irq.c

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/*
 * linux/arch/sh/boards/se/7724/irq.c
 *
 * Copyright (C) 2009 Renesas Solutions Corp.
 *
 * Kuninori Morimoto <[email protected]>
 *
 * Based on  linux/arch/sh/boards/se/7722/irq.c
 * Copyright (C) 2007  Nobuhiro Iwamatsu
 *
 * Hitachi UL SolutionEngine 7724 Support.
 *
 * 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/init.h>
#include <linux/irq.h>
#include <linux/interrupt.h>
#include <linux/export.h>
#include <linux/topology.h>
#include <linux/io.h>
#include <linux/err.h>
#include <mach-se/mach/se7724.h>

struct fpga_irq {
    unsigned long  sraddr;
    unsigned long  mraddr;
    unsigned short mask;
    unsigned int   base;
};

static unsigned int fpga2irq(unsigned int irq)
{
    if (irq >= IRQ0_BASE &&
        irq <= IRQ0_END)
        return IRQ0_IRQ;
    else if (irq >= IRQ1_BASE &&
         irq <= IRQ1_END)
        return IRQ1_IRQ;
    else
        return IRQ2_IRQ;
}

static struct fpga_irq get_fpga_irq(unsigned int irq)
{
    struct fpga_irq set;

    switch (irq) {
    case IRQ0_IRQ:
        set.sraddr = IRQ0_SR;
        set.mraddr = IRQ0_MR;
        set.mask   = IRQ0_MASK;
        set.base   = IRQ0_BASE;
        break;
    case IRQ1_IRQ:
        set.sraddr = IRQ1_SR;
        set.mraddr = IRQ1_MR;
        set.mask   = IRQ1_MASK;
        set.base   = IRQ1_BASE;
        break;
    default:
        set.sraddr = IRQ2_SR;
        set.mraddr = IRQ2_MR;
        set.mask   = IRQ2_MASK;
        set.base   = IRQ2_BASE;
        break;
    }

    return set;
}

static void disable_se7724_irq(struct irq_data *data)
{
    unsigned int irq = data->irq;
    struct fpga_irq set = get_fpga_irq(fpga2irq(irq));
    unsigned int bit = irq - set.base;
    __raw_writew(__raw_readw(set.mraddr) | 0x0001 << bit, set.mraddr);
}

static void enable_se7724_irq(struct irq_data *data)
{
    unsigned int irq = data->irq;
    struct fpga_irq set = get_fpga_irq(fpga2irq(irq));
    unsigned int bit = irq - set.base;
    __raw_writew(__raw_readw(set.mraddr) & ~(0x0001 << bit), set.mraddr);
}

static struct irq_chip se7724_irq_chip __read_mostly = {
    .name       = "SE7724-FPGA",
    .irq_mask   = disable_se7724_irq,
    .irq_unmask = enable_se7724_irq,
};

static void se7724_irq_demux(unsigned int irq, struct irq_desc *desc)
{
    struct fpga_irq set = get_fpga_irq(irq);
    unsigned short intv = __raw_readw(set.sraddr);
    unsigned int ext_irq = set.base;

    intv &= set.mask;

    for (; intv; intv >>= 1, ext_irq++) {
        if (!(intv & 1))
            continue;

        generic_handle_irq(ext_irq);
    }
}

/*
 * Initialize IRQ setting
 */
void __init init_se7724_IRQ(void)
{
    int irq_base, i;

    __raw_writew(0xffff, IRQ0_MR);  /* mask all */
    __raw_writew(0xffff, IRQ1_MR);  /* mask all */
    __raw_writew(0xffff, IRQ2_MR);  /* mask all */
    __raw_writew(0x0000, IRQ0_SR);  /* clear irq */
    __raw_writew(0x0000, IRQ1_SR);  /* clear irq */
    __raw_writew(0x0000, IRQ2_SR);  /* clear irq */
    __raw_writew(0x002a, IRQ_MODE); /* set irq type */

    irq_base = irq_alloc_descs(SE7724_FPGA_IRQ_BASE, SE7724_FPGA_IRQ_BASE,
                   SE7724_FPGA_IRQ_NR, numa_node_id());
    if (IS_ERR_VALUE(irq_base)) {
        pr_err("%s: failed hooking irqs for FPGA\n", __func__);
        return;
    }

    for (i = 0; i < SE7724_FPGA_IRQ_NR; i++)
        irq_set_chip_and_handler_name(irq_base + i, &se7724_irq_chip,
                          handle_level_irq, "level");

    irq_set_chained_handler(IRQ0_IRQ, se7724_irq_demux);
    irq_set_irq_type(IRQ0_IRQ, IRQ_TYPE_LEVEL_LOW);

    irq_set_chained_handler(IRQ1_IRQ, se7724_irq_demux);
    irq_set_irq_type(IRQ1_IRQ, IRQ_TYPE_LEVEL_LOW);

    irq_set_chained_handler(IRQ2_IRQ, se7724_irq_demux);
    irq_set_irq_type(IRQ2_IRQ, IRQ_TYPE_LEVEL_LOW);
}