// SPDX-License-Identifier: GPL-2.0

/*
 * Buddha, Catweasel and X-Surf PATA controller driver
 *
 * Copyright (c) 2018 Samsung Electronics Co., Ltd.
 *              http://www.samsung.com
 *
 * Based on buddha.c:
 *
 *      Copyright (C) 1997, 2001 by Geert Uytterhoeven and others
 */

#include <linux/ata.h>
#include <linux/blkdev.h>
#include <linux/delay.h>
#include <linux/interrupt.h>
#include <linux/kernel.h>
#include <linux/libata.h>
#include <linux/mm.h>
#include <linux/mod_devicetable.h>
#include <linux/module.h>
#include <linux/types.h>
#include <linux/zorro.h>
#include <scsi/scsi_cmnd.h>
#include <scsi/scsi_host.h>

#include <asm/amigahw.h>
#include <asm/amigaints.h>
#include <asm/setup.h>

#define DRV_NAME "pata_buddha"
#define DRV_VERSION "0.1.1"

#define BUDDHA_BASE1    0x800
#define BUDDHA_BASE2    0xa00
#define BUDDHA_BASE3    0xc00
#define XSURF_BASE1     0xb000 /* 2.5" interface */
#define XSURF_BASE2     0xd000 /* 3.5" interface */
#define BUDDHA_CONTROL  0x11a
#define BUDDHA_IRQ      0xf00
#define XSURF_IRQ       0x7e
#define BUDDHA_IRQ_MR   0xfc0   /* master interrupt enable */

enum {
        BOARD_BUDDHA = 0,
        BOARD_CATWEASEL,
        BOARD_XSURF
};

static unsigned int buddha_bases[3] = {
        BUDDHA_BASE1, BUDDHA_BASE2, BUDDHA_BASE3
};

static unsigned int xsurf_bases[2] = {
        XSURF_BASE1, XSURF_BASE2
};

static const struct scsi_host_template pata_buddha_sht = {
        ATA_PIO_SHT(DRV_NAME),
};

/* FIXME: is this needed? */
static unsigned int pata_buddha_data_xfer(struct ata_queued_cmd *qc,
                                         unsigned char *buf,
                                         unsigned int buflen, int rw)
{
        struct ata_device *dev = qc->dev;
        struct ata_port *ap = dev->link->ap;
        void __iomem *data_addr = ap->ioaddr.data_addr;
        unsigned int words = buflen >> 1;

        /* Transfer multiple of 2 bytes */
        if (rw == READ)
                raw_insw((u16 *)data_addr, (u16 *)buf, words);
        else
                raw_outsw((u16 *)data_addr, (u16 *)buf, words);

        /* Transfer trailing byte, if any. */
        if (unlikely(buflen & 0x01)) {
                unsigned char pad[2] = { };

                /* Point buf to the tail of buffer */
                buf += buflen - 1;

                if (rw == READ) {
                        raw_insw((u16 *)data_addr, (u16 *)pad, 1);
                        *buf = pad[0];
                } else {
                        pad[0] = *buf;
                        raw_outsw((u16 *)data_addr, (u16 *)pad, 1);
                }
                words++;
        }

        return words << 1;
}

/*
 * Provide our own set_mode() as we don't want to change anything that has
 * already been configured..
 */
static int pata_buddha_set_mode(struct ata_link *link,
                                struct ata_device **unused)
{
        struct ata_device *dev;

        ata_for_each_dev(dev, link, ENABLED) {
                /* We don't really care */
                dev->pio_mode = dev->xfer_mode = XFER_PIO_0;
                dev->xfer_shift = ATA_SHIFT_PIO;
                dev->flags |= ATA_DFLAG_PIO;
                ata_dev_info(dev, "configured for PIO\n");
        }
        return 0;
}

static bool pata_buddha_irq_check(struct ata_port *ap)
{
        u8 ch;

        ch = z_readb((unsigned long)ap->private_data);

        return !!(ch & 0x80);
}

static void pata_xsurf_irq_clear(struct ata_port *ap)
{
        z_writeb(0, (unsigned long)ap->private_data);
}

static struct ata_port_operations pata_buddha_ops = {
        .inherits       = &ata_sff_port_ops,
        .sff_data_xfer  = pata_buddha_data_xfer,
        .sff_irq_check  = pata_buddha_irq_check,
        .cable_detect   = ata_cable_unknown,
        .set_mode       = pata_buddha_set_mode,
};

static struct ata_port_operations pata_xsurf_ops = {
        .inherits       = &ata_sff_port_ops,
        .sff_data_xfer  = pata_buddha_data_xfer,
        .sff_irq_check  = pata_buddha_irq_check,
        .sff_irq_clear  = pata_xsurf_irq_clear,
        .cable_detect   = ata_cable_unknown,
        .set_mode       = pata_buddha_set_mode,
};

static int pata_buddha_probe(struct zorro_dev *z,
                             const struct zorro_device_id *ent)
{
        static const char * const board_name[] = {
                "Buddha", "Catweasel", "X-Surf"
        };
        struct ata_host *host;
        void __iomem *buddha_board;
        unsigned long board;
        unsigned int type = ent->driver_data;
        unsigned int nr_ports = (type == BOARD_CATWEASEL) ? 3 : 2;
        void *old_drvdata;
        int i;

        dev_info(&z->dev, "%s IDE controller\n", board_name[type]);

        board = z->resource.start;

        if (type != BOARD_XSURF) {
                if (!devm_request_mem_region(&z->dev,
                                             board + BUDDHA_BASE1,
                                             0x800, DRV_NAME))
                        return -ENXIO;
        } else {
                if (!devm_request_mem_region(&z->dev,
                                             board + XSURF_BASE1,
                                             0x1000, DRV_NAME))
                        return -ENXIO;
                if (!devm_request_mem_region(&z->dev,
                                             board + XSURF_BASE2,
                                             0x1000, DRV_NAME)) {
                }
        }

        /* Workaround for X-Surf: Save drvdata in case zorro8390 has set it */
        if (type == BOARD_XSURF)
                old_drvdata = dev_get_drvdata(&z->dev);

        /* allocate host */
        host = ata_host_alloc(&z->dev, nr_ports);
        if (type == BOARD_XSURF)
                dev_set_drvdata(&z->dev, old_drvdata);
        if (!host)
                return -ENXIO;

        buddha_board = ZTWO_VADDR(board);

        /* enable the board IRQ on Buddha/Catweasel */
        if (type != BOARD_XSURF)
                z_writeb(0, buddha_board + BUDDHA_IRQ_MR);

        for (i = 0; i < nr_ports; i++) {
                struct ata_port *ap = host->ports[i];
                void __iomem *base, *irqport;
                unsigned long ctl = 0;

                if (type != BOARD_XSURF) {
                        ap->ops = &pata_buddha_ops;
                        base = buddha_board + buddha_bases[i];
                        ctl = BUDDHA_CONTROL;
                        irqport = buddha_board + BUDDHA_IRQ + i * 0x40;
                } else {
                        ap->ops = &pata_xsurf_ops;
                        base = buddha_board + xsurf_bases[i];
                        /* X-Surf has no CS1* (Control/AltStat) */
                        irqport = buddha_board + XSURF_IRQ;
                }

                ap->pio_mask = ATA_PIO4;
                ap->flags |= ATA_FLAG_SLAVE_POSS | ATA_FLAG_NO_IORDY;

                ap->ioaddr.data_addr            = base;
                ap->ioaddr.error_addr           = base + 2 + 1 * 4;
                ap->ioaddr.feature_addr         = base + 2 + 1 * 4;
                ap->ioaddr.nsect_addr           = base + 2 + 2 * 4;
                ap->ioaddr.lbal_addr            = base + 2 + 3 * 4;
                ap->ioaddr.lbam_addr            = base + 2 + 4 * 4;
                ap->ioaddr.lbah_addr            = base + 2 + 5 * 4;
                ap->ioaddr.device_addr          = base + 2 + 6 * 4;
                ap->ioaddr.status_addr          = base + 2 + 7 * 4;
                ap->ioaddr.command_addr         = base + 2 + 7 * 4;

                if (ctl) {
                        ap->ioaddr.altstatus_addr = base + ctl;
                        ap->ioaddr.ctl_addr       = base + ctl;
                }

                ap->private_data = (void *)irqport;

                ata_port_desc(ap, "cmd 0x%lx ctl 0x%lx", board,
                              ctl ? board + buddha_bases[i] + ctl : 0);
        }

        ata_host_activate(host, IRQ_AMIGA_PORTS, ata_sff_interrupt,
                          IRQF_SHARED, &pata_buddha_sht);

        return 0;
}

static void pata_buddha_remove(struct zorro_dev *z)
{
        struct ata_host *host = dev_get_drvdata(&z->dev);

        ata_host_detach(host);
}

static const struct zorro_device_id pata_buddha_zorro_tbl[] = {
        { ZORRO_PROD_INDIVIDUAL_COMPUTERS_BUDDHA, BOARD_BUDDHA},
        { ZORRO_PROD_INDIVIDUAL_COMPUTERS_CATWEASEL, BOARD_CATWEASEL},
        { 0 }
};
MODULE_DEVICE_TABLE(zorro, pata_buddha_zorro_tbl);

static struct zorro_driver pata_buddha_driver = {
        .name           = "pata_buddha",
        .id_table       = pata_buddha_zorro_tbl,
        .probe          = pata_buddha_probe,
        .remove         = pata_buddha_remove,
};

/*
 * We cannot have a modalias for X-Surf boards, as it competes with the
 * zorro8390 network driver. As a stopgap measure until we have proper
 * MFD support for this board, we manually attach to it late after Zorro
 * has enumerated its boards.
 */
static int __init pata_buddha_late_init(void)
{
        struct zorro_dev *z = NULL;

        /* Auto-bind to regular boards */
        zorro_register_driver(&pata_buddha_driver);

        /* Manually bind to all X-Surf boards */
        while ((z = zorro_find_device(ZORRO_PROD_INDIVIDUAL_COMPUTERS_X_SURF, z))) {
                static struct zorro_device_id xsurf_ent = {
                        ZORRO_PROD_INDIVIDUAL_COMPUTERS_X_SURF, BOARD_XSURF
                };

                pata_buddha_probe(z, &xsurf_ent);
        }

        return 0;
}
late_initcall(pata_buddha_late_init);

MODULE_AUTHOR("Bartlomiej Zolnierkiewicz");
MODULE_DESCRIPTION("low-level driver for Buddha/Catweasel/X-Surf PATA");
MODULE_LICENSE("GPL v2");
MODULE_VERSION(DRV_VERSION);