xref: /openbmc/qemu/hw/intc/etraxfs_pic.c (revision d5938f29)
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 "qemu/osdep.h"
26 #include "hw/sysbus.h"
27 #include "qemu/module.h"
28 #include "hw/irq.h"
29 #include "hw/qdev-properties.h"
30 //#include "pc.h"
31 //#include "etraxfs.h"
32 
33 #define D(x)
34 
35 #define R_RW_MASK   0
36 #define R_R_VECT    1
37 #define R_R_MASKED_VECT 2
38 #define R_R_NMI     3
39 #define R_R_GURU    4
40 #define R_MAX       5
41 
42 #define TYPE_ETRAX_FS_PIC "etraxfs,pic"
43 #define ETRAX_FS_PIC(obj) \
44     OBJECT_CHECK(struct etrax_pic, (obj), TYPE_ETRAX_FS_PIC)
45 
46 struct etrax_pic
47 {
48     SysBusDevice parent_obj;
49 
50     MemoryRegion mmio;
51     void *interrupt_vector;
52     qemu_irq parent_irq;
53     qemu_irq parent_nmi;
54     uint32_t regs[R_MAX];
55 };
56 
57 static void pic_update(struct etrax_pic *fs)
58 {
59     uint32_t vector = 0;
60     int i;
61 
62     fs->regs[R_R_MASKED_VECT] = fs->regs[R_R_VECT] & fs->regs[R_RW_MASK];
63 
64     /* The ETRAX interrupt controller signals interrupts to the core
65        through an interrupt request wire and an irq vector bus. If
66        multiple interrupts are simultaneously active it chooses vector
67        0x30 and lets the sw choose the priorities.  */
68     if (fs->regs[R_R_MASKED_VECT]) {
69         uint32_t mv = fs->regs[R_R_MASKED_VECT];
70         for (i = 0; i < 31; i++) {
71             if (mv & 1) {
72                 vector = 0x31 + i;
73                 /* Check for multiple interrupts.  */
74                 if (mv > 1)
75                     vector = 0x30;
76                 break;
77             }
78             mv >>= 1;
79         }
80     }
81 
82     if (fs->interrupt_vector) {
83         /* hack alert: ptr property */
84         *(uint32_t*)(fs->interrupt_vector) = vector;
85     }
86     qemu_set_irq(fs->parent_irq, !!vector);
87 }
88 
89 static uint64_t
90 pic_read(void *opaque, hwaddr addr, unsigned int size)
91 {
92     struct etrax_pic *fs = opaque;
93     uint32_t rval;
94 
95     rval = fs->regs[addr >> 2];
96     D(printf("%s %x=%x\n", __func__, addr, rval));
97     return rval;
98 }
99 
100 static void pic_write(void *opaque, hwaddr addr,
101                       uint64_t value, unsigned int size)
102 {
103     struct etrax_pic *fs = opaque;
104     D(printf("%s addr=%x val=%x\n", __func__, addr, value));
105 
106     if (addr == R_RW_MASK) {
107         fs->regs[R_RW_MASK] = value;
108         pic_update(fs);
109     }
110 }
111 
112 static const MemoryRegionOps pic_ops = {
113     .read = pic_read,
114     .write = pic_write,
115     .endianness = DEVICE_NATIVE_ENDIAN,
116     .valid = {
117         .min_access_size = 4,
118         .max_access_size = 4
119     }
120 };
121 
122 static void nmi_handler(void *opaque, int irq, int level)
123 {
124     struct etrax_pic *fs = (void *)opaque;
125     uint32_t mask;
126 
127     mask = 1 << irq;
128     if (level)
129         fs->regs[R_R_NMI] |= mask;
130     else
131         fs->regs[R_R_NMI] &= ~mask;
132 
133     qemu_set_irq(fs->parent_nmi, !!fs->regs[R_R_NMI]);
134 }
135 
136 static void irq_handler(void *opaque, int irq, int level)
137 {
138     struct etrax_pic *fs = (void *)opaque;
139 
140     if (irq >= 30) {
141         nmi_handler(opaque, irq, level);
142         return;
143     }
144 
145     irq -= 1;
146     fs->regs[R_R_VECT] &= ~(1 << irq);
147     fs->regs[R_R_VECT] |= (!!level << irq);
148     pic_update(fs);
149 }
150 
151 static void etraxfs_pic_init(Object *obj)
152 {
153     DeviceState *dev = DEVICE(obj);
154     struct etrax_pic *s = ETRAX_FS_PIC(obj);
155     SysBusDevice *sbd = SYS_BUS_DEVICE(obj);
156 
157     qdev_init_gpio_in(dev, irq_handler, 32);
158     sysbus_init_irq(sbd, &s->parent_irq);
159     sysbus_init_irq(sbd, &s->parent_nmi);
160 
161     memory_region_init_io(&s->mmio, obj, &pic_ops, s,
162                           "etraxfs-pic", R_MAX * 4);
163     sysbus_init_mmio(sbd, &s->mmio);
164 }
165 
166 static Property etraxfs_pic_properties[] = {
167     DEFINE_PROP_PTR("interrupt_vector", struct etrax_pic, interrupt_vector),
168     DEFINE_PROP_END_OF_LIST(),
169 };
170 
171 static void etraxfs_pic_class_init(ObjectClass *klass, void *data)
172 {
173     DeviceClass *dc = DEVICE_CLASS(klass);
174 
175     dc->props = etraxfs_pic_properties;
176     /*
177      * Note: pointer property "interrupt_vector" may remain null, thus
178      * no need for dc->user_creatable = false;
179      */
180 }
181 
182 static const TypeInfo etraxfs_pic_info = {
183     .name          = TYPE_ETRAX_FS_PIC,
184     .parent        = TYPE_SYS_BUS_DEVICE,
185     .instance_size = sizeof(struct etrax_pic),
186     .instance_init = etraxfs_pic_init,
187     .class_init    = etraxfs_pic_class_init,
188 };
189 
190 static void etraxfs_pic_register_types(void)
191 {
192     type_register_static(&etraxfs_pic_info);
193 }
194 
195 type_init(etraxfs_pic_register_types)
196