tjh.dev
Linux kernel mirror (for testing)
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linux
1/*
2 *
3 * Copyright (c) 1999 Grant Erickson <grant@lcse.umn.edu>
4 *
5 * Module name: ppc403_pic.c
6 *
7 * Description:
8 * Interrupt controller driver for PowerPC 403-based processors.
9 */
10
11/*
12 * The PowerPC 403 cores' Asynchronous Interrupt Controller (AIC) has
13 * 32 possible interrupts, a majority of which are not implemented on
14 * all cores. There are six configurable, external interrupt pins and
15 * there are eight internal interrupts for the on-chip serial port
16 * (SPU), DMA controller, and JTAG controller.
17 *
18 */
19
20#include <linux/init.h>
21#include <linux/sched.h>
22#include <linux/signal.h>
23#include <linux/stddef.h>
24
25#include <asm/processor.h>
26#include <asm/system.h>
27#include <asm/irq.h>
28#include <asm/ppc4xx_pic.h>
29
30/* Function Prototypes */
31
32static void ppc403_aic_enable(unsigned int irq);
33static void ppc403_aic_disable(unsigned int irq);
34static void ppc403_aic_disable_and_ack(unsigned int irq);
35
36static struct hw_interrupt_type ppc403_aic = {
37 "403GC AIC",
38 NULL,
39 NULL,
40 ppc403_aic_enable,
41 ppc403_aic_disable,
42 ppc403_aic_disable_and_ack,
43 0
44};
45
46int
47ppc403_pic_get_irq(struct pt_regs *regs)
48{
49 int irq;
50 unsigned long bits;
51
52 /*
53 * Only report the status of those interrupts that are actually
54 * enabled.
55 */
56
57 bits = mfdcr(DCRN_EXISR) & mfdcr(DCRN_EXIER);
58
59 /*
60 * Walk through the interrupts from highest priority to lowest, and
61 * report the first pending interrupt found.
62 * We want PPC, not C bit numbering, so just subtract the ffs()
63 * result from 32.
64 */
65 irq = 32 - ffs(bits);
66
67 if (irq == NR_AIC_IRQS)
68 irq = -1;
69
70 return (irq);
71}
72
73static void
74ppc403_aic_enable(unsigned int irq)
75{
76 int bit, word;
77
78 bit = irq & 0x1f;
79 word = irq >> 5;
80
81 ppc_cached_irq_mask[word] |= (1 << (31 - bit));
82 mtdcr(DCRN_EXIER, ppc_cached_irq_mask[word]);
83}
84
85static void
86ppc403_aic_disable(unsigned int irq)
87{
88 int bit, word;
89
90 bit = irq & 0x1f;
91 word = irq >> 5;
92
93 ppc_cached_irq_mask[word] &= ~(1 << (31 - bit));
94 mtdcr(DCRN_EXIER, ppc_cached_irq_mask[word]);
95}
96
97static void
98ppc403_aic_disable_and_ack(unsigned int irq)
99{
100 int bit, word;
101
102 bit = irq & 0x1f;
103 word = irq >> 5;
104
105 ppc_cached_irq_mask[word] &= ~(1 << (31 - bit));
106 mtdcr(DCRN_EXIER, ppc_cached_irq_mask[word]);
107 mtdcr(DCRN_EXISR, (1 << (31 - bit)));
108}
109
110void __init
111ppc4xx_pic_init(void)
112{
113 int i;
114
115 /*
116 * Disable all external interrupts until they are
117 * explicity requested.
118 */
119 ppc_cached_irq_mask[0] = 0;
120
121 mtdcr(DCRN_EXIER, ppc_cached_irq_mask[0]);
122
123 ppc_md.get_irq = ppc403_pic_get_irq;
124
125 for (i = 0; i < NR_IRQS; i++)
126 irq_desc[i].handler = &ppc403_aic;
127}