// SPDX-License-Identifier: GPL-2.0

  /*
   * Atari Falcon PATA controller driver
   *
   * Copyright (c) 2016 Samsung Electronics Co., Ltd.
   *		http://www.samsung.com
   *
   * Based on falconide.c:
   *
   *     Created 12 Jul 1997 by Geert Uytterhoeven

   */
  
  #include <linux/kernel.h>
  #include <linux/module.h>
  #include <linux/init.h>
  #include <linux/blkdev.h>
  #include <linux/delay.h>
  #include <scsi/scsi_host.h>
  #include <scsi/scsi_cmnd.h>
  #include <linux/ata.h>
  #include <linux/libata.h>
  #include <linux/mm.h>
  #include <linux/interrupt.h>
  #include <linux/platform_device.h>
  
  #include <asm/setup.h>
  #include <asm/atarihw.h>
  #include <asm/atariints.h>
  #include <asm/atari_stdma.h>
  #include <asm/ide.h>
  
  #define DRV_NAME "pata_falcon"
  #define DRV_VERSION "0.1.0"

  #define ATA_HD_CONTROL	0x39
  
  static struct scsi_host_template pata_falcon_sht = {
  	ATA_PIO_SHT(DRV_NAME),
  };
  
  static unsigned int pata_falcon_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;
  	struct scsi_cmnd *cmd = qc->scsicmd;
  	bool swap = 1;
  
  	if (dev->class == ATA_DEV_ATA && cmd && cmd->request &&

  	    !blk_rq_is_passthrough(cmd->request))

  		swap = 0;
  
  	/* Transfer multiple of 2 bytes */
  	if (rw == READ) {
  		if (swap)
  			raw_insw_swapw((u16 *)data_addr, (u16 *)buf, words);
  		else
  			raw_insw((u16 *)data_addr, (u16 *)buf, words);
  	} else {
  		if (swap)
  			raw_outsw_swapw((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) {
  			if (swap)
  				raw_insw_swapw((u16 *)data_addr, (u16 *)pad, 1);
  			else
  				raw_insw((u16 *)data_addr, (u16 *)pad, 1);
  			*buf = pad[0];
  		} else {
  			pad[0] = *buf;
  			if (swap)
  				raw_outsw_swapw((u16 *)data_addr, (u16 *)pad, 1);
  			else
  				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_falcon_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
  ");
  	}
  	return 0;
  }
  
  static struct ata_port_operations pata_falcon_ops = {
  	.inherits	= &ata_sff_port_ops,
  	.sff_data_xfer	= pata_falcon_data_xfer,
  	.cable_detect	= ata_cable_unknown,
  	.set_mode	= pata_falcon_set_mode,
  };

  static int __init pata_falcon_init_one(struct platform_device *pdev)

  {

  	struct resource *res;

  	struct ata_host *host;
  	struct ata_port *ap;

  	void __iomem *base;

  	dev_info(&pdev->dev, "Atari Falcon PATA controller
  ");

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

  	if (!devm_request_mem_region(&pdev->dev, res->start,
  				     resource_size(res), DRV_NAME)) {
  		dev_err(&pdev->dev, "resources busy
  ");

  		return -EBUSY;
  	}
  
  	/* allocate host */
  	host = ata_host_alloc(&pdev->dev, 1);
  	if (!host)
  		return -ENOMEM;
  	ap = host->ports[0];
  
  	ap->ops = &pata_falcon_ops;
  	ap->pio_mask = ATA_PIO4;
  	ap->flags |= ATA_FLAG_SLAVE_POSS | ATA_FLAG_NO_IORDY;
  	ap->flags |= ATA_FLAG_PIO_POLLING;

  	base = (void __iomem *)res->start;

  	ap->ioaddr.data_addr		= base;
  	ap->ioaddr.error_addr		= base + 1 + 1 * 4;
  	ap->ioaddr.feature_addr		= base + 1 + 1 * 4;
  	ap->ioaddr.nsect_addr		= base + 1 + 2 * 4;
  	ap->ioaddr.lbal_addr		= base + 1 + 3 * 4;
  	ap->ioaddr.lbam_addr		= base + 1 + 4 * 4;
  	ap->ioaddr.lbah_addr		= base + 1 + 5 * 4;
  	ap->ioaddr.device_addr		= base + 1 + 6 * 4;
  	ap->ioaddr.status_addr		= base + 1 + 7 * 4;
  	ap->ioaddr.command_addr		= base + 1 + 7 * 4;
  
  	ap->ioaddr.altstatus_addr	= base + ATA_HD_CONTROL;
  	ap->ioaddr.ctl_addr		= base + ATA_HD_CONTROL;
  
  	ata_port_desc(ap, "cmd 0x%lx ctl 0x%lx", (unsigned long)base,
  		      (unsigned long)base + ATA_HD_CONTROL);
  
  	/* activate */
  	return ata_host_activate(host, 0, NULL, 0, &pata_falcon_sht);
  }

  static int __exit pata_falcon_remove_one(struct platform_device *pdev)
  {
  	struct ata_host *host = platform_get_drvdata(pdev);
  
  	ata_host_detach(host);
  
  	return 0;
  }
  
  static struct platform_driver pata_falcon_driver = {
  	.remove = __exit_p(pata_falcon_remove_one),
  	.driver   = {
  		.name	= "atari-falcon-ide",
  	},
  };
  
  module_platform_driver_probe(pata_falcon_driver, pata_falcon_init_one);

  
  MODULE_AUTHOR("Bartlomiej Zolnierkiewicz");
  MODULE_DESCRIPTION("low-level driver for Atari Falcon PATA");

  MODULE_LICENSE("GPL v2");

  MODULE_ALIAS("platform:atari-falcon-ide");

  MODULE_VERSION(DRV_VERSION);