// SPDX-License-Identifier: GPL-2.0
#include <linux/types.h>
#include <linux/mm.h>
#include <linux/blkdev.h>
#include <linux/interrupt.h>
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/module.h>

#include <asm/page.h>
#include <asm/mvme147hw.h>
#include <asm/irq.h>

#include <scsi/scsi.h>
#include <scsi/scsi_cmnd.h>
#include <scsi/scsi_device.h>
#include <scsi/scsi_eh.h>
#include <scsi/scsi_host.h>
#include <scsi/scsi_tcq.h>
#include "wd33c93.h"
#include "mvme147.h"

static irqreturn_t mvme147_intr(int irq, void *data)
{
        struct Scsi_Host *instance = data;

        if (irq == MVME147_IRQ_SCSI_PORT)
                wd33c93_intr(instance);
        else
                m147_pcc->dma_intr = 0x89;      /* Ack and enable ints */
        return IRQ_HANDLED;
}

static int dma_setup(struct scsi_cmnd *cmd, int dir_in)
{
        struct scsi_pointer *scsi_pointer = WD33C93_scsi_pointer(cmd);
        struct Scsi_Host *instance = cmd->device->host;
        struct WD33C93_hostdata *hdata = shost_priv(instance);
        unsigned char flags = 0x01;
        unsigned long addr = virt_to_bus(scsi_pointer->ptr);

        /* setup dma direction */
        if (!dir_in)
                flags |= 0x04;

        /* remember direction */
        hdata->dma_dir = dir_in;

        if (dir_in) {
                /* invalidate any cache */
                cache_clear(addr, scsi_pointer->this_residual);
        } else {
                /* push any dirty cache */
                cache_push(addr, scsi_pointer->this_residual);
        }

        /* start DMA */
        m147_pcc->dma_bcr = scsi_pointer->this_residual | (1 << 24);
        m147_pcc->dma_dadr = addr;
        m147_pcc->dma_cntrl = flags;

        /* return success */
        return 0;
}

static void dma_stop(struct Scsi_Host *instance, struct scsi_cmnd *SCpnt,
                     int status)
{
        m147_pcc->dma_cntrl = 0;
}

static const struct scsi_host_template mvme147_host_template = {
        .module                 = THIS_MODULE,
        .proc_name              = "MVME147",
        .name                   = "MVME147 built-in SCSI",
        .queuecommand           = wd33c93_queuecommand,
        .eh_abort_handler       = wd33c93_abort,
        .eh_host_reset_handler  = wd33c93_host_reset,
        .show_info              = wd33c93_show_info,
        .write_info             = wd33c93_write_info,
        .can_queue              = CAN_QUEUE,
        .this_id                = 7,
        .sg_tablesize           = SG_ALL,
        .cmd_per_lun            = CMD_PER_LUN,
        .cmd_size               = sizeof(struct scsi_pointer),
};

static struct Scsi_Host *mvme147_shost;

static int __init mvme147_init(void)
{
        wd33c93_regs regs;
        struct WD33C93_hostdata *hdata;
        int error = -ENOMEM;

        if (!MACH_IS_MVME147)
                return 0;

        mvme147_shost = scsi_host_alloc(&mvme147_host_template,
                        sizeof(struct WD33C93_hostdata));
        if (!mvme147_shost)
                goto err_out;
        mvme147_shost->base = 0xfffe4000;
        mvme147_shost->irq = MVME147_IRQ_SCSI_PORT;

        regs.SASR = (volatile unsigned char *)0xfffe4000;
        regs.SCMD = (volatile unsigned char *)0xfffe4001;

        hdata = shost_priv(mvme147_shost);
        hdata->no_sync = 0xff;
        hdata->fast = 0;
        hdata->dma_mode = CTRL_DMA;

        wd33c93_init(mvme147_shost, regs, dma_setup, dma_stop, WD33C93_FS_8_10);

        error = request_irq(MVME147_IRQ_SCSI_PORT, mvme147_intr, 0,
                        "MVME147 SCSI PORT", mvme147_shost);
        if (error)
                goto err_unregister;
        error = request_irq(MVME147_IRQ_SCSI_DMA, mvme147_intr, 0,
                        "MVME147 SCSI DMA", mvme147_shost);
        if (error)
                goto err_free_irq;
#if 0   /* Disabled; causes problems booting */
        m147_pcc->scsi_interrupt = 0x10;        /* Assert SCSI bus reset */
        udelay(100);
        m147_pcc->scsi_interrupt = 0x00;        /* Negate SCSI bus reset */
        udelay(2000);
        m147_pcc->scsi_interrupt = 0x40;        /* Clear bus reset interrupt */
#endif
        m147_pcc->scsi_interrupt = 0x09;        /* Enable interrupt */

        m147_pcc->dma_cntrl = 0x00;     /* ensure DMA is stopped */
        m147_pcc->dma_intr = 0x89;      /* Ack and enable ints */

        error = scsi_add_host(mvme147_shost, NULL);
        if (error)
                goto err_free_irq;
        scsi_scan_host(mvme147_shost);
        return 0;

err_free_irq:
        free_irq(MVME147_IRQ_SCSI_PORT, mvme147_shost);
err_unregister:
        scsi_host_put(mvme147_shost);
err_out:
        return error;
}

static void __exit mvme147_exit(void)
{
        scsi_remove_host(mvme147_shost);

        /* XXX Make sure DMA is stopped! */
        free_irq(MVME147_IRQ_SCSI_PORT, mvme147_shost);
        free_irq(MVME147_IRQ_SCSI_DMA, mvme147_shost);

        scsi_host_put(mvme147_shost);
}

module_init(mvme147_init);
module_exit(mvme147_exit);