/*
 * linux/drivers/block/icside.c
 *
 * Copyright (c) 1996,1997 Russell King.
 *
 * Changelog:
 *  08-Jun-1996	RMK	Created
 *  12-Sep-1997	RMK	Added interrupt enable/disable
 *  17-Apr-1999	RMK	Added support for V6 EASI
 *  22-May-1999	RMK	Added support for V6 DMA
 */

#include <linux/config.h>
#include <linux/string.h>
#include <linux/module.h>
#include <linux/ioport.h>
#include <linux/malloc.h>
#include <linux/blkdev.h>
#include <linux/errno.h>
#include <linux/hdreg.h>
#include <linux/ide.h>

#include <asm/dma.h>
#include <asm/ecard.h>
#include <asm/io.h>

/*
 * Maximum number of interfaces per card
 */
#define MAX_IFS	2

#define ICS_IDENT_OFFSET		0x8a0

#define ICS_ARCIN_V5_INTRSTAT		0x000
#define ICS_ARCIN_V5_INTROFFSET		0x001
#define ICS_ARCIN_V5_IDEOFFSET		0xa00
#define ICS_ARCIN_V5_IDEALTOFFSET	0xae0
#define ICS_ARCIN_V5_IDESTEPPING	4

#define ICS_ARCIN_V6_IDEOFFSET_1	0x800
#define ICS_ARCIN_V6_INTROFFSET_1	0x880
#define ICS_ARCIN_V6_INTRSTAT_1		0x8a4
#define ICS_ARCIN_V6_IDEALTOFFSET_1	0x8e0
#define ICS_ARCIN_V6_IDEOFFSET_2	0xc00
#define ICS_ARCIN_V6_INTROFFSET_2	0xc80
#define ICS_ARCIN_V6_INTRSTAT_2		0xca4
#define ICS_ARCIN_V6_IDEALTOFFSET_2	0xce0
#define ICS_ARCIN_V6_IDESTEPPING	4

struct cardinfo {
	unsigned int dataoffset;
	unsigned int ctrloffset;
	unsigned int stepping;
};

static struct cardinfo icside_cardinfo_v5 = {
	ICS_ARCIN_V5_IDEOFFSET,
	ICS_ARCIN_V5_IDEALTOFFSET,
	ICS_ARCIN_V5_IDESTEPPING
};

static struct cardinfo icside_cardinfo_v6_1 = {
	ICS_ARCIN_V6_IDEOFFSET_1,
	ICS_ARCIN_V6_IDEALTOFFSET_1,
	ICS_ARCIN_V6_IDESTEPPING
};

static struct cardinfo icside_cardinfo_v6_2 = {
	ICS_ARCIN_V6_IDEOFFSET_2,
	ICS_ARCIN_V6_IDEALTOFFSET_2,
	ICS_ARCIN_V6_IDESTEPPING
};

static const card_ids icside_cids[] = {
	{ MANU_ICS,  PROD_ICS_IDE  },
	{ MANU_ICS2, PROD_ICS2_IDE },
	{ 0xffff, 0xffff }
};

typedef enum {
	ics_if_unknown,
	ics_if_arcin_v5,
	ics_if_arcin_v6
} iftype_t;

/* ---------------- Version 5 PCB Support Functions --------------------- */
/* Prototype: icside_irqenable_arcin_v5 (struct expansion_card *ec, int irqnr)
 * Purpose  : enable interrupts from card
 */
static void icside_irqenable_arcin_v5 (struct expansion_card *ec, int irqnr)
{
	unsigned int memc_port = (unsigned int)ec->irq_data;
	outb (0, memc_port + ICS_ARCIN_V5_INTROFFSET);
}

/* Prototype: icside_irqdisable_arcin_v5 (struct expansion_card *ec, int irqnr)
 * Purpose  : disable interrupts from card
 */
static void icside_irqdisable_arcin_v5 (struct expansion_card *ec, int irqnr)
{
	unsigned int memc_port = (unsigned int)ec->irq_data;
	inb (memc_port + ICS_ARCIN_V5_INTROFFSET);
}

static const expansioncard_ops_t icside_ops_arcin_v5 = {
	icside_irqenable_arcin_v5,
	icside_irqdisable_arcin_v5,
	NULL,
	NULL,
	NULL,
	NULL
};


/* ---------------- Version 6 PCB Support Functions --------------------- */
/* Prototype: icside_irqenable_arcin_v6 (struct expansion_card *ec, int irqnr)
 * Purpose  : enable interrupts from card
 */
static void icside_irqenable_arcin_v6 (struct expansion_card *ec, int irqnr)
{
	unsigned int ide_base_port = (unsigned int)ec->irq_data;

	outb (0, ide_base_port + ICS_ARCIN_V6_INTROFFSET_1);
	outb (0, ide_base_port + ICS_ARCIN_V6_INTROFFSET_2);
}

/* Prototype: icside_irqdisable_arcin_v6 (struct expansion_card *ec, int irqnr)
 * Purpose  : disable interrupts from card
 */
static void icside_irqdisable_arcin_v6 (struct expansion_card *ec, int irqnr)
{
	unsigned int ide_base_port = (unsigned int)ec->irq_data;

	inb (ide_base_port + ICS_ARCIN_V6_INTROFFSET_1);
	inb (ide_base_port + ICS_ARCIN_V6_INTROFFSET_2);
}

/* Prototype: icside_irqprobe(struct expansion_card *ec)
 * Purpose  : detect an active interrupt from card
 */
static int icside_irqpending_arcin_v6(struct expansion_card *ec)
{
	unsigned int ide_base_port = (unsigned int)ec->irq_data;

	return inb(ide_base_port + ICS_ARCIN_V6_INTRSTAT_1) & 1 ||
	       inb(ide_base_port + ICS_ARCIN_V6_INTRSTAT_2) & 1;
}

static const expansioncard_ops_t icside_ops_arcin_v6 = {
	icside_irqenable_arcin_v6,
	icside_irqdisable_arcin_v6,
	icside_irqpending_arcin_v6,
	NULL,
	NULL,
	NULL
};

/* Prototype: icside_identifyif (struct expansion_card *ec)
 * Purpose  : identify IDE interface type
 * Notes    : checks the description string
 */
static iftype_t icside_identifyif (struct expansion_card *ec)
{
	unsigned int addr;
	iftype_t iftype;
	int id = 0;

	iftype = ics_if_unknown;

	addr = ecard_address (ec, ECARD_IOC, ECARD_FAST) + ICS_IDENT_OFFSET;

	id = inb (addr) & 1;
	id |= (inb (addr + 1) & 1) << 1;
	id |= (inb (addr + 2) & 1) << 2;
	id |= (inb (addr + 3) & 1) << 3;

	switch (id) {
	case 0: /* A3IN */
		printk("icside: A3IN unsupported\n");
		break;

	case 1: /* A3USER */
		printk("icside: A3USER unsupported\n");
		break;

	case 3:	/* ARCIN V6 */
		printk(KERN_DEBUG "icside: detected ARCIN V6 in slot %d\n", ec->slot_no);
		iftype = ics_if_arcin_v6;
		break;

	case 15:/* ARCIN V5 (no id) */
		printk(KERN_DEBUG "icside: detected ARCIN V5 in slot %d\n", ec->slot_no);
		iftype = ics_if_arcin_v5;
		break;

	default:/* we don't know - complain very loudly */
		printk("icside: ***********************************\n");
		printk("icside: *** UNKNOWN ICS INTERFACE id=%d ***\n", id);
		printk("icside: ***********************************\n");
		printk("icside: please report this to linux@arm.linux.org.uk\n");
		printk("icside: defaulting to ARCIN V5\n");
		iftype = ics_if_arcin_v5;
		break;
	}

	return iftype;
}

#ifdef CONFIG_BLK_DEV_IDEDMA_ICS
/*
 * 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.
 */
#define TABLE_SIZE 2048

static int
icside_build_dmatable(ide_drive_t *drive, int reading)
{
	struct request *rq = HWGROUP(drive)->rq;
	struct buffer_head *bh = rq->bh;
	unsigned long addr, size;
	unsigned char *virt_addr;
	unsigned int count = 0;
	dmasg_t *sg = (dmasg_t *)HWIF(drive)->dmatable_cpu;

	do {
		if (bh == NULL) {
			/* paging requests have (rq->bh == NULL) */
			virt_addr = rq->buffer;
			addr = virt_to_bus (virt_addr);
			size = rq->nr_sectors << 9;
		} else {
			/* group sequential buffers into one large buffer */
			virt_addr = bh->b_data;
			addr = virt_to_bus (virt_addr);
			size = bh->b_size;
			while ((bh = bh->b_reqnext) != NULL) {
				if ((addr + size) != virt_to_bus (bh->b_data))
					break;
				size += bh->b_size;
			}
		}

		if (addr & 3) {
			printk("%s: misaligned DMA buffer\n", drive->name);
			return 0;
		}

		if (size) {
			if (reading)
				dma_cache_inv((unsigned int)virt_addr, size);
			else
				dma_cache_wback((unsigned int)virt_addr, size);
		}

		sg[count].address = addr;
		sg[count].length = size;
		if (++count >= (TABLE_SIZE / sizeof(dmasg_t))) {
			printk("%s: DMA table too small\n", drive->name);
			return 0;
		}
	} while (bh != NULL);

	if (!count)
		printk("%s: empty DMA table?\n", drive->name);

	return count;
}

static int
icside_config_if(ide_drive_t *drive, int xfer_mode)
{
	int func = ide_dma_off;

	switch (xfer_mode) {
	case XFER_MW_DMA_2:
		/*
		 * The cycle time is limited to 250ns by the r/w
		 * pulse width (90ns), however we should still
		 * have a maximum burst transfer rate of 8MB/s.
		 */
		drive->drive_data = 250;
		break;

	case XFER_MW_DMA_1:
		drive->drive_data = 250;
		break;

	case XFER_MW_DMA_0:
		drive->drive_data = 480;
		break;

	default:
		drive->drive_data = 0;
		break;
	}

	if (drive->drive_data &&
	    ide_config_drive_speed(drive, (byte) xfer_mode) == 0)
		func = ide_dma_on;
	else
		drive->drive_data = 480;

	printk("%s: %s selected (peak %dMB/s)\n", drive->name,
		ide_xfer_verbose(xfer_mode), 2000 / drive->drive_data);

	return func;
}

static int
icside_dma_check(ide_drive_t *drive)
{
	struct hd_driveid *id = drive->id;
	ide_hwif_t *hwif = HWIF(drive);
	int autodma = hwif->autodma;
	int xfer_mode = XFER_PIO_2;
	int func = ide_dma_off_quietly;

	if (!id || !(id->capability & 1) || !autodma)
		goto out;

	/*
	 * Consult the list of known "bad" drives
	 */
	if (ide_dmaproc(ide_dma_bad_drive, drive)) {
		func = ide_dma_off;
		goto out;
	}

	/*
	 * Enable DMA on any drive that has multiword DMA
	 */
	if (id->field_valid & 2) {
		if (id->dma_mword & 4) {
			xfer_mode = XFER_MW_DMA_2;
			func = ide_dma_on;
		} else if (id->dma_mword & 2) {
			xfer_mode = XFER_MW_DMA_1;
			func = ide_dma_on;
		} else if (id->dma_mword & 1) {
			xfer_mode = XFER_MW_DMA_0;
			func = ide_dma_on;
		}
		goto out;
	}

	/*
	 * Consult the list of known "good" drives
	 */
	if (ide_dmaproc(ide_dma_good_drive, drive)) {
		if (id->eide_dma_time > 150)
			goto out;
		xfer_mode = XFER_MW_DMA_1;
		func = ide_dma_on;
	}

out:
	func = icside_config_if(drive, xfer_mode);

	return hwif->dmaproc(func, drive);
}

static int
icside_dmaproc(ide_dma_action_t func, ide_drive_t *drive)
{
	ide_hwif_t *hwif = HWIF(drive);
	int count, reading = 0;

	switch (func) {
	case ide_dma_check:
		return icside_dma_check(drive);

	case ide_dma_read:
		reading = 1;
	case ide_dma_write:
		count = icside_build_dmatable(drive, reading);
		if (!count)
			return 1;
		disable_dma(hwif->hw.dma);

		/* Route the DMA signals to
		 * to the correct interface.
		 */
		outb(hwif->select_data, hwif->config_data);

		/* Select the correct timing
		 * for this drive
		 */
		set_dma_speed(hwif->hw.dma, drive->drive_data);

		set_dma_sg(hwif->hw.dma, (dmasg_t *)hwif->dmatable_cpu, count);
		set_dma_mode(hwif->hw.dma, reading ? DMA_MODE_READ
			     : DMA_MODE_WRITE);

		drive->waiting_for_dma = 1;
		if (drive->media != ide_disk)
			return 0;

		ide_set_handler(drive, &ide_dma_intr, WAIT_CMD, NULL);
		OUT_BYTE(reading ? WIN_READDMA : WIN_WRITEDMA,
			 IDE_COMMAND_REG);

	case ide_dma_begin:
		enable_dma(hwif->hw.dma);
		return 0;

	case ide_dma_end:
		drive->waiting_for_dma = 0;
		disable_dma(hwif->hw.dma);
		return get_dma_residue(hwif->hw.dma) != 0;

	case ide_dma_test_irq:
		return inb((unsigned long)hwif->hw.priv) & 1;

	default:
		return ide_dmaproc(func, drive);
	}
}

static unsigned long
icside_alloc_dmatable(void)
{
	static unsigned long dmatable;
	static unsigned int leftover;
	unsigned long table;

	if (leftover < TABLE_SIZE) {
#if PAGE_SIZE == TABLE_SIZE * 2
		dmatable = __get_free_pages(GFP_KERNEL, 1);
		leftover = PAGE_SIZE;
#else
		dmatable = kmalloc(TABLE_SIZE, GFP_KERNEL);
		leftover = TABLE_SIZE;
#endif
	}

	table = dmatable;
	if (table) {
		dmatable += TABLE_SIZE;
		leftover -= TABLE_SIZE;
	}

	return table;
}

static int
icside_setup_dma(ide_hwif_t *hwif, int autodma)
{
	unsigned long table = icside_alloc_dmatable();

	printk("    %s: SG-DMA", hwif->name);

	if (!table)
		printk(" -- ERROR, unable to allocate DMA table\n");
	else {
		hwif->dmatable_cpu = (void *)table;
		hwif->dmaproc = icside_dmaproc;
		hwif->autodma = autodma;

		printk(" capable%s\n", autodma ?
			", auto-enable" : "");
	}

	return hwif->dmatable_cpu != NULL;
}
#endif

static ide_hwif_t *
icside_find_hwif(unsigned long dataport)
{
	ide_hwif_t *hwif;
	int index;

	for (index = 0; index < MAX_HWIFS; ++index) {
		hwif = &ide_hwifs[index];
		if (hwif->hw.io_ports[IDE_DATA_OFFSET] == (ide_ioreg_t)dataport)
			goto found;
	}

	for (index = 0; index < MAX_HWIFS; ++index) {
		hwif = &ide_hwifs[index];
		if (!hwif->hw.io_ports[IDE_DATA_OFFSET])
			goto found;
	}

	return NULL;
found:
	return hwif;
}

static ide_hwif_t *
icside_setup(unsigned long base, struct cardinfo *info, int irq)
{
	unsigned long port = base + info->dataoffset;
	ide_hwif_t *hwif;

	hwif = icside_find_hwif(base);
	if (hwif) {
		int i;

		memset(&hwif->hw, 0, sizeof(hw_regs_t));

		for (i = IDE_DATA_OFFSET; i <= IDE_STATUS_OFFSET; i++) {
			hwif->hw.io_ports[i] = (ide_ioreg_t)port;
			port += 1 << info->stepping;
		}
		hwif->hw.io_ports[IDE_CONTROL_OFFSET] = base + info->ctrloffset;
		hwif->hw.irq  = irq;
		hwif->hw.dma  = NO_DMA;
		hwif->noprobe = 0;
		hwif->chipset = ide_acorn;
	}

	return hwif;
}

static int icside_register_v5(struct expansion_card *ec, int autodma)
{
	unsigned long slot_port;
	ide_hwif_t *hwif;

	slot_port = ecard_address(ec, ECARD_MEMC, 0);

	ec->irqaddr  = (unsigned char *)ioaddr(slot_port + ICS_ARCIN_V5_INTRSTAT);
	ec->irqmask  = 1;
	ec->irq_data = (void *)slot_port;
	ec->ops      = (expansioncard_ops_t *)&icside_ops_arcin_v5;

	/*
	 * Be on the safe side - disable interrupts
	 */
	inb(slot_port + ICS_ARCIN_V5_INTROFFSET);

	hwif = icside_setup(slot_port, &icside_cardinfo_v5, ec->irq);

	return hwif ? 0 : -1;
}

static int icside_register_v6(struct expansion_card *ec, int autodma)
{
	unsigned long slot_port, port;
	ide_hwif_t *hwif, *mate;
	int sel = 0;

	slot_port = ecard_address(ec, ECARD_IOC, ECARD_FAST);
	port      = ecard_address(ec, ECARD_EASI, ECARD_FAST);

	if (port == 0)
		port = slot_port;
	else
		sel = 1 << 5;

	outb(sel, slot_port);

	ec->irq_data = (void *)port;
	ec->ops      = (expansioncard_ops_t *)&icside_ops_arcin_v6;

	/*
	 * Be on the safe side - disable interrupts
	 */
	inb(port + ICS_ARCIN_V6_INTROFFSET_1);
	inb(port + ICS_ARCIN_V6_INTROFFSET_2);

	hwif = icside_setup(port, &icside_cardinfo_v6_1, ec->irq);
	mate = icside_setup(port, &icside_cardinfo_v6_2, ec->irq);

#ifdef CONFIG_BLK_DEV_IDEDMA_ICS
	if (ec->dma != NO_DMA) {
		if (request_dma(ec->dma, hwif->name))
			goto no_dma;

		if (hwif) {
			hwif->config_data = slot_port;
			hwif->select_data = sel;
			hwif->hw.dma  = ec->dma;
			hwif->hw.priv = (void *)
					(port + ICS_ARCIN_V6_INTRSTAT_1);
			hwif->channel = 0;
			icside_setup_dma(hwif, autodma);
		}
		if (mate) {
			mate->config_data = slot_port;
			mate->select_data = sel | 1;
			mate->hw.dma  = ec->dma;
			mate->hw.priv = (void *)
					(port + ICS_ARCIN_V6_INTRSTAT_2);
			mate->channel = 1;
			icside_setup_dma(mate, autodma);
		}
	}
#endif

no_dma:
	return hwif || mate ? 0 : -1;
}

int icside_init(void)
{
	int autodma = 0;

#ifdef CONFIG_IDEDMA_ICS_AUTO
	autodma = 1;
#endif

	ecard_startfind ();

	do {
		struct expansion_card *ec;
		int result;

		ec = ecard_find(0, icside_cids);
		if (ec == NULL)
			break;

		ecard_claim(ec);

		switch (icside_identifyif(ec)) {
		case ics_if_arcin_v5:
			result = icside_register_v5(ec, autodma);
			break;

		case ics_if_arcin_v6:
			result = icside_register_v6(ec, autodma);
			break;

		default:
			result = -1;
			break;
		}

		if (result)
			ecard_release(ec);
	} while (1);

	return 0;
}