1/*
2 * QEMU GE IP-Octal 232 IndustryPack emulation
3 *
4 * Copyright (C) 2012 Igalia, S.L.
5 * Author: Alberto Garcia <berto@igalia.com>
6 *
7 * This code is licensed under the GNU GPL v2 or (at your option) any
8 * later version.
9 */
10
11#include "qemu/osdep.h"
12#include "hw/ipack/ipack.h"
13#include "hw/irq.h"
14#include "hw/qdev-properties.h"
15#include "migration/vmstate.h"
16#include "qemu/bitops.h"
17#include "qemu/module.h"
18#include "chardev/char-fe.h"
19
20/* #define DEBUG_IPOCTAL */
21
22#ifdef DEBUG_IPOCTAL
23#define DPRINTF2(fmt, ...) \
24 do { fprintf(stderr, fmt, ## __VA_ARGS__); } while (0)
25#else
26#define DPRINTF2(fmt, ...) do { } while (0)
27#endif
28
29#define DPRINTF(fmt, ...) DPRINTF2("IP-Octal: " fmt, ## __VA_ARGS__)
30
31#define RX_FIFO_SIZE 3
32
33/* The IP-Octal has 8 channels (a-h)
34 divided into 4 blocks (A-D) */
35#define N_CHANNELS 8
36#define N_BLOCKS 4
37
38#define REG_MRa 0x01
39#define REG_MRb 0x11
40#define REG_SRa 0x03
41#define REG_SRb 0x13
42#define REG_CSRa 0x03
43#define REG_CSRb 0x13
44#define REG_CRa 0x05
45#define REG_CRb 0x15
46#define REG_RHRa 0x07
47#define REG_RHRb 0x17
48#define REG_THRa 0x07
49#define REG_THRb 0x17
50#define REG_ACR 0x09
51#define REG_ISR 0x0B
52#define REG_IMR 0x0B
53#define REG_OPCR 0x1B
54
55#define CR_ENABLE_RX BIT(0)
56#define CR_DISABLE_RX BIT(1)
57#define CR_ENABLE_TX BIT(2)
58#define CR_DISABLE_TX BIT(3)
59#define CR_CMD(cr) ((cr) >> 4)
60#define CR_NO_OP 0
61#define CR_RESET_MR 1
62#define CR_RESET_RX 2
63#define CR_RESET_TX 3
64#define CR_RESET_ERR 4
65#define CR_RESET_BRKINT 5
66#define CR_START_BRK 6
67#define CR_STOP_BRK 7
68#define CR_ASSERT_RTSN 8
69#define CR_NEGATE_RTSN 9
70#define CR_TIMEOUT_ON 10
71#define CR_TIMEOUT_OFF 12
72
73#define SR_RXRDY BIT(0)
74#define SR_FFULL BIT(1)
75#define SR_TXRDY BIT(2)
76#define SR_TXEMT BIT(3)
77#define SR_OVERRUN BIT(4)
78#define SR_PARITY BIT(5)
79#define SR_FRAMING BIT(6)
80#define SR_BREAK BIT(7)
81
82#define ISR_TXRDYA BIT(0)
83#define ISR_RXRDYA BIT(1)
84#define ISR_BREAKA BIT(2)
85#define ISR_CNTRDY BIT(3)
86#define ISR_TXRDYB BIT(4)
87#define ISR_RXRDYB BIT(5)
88#define ISR_BREAKB BIT(6)
89#define ISR_MPICHG BIT(7)
90#define ISR_TXRDY(CH) (((CH) & 1) ? BIT(4) : BIT(0))
91#define ISR_RXRDY(CH) (((CH) & 1) ? BIT(5) : BIT(1))
92#define ISR_BREAK(CH) (((CH) & 1) ? BIT(6) : BIT(2))
93
94typedef struct IPOctalState IPOctalState;
95typedef struct SCC2698Channel SCC2698Channel;
96typedef struct SCC2698Block SCC2698Block;
97
98struct SCC2698Channel {
99 IPOctalState *ipoctal;
100 CharBackend dev;
101 bool rx_enabled;
102 uint8_t mr[2];
103 uint8_t mr_idx;
104 uint8_t sr;
105 uint8_t rhr[RX_FIFO_SIZE];
106 uint8_t rhr_idx;
107 uint8_t rx_pending;
108};
109
110struct SCC2698Block {
111 uint8_t imr;
112 uint8_t isr;
113};
114
115struct IPOctalState {
116 IPackDevice parent_obj;
117
118 SCC2698Channel ch[N_CHANNELS];
119 SCC2698Block blk[N_BLOCKS];
120 uint8_t irq_vector;
121};
122
123#define TYPE_IPOCTAL "ipoctal232"
124
125#define IPOCTAL(obj) \
126 OBJECT_CHECK(IPOctalState, (obj), TYPE_IPOCTAL)
127
128static const VMStateDescription vmstate_scc2698_channel = {
129 .name = "scc2698_channel",
130 .version_id = 1,
131 .minimum_version_id = 1,
132 .fields = (VMStateField[]) {
133 VMSTATE_BOOL(rx_enabled, SCC2698Channel),
134 VMSTATE_UINT8_ARRAY(mr, SCC2698Channel, 2),
135 VMSTATE_UINT8(mr_idx, SCC2698Channel),
136 VMSTATE_UINT8(sr, SCC2698Channel),
137 VMSTATE_UINT8_ARRAY(rhr, SCC2698Channel, RX_FIFO_SIZE),
138 VMSTATE_UINT8(rhr_idx, SCC2698Channel),
139 VMSTATE_UINT8(rx_pending, SCC2698Channel),
140 VMSTATE_END_OF_LIST()
141 }
142};
143
144static const VMStateDescription vmstate_scc2698_block = {
145 .name = "scc2698_block",
146 .version_id = 1,
147 .minimum_version_id = 1,
148 .fields = (VMStateField[]) {
149 VMSTATE_UINT8(imr, SCC2698Block),
150 VMSTATE_UINT8(isr, SCC2698Block),
151 VMSTATE_END_OF_LIST()
152 }
153};
154
155static const VMStateDescription vmstate_ipoctal = {
156 .name = "ipoctal232",
157 .version_id = 1,
158 .minimum_version_id = 1,
159 .fields = (VMStateField[]) {
160 VMSTATE_IPACK_DEVICE(parent_obj, IPOctalState),
161 VMSTATE_STRUCT_ARRAY(ch, IPOctalState, N_CHANNELS, 1,
162 vmstate_scc2698_channel, SCC2698Channel),
163 VMSTATE_STRUCT_ARRAY(blk, IPOctalState, N_BLOCKS, 1,
164 vmstate_scc2698_block, SCC2698Block),
165 VMSTATE_UINT8(irq_vector, IPOctalState),
166 VMSTATE_END_OF_LIST()
167 }
168};
169
170/* data[10] is 0x0C, not 0x0B as the doc says */
171static const uint8_t id_prom_data[] = {
172 0x49, 0x50, 0x41, 0x43, 0xF0, 0x22,
173 0xA1, 0x00, 0x00, 0x00, 0x0C, 0xCC
174};
175
176static void update_irq(IPOctalState *dev, unsigned block)
177{
178 IPackDevice *idev = IPACK_DEVICE(dev);
179 /* Blocks A and B interrupt on INT0#, C and D on INT1#.
180 Thus, to get the status we have to check two blocks. */
181 SCC2698Block *blk0 = &dev->blk[block];
182 SCC2698Block *blk1 = &dev->blk[block^1];
183 unsigned intno = block / 2;
184
185 if ((blk0->isr & blk0->imr) || (blk1->isr & blk1->imr)) {
186 qemu_irq_raise(idev->irq[intno]);
187 } else {
188 qemu_irq_lower(idev->irq[intno]);
189 }
190}
191
192static void write_cr(IPOctalState *dev, unsigned channel, uint8_t val)
193{
194 SCC2698Channel *ch = &dev->ch[channel];
195 SCC2698Block *blk = &dev->blk[channel / 2];
196
197 DPRINTF("Write CR%c %u: ", channel + 'a', val);
198
199 /* The lower 4 bits are used to enable and disable Tx and Rx */
200 if (val & CR_ENABLE_RX) {
201 DPRINTF2("Rx on, ");
202 ch->rx_enabled = true;
203 }
204 if (val & CR_DISABLE_RX) {
205 DPRINTF2("Rx off, ");
206 ch->rx_enabled = false;
207 }
208 if (val & CR_ENABLE_TX) {
209 DPRINTF2("Tx on, ");
210 ch->sr |= SR_TXRDY | SR_TXEMT;
211 blk->isr |= ISR_TXRDY(channel);
212 }
213 if (val & CR_DISABLE_TX) {
214 DPRINTF2("Tx off, ");
215 ch->sr &= ~(SR_TXRDY | SR_TXEMT);
216 blk->isr &= ~ISR_TXRDY(channel);
217 }
218
219 DPRINTF2("cmd: ");
220
221 /* The rest of the bits implement different commands */
222 switch (CR_CMD(val)) {
223 case CR_NO_OP:
224 DPRINTF2("none");
225 break;
226 case CR_RESET_MR:
227 DPRINTF2("reset MR");
228 ch->mr_idx = 0;
229 break;
230 case CR_RESET_RX:
231 DPRINTF2("reset Rx");
232 ch->rx_enabled = false;
233 ch->rx_pending = 0;
234 ch->sr &= ~SR_RXRDY;
235 blk->isr &= ~ISR_RXRDY(channel);
236 break;
237 case CR_RESET_TX:
238 DPRINTF2("reset Tx");
239 ch->sr &= ~(SR_TXRDY | SR_TXEMT);
240 blk->isr &= ~ISR_TXRDY(channel);
241 break;
242 case CR_RESET_ERR:
243 DPRINTF2("reset err");
244 ch->sr &= ~(SR_OVERRUN | SR_PARITY | SR_FRAMING | SR_BREAK);
245 break;
246 case CR_RESET_BRKINT:
247 DPRINTF2("reset brk ch int");
248 blk->isr &= ~(ISR_BREAKA | ISR_BREAKB);
249 break;
250 default:
251 DPRINTF2("unsupported 0x%x", CR_CMD(val));
252 }
253
254 DPRINTF2("\n");
255}
256
257static uint16_t io_read(IPackDevice *ip, uint8_t addr)
258{
259 IPOctalState *dev = IPOCTAL(ip);
260 uint16_t ret = 0;
261 /* addr[7:6]: block (A-D)
262 addr[7:5]: channel (a-h)
263 addr[5:0]: register */
264 unsigned block = addr >> 5;
265 unsigned channel = addr >> 4;
266 /* Big endian, accessed using 8-bit bytes at odd locations */
267 unsigned offset = (addr & 0x1F) ^ 1;
268 SCC2698Channel *ch = &dev->ch[channel];
269 SCC2698Block *blk = &dev->blk[block];
270 uint8_t old_isr = blk->isr;
271
272 switch (offset) {
273
274 case REG_MRa:
275 case REG_MRb:
276 ret = ch->mr[ch->mr_idx];
277 DPRINTF("Read MR%u%c: 0x%x\n", ch->mr_idx + 1, channel + 'a', ret);
278 ch->mr_idx = 1;
279 break;
280
281 case REG_SRa:
282 case REG_SRb:
283 ret = ch->sr;
284 DPRINTF("Read SR%c: 0x%x\n", channel + 'a', ret);
285 break;
286
287 case REG_RHRa:
288 case REG_RHRb:
289 ret = ch->rhr[ch->rhr_idx];
290 if (ch->rx_pending > 0) {
291 ch->rx_pending--;
292 if (ch->rx_pending == 0) {
293 ch->sr &= ~SR_RXRDY;
294 blk->isr &= ~ISR_RXRDY(channel);
295 qemu_chr_fe_accept_input(&ch->dev);
296 } else {
297 ch->rhr_idx = (ch->rhr_idx + 1) % RX_FIFO_SIZE;
298 }
299 if (ch->sr & SR_BREAK) {
300 ch->sr &= ~SR_BREAK;
301 blk->isr |= ISR_BREAK(channel);
302 }
303 }
304 DPRINTF("Read RHR%c (0x%x)\n", channel + 'a', ret);
305 break;
306
307 case REG_ISR:
308 ret = blk->isr;
309 DPRINTF("Read ISR%c: 0x%x\n", block + 'A', ret);
310 break;
311
312 default:
313 DPRINTF("Read unknown/unsupported register 0x%02x\n", offset);
314 }
315
316 if (old_isr != blk->isr) {
317 update_irq(dev, block);
318 }
319
320 return ret;
321}
322
323static void io_write(IPackDevice *ip, uint8_t addr, uint16_t val)
324{
325 IPOctalState *dev = IPOCTAL(ip);
326 unsigned reg = val & 0xFF;
327 /* addr[7:6]: block (A-D)
328 addr[7:5]: channel (a-h)
329 addr[5:0]: register */
330 unsigned block = addr >> 5;
331 unsigned channel = addr >> 4;
332 /* Big endian, accessed using 8-bit bytes at odd locations */
333 unsigned offset = (addr & 0x1F) ^ 1;
334 SCC2698Channel *ch = &dev->ch[channel];
335 SCC2698Block *blk = &dev->blk[block];
336 uint8_t old_isr = blk->isr;
337 uint8_t old_imr = blk->imr;
338
339 switch (offset) {
340
341 case REG_MRa:
342 case REG_MRb:
343 ch->mr[ch->mr_idx] = reg;
344 DPRINTF("Write MR%u%c 0x%x\n", ch->mr_idx + 1, channel + 'a', reg);
345 ch->mr_idx = 1;
346 break;
347
348 /* Not implemented */
349 case REG_CSRa:
350 case REG_CSRb:
351 DPRINTF("Write CSR%c: 0x%x\n", channel + 'a', reg);
352 break;
353
354 case REG_CRa:
355 case REG_CRb:
356 write_cr(dev, channel, reg);
357 break;
358
359 case REG_THRa:
360 case REG_THRb:
361 if (ch->sr & SR_TXRDY) {
362 uint8_t thr = reg;
363 DPRINTF("Write THR%c (0x%x)\n", channel + 'a', reg);
364 /* XXX this blocks entire thread. Rewrite to use
365 * qemu_chr_fe_write and background I/O callbacks */
366 qemu_chr_fe_write_all(&ch->dev, &thr, 1);
367 } else {
368 DPRINTF("Write THR%c (0x%x), Tx disabled\n", channel + 'a', reg);
369 }
370 break;
371
372 /* Not implemented */
373 case REG_ACR:
374 DPRINTF("Write ACR%c 0x%x\n", block + 'A', val);
375 break;
376
377 case REG_IMR:
378 DPRINTF("Write IMR%c 0x%x\n", block + 'A', val);
379 blk->imr = reg;
380 break;
381
382 /* Not implemented */
383 case REG_OPCR:
384 DPRINTF("Write OPCR%c 0x%x\n", block + 'A', val);
385 break;
386
387 default:
388 DPRINTF("Write unknown/unsupported register 0x%02x %u\n", offset, val);
389 }
390
391 if (old_isr != blk->isr || old_imr != blk->imr) {
392 update_irq(dev, block);
393 }
394}
395
396static uint16_t id_read(IPackDevice *ip, uint8_t addr)
397{
398 uint16_t ret = 0;
399 unsigned pos = addr / 2; /* The ID PROM data is stored every other byte */
400
401 if (pos < ARRAY_SIZE(id_prom_data)) {
402 ret = id_prom_data[pos];
403 } else {
404 DPRINTF("Attempt to read unavailable PROM data at 0x%x\n", addr);
405 }
406
407 return ret;
408}
409
410static void id_write(IPackDevice *ip, uint8_t addr, uint16_t val)
411{
412 IPOctalState *dev = IPOCTAL(ip);
413 if (addr == 1) {
414 DPRINTF("Write IRQ vector: %u\n", (unsigned) val);
415 dev->irq_vector = val; /* Undocumented, but the hw works like that */
416 } else {
417 DPRINTF("Attempt to write 0x%x to 0x%x\n", val, addr);
418 }
419}
420
421static uint16_t int_read(IPackDevice *ip, uint8_t addr)
422{
423 IPOctalState *dev = IPOCTAL(ip);
424 /* Read address 0 to ACK INT0# and address 2 to ACK INT1# */
425 if (addr != 0 && addr != 2) {
426 DPRINTF("Attempt to read from 0x%x\n", addr);
427 return 0;
428 } else {
429 /* Update interrupts if necessary */
430 update_irq(dev, addr);
431 return dev->irq_vector;
432 }
433}
434
435static void int_write(IPackDevice *ip, uint8_t addr, uint16_t val)
436{
437 DPRINTF("Attempt to write 0x%x to 0x%x\n", val, addr);
438}
439
440static uint16_t mem_read16(IPackDevice *ip, uint32_t addr)
441{
442 DPRINTF("Attempt to read from 0x%x\n", addr);
443 return 0;
444}
445
446static void mem_write16(IPackDevice *ip, uint32_t addr, uint16_t val)
447{
448 DPRINTF("Attempt to write 0x%x to 0x%x\n", val, addr);
449}
450
451static uint8_t mem_read8(IPackDevice *ip, uint32_t addr)
452{
453 DPRINTF("Attempt to read from 0x%x\n", addr);
454 return 0;
455}
456
457static void mem_write8(IPackDevice *ip, uint32_t addr, uint8_t val)
458{
459 IPOctalState *dev = IPOCTAL(ip);
460 if (addr == 1) {
461 DPRINTF("Write IRQ vector: %u\n", (unsigned) val);
462 dev->irq_vector = val;
463 } else {
464 DPRINTF("Attempt to write 0x%x to 0x%x\n", val, addr);
465 }
466}
467
468static int hostdev_can_receive(void *opaque)
469{
470 SCC2698Channel *ch = opaque;
471 int available_bytes = RX_FIFO_SIZE - ch->rx_pending;
472 return ch->rx_enabled ? available_bytes : 0;
473}
474
475static void hostdev_receive(void *opaque, const uint8_t *buf, int size)
476{
477 SCC2698Channel *ch = opaque;
478 IPOctalState *dev = ch->ipoctal;
479 unsigned pos = ch->rhr_idx + ch->rx_pending;
480 int i;
481
482 assert(size + ch->rx_pending <= RX_FIFO_SIZE);
483
484 /* Copy data to the RxFIFO */
485 for (i = 0; i < size; i++) {
486 pos %= RX_FIFO_SIZE;
487 ch->rhr[pos++] = buf[i];
488 }
489
490 ch->rx_pending += size;
491
492 /* If the RxFIFO was empty raise an interrupt */
493 if (!(ch->sr & SR_RXRDY)) {
494 unsigned block, channel = 0;
495 /* Find channel number to update the ISR register */
496 while (&dev->ch[channel] != ch) {
497 channel++;
498 }
499 block = channel / 2;
500 dev->blk[block].isr |= ISR_RXRDY(channel);
501 ch->sr |= SR_RXRDY;
502 update_irq(dev, block);
503 }
504}
505
506static void hostdev_event(void *opaque, int event)
507{
508 SCC2698Channel *ch = opaque;
509 switch (event) {
510 case CHR_EVENT_OPENED:
511 DPRINTF("Device %s opened\n", ch->dev->label);
512 break;
513 case CHR_EVENT_BREAK: {
514 uint8_t zero = 0;
515 DPRINTF("Device %s received break\n", ch->dev->label);
516
517 if (!(ch->sr & SR_BREAK)) {
518 IPOctalState *dev = ch->ipoctal;
519 unsigned block, channel = 0;
520
521 while (&dev->ch[channel] != ch) {
522 channel++;
523 }
524 block = channel / 2;
525
526 ch->sr |= SR_BREAK;
527 dev->blk[block].isr |= ISR_BREAK(channel);
528 }
529
530 /* Put a zero character in the buffer */
531 hostdev_receive(ch, &zero, 1);
532 }
533 break;
534 default:
535 DPRINTF("Device %s received event %d\n", ch->dev->label, event);
536 }
537}
538
539static void ipoctal_realize(DeviceState *dev, Error **errp)
540{
541 IPOctalState *s = IPOCTAL(dev);
542 unsigned i;
543
544 for (i = 0; i < N_CHANNELS; i++) {
545 SCC2698Channel *ch = &s->ch[i];
546 ch->ipoctal = s;
547
548 /* Redirect IP-Octal channels to host character devices */
549 if (qemu_chr_fe_backend_connected(&ch->dev)) {
550 qemu_chr_fe_set_handlers(&ch->dev, hostdev_can_receive,
551 hostdev_receive, hostdev_event,
552 NULL, ch, NULL, true);
553 DPRINTF("Redirecting channel %u to %s\n", i, ch->dev->label);
554 } else {
555 DPRINTF("Could not redirect channel %u, no chardev set\n", i);
556 }
557 }
558}
559
560static Property ipoctal_properties[] = {
561 DEFINE_PROP_CHR("chardev0", IPOctalState, ch[0].dev),
562 DEFINE_PROP_CHR("chardev1", IPOctalState, ch[1].dev),
563 DEFINE_PROP_CHR("chardev2", IPOctalState, ch[2].dev),
564 DEFINE_PROP_CHR("chardev3", IPOctalState, ch[3].dev),
565 DEFINE_PROP_CHR("chardev4", IPOctalState, ch[4].dev),
566 DEFINE_PROP_CHR("chardev5", IPOctalState, ch[5].dev),
567 DEFINE_PROP_CHR("chardev6", IPOctalState, ch[6].dev),
568 DEFINE_PROP_CHR("chardev7", IPOctalState, ch[7].dev),
569 DEFINE_PROP_END_OF_LIST(),
570};
571
572static void ipoctal_class_init(ObjectClass *klass, void *data)
573{
574 DeviceClass *dc = DEVICE_CLASS(klass);
575 IPackDeviceClass *ic = IPACK_DEVICE_CLASS(klass);
576
577 ic->realize = ipoctal_realize;
578 ic->io_read = io_read;
579 ic->io_write = io_write;
580 ic->id_read = id_read;
581 ic->id_write = id_write;
582 ic->int_read = int_read;
583 ic->int_write = int_write;
584 ic->mem_read16 = mem_read16;
585 ic->mem_write16 = mem_write16;
586 ic->mem_read8 = mem_read8;
587 ic->mem_write8 = mem_write8;
588
589 set_bit(DEVICE_CATEGORY_INPUT, dc->categories);
590 dc->desc = "GE IP-Octal 232 8-channel RS-232 IndustryPack";
591 dc->props = ipoctal_properties;
592 dc->vmsd = &vmstate_ipoctal;
593}
594
595static const TypeInfo ipoctal_info = {
596 .name = TYPE_IPOCTAL,
597 .parent = TYPE_IPACK_DEVICE,
598 .instance_size = sizeof(IPOctalState),
599 .class_init = ipoctal_class_init,
600};
601
602static void ipoctal_register_types(void)
603{
604 type_register_static(&ipoctal_info);
605}
606
607type_init(ipoctal_register_types)
608