aboutsummaryrefslogtreecommitdiff
path: root/hw/char/goldfish_tty.c
blob: 68e261236ec85916ee0281b9a1040156f6b0f71a (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
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
/*
 * SPDX-License-Identifier: GPL-2.0-or-later
 *
 * Goldfish TTY
 *
 * (c) 2020 Laurent Vivier <laurent@vivier.eu>
 *
 */

#include "qemu/osdep.h"
#include "hw/irq.h"
#include "hw/qdev-properties-system.h"
#include "hw/sysbus.h"
#include "migration/vmstate.h"
#include "chardev/char-fe.h"
#include "qemu/log.h"
#include "trace.h"
#include "exec/address-spaces.h"
#include "sysemu/dma.h"
#include "hw/char/goldfish_tty.h"

#define GOLDFISH_TTY_VERSION 1

/* registers */

enum {
    REG_PUT_CHAR      = 0x00,
    REG_BYTES_READY   = 0x04,
    REG_CMD           = 0x08,
    REG_DATA_PTR      = 0x10,
    REG_DATA_LEN      = 0x14,
    REG_DATA_PTR_HIGH = 0x18,
    REG_VERSION       = 0x20,
};

/* commands */

enum {
    CMD_INT_DISABLE   = 0x00,
    CMD_INT_ENABLE    = 0x01,
    CMD_WRITE_BUFFER  = 0x02,
    CMD_READ_BUFFER   = 0x03,
};

static uint64_t goldfish_tty_read(void *opaque, hwaddr addr,
                                  unsigned size)
{
    GoldfishTTYState *s = opaque;
    uint64_t value = 0;

    switch (addr) {
    case REG_BYTES_READY:
        value = fifo8_num_used(&s->rx_fifo);
        break;
    case REG_VERSION:
        value = GOLDFISH_TTY_VERSION;
        break;
    default:
        qemu_log_mask(LOG_UNIMP,
                      "%s: unimplemented register read 0x%02"HWADDR_PRIx"\n",
                      __func__, addr);
        break;
    }

    trace_goldfish_tty_read(s, addr, size, value);

    return value;
}

static void goldfish_tty_cmd(GoldfishTTYState *s, uint32_t cmd)
{
    uint32_t to_copy;
    uint8_t data_out[GOLFISH_TTY_BUFFER_SIZE];
    int len;
    uint64_t ptr;

    switch (cmd) {
    case CMD_INT_DISABLE:
        if (s->int_enabled) {
            if (!fifo8_is_empty(&s->rx_fifo)) {
                qemu_set_irq(s->irq, 0);
            }
            s->int_enabled = false;
        }
        break;
    case CMD_INT_ENABLE:
        if (!s->int_enabled) {
            if (!fifo8_is_empty(&s->rx_fifo)) {
                qemu_set_irq(s->irq, 1);
            }
            s->int_enabled = true;
        }
        break;
    case CMD_WRITE_BUFFER:
        len = s->data_len;
        ptr = s->data_ptr;
        while (len) {
            to_copy = MIN(GOLFISH_TTY_BUFFER_SIZE, len);

            dma_memory_read_relaxed(&address_space_memory, ptr,
                                    data_out, to_copy);
            qemu_chr_fe_write_all(&s->chr, data_out, to_copy);

            len -= to_copy;
            ptr += to_copy;
        }
        break;
    case CMD_READ_BUFFER:
        len = s->data_len;
        ptr = s->data_ptr;
        while (len && !fifo8_is_empty(&s->rx_fifo)) {
            const uint8_t *buf = fifo8_pop_bufptr(&s->rx_fifo, len, &to_copy);

            dma_memory_write_relaxed(&address_space_memory, ptr, buf, to_copy);

            len -= to_copy;
            ptr += to_copy;
        }
        if (s->int_enabled && fifo8_is_empty(&s->rx_fifo)) {
            qemu_set_irq(s->irq, 0);
        }
        break;
    }
}

static void goldfish_tty_write(void *opaque, hwaddr addr,
                               uint64_t value, unsigned size)
{
    GoldfishTTYState *s = opaque;
    unsigned char c;

    trace_goldfish_tty_write(s, addr, size, value);

    switch (addr) {
    case REG_PUT_CHAR:
        c = value;
        qemu_chr_fe_write_all(&s->chr, &c, sizeof(c));
        break;
    case REG_CMD:
        goldfish_tty_cmd(s, value);
        break;
    case REG_DATA_PTR:
        s->data_ptr = value;
        break;
    case REG_DATA_PTR_HIGH:
        s->data_ptr = deposit64(s->data_ptr, 32, 32, value);
        break;
    case REG_DATA_LEN:
        s->data_len = value;
        break;
    default:
        qemu_log_mask(LOG_UNIMP,
                      "%s: unimplemented register write 0x%02"HWADDR_PRIx"\n",
                      __func__, addr);
        break;
    }
}

static const MemoryRegionOps goldfish_tty_ops = {
    .read = goldfish_tty_read,
    .write = goldfish_tty_write,
    .endianness = DEVICE_NATIVE_ENDIAN,
    .valid.max_access_size = 4,
    .impl.max_access_size = 4,
    .impl.min_access_size = 4,
};

static int goldfish_tty_can_receive(void *opaque)
{
    GoldfishTTYState *s = opaque;
    int available = fifo8_num_free(&s->rx_fifo);

    trace_goldfish_tty_can_receive(s, available);

    return available;
}

static void goldfish_tty_receive(void *opaque, const uint8_t *buffer, int size)
{
    GoldfishTTYState *s = opaque;

    trace_goldfish_tty_receive(s, size);

    g_assert(size <= fifo8_num_free(&s->rx_fifo));

    fifo8_push_all(&s->rx_fifo, buffer, size);

    if (s->int_enabled && !fifo8_is_empty(&s->rx_fifo)) {
        qemu_set_irq(s->irq, 1);
    }
}

static void goldfish_tty_reset(DeviceState *dev)
{
    GoldfishTTYState *s = GOLDFISH_TTY(dev);

    trace_goldfish_tty_reset(s);

    fifo8_reset(&s->rx_fifo);
    s->int_enabled = false;
    s->data_ptr = 0;
    s->data_len = 0;
}

static void goldfish_tty_realize(DeviceState *dev, Error **errp)
{
    GoldfishTTYState *s = GOLDFISH_TTY(dev);

    trace_goldfish_tty_realize(s);

    fifo8_create(&s->rx_fifo, GOLFISH_TTY_BUFFER_SIZE);
    memory_region_init_io(&s->iomem, OBJECT(s), &goldfish_tty_ops, s,
                          "goldfish_tty", 0x24);

    if (qemu_chr_fe_backend_connected(&s->chr)) {
        qemu_chr_fe_set_handlers(&s->chr, goldfish_tty_can_receive,
                                 goldfish_tty_receive, NULL, NULL,
                                 s, NULL, true);
    }
}

static void goldfish_tty_unrealize(DeviceState *dev)
{
    GoldfishTTYState *s = GOLDFISH_TTY(dev);

    trace_goldfish_tty_unrealize(s);

    fifo8_destroy(&s->rx_fifo);
}

static const VMStateDescription vmstate_goldfish_tty = {
    .name = "goldfish_tty",
    .version_id = 1,
    .minimum_version_id = 1,
    .fields = (const VMStateField[]) {
        VMSTATE_UINT32(data_len, GoldfishTTYState),
        VMSTATE_UINT64(data_ptr, GoldfishTTYState),
        VMSTATE_BOOL(int_enabled, GoldfishTTYState),
        VMSTATE_FIFO8(rx_fifo, GoldfishTTYState),
        VMSTATE_END_OF_LIST()
    }
};

static const Property goldfish_tty_properties[] = {
    DEFINE_PROP_CHR("chardev", GoldfishTTYState, chr),
    DEFINE_PROP_END_OF_LIST(),
};

static void goldfish_tty_instance_init(Object *obj)
{
    SysBusDevice *dev = SYS_BUS_DEVICE(obj);
    GoldfishTTYState *s = GOLDFISH_TTY(obj);

    trace_goldfish_tty_instance_init(s);

    sysbus_init_mmio(dev, &s->iomem);
    sysbus_init_irq(dev, &s->irq);
}

static void goldfish_tty_class_init(ObjectClass *oc, void *data)
{
    DeviceClass *dc = DEVICE_CLASS(oc);

    device_class_set_props(dc, goldfish_tty_properties);
    device_class_set_legacy_reset(dc, goldfish_tty_reset);
    dc->realize = goldfish_tty_realize;
    dc->unrealize = goldfish_tty_unrealize;
    dc->vmsd = &vmstate_goldfish_tty;
    set_bit(DEVICE_CATEGORY_INPUT, dc->categories);
}

static const TypeInfo goldfish_tty_info = {
    .name = TYPE_GOLDFISH_TTY,
    .parent = TYPE_SYS_BUS_DEVICE,
    .class_init = goldfish_tty_class_init,
    .instance_init = goldfish_tty_instance_init,
    .instance_size = sizeof(GoldfishTTYState),
};

static void goldfish_tty_register_types(void)
{
    type_register_static(&goldfish_tty_info);
}

type_init(goldfish_tty_register_types)