/*
 *  Support for the interrupt controllers found on Power Macintosh,
 *  currently Apple's "Grand Central" interrupt controller in all
 *  it's incarnations. OpenPIC support used on newer machines is
 *  in a separate file
 *
 *  Copyright (C) 1997 Paul Mackerras (paulus@cs.anu.edu.au)
 *
 *  Maintained by Benjamin Herrenschmidt (benh@kernel.crashing.org)
 *
 *  This program is free software; you can redistribute it and/or
 *  modify it under the terms of the GNU General Public License
 *  as published by the Free Software Foundation; either version
 *  2 of the License, or (at your option) any later version.
 *
 */

#include <linux/config.h>
#include <linux/stddef.h>
#include <linux/init.h>
#include <linux/sched.h>
#include <linux/signal.h>
#include <linux/pci.h>
#include <linux/interrupt.h>
#include <linux/sysdev.h>
#include <linux/adb.h>
#include <linux/pmu.h>

#include <asm/sections.h>
#include <asm/io.h>
#include <asm/smp.h>
#include <asm/prom.h>
#include <asm/pci-bridge.h>
#include <asm/time.h>
#include <asm/open_pic.h>
#include <asm/xmon.h>
#include <asm/pmac_feature.h>

#include "pmac_pic.h"

/*
 * XXX this should be in xmon.h, but putting it there means xmon.h
 * has to include <linux/interrupt.h> (to get irqreturn_t), which
 * causes all sorts of problems.  -- paulus
 */
extern irqreturn_t xmon_irq(int, void *, struct pt_regs *);

struct pmac_irq_hw {
        unsigned int    event;
        unsigned int    enable;
        unsigned int    ack;
        unsigned int    level;
};

/* Default addresses */
static volatile struct pmac_irq_hw *pmac_irq_hw[4] __pmacdata = {
        (struct pmac_irq_hw *) 0xf3000020,
        (struct pmac_irq_hw *) 0xf3000010,
        (struct pmac_irq_hw *) 0xf4000020,
        (struct pmac_irq_hw *) 0xf4000010,
};

#define GC_LEVEL_MASK		0x3ff00000
#define OHARE_LEVEL_MASK	0x1ff00000
#define HEATHROW_LEVEL_MASK	0x1ff00000

static int max_irqs __pmacdata;
static int max_real_irqs __pmacdata;
static u32 level_mask[4] __pmacdata;

static DEFINE_SPINLOCK(pmac_pic_lock __pmacdata);


#define GATWICK_IRQ_POOL_SIZE        10
static struct interrupt_info gatwick_int_pool[GATWICK_IRQ_POOL_SIZE] __pmacdata;

/*
 * Mark an irq as "lost".  This is only used on the pmac
 * since it can lose interrupts (see pmac_set_irq_mask).
 * -- Cort
 */
void __pmac
__set_lost(unsigned long irq_nr, int nokick)
{
	if (!test_and_set_bit(irq_nr, ppc_lost_interrupts)) {
		atomic_inc(&ppc_n_lost_interrupts);
		if (!nokick)
			set_dec(1);
	}
}

static void __pmac
pmac_mask_and_ack_irq(unsigned int irq_nr)
{
        unsigned long bit = 1UL << (irq_nr & 0x1f);
        int i = irq_nr >> 5;
        unsigned long flags;

        if ((unsigned)irq_nr >= max_irqs)
                return;

        clear_bit(irq_nr, ppc_cached_irq_mask);
        if (test_and_clear_bit(irq_nr, ppc_lost_interrupts))
                atomic_dec(&ppc_n_lost_interrupts);
	spin_lock_irqsave(&pmac_pic_lock, flags);
        out_le32(&pmac_irq_hw[i]->enable, ppc_cached_irq_mask[i]);
        out_le32(&pmac_irq_hw[i]->ack, bit);
        do {
                /* make sure ack gets to controller before we enable
                   interrupts */
                mb();
        } while((in_le32(&pmac_irq_hw[i]->enable) & bit)
                != (ppc_cached_irq_mask[i] & bit));
	spin_unlock_irqrestore(&pmac_pic_lock, flags);
}

static void __pmac pmac_set_irq_mask(unsigned int irq_nr, int nokicklost)
{
        unsigned long bit = 1UL << (irq_nr & 0x1f);
        int i = irq_nr >> 5;
        unsigned long flags;

        if ((unsigned)irq_nr >= max_irqs)
                return;

	spin_lock_irqsave(&pmac_pic_lock, flags);
        /* enable unmasked interrupts */
        out_le32(&pmac_irq_hw[i]->enable, ppc_cached_irq_mask[i]);

        do {
                /* make sure mask gets to controller before we
                   return to user */
                mb();
        } while((in_le32(&pmac_irq_hw[i]->enable) & bit)
                != (ppc_cached_irq_mask[i] & bit));

        /*
         * Unfortunately, setting the bit in the enable register
         * when the device interrupt is already on *doesn't* set
         * the bit in the flag register or request another interrupt.
         */
        if (bit & ppc_cached_irq_mask[i] & in_le32(&pmac_irq_hw[i]->level))
		__set_lost((ulong)irq_nr, nokicklost);
	spin_unlock_irqrestore(&pmac_pic_lock, flags);
}

/* When an irq gets requested for the first client, if it's an
 * edge interrupt, we clear any previous one on the controller
 */
static unsigned int __pmac pmac_startup_irq(unsigned int irq_nr)
{
        unsigned long bit = 1UL << (irq_nr & 0x1f);
        int i = irq_nr >> 5;

	if ((irq_desc[irq_nr].status & IRQ_LEVEL) == 0)
		out_le32(&pmac_irq_hw[i]->ack, bit);
        set_bit(irq_nr, ppc_cached_irq_mask);
        pmac_set_irq_mask(irq_nr, 0);

	return 0;
}

static void __pmac pmac_mask_irq(unsigned int irq_nr)
{
        clear_bit(irq_nr, ppc_cached_irq_mask);
        pmac_set_irq_mask(irq_nr, 0);
        mb();
}

static void __pmac pmac_unmask_irq(unsigned int irq_nr)
{
        set_bit(irq_nr, ppc_cached_irq_mask);
        pmac_set_irq_mask(irq_nr, 0);
}

static void __pmac pmac_end_irq(unsigned int irq_nr)
{
	if (!(irq_desc[irq_nr].status & (IRQ_DISABLED|IRQ_INPROGRESS))
	    && irq_desc[irq_nr].action) {
        	set_bit(irq_nr, ppc_cached_irq_mask);
	        pmac_set_irq_mask(irq_nr, 1);
	}
}


struct hw_interrupt_type pmac_pic = {
	.typename	= " PMAC-PIC ",
	.startup	= pmac_startup_irq,
	.enable		= pmac_unmask_irq,
	.disable	= pmac_mask_irq,
	.ack		= pmac_mask_and_ack_irq,
	.end		= pmac_end_irq,
};

struct hw_interrupt_type gatwick_pic = {
	.typename	= " GATWICK  ",
	.startup	= pmac_startup_irq,
	.enable		= pmac_unmask_irq,
	.disable	= pmac_mask_irq,
	.ack		= pmac_mask_and_ack_irq,
	.end		= pmac_end_irq,
};

static irqreturn_t gatwick_action(int cpl, void *dev_id, struct pt_regs *regs)
{
	int irq, bits;

	for (irq = max_irqs; (irq -= 32) >= max_real_irqs; ) {
		int i = irq >> 5;
		bits = in_le32(&pmac_irq_hw[i]->event) | ppc_lost_interrupts[i];
		/* We must read level interrupts from the level register */
		bits |= (in_le32(&pmac_irq_hw[i]->level) & level_mask[i]);
		bits &= ppc_cached_irq_mask[i];
		if (bits == 0)
			continue;
		irq += __ilog2(bits);
		__do_IRQ(irq, regs);
		return IRQ_HANDLED;
	}
	printk("gatwick irq not from gatwick pic\n");
	return IRQ_NONE;
}

int
pmac_get_irq(struct pt_regs *regs)
{
	int irq;
	unsigned long bits = 0;

#ifdef CONFIG_SMP
	void psurge_smp_message_recv(struct pt_regs *);

       	/* IPI's are a hack on the powersurge -- Cort */
       	if ( smp_processor_id() != 0 ) {
		psurge_smp_message_recv(regs);
		return -2;	/* ignore, already handled */
        }
#endif /* CONFIG_SMP */
	for (irq = max_real_irqs; (irq -= 32) >= 0; ) {
		int i = irq >> 5;
		bits = in_le32(&pmac_irq_hw[i]->event) | ppc_lost_interrupts[i];
		/* We must read level interrupts from the level register */
		bits |= (in_le32(&pmac_irq_hw[i]->level) & level_mask[i]);
		bits &= ppc_cached_irq_mask[i];
		if (bits == 0)
			continue;
		irq += __ilog2(bits);
		break;
	}

	return irq;
}

/* This routine will fix some missing interrupt values in the device tree
 * on the gatwick mac-io controller used by some PowerBooks
 */
static void __init
pmac_fix_gatwick_interrupts(struct device_node *gw, int irq_base)
{
	struct device_node *node;
	int count;

	memset(gatwick_int_pool, 0, sizeof(gatwick_int_pool));
	node = gw->child;
	count = 0;
	while(node)
	{
		/* Fix SCC */
		if (strcasecmp(node->name, "escc") == 0)
			if (node->child) {
				if (node->child->n_intrs < 3) {
					node->child->intrs = &gatwick_int_pool[count];
					count += 3;
				}
				node->child->n_intrs = 3;
				node->child->intrs[0].line = 15+irq_base;
				node->child->intrs[1].line =  4+irq_base;
				node->child->intrs[2].line =  5+irq_base;
				printk(KERN_INFO "irq: fixed SCC on second controller (%d,%d,%d)\n",
					node->child->intrs[0].line,
					node->child->intrs[1].line,
					node->child->intrs[2].line);
			}
		/* Fix media-bay & left SWIM */
		if (strcasecmp(node->name, "media-bay") == 0) {
			struct device_node* ya_node;

			if (node->n_intrs == 0)
				node->intrs = &gatwick_int_pool[count++];
			node->n_intrs = 1;
			node->intrs[0].line = 29+irq_base;
			printk(KERN_INFO "irq: fixed media-bay on second controller (%d)\n",
					node->intrs[0].line);

			ya_node = node->child;
			while(ya_node)
			{
				if (strcasecmp(ya_node->name, "floppy") == 0) {
					if (ya_node->n_intrs < 2) {
						ya_node->intrs = &gatwick_int_pool[count];
						count += 2;
					}
					ya_node->n_intrs = 2;
					ya_node->intrs[0].line = 19+irq_base;
					ya_node->intrs[1].line =  1+irq_base;
					printk(KERN_INFO "irq: fixed floppy on second controller (%d,%d)\n",
						ya_node->intrs[0].line, ya_node->intrs[1].line);
				}
				if (strcasecmp(ya_node->name, "ata4") == 0) {
					if (ya_node->n_intrs < 2) {
						ya_node->intrs = &gatwick_int_pool[count];
						count += 2;
					}
					ya_node->n_intrs = 2;
					ya_node->intrs[0].line = 14+irq_base;
					ya_node->intrs[1].line =  3+irq_base;
					printk(KERN_INFO "irq: fixed ide on second controller (%d,%d)\n",
						ya_node->intrs[0].line, ya_node->intrs[1].line);
				}
				ya_node = ya_node->sibling;
			}
		}
		node = node->sibling;
	}
	if (count > 10) {
		printk("WARNING !! Gatwick interrupt pool overflow\n");
		printk("  GATWICK_IRQ_POOL_SIZE = %d\n", GATWICK_IRQ_POOL_SIZE);
		printk("              requested = %d\n", count);
	}
}

/*
 * The PowerBook 3400/2400/3500 can have a combo ethernet/modem
 * card which includes an ohare chip that acts as a second interrupt
 * controller.  If we find this second ohare, set it up and fix the
 * interrupt value in the device tree for the ethernet chip.
 */
static int __init enable_second_ohare(void)
{
	unsigned char bus, devfn;
	unsigned short cmd;
        unsigned long addr;
	struct device_node *irqctrler = find_devices("pci106b,7");
	struct device_node *ether;

	if (irqctrler == NULL || irqctrler->n_addrs <= 0)
		return -1;
	addr = (unsigned long) ioremap(irqctrler->addrs[0].address, 0x40);
	pmac_irq_hw[1] = (volatile struct pmac_irq_hw *)(addr + 0x20);
	max_irqs = 64;
	if (pci_device_from_OF_node(irqctrler, &bus, &devfn) == 0) {
		struct pci_controller* hose = pci_find_hose_for_OF_device(irqctrler);
		if (!hose)
		    printk(KERN_ERR "Can't find PCI hose for OHare2 !\n");
		else {
		    early_read_config_word(hose, bus, devfn, PCI_COMMAND, &cmd);
		    cmd |= PCI_COMMAND_MEMORY | PCI_COMMAND_MASTER;
	  	    cmd &= ~PCI_COMMAND_IO;
		    early_write_config_word(hose, bus, devfn, PCI_COMMAND, cmd);
		}
	}

	/* Fix interrupt for the modem/ethernet combo controller. The number
	   in the device tree (27) is bogus (correct for the ethernet-only
	   board but not the combo ethernet/modem board).
	   The real interrupt is 28 on the second controller -> 28+32 = 60.
	*/
	ether = find_devices("pci1011,14");
	if (ether && ether->n_intrs > 0) {
		ether->intrs[0].line = 60;
		printk(KERN_INFO "irq: Fixed ethernet IRQ to %d\n",
		       ether->intrs[0].line);
	}

	/* Return the interrupt number of the cascade */
	return irqctrler->intrs[0].line;
}

#ifdef CONFIG_POWER4
static irqreturn_t k2u3_action(int cpl, void *dev_id, struct pt_regs *regs)
{
	int irq;

	irq = openpic2_get_irq(regs);
	if (irq != -1)
		__do_IRQ(irq, regs);
	return IRQ_HANDLED;
}

static struct irqaction k2u3_cascade_action = {
	.handler	= k2u3_action,
	.flags		= 0,
	.mask		= CPU_MASK_NONE,
	.name		= "U3->K2 Cascade",
};
#endif /* CONFIG_POWER4 */

#ifdef CONFIG_XMON
static struct irqaction xmon_action = {
	.handler	= xmon_irq,
	.flags		= 0,
	.mask		= CPU_MASK_NONE,
	.name		= "NMI - XMON"
};
#endif

static struct irqaction gatwick_cascade_action = {
	.handler	= gatwick_action,
	.flags		= SA_INTERRUPT,
	.mask		= CPU_MASK_NONE,
	.name		= "cascade",
};

void __init pmac_pic_init(void)
{
        int i;
        struct device_node *irqctrler  = NULL;
        struct device_node *irqctrler2 = NULL;
	struct device_node *np;
        unsigned long addr;
	int irq_cascade = -1;

	/* We first try to detect Apple's new Core99 chipset, since mac-io
	 * is quite different on those machines and contains an IBM MPIC2.
	 */
	np = find_type_devices("open-pic");
	while(np) {
		if (np->parent && !strcmp(np->parent->name, "u3"))
			irqctrler2 = np;
		else
			irqctrler = np;
		np = np->next;
	}
	if (irqctrler != NULL)
	{
		if (irqctrler->n_addrs > 0)
		{
			unsigned char senses[128];

			printk(KERN_INFO "PowerMac using OpenPIC irq controller at 0x%08x\n",
			       irqctrler->addrs[0].address);

			prom_get_irq_senses(senses, 0, 128);
			OpenPIC_InitSenses = senses;
			OpenPIC_NumInitSenses = 128;
			ppc_md.get_irq = openpic_get_irq;
			pmac_call_feature(PMAC_FTR_ENABLE_MPIC, irqctrler, 0, 0);
			OpenPIC_Addr = ioremap(irqctrler->addrs[0].address,
					       irqctrler->addrs[0].size);
			openpic_init(0);

#ifdef CONFIG_POWER4
			if (irqctrler2 != NULL && irqctrler2->n_intrs > 0 &&
			    irqctrler2->n_addrs > 0) {
				printk(KERN_INFO "Slave OpenPIC at 0x%08x hooked on IRQ %d\n",
				       irqctrler2->addrs[0].address,
				       irqctrler2->intrs[0].line);
				pmac_call_feature(PMAC_FTR_ENABLE_MPIC, irqctrler2, 0, 0);
				OpenPIC2_Addr = ioremap(irqctrler2->addrs[0].address,
							irqctrler2->addrs[0].size);
				prom_get_irq_senses(senses, PMAC_OPENPIC2_OFFSET,
						    PMAC_OPENPIC2_OFFSET+128);
				OpenPIC_InitSenses = senses;
				OpenPIC_NumInitSenses = 128;
				openpic2_init(PMAC_OPENPIC2_OFFSET);

				if (setup_irq(irqctrler2->intrs[0].line,
					      &k2u3_cascade_action))
					printk("Unable to get OpenPIC IRQ for cascade\n");
			}
#endif /* CONFIG_POWER4 */

#ifdef CONFIG_XMON
			{
				struct device_node* pswitch;
				int nmi_irq;

				pswitch = find_devices("programmer-switch");
				if (pswitch && pswitch->n_intrs) {
					nmi_irq = pswitch->intrs[0].line;
					openpic_init_nmi_irq(nmi_irq);
					setup_irq(nmi_irq, &xmon_action);
				}
			}
#endif	/* CONFIG_XMON */
			return;
		}
		irqctrler = NULL;
	}

	/* Get the level/edge settings, assume if it's not
	 * a Grand Central nor an OHare, then it's an Heathrow
	 * (or Paddington).
	 */
	if (find_devices("gc"))
		level_mask[0] = GC_LEVEL_MASK;
	else if (find_devices("ohare")) {
		level_mask[0] = OHARE_LEVEL_MASK;
		/* We might have a second cascaded ohare */
		level_mask[1] = OHARE_LEVEL_MASK;
	} else {
		level_mask[0] = HEATHROW_LEVEL_MASK;
		level_mask[1] = 0;
		/* We might have a second cascaded heathrow */
		level_mask[2] = HEATHROW_LEVEL_MASK;
		level_mask[3] = 0;
	}

	/*
	 * G3 powermacs and 1999 G3 PowerBooks have 64 interrupts,
	 * 1998 G3 Series PowerBooks have 128,
	 * other powermacs have 32.
	 * The combo ethernet/modem card for the Powerstar powerbooks
	 * (2400/3400/3500, ohare based) has a second ohare chip
	 * effectively making a total of 64.
	 */
	max_irqs = max_real_irqs = 32;
	irqctrler = find_devices("mac-io");
	if (irqctrler)
	{
		max_real_irqs = 64;
		if (irqctrler->next)
			max_irqs = 128;
		else
			max_irqs = 64;
	}
	for ( i = 0; i < max_real_irqs ; i++ )
		irq_desc[i].handler = &pmac_pic;

	/* get addresses of first controller */
	if (irqctrler) {
		if  (irqctrler->n_addrs > 0) {
			addr = (unsigned long)
				ioremap(irqctrler->addrs[0].address, 0x40);
			for (i = 0; i < 2; ++i)
				pmac_irq_hw[i] = (volatile struct pmac_irq_hw*)
					(addr + (2 - i) * 0x10);
		}

		/* get addresses of second controller */
		irqctrler = irqctrler->next;
		if (irqctrler && irqctrler->n_addrs > 0) {
			addr = (unsigned long)
				ioremap(irqctrler->addrs[0].address, 0x40);
			for (i = 2; i < 4; ++i)
				pmac_irq_hw[i] = (volatile struct pmac_irq_hw*)
					(addr + (4 - i) * 0x10);
			irq_cascade = irqctrler->intrs[0].line;
			if (device_is_compatible(irqctrler, "gatwick"))
				pmac_fix_gatwick_interrupts(irqctrler, max_real_irqs);
		}
	} else {
		/* older powermacs have a GC (grand central) or ohare at
		   f3000000, with interrupt control registers at f3000020. */
		addr = (unsigned long) ioremap(0xf3000000, 0x40);
		pmac_irq_hw[0] = (volatile struct pmac_irq_hw *) (addr + 0x20);
	}

	/* PowerBooks 3400 and 3500 can have a second controller in a second
	   ohare chip, on the combo ethernet/modem card */
	if (machine_is_compatible("AAPL,3400/2400")
	     || machine_is_compatible("AAPL,3500"))
		irq_cascade = enable_second_ohare();

	/* disable all interrupts in all controllers */
	for (i = 0; i * 32 < max_irqs; ++i)
		out_le32(&pmac_irq_hw[i]->enable, 0);
	/* mark level interrupts */
	for (i = 0; i < max_irqs; i++)
		if (level_mask[i >> 5] & (1UL << (i & 0x1f)))
			irq_desc[i].status = IRQ_LEVEL;

	/* get interrupt line of secondary interrupt controller */
	if (irq_cascade >= 0) {
		printk(KERN_INFO "irq: secondary controller on irq %d\n",
			(int)irq_cascade);
		for ( i = max_real_irqs ; i < max_irqs ; i++ )
			irq_desc[i].handler = &gatwick_pic;
		setup_irq(irq_cascade, &gatwick_cascade_action);
	}
	printk("System has %d possible interrupts\n", max_irqs);
	if (max_irqs != max_real_irqs)
		printk(KERN_DEBUG "%d interrupts on main controller\n",
			max_real_irqs);

#ifdef CONFIG_XMON
	setup_irq(20, &xmon_action);
#endif	/* CONFIG_XMON */
}

#ifdef CONFIG_PM
/*
 * These procedures are used in implementing sleep on the powerbooks.
 * sleep_save_intrs() saves the states of all interrupt enables
 * and disables all interrupts except for the nominated one.
 * sleep_restore_intrs() restores the states of all interrupt enables.
 */
unsigned long sleep_save_mask[2];

/* This used to be passed by the PMU driver but that link got
 * broken with the new driver model. We use this tweak for now...
 */
static int pmacpic_find_viaint(void)
{
	int viaint = -1;

#ifdef CONFIG_ADB_PMU
	struct device_node *np;

	if (pmu_get_model() != PMU_OHARE_BASED)
		goto not_found;
	np = of_find_node_by_name(NULL, "via-pmu");
	if (np == NULL)
		goto not_found;
	viaint = np->intrs[0].line;
#endif /* CONFIG_ADB_PMU */

not_found:
	return viaint;
}

static int pmacpic_suspend(struct sys_device *sysdev, u32 state)
{
	int viaint = pmacpic_find_viaint();

	sleep_save_mask[0] = ppc_cached_irq_mask[0];
	sleep_save_mask[1] = ppc_cached_irq_mask[1];
	ppc_cached_irq_mask[0] = 0;
	ppc_cached_irq_mask[1] = 0;
	if (viaint > 0)
		set_bit(viaint, ppc_cached_irq_mask);
	out_le32(&pmac_irq_hw[0]->enable, ppc_cached_irq_mask[0]);
	if (max_real_irqs > 32)
		out_le32(&pmac_irq_hw[1]->enable, ppc_cached_irq_mask[1]);
	(void)in_le32(&pmac_irq_hw[0]->event);
	/* make sure mask gets to controller before we return to caller */
	mb();
        (void)in_le32(&pmac_irq_hw[0]->enable);

        return 0;
}

static int pmacpic_resume(struct sys_device *sysdev)
{
	int i;

	out_le32(&pmac_irq_hw[0]->enable, 0);
	if (max_real_irqs > 32)
		out_le32(&pmac_irq_hw[1]->enable, 0);
	mb();
	for (i = 0; i < max_real_irqs; ++i)
		if (test_bit(i, sleep_save_mask))
			pmac_unmask_irq(i);

	return 0;
}

#endif /* CONFIG_PM */

static struct sysdev_class pmacpic_sysclass = {
	set_kset_name("pmac_pic"),
};

static struct sys_device device_pmacpic = {
	.id		= 0,
	.cls		= &pmacpic_sysclass,
};

static struct sysdev_driver driver_pmacpic = {
#ifdef CONFIG_PM
	.suspend	= &pmacpic_suspend,
	.resume		= &pmacpic_resume,
#endif /* CONFIG_PM */
};

static int __init init_pmacpic_sysfs(void)
{
	if (max_irqs == 0)
		return -ENODEV;

	printk(KERN_DEBUG "Registering pmac pic with sysfs...\n");
	sysdev_class_register(&pmacpic_sysclass);
	sysdev_register(&device_pmacpic);
	sysdev_driver_register(&pmacpic_sysclass, &driver_pmacpic);
	return 0;
}

subsys_initcall(init_pmacpic_sysfs);