xref: /openbmc/qemu/hw/intc/xilinx_intc.c (revision 135b03cb)
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 "qemu/osdep.h"
26 #include "hw/sysbus.h"
27 #include "qemu/module.h"
28 #include "hw/irq.h"
29 #include "hw/qdev-properties.h"
30 
31 #define D(x)
32 
33 #define R_ISR       0
34 #define R_IPR       1
35 #define R_IER       2
36 #define R_IAR       3
37 #define R_SIE       4
38 #define R_CIE       5
39 #define R_IVR       6
40 #define R_MER       7
41 #define R_MAX       8
42 
43 #define TYPE_XILINX_INTC "xlnx.xps-intc"
44 #define XILINX_INTC(obj) OBJECT_CHECK(struct xlx_pic, (obj), TYPE_XILINX_INTC)
45 
46 struct xlx_pic
47 {
48     SysBusDevice parent_obj;
49 
50     MemoryRegion mmio;
51     qemu_irq parent_irq;
52 
53     /* Configuration reg chosen at synthesis-time. QEMU populates
54        the bits at board-setup.  */
55     uint32_t c_kind_of_intr;
56 
57     /* Runtime control registers.  */
58     uint32_t regs[R_MAX];
59     /* state of the interrupt input pins */
60     uint32_t irq_pin_state;
61 };
62 
63 static void update_irq(struct xlx_pic *p)
64 {
65     uint32_t i;
66 
67     /* level triggered interrupt */
68     if (p->regs[R_MER] & 2) {
69         p->regs[R_ISR] |= p->irq_pin_state & ~p->c_kind_of_intr;
70     }
71 
72     /* Update the pending register.  */
73     p->regs[R_IPR] = p->regs[R_ISR] & p->regs[R_IER];
74 
75     /* Update the vector register.  */
76     for (i = 0; i < 32; i++) {
77         if (p->regs[R_IPR] & (1U << i)) {
78             break;
79         }
80     }
81     if (i == 32)
82         i = ~0;
83 
84     p->regs[R_IVR] = i;
85     qemu_set_irq(p->parent_irq, (p->regs[R_MER] & 1) && p->regs[R_IPR]);
86 }
87 
88 static uint64_t
89 pic_read(void *opaque, hwaddr addr, unsigned int size)
90 {
91     struct xlx_pic *p = opaque;
92     uint32_t r = 0;
93 
94     addr >>= 2;
95     switch (addr)
96     {
97         default:
98             if (addr < ARRAY_SIZE(p->regs))
99                 r = p->regs[addr];
100             break;
101 
102     }
103     D(printf("%s %x=%x\n", __func__, addr * 4, r));
104     return r;
105 }
106 
107 static void
108 pic_write(void *opaque, hwaddr addr,
109           uint64_t val64, unsigned int size)
110 {
111     struct xlx_pic *p = opaque;
112     uint32_t value = val64;
113 
114     addr >>= 2;
115     D(qemu_log("%s addr=%x val=%x\n", __func__, addr * 4, value));
116     switch (addr)
117     {
118         case R_IAR:
119             p->regs[R_ISR] &= ~value; /* ACK.  */
120             break;
121         case R_SIE:
122             p->regs[R_IER] |= value;  /* Atomic set ie.  */
123             break;
124         case R_CIE:
125             p->regs[R_IER] &= ~value; /* Atomic clear ie.  */
126             break;
127         case R_MER:
128             p->regs[R_MER] = value & 0x3;
129             break;
130         case R_ISR:
131             if ((p->regs[R_MER] & 2)) {
132                 break;
133             }
134             /* fallthrough */
135         default:
136             if (addr < ARRAY_SIZE(p->regs))
137                 p->regs[addr] = value;
138             break;
139     }
140     update_irq(p);
141 }
142 
143 static const MemoryRegionOps pic_ops = {
144     .read = pic_read,
145     .write = pic_write,
146     .endianness = DEVICE_NATIVE_ENDIAN,
147     .valid = {
148         .min_access_size = 4,
149         .max_access_size = 4
150     }
151 };
152 
153 static void irq_handler(void *opaque, int irq, int level)
154 {
155     struct xlx_pic *p = opaque;
156 
157     /* edge triggered interrupt */
158     if (p->c_kind_of_intr & (1 << irq) && p->regs[R_MER] & 2) {
159         p->regs[R_ISR] |= (level << irq);
160     }
161 
162     p->irq_pin_state &= ~(1 << irq);
163     p->irq_pin_state |= level << irq;
164     update_irq(p);
165 }
166 
167 static void xilinx_intc_init(Object *obj)
168 {
169     struct xlx_pic *p = XILINX_INTC(obj);
170 
171     qdev_init_gpio_in(DEVICE(obj), irq_handler, 32);
172     sysbus_init_irq(SYS_BUS_DEVICE(obj), &p->parent_irq);
173 
174     memory_region_init_io(&p->mmio, obj, &pic_ops, p, "xlnx.xps-intc",
175                           R_MAX * 4);
176     sysbus_init_mmio(SYS_BUS_DEVICE(obj), &p->mmio);
177 }
178 
179 static Property xilinx_intc_properties[] = {
180     DEFINE_PROP_UINT32("kind-of-intr", struct xlx_pic, c_kind_of_intr, 0),
181     DEFINE_PROP_END_OF_LIST(),
182 };
183 
184 static void xilinx_intc_class_init(ObjectClass *klass, void *data)
185 {
186     DeviceClass *dc = DEVICE_CLASS(klass);
187 
188     dc->props = xilinx_intc_properties;
189 }
190 
191 static const TypeInfo xilinx_intc_info = {
192     .name          = TYPE_XILINX_INTC,
193     .parent        = TYPE_SYS_BUS_DEVICE,
194     .instance_size = sizeof(struct xlx_pic),
195     .instance_init = xilinx_intc_init,
196     .class_init    = xilinx_intc_class_init,
197 };
198 
199 static void xilinx_intc_register_types(void)
200 {
201     type_register_static(&xilinx_intc_info);
202 }
203 
204 type_init(xilinx_intc_register_types)
205