chip.c

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/*
 * IRQ chip definitions for INTC IRQs.
 *
 * Copyright (C) 2007, 2008 Magnus Damm
 * Copyright (C) 2009 - 2012 Paul Mundt
 *
 * This file is subject to the terms and conditions of the GNU General Public
 * License.  See the file "COPYING" in the main directory of this archive
 * for more details.
 */
#include <linux/cpumask.h>
#include <linux/bsearch.h>
#include <linux/io.h>
#include "internals.h"

void _intc_enable(struct irq_data *data, unsigned long handle)
{
    unsigned int irq = data->irq;
    struct intc_desc_int *d = get_intc_desc(irq);
    unsigned long addr;
    unsigned int cpu;

    for (cpu = 0; cpu < SMP_NR(d, _INTC_ADDR_E(handle)); cpu++) {
#ifdef CONFIG_SMP
        if (!cpumask_test_cpu(cpu, data->affinity))
            continue;
#endif
        addr = INTC_REG(d, _INTC_ADDR_E(handle), cpu);
        intc_enable_fns[_INTC_MODE(handle)](addr, handle, intc_reg_fns\
                            [_INTC_FN(handle)], irq);
    }

    intc_balancing_enable(irq);
}

static void intc_enable(struct irq_data *data)
{
    _intc_enable(data, (unsigned long)irq_data_get_irq_chip_data(data));
}

static void intc_disable(struct irq_data *data)
{
    unsigned int irq = data->irq;
    struct intc_desc_int *d = get_intc_desc(irq);
    unsigned long handle = (unsigned long)irq_data_get_irq_chip_data(data);
    unsigned long addr;
    unsigned int cpu;

    intc_balancing_disable(irq);

    for (cpu = 0; cpu < SMP_NR(d, _INTC_ADDR_D(handle)); cpu++) {
#ifdef CONFIG_SMP
        if (!cpumask_test_cpu(cpu, data->affinity))
            continue;
#endif
        addr = INTC_REG(d, _INTC_ADDR_D(handle), cpu);
        intc_disable_fns[_INTC_MODE(handle)](addr, handle,intc_reg_fns\
                             [_INTC_FN(handle)], irq);
    }
}

#ifdef CONFIG_SMP
/*
 * This is held with the irq desc lock held, so we don't require any
 * additional locking here at the intc desc level. The affinity mask is
 * later tested in the enable/disable paths.
 */
static int intc_set_affinity(struct irq_data *data,
                 const struct cpumask *cpumask,
                 bool force)
{
    if (!cpumask_intersects(cpumask, cpu_online_mask))
        return -1;

    cpumask_copy(data->affinity, cpumask);

    return IRQ_SET_MASK_OK_NOCOPY;
}
#endif

static void intc_mask_ack(struct irq_data *data)
{
    unsigned int irq = data->irq;
    struct intc_desc_int *d = get_intc_desc(irq);
    unsigned long handle = intc_get_ack_handle(irq);
    void __iomem *addr;

    intc_disable(data);

    /* read register and write zero only to the associated bit */
    if (handle) {
        unsigned int value;

        addr = (void __iomem *)INTC_REG(d, _INTC_ADDR_D(handle), 0);
        value = intc_set_field_from_handle(0, 1, handle);

        switch (_INTC_FN(handle)) {
        case REG_FN_MODIFY_BASE + 0:    /* 8bit */
            __raw_readb(addr);
            __raw_writeb(0xff ^ value, addr);
            break;
        case REG_FN_MODIFY_BASE + 1:    /* 16bit */
            __raw_readw(addr);
            __raw_writew(0xffff ^ value, addr);
            break;
        case REG_FN_MODIFY_BASE + 3:    /* 32bit */
            __raw_readl(addr);
            __raw_writel(0xffffffff ^ value, addr);
            break;
        default:
            BUG();
            break;
        }
    }
}

static struct intc_handle_int *intc_find_irq(struct intc_handle_int *hp,
                         unsigned int nr_hp,
                         unsigned int irq)
{
    struct intc_handle_int key;

    key.irq = irq;
    key.handle = 0;

    return bsearch(&key, hp, nr_hp, sizeof(*hp), intc_handle_int_cmp);
}

int intc_set_priority(unsigned int irq, unsigned int prio)
{
    struct intc_desc_int *d = get_intc_desc(irq);
    struct irq_data *data = irq_get_irq_data(irq);
    struct intc_handle_int *ihp;

    if (!intc_get_prio_level(irq) || prio <= 1)
        return -EINVAL;

    ihp = intc_find_irq(d->prio, d->nr_prio, irq);
    if (ihp) {
        if (prio >= (1 << _INTC_WIDTH(ihp->handle)))
            return -EINVAL;

        intc_set_prio_level(irq, prio);

        /*
         * only set secondary masking method directly
         * primary masking method is using intc_prio_level[irq]
         * priority level will be set during next enable()
         */
        if (_INTC_FN(ihp->handle) != REG_FN_ERR)
            _intc_enable(data, ihp->handle);
    }
    return 0;
}

#define SENSE_VALID_FLAG 0x80
#define VALID(x) (x | SENSE_VALID_FLAG)

static unsigned char intc_irq_sense_table[IRQ_TYPE_SENSE_MASK + 1] = {
    [IRQ_TYPE_EDGE_FALLING] = VALID(0),
    [IRQ_TYPE_EDGE_RISING] = VALID(1),
    [IRQ_TYPE_LEVEL_LOW] = VALID(2),
    /* SH7706, SH7707 and SH7709 do not support high level triggered */
#if !defined(CONFIG_CPU_SUBTYPE_SH7706) && \
    !defined(CONFIG_CPU_SUBTYPE_SH7707) && \
    !defined(CONFIG_CPU_SUBTYPE_SH7709)
    [IRQ_TYPE_LEVEL_HIGH] = VALID(3),
#endif
#if defined(CONFIG_ARM) /* all recent SH-Mobile / R-Mobile ARM support this */
    [IRQ_TYPE_EDGE_BOTH] = VALID(4),
#endif
};

static int intc_set_type(struct irq_data *data, unsigned int type)
{
    unsigned int irq = data->irq;
    struct intc_desc_int *d = get_intc_desc(irq);
    unsigned char value = intc_irq_sense_table[type & IRQ_TYPE_SENSE_MASK];
    struct intc_handle_int *ihp;
    unsigned long addr;

    if (!value)
        return -EINVAL;

    value &= ~SENSE_VALID_FLAG;

    ihp = intc_find_irq(d->sense, d->nr_sense, irq);
    if (ihp) {
        /* PINT has 2-bit sense registers, should fail on EDGE_BOTH */
        if (value >= (1 << _INTC_WIDTH(ihp->handle)))
            return -EINVAL;

        addr = INTC_REG(d, _INTC_ADDR_E(ihp->handle), 0);
        intc_reg_fns[_INTC_FN(ihp->handle)](addr, ihp->handle, value);
    }

    return 0;
}

struct irq_chip intc_irq_chip   = {
    .irq_mask       = intc_disable,
    .irq_unmask     = intc_enable,
    .irq_mask_ack       = intc_mask_ack,
    .irq_enable     = intc_enable,
    .irq_disable        = intc_disable,
    .irq_set_type       = intc_set_type,
#ifdef CONFIG_SMP
    .irq_set_affinity   = intc_set_affinity,
#endif
    .flags          = IRQCHIP_SKIP_SET_WAKE,
};