/*

 * SuperH interrupt controller module

 *

 * Copyright (c) 2007 Magnus Damm

 * Based on sh_timer.c and arm_timer.c by Paul Brook

 * Copyright (c) 2005-2006 CodeSourcery.

 *

 * This code is licenced under the GPL.

 */

#include <assert.h>

#include "sh_intc.h"

#include "hw.h"

#include "sh.h"

//#define DEBUG_INTC

//#define DEBUG_INTC_SOURCES

#define INTC_A7(x) ((x) & 0x1fffffff)

void sh_intc_toggle_source(struct intc_source *source,

			   int enable_adj, int assert_adj)

{

    int enable_changed = 0;

    int pending_changed = 0;

    int old_pending;

    if ((source->enable_count == source->enable_max) && (enable_adj == -1))

        enable_changed = -1;

    source->enable_count += enable_adj;

    if (source->enable_count == source->enable_max)

        enable_changed = 1;

    source->asserted += assert_adj;

    old_pending = source->pending;

    source->pending = source->asserted &&

      (source->enable_count == source->enable_max);

    if (old_pending != source->pending)

        pending_changed = 1;

    if (pending_changed) {

        if (source->pending) {

            source->parent->pending++;

	    if (source->parent->pending == 1)

                cpu_interrupt(first_cpu, CPU_INTERRUPT_HARD);

	}

	else {

            source->parent->pending--;

	    if (source->parent->pending == 0)

                cpu_reset_interrupt(first_cpu, CPU_INTERRUPT_HARD);

	}

    }

  if (enable_changed || assert_adj || pending_changed) {

#ifdef DEBUG_INTC_SOURCES

            printf("sh_intc: (%d/%d/%d/%d) interrupt source 0x%x %s%s%s\n",

		   source->parent->pending,

		   source->asserted,

		   source->enable_count,

		   source->enable_max,

		   source->vect,

		   source->asserted ? "asserted " :

		   assert_adj ? "deasserted" : "",

		   enable_changed == 1 ? "enabled " :

		   enable_changed == -1 ? "disabled " : "",

		   source->pending ? "pending" : "");

#endif

  }

}

static void sh_intc_set_irq (void *opaque, int n, int level)

{

  struct intc_desc *desc = opaque;

  struct intc_source *source = &(desc->sources[n]);

  if (level && !source->asserted)

    sh_intc_toggle_source(source, 0, 1);

  else if (!level && source->asserted)

    sh_intc_toggle_source(source, 0, -1);

}

int sh_intc_get_pending_vector(struct intc_desc *desc, int imask)

{

    unsigned int i;

    /* slow: use a linked lists of pending sources instead */

    /* wrong: take interrupt priority into account (one list per priority) */

    if (imask == 0x0f) {

        return -1; /* FIXME, update code to include priority per source */

    }

    for (i = 0; i < desc->nr_sources; i++) {

        struct intc_source *source = desc->sources + i;

	if (source->pending) {

#ifdef DEBUG_INTC_SOURCES

            printf("sh_intc: (%d) returning interrupt source 0x%x\n",

		   desc->pending, source->vect);

#endif

            return source->vect;

	}

    }

    assert(0);

}

#define INTC_MODE_NONE       0

#define INTC_MODE_DUAL_SET   1

#define INTC_MODE_DUAL_CLR   2

#define INTC_MODE_ENABLE_REG 3

#define INTC_MODE_MASK_REG   4

#define INTC_MODE_IS_PRIO    8

static unsigned int sh_intc_mode(unsigned long address,

				 unsigned long set_reg, unsigned long clr_reg)

{

    if ((address != INTC_A7(set_reg)) &&

	(address != INTC_A7(clr_reg)))

        return INTC_MODE_NONE;

    if (set_reg && clr_reg) {

        if (address == INTC_A7(set_reg))

            return INTC_MODE_DUAL_SET;

	else

            return INTC_MODE_DUAL_CLR;

    }

    if (set_reg)

        return INTC_MODE_ENABLE_REG;

    else

        return INTC_MODE_MASK_REG;

}

static void sh_intc_locate(struct intc_desc *desc,

			   unsigned long address,

			   unsigned long **datap,

			   intc_enum **enums,

			   unsigned int *first,

			   unsigned int *width,

			   unsigned int *modep)

{

    unsigned int i, mode;

    /* this is slow but works for now */

    if (desc->mask_regs) {

        for (i = 0; i < desc->nr_mask_regs; i++) {

	    struct intc_mask_reg *mr = desc->mask_regs + i;

	    mode = sh_intc_mode(address, mr->set_reg, mr->clr_reg);

	    if (mode == INTC_MODE_NONE)

                continue;

	    *modep = mode;

	    *datap = &mr->value;

	    *enums = mr->enum_ids;

	    *first = mr->reg_width - 1;

	    *width = 1;

	    return;

	}

    }

    if (desc->prio_regs) {

        for (i = 0; i < desc->nr_prio_regs; i++) {

	    struct intc_prio_reg *pr = desc->prio_regs + i;

	    mode = sh_intc_mode(address, pr->set_reg, pr->clr_reg);

	    if (mode == INTC_MODE_NONE)

                continue;

	    *modep = mode | INTC_MODE_IS_PRIO;

	    *datap = &pr->value;

	    *enums = pr->enum_ids;

	    *first = (pr->reg_width / pr->field_width) - 1;

	    *width = pr->field_width;

	    return;

	}

    }

    assert(0);

}

static void sh_intc_toggle_mask(struct intc_desc *desc, intc_enum id,

				int enable, int is_group)

{

    struct intc_source *source = desc->sources + id;

    if (!id)

	return;

    if (!source->next_enum_id && (!source->enable_max || !source->vect)) {

#ifdef DEBUG_INTC_SOURCES

        printf("sh_intc: reserved interrupt source %d modified\n", id);

#endif

	return;

    }

    if (source->vect)

        sh_intc_toggle_source(source, enable ? 1 : -1, 0);

#ifdef DEBUG_INTC

    else {

        printf("setting interrupt group %d to %d\n", id, !!enable);

    }

#endif

    if ((is_group || !source->vect) && source->next_enum_id) {

        sh_intc_toggle_mask(desc, source->next_enum_id, enable, 1);

    }

#ifdef DEBUG_INTC

    if (!source->vect) {

        printf("setting interrupt group %d to %d - done\n", id, !!enable);

    }

#endif

}

static uint32_t sh_intc_read(void *opaque, target_phys_addr_t offset)

{

    struct intc_desc *desc = opaque;

    intc_enum *enum_ids = NULL;

    unsigned int first = 0;

    unsigned int width = 0;

    unsigned int mode = 0;

    unsigned long *valuep;

#ifdef DEBUG_INTC

    printf("sh_intc_read 0x%lx\n", (unsigned long) offset);

#endif

    sh_intc_locate(desc, (unsigned long)offset, &valuep, 

		   &enum_ids, &first, &width, &mode);

    return *valuep;

}

static void sh_intc_write(void *opaque, target_phys_addr_t offset,

			  uint32_t value)

{

    struct intc_desc *desc = opaque;

    intc_enum *enum_ids = NULL;

    unsigned int first = 0;

    unsigned int width = 0;

    unsigned int mode = 0;

    unsigned int k;

    unsigned long *valuep;

    unsigned long mask;

#ifdef DEBUG_INTC

    printf("sh_intc_write 0x%lx 0x%08x\n", (unsigned long) offset, value);

#endif

    sh_intc_locate(desc, (unsigned long)offset, &valuep, 

		   &enum_ids, &first, &width, &mode);

    switch (mode) {

    case INTC_MODE_ENABLE_REG | INTC_MODE_IS_PRIO: break;

    case INTC_MODE_DUAL_SET: value |= *valuep; break;

    case INTC_MODE_DUAL_CLR: value = *valuep & ~value; break;

    default: assert(0);

    }

    for (k = 0; k <= first; k++) {

        mask = ((1 << width) - 1) << ((first - k) * width);

	if ((*valuep & mask) == (value & mask))

            continue;

#if 0

	printf("k = %d, first = %d, enum = %d, mask = 0x%08x\n", 

	       k, first, enum_ids[k], (unsigned int)mask);

#endif

        sh_intc_toggle_mask(desc, enum_ids[k], value & mask, 0);

    }

    *valuep = value;

#ifdef DEBUG_INTC

    printf("sh_intc_write 0x%lx -> 0x%08x\n", (unsigned long) offset, value);

#endif

}

static CPUReadMemoryFunc *sh_intc_readfn[] = {

    sh_intc_read,

    sh_intc_read,

    sh_intc_read

};

static CPUWriteMemoryFunc *sh_intc_writefn[] = {

    sh_intc_write,

    sh_intc_write,

    sh_intc_write

};

struct intc_source *sh_intc_source(struct intc_desc *desc, intc_enum id)

{

    if (id)

        return desc->sources + id;

    return NULL;

}

static void sh_intc_register(struct intc_desc *desc, 

			     unsigned long address)

{

    if (address) {

        cpu_register_physical_memory_offset(P4ADDR(address), 4,

                                            desc->iomemtype, INTC_A7(address));

        cpu_register_physical_memory_offset(A7ADDR(address), 4,

                                            desc->iomemtype, INTC_A7(address));

    }

}

static void sh_intc_register_source(struct intc_desc *desc,

				    intc_enum source,

				    struct intc_group *groups,

				    int nr_groups)

{

    unsigned int i, k;

    struct intc_source *s;

    if (desc->mask_regs) {

        for (i = 0; i < desc->nr_mask_regs; i++) {

	    struct intc_mask_reg *mr = desc->mask_regs + i;

	    for (k = 0; k < ARRAY_SIZE(mr->enum_ids); k++) {

                if (mr->enum_ids[k] != source)

                    continue;

		s = sh_intc_source(desc, mr->enum_ids[k]);

		if (s)

                    s->enable_max++;

	    }

	}

    }

    if (desc->prio_regs) {

        for (i = 0; i < desc->nr_prio_regs; i++) {

	    struct intc_prio_reg *pr = desc->prio_regs + i;

	    for (k = 0; k < ARRAY_SIZE(pr->enum_ids); k++) {

                if (pr->enum_ids[k] != source)

                    continue;

		s = sh_intc_source(desc, pr->enum_ids[k]);

		if (s)

                    s->enable_max++;

	    }

	}

    }

    if (groups) {

        for (i = 0; i < nr_groups; i++) {

	    struct intc_group *gr = groups + i;

	    for (k = 0; k < ARRAY_SIZE(gr->enum_ids); k++) {

                if (gr->enum_ids[k] != source)

                    continue;

		s = sh_intc_source(desc, gr->enum_ids[k]);

		if (s)

                    s->enable_max++;

	    }

	}

    }

}

void sh_intc_register_sources(struct intc_desc *desc,

			      struct intc_vect *vectors,

			      int nr_vectors,

			      struct intc_group *groups,

			      int nr_groups)

{

    unsigned int i, k;

    struct intc_source *s;

    for (i = 0; i < nr_vectors; i++) {

	struct intc_vect *vect = vectors + i;

	sh_intc_register_source(desc, vect->enum_id, groups, nr_groups);

	s = sh_intc_source(desc, vect->enum_id);

	if (s)

	    s->vect = vect->vect;

#ifdef DEBUG_INTC_SOURCES

	printf("sh_intc: registered source %d -> 0x%04x (%d/%d)\n",

	       vect->enum_id, s->vect, s->enable_count, s->enable_max);

#endif

    }

    if (groups) {

        for (i = 0; i < nr_groups; i++) {

	    struct intc_group *gr = groups + i;

	    s = sh_intc_source(desc, gr->enum_id);

	    s->next_enum_id = gr->enum_ids[0];

	    for (k = 1; k < ARRAY_SIZE(gr->enum_ids); k++) {

                if (!gr->enum_ids[k])

                    continue;

		s = sh_intc_source(desc, gr->enum_ids[k - 1]);

		s->next_enum_id = gr->enum_ids[k];

	    }

#ifdef DEBUG_INTC_SOURCES

	    printf("sh_intc: registered group %d (%d/%d)\n",

		   gr->enum_id, s->enable_count, s->enable_max);

#endif

	}

    }

}

int sh_intc_init(struct intc_desc *desc,

		 int nr_sources,

		 struct intc_mask_reg *mask_regs,

		 int nr_mask_regs,

		 struct intc_prio_reg *prio_regs,

		 int nr_prio_regs)

{

    unsigned int i;

    desc->pending = 0;

    desc->nr_sources = nr_sources;

    desc->mask_regs = mask_regs;

    desc->nr_mask_regs = nr_mask_regs;

    desc->prio_regs = prio_regs;

    desc->nr_prio_regs = nr_prio_regs;

    i = sizeof(struct intc_source) * nr_sources;

    desc->sources = malloc(i);

    if (!desc->sources)

        return -1;

    memset(desc->sources, 0, i);

    for (i = 0; i < desc->nr_sources; i++) {

        struct intc_source *source = desc->sources + i;

        source->parent = desc;

    }

    desc->irqs = qemu_allocate_irqs(sh_intc_set_irq, desc, nr_sources);

    desc->iomemtype = cpu_register_io_memory(0, sh_intc_readfn,

					     sh_intc_writefn, desc);

    if (desc->mask_regs) {

        for (i = 0; i < desc->nr_mask_regs; i++) {

	    struct intc_mask_reg *mr = desc->mask_regs + i;

	    sh_intc_register(desc, mr->set_reg);

	    sh_intc_register(desc, mr->clr_reg);

	}

    }

    if (desc->prio_regs) {

        for (i = 0; i < desc->nr_prio_regs; i++) {

	    struct intc_prio_reg *pr = desc->prio_regs + i;

	    sh_intc_register(desc, pr->set_reg);

	    sh_intc_register(desc, pr->clr_reg);

	}

    }

    return 0;

}

/* Assert level <n> IRL interrupt. 

   0:deassert. 1:lowest priority,... 15:highest priority. */

void sh_intc_set_irl(void *opaque, int n, int level)

{

    struct intc_source *s = opaque;

    int i, irl = level ^ 15;

    for (i = 0; (s = sh_intc_source(s->parent, s->next_enum_id)); i++) {

	if (i == irl)

	    sh_intc_toggle_source(s, s->enable_count?0:1, s->asserted?0:1);

	else

	    if (s->asserted)

	        sh_intc_toggle_source(s, 0, -1);

    }

}