arch/mips/jazz/irq.c

   1 /*
   2  * This file is subject to the terms and conditions of the GNU General Public
   3  * License.  See the file "COPYING" in the main directory of this archive
   4  * for more details.
   5  *
   6  * Copyright (C) 1992 Linus Torvalds
   7  * Copyright (C) 1994 - 2001, 2003 Ralf Baechle
   8  */
   9 #include <linux/init.h>
  10 #include <linux/interrupt.h>
  11 #include <linux/kernel.h>
  12 #include <linux/spinlock.h>
  13
  14 #include <asm/i8259.h>
  15 #include <asm/io.h>
  16 #include <asm/jazz.h>
  17
  18 static DEFINE_SPINLOCK(r4030_lock);
  19
  20 static void enable_r4030_irq(unsigned int irq)
  21 {
  22         unsigned int mask = 1 << (irq - JAZZ_PARALLEL_IRQ);
  23         unsigned long flags;
  24
  25         spin_lock_irqsave(&r4030_lock, flags);
  26         mask |= r4030_read_reg16(JAZZ_IO_IRQ_ENABLE);
  27         r4030_write_reg16(JAZZ_IO_IRQ_ENABLE, mask);
  28         spin_unlock_irqrestore(&r4030_lock, flags);
  29 }
  30
  31 static unsigned int startup_r4030_irq(unsigned int irq)
  32 {
  33         enable_r4030_irq(irq);
  34         return 0; /* never anything pending */
  35 }
  36
  37 #define shutdown_r4030_irq      disable_r4030_irq
  38
  39 void disable_r4030_irq(unsigned int irq)
  40 {
  41         unsigned int mask = ~(1 << (irq - JAZZ_PARALLEL_IRQ));
  42         unsigned long flags;
  43
  44         spin_lock_irqsave(&r4030_lock, flags);
  45         mask &= r4030_read_reg16(JAZZ_IO_IRQ_ENABLE);
  46         r4030_write_reg16(JAZZ_IO_IRQ_ENABLE, mask);
  47         spin_unlock_irqrestore(&r4030_lock, flags);
  48 }
  49
  50 #define mask_and_ack_r4030_irq disable_r4030_irq
  51
  52 static void end_r4030_irq(unsigned int irq)
  53 {
  54         if (!(irq_desc[irq].status & (IRQ_DISABLED|IRQ_INPROGRESS)))
  55                 enable_r4030_irq(irq);
  56 }
  57
  58 static struct irq_chip r4030_irq_type = {
  59         .typename = "R4030",
  60         .startup = startup_r4030_irq,
  61         .shutdown = shutdown_r4030_irq,
  62         .enable = enable_r4030_irq,
  63         .disable = disable_r4030_irq,
  64         .ack = mask_and_ack_r4030_irq,
  65         .end = end_r4030_irq,
  66 };
  67
  68 void __init init_r4030_ints(void)
  69 {
  70         int i;
  71
  72         for (i = JAZZ_PARALLEL_IRQ; i <= JAZZ_TIMER_IRQ; i++) {
  73                 irq_desc[i].status     = IRQ_DISABLED;
  74                 irq_desc[i].action     = 0;
  75                 irq_desc[i].depth      = 1;
  76                 irq_desc[i].chip    = &r4030_irq_type;
  77         }
  78
  79         r4030_write_reg16(JAZZ_IO_IRQ_ENABLE, 0);
  80         r4030_read_reg16(JAZZ_IO_IRQ_SOURCE);           /* clear pending IRQs */
  81         r4030_read_reg32(JAZZ_R4030_INVAL_ADDR);        /* clear error bits */
  82 }
  83
  84 /*
  85  * On systems with i8259-style interrupt controllers we assume for
  86  * driver compatibility reasons interrupts 0 - 15 to be the i8259
  87  * interrupts even if the hardware uses a different interrupt numbering.
  88  */
  89 void __init arch_init_irq(void)
  90 {
  91         init_i8259_irqs();                      /* Integrated i8259  */
  92         init_r4030_ints();
  93
  94         change_c0_status(ST0_IM, IE_IRQ4 | IE_IRQ3 | IE_IRQ2 | IE_IRQ1);
  95 }
  96
  97 static void loc_call(unsigned int irq, unsigned int mask)
  98 {
  99         r4030_write_reg16(JAZZ_IO_IRQ_ENABLE,
 100                           r4030_read_reg16(JAZZ_IO_IRQ_ENABLE) & mask);
 101         do_IRQ(irq);
 102         r4030_write_reg16(JAZZ_IO_IRQ_ENABLE,
 103                           r4030_read_reg16(JAZZ_IO_IRQ_ENABLE) | mask);
 104 }
 105
 106 static void ll_local_dev(void)
 107 {
 108         switch (r4030_read_reg32(JAZZ_IO_IRQ_SOURCE)) {
 109         case 0:
 110                 panic("Unimplemented loc_no_irq handler");
 111                 break;
 112         case 4:
 113                 loc_call(JAZZ_PARALLEL_IRQ, JAZZ_IE_PARALLEL);
 114                 break;
 115         case 8:
 116                 loc_call(JAZZ_PARALLEL_IRQ, JAZZ_IE_FLOPPY);
 117                 break;
 118         case 12:
 119                 panic("Unimplemented loc_sound handler");
 120                 break;
 121         case 16:
 122                 panic("Unimplemented loc_video handler");
 123                 break;
 124         case 20:
 125                 loc_call(JAZZ_ETHERNET_IRQ, JAZZ_IE_ETHERNET);
 126                 break;
 127         case 24:
 128                 loc_call(JAZZ_SCSI_IRQ, JAZZ_IE_SCSI);
 129                 break;
 130         case 28:
 131                 loc_call(JAZZ_KEYBOARD_IRQ, JAZZ_IE_KEYBOARD);
 132                 break;
 133         case 32:
 134                 loc_call(JAZZ_MOUSE_IRQ, JAZZ_IE_MOUSE);
 135                 break;
 136         case 36:
 137                 loc_call(JAZZ_SERIAL1_IRQ, JAZZ_IE_SERIAL1);
 138                 break;
 139         case 40:
 140                 loc_call(JAZZ_SERIAL2_IRQ, JAZZ_IE_SERIAL2);
 141                 break;
 142         }
 143 }
 144
 145 asmlinkage void plat_irq_dispatch(void)
 146 {
 147         unsigned int pending = read_c0_cause() & read_c0_status() & ST0_IM;
 148
 149         if (pending & IE_IRQ5)
 150                 write_c0_compare(0);
 151         else if (pending & IE_IRQ4) {
 152                 r4030_read_reg32(JAZZ_TIMER_REGISTER);
 153                 do_IRQ(JAZZ_TIMER_IRQ);
 154         } else if (pending & IE_IRQ3)
 155                 panic("Unimplemented ISA NMI handler");
 156         else if (pending & IE_IRQ2)
 157                 do_IRQ(r4030_read_reg32(JAZZ_EISA_IRQ_ACK));
 158         else if (pending & IE_IRQ1) {
 159                 ll_local_dev();
 160         } else if (unlikely(pending & IE_IRQ0))
 161                 panic("Unimplemented local_dma handler");
 162         else if (pending & IE_SW1) {
 163                 clear_c0_cause(IE_SW1);
 164                 panic("Unimplemented sw1 handler");
 165         } else if (pending & IE_SW0) {
 166                 clear_c0_cause(IE_SW0);
 167                 panic("Unimplemented sw0 handler");
 168         }
 169 }