xref: /openbmc/qemu/hw/intc/etraxfs_pic.c (revision 9884abee)
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 "hw/hw.h"
28 //#include "pc.h"
29 //#include "etraxfs.h"
30 
31 #define D(x)
32 
33 #define R_RW_MASK   0
34 #define R_R_VECT    1
35 #define R_R_MASKED_VECT 2
36 #define R_R_NMI     3
37 #define R_R_GURU    4
38 #define R_MAX       5
39 
40 #define TYPE_ETRAX_FS_PIC "etraxfs,pic"
41 #define ETRAX_FS_PIC(obj) \
42     OBJECT_CHECK(struct etrax_pic, (obj), TYPE_ETRAX_FS_PIC)
43 
44 struct etrax_pic
45 {
46     SysBusDevice parent_obj;
47 
48     MemoryRegion mmio;
49     void *interrupt_vector;
50     qemu_irq parent_irq;
51     qemu_irq parent_nmi;
52     uint32_t regs[R_MAX];
53 };
54 
55 static void pic_update(struct etrax_pic *fs)
56 {
57     uint32_t vector = 0;
58     int i;
59 
60     fs->regs[R_R_MASKED_VECT] = fs->regs[R_R_VECT] & fs->regs[R_RW_MASK];
61 
62     /* The ETRAX interrupt controller signals interrupts to the core
63        through an interrupt request wire and an irq vector bus. If
64        multiple interrupts are simultaneously active it chooses vector
65        0x30 and lets the sw choose the priorities.  */
66     if (fs->regs[R_R_MASKED_VECT]) {
67         uint32_t mv = fs->regs[R_R_MASKED_VECT];
68         for (i = 0; i < 31; i++) {
69             if (mv & 1) {
70                 vector = 0x31 + i;
71                 /* Check for multiple interrupts.  */
72                 if (mv > 1)
73                     vector = 0x30;
74                 break;
75             }
76             mv >>= 1;
77         }
78     }
79 
80     if (fs->interrupt_vector) {
81         /* hack alert: ptr property */
82         *(uint32_t*)(fs->interrupt_vector) = vector;
83     }
84     qemu_set_irq(fs->parent_irq, !!vector);
85 }
86 
87 static uint64_t
88 pic_read(void *opaque, hwaddr addr, unsigned int size)
89 {
90     struct etrax_pic *fs = opaque;
91     uint32_t rval;
92 
93     rval = fs->regs[addr >> 2];
94     D(printf("%s %x=%x\n", __func__, addr, rval));
95     return rval;
96 }
97 
98 static void pic_write(void *opaque, hwaddr addr,
99                       uint64_t value, unsigned int size)
100 {
101     struct etrax_pic *fs = opaque;
102     D(printf("%s addr=%x val=%x\n", __func__, addr, value));
103 
104     if (addr == R_RW_MASK) {
105         fs->regs[R_RW_MASK] = value;
106         pic_update(fs);
107     }
108 }
109 
110 static const MemoryRegionOps pic_ops = {
111     .read = pic_read,
112     .write = pic_write,
113     .endianness = DEVICE_NATIVE_ENDIAN,
114     .valid = {
115         .min_access_size = 4,
116         .max_access_size = 4
117     }
118 };
119 
120 static void nmi_handler(void *opaque, int irq, int level)
121 {
122     struct etrax_pic *fs = (void *)opaque;
123     uint32_t mask;
124 
125     mask = 1 << irq;
126     if (level)
127         fs->regs[R_R_NMI] |= mask;
128     else
129         fs->regs[R_R_NMI] &= ~mask;
130 
131     qemu_set_irq(fs->parent_nmi, !!fs->regs[R_R_NMI]);
132 }
133 
134 static void irq_handler(void *opaque, int irq, int level)
135 {
136     struct etrax_pic *fs = (void *)opaque;
137 
138     if (irq >= 30) {
139         nmi_handler(opaque, irq, level);
140         return;
141     }
142 
143     irq -= 1;
144     fs->regs[R_R_VECT] &= ~(1 << irq);
145     fs->regs[R_R_VECT] |= (!!level << irq);
146     pic_update(fs);
147 }
148 
149 static int etraxfs_pic_init(SysBusDevice *sbd)
150 {
151     DeviceState *dev = DEVICE(sbd);
152     struct etrax_pic *s = ETRAX_FS_PIC(dev);
153 
154     qdev_init_gpio_in(dev, irq_handler, 32);
155     sysbus_init_irq(sbd, &s->parent_irq);
156     sysbus_init_irq(sbd, &s->parent_nmi);
157 
158     memory_region_init_io(&s->mmio, OBJECT(s), &pic_ops, s,
159                           "etraxfs-pic", R_MAX * 4);
160     sysbus_init_mmio(sbd, &s->mmio);
161     return 0;
162 }
163 
164 static Property etraxfs_pic_properties[] = {
165     DEFINE_PROP_PTR("interrupt_vector", struct etrax_pic, interrupt_vector),
166     DEFINE_PROP_END_OF_LIST(),
167 };
168 
169 static void etraxfs_pic_class_init(ObjectClass *klass, void *data)
170 {
171     DeviceClass *dc = DEVICE_CLASS(klass);
172     SysBusDeviceClass *k = SYS_BUS_DEVICE_CLASS(klass);
173 
174     k->init = etraxfs_pic_init;
175     dc->props = etraxfs_pic_properties;
176     /*
177      * Note: pointer property "interrupt_vector" may remain null, thus
178      * no need for dc->cannot_instantiate_with_device_add_yet = true;
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     .class_init    = etraxfs_pic_class_init,
187 };
188 
189 static void etraxfs_pic_register_types(void)
190 {
191     type_register_static(&etraxfs_pic_info);
192 }
193 
194 type_init(etraxfs_pic_register_types)
195