/*
 *  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@samba.org)
 *  Copyright (C) 2005 Benjamin Herrenschmidt (benh@kernel.crashing.org)
 *                     IBM, Corp.
 *
 *  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/stddef.h>
#include <linux/init.h>
#include <linux/sched.h>
#include <linux/signal.h>
#include <linux/pci.h>
#include <linux/interrupt.h>
#include <linux/syscore_ops.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/pmac_feature.h>
#include <asm/mpic.h>
#include <asm/xmon.h>

#include "pmac.h"

#ifdef CONFIG_PPC32
struct pmac_irq_hw {
        unsigned int    event;
        unsigned int    enable;
        unsigned int    ack;
        unsigned int    level;
};

/* Workaround flags for 32bit powermac machines */
unsigned int of_irq_workarounds;
struct device_node *of_irq_dflt_pic;

/* Default addresses */
static volatile struct pmac_irq_hw __iomem *pmac_irq_hw[4];

static int max_irqs;
static int max_real_irqs;

static DEFINE_RAW_SPINLOCK(pmac_pic_lock);

/* The max irq number this driver deals with is 128; see max_irqs */
static DECLARE_BITMAP(ppc_lost_interrupts, 128);
static DECLARE_BITMAP(ppc_cached_irq_mask, 128);
static int pmac_irq_cascade = -1;
static struct irq_domain *pmac_pic_host;

static void __pmac_retrigger(unsigned int irq_nr)
{
        if (irq_nr >= max_real_irqs && pmac_irq_cascade > 0) {
                __set_bit(irq_nr, ppc_lost_interrupts);
                irq_nr = pmac_irq_cascade;
                mb();
        }
        if (!__test_and_set_bit(irq_nr, ppc_lost_interrupts)) {
                atomic_inc(&ppc_n_lost_interrupts);
                set_dec(1);
        }
}

static void pmac_mask_and_ack_irq(struct irq_data *d)
{
        unsigned int src = irqd_to_hwirq(d);
        unsigned long bit = 1UL << (src & 0x1f);
        int i = src >> 5;
        unsigned long flags;

        raw_spin_lock_irqsave(&pmac_pic_lock, flags);
        __clear_bit(src, ppc_cached_irq_mask);
        if (__test_and_clear_bit(src, ppc_lost_interrupts))
                atomic_dec(&ppc_n_lost_interrupts);
        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));
        raw_spin_unlock_irqrestore(&pmac_pic_lock, flags);
}

static void pmac_ack_irq(struct irq_data *d)
{
        unsigned int src = irqd_to_hwirq(d);
        unsigned long bit = 1UL << (src & 0x1f);
        int i = src >> 5;
        unsigned long flags;

        raw_spin_lock_irqsave(&pmac_pic_lock, flags);
        if (__test_and_clear_bit(src, ppc_lost_interrupts))
                atomic_dec(&ppc_n_lost_interrupts);
        out_le32(&pmac_irq_hw[i]->ack, bit);
        (void)in_le32(&pmac_irq_hw[i]->ack);
        raw_spin_unlock_irqrestore(&pmac_pic_lock, flags);
}

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

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

        /* 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))
                __pmac_retrigger(irq_nr);
}

/* 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_startup_irq(struct irq_data *d)
{
        unsigned long flags;
        unsigned int src = irqd_to_hwirq(d);
        unsigned long bit = 1UL << (src & 0x1f);
        int i = src >> 5;

        raw_spin_lock_irqsave(&pmac_pic_lock, flags);
        if (!irqd_is_level_type(d))
                out_le32(&pmac_irq_hw[i]->ack, bit);
        __set_bit(src, ppc_cached_irq_mask);
        __pmac_set_irq_mask(src, 0);
        raw_spin_unlock_irqrestore(&pmac_pic_lock, flags);

        return 0;
}

static void pmac_mask_irq(struct irq_data *d)
{
        unsigned long flags;
        unsigned int src = irqd_to_hwirq(d);

        raw_spin_lock_irqsave(&pmac_pic_lock, flags);
        __clear_bit(src, ppc_cached_irq_mask);
        __pmac_set_irq_mask(src, 1);
        raw_spin_unlock_irqrestore(&pmac_pic_lock, flags);
}

static void pmac_unmask_irq(struct irq_data *d)
{
        unsigned long flags;
        unsigned int src = irqd_to_hwirq(d);

        raw_spin_lock_irqsave(&pmac_pic_lock, flags);
        __set_bit(src, ppc_cached_irq_mask);
        __pmac_set_irq_mask(src, 0);
        raw_spin_unlock_irqrestore(&pmac_pic_lock, flags);
}

static int pmac_retrigger(struct irq_data *d)
{
        unsigned long flags;

        raw_spin_lock_irqsave(&pmac_pic_lock, flags);
        __pmac_retrigger(irqd_to_hwirq(d));
        raw_spin_unlock_irqrestore(&pmac_pic_lock, flags);
        return 1;
}

static struct irq_chip pmac_pic = {
        .name           = "PMAC-PIC",
        .irq_startup    = pmac_startup_irq,
        .irq_mask       = pmac_mask_irq,
        .irq_ack        = pmac_ack_irq,
        .irq_mask_ack   = pmac_mask_and_ack_irq,
        .irq_unmask     = pmac_unmask_irq,
        .irq_retrigger  = pmac_retrigger,
};

static irqreturn_t gatwick_action(int cpl, void *dev_id)
{
        unsigned long flags;
        int irq, bits;
        int rc = IRQ_NONE;

        raw_spin_lock_irqsave(&pmac_pic_lock, flags);
        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];
                bits |= in_le32(&pmac_irq_hw[i]->level);
                bits &= ppc_cached_irq_mask[i];
                if (bits == 0)
                        continue;
                irq += __ilog2(bits);
                raw_spin_unlock_irqrestore(&pmac_pic_lock, flags);
                generic_handle_irq(irq);
                raw_spin_lock_irqsave(&pmac_pic_lock, flags);
                rc = IRQ_HANDLED;
        }
        raw_spin_unlock_irqrestore(&pmac_pic_lock, flags);
        return rc;
}

static unsigned int pmac_pic_get_irq(void)
{
        int irq;
        unsigned long bits = 0;
        unsigned long flags;

#ifdef CONFIG_PPC_PMAC32_PSURGE
        /* IPI's are a hack on the powersurge -- Cort */
        if (smp_processor_id() != 0) {
                return  psurge_secondary_virq;
        }
#endif /* CONFIG_PPC_PMAC32_PSURGE */
        raw_spin_lock_irqsave(&pmac_pic_lock, flags);
        for (irq = max_real_irqs; (irq -= 32) >= 0; ) {
                int i = irq >> 5;
                bits = in_le32(&pmac_irq_hw[i]->event) | ppc_lost_interrupts[i];
                bits |= in_le32(&pmac_irq_hw[i]->level);
                bits &= ppc_cached_irq_mask[i];
                if (bits == 0)
                        continue;
                irq += __ilog2(bits);
                break;
        }
        raw_spin_unlock_irqrestore(&pmac_pic_lock, flags);
        if (unlikely(irq < 0))
                return 0;
        return irq_linear_revmap(pmac_pic_host, irq);
}

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

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

static int pmac_pic_host_match(struct irq_domain *h, struct device_node *node,
                               enum irq_domain_bus_token bus_token)
{
        /* We match all, we don't always have a node anyway */
        return 1;
}

static int pmac_pic_host_map(struct irq_domain *h, unsigned int virq,
                             irq_hw_number_t hw)
{
        if (hw >= max_irqs)
                return -EINVAL;

        /* Mark level interrupts, set delayed disable for edge ones and set
         * handlers
         */
        irq_set_status_flags(virq, IRQ_LEVEL);
        irq_set_chip_and_handler(virq, &pmac_pic, handle_level_irq);
        return 0;
}

static const struct irq_domain_ops pmac_pic_host_ops = {
        .match = pmac_pic_host_match,
        .map = pmac_pic_host_map,
        .xlate = irq_domain_xlate_onecell,
};

static void __init pmac_pic_probe_oldstyle(void)
{
        int i;
        struct device_node *master = NULL;
        struct device_node *slave = NULL;
        u8 __iomem *addr;
        struct resource r;

        /* Set our get_irq function */
        ppc_md.get_irq = pmac_pic_get_irq;

        /*
         * Find the interrupt controller type & node
         */

        if ((master = of_find_node_by_name(NULL, "gc")) != NULL) {
                max_irqs = max_real_irqs = 32;
        } else if ((master = of_find_node_by_name(NULL, "ohare")) != NULL) {
                max_irqs = max_real_irqs = 32;
                /* We might have a second cascaded ohare */
                slave = of_find_node_by_name(NULL, "pci106b,7");
                if (slave)
                        max_irqs = 64;
        } else if ((master = of_find_node_by_name(NULL, "mac-io")) != NULL) {
                max_irqs = max_real_irqs = 64;

                /* We might have a second cascaded heathrow */

                /* Compensate for of_node_put() in of_find_node_by_name() */
                of_node_get(master);
                slave = of_find_node_by_name(master, "mac-io");

                /* Check ordering of master & slave */
                if (of_device_is_compatible(master, "gatwick")) {
                        struct device_node *tmp;
                        BUG_ON(slave == NULL);
                        tmp = master;
                        master = slave;
                        slave = tmp;
                }

                /* We found a slave */
                if (slave)
                        max_irqs = 128;
        }
        BUG_ON(master == NULL);

        /*
         * Allocate an irq host
         */
        pmac_pic_host = irq_domain_add_linear(master, max_irqs,
                                              &pmac_pic_host_ops, NULL);
        BUG_ON(pmac_pic_host == NULL);
        irq_set_default_host(pmac_pic_host);

        /* Get addresses of first controller if we have a node for it */
        BUG_ON(of_address_to_resource(master, 0, &r));

        /* Map interrupts of primary controller */
        addr = (u8 __iomem *) ioremap(r.start, 0x40);
        i = 0;
        pmac_irq_hw[i++] = (volatile struct pmac_irq_hw __iomem *)
                (addr + 0x20);
        if (max_real_irqs > 32)
                pmac_irq_hw[i++] = (volatile struct pmac_irq_hw __iomem *)
                        (addr + 0x10);
        of_node_put(master);

        printk(KERN_INFO "irq: Found primary Apple PIC %s for %d irqs\n",
               master->full_name, max_real_irqs);

        /* Map interrupts of cascaded controller */
        if (slave && !of_address_to_resource(slave, 0, &r)) {
                addr = (u8 __iomem *)ioremap(r.start, 0x40);
                pmac_irq_hw[i++] = (volatile struct pmac_irq_hw __iomem *)
                        (addr + 0x20);
                if (max_irqs > 64)
                        pmac_irq_hw[i++] =
                                (volatile struct pmac_irq_hw __iomem *)
                                (addr + 0x10);
                pmac_irq_cascade = irq_of_parse_and_map(slave, 0);

                printk(KERN_INFO "irq: Found slave Apple PIC %s for %d irqs"
                       " cascade: %d\n", slave->full_name,
                       max_irqs - max_real_irqs, pmac_irq_cascade);
        }
        of_node_put(slave);

        /* Disable all interrupts in all controllers */
        for (i = 0; i * 32 < max_irqs; ++i)
                out_le32(&pmac_irq_hw[i]->enable, 0);

        /* Hookup cascade irq */
        if (slave && pmac_irq_cascade)
                setup_irq(pmac_irq_cascade, &gatwick_cascade_action);

        printk(KERN_INFO "irq: System has %d possible interrupts\n", max_irqs);
#ifdef CONFIG_XMON
        setup_irq(irq_create_mapping(NULL, 20), &xmon_action);
#endif
}

int of_irq_parse_oldworld(struct device_node *device, int index,
                        struct of_phandle_args *out_irq)
{
        const u32 *ints = NULL;
        int intlen;

        /*
         * Old machines just have a list of interrupt numbers
         * and no interrupt-controller nodes. We also have dodgy
         * cases where the APPL,interrupts property is completely
         * missing behind pci-pci bridges and we have to get it
         * from the parent (the bridge itself, as apple just wired
         * everything together on these)
         */
        while (device) {
                ints = of_get_property(device, "AAPL,interrupts", &intlen);
                if (ints != NULL)
                        break;
                device = device->parent;
                if (device && strcmp(device->type, "pci") != 0)
                        break;
        }
        if (ints == NULL)
                return -EINVAL;
        intlen /= sizeof(u32);

        if (index >= intlen)
                return -EINVAL;

        out_irq->np = NULL;
        out_irq->args[0] = ints[index];
        out_irq->args_count = 1;

        return 0;
}
#endif /* CONFIG_PPC32 */

static void __init pmac_pic_setup_mpic_nmi(struct mpic *mpic)
{
#if defined(CONFIG_XMON) && defined(CONFIG_PPC32)
        struct device_node* pswitch;
        int nmi_irq;

        pswitch = of_find_node_by_name(NULL, "programmer-switch");
        if (pswitch) {
                nmi_irq = irq_of_parse_and_map(pswitch, 0);
                if (nmi_irq) {
                        mpic_irq_set_priority(nmi_irq, 9);
                        setup_irq(nmi_irq, &xmon_action);
                }
                of_node_put(pswitch);
        }
#endif  /* defined(CONFIG_XMON) && defined(CONFIG_PPC32) */
}

static struct mpic * __init pmac_setup_one_mpic(struct device_node *np,
                                                int master)
{
        const char *name = master ? " MPIC 1   " : " MPIC 2   ";
        struct mpic *mpic;
        unsigned int flags = master ? 0 : MPIC_SECONDARY;

        pmac_call_feature(PMAC_FTR_ENABLE_MPIC, np, 0, 0);

        if (of_get_property(np, "big-endian", NULL))
                flags |= MPIC_BIG_ENDIAN;

        /* Primary Big Endian means HT interrupts. This is quite dodgy
         * but works until I find a better way
         */
        if (master && (flags & MPIC_BIG_ENDIAN))
                flags |= MPIC_U3_HT_IRQS;

        mpic = mpic_alloc(np, 0, flags, 0, 0, name);
        if (mpic == NULL)
                return NULL;

        mpic_init(mpic);

        return mpic;
 }

static int __init pmac_pic_probe_mpic(void)
{
        struct mpic *mpic1, *mpic2;
        struct device_node *np, *master = NULL, *slave = NULL;

        /* We can have up to 2 MPICs cascaded */
        for (np = NULL; (np = of_find_node_by_type(np, "open-pic"))
                     != NULL;) {
                if (master == NULL &&
                    of_get_property(np, "interrupts", NULL) == NULL)
                        master = of_node_get(np);
                else if (slave == NULL)
                        slave = of_node_get(np);
                if (master && slave)
                        break;
        }

        /* Check for bogus setups */
        if (master == NULL && slave != NULL) {
                master = slave;
                slave = NULL;
        }

        /* Not found, default to good old pmac pic */
        if (master == NULL)
                return -ENODEV;

        /* Set master handler */
        ppc_md.get_irq = mpic_get_irq;

        /* Setup master */
        mpic1 = pmac_setup_one_mpic(master, 1);
        BUG_ON(mpic1 == NULL);

        /* Install NMI if any */
        pmac_pic_setup_mpic_nmi(mpic1);

        of_node_put(master);

        /* Set up a cascaded controller, if present */
        if (slave) {
                mpic2 = pmac_setup_one_mpic(slave, 0);
                if (mpic2 == NULL)
                        printk(KERN_ERR "Failed to setup slave MPIC\n");
                of_node_put(slave);
        }

        return 0;
}


void __init pmac_pic_init(void)
{
        /* We configure the OF parsing based on our oldworld vs. newworld
         * platform type and whether we were booted by BootX.
         */
#ifdef CONFIG_PPC32
        if (!pmac_newworld)
                of_irq_workarounds |= OF_IMAP_OLDWORLD_MAC;
        if (of_get_property(of_chosen, "linux,bootx", NULL) != NULL)
                of_irq_workarounds |= OF_IMAP_NO_PHANDLE;

        /* If we don't have phandles on a newworld, then try to locate a
         * default interrupt controller (happens when booting with BootX).
         * We do a first match here, hopefully, that only ever happens on
         * machines with one controller.
         */
        if (pmac_newworld && (of_irq_workarounds & OF_IMAP_NO_PHANDLE)) {
                struct device_node *np;

                for_each_node_with_property(np, "interrupt-controller") {
                        /* Skip /chosen/interrupt-controller */
                        if (strcmp(np->name, "chosen") == 0)
                                continue;
                        /* It seems like at least one person wants
                         * to use BootX on a machine with an AppleKiwi
                         * controller which happens to pretend to be an
                         * interrupt controller too. */
                        if (strcmp(np->name, "AppleKiwi") == 0)
                                continue;
                        /* I think we found one ! */
                        of_irq_dflt_pic = np;
                        break;
                }
        }
#endif /* CONFIG_PPC32 */

        /* We first try to detect Apple's new Core99 chipset, since mac-io
         * is quite different on those machines and contains an IBM MPIC2.
         */
        if (pmac_pic_probe_mpic() == 0)
                return;

#ifdef CONFIG_PPC32
        pmac_pic_probe_oldstyle();
#endif
}

#if defined(CONFIG_PM) && defined(CONFIG_PPC32)
/*
 * 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...
 * We really want to do things differently though...
 */
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 = irq_of_parse_and_map(np, 0);

not_found:
#endif /* CONFIG_ADB_PMU */
        return viaint;
}

static int pmacpic_suspend(void)
{
        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 void pmacpic_resume(void)
{
        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(irq_get_irq_data(i));
}

static struct syscore_ops pmacpic_syscore_ops = {
        .suspend        = pmacpic_suspend,
        .resume         = pmacpic_resume,
};

static int __init init_pmacpic_syscore(void)
{
        if (pmac_irq_hw[0])
                register_syscore_ops(&pmacpic_syscore_ops);
        return 0;
}

machine_subsys_initcall(powermac, init_pmacpic_syscore);

#endif /* CONFIG_PM && CONFIG_PPC32 */