aboutsummaryrefslogtreecommitdiff
path: root/hw/ssi.c
blob: 2b56357153628cd8e96ce1d89ae7bb0e0c6eee8d (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
/*
 * QEMU Synchronous Serial Interface support
 *
 * Copyright (c) 2009 CodeSourcery.
 * Copyright (c) 2012 Peter A.G. Crosthwaite (peter.crosthwaite@petalogix.com)
 * Copyright (c) 2012 PetaLogix Pty Ltd.
 * Written by Paul Brook
 *
 * This code is licensed under the GNU GPL v2.
 *
 * Contributions after 2012-01-13 are licensed under the terms of the
 * GNU GPL, version 2 or (at your option) any later version.
 */

#include "ssi.h"

struct SSIBus {
    BusState qbus;
};

#define TYPE_SSI_BUS "SSI"
#define SSI_BUS(obj) OBJECT_CHECK(SSIBus, (obj), TYPE_SSI_BUS)

static const TypeInfo ssi_bus_info = {
    .name = TYPE_SSI_BUS,
    .parent = TYPE_BUS,
    .instance_size = sizeof(SSIBus),
};

static void ssi_cs_default(void *opaque, int n, int level)
{
    SSISlave *s = SSI_SLAVE(opaque);
    bool cs = !!level;
    assert(n == 0);
    if (s->cs != cs) {
        SSISlaveClass *ssc = SSI_SLAVE_GET_CLASS(s);
        if (ssc->set_cs) {
            ssc->set_cs(s, cs);
        }
    }
    s->cs = cs;
}

static uint32_t ssi_transfer_raw_default(SSISlave *dev, uint32_t val)
{
    SSISlaveClass *ssc = SSI_SLAVE_GET_CLASS(dev);

    if ((dev->cs && ssc->cs_polarity == SSI_CS_HIGH) ||
            (!dev->cs && ssc->cs_polarity == SSI_CS_LOW) ||
            ssc->cs_polarity == SSI_CS_NONE) {
        return ssc->transfer(dev, val);
    }
    return 0;
}

static int ssi_slave_init(DeviceState *dev)
{
    SSISlave *s = SSI_SLAVE(dev);
    SSISlaveClass *ssc = SSI_SLAVE_GET_CLASS(s);

    if (ssc->transfer_raw == ssi_transfer_raw_default &&
            ssc->cs_polarity != SSI_CS_NONE) {
        qdev_init_gpio_in(&s->qdev, ssi_cs_default, 1);
    }

    return ssc->init(s);
}

static void ssi_slave_class_init(ObjectClass *klass, void *data)
{
    SSISlaveClass *ssc = SSI_SLAVE_CLASS(klass);
    DeviceClass *dc = DEVICE_CLASS(klass);

    dc->init = ssi_slave_init;
    dc->bus_type = TYPE_SSI_BUS;
    if (!ssc->transfer_raw) {
        ssc->transfer_raw = ssi_transfer_raw_default;
    }
}

static TypeInfo ssi_slave_info = {
    .name = TYPE_SSI_SLAVE,
    .parent = TYPE_DEVICE,
    .class_init = ssi_slave_class_init,
    .class_size = sizeof(SSISlaveClass),
    .abstract = true,
};

DeviceState *ssi_create_slave_no_init(SSIBus *bus, const char *name)
{
    return qdev_create(&bus->qbus, name);
}

DeviceState *ssi_create_slave(SSIBus *bus, const char *name)
{
    DeviceState *dev = ssi_create_slave_no_init(bus, name);

    qdev_init_nofail(dev);
    return dev;
}

SSIBus *ssi_create_bus(DeviceState *parent, const char *name)
{
    BusState *bus;
    bus = qbus_create(TYPE_SSI_BUS, parent, name);
    return FROM_QBUS(SSIBus, bus);
}

uint32_t ssi_transfer(SSIBus *bus, uint32_t val)
{
    BusChild *kid;
    SSISlaveClass *ssc;
    uint32_t r = 0;

    QTAILQ_FOREACH(kid, &bus->qbus.children, sibling) {
        SSISlave *slave = SSI_SLAVE(kid->child);
        ssc = SSI_SLAVE_GET_CLASS(slave);
        r |= ssc->transfer_raw(slave, val);
    }

    return r;
}

const VMStateDescription vmstate_ssi_slave = {
    .name = "SSISlave",
    .version_id = 1,
    .minimum_version_id = 1,
    .minimum_version_id_old = 1,
    .fields      = (VMStateField[]) {
        VMSTATE_BOOL(cs, SSISlave),
        VMSTATE_END_OF_LIST()
    }
};

static void ssi_slave_register_types(void)
{
    type_register_static(&ssi_bus_info);
    type_register_static(&ssi_slave_info);
}

type_init(ssi_slave_register_types)

typedef struct SSIAutoConnectArg {
    qemu_irq **cs_linep;
    SSIBus *bus;
} SSIAutoConnectArg;

static int ssi_auto_connect_slave(Object *child, void *opaque)
{
    SSIAutoConnectArg *arg = opaque;
    SSISlave *dev = (SSISlave *)object_dynamic_cast(child, TYPE_SSI_SLAVE);
    qemu_irq cs_line;

    if (!dev) {
        return 0;
    }

    cs_line = qdev_get_gpio_in(DEVICE(dev), 0);
    qdev_set_parent_bus(DEVICE(dev), &arg->bus->qbus);
    **arg->cs_linep = cs_line;
    (*arg->cs_linep)++;
    return 0;
}

void ssi_auto_connect_slaves(DeviceState *parent, qemu_irq *cs_line,
                             SSIBus *bus)
{
    SSIAutoConnectArg arg = {
        .cs_linep = &cs_line,
        .bus = bus
    };

    object_child_foreach(OBJECT(parent), ssi_auto_connect_slave, &arg);
}