release/src-rt-6.x.4708/linux/linux-2.6.36/arch/mips/pmc-sierra/msp71xx/msp_irq_slp.c

   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 #include <asm/system.h>
  20
  21 #include <msp_slp_int.h>
  22 #include <msp_regs.h>
  23
  24 static inline void unmask_msp_slp_irq(unsigned int irq)
  25 {
  26         /* check for PER interrupt range */
  27         if (irq < MSP_PER_INTBASE)
  28                 *SLP_INT_MSK_REG |= (1 << (irq - MSP_SLP_INTBASE));
  29         else
  30                 *PER_INT_MSK_REG |= (1 << (irq - MSP_PER_INTBASE));
  31 }
  32
  33 static inline void mask_msp_slp_irq(unsigned int irq)
  34 {
  35         /* check for PER interrupt range */
  36         if (irq < MSP_PER_INTBASE)
  37                 *SLP_INT_MSK_REG &= ~(1 << (irq - MSP_SLP_INTBASE));
  38         else
  39                 *PER_INT_MSK_REG &= ~(1 << (irq - MSP_PER_INTBASE));
  40 }
  41
  42 /*
  43  * While we ack the interrupt interrupts are disabled and thus we don't need
  44  * to deal with concurrency issues.  Same for msp_slp_irq_end.
  45  */
  46 static inline void ack_msp_slp_irq(unsigned int irq)
  47 {
  48         /* check for PER interrupt range */
  49         if (irq < MSP_PER_INTBASE)
  50                 *SLP_INT_STS_REG = (1 << (irq - MSP_SLP_INTBASE));
  51         else
  52                 *PER_INT_STS_REG = (1 << (irq - MSP_PER_INTBASE));
  53 }
  54
  55 static struct irq_chip msp_slp_irq_controller = {
  56         .name = "MSP_SLP",
  57         .ack = ack_msp_slp_irq,
  58         .mask = mask_msp_slp_irq,
  59         .unmask = unmask_msp_slp_irq,
  60 };
  61
  62 void __init msp_slp_irq_init(void)
  63 {
  64         int i;
  65
  66         /* Mask/clear interrupts. */
  67         *SLP_INT_MSK_REG = 0x00000000;
  68         *PER_INT_MSK_REG = 0x00000000;
  69         *SLP_INT_STS_REG = 0xFFFFFFFF;
  70         *PER_INT_STS_REG = 0xFFFFFFFF;
  71
  72         /* initialize all the IRQ descriptors */
  73         for (i = MSP_SLP_INTBASE; i < MSP_PER_INTBASE + 32; i++)
  74                 set_irq_chip_and_handler(i, &msp_slp_irq_controller,
  75                                          handle_level_irq);
  76 }
  77
  78 void msp_slp_irq_dispatch(void)
  79 {
  80         u32 pending;
  81         int intbase;
  82
  83         intbase = MSP_SLP_INTBASE;
  84         pending = *SLP_INT_STS_REG & *SLP_INT_MSK_REG;
  85
  86         /* check for PER interrupt */
  87         if (pending == (1 << (MSP_INT_PER - MSP_SLP_INTBASE))) {
  88                 intbase = MSP_PER_INTBASE;
  89                 pending = *PER_INT_STS_REG & *PER_INT_MSK_REG;
  90         }
  91
  92         /* check for spurious interrupt */
  93         if (pending == 0x00000000) {
  94                 printk(KERN_ERR "Spurious %s interrupt?\n",
  95                         (intbase == MSP_SLP_INTBASE) ? "SLP" : "PER");
  96                 return;
  97         }
  98
  99         /* dispatch the irq */
 100         do_IRQ(ffs(pending) + intbase - 1);
 101 }