Subversion Repositories or1k_soc_on_altera_embedded_dev_kit

/* irq-mb93093.c: MB93093 FPGA interrupt handling

 *

 * Copyright (C) 2006 Red Hat, Inc. All Rights Reserved.

 * Written by David Howells (dhowells@redhat.com)

 *

 * 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/ptrace.h>

#include <linux/errno.h>

#include <linux/signal.h>

#include <linux/sched.h>

#include <linux/ioport.h>

#include <linux/interrupt.h>

#include <linux/init.h>

#include <linux/irq.h>

#include <linux/bitops.h>

#include <asm/io.h>

#include <asm/system.h>

#include <asm/delay.h>

#include <asm/irq.h>

#include <asm/irc-regs.h>

#define __reg16(ADDR) (*(volatile unsigned short *)(__region_CS2 + (ADDR)))

#define __get_IMR()     ({ __reg16(0x0a); })

#define __set_IMR(M)    do { __reg16(0x0a) = (M);  wmb(); } while(0)

#define __get_IFR()     ({ __reg16(0x02); })

#define __clr_IFR(M)    do { __reg16(0x02) = ~(M); wmb(); } while(0)

/*

 * off-CPU FPGA PIC operations

 */

static void frv_fpga_mask(unsigned int irq)

{

        uint16_t imr = __get_IMR();

        imr |= 1 << (irq - IRQ_BASE_FPGA);

        __set_IMR(imr);

}

static void frv_fpga_ack(unsigned int irq)

{

        __clr_IFR(1 << (irq - IRQ_BASE_FPGA));

}

static void frv_fpga_mask_ack(unsigned int irq)

{

        uint16_t imr = __get_IMR();

        imr |= 1 << (irq - IRQ_BASE_FPGA);

        __set_IMR(imr);

        __clr_IFR(1 << (irq - IRQ_BASE_FPGA));

}

static void frv_fpga_unmask(unsigned int irq)

{

        uint16_t imr = __get_IMR();

        imr &= ~(1 << (irq - IRQ_BASE_FPGA));

        __set_IMR(imr);

}

static struct irq_chip frv_fpga_pic = {

        .name           = "mb93093",

        .ack            = frv_fpga_ack,

        .mask           = frv_fpga_mask,

        .mask_ack       = frv_fpga_mask_ack,

        .unmask         = frv_fpga_unmask,

        .end            = frv_fpga_end,

};

/*

 * FPGA PIC interrupt handler

 */

static irqreturn_t fpga_interrupt(int irq, void *_mask)

{

        uint16_t imr, mask = (unsigned long) _mask;

        imr = __get_IMR();

        mask = mask & ~imr & __get_IFR();

        /* poll all the triggered IRQs */

        while (mask) {

                int irq;

                asm("scan %1,gr0,%0" : "=r"(irq) : "r"(mask));

                irq = 31 - irq;

                mask &= ~(1 << irq);

                generic_irq_handle(IRQ_BASE_FPGA + irq);

        }

        return IRQ_HANDLED;

}

/*

 * define an interrupt action for each FPGA PIC output

 * - use dev_id to indicate the FPGA PIC input to output mappings

 */

static struct irqaction fpga_irq[1]  = {

        [0] = {

                .handler        = fpga_interrupt,

                .flags          = IRQF_DISABLED,

                .mask           = CPU_MASK_NONE,

                .name           = "fpga.0",

                .dev_id         = (void *) 0x0700UL,

        }

};

/*

 * initialise the motherboard FPGA's PIC

 */

void __init fpga_init(void)

{

        int irq;

        /* all PIC inputs are all set to be edge triggered */

        __set_IMR(0x0700);

        __clr_IFR(0x0000);

        for (irq = IRQ_BASE_FPGA + 8; irq <= IRQ_BASE_FPGA + 10; irq++)

                set_irq_chip_and_handler(irq, &frv_fpga_pic, handle_edge_irq);

        /* the FPGA drives external IRQ input #2 on the CPU PIC */

        setup_irq(IRQ_CPU_EXTERNAL2, &fpga_irq[0]);

}