arch/mips/txx9/rbtx4939/irq.c

   1 /*
   2  * Toshiba RBTX4939 interrupt routines
   3  * Based on linux/arch/mips/txx9/rbtx4938/irq.c,
   4  *          and RBTX49xx patch from CELF patch archive.
   5  *
   6  * Copyright (C) 2000-2001,2005-2006 Toshiba Corporation
   7  * 2003-2005 (c) MontaVista Software, Inc. This file is licensed under the
   8  * terms of the GNU General Public License version 2. This program is
   9  * licensed "as is" without any warranty of any kind, whether express
  10  * or implied.
  11  */
  12 #include <linux/init.h>
  13 #include <linux/interrupt.h>
  14 #include <linux/irq.h>
  15 #include <asm/mipsregs.h>
  16 #include <asm/txx9/rbtx4939.h>
  17
  18 /*
  19  * RBTX4939 IOC controller definition
  20  */
  21
  22 static void rbtx4939_ioc_irq_unmask(struct irq_data *d)
  23 {
  24         int ioc_nr = d->irq - RBTX4939_IRQ_IOC;
  25
  26         writeb(readb(rbtx4939_ien_addr) | (1 << ioc_nr), rbtx4939_ien_addr);
  27 }
  28
  29 static void rbtx4939_ioc_irq_mask(struct irq_data *d)
  30 {
  31         int ioc_nr = d->irq - RBTX4939_IRQ_IOC;
  32
  33         writeb(readb(rbtx4939_ien_addr) & ~(1 << ioc_nr), rbtx4939_ien_addr);
  34         mmiowb();
  35 }
  36
  37 static struct irq_chip rbtx4939_ioc_irq_chip = {
  38         .name           = "IOC",
  39         .irq_mask       = rbtx4939_ioc_irq_mask,
  40         .irq_unmask     = rbtx4939_ioc_irq_unmask,
  41 };
  42
  43
  44 static inline int rbtx4939_ioc_irqroute(void)
  45 {
  46         unsigned char istat = readb(rbtx4939_ifac2_addr);
  47
  48         if (unlikely(istat == 0))
  49                 return -1;
  50         return RBTX4939_IRQ_IOC + __fls8(istat);
  51 }
  52
  53 static int rbtx4939_irq_dispatch(int pending)
  54 {
  55         int irq;
  56
  57         if (pending & CAUSEF_IP7)
  58                 return MIPS_CPU_IRQ_BASE + 7;
  59         irq = tx4939_irq();
  60         if (likely(irq >= 0)) {
  61                 /* redirect IOC interrupts */
  62                 switch (irq) {
  63                 case RBTX4939_IRQ_IOCINT:
  64                         irq = rbtx4939_ioc_irqroute();
  65                         break;
  66                 }
  67         } else if (pending & CAUSEF_IP0)
  68                 irq = MIPS_CPU_IRQ_BASE + 0;
  69         else if (pending & CAUSEF_IP1)
  70                 irq = MIPS_CPU_IRQ_BASE + 1;
  71         else
  72                 irq = -1;
  73         return irq;
  74 }
  75
  76 void __init rbtx4939_irq_setup(void)
  77 {
  78         int i;
  79
  80         /* mask all IOC interrupts */
  81         writeb(0, rbtx4939_ien_addr);
  82
  83         /* clear SoftInt interrupts */
  84         writeb(0, rbtx4939_softint_addr);
  85
  86         txx9_irq_dispatch = rbtx4939_irq_dispatch;
  87
  88         tx4939_irq_init();
  89         for (i = RBTX4939_IRQ_IOC;
  90              i < RBTX4939_IRQ_IOC + RBTX4939_NR_IRQ_IOC; i++)
  91                 irq_set_chip_and_handler(i, &rbtx4939_ioc_irq_chip,
  92                                          handle_level_irq);
  93
  94         irq_set_chained_handler(RBTX4939_IRQ_IOCINT, handle_simple_irq);
  95 }