xref: /openbmc/qemu/hw/intc/xilinx_intc.c (revision 49ab747f)
1 /*
2  * QEMU Xilinx OPB Interrupt Controller.
3  *
4  * Copyright (c) 2009 Edgar E. Iglesias.
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 
28 #define D(x)
29 
30 #define R_ISR       0
31 #define R_IPR       1
32 #define R_IER       2
33 #define R_IAR       3
34 #define R_SIE       4
35 #define R_CIE       5
36 #define R_IVR       6
37 #define R_MER       7
38 #define R_MAX       8
39 
40 struct xlx_pic
41 {
42     SysBusDevice busdev;
43     MemoryRegion mmio;
44     qemu_irq parent_irq;
45 
46     /* Configuration reg chosen at synthesis-time. QEMU populates
47        the bits at board-setup.  */
48     uint32_t c_kind_of_intr;
49 
50     /* Runtime control registers.  */
51     uint32_t regs[R_MAX];
52 };
53 
54 static void update_irq(struct xlx_pic *p)
55 {
56     uint32_t i;
57     /* Update the pending register.  */
58     p->regs[R_IPR] = p->regs[R_ISR] & p->regs[R_IER];
59 
60     /* Update the vector register.  */
61     for (i = 0; i < 32; i++) {
62         if (p->regs[R_IPR] & (1 << i))
63             break;
64     }
65     if (i == 32)
66         i = ~0;
67 
68     p->regs[R_IVR] = i;
69     if ((p->regs[R_MER] & 1) && p->regs[R_IPR]) {
70         qemu_irq_raise(p->parent_irq);
71     } else {
72         qemu_irq_lower(p->parent_irq);
73     }
74 }
75 
76 static uint64_t
77 pic_read(void *opaque, hwaddr addr, unsigned int size)
78 {
79     struct xlx_pic *p = opaque;
80     uint32_t r = 0;
81 
82     addr >>= 2;
83     switch (addr)
84     {
85         default:
86             if (addr < ARRAY_SIZE(p->regs))
87                 r = p->regs[addr];
88             break;
89 
90     }
91     D(printf("%s %x=%x\n", __func__, addr * 4, r));
92     return r;
93 }
94 
95 static void
96 pic_write(void *opaque, hwaddr addr,
97           uint64_t val64, unsigned int size)
98 {
99     struct xlx_pic *p = opaque;
100     uint32_t value = val64;
101 
102     addr >>= 2;
103     D(qemu_log("%s addr=%x val=%x\n", __func__, addr * 4, value));
104     switch (addr)
105     {
106         case R_IAR:
107             p->regs[R_ISR] &= ~value; /* ACK.  */
108             break;
109         case R_SIE:
110             p->regs[R_IER] |= value;  /* Atomic set ie.  */
111             break;
112         case R_CIE:
113             p->regs[R_IER] &= ~value; /* Atomic clear ie.  */
114             break;
115         default:
116             if (addr < ARRAY_SIZE(p->regs))
117                 p->regs[addr] = value;
118             break;
119     }
120     update_irq(p);
121 }
122 
123 static const MemoryRegionOps pic_ops = {
124     .read = pic_read,
125     .write = pic_write,
126     .endianness = DEVICE_NATIVE_ENDIAN,
127     .valid = {
128         .min_access_size = 4,
129         .max_access_size = 4
130     }
131 };
132 
133 static void irq_handler(void *opaque, int irq, int level)
134 {
135     struct xlx_pic *p = opaque;
136 
137     if (!(p->regs[R_MER] & 2)) {
138         qemu_irq_lower(p->parent_irq);
139         return;
140     }
141 
142     /* Update source flops. Don't clear unless level triggered.
143        Edge triggered interrupts only go away when explicitely acked to
144        the interrupt controller.  */
145     if (!(p->c_kind_of_intr & (1 << irq)) || level) {
146         p->regs[R_ISR] &= ~(1 << irq);
147         p->regs[R_ISR] |= (level << irq);
148     }
149     update_irq(p);
150 }
151 
152 static int xilinx_intc_init(SysBusDevice *dev)
153 {
154     struct xlx_pic *p = FROM_SYSBUS(typeof (*p), dev);
155 
156     qdev_init_gpio_in(&dev->qdev, irq_handler, 32);
157     sysbus_init_irq(dev, &p->parent_irq);
158 
159     memory_region_init_io(&p->mmio, &pic_ops, p, "xlnx.xps-intc", R_MAX * 4);
160     sysbus_init_mmio(dev, &p->mmio);
161     return 0;
162 }
163 
164 static Property xilinx_intc_properties[] = {
165     DEFINE_PROP_UINT32("kind-of-intr", struct xlx_pic, c_kind_of_intr, 0),
166     DEFINE_PROP_END_OF_LIST(),
167 };
168 
169 static void xilinx_intc_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 = xilinx_intc_init;
175     dc->props = xilinx_intc_properties;
176 }
177 
178 static const TypeInfo xilinx_intc_info = {
179     .name          = "xlnx.xps-intc",
180     .parent        = TYPE_SYS_BUS_DEVICE,
181     .instance_size = sizeof(struct xlx_pic),
182     .class_init    = xilinx_intc_class_init,
183 };
184 
185 static void xilinx_intc_register_types(void)
186 {
187     type_register_static(&xilinx_intc_info);
188 }
189 
190 type_init(xilinx_intc_register_types)
191