xref: /openbmc/qemu/hw/intc/xilinx_intc.c (revision 09a274d8)
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 "hw/hw.h"
28 
29 #define D(x)
30 
31 #define R_ISR       0
32 #define R_IPR       1
33 #define R_IER       2
34 #define R_IAR       3
35 #define R_SIE       4
36 #define R_CIE       5
37 #define R_IVR       6
38 #define R_MER       7
39 #define R_MAX       8
40 
41 #define TYPE_XILINX_INTC "xlnx.xps-intc"
42 #define XILINX_INTC(obj) OBJECT_CHECK(struct xlx_pic, (obj), TYPE_XILINX_INTC)
43 
44 struct xlx_pic
45 {
46     SysBusDevice parent_obj;
47 
48     MemoryRegion mmio;
49     qemu_irq parent_irq;
50 
51     /* Configuration reg chosen at synthesis-time. QEMU populates
52        the bits at board-setup.  */
53     uint32_t c_kind_of_intr;
54 
55     /* Runtime control registers.  */
56     uint32_t regs[R_MAX];
57     /* state of the interrupt input pins */
58     uint32_t irq_pin_state;
59 };
60 
61 static void update_irq(struct xlx_pic *p)
62 {
63     uint32_t i;
64 
65     /* level triggered interrupt */
66     if (p->regs[R_MER] & 2) {
67         p->regs[R_ISR] |= p->irq_pin_state & ~p->c_kind_of_intr;
68     }
69 
70     /* Update the pending register.  */
71     p->regs[R_IPR] = p->regs[R_ISR] & p->regs[R_IER];
72 
73     /* Update the vector register.  */
74     for (i = 0; i < 32; i++) {
75         if (p->regs[R_IPR] & (1U << i)) {
76             break;
77         }
78     }
79     if (i == 32)
80         i = ~0;
81 
82     p->regs[R_IVR] = i;
83     qemu_set_irq(p->parent_irq, (p->regs[R_MER] & 1) && p->regs[R_IPR]);
84 }
85 
86 static uint64_t
87 pic_read(void *opaque, hwaddr addr, unsigned int size)
88 {
89     struct xlx_pic *p = opaque;
90     uint32_t r = 0;
91 
92     addr >>= 2;
93     switch (addr)
94     {
95         default:
96             if (addr < ARRAY_SIZE(p->regs))
97                 r = p->regs[addr];
98             break;
99 
100     }
101     D(printf("%s %x=%x\n", __func__, addr * 4, r));
102     return r;
103 }
104 
105 static void
106 pic_write(void *opaque, hwaddr addr,
107           uint64_t val64, unsigned int size)
108 {
109     struct xlx_pic *p = opaque;
110     uint32_t value = val64;
111 
112     addr >>= 2;
113     D(qemu_log("%s addr=%x val=%x\n", __func__, addr * 4, value));
114     switch (addr)
115     {
116         case R_IAR:
117             p->regs[R_ISR] &= ~value; /* ACK.  */
118             break;
119         case R_SIE:
120             p->regs[R_IER] |= value;  /* Atomic set ie.  */
121             break;
122         case R_CIE:
123             p->regs[R_IER] &= ~value; /* Atomic clear ie.  */
124             break;
125         case R_MER:
126             p->regs[R_MER] = value & 0x3;
127             break;
128         case R_ISR:
129             if ((p->regs[R_MER] & 2)) {
130                 break;
131             }
132             /* fallthrough */
133         default:
134             if (addr < ARRAY_SIZE(p->regs))
135                 p->regs[addr] = value;
136             break;
137     }
138     update_irq(p);
139 }
140 
141 static const MemoryRegionOps pic_ops = {
142     .read = pic_read,
143     .write = pic_write,
144     .endianness = DEVICE_NATIVE_ENDIAN,
145     .valid = {
146         .min_access_size = 4,
147         .max_access_size = 4
148     }
149 };
150 
151 static void irq_handler(void *opaque, int irq, int level)
152 {
153     struct xlx_pic *p = opaque;
154 
155     /* edge triggered interrupt */
156     if (p->c_kind_of_intr & (1 << irq) && p->regs[R_MER] & 2) {
157         p->regs[R_ISR] |= (level << irq);
158     }
159 
160     p->irq_pin_state &= ~(1 << irq);
161     p->irq_pin_state |= level << irq;
162     update_irq(p);
163 }
164 
165 static void xilinx_intc_init(Object *obj)
166 {
167     struct xlx_pic *p = XILINX_INTC(obj);
168 
169     qdev_init_gpio_in(DEVICE(obj), irq_handler, 32);
170     sysbus_init_irq(SYS_BUS_DEVICE(obj), &p->parent_irq);
171 
172     memory_region_init_io(&p->mmio, obj, &pic_ops, p, "xlnx.xps-intc",
173                           R_MAX * 4);
174     sysbus_init_mmio(SYS_BUS_DEVICE(obj), &p->mmio);
175 }
176 
177 static Property xilinx_intc_properties[] = {
178     DEFINE_PROP_UINT32("kind-of-intr", struct xlx_pic, c_kind_of_intr, 0),
179     DEFINE_PROP_END_OF_LIST(),
180 };
181 
182 static void xilinx_intc_class_init(ObjectClass *klass, void *data)
183 {
184     DeviceClass *dc = DEVICE_CLASS(klass);
185 
186     dc->props = xilinx_intc_properties;
187 }
188 
189 static const TypeInfo xilinx_intc_info = {
190     .name          = TYPE_XILINX_INTC,
191     .parent        = TYPE_SYS_BUS_DEVICE,
192     .instance_size = sizeof(struct xlx_pic),
193     .instance_init = xilinx_intc_init,
194     .class_init    = xilinx_intc_class_init,
195 };
196 
197 static void xilinx_intc_register_types(void)
198 {
199     type_register_static(&xilinx_intc_info);
200 }
201 
202 type_init(xilinx_intc_register_types)
203