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 void disable_r4030_irq(unsigned int irq)
  32 {
  33         unsigned int mask = ~(1 << (irq - JAZZ_PARALLEL_IRQ));
  34         unsigned long flags;
  35
  36         spin_lock_irqsave(&r4030_lock, flags);
  37         mask &= r4030_read_reg16(JAZZ_IO_IRQ_ENABLE);
  38         r4030_write_reg16(JAZZ_IO_IRQ_ENABLE, mask);
  39         spin_unlock_irqrestore(&r4030_lock, flags);
  40 }
  41
  42 static void end_r4030_irq(unsigned int irq)
  43 {
  44         if (!(irq_desc[irq].status & (IRQ_DISABLED|IRQ_INPROGRESS)))
  45                 enable_r4030_irq(irq);
  46 }
  47
  48 static struct irq_chip r4030_irq_type = {
  49         .typename = "R4030",
  50         .ack = disable_r4030_irq,
  51         .mask = disable_r4030_irq,
  52         .mask_ack = disable_r4030_irq,
  53         .unmask = enable_r4030_irq,
  54         .end = end_r4030_irq,
  55 };
  56
  57 void __init init_r4030_ints(void)
  58 {
  59         int i;
  60
  61         for (i = JAZZ_PARALLEL_IRQ; i <= JAZZ_TIMER_IRQ; i++)
  62                 set_irq_chip_and_handler(i, &r4030_irq_type, handle_level_irq);
  63
  64         r4030_write_reg16(JAZZ_IO_IRQ_ENABLE, 0);
  65         r4030_read_reg16(JAZZ_IO_IRQ_SOURCE);           /* clear pending IRQs */
  66         r4030_read_reg32(JAZZ_R4030_INVAL_ADDR);        /* clear error bits */
  67 }
  68
  69 /*
  70  * On systems with i8259-style interrupt controllers we assume for
  71  * driver compatibility reasons interrupts 0 - 15 to be the i8259
  72  * interrupts even if the hardware uses a different interrupt numbering.
  73  */
  74 void __init arch_init_irq(void)
  75 {
  76         init_i8259_irqs();                      /* Integrated i8259  */
  77         init_r4030_ints();
  78
  79         change_c0_status(ST0_IM, IE_IRQ4 | IE_IRQ3 | IE_IRQ2 | IE_IRQ1);
  80 }
  81
  82 static void loc_call(unsigned int irq, unsigned int mask)
  83 {
  84         r4030_write_reg16(JAZZ_IO_IRQ_ENABLE,
  85                           r4030_read_reg16(JAZZ_IO_IRQ_ENABLE) & mask);
  86         do_IRQ(irq);
  87         r4030_write_reg16(JAZZ_IO_IRQ_ENABLE,
  88                           r4030_read_reg16(JAZZ_IO_IRQ_ENABLE) | mask);
  89 }
  90
  91 static void ll_local_dev(void)
  92 {
  93         switch (r4030_read_reg32(JAZZ_IO_IRQ_SOURCE)) {
  94         case 0:
  95                 panic("Unimplemented loc_no_irq handler");
  96                 break;
  97         case 4:
  98                 loc_call(JAZZ_PARALLEL_IRQ, JAZZ_IE_PARALLEL);
  99                 break;
 100         case 8:
 101                 loc_call(JAZZ_PARALLEL_IRQ, JAZZ_IE_FLOPPY);
 102                 break;
 103         case 12:
 104                 panic("Unimplemented loc_sound handler");
 105                 break;
 106         case 16:
 107                 panic("Unimplemented loc_video handler");
 108                 break;
 109         case 20:
 110                 loc_call(JAZZ_ETHERNET_IRQ, JAZZ_IE_ETHERNET);
 111                 break;
 112         case 24:
 113                 loc_call(JAZZ_SCSI_IRQ, JAZZ_IE_SCSI);
 114                 break;
 115         case 28:
 116                 loc_call(JAZZ_KEYBOARD_IRQ, JAZZ_IE_KEYBOARD);
 117                 break;
 118         case 32:
 119                 loc_call(JAZZ_MOUSE_IRQ, JAZZ_IE_MOUSE);
 120                 break;
 121         case 36:
 122                 loc_call(JAZZ_SERIAL1_IRQ, JAZZ_IE_SERIAL1);
 123                 break;
 124         case 40:
 125                 loc_call(JAZZ_SERIAL2_IRQ, JAZZ_IE_SERIAL2);
 126                 break;
 127         }
 128 }
 129
 130 asmlinkage void plat_irq_dispatch(void)
 131 {
 132         unsigned int pending = read_c0_cause() & read_c0_status() & ST0_IM;
 133
 134         if (pending & IE_IRQ5)
 135                 write_c0_compare(0);
 136         else if (pending & IE_IRQ4) {
 137                 r4030_read_reg32(JAZZ_TIMER_REGISTER);
 138                 do_IRQ(JAZZ_TIMER_IRQ);
 139         } else if (pending & IE_IRQ3)
 140                 panic("Unimplemented ISA NMI handler");
 141         else if (pending & IE_IRQ2)
 142                 do_IRQ(r4030_read_reg32(JAZZ_EISA_IRQ_ACK));
 143         else if (pending & IE_IRQ1) {
 144                 ll_local_dev();
 145         } else if (unlikely(pending & IE_IRQ0))
 146                 panic("Unimplemented local_dma handler");
 147         else if (pending & IE_SW1) {
 148                 clear_c0_cause(IE_SW1);
 149                 panic("Unimplemented sw1 handler");
 150         } else if (pending & IE_SW0) {
 151                 clear_c0_cause(IE_SW0);
 152                 panic("Unimplemented sw0 handler");
 153         }
 154 }