xref: /openbmc/qemu/hw/char/renesas_sci.c (revision 28ae3179fc52d2e4d870b635c4a412aab99759e7)
1  /*
2   * Renesas Serial Communication Interface
3   *
4   * Datasheet: RX62N Group, RX621 Group User's Manual: Hardware
5   *            (Rev.1.40 R01UH0033EJ0140)
6   *
7   * Copyright (c) 2019 Yoshinori Sato
8   *
9   * SPDX-License-Identifier: GPL-2.0-or-later
10   *
11   * This program is free software; you can redistribute it and/or modify it
12   * under the terms and conditions of the GNU General Public License,
13   * version 2 or later, as published by the Free Software Foundation.
14   *
15   * This program is distributed in the hope it will be useful, but WITHOUT
16   * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
17   * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
18   * more details.
19   *
20   * You should have received a copy of the GNU General Public License along with
21   * this program.  If not, see <http://www.gnu.org/licenses/>.
22   */
23  
24  #include "qemu/osdep.h"
25  #include "qemu/log.h"
26  #include "hw/irq.h"
27  #include "hw/registerfields.h"
28  #include "hw/qdev-properties.h"
29  #include "hw/qdev-properties-system.h"
30  #include "hw/char/renesas_sci.h"
31  #include "migration/vmstate.h"
32  
33  /* SCI register map */
34  REG8(SMR, 0)
35    FIELD(SMR, CKS,  0, 2)
36    FIELD(SMR, MP,   2, 1)
37    FIELD(SMR, STOP, 3, 1)
38    FIELD(SMR, PM,   4, 1)
39    FIELD(SMR, PE,   5, 1)
40    FIELD(SMR, CHR,  6, 1)
41    FIELD(SMR, CM,   7, 1)
42  REG8(BRR, 1)
43  REG8(SCR, 2)
44    FIELD(SCR, CKE,  0, 2)
45    FIELD(SCR, TEIE, 2, 1)
46    FIELD(SCR, MPIE, 3, 1)
47    FIELD(SCR, RE,   4, 1)
48    FIELD(SCR, TE,   5, 1)
49    FIELD(SCR, RIE,  6, 1)
50    FIELD(SCR, TIE,  7, 1)
51  REG8(TDR, 3)
52  REG8(SSR, 4)
53    FIELD(SSR, MPBT, 0, 1)
54    FIELD(SSR, MPB,  1, 1)
55    FIELD(SSR, TEND, 2, 1)
56    FIELD(SSR, ERR,  3, 3)
57      FIELD(SSR, PER,  3, 1)
58      FIELD(SSR, FER,  4, 1)
59      FIELD(SSR, ORER, 5, 1)
60    FIELD(SSR, RDRF, 6, 1)
61    FIELD(SSR, TDRE, 7, 1)
62  REG8(RDR, 5)
63  REG8(SCMR, 6)
64    FIELD(SCMR, SMIF, 0, 1)
65    FIELD(SCMR, SINV, 2, 1)
66    FIELD(SCMR, SDIR, 3, 1)
67    FIELD(SCMR, BCP2, 7, 1)
68  REG8(SEMR, 7)
69    FIELD(SEMR, ACS0, 0, 1)
70    FIELD(SEMR, ABCS, 4, 1)
71  
can_receive(void * opaque)72  static int can_receive(void *opaque)
73  {
74      RSCIState *sci = RSCI(opaque);
75      if (sci->rx_next > qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL)) {
76          return 0;
77      } else {
78          return FIELD_EX8(sci->scr, SCR, RE);
79      }
80  }
81  
receive(void * opaque,const uint8_t * buf,int size)82  static void receive(void *opaque, const uint8_t *buf, int size)
83  {
84      RSCIState *sci = RSCI(opaque);
85      sci->rx_next = qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL) + sci->trtime;
86      if (FIELD_EX8(sci->ssr, SSR, RDRF) || size > 1) {
87          sci->ssr = FIELD_DP8(sci->ssr, SSR, ORER, 1);
88          if (FIELD_EX8(sci->scr, SCR, RIE)) {
89              qemu_set_irq(sci->irq[ERI], 1);
90          }
91      } else {
92          sci->rdr = buf[0];
93          sci->ssr = FIELD_DP8(sci->ssr, SSR, RDRF, 1);
94          if (FIELD_EX8(sci->scr, SCR, RIE)) {
95              qemu_irq_pulse(sci->irq[RXI]);
96          }
97      }
98  }
99  
send_byte(RSCIState * sci)100  static void send_byte(RSCIState *sci)
101  {
102      if (qemu_chr_fe_backend_connected(&sci->chr)) {
103          qemu_chr_fe_write_all(&sci->chr, &sci->tdr, 1);
104      }
105      timer_mod(&sci->timer, qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL) + sci->trtime);
106      sci->ssr = FIELD_DP8(sci->ssr, SSR, TEND, 0);
107      sci->ssr = FIELD_DP8(sci->ssr, SSR, TDRE, 1);
108      qemu_set_irq(sci->irq[TEI], 0);
109      if (FIELD_EX8(sci->scr, SCR, TIE)) {
110          qemu_irq_pulse(sci->irq[TXI]);
111      }
112  }
113  
txend(void * opaque)114  static void txend(void *opaque)
115  {
116      RSCIState *sci = RSCI(opaque);
117      if (!FIELD_EX8(sci->ssr, SSR, TDRE)) {
118          send_byte(sci);
119      } else {
120          sci->ssr = FIELD_DP8(sci->ssr, SSR, TEND, 1);
121          if (FIELD_EX8(sci->scr, SCR, TEIE)) {
122              qemu_set_irq(sci->irq[TEI], 1);
123          }
124      }
125  }
126  
update_trtime(RSCIState * sci)127  static void update_trtime(RSCIState *sci)
128  {
129      /* char per bits */
130      sci->trtime = 8 - FIELD_EX8(sci->smr, SMR, CHR);
131      sci->trtime += FIELD_EX8(sci->smr, SMR, PE);
132      sci->trtime += FIELD_EX8(sci->smr, SMR, STOP) + 1;
133      /* x bit transmit time (32 * divrate * brr) / base freq */
134      sci->trtime *= 32 * sci->brr;
135      sci->trtime *= 1 << (2 * FIELD_EX8(sci->smr, SMR, CKS));
136      sci->trtime *= NANOSECONDS_PER_SECOND;
137      sci->trtime /= sci->input_freq;
138  }
139  
sci_is_tr_enabled(RSCIState * sci)140  static bool sci_is_tr_enabled(RSCIState *sci)
141  {
142      return FIELD_EX8(sci->scr, SCR, TE) || FIELD_EX8(sci->scr, SCR, RE);
143  }
144  
sci_write(void * opaque,hwaddr offset,uint64_t val,unsigned size)145  static void sci_write(void *opaque, hwaddr offset, uint64_t val, unsigned size)
146  {
147      RSCIState *sci = RSCI(opaque);
148  
149      switch (offset) {
150      case A_SMR:
151          if (!sci_is_tr_enabled(sci)) {
152              sci->smr = val;
153              update_trtime(sci);
154          }
155          break;
156      case A_BRR:
157          if (!sci_is_tr_enabled(sci)) {
158              sci->brr = val;
159              update_trtime(sci);
160          }
161          break;
162      case A_SCR:
163          sci->scr = val;
164          if (FIELD_EX8(sci->scr, SCR, TE)) {
165              sci->ssr = FIELD_DP8(sci->ssr, SSR, TDRE, 1);
166              sci->ssr = FIELD_DP8(sci->ssr, SSR, TEND, 1);
167              if (FIELD_EX8(sci->scr, SCR, TIE)) {
168                  qemu_irq_pulse(sci->irq[TXI]);
169              }
170          }
171          if (!FIELD_EX8(sci->scr, SCR, TEIE)) {
172              qemu_set_irq(sci->irq[TEI], 0);
173          }
174          if (!FIELD_EX8(sci->scr, SCR, RIE)) {
175              qemu_set_irq(sci->irq[ERI], 0);
176          }
177          break;
178      case A_TDR:
179          sci->tdr = val;
180          if (FIELD_EX8(sci->ssr, SSR, TEND)) {
181              send_byte(sci);
182          } else {
183              sci->ssr = FIELD_DP8(sci->ssr, SSR, TDRE, 0);
184          }
185          break;
186      case A_SSR:
187          sci->ssr = FIELD_DP8(sci->ssr, SSR, MPBT,
188                               FIELD_EX8(val, SSR, MPBT));
189          sci->ssr = FIELD_DP8(sci->ssr, SSR, ERR,
190                               FIELD_EX8(val, SSR, ERR) & 0x07);
191          if (FIELD_EX8(sci->read_ssr, SSR, ERR) &&
192              FIELD_EX8(sci->ssr, SSR, ERR) == 0) {
193              qemu_set_irq(sci->irq[ERI], 0);
194          }
195          break;
196      case A_RDR:
197          qemu_log_mask(LOG_GUEST_ERROR, "reneas_sci: RDR is read only.\n");
198          break;
199      case A_SCMR:
200          sci->scmr = val; break;
201      case A_SEMR: /* SEMR */
202          sci->semr = val; break;
203      default:
204          qemu_log_mask(LOG_UNIMP, "renesas_sci: Register 0x%" HWADDR_PRIX " "
205                                   "not implemented\n",
206                        offset);
207      }
208  }
209  
sci_read(void * opaque,hwaddr offset,unsigned size)210  static uint64_t sci_read(void *opaque, hwaddr offset, unsigned size)
211  {
212      RSCIState *sci = RSCI(opaque);
213  
214      switch (offset) {
215      case A_SMR:
216          return sci->smr;
217      case A_BRR:
218          return sci->brr;
219      case A_SCR:
220          return sci->scr;
221      case A_TDR:
222          return sci->tdr;
223      case A_SSR:
224          sci->read_ssr = sci->ssr;
225          return sci->ssr;
226      case A_RDR:
227          sci->ssr = FIELD_DP8(sci->ssr, SSR, RDRF, 0);
228          return sci->rdr;
229      case A_SCMR:
230          return sci->scmr;
231      case A_SEMR:
232          return sci->semr;
233      default:
234          qemu_log_mask(LOG_UNIMP, "renesas_sci: Register 0x%" HWADDR_PRIX
235                        " not implemented.\n", offset);
236      }
237      return UINT64_MAX;
238  }
239  
240  static const MemoryRegionOps sci_ops = {
241      .write = sci_write,
242      .read  = sci_read,
243      .endianness = DEVICE_NATIVE_ENDIAN,
244      .impl.max_access_size = 1,
245      .valid.max_access_size = 1,
246  };
247  
rsci_reset(DeviceState * dev)248  static void rsci_reset(DeviceState *dev)
249  {
250      RSCIState *sci = RSCI(dev);
251      sci->smr = sci->scr = 0x00;
252      sci->brr = 0xff;
253      sci->tdr = 0xff;
254      sci->rdr = 0x00;
255      sci->ssr = 0x84;
256      sci->scmr = 0x00;
257      sci->semr = 0x00;
258      sci->rx_next = qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL);
259  }
260  
sci_event(void * opaque,QEMUChrEvent event)261  static void sci_event(void *opaque, QEMUChrEvent event)
262  {
263      RSCIState *sci = RSCI(opaque);
264      if (event == CHR_EVENT_BREAK) {
265          sci->ssr = FIELD_DP8(sci->ssr, SSR, FER, 1);
266          if (FIELD_EX8(sci->scr, SCR, RIE)) {
267              qemu_set_irq(sci->irq[ERI], 1);
268          }
269      }
270  }
271  
rsci_realize(DeviceState * dev,Error ** errp)272  static void rsci_realize(DeviceState *dev, Error **errp)
273  {
274      RSCIState *sci = RSCI(dev);
275  
276      if (sci->input_freq == 0) {
277          qemu_log_mask(LOG_GUEST_ERROR,
278                        "renesas_sci: input-freq property must be set.");
279          return;
280      }
281      qemu_chr_fe_set_handlers(&sci->chr, can_receive, receive,
282                               sci_event, NULL, sci, NULL, true);
283  }
284  
rsci_init(Object * obj)285  static void rsci_init(Object *obj)
286  {
287      SysBusDevice *d = SYS_BUS_DEVICE(obj);
288      RSCIState *sci = RSCI(obj);
289      int i;
290  
291      memory_region_init_io(&sci->memory, OBJECT(sci), &sci_ops,
292                            sci, "renesas-sci", 0x8);
293      sysbus_init_mmio(d, &sci->memory);
294  
295      for (i = 0; i < SCI_NR_IRQ; i++) {
296          sysbus_init_irq(d, &sci->irq[i]);
297      }
298      timer_init_ns(&sci->timer, QEMU_CLOCK_VIRTUAL, txend, sci);
299  }
300  
301  static const VMStateDescription vmstate_rsci = {
302      .name = "renesas-sci",
303      .version_id = 1,
304      .minimum_version_id = 1,
305      .fields = (const VMStateField[]) {
306          VMSTATE_INT64(trtime, RSCIState),
307          VMSTATE_INT64(rx_next, RSCIState),
308          VMSTATE_UINT8(smr, RSCIState),
309          VMSTATE_UINT8(brr, RSCIState),
310          VMSTATE_UINT8(scr, RSCIState),
311          VMSTATE_UINT8(tdr, RSCIState),
312          VMSTATE_UINT8(ssr, RSCIState),
313          VMSTATE_UINT8(rdr, RSCIState),
314          VMSTATE_UINT8(scmr, RSCIState),
315          VMSTATE_UINT8(semr, RSCIState),
316          VMSTATE_UINT8(read_ssr, RSCIState),
317          VMSTATE_TIMER(timer, RSCIState),
318          VMSTATE_END_OF_LIST()
319      }
320  };
321  
322  static Property rsci_properties[] = {
323      DEFINE_PROP_UINT64("input-freq", RSCIState, input_freq, 0),
324      DEFINE_PROP_CHR("chardev", RSCIState, chr),
325      DEFINE_PROP_END_OF_LIST(),
326  };
327  
rsci_class_init(ObjectClass * klass,void * data)328  static void rsci_class_init(ObjectClass *klass, void *data)
329  {
330      DeviceClass *dc = DEVICE_CLASS(klass);
331  
332      dc->realize = rsci_realize;
333      dc->vmsd = &vmstate_rsci;
334      device_class_set_legacy_reset(dc, rsci_reset);
335      device_class_set_props(dc, rsci_properties);
336  }
337  
338  static const TypeInfo rsci_info = {
339      .name = TYPE_RENESAS_SCI,
340      .parent = TYPE_SYS_BUS_DEVICE,
341      .instance_size = sizeof(RSCIState),
342      .instance_init = rsci_init,
343      .class_init = rsci_class_init,
344  };
345  
rsci_register_types(void)346  static void rsci_register_types(void)
347  {
348      type_register_static(&rsci_info);
349  }
350  
351  type_init(rsci_register_types)
352