4 * This file is subject to the terms and conditions of the GNU General Public
5 * License. See the file "COPYING" in the main directory of this archive
8 * Copyright (C) 1995, 1996, 1997, 2003 by Ralf Baechle
10 #include <linux/kernel.h>
11 #include <linux/init.h>
12 #include <linux/irq.h>
13 #include <linux/interrupt.h>
14 #include <linux/pci.h>
16 #include <asm/i8259.h>
17 #include <asm/irq_cpu.h>
18 #include <asm/gt64120.h>
20 #include <asm/mach-cobalt/cobalt.h>
23 * We have two types of interrupts that we handle, ones that come in through
24 * the CPU interrupt lines, and ones that come in on the via chip. The CPU
27 * 16 - Software interrupt 0 (unused) IE_SW0
28 * 17 - Software interrupt 1 (unused) IE_SW1
29 * 18 - Galileo chip (timer) IE_IRQ0
30 * 19 - Tulip 0 + NCR SCSI IE_IRQ1
31 * 20 - Tulip 1 IE_IRQ2
32 * 21 - 16550 UART IE_IRQ3
33 * 22 - VIA southbridge PIC IE_IRQ4
36 * The VIA chip is a master/slave 8259 setup and has the following interrupts:
44 static inline void galileo_irq(void)
46 unsigned int mask
, pending
, devfn
;
48 mask
= GALILEO_INL(GT_INTRMASK_OFS
);
49 pending
= GALILEO_INL(GT_INTRCAUSE_OFS
) & mask
;
51 if (pending
& GALILEO_INTR_T0EXP
) {
53 GALILEO_OUTL(~GALILEO_INTR_T0EXP
, GT_INTRCAUSE_OFS
);
54 do_IRQ(COBALT_GALILEO_IRQ
);
56 } else if (pending
& GALILEO_INTR_RETRY_CTR
) {
58 devfn
= GALILEO_INL(GT_PCI0_CFGADDR_OFS
) >> 8;
59 GALILEO_OUTL(~GALILEO_INTR_RETRY_CTR
, GT_INTRCAUSE_OFS
);
60 printk(KERN_WARNING
"Galileo: PCI retry count exceeded (%02x.%u)\n",
61 PCI_SLOT(devfn
), PCI_FUNC(devfn
));
65 GALILEO_OUTL(mask
& ~pending
, GT_INTRMASK_OFS
);
66 printk(KERN_WARNING
"Galileo: masking unexpected interrupt %08x\n", pending
);
70 static inline void via_pic_irq(void)
79 asmlinkage
void plat_irq_dispatch(void)
81 unsigned pending
= read_c0_status() & read_c0_cause();
83 if (pending
& CAUSEF_IP2
) /* COBALT_GALILEO_IRQ (18) */
85 else if (pending
& CAUSEF_IP6
) /* COBALT_VIA_IRQ (22) */
87 else if (pending
& CAUSEF_IP3
) /* COBALT_ETH0_IRQ (19) */
88 do_IRQ(COBALT_CPU_IRQ
+ 3);
89 else if (pending
& CAUSEF_IP4
) /* COBALT_ETH1_IRQ (20) */
90 do_IRQ(COBALT_CPU_IRQ
+ 4);
91 else if (pending
& CAUSEF_IP5
) /* COBALT_SERIAL_IRQ (21) */
92 do_IRQ(COBALT_CPU_IRQ
+ 5);
93 else if (pending
& CAUSEF_IP7
) /* IRQ 23 */
94 do_IRQ(COBALT_CPU_IRQ
+ 7);
97 static struct irqaction irq_via
= {
98 no_action
, 0, { { 0, } }, "cascade", NULL
, NULL
101 void __init
arch_init_irq(void)
104 * Mask all Galileo interrupts. The Galileo
105 * handler is set in cobalt_timer_setup()
107 GALILEO_OUTL(0, GT_INTRMASK_OFS
);
109 init_i8259_irqs(); /* 0 ... 15 */
110 mips_cpu_irq_init(COBALT_CPU_IRQ
); /* 16 ... 23 */
113 * Mask all cpu interrupts
114 * (except IE4, we already masked those at VIA level)
116 change_c0_status(ST0_IM
, IE_IRQ4
);
118 setup_irq(COBALT_VIA_IRQ
, &irq_via
);