xref: /openbmc/linux/arch/mips/jazz/irq.c (revision 1da177e4)
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 extern asmlinkage void jazz_handle_int(void);
19 
20 static DEFINE_SPINLOCK(r4030_lock);
21 
22 static void enable_r4030_irq(unsigned int irq)
23 {
24 	unsigned int mask = 1 << (irq - JAZZ_PARALLEL_IRQ);
25 	unsigned long flags;
26 
27 	spin_lock_irqsave(&r4030_lock, flags);
28 	mask |= r4030_read_reg16(JAZZ_IO_IRQ_ENABLE);
29 	r4030_write_reg16(JAZZ_IO_IRQ_ENABLE, mask);
30 	spin_unlock_irqrestore(&r4030_lock, flags);
31 }
32 
33 static unsigned int startup_r4030_irq(unsigned int irq)
34 {
35 	enable_r4030_irq(irq);
36 	return 0; /* never anything pending */
37 }
38 
39 #define shutdown_r4030_irq	disable_r4030_irq
40 
41 void disable_r4030_irq(unsigned int irq)
42 {
43 	unsigned int mask = ~(1 << (irq - JAZZ_PARALLEL_IRQ));
44 	unsigned long flags;
45 
46 	spin_lock_irqsave(&r4030_lock, flags);
47 	mask &= r4030_read_reg16(JAZZ_IO_IRQ_ENABLE);
48 	r4030_write_reg16(JAZZ_IO_IRQ_ENABLE, mask);
49 	spin_unlock_irqrestore(&r4030_lock, flags);
50 }
51 
52 #define mask_and_ack_r4030_irq disable_r4030_irq
53 
54 static void end_r4030_irq(unsigned int irq)
55 {
56 	if (!(irq_desc[irq].status & (IRQ_DISABLED|IRQ_INPROGRESS)))
57 		enable_r4030_irq(irq);
58 }
59 
60 static struct hw_interrupt_type r4030_irq_type = {
61 	"R4030",
62 	startup_r4030_irq,
63 	shutdown_r4030_irq,
64 	enable_r4030_irq,
65 	disable_r4030_irq,
66 	mask_and_ack_r4030_irq,
67 	end_r4030_irq,
68 	NULL
69 };
70 
71 void __init init_r4030_ints(void)
72 {
73 	int i;
74 
75 	for (i = JAZZ_PARALLEL_IRQ; i <= JAZZ_TIMER_IRQ; i++) {
76 		irq_desc[i].status     = IRQ_DISABLED;
77 		irq_desc[i].action     = 0;
78 		irq_desc[i].depth      = 1;
79 		irq_desc[i].handler    = &r4030_irq_type;
80 	}
81 
82 	r4030_write_reg16(JAZZ_IO_IRQ_ENABLE, 0);
83 	r4030_read_reg16(JAZZ_IO_IRQ_SOURCE);		/* clear pending IRQs */
84 	r4030_read_reg32(JAZZ_R4030_INVAL_ADDR);	/* clear error bits */
85 }
86 
87 /*
88  * On systems with i8259-style interrupt controllers we assume for
89  * driver compatibility reasons interrupts 0 - 15 to be the i8259
90  * interrupts even if the hardware uses a different interrupt numbering.
91  */
92 void __init arch_init_irq(void)
93 {
94 	set_except_vector(0, jazz_handle_int);
95 
96 	init_i8259_irqs();			/* Integrated i8259  */
97 	init_r4030_ints();
98 
99 	change_c0_status(ST0_IM, IE_IRQ4 | IE_IRQ3 | IE_IRQ2 | IE_IRQ1);
100 }
101