target/linux/amazon/files/arch/mips/amazon/interrupt.c

   1 /*
   2  *  Gary Jennejohn (C) 2003 <gj@denx.de>
   3  *  Copyright (C) 2007 Felix Fietkau <nbd@openwrt.org>
   4  *  Copyright (C) 2007 John Crispin <blogic@openwrt.org>
   5  *
   6  *  This program is free software; you can distribute it and/or modify it
   7  *  under the terms of the GNU General Public License (Version 2) as
   8  *  published by the Free Software Foundation.
   9  *
  10  *  This program is distributed in the hope it will be useful, but WITHOUT
  11  *  ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  12  *  FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  13  *  for more details.
  14  *
  15  *  You should have received a copy of the GNU General Public License along
  16  *  with this program; if not, write to the Free Software Foundation, Inc.,
  17  *  59 Temple Place - Suite 330, Boston MA 02111-1307, USA.
  18  *
  19  * Routines for generic manipulation of the interrupts found on the
  20  * AMAZON boards.
  21  */
  22
  23 #include <linux/init.h>
  24 #include <linux/sched.h>
  25 #include <linux/slab.h>
  26 #include <linux/interrupt.h>
  27 #include <linux/kernel_stat.h>
  28 #include <linux/module.h>
  29
  30 #include <asm/amazon/amazon.h>
  31 #include <asm/amazon/irq.h>
  32 #include <asm/bootinfo.h>
  33 #include <asm/irq_cpu.h>
  34 #include <asm/irq.h>
  35 #include <asm/time.h>
  36
  37 static void amazon_disable_irq(unsigned int irq_nr)
  38 {
  39         int i;
  40         u32 amazon_ier = AMAZON_ICU_IM0_IER;
  41
  42         if (irq_nr <= INT_NUM_IM0_IRL11 && irq_nr >= INT_NUM_IM0_IRL0)
  43                 amazon_writel(amazon_readl(amazon_ier) & (~(AMAZON_DMA_H_MASK)), amazon_ier);
  44         else {
  45                 irq_nr -= INT_NUM_IRQ0;
  46                 for (i = 0; i <= 4; i++)
  47                 {
  48                         if (irq_nr <= 31)
  49                         amazon_writel(amazon_readl(amazon_ier) & ~(1 << irq_nr ), amazon_ier);
  50                         amazon_ier += 0x10;
  51                         irq_nr -= 32;
  52                 }
  53         }
  54 }
  55
  56 static void amazon_mask_and_ack_irq(unsigned int irq_nr)
  57 {
  58         int i;
  59         u32 amazon_ier = AMAZON_ICU_IM0_IER;
  60         u32 amazon_isr = AMAZON_ICU_IM0_ISR;
  61
  62         if (irq_nr <= INT_NUM_IM0_IRL11 && irq_nr >= INT_NUM_IM0_IRL0){
  63                 amazon_writel(amazon_readl(amazon_ier) & (~(AMAZON_DMA_H_MASK)), amazon_ier);
  64                 amazon_writel(AMAZON_DMA_H_MASK, amazon_isr);
  65         } else {
  66                 irq_nr -= INT_NUM_IRQ0;
  67                 for (i = 0; i <= 4; i++)
  68                 {
  69                         if (irq_nr <= 31){
  70                         amazon_writel(amazon_readl(amazon_ier) & ~(1 << irq_nr ), amazon_ier);
  71                                 amazon_writel((1 << irq_nr ), amazon_isr);
  72                         }
  73                         amazon_ier += 0x10;
  74                         amazon_isr += 0x10;
  75                         irq_nr -= 32;
  76                 }
  77         }
  78 }
  79
  80 static void amazon_enable_irq(unsigned int irq_nr)
  81 {
  82         int i;
  83         u32 amazon_ier = AMAZON_ICU_IM0_IER;
  84
  85         if (irq_nr <= INT_NUM_IM0_IRL11 && irq_nr >= INT_NUM_IM0_IRL0)
  86                 amazon_writel(amazon_readl(amazon_ier) | AMAZON_DMA_H_MASK, amazon_ier);
  87         else {
  88                 irq_nr -= INT_NUM_IRQ0;
  89                 for (i = 0; i <= 4; i++)
  90                 {
  91                         if (irq_nr <= 31)
  92                                 amazon_writel(amazon_readl(amazon_ier) | (1 << irq_nr ), amazon_ier);
  93                         amazon_ier += 0x10;
  94                         irq_nr -= 32;
  95                 }
  96         }
  97 }
  98
  99 static unsigned int amazon_startup_irq(unsigned int irq)
 100 {
 101         amazon_enable_irq(irq);
 102         return 0;
 103 }
 104
 105 static void amazon_end_irq(unsigned int irq)
 106 {
 107         if (!(irq_desc[irq].status & (IRQ_DISABLED|IRQ_INPROGRESS))) {
 108                 amazon_enable_irq(irq);
 109         }
 110 }
 111
 112 static struct hw_interrupt_type amazon_irq_type = {
 113         "AMAZON",
 114         .startup = amazon_startup_irq,
 115         .enable = amazon_enable_irq,
 116         .disable = amazon_disable_irq,
 117         .unmask = amazon_enable_irq,
 118         .ack = amazon_mask_and_ack_irq,
 119         .mask = amazon_disable_irq,
 120         .mask_ack = amazon_mask_and_ack_irq,
 121         .end = amazon_end_irq
 122 };
 123
 124 /* Cascaded interrupts from IM0-4 */
 125 static inline void amazon_hw_irqdispatch(u8 line)
 126 {
 127         u32 irq;
 128
 129         irq = (amazon_readl(AMAZON_ICU_IM_VEC) >> (line * 5)) & AMAZON_ICU_IM0_VEC_MASK;
 130         if (line == 0 && irq <= 11 && irq >= 0) {
 131                 //DMA fixed to IM0_IRL0
 132                 irq = 0;
 133         }
 134         do_IRQ(irq + INT_NUM_IRQ0 + (line * 32));
 135 }
 136
 137 asmlinkage void plat_irq_dispatch(void)
 138 {
 139         unsigned int pending = read_c0_status() & read_c0_cause() & ST0_IM;
 140         if (pending & CAUSEF_IP7){
 141                 do_IRQ(MIPS_CPU_TIMER_IRQ);
 142                 goto out;
 143         } else {
 144                 unsigned int i;
 145                 for (i = 0; i <= 4; i++)
 146                 {
 147                         if(pending & (CAUSEF_IP2 << i)){
 148                                 amazon_hw_irqdispatch(i);
 149                                 goto out;
 150                         }
 151                 }
 152         }
 153         printk("Spurious IRQ: CAUSE=0x%08x\n", read_c0_status());
 154 out:
 155         return;
 156 }
 157
 158 static struct irqaction cascade = {
 159         .handler        = no_action,
 160         .flags          = SA_INTERRUPT,
 161         .name           = "cascade",
 162 };
 163
 164 void __init arch_init_irq(void)
 165 {
 166         int i;
 167
 168         /* mask all interrupt sources */
 169         for(i = 0; i <= 4; i++){
 170                 amazon_writel(0, AMAZON_ICU_IM0_IER + (i * 0x10));
 171         }
 172
 173         mips_cpu_irq_init();
 174
 175         /* set up irq cascade */
 176         for (i = 2; i <= 6; i++) {
 177                 setup_irq(i, &cascade);
 178         }
 179
 180         for (i = INT_NUM_IRQ0; i <= INT_NUM_IM4_IRL31; i++) {
 181                 irq_desc[i].status      = IRQ_DISABLED;
 182                 irq_desc[i].action      = 0;
 183                 irq_desc[i].depth       = 1;
 184                 set_irq_chip(i, &amazon_irq_type);
 185         }
 186 }