summaryrefslogtreecommitdiff
path: root/hw/char/sh_serial.c
blob: 303eb0a678d3a5e4488c87efc034861b916ddb0e (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
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
/*
 * QEMU SCI/SCIF serial port emulation
 *
 * Copyright (c) 2007 Magnus Damm
 *
 * Based on serial.c - QEMU 16450 UART emulation
 * Copyright (c) 2003-2004 Fabrice Bellard
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 * THE SOFTWARE.
 */
#include "qemu/osdep.h"
#include "hw/hw.h"
#include "hw/sh4/sh.h"
#include "sysemu/char.h"
#include "exec/address-spaces.h"
#include "qapi/error.h"

//#define DEBUG_SERIAL

#define SH_SERIAL_FLAG_TEND (1 << 0)
#define SH_SERIAL_FLAG_TDE  (1 << 1)
#define SH_SERIAL_FLAG_RDF  (1 << 2)
#define SH_SERIAL_FLAG_BRK  (1 << 3)
#define SH_SERIAL_FLAG_DR   (1 << 4)

#define SH_RX_FIFO_LENGTH (16)

typedef struct {
    MemoryRegion iomem;
    MemoryRegion iomem_p4;
    MemoryRegion iomem_a7;
    uint8_t smr;
    uint8_t brr;
    uint8_t scr;
    uint8_t dr; /* ftdr / tdr */
    uint8_t sr; /* fsr / ssr */
    uint16_t fcr;
    uint8_t sptr;

    uint8_t rx_fifo[SH_RX_FIFO_LENGTH]; /* frdr / rdr */
    uint8_t rx_cnt;
    uint8_t rx_tail;
    uint8_t rx_head;

    int freq;
    int feat;
    int flags;
    int rtrg;

    CharBackend chr;

    qemu_irq eri;
    qemu_irq rxi;
    qemu_irq txi;
    qemu_irq tei;
    qemu_irq bri;
} sh_serial_state;

static void sh_serial_clear_fifo(sh_serial_state * s)
{
    memset(s->rx_fifo, 0, SH_RX_FIFO_LENGTH);
    s->rx_cnt = 0;
    s->rx_head = 0;
    s->rx_tail = 0;
}

static void sh_serial_write(void *opaque, hwaddr offs,
                            uint64_t val, unsigned size)
{
    sh_serial_state *s = opaque;
    unsigned char ch;

#ifdef DEBUG_SERIAL
    printf("sh_serial: write offs=0x%02x val=0x%02x\n",
	   offs, val);
#endif
    switch(offs) {
    case 0x00: /* SMR */
        s->smr = val & ((s->feat & SH_SERIAL_FEAT_SCIF) ? 0x7b : 0xff);
        return;
    case 0x04: /* BRR */
        s->brr = val;
	return;
    case 0x08: /* SCR */
        /* TODO : For SH7751, SCIF mask should be 0xfb. */
        s->scr = val & ((s->feat & SH_SERIAL_FEAT_SCIF) ? 0xfa : 0xff);
        if (!(val & (1 << 5)))
            s->flags |= SH_SERIAL_FLAG_TEND;
        if ((s->feat & SH_SERIAL_FEAT_SCIF) && s->txi) {
	    qemu_set_irq(s->txi, val & (1 << 7));
        }
        if (!(val & (1 << 6))) {
	    qemu_set_irq(s->rxi, 0);
        }
        return;
    case 0x0c: /* FTDR / TDR */
        if (qemu_chr_fe_get_driver(&s->chr)) {
            ch = val;
            /* XXX this blocks entire thread. Rewrite to use
             * qemu_chr_fe_write and background I/O callbacks */
            qemu_chr_fe_write_all(&s->chr, &ch, 1);
	}
	s->dr = val;
	s->flags &= ~SH_SERIAL_FLAG_TDE;
        return;
#if 0
    case 0x14: /* FRDR / RDR */
        ret = 0;
        break;
#endif
    }
    if (s->feat & SH_SERIAL_FEAT_SCIF) {
        switch(offs) {
        case 0x10: /* FSR */
            if (!(val & (1 << 6)))
                s->flags &= ~SH_SERIAL_FLAG_TEND;
            if (!(val & (1 << 5)))
                s->flags &= ~SH_SERIAL_FLAG_TDE;
            if (!(val & (1 << 4)))
                s->flags &= ~SH_SERIAL_FLAG_BRK;
            if (!(val & (1 << 1)))
                s->flags &= ~SH_SERIAL_FLAG_RDF;
            if (!(val & (1 << 0)))
                s->flags &= ~SH_SERIAL_FLAG_DR;

            if (!(val & (1 << 1)) || !(val & (1 << 0))) {
                if (s->rxi) {
                    qemu_set_irq(s->rxi, 0);
                }
            }
            return;
        case 0x18: /* FCR */
            s->fcr = val;
            switch ((val >> 6) & 3) {
            case 0:
                s->rtrg = 1;
                break;
            case 1:
                s->rtrg = 4;
                break;
            case 2:
                s->rtrg = 8;
                break;
            case 3:
                s->rtrg = 14;
                break;
            }
            if (val & (1 << 1)) {
                sh_serial_clear_fifo(s);
                s->sr &= ~(1 << 1);
            }

            return;
        case 0x20: /* SPTR */
            s->sptr = val & 0xf3;
            return;
        case 0x24: /* LSR */
            return;
        }
    }
    else {
        switch(offs) {
#if 0
        case 0x0c:
            ret = s->dr;
            break;
        case 0x10:
            ret = 0;
            break;
#endif
        case 0x1c:
            s->sptr = val & 0x8f;
            return;
        }
    }

    fprintf(stderr, "sh_serial: unsupported write to 0x%02"
            HWADDR_PRIx "\n", offs);
    abort();
}

static uint64_t sh_serial_read(void *opaque, hwaddr offs,
                               unsigned size)
{
    sh_serial_state *s = opaque;
    uint32_t ret = ~0;

#if 0
    switch(offs) {
    case 0x00:
        ret = s->smr;
        break;
    case 0x04:
        ret = s->brr;
	break;
    case 0x08:
        ret = s->scr;
        break;
    case 0x14:
        ret = 0;
        break;
    }
#endif
    if (s->feat & SH_SERIAL_FEAT_SCIF) {
        switch(offs) {
        case 0x00: /* SMR */
            ret = s->smr;
            break;
        case 0x08: /* SCR */
            ret = s->scr;
            break;
        case 0x10: /* FSR */
            ret = 0;
            if (s->flags & SH_SERIAL_FLAG_TEND)
                ret |= (1 << 6);
            if (s->flags & SH_SERIAL_FLAG_TDE)
                ret |= (1 << 5);
            if (s->flags & SH_SERIAL_FLAG_BRK)
                ret |= (1 << 4);
            if (s->flags & SH_SERIAL_FLAG_RDF)
                ret |= (1 << 1);
            if (s->flags & SH_SERIAL_FLAG_DR)
                ret |= (1 << 0);

            if (s->scr & (1 << 5))
                s->flags |= SH_SERIAL_FLAG_TDE | SH_SERIAL_FLAG_TEND;

            break;
        case 0x14:
            if (s->rx_cnt > 0) {
                ret = s->rx_fifo[s->rx_tail++];
                s->rx_cnt--;
                if (s->rx_tail == SH_RX_FIFO_LENGTH)
                    s->rx_tail = 0;
                if (s->rx_cnt < s->rtrg)
                    s->flags &= ~SH_SERIAL_FLAG_RDF;
            }
            break;
        case 0x18:
            ret = s->fcr;
            break;
        case 0x1c:
            ret = s->rx_cnt;
            break;
        case 0x20:
            ret = s->sptr;
            break;
        case 0x24:
            ret = 0;
            break;
        }
    }
    else {
        switch(offs) {
#if 0
        case 0x0c:
            ret = s->dr;
            break;
        case 0x10:
            ret = 0;
            break;
        case 0x14:
            ret = s->rx_fifo[0];
            break;
#endif
        case 0x1c:
            ret = s->sptr;
            break;
        }
    }
#ifdef DEBUG_SERIAL
    printf("sh_serial: read offs=0x%02x val=0x%x\n",
	   offs, ret);
#endif

    if (ret & ~((1 << 16) - 1)) {
        fprintf(stderr, "sh_serial: unsupported read from 0x%02"
                HWADDR_PRIx "\n", offs);
        abort();
    }

    return ret;
}

static int sh_serial_can_receive(sh_serial_state *s)
{
    return s->scr & (1 << 4);
}

static void sh_serial_receive_break(sh_serial_state *s)
{
    if (s->feat & SH_SERIAL_FEAT_SCIF)
        s->sr |= (1 << 4);
}

static int sh_serial_can_receive1(void *opaque)
{
    sh_serial_state *s = opaque;
    return sh_serial_can_receive(s);
}

static void sh_serial_receive1(void *opaque, const uint8_t *buf, int size)
{
    sh_serial_state *s = opaque;

    if (s->feat & SH_SERIAL_FEAT_SCIF) {
        int i;
        for (i = 0; i < size; i++) {
            if (s->rx_cnt < SH_RX_FIFO_LENGTH) {
                s->rx_fifo[s->rx_head++] = buf[i];
                if (s->rx_head == SH_RX_FIFO_LENGTH) {
                    s->rx_head = 0;
                }
                s->rx_cnt++;
                if (s->rx_cnt >= s->rtrg) {
                    s->flags |= SH_SERIAL_FLAG_RDF;
                    if (s->scr & (1 << 6) && s->rxi) {
                        qemu_set_irq(s->rxi, 1);
                    }
                }
            }
        }
    } else {
        s->rx_fifo[0] = buf[0];
    }
}

static void sh_serial_event(void *opaque, int event)
{
    sh_serial_state *s = opaque;
    if (event == CHR_EVENT_BREAK)
        sh_serial_receive_break(s);
}

static const MemoryRegionOps sh_serial_ops = {
    .read = sh_serial_read,
    .write = sh_serial_write,
    .endianness = DEVICE_NATIVE_ENDIAN,
};

void sh_serial_init(MemoryRegion *sysmem,
                    hwaddr base, int feat,
                    uint32_t freq, Chardev *chr,
                    qemu_irq eri_source,
                    qemu_irq rxi_source,
                    qemu_irq txi_source,
                    qemu_irq tei_source,
                    qemu_irq bri_source)
{
    sh_serial_state *s;

    s = g_malloc0(sizeof(sh_serial_state));

    s->feat = feat;
    s->flags = SH_SERIAL_FLAG_TEND | SH_SERIAL_FLAG_TDE;
    s->rtrg = 1;

    s->smr = 0;
    s->brr = 0xff;
    s->scr = 1 << 5; /* pretend that TX is enabled so early printk works */
    s->sptr = 0;

    if (feat & SH_SERIAL_FEAT_SCIF) {
        s->fcr = 0;
    }
    else {
        s->dr = 0xff;
    }

    sh_serial_clear_fifo(s);

    memory_region_init_io(&s->iomem, NULL, &sh_serial_ops, s,
                          "serial", 0x100000000ULL);

    memory_region_init_alias(&s->iomem_p4, NULL, "serial-p4", &s->iomem,
                             0, 0x28);
    memory_region_add_subregion(sysmem, P4ADDR(base), &s->iomem_p4);

    memory_region_init_alias(&s->iomem_a7, NULL, "serial-a7", &s->iomem,
                             0, 0x28);
    memory_region_add_subregion(sysmem, A7ADDR(base), &s->iomem_a7);

    if (chr) {
        qemu_chr_fe_init(&s->chr, chr, &error_abort);
        qemu_chr_fe_set_handlers(&s->chr, sh_serial_can_receive1,
                                 sh_serial_receive1,
                                 sh_serial_event, s, NULL, true);
    }

    s->eri = eri_source;
    s->rxi = rxi_source;
    s->txi = txi_source;
    s->tei = tei_source;
    s->bri = bri_source;
}