xref: /openbmc/qemu/hw/intc/etraxfs_pic.c (revision 9121d02c)
1 /*
2  * QEMU ETRAX Interrupt Controller.
3  *
4  * Copyright (c) 2008 Edgar E. Iglesias, Axis Communications AB.
5  *
6  * Permission is hereby granted, free of charge, to any person obtaining a copy
7  * of this software and associated documentation files (the "Software"), to deal
8  * in the Software without restriction, including without limitation the rights
9  * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
10  * copies of the Software, and to permit persons to whom the Software is
11  * furnished to do so, subject to the following conditions:
12  *
13  * The above copyright notice and this permission notice shall be included in
14  * all copies or substantial portions of the Software.
15  *
16  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
17  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
18  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
19  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
20  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
21  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
22  * THE SOFTWARE.
23  */
24 
25 #include "hw/sysbus.h"
26 #include "hw/hw.h"
27 //#include "pc.h"
28 //#include "etraxfs.h"
29 
30 #define D(x)
31 
32 #define R_RW_MASK   0
33 #define R_R_VECT    1
34 #define R_R_MASKED_VECT 2
35 #define R_R_NMI     3
36 #define R_R_GURU    4
37 #define R_MAX       5
38 
39 struct etrax_pic
40 {
41     SysBusDevice busdev;
42     MemoryRegion mmio;
43     void *interrupt_vector;
44     qemu_irq parent_irq;
45     qemu_irq parent_nmi;
46     uint32_t regs[R_MAX];
47 };
48 
49 static void pic_update(struct etrax_pic *fs)
50 {
51     uint32_t vector = 0;
52     int i;
53 
54     fs->regs[R_R_MASKED_VECT] = fs->regs[R_R_VECT] & fs->regs[R_RW_MASK];
55 
56     /* The ETRAX interrupt controller signals interrupts to the core
57        through an interrupt request wire and an irq vector bus. If
58        multiple interrupts are simultaneously active it chooses vector
59        0x30 and lets the sw choose the priorities.  */
60     if (fs->regs[R_R_MASKED_VECT]) {
61         uint32_t mv = fs->regs[R_R_MASKED_VECT];
62         for (i = 0; i < 31; i++) {
63             if (mv & 1) {
64                 vector = 0x31 + i;
65                 /* Check for multiple interrupts.  */
66                 if (mv > 1)
67                     vector = 0x30;
68                 break;
69             }
70             mv >>= 1;
71         }
72     }
73 
74     if (fs->interrupt_vector) {
75         /* hack alert: ptr property */
76         *(uint32_t*)(fs->interrupt_vector) = vector;
77     }
78     qemu_set_irq(fs->parent_irq, !!vector);
79 }
80 
81 static uint64_t
82 pic_read(void *opaque, hwaddr addr, unsigned int size)
83 {
84     struct etrax_pic *fs = opaque;
85     uint32_t rval;
86 
87     rval = fs->regs[addr >> 2];
88     D(printf("%s %x=%x\n", __func__, addr, rval));
89     return rval;
90 }
91 
92 static void pic_write(void *opaque, hwaddr addr,
93                       uint64_t value, unsigned int size)
94 {
95     struct etrax_pic *fs = opaque;
96     D(printf("%s addr=%x val=%x\n", __func__, addr, value));
97 
98     if (addr == R_RW_MASK) {
99         fs->regs[R_RW_MASK] = value;
100         pic_update(fs);
101     }
102 }
103 
104 static const MemoryRegionOps pic_ops = {
105     .read = pic_read,
106     .write = pic_write,
107     .endianness = DEVICE_NATIVE_ENDIAN,
108     .valid = {
109         .min_access_size = 4,
110         .max_access_size = 4
111     }
112 };
113 
114 static void nmi_handler(void *opaque, int irq, int level)
115 {
116     struct etrax_pic *fs = (void *)opaque;
117     uint32_t mask;
118 
119     mask = 1 << irq;
120     if (level)
121         fs->regs[R_R_NMI] |= mask;
122     else
123         fs->regs[R_R_NMI] &= ~mask;
124 
125     qemu_set_irq(fs->parent_nmi, !!fs->regs[R_R_NMI]);
126 }
127 
128 static void irq_handler(void *opaque, int irq, int level)
129 {
130     struct etrax_pic *fs = (void *)opaque;
131 
132     if (irq >= 30)
133         return nmi_handler(opaque, irq, level);
134 
135     irq -= 1;
136     fs->regs[R_R_VECT] &= ~(1 << irq);
137     fs->regs[R_R_VECT] |= (!!level << irq);
138     pic_update(fs);
139 }
140 
141 static int etraxfs_pic_init(SysBusDevice *dev)
142 {
143     struct etrax_pic *s = FROM_SYSBUS(typeof (*s), dev);
144 
145     qdev_init_gpio_in(&dev->qdev, irq_handler, 32);
146     sysbus_init_irq(dev, &s->parent_irq);
147     sysbus_init_irq(dev, &s->parent_nmi);
148 
149     memory_region_init_io(&s->mmio, OBJECT(s), &pic_ops, s,
150                           "etraxfs-pic", R_MAX * 4);
151     sysbus_init_mmio(dev, &s->mmio);
152     return 0;
153 }
154 
155 static Property etraxfs_pic_properties[] = {
156     DEFINE_PROP_PTR("interrupt_vector", struct etrax_pic, interrupt_vector),
157     DEFINE_PROP_END_OF_LIST(),
158 };
159 
160 static void etraxfs_pic_class_init(ObjectClass *klass, void *data)
161 {
162     DeviceClass *dc = DEVICE_CLASS(klass);
163     SysBusDeviceClass *k = SYS_BUS_DEVICE_CLASS(klass);
164 
165     k->init = etraxfs_pic_init;
166     dc->props = etraxfs_pic_properties;
167 }
168 
169 static const TypeInfo etraxfs_pic_info = {
170     .name          = "etraxfs,pic",
171     .parent        = TYPE_SYS_BUS_DEVICE,
172     .instance_size = sizeof(struct etrax_pic),
173     .class_init    = etraxfs_pic_class_init,
174 };
175 
176 static void etraxfs_pic_register_types(void)
177 {
178     type_register_static(&etraxfs_pic_info);
179 }
180 
181 type_init(etraxfs_pic_register_types)
182