xref: /openbmc/qemu/hw/intc/etraxfs_pic.c (revision 2e142114)
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 #define TYPE_ETRAX_FS_PIC "etraxfs,pic"
40 #define ETRAX_FS_PIC(obj) \
41     OBJECT_CHECK(struct etrax_pic, (obj), TYPE_ETRAX_FS_PIC)
42 
43 struct etrax_pic
44 {
45     SysBusDevice parent_obj;
46 
47     MemoryRegion mmio;
48     void *interrupt_vector;
49     qemu_irq parent_irq;
50     qemu_irq parent_nmi;
51     uint32_t regs[R_MAX];
52 };
53 
54 static void pic_update(struct etrax_pic *fs)
55 {
56     uint32_t vector = 0;
57     int i;
58 
59     fs->regs[R_R_MASKED_VECT] = fs->regs[R_R_VECT] & fs->regs[R_RW_MASK];
60 
61     /* The ETRAX interrupt controller signals interrupts to the core
62        through an interrupt request wire and an irq vector bus. If
63        multiple interrupts are simultaneously active it chooses vector
64        0x30 and lets the sw choose the priorities.  */
65     if (fs->regs[R_R_MASKED_VECT]) {
66         uint32_t mv = fs->regs[R_R_MASKED_VECT];
67         for (i = 0; i < 31; i++) {
68             if (mv & 1) {
69                 vector = 0x31 + i;
70                 /* Check for multiple interrupts.  */
71                 if (mv > 1)
72                     vector = 0x30;
73                 break;
74             }
75             mv >>= 1;
76         }
77     }
78 
79     if (fs->interrupt_vector) {
80         /* hack alert: ptr property */
81         *(uint32_t*)(fs->interrupt_vector) = vector;
82     }
83     qemu_set_irq(fs->parent_irq, !!vector);
84 }
85 
86 static uint64_t
87 pic_read(void *opaque, hwaddr addr, unsigned int size)
88 {
89     struct etrax_pic *fs = opaque;
90     uint32_t rval;
91 
92     rval = fs->regs[addr >> 2];
93     D(printf("%s %x=%x\n", __func__, addr, rval));
94     return rval;
95 }
96 
97 static void pic_write(void *opaque, hwaddr addr,
98                       uint64_t value, unsigned int size)
99 {
100     struct etrax_pic *fs = opaque;
101     D(printf("%s addr=%x val=%x\n", __func__, addr, value));
102 
103     if (addr == R_RW_MASK) {
104         fs->regs[R_RW_MASK] = value;
105         pic_update(fs);
106     }
107 }
108 
109 static const MemoryRegionOps pic_ops = {
110     .read = pic_read,
111     .write = pic_write,
112     .endianness = DEVICE_NATIVE_ENDIAN,
113     .valid = {
114         .min_access_size = 4,
115         .max_access_size = 4
116     }
117 };
118 
119 static void nmi_handler(void *opaque, int irq, int level)
120 {
121     struct etrax_pic *fs = (void *)opaque;
122     uint32_t mask;
123 
124     mask = 1 << irq;
125     if (level)
126         fs->regs[R_R_NMI] |= mask;
127     else
128         fs->regs[R_R_NMI] &= ~mask;
129 
130     qemu_set_irq(fs->parent_nmi, !!fs->regs[R_R_NMI]);
131 }
132 
133 static void irq_handler(void *opaque, int irq, int level)
134 {
135     struct etrax_pic *fs = (void *)opaque;
136 
137     if (irq >= 30)
138         return nmi_handler(opaque, irq, level);
139 
140     irq -= 1;
141     fs->regs[R_R_VECT] &= ~(1 << irq);
142     fs->regs[R_R_VECT] |= (!!level << irq);
143     pic_update(fs);
144 }
145 
146 static int etraxfs_pic_init(SysBusDevice *sbd)
147 {
148     DeviceState *dev = DEVICE(sbd);
149     struct etrax_pic *s = ETRAX_FS_PIC(dev);
150 
151     qdev_init_gpio_in(dev, irq_handler, 32);
152     sysbus_init_irq(sbd, &s->parent_irq);
153     sysbus_init_irq(sbd, &s->parent_nmi);
154 
155     memory_region_init_io(&s->mmio, OBJECT(s), &pic_ops, s,
156                           "etraxfs-pic", R_MAX * 4);
157     sysbus_init_mmio(sbd, &s->mmio);
158     return 0;
159 }
160 
161 static Property etraxfs_pic_properties[] = {
162     DEFINE_PROP_PTR("interrupt_vector", struct etrax_pic, interrupt_vector),
163     DEFINE_PROP_END_OF_LIST(),
164 };
165 
166 static void etraxfs_pic_class_init(ObjectClass *klass, void *data)
167 {
168     DeviceClass *dc = DEVICE_CLASS(klass);
169     SysBusDeviceClass *k = SYS_BUS_DEVICE_CLASS(klass);
170 
171     k->init = etraxfs_pic_init;
172     dc->props = etraxfs_pic_properties;
173 }
174 
175 static const TypeInfo etraxfs_pic_info = {
176     .name          = TYPE_ETRAX_FS_PIC,
177     .parent        = TYPE_SYS_BUS_DEVICE,
178     .instance_size = sizeof(struct etrax_pic),
179     .class_init    = etraxfs_pic_class_init,
180 };
181 
182 static void etraxfs_pic_register_types(void)
183 {
184     type_register_static(&etraxfs_pic_info);
185 }
186 
187 type_init(etraxfs_pic_register_types)
188