1 /*
2 * intc.c -- support for the old ColdFire interrupt controller
3 *
4 * (C) Copyright 2009, Greg Ungerer <gerg@snapgear.com>
5 *
6 * This file is subject to the terms and conditions of the GNU General Public
7 * License. See the file COPYING in the main directory of this archive
8 * for more details.
9 */
10
11 #include <linux/types.h>
12 #include <linux/init.h>
13 #include <linux/kernel.h>
14 #include <linux/interrupt.h>
15 #include <linux/irq.h>
16 #include <linux/io.h>
17 #include <asm/traps.h>
18 #include <asm/coldfire.h>
19 #include <asm/mcfsim.h>
20
21 /*
22 * The mapping of irq number to a mask register bit is not one-to-one.
23 * The irq numbers are either based on "level" of interrupt or fixed
24 * for an autovector-able interrupt. So we keep a local data structure
25 * that maps from irq to mask register. Not all interrupts will have
26 * an IMR bit.
27 */
28 unsigned char mcf_irq2imr[NR_IRQS];
29
30 /*
31 * Define the minimum and maximum external interrupt numbers.
32 * This is also used as the "level" interrupt numbers.
33 */
34 #define EIRQ1 25
35 #define EIRQ7 31
36
37 /*
38 * In the early version 2 core ColdFire parts the IMR register was 16 bits
39 * in size. Version 3 (and later version 2) core parts have a 32 bit
40 * sized IMR register. Provide some size independent methods to access the
41 * IMR register.
42 */
43 #ifdef MCFSIM_IMR_IS_16BITS
44
45 void mcf_setimr(int index)
46 {
47 u16 imr;
48 imr = __raw_readw(MCFSIM_IMR);
49 __raw_writew(imr | (0x1 << index), MCFSIM_IMR);
50 }
51
52 void mcf_clrimr(int index)
53 {
54 u16 imr;
55 imr = __raw_readw(MCFSIM_IMR);
56 __raw_writew(imr & ~(0x1 << index), MCFSIM_IMR);
57 }
58
59 static void mcf_maskimr(unsigned int mask)
60 {
61 u16 imr;
62 imr = __raw_readw(MCFSIM_IMR);
63 imr |= mask;
64 __raw_writew(imr, MCFSIM_IMR);
65 }
66
67 #else
68
69 void mcf_setimr(int index)
70 {
71 u32 imr;
72 imr = __raw_readl(MCFSIM_IMR);
73 __raw_writel(imr | (0x1 << index), MCFSIM_IMR);
74 }
75
76 void mcf_clrimr(int index)
77 {
78 u32 imr;
79 imr = __raw_readl(MCFSIM_IMR);
80 __raw_writel(imr & ~(0x1 << index), MCFSIM_IMR);
81 }
82
83 static void mcf_maskimr(unsigned int mask)
84 {
85 u32 imr;
86 imr = __raw_readl(MCFSIM_IMR);
87 imr |= mask;
88 __raw_writel(imr, MCFSIM_IMR);
89 }
90
91 #endif
92
93 /*
94 * Interrupts can be "vectored" on the ColdFire cores that support this old
95 * interrupt controller. That is, the device raising the interrupt can also
96 * supply the vector number to interrupt through. The AVR register of the
97 * interrupt controller enables or disables this for each external interrupt,
98 * so provide generic support for this. Setting this up is out-of-band for
99 * the interrupt system API's, and needs to be done by the driver that
100 * supports this device. Very few devices actually use this.
101 */
102 void mcf_autovector(int irq)
103 {
104 #ifdef MCFSIM_AVR
105 if ((irq >= EIRQ1) && (irq <= EIRQ7)) {
106 u8 avec;
107 avec = __raw_readb(MCFSIM_AVR);
108 avec |= (0x1 << (irq - EIRQ1 + 1));
109 __raw_writeb(avec, MCFSIM_AVR);
110 }
111 #endif
112 }
113
114 static void intc_irq_mask(struct irq_data *d)
115 {
116 if (mcf_irq2imr[d->irq])
117 mcf_setimr(mcf_irq2imr[d->irq]);
118 }
119
120 static void intc_irq_unmask(struct irq_data *d)
121 {
122 if (mcf_irq2imr[d->irq])
123 mcf_clrimr(mcf_irq2imr[d->irq]);
124 }
125
126 static int intc_irq_set_type(struct irq_data *d, unsigned int type)
127 {
128 return 0;
129 }
130
131 static struct irq_chip intc_irq_chip = {
132 .name = "CF-INTC",
133 .irq_mask = intc_irq_mask,
134 .irq_unmask = intc_irq_unmask,
135 .irq_set_type = intc_irq_set_type,
136 };
137
138 void __init init_IRQ(void)
139 {
140 int irq;
141
142 mcf_maskimr(0xffffffff);
143
144 for (irq = 0; (irq < NR_IRQS); irq++) {
145 irq_set_chip(irq, &intc_irq_chip);
146 irq_set_irq_type(irq, IRQ_TYPE_LEVEL_HIGH);
147 irq_set_handler(irq, handle_level_irq);
148 }
149 }
150
151
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