target/linux/ifxmips/files/arch/mips/ifxmips/irq.c

   1 /*
   2  *   This program is free software; you can redistribute it and/or modify
   3  *   it under the terms of the GNU General Public License as published by
   4  *   the Free Software Foundation; either version 2 of the License, or
   5  *   (at your option) any later version.
   6  *
   7  *   This program is distributed in the hope that it will be useful,
   8  *   but WITHOUT ANY WARRANTY; without even the implied warranty of
   9  *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  10  *   GNU General Public License for more details.
  11  *
  12  *   You should have received a copy of the GNU General Public License
  13  *   along with this program; if not, write to the Free Software
  14  *   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307, USA.
  15  *
  16  *   Copyright (C) 2005 Wu Qi Ming infineon
  17  *   Copyright (C) 2007 John Crispin <blogic@openwrt.org>
  18  */
  19
  20 #include <linux/init.h>
  21 #include <linux/sched.h>
  22 #include <linux/slab.h>
  23 #include <linux/interrupt.h>
  24 #include <linux/kernel_stat.h>
  25 #include <linux/module.h>
  26
  27 #include <asm/bootinfo.h>
  28 #include <asm/irq.h>
  29 #include <asm/irq_cpu.h>
  30
  31 #include <ifxmips.h>
  32 #include <ifxmips_irq.h>
  33
  34 void ifxmips_disable_irq(unsigned int irq_nr)
  35 {
  36         int i;
  37         u32 *ifxmips_ier = IFXMIPS_ICU_IM0_IER;
  38
  39         irq_nr -= INT_NUM_IRQ0;
  40         for (i = 0; i <= 4; i++) {
  41                 if (irq_nr < INT_NUM_IM_OFFSET) {
  42                         ifxmips_w32(ifxmips_r32(ifxmips_ier) & ~(1 << irq_nr),
  43                                 ifxmips_ier);
  44                         return;
  45                 }
  46                 ifxmips_ier += IFXMIPS_ICU_OFFSET;
  47                 irq_nr -= INT_NUM_IM_OFFSET;
  48         }
  49 }
  50 EXPORT_SYMBOL(ifxmips_disable_irq);
  51
  52 void ifxmips_mask_and_ack_irq(unsigned int irq_nr)
  53 {
  54         int i;
  55         u32 *ifxmips_ier = IFXMIPS_ICU_IM0_IER;
  56         u32 *ifxmips_isr = IFXMIPS_ICU_IM0_ISR;
  57
  58         irq_nr -= INT_NUM_IRQ0;
  59         for (i = 0; i <= 4; i++) {
  60                 if (irq_nr < INT_NUM_IM_OFFSET) {
  61                         ifxmips_w32(ifxmips_r32(ifxmips_ier) & ~(1 << irq_nr),
  62                                 ifxmips_ier);
  63                         ifxmips_w32((1 << irq_nr), ifxmips_isr);
  64                         return;
  65                 }
  66                 ifxmips_ier += IFXMIPS_ICU_OFFSET;
  67                 ifxmips_isr += IFXMIPS_ICU_OFFSET;
  68                 irq_nr -= INT_NUM_IM_OFFSET;
  69         }
  70 }
  71 EXPORT_SYMBOL(ifxmips_mask_and_ack_irq);
  72
  73 void ifxmips_enable_irq(unsigned int irq_nr)
  74 {
  75         int i;
  76         u32 *ifxmips_ier = IFXMIPS_ICU_IM0_IER;
  77
  78         irq_nr -= INT_NUM_IRQ0;
  79         for (i = 0; i <= 4; i++) {
  80                 if (irq_nr < INT_NUM_IM_OFFSET) {
  81                         ifxmips_w32(ifxmips_r32(ifxmips_ier) | (1 << irq_nr),
  82                                 ifxmips_ier);
  83                         return;
  84                 }
  85                 ifxmips_ier += IFXMIPS_ICU_OFFSET;
  86                 irq_nr -= INT_NUM_IM_OFFSET;
  87         }
  88 }
  89 EXPORT_SYMBOL(ifxmips_enable_irq);
  90
  91 static unsigned int ifxmips_startup_irq(unsigned int irq)
  92 {
  93         ifxmips_enable_irq(irq);
  94         return 0;
  95 }
  96
  97 static void ifxmips_end_irq(unsigned int irq)
  98 {
  99         if (!(irq_desc[irq].status & (IRQ_DISABLED | IRQ_INPROGRESS)))
 100                 ifxmips_enable_irq(irq);
 101 }
 102
 103 static struct hw_interrupt_type ifxmips_irq_type = {
 104         "IFXMIPS",
 105         .startup = ifxmips_startup_irq,
 106         .enable = ifxmips_enable_irq,
 107         .disable = ifxmips_disable_irq,
 108         .unmask = ifxmips_enable_irq,
 109         .ack = ifxmips_end_irq,
 110         .mask = ifxmips_disable_irq,
 111         .mask_ack = ifxmips_mask_and_ack_irq,
 112         .end = ifxmips_end_irq,
 113 };
 114
 115 /* silicon bug causes only the msb set to 1 to be valid. all
 116    other bits might be bogus */
 117 static inline int ls1bit32(unsigned long x)
 118 {
 119         __asm__ (
 120                 ".set push \n"
 121                 ".set mips32 \n"
 122                 "clz %0, %1 \n"
 123                 ".set pop \n"
 124                 : "=r" (x)
 125                 : "r" (x));
 126         return 31 - x;
 127 }
 128
 129 void ifxmips_hw_irqdispatch(int module)
 130 {
 131         u32 irq;
 132
 133         irq = ifxmips_r32(IFXMIPS_ICU_IM0_IOSR + (module * IFXMIPS_ICU_OFFSET));
 134         if (irq == 0)
 135                 return;
 136
 137         /* we need to do this due to a silicon bug */
 138         irq = ls1bit32(irq);
 139         do_IRQ((int)irq + INT_NUM_IM0_IRL0 + (INT_NUM_IM_OFFSET * module));
 140
 141         if ((irq == 22) && (module == 0))
 142                 ifxmips_w32(ifxmips_r32(IFXMIPS_EBU_PCC_ISTAT) | 0x10,
 143                         IFXMIPS_EBU_PCC_ISTAT);
 144 }
 145
 146 #ifdef CONFIG_CPU_MIPSR2_IRQ_VI
 147 #define DEFINE_HWx_IRQDISPATCH(x) \
 148 static void ifxmips_hw ## x ## _irqdispatch(void)\
 149 {\
 150         ifxmips_hw_irqdispatch(x); \
 151 }
 152 static void ifxmips_hw5_irqdispatch(void)
 153 {
 154         do_IRQ(MIPS_CPU_TIMER_IRQ);
 155 }
 156 DEFINE_HWx_IRQDISPATCH(0)
 157 DEFINE_HWx_IRQDISPATCH(1)
 158 DEFINE_HWx_IRQDISPATCH(2)
 159 DEFINE_HWx_IRQDISPATCH(3)
 160 DEFINE_HWx_IRQDISPATCH(4)
 161 /*DEFINE_HWx_IRQDISPATCH(5)*/
 162 #endif /* #ifdef CONFIG_CPU_MIPSR2_IRQ_VI */
 163
 164 asmlinkage void plat_irq_dispatch(void)
 165 {
 166         unsigned int pending = read_c0_status() & read_c0_cause() & ST0_IM;
 167         unsigned int i;
 168
 169         if (pending & CAUSEF_IP7) {
 170                 do_IRQ(MIPS_CPU_TIMER_IRQ);
 171                 goto out;
 172         } else {
 173                 for (i = 0; i < 5; i++) {
 174                         if (pending & (CAUSEF_IP2 << i)) {
 175                                 ifxmips_hw_irqdispatch(i);
 176                                 goto out;
 177                         }
 178                 }
 179         }
 180         printk(KERN_ALERT "Spurious IRQ: CAUSE=0x%08x\n", read_c0_status());
 181
 182 out:
 183         return;
 184 }
 185
 186 static struct irqaction cascade = {
 187         .handler = no_action,
 188         .flags = IRQF_DISABLED,
 189         .name = "cascade",
 190 };
 191
 192 void __init arch_init_irq(void)
 193 {
 194         int i;
 195
 196         for (i = 0; i < 5; i++)
 197                 ifxmips_w32(0, IFXMIPS_ICU_IM0_IER + (i * IFXMIPS_ICU_OFFSET));
 198
 199         mips_cpu_irq_init();
 200
 201         for (i = 2; i <= 6; i++)
 202                 setup_irq(i, &cascade);
 203
 204 #ifdef CONFIG_CPU_MIPSR2_IRQ_VI
 205         if (cpu_has_vint) {
 206                 printk(KERN_INFO "Setting up vectored interrupts\n");
 207                 set_vi_handler(2, ifxmips_hw0_irqdispatch);
 208                 set_vi_handler(3, ifxmips_hw1_irqdispatch);
 209                 set_vi_handler(4, ifxmips_hw2_irqdispatch);
 210                 set_vi_handler(5, ifxmips_hw3_irqdispatch);
 211                 set_vi_handler(6, ifxmips_hw4_irqdispatch);
 212                 set_vi_handler(7, ifxmips_hw5_irqdispatch);
 213         }
 214 #endif /* CONFIG_CPU_MIPSR2_IRQ_VI */
 215
 216         for (i = INT_NUM_IRQ0; i <= (INT_NUM_IRQ0 + (5 * INT_NUM_IM_OFFSET));
 217                 i++)
 218                 set_irq_chip_and_handler(i, &ifxmips_irq_type,
 219                         handle_level_irq);
 220
 221         #if !defined(CONFIG_MIPS_MT_SMP) && !defined(CONFIG_MIPS_MT_SMTC)
 222         set_c0_status(IE_IRQ0 | IE_IRQ1 | IE_IRQ2 |
 223                 IE_IRQ3 | IE_IRQ4 | IE_IRQ5);
 224         #else
 225         set_c0_status(IE_SW0 | IE_SW1 | IE_IRQ0 | IE_IRQ1 |
 226                 IE_IRQ2 | IE_IRQ3 | IE_IRQ4 | IE_IRQ5);
 227         #endif
 228 }
 229
 230 void __cpuinit arch_fixup_c0_irqs(void)
 231 {
 232         /* FIXME: check for CPUID and only do fix for specific chips/versions */
 233         cp0_compare_irq = CP0_LEGACY_COMPARE_IRQ;
 234         cp0_perfcount_irq = CP0_LEGACY_PERFCNT_IRQ;
 235 }