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

  #include <linux/kernel.h>
  #include <linux/module.h>
  #include <linux/init.h>
  #include <linux/blkdev.h>

  #include <linux/gfp.h>

  #include <scsi/scsi_host.h>
  #include <linux/ata.h>
  #include <linux/libata.h>
  
  #include <asm/dma.h>
  #include <asm/ecard.h>
  
  #define DRV_NAME	"pata_icside"
  
  #define ICS_IDENT_OFFSET		0x2280
  
  #define ICS_ARCIN_V5_INTRSTAT		0x0000
  #define ICS_ARCIN_V5_INTROFFSET		0x0004
  
  #define ICS_ARCIN_V6_INTROFFSET_1	0x2200
  #define ICS_ARCIN_V6_INTRSTAT_1		0x2290
  #define ICS_ARCIN_V6_INTROFFSET_2	0x3200
  #define ICS_ARCIN_V6_INTRSTAT_2		0x3290
  
  struct portinfo {
  	unsigned int dataoffset;
  	unsigned int ctrloffset;
  	unsigned int stepping;
  };
  
  static const struct portinfo pata_icside_portinfo_v5 = {
  	.dataoffset	= 0x2800,
  	.ctrloffset	= 0x2b80,
  	.stepping	= 6,
  };
  
  static const struct portinfo pata_icside_portinfo_v6_1 = {
  	.dataoffset	= 0x2000,
  	.ctrloffset	= 0x2380,
  	.stepping	= 6,
  };
  
  static const struct portinfo pata_icside_portinfo_v6_2 = {
  	.dataoffset	= 0x3000,
  	.ctrloffset	= 0x3380,
  	.stepping	= 6,
  };

  struct pata_icside_state {
  	void __iomem *irq_port;
  	void __iomem *ioc_base;
  	unsigned int type;
  	unsigned int dma;
  	struct {
  		u8 port_sel;
  		u8 disabled;
  		unsigned int speed[ATA_MAX_DEVICES];
  	} port[2];

  };

  struct pata_icside_info {
  	struct pata_icside_state *state;
  	struct expansion_card	*ec;
  	void __iomem		*base;
  	void __iomem		*irqaddr;
  	unsigned int		irqmask;
  	const expansioncard_ops_t *irqops;
  	unsigned int		mwdma_mask;
  	unsigned int		nr_ports;
  	const struct portinfo	*port[2];

  	unsigned long		raw_base;
  	unsigned long		raw_ioc_base;

  };

  #define ICS_TYPE_A3IN	0
  #define ICS_TYPE_A3USER	1
  #define ICS_TYPE_V6	3
  #define ICS_TYPE_V5	15
  #define ICS_TYPE_NOTYPE	((unsigned int)-1)
  
  /* ---------------- Version 5 PCB Support Functions --------------------- */
  /* Prototype: pata_icside_irqenable_arcin_v5 (struct expansion_card *ec, int irqnr)
   * Purpose  : enable interrupts from card
   */
  static void pata_icside_irqenable_arcin_v5 (struct expansion_card *ec, int irqnr)
  {
  	struct pata_icside_state *state = ec->irq_data;
  
  	writeb(0, state->irq_port + ICS_ARCIN_V5_INTROFFSET);
  }
  
  /* Prototype: pata_icside_irqdisable_arcin_v5 (struct expansion_card *ec, int irqnr)
   * Purpose  : disable interrupts from card
   */
  static void pata_icside_irqdisable_arcin_v5 (struct expansion_card *ec, int irqnr)
  {
  	struct pata_icside_state *state = ec->irq_data;
  
  	readb(state->irq_port + ICS_ARCIN_V5_INTROFFSET);
  }
  
  static const expansioncard_ops_t pata_icside_ops_arcin_v5 = {
  	.irqenable	= pata_icside_irqenable_arcin_v5,
  	.irqdisable	= pata_icside_irqdisable_arcin_v5,
  };
  
  
  /* ---------------- Version 6 PCB Support Functions --------------------- */
  /* Prototype: pata_icside_irqenable_arcin_v6 (struct expansion_card *ec, int irqnr)
   * Purpose  : enable interrupts from card
   */
  static void pata_icside_irqenable_arcin_v6 (struct expansion_card *ec, int irqnr)
  {
  	struct pata_icside_state *state = ec->irq_data;
  	void __iomem *base = state->irq_port;
  
  	if (!state->port[0].disabled)
  		writeb(0, base + ICS_ARCIN_V6_INTROFFSET_1);
  	if (!state->port[1].disabled)
  		writeb(0, base + ICS_ARCIN_V6_INTROFFSET_2);
  }
  
  /* Prototype: pata_icside_irqdisable_arcin_v6 (struct expansion_card *ec, int irqnr)
   * Purpose  : disable interrupts from card
   */
  static void pata_icside_irqdisable_arcin_v6 (struct expansion_card *ec, int irqnr)
  {
  	struct pata_icside_state *state = ec->irq_data;
  
  	readb(state->irq_port + ICS_ARCIN_V6_INTROFFSET_1);
  	readb(state->irq_port + ICS_ARCIN_V6_INTROFFSET_2);
  }
  
  /* Prototype: pata_icside_irqprobe(struct expansion_card *ec)
   * Purpose  : detect an active interrupt from card
   */
  static int pata_icside_irqpending_arcin_v6(struct expansion_card *ec)
  {
  	struct pata_icside_state *state = ec->irq_data;
  
  	return readb(state->irq_port + ICS_ARCIN_V6_INTRSTAT_1) & 1 ||
  	       readb(state->irq_port + ICS_ARCIN_V6_INTRSTAT_2) & 1;
  }
  
  static const expansioncard_ops_t pata_icside_ops_arcin_v6 = {
  	.irqenable	= pata_icside_irqenable_arcin_v6,
  	.irqdisable	= pata_icside_irqdisable_arcin_v6,
  	.irqpending	= pata_icside_irqpending_arcin_v6,
  };
  
  
  /*
   * SG-DMA support.
   *
   * Similar to the BM-DMA, but we use the RiscPCs IOMD DMA controllers.
   * There is only one DMA controller per card, which means that only
   * one drive can be accessed at one time.  NOTE! We do not enforce that
   * here, but we rely on the main IDE driver spotting that both
   * interfaces use the same IRQ, which should guarantee this.
   */
  
  /*
   * Configure the IOMD to give the appropriate timings for the transfer
   * mode being requested.  We take the advice of the ATA standards, and
   * calculate the cycle time based on the transfer mode, and the EIDE
   * MW DMA specs that the drive provides in the IDENTIFY command.
   *
   * We have the following IOMD DMA modes to choose from:
   *
   *	Type	Active		Recovery	Cycle
   *	A	250 (250)	312 (550)	562 (800)
   *	B	187 (200)	250 (550)	437 (750)
   *	C	125 (125)	125 (375)	250 (500)
   *	D	62  (50)	125 (375)	187 (425)
   *
   * (figures in brackets are actual measured timings on DIOR/DIOW)
   *
   * However, we also need to take care of the read/write active and
   * recovery timings:
   *
   *			Read	Write
   *  	Mode	Active	-- Recovery --	Cycle	IOMD type
   *	MW0	215	50	215	480	A
   *	MW1	80	50	50	150	C
   *	MW2	70	25	25	120	C
   */
  static void pata_icside_set_dmamode(struct ata_port *ap, struct ata_device *adev)
  {
  	struct pata_icside_state *state = ap->host->private_data;
  	struct ata_timing t;
  	unsigned int cycle;
  	char iomd_type;
  
  	/*
  	 * DMA is based on a 16MHz clock
  	 */
  	if (ata_timing_compute(adev, adev->dma_mode, &t, 1000, 1))
  		return;
  
  	/*
  	 * Choose the IOMD cycle timing which ensure that the interface
  	 * satisfies the measured active, recovery and cycle times.
  	 */
  	if (t.active <= 50 && t.recover <= 375 && t.cycle <= 425)
  		iomd_type = 'D', cycle = 187;
  	else if (t.active <= 125 && t.recover <= 375 && t.cycle <= 500)
  		iomd_type = 'C', cycle = 250;
  	else if (t.active <= 200 && t.recover <= 550 && t.cycle <= 750)
  		iomd_type = 'B', cycle = 437;
  	else
  		iomd_type = 'A', cycle = 562;

  	ata_dev_info(adev, "timings: act %dns rec %dns cyc %dns (%c)
  ",
  		     t.active, t.recover, t.cycle, iomd_type);

  
  	state->port[ap->port_no].speed[adev->devno] = cycle;
  }
  
  static void pata_icside_bmdma_setup(struct ata_queued_cmd *qc)
  {
  	struct ata_port *ap = qc->ap;
  	struct pata_icside_state *state = ap->host->private_data;

  	unsigned int write = qc->tf.flags & ATA_TFLAG_WRITE;
  
  	/*
  	 * We are simplex; BUG if we try to fiddle with DMA
  	 * while it's active.
  	 */
  	BUG_ON(dma_channel_active(state->dma));
  
  	/*

  	 * Route the DMA signals to the correct interface
  	 */
  	writeb(state->port[ap->port_no].port_sel, state->ioc_base);
  
  	set_dma_speed(state->dma, state->port[ap->port_no].speed[qc->dev->devno]);

  	set_dma_sg(state->dma, qc->sg, qc->n_elem);

  	set_dma_mode(state->dma, write ? DMA_MODE_WRITE : DMA_MODE_READ);
  
  	/* issue r/w command */

  	ap->ops->sff_exec_command(ap, &qc->tf);

  }
  
  static void pata_icside_bmdma_start(struct ata_queued_cmd *qc)
  {
  	struct ata_port *ap = qc->ap;
  	struct pata_icside_state *state = ap->host->private_data;
  
  	BUG_ON(dma_channel_active(state->dma));
  	enable_dma(state->dma);
  }
  
  static void pata_icside_bmdma_stop(struct ata_queued_cmd *qc)
  {
  	struct ata_port *ap = qc->ap;
  	struct pata_icside_state *state = ap->host->private_data;
  
  	disable_dma(state->dma);
  
  	/* see ata_bmdma_stop */

  	ata_sff_dma_pause(ap);

  }
  
  static u8 pata_icside_bmdma_status(struct ata_port *ap)
  {
  	struct pata_icside_state *state = ap->host->private_data;
  	void __iomem *irq_port;
  
  	irq_port = state->irq_port + (ap->port_no ? ICS_ARCIN_V6_INTRSTAT_2 :
  						    ICS_ARCIN_V6_INTRSTAT_1);
  
  	return readb(irq_port) & 1 ? ATA_DMA_INTR : 0;
  }

  static int icside_dma_init(struct pata_icside_info *info)

  {

  	struct pata_icside_state *state = info->state;
  	struct expansion_card *ec = info->ec;

  	int i;
  
  	for (i = 0; i < ATA_MAX_DEVICES; i++) {
  		state->port[0].speed[i] = 480;
  		state->port[1].speed[i] = 480;
  	}
  
  	if (ec->dma != NO_DMA && !request_dma(ec->dma, DRV_NAME)) {
  		state->dma = ec->dma;

  		info->mwdma_mask = ATA_MWDMA2;

  	}
  
  	return 0;
  }

  static struct scsi_host_template pata_icside_sht = {

  	ATA_BASE_SHT(DRV_NAME),

  	.sg_tablesize		= SG_MAX_SEGMENTS,

  	.dma_boundary		= IOMD_DMA_BOUNDARY,

  };

  static void pata_icside_postreset(struct ata_link *link, unsigned int *classes)

  {

  	struct ata_port *ap = link->ap;

  	struct pata_icside_state *state = ap->host->private_data;

  	if (classes[0] != ATA_DEV_NONE || classes[1] != ATA_DEV_NONE)

  		return ata_sff_postreset(link, classes);

  
  	state->port[ap->port_no].disabled = 1;
  
  	if (state->type == ICS_TYPE_V6) {
  		/*
  		 * Disable interrupts from this port, otherwise we
  		 * receive spurious interrupts from the floating
  		 * interrupt line.
  		 */
  		void __iomem *irq_port = state->irq_port +
  				(ap->port_no ? ICS_ARCIN_V6_INTROFFSET_2 : ICS_ARCIN_V6_INTROFFSET_1);
  		readb(irq_port);
  	}
  }

  static struct ata_port_operations pata_icside_port_ops = {

  	.inherits		= &ata_bmdma_port_ops,

  	/* no need to build any PRD tables for DMA */
  	.qc_prep		= ata_noop_qc_prep,

  	.sff_data_xfer		= ata_sff_data_xfer32,

  	.bmdma_setup		= pata_icside_bmdma_setup,
  	.bmdma_start		= pata_icside_bmdma_start,
  	.bmdma_stop		= pata_icside_bmdma_stop,
  	.bmdma_status		= pata_icside_bmdma_status,

  	.cable_detect		= ata_cable_40wire,
  	.set_dmamode		= pata_icside_set_dmamode,

  	.postreset		= pata_icside_postreset,

  	.port_start		= ATA_OP_NULL,	/* don't need PRD table */

  };

  static void pata_icside_setup_ioaddr(struct ata_port *ap, void __iomem *base,
  				     struct pata_icside_info *info,
  				     const struct portinfo *port)

  {

  	struct ata_ioports *ioaddr = &ap->ioaddr;

  	void __iomem *cmd = base + port->dataoffset;

  
  	ioaddr->cmd_addr	= cmd;

  	ioaddr->data_addr	= cmd + (ATA_REG_DATA    << port->stepping);
  	ioaddr->error_addr	= cmd + (ATA_REG_ERR     << port->stepping);
  	ioaddr->feature_addr	= cmd + (ATA_REG_FEATURE << port->stepping);
  	ioaddr->nsect_addr	= cmd + (ATA_REG_NSECT   << port->stepping);
  	ioaddr->lbal_addr	= cmd + (ATA_REG_LBAL    << port->stepping);
  	ioaddr->lbam_addr	= cmd + (ATA_REG_LBAM    << port->stepping);
  	ioaddr->lbah_addr	= cmd + (ATA_REG_LBAH    << port->stepping);
  	ioaddr->device_addr	= cmd + (ATA_REG_DEVICE  << port->stepping);
  	ioaddr->status_addr	= cmd + (ATA_REG_STATUS  << port->stepping);
  	ioaddr->command_addr	= cmd + (ATA_REG_CMD     << port->stepping);
  
  	ioaddr->ctl_addr	= base + port->ctrloffset;

  	ioaddr->altstatus_addr	= ioaddr->ctl_addr;

  
  	ata_port_desc(ap, "cmd 0x%lx ctl 0x%lx",

  		      info->raw_base + port->dataoffset,
  		      info->raw_base + port->ctrloffset);

  
  	if (info->raw_ioc_base)
  		ata_port_desc(ap, "iocbase 0x%lx", info->raw_ioc_base);

  }

  static int pata_icside_register_v5(struct pata_icside_info *info)

  {

  	struct pata_icside_state *state = info->state;

  	void __iomem *base;

  	base = ecardm_iomap(info->ec, ECARD_RES_MEMC, 0, 0);

  	if (!base)
  		return -ENOMEM;
  
  	state->irq_port = base;

  	info->base = base;
  	info->irqaddr = base + ICS_ARCIN_V5_INTRSTAT;
  	info->irqmask = 1;
  	info->irqops = &pata_icside_ops_arcin_v5;
  	info->nr_ports = 1;
  	info->port[0] = &pata_icside_portinfo_v5;

  	info->raw_base = ecard_resource_start(info->ec, ECARD_RES_MEMC);

  	return 0;
  }

  static int pata_icside_register_v6(struct pata_icside_info *info)

  {

  	struct pata_icside_state *state = info->state;
  	struct expansion_card *ec = info->ec;

  	void __iomem *ioc_base, *easi_base;
  	unsigned int sel = 0;

  	ioc_base = ecardm_iomap(ec, ECARD_RES_IOCFAST, 0, 0);
  	if (!ioc_base)
  		return -ENOMEM;

  
  	easi_base = ioc_base;
  
  	if (ecard_resource_flags(ec, ECARD_RES_EASI)) {

  		easi_base = ecardm_iomap(ec, ECARD_RES_EASI, 0, 0);
  		if (!easi_base)
  			return -ENOMEM;

  
  		/*
  		 * Enable access to the EASI region.
  		 */
  		sel = 1 << 5;
  	}
  
  	writeb(sel, ioc_base);

  	state->irq_port = easi_base;
  	state->ioc_base = ioc_base;
  	state->port[0].port_sel = sel;
  	state->port[1].port_sel = sel | 1;

  	info->base = easi_base;
  	info->irqops = &pata_icside_ops_arcin_v6;
  	info->nr_ports = 2;
  	info->port[0] = &pata_icside_portinfo_v6_1;
  	info->port[1] = &pata_icside_portinfo_v6_2;

  	info->raw_base = ecard_resource_start(ec, ECARD_RES_EASI);
  	info->raw_ioc_base = ecard_resource_start(ec, ECARD_RES_IOCFAST);

  	return icside_dma_init(info);
  }

  static int pata_icside_add_ports(struct pata_icside_info *info)

  {
  	struct expansion_card *ec = info->ec;
  	struct ata_host *host;
  	int i;
  
  	if (info->irqaddr) {
  		ec->irqaddr = info->irqaddr;
  		ec->irqmask = info->irqmask;
  	}
  	if (info->irqops)
  		ecard_setirq(ec, info->irqops, info->state);
  
  	/*
  	 * Be on the safe side - disable interrupts
  	 */
  	ec->ops->irqdisable(ec, ec->irq);
  
  	host = ata_host_alloc(&ec->dev, info->nr_ports);
  	if (!host)
  		return -ENOMEM;
  
  	host->private_data = info->state;
  	host->flags = ATA_HOST_SIMPLEX;
  
  	for (i = 0; i < info->nr_ports; i++) {
  		struct ata_port *ap = host->ports[i];

  		ap->pio_mask = ATA_PIO4;

  		ap->mwdma_mask = info->mwdma_mask;

  		ap->flags |= ATA_FLAG_SLAVE_POSS;

  		ap->ops = &pata_icside_port_ops;

  		pata_icside_setup_ioaddr(ap, info->base, info, info->port[i]);

  	}

  	return ata_host_activate(host, ec->irq, ata_bmdma_interrupt, 0,

  				 &pata_icside_sht);

  }

  static int pata_icside_probe(struct expansion_card *ec,
  			     const struct ecard_id *id)

  {
  	struct pata_icside_state *state;

  	struct pata_icside_info info;

  	void __iomem *idmem;
  	int ret;
  
  	ret = ecard_request_resources(ec);
  	if (ret)
  		goto out;

  	state = devm_kzalloc(&ec->dev, sizeof(*state), GFP_KERNEL);

  	if (!state) {
  		ret = -ENOMEM;
  		goto release;
  	}
  
  	state->type = ICS_TYPE_NOTYPE;
  	state->dma = NO_DMA;

  	idmem = ecardm_iomap(ec, ECARD_RES_IOCFAST, 0, 0);

  	if (idmem) {
  		unsigned int type;
  
  		type = readb(idmem + ICS_IDENT_OFFSET) & 1;
  		type |= (readb(idmem + ICS_IDENT_OFFSET + 4) & 1) << 1;
  		type |= (readb(idmem + ICS_IDENT_OFFSET + 8) & 1) << 2;
  		type |= (readb(idmem + ICS_IDENT_OFFSET + 12) & 1) << 3;

  		ecardm_iounmap(ec, idmem);

  
  		state->type = type;
  	}

  	memset(&info, 0, sizeof(info));
  	info.state = state;
  	info.ec = ec;

  
  	switch (state->type) {
  	case ICS_TYPE_A3IN:
  		dev_warn(&ec->dev, "A3IN unsupported
  ");
  		ret = -ENODEV;
  		break;
  
  	case ICS_TYPE_A3USER:
  		dev_warn(&ec->dev, "A3USER unsupported
  ");
  		ret = -ENODEV;
  		break;
  
  	case ICS_TYPE_V5:

  		ret = pata_icside_register_v5(&info);

  		break;
  
  	case ICS_TYPE_V6:

  		ret = pata_icside_register_v6(&info);

  		break;
  
  	default:
  		dev_warn(&ec->dev, "unknown interface type
  ");
  		ret = -ENODEV;
  		break;
  	}
  
  	if (ret == 0)

  		ret = pata_icside_add_ports(&info);

  
  	if (ret == 0)
  		goto out;

   release:
  	ecard_release_resources(ec);
   out:
  	return ret;
  }
  
  static void pata_icside_shutdown(struct expansion_card *ec)
  {
  	struct ata_host *host = ecard_get_drvdata(ec);
  	unsigned long flags;
  
  	/*
  	 * Disable interrupts from this card.  We need to do
  	 * this before disabling EASI since we may be accessing
  	 * this register via that region.
  	 */
  	local_irq_save(flags);

  	ec->ops->irqdisable(ec, ec->irq);

  	local_irq_restore(flags);
  
  	/*
  	 * Reset the ROM pointer so that we can read the ROM
  	 * after a soft reboot.  This also disables access to
  	 * the IDE taskfile via the EASI region.
  	 */
  	if (host) {
  		struct pata_icside_state *state = host->private_data;
  		if (state->ioc_base)
  			writeb(0, state->ioc_base);
  	}
  }

  static void pata_icside_remove(struct expansion_card *ec)

  {
  	struct ata_host *host = ecard_get_drvdata(ec);
  	struct pata_icside_state *state = host->private_data;
  
  	ata_host_detach(host);
  
  	pata_icside_shutdown(ec);
  
  	/*
  	 * don't NULL out the drvdata - devres/libata wants it
  	 * to free the ata_host structure.
  	 */

  	if (state->dma != NO_DMA)
  		free_dma(state->dma);

  	ecard_release_resources(ec);
  }
  
  static const struct ecard_id pata_icside_ids[] = {
  	{ MANU_ICS,  PROD_ICS_IDE  },
  	{ MANU_ICS2, PROD_ICS2_IDE },
  	{ 0xffff, 0xffff }
  };
  
  static struct ecard_driver pata_icside_driver = {
  	.probe		= pata_icside_probe,

  	.remove 	= pata_icside_remove,

  	.shutdown	= pata_icside_shutdown,
  	.id_table	= pata_icside_ids,
  	.drv = {
  		.name	= DRV_NAME,
  	},
  };
  
  static int __init pata_icside_init(void)
  {
  	return ecard_register_driver(&pata_icside_driver);
  }
  
  static void __exit pata_icside_exit(void)
  {
  	ecard_remove_driver(&pata_icside_driver);
  }
  
  MODULE_AUTHOR("Russell King <rmk@arm.linux.org.uk>");
  MODULE_LICENSE("GPL");
  MODULE_DESCRIPTION("ICS PATA driver");
  
  module_init(pata_icside_init);
  module_exit(pata_icside_exit);