// 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/ide.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 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
  ");
  	}
  	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
  ", 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);