xref: /openbmc/qemu/hw/intc/xilinx_intc.c (revision 7f4f0a22)
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     qemu_set_irq(p->parent_irq, (p->regs[R_MER] & 1) && p->regs[R_IPR]);
70 }
71 
72 static uint64_t
73 pic_read(void *opaque, hwaddr addr, unsigned int size)
74 {
75     struct xlx_pic *p = opaque;
76     uint32_t r = 0;
77 
78     addr >>= 2;
79     switch (addr)
80     {
81         default:
82             if (addr < ARRAY_SIZE(p->regs))
83                 r = p->regs[addr];
84             break;
85 
86     }
87     D(printf("%s %x=%x\n", __func__, addr * 4, r));
88     return r;
89 }
90 
91 static void
92 pic_write(void *opaque, hwaddr addr,
93           uint64_t val64, unsigned int size)
94 {
95     struct xlx_pic *p = opaque;
96     uint32_t value = val64;
97 
98     addr >>= 2;
99     D(qemu_log("%s addr=%x val=%x\n", __func__, addr * 4, value));
100     switch (addr)
101     {
102         case R_IAR:
103             p->regs[R_ISR] &= ~value; /* ACK.  */
104             break;
105         case R_SIE:
106             p->regs[R_IER] |= value;  /* Atomic set ie.  */
107             break;
108         case R_CIE:
109             p->regs[R_IER] &= ~value; /* Atomic clear ie.  */
110             break;
111         default:
112             if (addr < ARRAY_SIZE(p->regs))
113                 p->regs[addr] = value;
114             break;
115     }
116     update_irq(p);
117 }
118 
119 static const MemoryRegionOps pic_ops = {
120     .read = pic_read,
121     .write = pic_write,
122     .endianness = DEVICE_NATIVE_ENDIAN,
123     .valid = {
124         .min_access_size = 4,
125         .max_access_size = 4
126     }
127 };
128 
129 static void irq_handler(void *opaque, int irq, int level)
130 {
131     struct xlx_pic *p = opaque;
132 
133     if (!(p->regs[R_MER] & 2)) {
134         qemu_irq_lower(p->parent_irq);
135         return;
136     }
137 
138     /* Update source flops. Don't clear unless level triggered.
139        Edge triggered interrupts only go away when explicitely acked to
140        the interrupt controller.  */
141     if (!(p->c_kind_of_intr & (1 << irq)) || level) {
142         p->regs[R_ISR] &= ~(1 << irq);
143         p->regs[R_ISR] |= (level << irq);
144     }
145     update_irq(p);
146 }
147 
148 static int xilinx_intc_init(SysBusDevice *dev)
149 {
150     struct xlx_pic *p = FROM_SYSBUS(typeof (*p), dev);
151 
152     qdev_init_gpio_in(&dev->qdev, irq_handler, 32);
153     sysbus_init_irq(dev, &p->parent_irq);
154 
155     memory_region_init_io(&p->mmio, &pic_ops, p, "xlnx.xps-intc", R_MAX * 4);
156     sysbus_init_mmio(dev, &p->mmio);
157     return 0;
158 }
159 
160 static Property xilinx_intc_properties[] = {
161     DEFINE_PROP_UINT32("kind-of-intr", struct xlx_pic, c_kind_of_intr, 0),
162     DEFINE_PROP_END_OF_LIST(),
163 };
164 
165 static void xilinx_intc_class_init(ObjectClass *klass, void *data)
166 {
167     DeviceClass *dc = DEVICE_CLASS(klass);
168     SysBusDeviceClass *k = SYS_BUS_DEVICE_CLASS(klass);
169 
170     k->init = xilinx_intc_init;
171     dc->props = xilinx_intc_properties;
172 }
173 
174 static const TypeInfo xilinx_intc_info = {
175     .name          = "xlnx.xps-intc",
176     .parent        = TYPE_SYS_BUS_DEVICE,
177     .instance_size = sizeof(struct xlx_pic),
178     .class_init    = xilinx_intc_class_init,
179 };
180 
181 static void xilinx_intc_register_types(void)
182 {
183     type_register_static(&xilinx_intc_info);
184 }
185 
186 type_init(xilinx_intc_register_types)
187