1 // SPDX-License-Identifier: GPL-2.0+
2 //
3 // Copyright 2003-2005 Simtec Electronics
4 // Ben Dooks <ben@simtec.co.uk>
5 //
6 // http://www.simtec.co.uk/products/EB2410ITX/
7
8 #include <linux/init.h>
9 #include <linux/module.h>
10 #include <linux/ioport.h>
11 #include <linux/device.h>
12 #include <linux/io.h>
13
14 #include <asm/irq.h>
15 #include <asm/mach-types.h>
16 #include <asm/mach/irq.h>
17
18 #include <mach/hardware.h>
19 #include <mach/regs-irq.h>
20
21 #include "bast.h"
22
23 #define irqdbf(x...)
24 #define irqdbf2(x...)
25
26 /* handle PC104 ISA interrupts from the system CPLD */
27
28 /* table of ISA irq nos to the relevant mask... zero means
29 * the irq is not implemented
30 */
31 static const unsigned char bast_pc104_irqmasks[] = {
32 0, /* 0 */
33 0, /* 1 */
34 0, /* 2 */
35 1, /* 3 */
36 0, /* 4 */
37 2, /* 5 */
38 0, /* 6 */
39 4, /* 7 */
40 0, /* 8 */
41 0, /* 9 */
42 8, /* 10 */
43 0, /* 11 */
44 0, /* 12 */
45 0, /* 13 */
46 0, /* 14 */
47 0, /* 15 */
48 };
49
50 static const unsigned char bast_pc104_irqs[] = { 3, 5, 7, 10 };
51
52 static void
bast_pc104_mask(struct irq_data * data)53 bast_pc104_mask(struct irq_data *data)
54 {
55 unsigned long temp;
56
57 temp = __raw_readb(BAST_VA_PC104_IRQMASK);
58 temp &= ~bast_pc104_irqmasks[data->irq];
59 __raw_writeb(temp, BAST_VA_PC104_IRQMASK);
60 }
61
62 static void
bast_pc104_maskack(struct irq_data * data)63 bast_pc104_maskack(struct irq_data *data)
64 {
65 struct irq_desc *desc = irq_desc + BAST_IRQ_ISA;
66
67 bast_pc104_mask(data);
68 desc->irq_data.chip->irq_ack(&desc->irq_data);
69 }
70
71 static void
bast_pc104_unmask(struct irq_data * data)72 bast_pc104_unmask(struct irq_data *data)
73 {
74 unsigned long temp;
75
76 temp = __raw_readb(BAST_VA_PC104_IRQMASK);
77 temp |= bast_pc104_irqmasks[data->irq];
78 __raw_writeb(temp, BAST_VA_PC104_IRQMASK);
79 }
80
81 static struct irq_chip bast_pc104_chip = {
82 .irq_mask = bast_pc104_mask,
83 .irq_unmask = bast_pc104_unmask,
84 .irq_ack = bast_pc104_maskack
85 };
86
bast_irq_pc104_demux(struct irq_desc * desc)87 static void bast_irq_pc104_demux(struct irq_desc *desc)
88 {
89 unsigned int stat;
90 unsigned int irqno;
91 int i;
92
93 stat = __raw_readb(BAST_VA_PC104_IRQREQ) & 0xf;
94
95 if (unlikely(stat == 0)) {
96 /* ack if we get an irq with nothing (ie, startup) */
97
98 desc = irq_desc + BAST_IRQ_ISA;
99 desc->irq_data.chip->irq_ack(&desc->irq_data);
100 } else {
101 /* handle the IRQ */
102
103 for (i = 0; stat != 0; i++, stat >>= 1) {
104 if (stat & 1) {
105 irqno = bast_pc104_irqs[i];
106 generic_handle_irq(irqno);
107 }
108 }
109 }
110 }
111
bast_irq_init(void)112 static __init int bast_irq_init(void)
113 {
114 unsigned int i;
115
116 if (machine_is_bast()) {
117 printk(KERN_INFO "BAST PC104 IRQ routing, Copyright 2005 Simtec Electronics\n");
118
119 /* zap all the IRQs */
120
121 __raw_writeb(0x0, BAST_VA_PC104_IRQMASK);
122
123 irq_set_chained_handler(BAST_IRQ_ISA, bast_irq_pc104_demux);
124
125 /* register our IRQs */
126
127 for (i = 0; i < 4; i++) {
128 unsigned int irqno = bast_pc104_irqs[i];
129
130 irq_set_chip_and_handler(irqno, &bast_pc104_chip,
131 handle_level_irq);
132 irq_clear_status_flags(irqno, IRQ_NOREQUEST);
133 }
134 }
135
136 return 0;
137 }
138
139 arch_initcall(bast_irq_init);
140
