xref: /openbmc/qemu/hw/char/parallel.c (revision f76b348e)
1 /*
2  * QEMU Parallel PORT emulation
3  *
4  * Copyright (c) 2003-2005 Fabrice Bellard
5  * Copyright (c) 2007 Marko Kohtala
6  *
7  * Permission is hereby granted, free of charge, to any person obtaining a copy
8  * of this software and associated documentation files (the "Software"), to deal
9  * in the Software without restriction, including without limitation the rights
10  * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
11  * copies of the Software, and to permit persons to whom the Software is
12  * furnished to do so, subject to the following conditions:
13  *
14  * The above copyright notice and this permission notice shall be included in
15  * all copies or substantial portions of the Software.
16  *
17  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
18  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
19  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
20  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
21  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
22  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
23  * THE SOFTWARE.
24  */
25 
26 #include "qemu/osdep.h"
27 #include "qapi/error.h"
28 #include "qemu/module.h"
29 #include "chardev/char-parallel.h"
30 #include "chardev/char-fe.h"
31 #include "hw/acpi/aml-build.h"
32 #include "hw/irq.h"
33 #include "hw/isa/isa.h"
34 #include "hw/qdev-properties.h"
35 #include "migration/vmstate.h"
36 #include "hw/char/parallel.h"
37 #include "sysemu/reset.h"
38 #include "sysemu/sysemu.h"
39 #include "trace.h"
40 
41 //#define DEBUG_PARALLEL
42 
43 #ifdef DEBUG_PARALLEL
44 #define pdebug(fmt, ...) printf("pp: " fmt, ## __VA_ARGS__)
45 #else
46 #define pdebug(fmt, ...) ((void)0)
47 #endif
48 
49 #define PARA_REG_DATA 0
50 #define PARA_REG_STS 1
51 #define PARA_REG_CTR 2
52 #define PARA_REG_EPP_ADDR 3
53 #define PARA_REG_EPP_DATA 4
54 
55 /*
56  * These are the definitions for the Printer Status Register
57  */
58 #define PARA_STS_BUSY	0x80	/* Busy complement */
59 #define PARA_STS_ACK	0x40	/* Acknowledge */
60 #define PARA_STS_PAPER	0x20	/* Out of paper */
61 #define PARA_STS_ONLINE	0x10	/* Online */
62 #define PARA_STS_ERROR	0x08	/* Error complement */
63 #define PARA_STS_TMOUT	0x01	/* EPP timeout */
64 
65 /*
66  * These are the definitions for the Printer Control Register
67  */
68 #define PARA_CTR_DIR	0x20	/* Direction (1=read, 0=write) */
69 #define PARA_CTR_INTEN	0x10	/* IRQ Enable */
70 #define PARA_CTR_SELECT	0x08	/* Select In complement */
71 #define PARA_CTR_INIT	0x04	/* Initialize Printer complement */
72 #define PARA_CTR_AUTOLF	0x02	/* Auto linefeed complement */
73 #define PARA_CTR_STROBE	0x01	/* Strobe complement */
74 
75 #define PARA_CTR_SIGNAL (PARA_CTR_SELECT|PARA_CTR_INIT|PARA_CTR_AUTOLF|PARA_CTR_STROBE)
76 
77 typedef struct ParallelState {
78     MemoryRegion iomem;
79     uint8_t dataw;
80     uint8_t datar;
81     uint8_t status;
82     uint8_t control;
83     qemu_irq irq;
84     int irq_pending;
85     CharBackend chr;
86     int hw_driver;
87     int epp_timeout;
88     uint32_t last_read_offset; /* For debugging */
89     /* Memory-mapped interface */
90     int it_shift;
91     PortioList portio_list;
92 } ParallelState;
93 
94 #define TYPE_ISA_PARALLEL "isa-parallel"
95 #define ISA_PARALLEL(obj) \
96     OBJECT_CHECK(ISAParallelState, (obj), TYPE_ISA_PARALLEL)
97 
98 typedef struct ISAParallelState {
99     ISADevice parent_obj;
100 
101     uint32_t index;
102     uint32_t iobase;
103     uint32_t isairq;
104     ParallelState state;
105 } ISAParallelState;
106 
107 static void parallel_update_irq(ParallelState *s)
108 {
109     if (s->irq_pending)
110         qemu_irq_raise(s->irq);
111     else
112         qemu_irq_lower(s->irq);
113 }
114 
115 static void
116 parallel_ioport_write_sw(void *opaque, uint32_t addr, uint32_t val)
117 {
118     ParallelState *s = opaque;
119 
120     addr &= 7;
121     trace_parallel_ioport_write("SW", addr, val);
122     switch(addr) {
123     case PARA_REG_DATA:
124         s->dataw = val;
125         parallel_update_irq(s);
126         break;
127     case PARA_REG_CTR:
128         val |= 0xc0;
129         if ((val & PARA_CTR_INIT) == 0 ) {
130             s->status = PARA_STS_BUSY;
131             s->status |= PARA_STS_ACK;
132             s->status |= PARA_STS_ONLINE;
133             s->status |= PARA_STS_ERROR;
134         }
135         else if (val & PARA_CTR_SELECT) {
136             if (val & PARA_CTR_STROBE) {
137                 s->status &= ~PARA_STS_BUSY;
138                 if ((s->control & PARA_CTR_STROBE) == 0)
139                     /* XXX this blocks entire thread. Rewrite to use
140                      * qemu_chr_fe_write and background I/O callbacks */
141                     qemu_chr_fe_write_all(&s->chr, &s->dataw, 1);
142             } else {
143                 if (s->control & PARA_CTR_INTEN) {
144                     s->irq_pending = 1;
145                 }
146             }
147         }
148         parallel_update_irq(s);
149         s->control = val;
150         break;
151     }
152 }
153 
154 static void parallel_ioport_write_hw(void *opaque, uint32_t addr, uint32_t val)
155 {
156     ParallelState *s = opaque;
157     uint8_t parm = val;
158     int dir;
159 
160     /* Sometimes programs do several writes for timing purposes on old
161        HW. Take care not to waste time on writes that do nothing. */
162 
163     s->last_read_offset = ~0U;
164 
165     addr &= 7;
166     trace_parallel_ioport_write("HW", addr, val);
167     switch(addr) {
168     case PARA_REG_DATA:
169         if (s->dataw == val)
170             return;
171         pdebug("wd%02x\n", val);
172         qemu_chr_fe_ioctl(&s->chr, CHR_IOCTL_PP_WRITE_DATA, &parm);
173         s->dataw = val;
174         break;
175     case PARA_REG_STS:
176         pdebug("ws%02x\n", val);
177         if (val & PARA_STS_TMOUT)
178             s->epp_timeout = 0;
179         break;
180     case PARA_REG_CTR:
181         val |= 0xc0;
182         if (s->control == val)
183             return;
184         pdebug("wc%02x\n", val);
185 
186         if ((val & PARA_CTR_DIR) != (s->control & PARA_CTR_DIR)) {
187             if (val & PARA_CTR_DIR) {
188                 dir = 1;
189             } else {
190                 dir = 0;
191             }
192             qemu_chr_fe_ioctl(&s->chr, CHR_IOCTL_PP_DATA_DIR, &dir);
193             parm &= ~PARA_CTR_DIR;
194         }
195 
196         qemu_chr_fe_ioctl(&s->chr, CHR_IOCTL_PP_WRITE_CONTROL, &parm);
197         s->control = val;
198         break;
199     case PARA_REG_EPP_ADDR:
200         if ((s->control & (PARA_CTR_DIR|PARA_CTR_SIGNAL)) != PARA_CTR_INIT)
201             /* Controls not correct for EPP address cycle, so do nothing */
202             pdebug("wa%02x s\n", val);
203         else {
204             struct ParallelIOArg ioarg = { .buffer = &parm, .count = 1 };
205             if (qemu_chr_fe_ioctl(&s->chr,
206                                   CHR_IOCTL_PP_EPP_WRITE_ADDR, &ioarg)) {
207                 s->epp_timeout = 1;
208                 pdebug("wa%02x t\n", val);
209             }
210             else
211                 pdebug("wa%02x\n", val);
212         }
213         break;
214     case PARA_REG_EPP_DATA:
215         if ((s->control & (PARA_CTR_DIR|PARA_CTR_SIGNAL)) != PARA_CTR_INIT)
216             /* Controls not correct for EPP data cycle, so do nothing */
217             pdebug("we%02x s\n", val);
218         else {
219             struct ParallelIOArg ioarg = { .buffer = &parm, .count = 1 };
220             if (qemu_chr_fe_ioctl(&s->chr, CHR_IOCTL_PP_EPP_WRITE, &ioarg)) {
221                 s->epp_timeout = 1;
222                 pdebug("we%02x t\n", val);
223             }
224             else
225                 pdebug("we%02x\n", val);
226         }
227         break;
228     }
229 }
230 
231 static void
232 parallel_ioport_eppdata_write_hw2(void *opaque, uint32_t addr, uint32_t val)
233 {
234     ParallelState *s = opaque;
235     uint16_t eppdata = cpu_to_le16(val);
236     int err;
237     struct ParallelIOArg ioarg = {
238         .buffer = &eppdata, .count = sizeof(eppdata)
239     };
240 
241     trace_parallel_ioport_write("EPP", addr, val);
242     if ((s->control & (PARA_CTR_DIR|PARA_CTR_SIGNAL)) != PARA_CTR_INIT) {
243         /* Controls not correct for EPP data cycle, so do nothing */
244         pdebug("we%04x s\n", val);
245         return;
246     }
247     err = qemu_chr_fe_ioctl(&s->chr, CHR_IOCTL_PP_EPP_WRITE, &ioarg);
248     if (err) {
249         s->epp_timeout = 1;
250         pdebug("we%04x t\n", val);
251     }
252     else
253         pdebug("we%04x\n", val);
254 }
255 
256 static void
257 parallel_ioport_eppdata_write_hw4(void *opaque, uint32_t addr, uint32_t val)
258 {
259     ParallelState *s = opaque;
260     uint32_t eppdata = cpu_to_le32(val);
261     int err;
262     struct ParallelIOArg ioarg = {
263         .buffer = &eppdata, .count = sizeof(eppdata)
264     };
265 
266     trace_parallel_ioport_write("EPP", addr, val);
267     if ((s->control & (PARA_CTR_DIR|PARA_CTR_SIGNAL)) != PARA_CTR_INIT) {
268         /* Controls not correct for EPP data cycle, so do nothing */
269         pdebug("we%08x s\n", val);
270         return;
271     }
272     err = qemu_chr_fe_ioctl(&s->chr, CHR_IOCTL_PP_EPP_WRITE, &ioarg);
273     if (err) {
274         s->epp_timeout = 1;
275         pdebug("we%08x t\n", val);
276     }
277     else
278         pdebug("we%08x\n", val);
279 }
280 
281 static uint32_t parallel_ioport_read_sw(void *opaque, uint32_t addr)
282 {
283     ParallelState *s = opaque;
284     uint32_t ret = 0xff;
285 
286     addr &= 7;
287     switch(addr) {
288     case PARA_REG_DATA:
289         if (s->control & PARA_CTR_DIR)
290             ret = s->datar;
291         else
292             ret = s->dataw;
293         break;
294     case PARA_REG_STS:
295         ret = s->status;
296         s->irq_pending = 0;
297         if ((s->status & PARA_STS_BUSY) == 0 && (s->control & PARA_CTR_STROBE) == 0) {
298             /* XXX Fixme: wait 5 microseconds */
299             if (s->status & PARA_STS_ACK)
300                 s->status &= ~PARA_STS_ACK;
301             else {
302                 /* XXX Fixme: wait 5 microseconds */
303                 s->status |= PARA_STS_ACK;
304                 s->status |= PARA_STS_BUSY;
305             }
306         }
307         parallel_update_irq(s);
308         break;
309     case PARA_REG_CTR:
310         ret = s->control;
311         break;
312     }
313     trace_parallel_ioport_read("SW", addr, ret);
314     return ret;
315 }
316 
317 static uint32_t parallel_ioport_read_hw(void *opaque, uint32_t addr)
318 {
319     ParallelState *s = opaque;
320     uint8_t ret = 0xff;
321     addr &= 7;
322     switch(addr) {
323     case PARA_REG_DATA:
324         qemu_chr_fe_ioctl(&s->chr, CHR_IOCTL_PP_READ_DATA, &ret);
325         if (s->last_read_offset != addr || s->datar != ret)
326             pdebug("rd%02x\n", ret);
327         s->datar = ret;
328         break;
329     case PARA_REG_STS:
330         qemu_chr_fe_ioctl(&s->chr, CHR_IOCTL_PP_READ_STATUS, &ret);
331         ret &= ~PARA_STS_TMOUT;
332         if (s->epp_timeout)
333             ret |= PARA_STS_TMOUT;
334         if (s->last_read_offset != addr || s->status != ret)
335             pdebug("rs%02x\n", ret);
336         s->status = ret;
337         break;
338     case PARA_REG_CTR:
339         /* s->control has some bits fixed to 1. It is zero only when
340            it has not been yet written to.  */
341         if (s->control == 0) {
342             qemu_chr_fe_ioctl(&s->chr, CHR_IOCTL_PP_READ_CONTROL, &ret);
343             if (s->last_read_offset != addr)
344                 pdebug("rc%02x\n", ret);
345             s->control = ret;
346         }
347         else {
348             ret = s->control;
349             if (s->last_read_offset != addr)
350                 pdebug("rc%02x\n", ret);
351         }
352         break;
353     case PARA_REG_EPP_ADDR:
354         if ((s->control & (PARA_CTR_DIR | PARA_CTR_SIGNAL)) !=
355             (PARA_CTR_DIR | PARA_CTR_INIT))
356             /* Controls not correct for EPP addr cycle, so do nothing */
357             pdebug("ra%02x s\n", ret);
358         else {
359             struct ParallelIOArg ioarg = { .buffer = &ret, .count = 1 };
360             if (qemu_chr_fe_ioctl(&s->chr,
361                                   CHR_IOCTL_PP_EPP_READ_ADDR, &ioarg)) {
362                 s->epp_timeout = 1;
363                 pdebug("ra%02x t\n", ret);
364             }
365             else
366                 pdebug("ra%02x\n", ret);
367         }
368         break;
369     case PARA_REG_EPP_DATA:
370         if ((s->control & (PARA_CTR_DIR | PARA_CTR_SIGNAL)) !=
371             (PARA_CTR_DIR | PARA_CTR_INIT))
372             /* Controls not correct for EPP data cycle, so do nothing */
373             pdebug("re%02x s\n", ret);
374         else {
375             struct ParallelIOArg ioarg = { .buffer = &ret, .count = 1 };
376             if (qemu_chr_fe_ioctl(&s->chr, CHR_IOCTL_PP_EPP_READ, &ioarg)) {
377                 s->epp_timeout = 1;
378                 pdebug("re%02x t\n", ret);
379             }
380             else
381                 pdebug("re%02x\n", ret);
382         }
383         break;
384     }
385     trace_parallel_ioport_read("HW", addr, ret);
386     s->last_read_offset = addr;
387     return ret;
388 }
389 
390 static uint32_t
391 parallel_ioport_eppdata_read_hw2(void *opaque, uint32_t addr)
392 {
393     ParallelState *s = opaque;
394     uint32_t ret;
395     uint16_t eppdata = ~0;
396     int err;
397     struct ParallelIOArg ioarg = {
398         .buffer = &eppdata, .count = sizeof(eppdata)
399     };
400     if ((s->control & (PARA_CTR_DIR|PARA_CTR_SIGNAL)) != (PARA_CTR_DIR|PARA_CTR_INIT)) {
401         /* Controls not correct for EPP data cycle, so do nothing */
402         pdebug("re%04x s\n", eppdata);
403         return eppdata;
404     }
405     err = qemu_chr_fe_ioctl(&s->chr, CHR_IOCTL_PP_EPP_READ, &ioarg);
406     ret = le16_to_cpu(eppdata);
407 
408     if (err) {
409         s->epp_timeout = 1;
410         pdebug("re%04x t\n", ret);
411     }
412     else
413         pdebug("re%04x\n", ret);
414     trace_parallel_ioport_read("EPP", addr, ret);
415     return ret;
416 }
417 
418 static uint32_t
419 parallel_ioport_eppdata_read_hw4(void *opaque, uint32_t addr)
420 {
421     ParallelState *s = opaque;
422     uint32_t ret;
423     uint32_t eppdata = ~0U;
424     int err;
425     struct ParallelIOArg ioarg = {
426         .buffer = &eppdata, .count = sizeof(eppdata)
427     };
428     if ((s->control & (PARA_CTR_DIR|PARA_CTR_SIGNAL)) != (PARA_CTR_DIR|PARA_CTR_INIT)) {
429         /* Controls not correct for EPP data cycle, so do nothing */
430         pdebug("re%08x s\n", eppdata);
431         return eppdata;
432     }
433     err = qemu_chr_fe_ioctl(&s->chr, CHR_IOCTL_PP_EPP_READ, &ioarg);
434     ret = le32_to_cpu(eppdata);
435 
436     if (err) {
437         s->epp_timeout = 1;
438         pdebug("re%08x t\n", ret);
439     }
440     else
441         pdebug("re%08x\n", ret);
442     trace_parallel_ioport_read("EPP", addr, ret);
443     return ret;
444 }
445 
446 static void parallel_ioport_ecp_write(void *opaque, uint32_t addr, uint32_t val)
447 {
448     trace_parallel_ioport_write("ECP", addr & 7, val);
449     pdebug("wecp%d=%02x\n", addr & 7, val);
450 }
451 
452 static uint32_t parallel_ioport_ecp_read(void *opaque, uint32_t addr)
453 {
454     uint8_t ret = 0xff;
455 
456     trace_parallel_ioport_read("ECP", addr & 7, ret);
457     pdebug("recp%d:%02x\n", addr & 7, ret);
458     return ret;
459 }
460 
461 static void parallel_reset(void *opaque)
462 {
463     ParallelState *s = opaque;
464 
465     s->datar = ~0;
466     s->dataw = ~0;
467     s->status = PARA_STS_BUSY;
468     s->status |= PARA_STS_ACK;
469     s->status |= PARA_STS_ONLINE;
470     s->status |= PARA_STS_ERROR;
471     s->status |= PARA_STS_TMOUT;
472     s->control = PARA_CTR_SELECT;
473     s->control |= PARA_CTR_INIT;
474     s->control |= 0xc0;
475     s->irq_pending = 0;
476     s->hw_driver = 0;
477     s->epp_timeout = 0;
478     s->last_read_offset = ~0U;
479 }
480 
481 static const int isa_parallel_io[MAX_PARALLEL_PORTS] = { 0x378, 0x278, 0x3bc };
482 
483 static const MemoryRegionPortio isa_parallel_portio_hw_list[] = {
484     { 0, 8, 1,
485       .read = parallel_ioport_read_hw,
486       .write = parallel_ioport_write_hw },
487     { 4, 1, 2,
488       .read = parallel_ioport_eppdata_read_hw2,
489       .write = parallel_ioport_eppdata_write_hw2 },
490     { 4, 1, 4,
491       .read = parallel_ioport_eppdata_read_hw4,
492       .write = parallel_ioport_eppdata_write_hw4 },
493     { 0x400, 8, 1,
494       .read = parallel_ioport_ecp_read,
495       .write = parallel_ioport_ecp_write },
496     PORTIO_END_OF_LIST(),
497 };
498 
499 static const MemoryRegionPortio isa_parallel_portio_sw_list[] = {
500     { 0, 8, 1,
501       .read = parallel_ioport_read_sw,
502       .write = parallel_ioport_write_sw },
503     PORTIO_END_OF_LIST(),
504 };
505 
506 
507 static const VMStateDescription vmstate_parallel_isa = {
508     .name = "parallel_isa",
509     .version_id = 1,
510     .minimum_version_id = 1,
511     .fields      = (VMStateField[]) {
512         VMSTATE_UINT8(state.dataw, ISAParallelState),
513         VMSTATE_UINT8(state.datar, ISAParallelState),
514         VMSTATE_UINT8(state.status, ISAParallelState),
515         VMSTATE_UINT8(state.control, ISAParallelState),
516         VMSTATE_INT32(state.irq_pending, ISAParallelState),
517         VMSTATE_INT32(state.epp_timeout, ISAParallelState),
518         VMSTATE_END_OF_LIST()
519     }
520 };
521 
522 static int parallel_can_receive(void *opaque)
523 {
524      return 1;
525 }
526 
527 static void parallel_isa_realizefn(DeviceState *dev, Error **errp)
528 {
529     static int index;
530     ISADevice *isadev = ISA_DEVICE(dev);
531     ISAParallelState *isa = ISA_PARALLEL(dev);
532     ParallelState *s = &isa->state;
533     int base;
534     uint8_t dummy;
535 
536     if (!qemu_chr_fe_backend_connected(&s->chr)) {
537         error_setg(errp, "Can't create parallel device, empty char device");
538         return;
539     }
540 
541     if (isa->index == -1) {
542         isa->index = index;
543     }
544     if (isa->index >= MAX_PARALLEL_PORTS) {
545         error_setg(errp, "Max. supported number of parallel ports is %d.",
546                    MAX_PARALLEL_PORTS);
547         return;
548     }
549     if (isa->iobase == -1) {
550         isa->iobase = isa_parallel_io[isa->index];
551     }
552     index++;
553 
554     base = isa->iobase;
555     isa_init_irq(isadev, &s->irq, isa->isairq);
556     qemu_register_reset(parallel_reset, s);
557 
558     qemu_chr_fe_set_handlers(&s->chr, parallel_can_receive, NULL,
559                              NULL, NULL, s, NULL, true);
560     if (qemu_chr_fe_ioctl(&s->chr, CHR_IOCTL_PP_READ_STATUS, &dummy) == 0) {
561         s->hw_driver = 1;
562         s->status = dummy;
563     }
564 
565     isa_register_portio_list(isadev, &s->portio_list, base,
566                              (s->hw_driver
567                               ? &isa_parallel_portio_hw_list[0]
568                               : &isa_parallel_portio_sw_list[0]),
569                              s, "parallel");
570 }
571 
572 static void parallel_isa_build_aml(ISADevice *isadev, Aml *scope)
573 {
574     ISAParallelState *isa = ISA_PARALLEL(isadev);
575     Aml *dev;
576     Aml *crs;
577 
578     crs = aml_resource_template();
579     aml_append(crs, aml_io(AML_DECODE16, isa->iobase, isa->iobase, 0x08, 0x08));
580     aml_append(crs, aml_irq_no_flags(isa->isairq));
581 
582     dev = aml_device("LPT%d", isa->index + 1);
583     aml_append(dev, aml_name_decl("_HID", aml_eisaid("PNP0400")));
584     aml_append(dev, aml_name_decl("_UID", aml_int(isa->index + 1)));
585     aml_append(dev, aml_name_decl("_STA", aml_int(0xf)));
586     aml_append(dev, aml_name_decl("_CRS", crs));
587 
588     aml_append(scope, dev);
589 }
590 
591 /* Memory mapped interface */
592 static uint64_t parallel_mm_readfn(void *opaque, hwaddr addr, unsigned size)
593 {
594     ParallelState *s = opaque;
595 
596     return parallel_ioport_read_sw(s, addr >> s->it_shift) &
597         MAKE_64BIT_MASK(0, size * 8);
598 }
599 
600 static void parallel_mm_writefn(void *opaque, hwaddr addr,
601                                 uint64_t value, unsigned size)
602 {
603     ParallelState *s = opaque;
604 
605     parallel_ioport_write_sw(s, addr >> s->it_shift,
606                              value & MAKE_64BIT_MASK(0, size * 8));
607 }
608 
609 static const MemoryRegionOps parallel_mm_ops = {
610     .read = parallel_mm_readfn,
611     .write = parallel_mm_writefn,
612     .valid.min_access_size = 1,
613     .valid.max_access_size = 4,
614     .endianness = DEVICE_NATIVE_ENDIAN,
615 };
616 
617 /* If fd is zero, it means that the parallel device uses the console */
618 bool parallel_mm_init(MemoryRegion *address_space,
619                       hwaddr base, int it_shift, qemu_irq irq,
620                       Chardev *chr)
621 {
622     ParallelState *s;
623 
624     s = g_malloc0(sizeof(ParallelState));
625     s->irq = irq;
626     qemu_chr_fe_init(&s->chr, chr, &error_abort);
627     s->it_shift = it_shift;
628     qemu_register_reset(parallel_reset, s);
629 
630     memory_region_init_io(&s->iomem, NULL, &parallel_mm_ops, s,
631                           "parallel", 8 << it_shift);
632     memory_region_add_subregion(address_space, base, &s->iomem);
633     return true;
634 }
635 
636 static Property parallel_isa_properties[] = {
637     DEFINE_PROP_UINT32("index", ISAParallelState, index,   -1),
638     DEFINE_PROP_UINT32("iobase", ISAParallelState, iobase,  -1),
639     DEFINE_PROP_UINT32("irq",   ISAParallelState, isairq,  7),
640     DEFINE_PROP_CHR("chardev",  ISAParallelState, state.chr),
641     DEFINE_PROP_END_OF_LIST(),
642 };
643 
644 static void parallel_isa_class_initfn(ObjectClass *klass, void *data)
645 {
646     DeviceClass *dc = DEVICE_CLASS(klass);
647     ISADeviceClass *isa = ISA_DEVICE_CLASS(klass);
648 
649     dc->realize = parallel_isa_realizefn;
650     dc->vmsd = &vmstate_parallel_isa;
651     isa->build_aml = parallel_isa_build_aml;
652     device_class_set_props(dc, parallel_isa_properties);
653     set_bit(DEVICE_CATEGORY_INPUT, dc->categories);
654 }
655 
656 static const TypeInfo parallel_isa_info = {
657     .name          = TYPE_ISA_PARALLEL,
658     .parent        = TYPE_ISA_DEVICE,
659     .instance_size = sizeof(ISAParallelState),
660     .class_init    = parallel_isa_class_initfn,
661 };
662 
663 static void parallel_register_types(void)
664 {
665     type_register_static(&parallel_isa_info);
666 }
667 
668 type_init(parallel_register_types)
669