1/*
  2 * This file define the irq handler for MSP SLM subsystem interrupts.
  3 *
  4 * Copyright 2005-2006 PMC-Sierra, Inc, derived from irq_cpu.c
  5 * Author: Andrew Hughes, Andrew_Hughes@pmc-sierra.com
  6 *
  7 * This program is free software; you can redistribute	it and/or modify it
  8 * under  the terms of	the GNU General	 Public License as published by the
  9 * Free Software Foundation;  either version 2 of the  License, or (at your
 10 * option) any later version.
 11 */
 12
 13#include <linux/init.h>
 14#include <linux/interrupt.h>
 15#include <linux/kernel.h>
 16#include <linux/bitops.h>
 17
 18#include <asm/mipsregs.h>
 19
 20#include <msp_slp_int.h>
 21#include <msp_regs.h>
 22
 23static inline void unmask_msp_slp_irq(struct irq_data *d)
 24{
 25	unsigned int irq = d->irq;
 26
 27	/* check for PER interrupt range */
 28	if (irq < MSP_PER_INTBASE)
 29		*SLP_INT_MSK_REG |= (1 << (irq - MSP_SLP_INTBASE));
 30	else
 31		*PER_INT_MSK_REG |= (1 << (irq - MSP_PER_INTBASE));
 32}
 33
 34static inline void mask_msp_slp_irq(struct irq_data *d)
 35{
 36	unsigned int irq = d->irq;
 37
 38	/* check for PER interrupt range */
 39	if (irq < MSP_PER_INTBASE)
 40		*SLP_INT_MSK_REG &= ~(1 << (irq - MSP_SLP_INTBASE));
 41	else
 42		*PER_INT_MSK_REG &= ~(1 << (irq - MSP_PER_INTBASE));
 43}
 44
 45/*
 46 * While we ack the interrupt interrupts are disabled and thus we don't need
 47 * to deal with concurrency issues.  Same for msp_slp_irq_end.
 48 */
 49static inline void ack_msp_slp_irq(struct irq_data *d)
 50{
 51	unsigned int irq = d->irq;
 52
 53	/* check for PER interrupt range */
 54	if (irq < MSP_PER_INTBASE)
 55		*SLP_INT_STS_REG = (1 << (irq - MSP_SLP_INTBASE));
 56	else
 57		*PER_INT_STS_REG = (1 << (irq - MSP_PER_INTBASE));
 58}
 59
 60static struct irq_chip msp_slp_irq_controller = {
 61	.name = "MSP_SLP",
 62	.irq_ack = ack_msp_slp_irq,
 63	.irq_mask = mask_msp_slp_irq,
 64	.irq_unmask = unmask_msp_slp_irq,
 65};
 66
 67void __init msp_slp_irq_init(void)
 68{
 69	int i;
 70
 71	/* Mask/clear interrupts. */
 72	*SLP_INT_MSK_REG = 0x00000000;
 73	*PER_INT_MSK_REG = 0x00000000;
 74	*SLP_INT_STS_REG = 0xFFFFFFFF;
 75	*PER_INT_STS_REG = 0xFFFFFFFF;
 76
 77	/* initialize all the IRQ descriptors */
 78	for (i = MSP_SLP_INTBASE; i < MSP_PER_INTBASE + 32; i++)
 79		irq_set_chip_and_handler(i, &msp_slp_irq_controller,
 80					 handle_level_irq);
 81}
 82
 83void msp_slp_irq_dispatch(void)
 84{
 85	u32 pending;
 86	int intbase;
 87
 88	intbase = MSP_SLP_INTBASE;
 89	pending = *SLP_INT_STS_REG & *SLP_INT_MSK_REG;
 90
 91	/* check for PER interrupt */
 92	if (pending == (1 << (MSP_INT_PER - MSP_SLP_INTBASE))) {
 93		intbase = MSP_PER_INTBASE;
 94		pending = *PER_INT_STS_REG & *PER_INT_MSK_REG;
 95	}
 96
 97	/* check for spurious interrupt */
 98	if (pending == 0x00000000) {
 99		printk(KERN_ERR "Spurious %s interrupt?\n",
100			(intbase == MSP_SLP_INTBASE) ? "SLP" : "PER");
101		return;
102	}
103
104	/* dispatch the irq */
105	do_IRQ(ffs(pending) + intbase - 1);
106}