xref: /openbmc/qemu/hw/intc/xilinx_intc.c (revision c00506aa)
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 #include "qom/object.h"
31 
32 #define D(x)
33 
34 #define R_ISR       0
35 #define R_IPR       1
36 #define R_IER       2
37 #define R_IAR       3
38 #define R_SIE       4
39 #define R_CIE       5
40 #define R_IVR       6
41 #define R_MER       7
42 #define R_MAX       8
43 
44 #define TYPE_XILINX_INTC "xlnx.xps-intc"
45 DECLARE_INSTANCE_CHECKER(struct xlx_pic, XILINX_INTC,
46                          TYPE_XILINX_INTC)
47 
48 struct xlx_pic
49 {
50     SysBusDevice parent_obj;
51 
52     MemoryRegion mmio;
53     qemu_irq parent_irq;
54 
55     /* Configuration reg chosen at synthesis-time. QEMU populates
56        the bits at board-setup.  */
57     uint32_t c_kind_of_intr;
58 
59     /* Runtime control registers.  */
60     uint32_t regs[R_MAX];
61     /* state of the interrupt input pins */
62     uint32_t irq_pin_state;
63 };
64 
65 static void update_irq(struct xlx_pic *p)
66 {
67     uint32_t i;
68 
69     /* level triggered interrupt */
70     if (p->regs[R_MER] & 2) {
71         p->regs[R_ISR] |= p->irq_pin_state & ~p->c_kind_of_intr;
72     }
73 
74     /* Update the pending register.  */
75     p->regs[R_IPR] = p->regs[R_ISR] & p->regs[R_IER];
76 
77     /* Update the vector register.  */
78     for (i = 0; i < 32; i++) {
79         if (p->regs[R_IPR] & (1U << i)) {
80             break;
81         }
82     }
83     if (i == 32)
84         i = ~0;
85 
86     p->regs[R_IVR] = i;
87     qemu_set_irq(p->parent_irq, (p->regs[R_MER] & 1) && p->regs[R_IPR]);
88 }
89 
90 static uint64_t
91 pic_read(void *opaque, hwaddr addr, unsigned int size)
92 {
93     struct xlx_pic *p = opaque;
94     uint32_t r = 0;
95 
96     addr >>= 2;
97     switch (addr)
98     {
99         default:
100             if (addr < ARRAY_SIZE(p->regs))
101                 r = p->regs[addr];
102             break;
103 
104     }
105     D(printf("%s %x=%x\n", __func__, addr * 4, r));
106     return r;
107 }
108 
109 static void
110 pic_write(void *opaque, hwaddr addr,
111           uint64_t val64, unsigned int size)
112 {
113     struct xlx_pic *p = opaque;
114     uint32_t value = val64;
115 
116     addr >>= 2;
117     D(qemu_log("%s addr=%x val=%x\n", __func__, addr * 4, value));
118     switch (addr)
119     {
120         case R_IAR:
121             p->regs[R_ISR] &= ~value; /* ACK.  */
122             break;
123         case R_SIE:
124             p->regs[R_IER] |= value;  /* Atomic set ie.  */
125             break;
126         case R_CIE:
127             p->regs[R_IER] &= ~value; /* Atomic clear ie.  */
128             break;
129         case R_MER:
130             p->regs[R_MER] = value & 0x3;
131             break;
132         case R_ISR:
133             if ((p->regs[R_MER] & 2)) {
134                 break;
135             }
136             /* fallthrough */
137         default:
138             if (addr < ARRAY_SIZE(p->regs))
139                 p->regs[addr] = value;
140             break;
141     }
142     update_irq(p);
143 }
144 
145 static const MemoryRegionOps pic_ops = {
146     .read = pic_read,
147     .write = pic_write,
148     .endianness = DEVICE_NATIVE_ENDIAN,
149     .valid = {
150         .min_access_size = 4,
151         .max_access_size = 4
152     }
153 };
154 
155 static void irq_handler(void *opaque, int irq, int level)
156 {
157     struct xlx_pic *p = opaque;
158 
159     /* edge triggered interrupt */
160     if (p->c_kind_of_intr & (1 << irq) && p->regs[R_MER] & 2) {
161         p->regs[R_ISR] |= (level << irq);
162     }
163 
164     p->irq_pin_state &= ~(1 << irq);
165     p->irq_pin_state |= level << irq;
166     update_irq(p);
167 }
168 
169 static void xilinx_intc_init(Object *obj)
170 {
171     struct xlx_pic *p = XILINX_INTC(obj);
172 
173     qdev_init_gpio_in(DEVICE(obj), irq_handler, 32);
174     sysbus_init_irq(SYS_BUS_DEVICE(obj), &p->parent_irq);
175 
176     memory_region_init_io(&p->mmio, obj, &pic_ops, p, "xlnx.xps-intc",
177                           R_MAX * 4);
178     sysbus_init_mmio(SYS_BUS_DEVICE(obj), &p->mmio);
179 }
180 
181 static Property xilinx_intc_properties[] = {
182     DEFINE_PROP_UINT32("kind-of-intr", struct xlx_pic, c_kind_of_intr, 0),
183     DEFINE_PROP_END_OF_LIST(),
184 };
185 
186 static void xilinx_intc_class_init(ObjectClass *klass, void *data)
187 {
188     DeviceClass *dc = DEVICE_CLASS(klass);
189 
190     device_class_set_props(dc, xilinx_intc_properties);
191 }
192 
193 static const TypeInfo xilinx_intc_info = {
194     .name          = TYPE_XILINX_INTC,
195     .parent        = TYPE_SYS_BUS_DEVICE,
196     .instance_size = sizeof(struct xlx_pic),
197     .instance_init = xilinx_intc_init,
198     .class_init    = xilinx_intc_class_init,
199 };
200 
201 static void xilinx_intc_register_types(void)
202 {
203     type_register_static(&xilinx_intc_info);
204 }
205 
206 type_init(xilinx_intc_register_types)
207