xref: /openbmc/qemu/hw/ssi/ssi.c (revision f769017d)
1 /*
2  * QEMU Synchronous Serial Interface support
3  *
4  * Copyright (c) 2009 CodeSourcery.
5  * Copyright (c) 2012 Peter A.G. Crosthwaite (peter.crosthwaite@petalogix.com)
6  * Copyright (c) 2012 PetaLogix Pty Ltd.
7  * Written by Paul Brook
8  *
9  * This code is licensed under the GNU GPL v2.
10  *
11  * Contributions after 2012-01-13 are licensed under the terms of the
12  * GNU GPL, version 2 or (at your option) any later version.
13  */
14 
15 #include "qemu/osdep.h"
16 #include "hw/qdev-properties.h"
17 #include "hw/ssi/ssi.h"
18 #include "migration/vmstate.h"
19 #include "qemu/module.h"
20 #include "qapi/error.h"
21 #include "qom/object.h"
22 
23 struct SSIBus {
24     BusState parent_obj;
25 };
26 
27 #define TYPE_SSI_BUS "SSI"
28 OBJECT_DECLARE_SIMPLE_TYPE(SSIBus, SSI_BUS)
29 
30 static const TypeInfo ssi_bus_info = {
31     .name = TYPE_SSI_BUS,
32     .parent = TYPE_BUS,
33     .instance_size = sizeof(SSIBus),
34 };
35 
36 static void ssi_cs_default(void *opaque, int n, int level)
37 {
38     SSIPeripheral *s = SSI_PERIPHERAL(opaque);
39     bool cs = !!level;
40     assert(n == 0);
41     if (s->cs != cs) {
42         if (s->spc->set_cs) {
43             s->spc->set_cs(s, cs);
44         }
45     }
46     s->cs = cs;
47 }
48 
49 static uint32_t ssi_transfer_raw_default(SSIPeripheral *dev, uint32_t val)
50 {
51     SSIPeripheralClass *ssc = dev->spc;
52 
53     if ((dev->cs && ssc->cs_polarity == SSI_CS_HIGH) ||
54         (!dev->cs && ssc->cs_polarity == SSI_CS_LOW) ||
55         ssc->cs_polarity == SSI_CS_NONE) {
56         return ssc->transfer(dev, val);
57     }
58     return 0;
59 }
60 
61 static void ssi_peripheral_realize(DeviceState *dev, Error **errp)
62 {
63     SSIPeripheral *s = SSI_PERIPHERAL(dev);
64     SSIPeripheralClass *ssc = SSI_PERIPHERAL_GET_CLASS(s);
65 
66     if (ssc->transfer_raw == ssi_transfer_raw_default &&
67             ssc->cs_polarity != SSI_CS_NONE) {
68         qdev_init_gpio_in_named(dev, ssi_cs_default, SSI_GPIO_CS, 1);
69     }
70     s->spc = ssc;
71 
72     ssc->realize(s, errp);
73 }
74 
75 static Property ssi_peripheral_properties[] = {
76     DEFINE_PROP_UINT32("addr", SSIPeripheral, addr, 0),
77     DEFINE_PROP_END_OF_LIST(),
78 };
79 
80 static void ssi_peripheral_class_init(ObjectClass *klass, void *data)
81 {
82     SSIPeripheralClass *ssc = SSI_PERIPHERAL_CLASS(klass);
83     DeviceClass *dc = DEVICE_CLASS(klass);
84 
85     dc->realize = ssi_peripheral_realize;
86     dc->bus_type = TYPE_SSI_BUS;
87     if (!ssc->transfer_raw) {
88         ssc->transfer_raw = ssi_transfer_raw_default;
89     }
90     device_class_set_props(dc, ssi_peripheral_properties);
91 }
92 
93 static const TypeInfo ssi_peripheral_info = {
94     .name = TYPE_SSI_PERIPHERAL,
95     .parent = TYPE_DEVICE,
96     .class_init = ssi_peripheral_class_init,
97     .class_size = sizeof(SSIPeripheralClass),
98     .abstract = true,
99 };
100 
101 bool ssi_realize_and_unref(DeviceState *dev, SSIBus *bus, Error **errp)
102 {
103     return qdev_realize_and_unref(dev, &bus->parent_obj, errp);
104 }
105 
106 DeviceState *ssi_create_peripheral(SSIBus *bus, const char *name)
107 {
108     DeviceState *dev = qdev_new(name);
109 
110     ssi_realize_and_unref(dev, bus, &error_fatal);
111     return dev;
112 }
113 
114 SSIBus *ssi_create_bus(DeviceState *parent, const char *name)
115 {
116     BusState *bus;
117     bus = qbus_new(TYPE_SSI_BUS, parent, name);
118     return SSI_BUS(bus);
119 }
120 
121 uint32_t ssi_transfer(SSIBus *bus, uint32_t val)
122 {
123     BusState *b = BUS(bus);
124     BusChild *kid;
125     uint32_t r = 0;
126 
127     QTAILQ_FOREACH(kid, &b->children, sibling) {
128         SSIPeripheral *p = SSI_PERIPHERAL(kid->child);
129         r |= p->spc->transfer_raw(p, val);
130     }
131 
132     return r;
133 }
134 
135 const VMStateDescription vmstate_ssi_peripheral = {
136     .name = "SSISlave",
137     .version_id = 1,
138     .minimum_version_id = 1,
139     .fields = (VMStateField[]) {
140         VMSTATE_BOOL(cs, SSIPeripheral),
141         VMSTATE_END_OF_LIST()
142     }
143 };
144 
145 static void ssi_peripheral_register_types(void)
146 {
147     type_register_static(&ssi_bus_info);
148     type_register_static(&ssi_peripheral_info);
149 }
150 
151 type_init(ssi_peripheral_register_types)
152