// SPDX-License-Identifier: GPL-2.0-only

  #include <linux/types.h>
  #include <linux/mm.h>

  #include <linux/ioport.h>
  #include <linux/init.h>

  #include <linux/slab.h>

  #include <linux/spinlock.h>
  #include <linux/interrupt.h>

  #include <linux/platform_device.h>

  #include <linux/module.h>

  #include <asm/page.h>
  #include <asm/pgtable.h>
  #include <asm/amigaints.h>
  #include <asm/amigahw.h>

  
  #include "scsi.h"

  #include "wd33c93.h"
  #include "a3000.h"

  struct a3000_hostdata {
  	struct WD33C93_hostdata wh;
  	struct a3000_scsiregs *regs;
  };

  static irqreturn_t a3000_intr(int irq, void *data)

  {

  	struct Scsi_Host *instance = data;

  	struct a3000_hostdata *hdata = shost_priv(instance);
  	unsigned int status = hdata->regs->ISTR;

  	unsigned long flags;

  
  	if (!(status & ISTR_INT_P))
  		return IRQ_NONE;

  	if (status & ISTR_INTS) {

  		spin_lock_irqsave(instance->host_lock, flags);
  		wd33c93_intr(instance);
  		spin_unlock_irqrestore(instance->host_lock, flags);

  		return IRQ_HANDLED;
  	}

  	pr_warning("Non-serviced A3000 SCSI-interrupt? ISTR = %02x
  ", status);

  	return IRQ_NONE;
  }

  static int dma_setup(struct scsi_cmnd *cmd, int dir_in)

  {

  	struct Scsi_Host *instance = cmd->device->host;

  	struct a3000_hostdata *hdata = shost_priv(instance);
  	struct WD33C93_hostdata *wh = &hdata->wh;
  	struct a3000_scsiregs *regs = hdata->regs;

  	unsigned short cntr = CNTR_PDMD | CNTR_INTEN;
  	unsigned long addr = virt_to_bus(cmd->SCp.ptr);
  
  	/*
  	 * if the physical address has the wrong alignment, or if
  	 * physical address is bad, or if it is a write and at the
  	 * end of a physical memory chunk, then allocate a bounce
  	 * buffer
  	 */
  	if (addr & A3000_XFER_MASK) {

  		wh->dma_bounce_len = (cmd->SCp.this_residual + 511) & ~0x1ff;
  		wh->dma_bounce_buffer = kmalloc(wh->dma_bounce_len,
  						GFP_KERNEL);

  
  		/* can't allocate memory; use PIO */

  		if (!wh->dma_bounce_buffer) {
  			wh->dma_bounce_len = 0;

  			return 1;
  		}
  
  		if (!dir_in) {
  			/* copy to bounce buffer for a write */

  			memcpy(wh->dma_bounce_buffer, cmd->SCp.ptr,

  			       cmd->SCp.this_residual);

  		}

  		addr = virt_to_bus(wh->dma_bounce_buffer);

  	}

  	/* setup dma direction */
  	if (!dir_in)
  		cntr |= CNTR_DDIR;

  	/* remember direction */

  	wh->dma_dir = dir_in;

  	regs->CNTR = cntr;

  	/* setup DMA *physical* address */

  	regs->ACR = addr;

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

  	/* start DMA */
  	mb();			/* make sure setup is completed */

  	regs->ST_DMA = 1;

  	mb();			/* make sure DMA has started before next IO */

  	/* return success */
  	return 0;

  }

  static void dma_stop(struct Scsi_Host *instance, struct scsi_cmnd *SCpnt,
  		     int status)

  {

  	struct a3000_hostdata *hdata = shost_priv(instance);
  	struct WD33C93_hostdata *wh = &hdata->wh;
  	struct a3000_scsiregs *regs = hdata->regs;

  	/* disable SCSI interrupts */
  	unsigned short cntr = CNTR_PDMD;

  	if (!wh->dma_dir)

  		cntr |= CNTR_DDIR;

  	regs->CNTR = cntr;

  	mb();			/* make sure CNTR is updated before next IO */
  
  	/* flush if we were reading */

  	if (wh->dma_dir) {

  		regs->FLUSH = 1;

  		mb();		/* don't allow prefetch */

  		while (!(regs->ISTR & ISTR_FE_FLG))

  			barrier();
  		mb();		/* no IO until FLUSH is done */
  	}
  
  	/* clear a possible interrupt */
  	/* I think that this CINT is only necessary if you are
  	 * using the terminal count features.   HM 7 Mar 1994
  	 */

  	regs->CINT = 1;

  
  	/* stop DMA */

  	regs->SP_DMA = 1;

  	mb();			/* make sure DMA is stopped before next IO */
  
  	/* restore the CONTROL bits (minus the direction flag) */

  	regs->CNTR = CNTR_PDMD | CNTR_INTEN;

  	mb();			/* make sure CNTR is updated before next IO */
  
  	/* copy from a bounce buffer, if necessary */

  	if (status && wh->dma_bounce_buffer) {

  		if (SCpnt) {

  			if (wh->dma_dir && SCpnt)
  				memcpy(SCpnt->SCp.ptr, wh->dma_bounce_buffer,

  				       SCpnt->SCp.this_residual);

  			kfree(wh->dma_bounce_buffer);
  			wh->dma_bounce_buffer = NULL;
  			wh->dma_bounce_len = 0;

  		} else {

  			kfree(wh->dma_bounce_buffer);
  			wh->dma_bounce_buffer = NULL;
  			wh->dma_bounce_len = 0;

  		}

  	}

  }

  static struct scsi_host_template amiga_a3000_scsi_template = {
  	.module			= THIS_MODULE,
  	.name			= "Amiga 3000 built-in SCSI",

  	.show_info		= wd33c93_show_info,
  	.write_info		= wd33c93_write_info,

  	.proc_name		= "A3000",
  	.queuecommand		= wd33c93_queuecommand,
  	.eh_abort_handler	= wd33c93_abort,

  	.eh_host_reset_handler	= wd33c93_host_reset,
  	.can_queue		= CAN_QUEUE,
  	.this_id		= 7,
  	.sg_tablesize		= SG_ALL,
  	.cmd_per_lun		= CMD_PER_LUN,

  };
  
  static int __init amiga_a3000_scsi_probe(struct platform_device *pdev)

  {

  	struct resource *res;

  	struct Scsi_Host *instance;

  	int error;

  	struct a3000_scsiregs *regs;

  	wd33c93_regs wdregs;

  	struct a3000_hostdata *hdata;

  	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
  	if (!res)
  		return -ENODEV;

  	if (!request_mem_region(res->start, resource_size(res), "wd33c93"))
  		return -EBUSY;

  	instance = scsi_host_alloc(&amiga_a3000_scsi_template,

  				   sizeof(struct a3000_hostdata));

  	if (!instance) {
  		error = -ENOMEM;
  		goto fail_alloc;
  	}

  	instance->irq = IRQ_AMIGA_PORTS;

  	regs = ZTWO_VADDR(res->start);

  	regs->DAWR = DAWR_A3000;

  	wdregs.SASR = &regs->SASR;
  	wdregs.SCMD = &regs->SCMD;

  	hdata = shost_priv(instance);

  	hdata->wh.no_sync = 0xff;
  	hdata->wh.fast = 0;
  	hdata->wh.dma_mode = CTRL_DMA;
  	hdata->regs = regs;

  	wd33c93_init(instance, wdregs, dma_setup, dma_stop, WD33C93_FS_12_15);

  	error = request_irq(IRQ_AMIGA_PORTS, a3000_intr, IRQF_SHARED,
  			    "A3000 SCSI", instance);
  	if (error)

  		goto fail_irq;

  	regs->CNTR = CNTR_PDMD | CNTR_INTEN;

  	error = scsi_add_host(instance, NULL);
  	if (error)
  		goto fail_host;

  	platform_set_drvdata(pdev, instance);
  
  	scsi_scan_host(instance);

  	return 0;

  
  fail_host:
  	free_irq(IRQ_AMIGA_PORTS, instance);
  fail_irq:
  	scsi_host_put(instance);
  fail_alloc:
  	release_mem_region(res->start, resource_size(res));
  	return error;

  }

  static int __exit amiga_a3000_scsi_remove(struct platform_device *pdev)

  {

  	struct Scsi_Host *instance = platform_get_drvdata(pdev);

  	struct a3000_hostdata *hdata = shost_priv(instance);

  	struct resource *res = platform_get_resource(pdev, IORESOURCE_MEM, 0);

  	hdata->regs->CNTR = 0;

  	scsi_remove_host(instance);
  	free_irq(IRQ_AMIGA_PORTS, instance);
  	scsi_host_put(instance);
  	release_mem_region(res->start, resource_size(res));
  	return 0;

  }

  static struct platform_driver amiga_a3000_scsi_driver = {
  	.remove = __exit_p(amiga_a3000_scsi_remove),
  	.driver   = {
  		.name	= "amiga-a3000-scsi",

  	},

  };

  module_platform_driver_probe(amiga_a3000_scsi_driver, amiga_a3000_scsi_probe);

  MODULE_DESCRIPTION("Amiga 3000 built-in SCSI");

  MODULE_LICENSE("GPL");

  MODULE_ALIAS("platform:amiga-a3000-scsi");