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1 | /* irq-mb93091.c: MB93091 FPGA interrupt handling | |
2 | * | |
3 | * Copyright (C) 2003 Red Hat, Inc. All Rights Reserved. | |
4 | * Written by David Howells (dhowells@redhat.com) | |
5 | * | |
6 | * This program is free software; you can redistribute it and/or | |
7 | * modify it under the terms of the GNU General Public License | |
8 | * as published by the Free Software Foundation; either version | |
9 | * 2 of the License, or (at your option) any later version. | |
10 | */ | |
11 | ||
12 | #include <linux/ptrace.h> | |
13 | #include <linux/errno.h> | |
14 | #include <linux/signal.h> | |
15 | #include <linux/sched.h> | |
16 | #include <linux/ioport.h> | |
17 | #include <linux/interrupt.h> | |
18 | #include <linux/init.h> | |
19 | #include <linux/irq.h> | |
20 | #include <linux/bitops.h> | |
21 | ||
22 | #include <asm/io.h> | |
23 | #include <asm/delay.h> | |
24 | #include <asm/irq.h> | |
25 | #include <asm/irc-regs.h> | |
26 | ||
27 | #define __reg16(ADDR) (*(volatile unsigned short *)(ADDR)) | |
28 | ||
29 | #define __get_IMR() ({ __reg16(0xffc00004); }) | |
30 | #define __set_IMR(M) do { __reg16(0xffc00004) = (M); wmb(); } while(0) | |
31 | #define __get_IFR() ({ __reg16(0xffc0000c); }) | |
32 | #define __clr_IFR(M) do { __reg16(0xffc0000c) = ~(M); wmb(); } while(0) | |
33 | ||
34 | ||
35 | /* | |
36 | * on-motherboard FPGA PIC operations | |
37 | */ | |
38 | static void frv_fpga_mask(struct irq_data *d) | |
39 | { | |
40 | uint16_t imr = __get_IMR(); | |
41 | ||
42 | imr |= 1 << (d->irq - IRQ_BASE_FPGA); | |
43 | ||
44 | __set_IMR(imr); | |
45 | } | |
46 | ||
47 | static void frv_fpga_ack(struct irq_data *d) | |
48 | { | |
49 | __clr_IFR(1 << (d->irq - IRQ_BASE_FPGA)); | |
50 | } | |
51 | ||
52 | static void frv_fpga_mask_ack(struct irq_data *d) | |
53 | { | |
54 | uint16_t imr = __get_IMR(); | |
55 | ||
56 | imr |= 1 << (d->irq - IRQ_BASE_FPGA); | |
57 | __set_IMR(imr); | |
58 | ||
59 | __clr_IFR(1 << (d->irq - IRQ_BASE_FPGA)); | |
60 | } | |
61 | ||
62 | static void frv_fpga_unmask(struct irq_data *d) | |
63 | { | |
64 | uint16_t imr = __get_IMR(); | |
65 | ||
66 | imr &= ~(1 << (d->irq - IRQ_BASE_FPGA)); | |
67 | ||
68 | __set_IMR(imr); | |
69 | } | |
70 | ||
71 | static struct irq_chip frv_fpga_pic = { | |
72 | .name = "mb93091", | |
73 | .irq_ack = frv_fpga_ack, | |
74 | .irq_mask = frv_fpga_mask, | |
75 | .irq_mask_ack = frv_fpga_mask_ack, | |
76 | .irq_unmask = frv_fpga_unmask, | |
77 | }; | |
78 | ||
79 | /* | |
80 | * FPGA PIC interrupt handler | |
81 | */ | |
82 | static irqreturn_t fpga_interrupt(int irq, void *_mask) | |
83 | { | |
84 | uint16_t imr, mask = (unsigned long) _mask; | |
85 | ||
86 | imr = __get_IMR(); | |
87 | mask = mask & ~imr & __get_IFR(); | |
88 | ||
89 | /* poll all the triggered IRQs */ | |
90 | while (mask) { | |
91 | int irq; | |
92 | ||
93 | asm("scan %1,gr0,%0" : "=r"(irq) : "r"(mask)); | |
94 | irq = 31 - irq; | |
95 | mask &= ~(1 << irq); | |
96 | ||
97 | generic_handle_irq(IRQ_BASE_FPGA + irq); | |
98 | } | |
99 | ||
100 | return IRQ_HANDLED; | |
101 | } | |
102 | ||
103 | /* | |
104 | * define an interrupt action for each FPGA PIC output | |
105 | * - use dev_id to indicate the FPGA PIC input to output mappings | |
106 | */ | |
107 | static struct irqaction fpga_irq[4] = { | |
108 | [0] = { | |
109 | .handler = fpga_interrupt, | |
110 | .flags = IRQF_SHARED, | |
111 | .name = "fpga.0", | |
112 | .dev_id = (void *) 0x0028UL, | |
113 | }, | |
114 | [1] = { | |
115 | .handler = fpga_interrupt, | |
116 | .flags = IRQF_SHARED, | |
117 | .name = "fpga.1", | |
118 | .dev_id = (void *) 0x0050UL, | |
119 | }, | |
120 | [2] = { | |
121 | .handler = fpga_interrupt, | |
122 | .flags = IRQF_SHARED, | |
123 | .name = "fpga.2", | |
124 | .dev_id = (void *) 0x1c00UL, | |
125 | }, | |
126 | [3] = { | |
127 | .handler = fpga_interrupt, | |
128 | .flags = IRQF_SHARED, | |
129 | .name = "fpga.3", | |
130 | .dev_id = (void *) 0x6386UL, | |
131 | } | |
132 | }; | |
133 | ||
134 | /* | |
135 | * initialise the motherboard FPGA's PIC | |
136 | */ | |
137 | void __init fpga_init(void) | |
138 | { | |
139 | int irq; | |
140 | ||
141 | /* all PIC inputs are all set to be low-level driven, apart from the | |
142 | * NMI button (15) which is fixed at falling-edge | |
143 | */ | |
144 | __set_IMR(0x7ffe); | |
145 | __clr_IFR(0x0000); | |
146 | ||
147 | for (irq = IRQ_BASE_FPGA + 1; irq <= IRQ_BASE_FPGA + 14; irq++) | |
148 | irq_set_chip_and_handler(irq, &frv_fpga_pic, handle_level_irq); | |
149 | ||
150 | irq_set_chip_and_handler(IRQ_FPGA_NMI, &frv_fpga_pic, handle_edge_irq); | |
151 | ||
152 | /* the FPGA drives the first four external IRQ inputs on the CPU PIC */ | |
153 | setup_irq(IRQ_CPU_EXTERNAL0, &fpga_irq[0]); | |
154 | setup_irq(IRQ_CPU_EXTERNAL1, &fpga_irq[1]); | |
155 | setup_irq(IRQ_CPU_EXTERNAL2, &fpga_irq[2]); | |
156 | setup_irq(IRQ_CPU_EXTERNAL3, &fpga_irq[3]); | |
157 | } |