = (unsigned long)base + info->dataoffset;

        hw->io_ports.data_addr   = port;
        hw->io_ports.error_addr  = port + (1 << info->stepping);
        hw->io_ports.nsect_addr  = port + (2 << info->stepping);
        hw->io_ports.lbal_addr   = port + (3 << info->stepping);
        hw->io_ports.lbam_addr   = port + (4 << info->stepping);
        hw->io_ports.lbah_addr   = port + (5 << info->stepping);
        hw->io_ports.device_addr = port + (6 << info->stepping);
        hw->io_ports.status_addr = port + (7 << info->stepping);
        hw->io_ports.ctl_addr    = (unsigned long)base + info->ctrloffset;

        hw->irq = ec->irq;
        hw->dev = &ec->dev;
}

static const struct ide_port_info icside_v5_port_info = {
        .host_flags             = IDE_HFLAG_NO_DMA,
        .chipset                = ide_acorn,
};

static int icside_register_v5(struct icside_state *state,
                              struct expansion_card *ec)
{
        void __iomem *base;
        struct ide_host *host;
        struct ide_hw hw, *hws[] = { &hw };
        int ret;

        base = ecardm_iomap(ec, ECARD_RES_MEMC, 0, 0);
        if (!base)
                return -ENOMEM;

        state->irq_port = base;

        ec->irqaddr  = base + ICS_ARCIN_V5_INTRSTAT;
        ec->irqmask  = 1;

        ecard_setirq(ec, &icside_ops_arcin_v5, state);

        /*
         * Be on the safe side - disable interrupts
         */
        icside_irqdisable_arcin_v5(ec, 0);

        icside_setup_ports(&hw, base, &icside_cardinfo_v5, ec);

        host = ide_host_alloc(&icside_v5_port_info, hws, 1);
        if (host == NULL)
                return -ENODEV;

        state->host = host;

        ecard_set_drvdata(ec, state);

        ret = ide_host_register(host, &icside_v5_port_info, hws);
        if (ret)
                goto err_free;

        return 0;
err_free:
        ide_host_free(host);
        ecard_set_drvdata(ec, NULL);
        return ret;
}

static const struct ide_port_info icside_v6_port_info = {
        .init_dma               = icside_dma_off_init,
        .port_ops               = &icside_v6_no_dma_port_ops,
        .host_flags             = IDE_HFLAG_SERIALIZE | IDE_HFLAG_MMIO,
        .mwdma_mask             = ATA_MWDMA2,
        .swdma_mask             = ATA_SWDMA2,
        .chipset                = ide_acorn,
};

static int icside_register_v6(struct icside_state *state,
                              struct expansion_card *ec)
{
        void __iomem *ioc_base, *easi_base;
        struct ide_host *host;
        unsigned int sel = 0;
        int ret;
        struct ide_hw hw[2], *hws[] = { &hw[0], &hw[1] };
        struct ide_port_info d = icside_v6_port_info;

        ioc_base = ecardm_iomap(ec, ECARD_RES_IOCFAST, 0, 0);
        if (!ioc_base) {
                ret = -ENOMEM;
                goto out;
        }

        easi_base = ioc_base;

        if (ecard_resource_flags(ec, ECARD_RES_EASI)) {
                easi_base = ecardm_iomap(ec, ECARD_RES_EASI, 0, 0);
                if (!easi_base) {
                        ret = -ENOMEM;
                        goto out;
                }

                /*
                 * Enable access to the EASI region.
                 */
                sel = 1 << 5;
        }

        writeb(sel, ioc_base);

        ecard_setirq(ec, &icside_ops_arcin_v6, state);

        state->irq_port   = easi_base;
        state->ioc_base   = ioc_base;
        state->sel        = sel;

        /*
         * Be on the safe side - disable interrupts
         */
        icside_irqdisable_arcin_v6(ec, 0);

        icside_setup_ports(&hw[0], easi_base, &icside_cardinfo_v6_1, ec);
        icside_setup_ports(&hw[1], easi_base, &icside_cardinfo_v6_2, ec);

        host = ide_host_alloc(&d, hws, 2);
        if (host == NULL)
                return -ENODEV;

        state->host = host;

        ecard_set_drvdata(ec, state);

#ifdef CONFIG_BLK_DEV_IDEDMA_ICS
        if (ec->dma != NO_DMA && !request_dma(ec->dma, DRV_NAME)) {
                d.init_dma = icside_dma_init;
                d.port_ops = &icside_v6_port_ops;
                d.dma_ops  = &icside_v6_dma_ops;
        }
#endif

        ret = ide_host_register(host, &d, hws);
        if (ret)
                goto err_free;

        return 0;
err_free:
        ide_host_free(host);
        if (d.dma_ops)
                free_dma(ec->dma);
        ecard_set_drvdata(ec, NULL);
out:
        return ret;
}

static int icside_probe(struct expansion_card *ec, const struct ecard_id *id)
{
        struct icside_state *state;
        void __iomem *idmem;
        int ret;

        ret = ecard_request_resources(ec);
        if (ret)
                goto out;

        state = kzalloc(sizeof(struct icside_state), GFP_KERNEL);
        if (!state) {
                ret = -ENOMEM;
                goto release;
        }

        state->type     = ICS_TYPE_NOTYPE;

        idmem = ecardm_iomap(ec, ECARD_RES_IOCFAST, 0, 0);
        if (idmem) {
                unsigned int type;

                type = readb(idmem + ICS_IDENT_OFFSET) & 1;
                type |= (readb(idmem + ICS_IDENT_OFFSET + 4) & 1) << 1;
                type |= (readb(idmem + ICS_IDENT_OFFSET + 8) & 1) << 2;
                type |= (readb(idmem + ICS_IDENT_OFFSET + 12) & 1) << 3;
                ecardm_iounmap(ec, idmem);

                state->type = type;
        }

        switch (state->type) {
        case ICS_TYPE_A3IN:
                dev_warn(&ec->dev, "A3IN unsupported\n");
                ret = -ENODEV;
                break;

        case ICS_TYPE_A3USER:
                dev_warn(&ec->dev, "A3USER unsupported\n");
                ret = -ENODEV;
                break;

        case ICS_TYPE_V5:
                ret = icside_register_v5(state, ec);
                break;

        case ICS_TYPE_V6:
                ret = icside_register_v6(state, ec);
                break;

        default:
                dev_warn(&ec->dev, "unknown interface type\n");
                ret = -ENODEV;
                break;
        }

        if (ret == 0)
                goto out;

        kfree(state);
 release:
        ecard_release_resources(ec);
 out:
        return ret;
}

static void icside_remove(struct expansion_card *ec)
{
        struct icside_state *state = ecard_get_drvdata(ec);

        switch (state->type) {
        case ICS_TYPE_V5:
                /* FIXME: tell IDE to stop using the interface */

                /* Disable interrupts */
                icside_irqdisable_arcin_v5(ec, 0);
                break;

        case ICS_TYPE_V6:
                /* FIXME: tell IDE to stop using the interface */
                if (ec->dma != NO_DMA)
                        free_dma(ec->dma);

                /* Disable interrupts */
                icside_irqdisable_arcin_v6(ec, 0);

                /* Reset the ROM pointer/EASI selection */
                writeb(0, state->ioc_base);
                break;
        }

        ecard_set_drvdata(ec, NULL);

        kfree(state);
        ecard_release_resources(ec);
}

static void icside_shutdown(struct expansion_card *ec)
{
        struct icside_state *state = ecard_get_drvdata(ec);
        unsigned long flags;

        /*
         * Disable interrupts from this card.  We need to do
         * this before disabling EASI since we may be accessing
         * this register via that region.
         */
        local_irq_save(flags);
        ec->ops->irqdisable(ec, 0);
        local_irq_restore(flags);

        /*
         * Reset the ROM pointer so that we can read the ROM
         * after a soft reboot.  This also disables access to
         * the IDE taskfile via the EASI region.
         */
        if (state->ioc_base)
                writeb(0, state->ioc_base);
}

static const struct ecard_id icside_ids[] = {
        { MANU_ICS,  PROD_ICS_IDE  },
        { MANU_ICS2, PROD_ICS2_IDE },
        { 0xffff, 0xffff }
};

static struct ecard_driver icside_driver = {
        .probe          = icside_probe,
        .remove         = icside_remove,
        .shutdown       = icside_shutdown,
        .id_table       = icside_ids,
        .drv = {
                .name   = "icside",
        },
};

static int __init icside_init(void)
{
        return ecard_register_driver(&icside_driver);
}

static void __exit icside_exit(void)
{
        ecard_remove_driver(&icside_driver);
}

MODULE_AUTHOR("Russell King <rmk@arm.linux.org.uk>");
MODULE_LICENSE("GPL");
MODULE_DESCRIPTION("ICS IDE driver");

module_init(icside_init);
module_exit(icside_exit);