xref: /openbmc/qemu/hw/intc/xilinx_intc.c (revision 878096ee)
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     /* state of the interrupt input pins */
53     uint32_t irq_pin_state;
54 };
55 
56 static void update_irq(struct xlx_pic *p)
57 {
58     uint32_t i;
59 
60     /* level triggered interrupt */
61     if (p->regs[R_MER] & 2) {
62         p->regs[R_ISR] |= p->irq_pin_state & ~p->c_kind_of_intr;
63     }
64 
65     /* Update the pending register.  */
66     p->regs[R_IPR] = p->regs[R_ISR] & p->regs[R_IER];
67 
68     /* Update the vector register.  */
69     for (i = 0; i < 32; i++) {
70         if (p->regs[R_IPR] & (1 << i))
71             break;
72     }
73     if (i == 32)
74         i = ~0;
75 
76     p->regs[R_IVR] = i;
77     qemu_set_irq(p->parent_irq, (p->regs[R_MER] & 1) && p->regs[R_IPR]);
78 }
79 
80 static uint64_t
81 pic_read(void *opaque, hwaddr addr, unsigned int size)
82 {
83     struct xlx_pic *p = opaque;
84     uint32_t r = 0;
85 
86     addr >>= 2;
87     switch (addr)
88     {
89         default:
90             if (addr < ARRAY_SIZE(p->regs))
91                 r = p->regs[addr];
92             break;
93 
94     }
95     D(printf("%s %x=%x\n", __func__, addr * 4, r));
96     return r;
97 }
98 
99 static void
100 pic_write(void *opaque, hwaddr addr,
101           uint64_t val64, unsigned int size)
102 {
103     struct xlx_pic *p = opaque;
104     uint32_t value = val64;
105 
106     addr >>= 2;
107     D(qemu_log("%s addr=%x val=%x\n", __func__, addr * 4, value));
108     switch (addr)
109     {
110         case R_IAR:
111             p->regs[R_ISR] &= ~value; /* ACK.  */
112             break;
113         case R_SIE:
114             p->regs[R_IER] |= value;  /* Atomic set ie.  */
115             break;
116         case R_CIE:
117             p->regs[R_IER] &= ~value; /* Atomic clear ie.  */
118             break;
119         case R_ISR:
120             if ((p->regs[R_MER] & 2)) {
121                 break;
122             }
123             /* fallthrough */
124         default:
125             if (addr < ARRAY_SIZE(p->regs))
126                 p->regs[addr] = value;
127             break;
128     }
129     update_irq(p);
130 }
131 
132 static const MemoryRegionOps pic_ops = {
133     .read = pic_read,
134     .write = pic_write,
135     .endianness = DEVICE_NATIVE_ENDIAN,
136     .valid = {
137         .min_access_size = 4,
138         .max_access_size = 4
139     }
140 };
141 
142 static void irq_handler(void *opaque, int irq, int level)
143 {
144     struct xlx_pic *p = opaque;
145 
146     /* edge triggered interrupt */
147     if (p->c_kind_of_intr & (1 << irq) && p->regs[R_MER] & 2) {
148         p->regs[R_ISR] |= (level << irq);
149     }
150 
151     p->irq_pin_state &= ~(1 << irq);
152     p->irq_pin_state |= level << irq;
153     update_irq(p);
154 }
155 
156 static int xilinx_intc_init(SysBusDevice *dev)
157 {
158     struct xlx_pic *p = FROM_SYSBUS(typeof (*p), dev);
159 
160     qdev_init_gpio_in(&dev->qdev, irq_handler, 32);
161     sysbus_init_irq(dev, &p->parent_irq);
162 
163     memory_region_init_io(&p->mmio, &pic_ops, p, "xlnx.xps-intc", R_MAX * 4);
164     sysbus_init_mmio(dev, &p->mmio);
165     return 0;
166 }
167 
168 static Property xilinx_intc_properties[] = {
169     DEFINE_PROP_UINT32("kind-of-intr", struct xlx_pic, c_kind_of_intr, 0),
170     DEFINE_PROP_END_OF_LIST(),
171 };
172 
173 static void xilinx_intc_class_init(ObjectClass *klass, void *data)
174 {
175     DeviceClass *dc = DEVICE_CLASS(klass);
176     SysBusDeviceClass *k = SYS_BUS_DEVICE_CLASS(klass);
177 
178     k->init = xilinx_intc_init;
179     dc->props = xilinx_intc_properties;
180 }
181 
182 static const TypeInfo xilinx_intc_info = {
183     .name          = "xlnx.xps-intc",
184     .parent        = TYPE_SYS_BUS_DEVICE,
185     .instance_size = sizeof(struct xlx_pic),
186     .class_init    = xilinx_intc_class_init,
187 };
188 
189 static void xilinx_intc_register_types(void)
190 {
191     type_register_static(&xilinx_intc_info);
192 }
193 
194 type_init(xilinx_intc_register_types)
195