xref: /openbmc/qemu/hw/timer/renesas_cmt.c (revision 28ae3179fc52d2e4d870b635c4a412aab99759e7)
1  /*
2   * Renesas 16bit Compare-match timer
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/timer/renesas_cmt.h"
30  #include "migration/vmstate.h"
31  
32  /*
33   *  +0 CMSTR - common control
34   *  +2 CMCR  - ch0
35   *  +4 CMCNT - ch0
36   *  +6 CMCOR - ch0
37   *  +8 CMCR  - ch1
38   * +10 CMCNT - ch1
39   * +12 CMCOR - ch1
40   * If we think that the address of CH 0 has an offset of +2,
41   * we can treat it with the same address as CH 1, so define it like that.
42   */
43  REG16(CMSTR, 0)
44    FIELD(CMSTR, STR0, 0, 1)
45    FIELD(CMSTR, STR1, 1, 1)
46    FIELD(CMSTR, STR,  0, 2)
47  /* This addeess is channel offset */
48  REG16(CMCR, 0)
49    FIELD(CMCR, CKS,  0, 2)
50    FIELD(CMCR, CMIE, 6, 1)
51  REG16(CMCNT, 2)
52  REG16(CMCOR, 4)
53  
update_events(RCMTState * cmt,int ch)54  static void update_events(RCMTState *cmt, int ch)
55  {
56      int64_t next_time;
57  
58      if ((cmt->cmstr & (1 << ch)) == 0) {
59          /* count disable, so not happened next event. */
60          return;
61      }
62      next_time = cmt->cmcor[ch] - cmt->cmcnt[ch];
63      next_time *= NANOSECONDS_PER_SECOND;
64      next_time /= cmt->input_freq;
65      /*
66       * CKS -> div rate
67       *  0 -> 8 (1 << 3)
68       *  1 -> 32 (1 << 5)
69       *  2 -> 128 (1 << 7)
70       *  3 -> 512 (1 << 9)
71       */
72      next_time *= 1 << (3 + FIELD_EX16(cmt->cmcr[ch], CMCR, CKS) * 2);
73      next_time += qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL);
74      timer_mod(&cmt->timer[ch], next_time);
75  }
76  
read_cmcnt(RCMTState * cmt,int ch)77  static int64_t read_cmcnt(RCMTState *cmt, int ch)
78  {
79      int64_t delta, now = qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL);
80  
81      if (cmt->cmstr & (1 << ch)) {
82          delta = (now - cmt->tick[ch]);
83          delta /= NANOSECONDS_PER_SECOND;
84          delta /= cmt->input_freq;
85          delta /= 1 << (3 + FIELD_EX16(cmt->cmcr[ch], CMCR, CKS) * 2);
86          cmt->tick[ch] = now;
87          return cmt->cmcnt[ch] + delta;
88      } else {
89          return cmt->cmcnt[ch];
90      }
91  }
92  
cmt_read(void * opaque,hwaddr offset,unsigned size)93  static uint64_t cmt_read(void *opaque, hwaddr offset, unsigned size)
94  {
95      RCMTState *cmt = opaque;
96      int ch = offset / 0x08;
97      uint64_t ret;
98  
99      if (offset == A_CMSTR) {
100          ret = 0;
101          ret = FIELD_DP16(ret, CMSTR, STR,
102                           FIELD_EX16(cmt->cmstr, CMSTR, STR));
103          return ret;
104      } else {
105          offset &= 0x07;
106          if (ch == 0) {
107              offset -= 0x02;
108          }
109          switch (offset) {
110          case A_CMCR:
111              ret = 0;
112              ret = FIELD_DP16(ret, CMCR, CKS,
113                               FIELD_EX16(cmt->cmstr, CMCR, CKS));
114              ret = FIELD_DP16(ret, CMCR, CMIE,
115                               FIELD_EX16(cmt->cmstr, CMCR, CMIE));
116              return ret;
117          case A_CMCNT:
118              return read_cmcnt(cmt, ch);
119          case A_CMCOR:
120              return cmt->cmcor[ch];
121          }
122      }
123      qemu_log_mask(LOG_UNIMP, "renesas_cmt: Register 0x%" HWADDR_PRIX " "
124                               "not implemented\n",
125                    offset);
126      return UINT64_MAX;
127  }
128  
start_stop(RCMTState * cmt,int ch,int st)129  static void start_stop(RCMTState *cmt, int ch, int st)
130  {
131      if (st) {
132          update_events(cmt, ch);
133      } else {
134          timer_del(&cmt->timer[ch]);
135      }
136  }
137  
cmt_write(void * opaque,hwaddr offset,uint64_t val,unsigned size)138  static void cmt_write(void *opaque, hwaddr offset, uint64_t val, unsigned size)
139  {
140      RCMTState *cmt = opaque;
141      int ch = offset / 0x08;
142  
143      if (offset == A_CMSTR) {
144          cmt->cmstr = FIELD_EX16(val, CMSTR, STR);
145          start_stop(cmt, 0, FIELD_EX16(cmt->cmstr, CMSTR, STR0));
146          start_stop(cmt, 1, FIELD_EX16(cmt->cmstr, CMSTR, STR1));
147      } else {
148          offset &= 0x07;
149          if (ch == 0) {
150              offset -= 0x02;
151          }
152          switch (offset) {
153          case A_CMCR:
154              cmt->cmcr[ch] = FIELD_DP16(cmt->cmcr[ch], CMCR, CKS,
155                                         FIELD_EX16(val, CMCR, CKS));
156              cmt->cmcr[ch] = FIELD_DP16(cmt->cmcr[ch], CMCR, CMIE,
157                                         FIELD_EX16(val, CMCR, CMIE));
158              break;
159          case 2:
160              cmt->cmcnt[ch] = val;
161              break;
162          case 4:
163              cmt->cmcor[ch] = val;
164              break;
165          default:
166              qemu_log_mask(LOG_UNIMP, "renesas_cmt: Register 0x%" HWADDR_PRIX " "
167                                       "not implemented\n",
168                            offset);
169              return;
170          }
171          if (FIELD_EX16(cmt->cmstr, CMSTR, STR) & (1 << ch)) {
172              update_events(cmt, ch);
173          }
174      }
175  }
176  
177  static const MemoryRegionOps cmt_ops = {
178      .write = cmt_write,
179      .read  = cmt_read,
180      .endianness = DEVICE_NATIVE_ENDIAN,
181      .impl = {
182          .min_access_size = 2,
183          .max_access_size = 2,
184      },
185      .valid = {
186          .min_access_size = 2,
187          .max_access_size = 2,
188      },
189  };
190  
timer_events(RCMTState * cmt,int ch)191  static void timer_events(RCMTState *cmt, int ch)
192  {
193      cmt->cmcnt[ch] = 0;
194      cmt->tick[ch] = qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL);
195      update_events(cmt, ch);
196      if (FIELD_EX16(cmt->cmcr[ch], CMCR, CMIE)) {
197          qemu_irq_pulse(cmt->cmi[ch]);
198      }
199  }
200  
timer_event0(void * opaque)201  static void timer_event0(void *opaque)
202  {
203      RCMTState *cmt = opaque;
204  
205      timer_events(cmt, 0);
206  }
207  
timer_event1(void * opaque)208  static void timer_event1(void *opaque)
209  {
210      RCMTState *cmt = opaque;
211  
212      timer_events(cmt, 1);
213  }
214  
rcmt_reset(DeviceState * dev)215  static void rcmt_reset(DeviceState *dev)
216  {
217      RCMTState *cmt = RCMT(dev);
218      cmt->cmstr = 0;
219      cmt->cmcr[0] = cmt->cmcr[1] = 0;
220      cmt->cmcnt[0] = cmt->cmcnt[1] = 0;
221      cmt->cmcor[0] = cmt->cmcor[1] = 0xffff;
222  }
223  
rcmt_init(Object * obj)224  static void rcmt_init(Object *obj)
225  {
226      SysBusDevice *d = SYS_BUS_DEVICE(obj);
227      RCMTState *cmt = RCMT(obj);
228      int i;
229  
230      memory_region_init_io(&cmt->memory, OBJECT(cmt), &cmt_ops,
231                            cmt, "renesas-cmt", 0x10);
232      sysbus_init_mmio(d, &cmt->memory);
233  
234      for (i = 0; i < ARRAY_SIZE(cmt->cmi); i++) {
235          sysbus_init_irq(d, &cmt->cmi[i]);
236      }
237      timer_init_ns(&cmt->timer[0], QEMU_CLOCK_VIRTUAL, timer_event0, cmt);
238      timer_init_ns(&cmt->timer[1], QEMU_CLOCK_VIRTUAL, timer_event1, cmt);
239  }
240  
241  static const VMStateDescription vmstate_rcmt = {
242      .name = "rx-cmt",
243      .version_id = 1,
244      .minimum_version_id = 1,
245      .fields = (const VMStateField[]) {
246          VMSTATE_UINT16(cmstr, RCMTState),
247          VMSTATE_UINT16_ARRAY(cmcr, RCMTState, CMT_CH),
248          VMSTATE_UINT16_ARRAY(cmcnt, RCMTState, CMT_CH),
249          VMSTATE_UINT16_ARRAY(cmcor, RCMTState, CMT_CH),
250          VMSTATE_INT64_ARRAY(tick, RCMTState, CMT_CH),
251          VMSTATE_TIMER_ARRAY(timer, RCMTState, CMT_CH),
252          VMSTATE_END_OF_LIST()
253      }
254  };
255  
256  static Property rcmt_properties[] = {
257      DEFINE_PROP_UINT64("input-freq", RCMTState, input_freq, 0),
258      DEFINE_PROP_END_OF_LIST(),
259  };
260  
rcmt_class_init(ObjectClass * klass,void * data)261  static void rcmt_class_init(ObjectClass *klass, void *data)
262  {
263      DeviceClass *dc = DEVICE_CLASS(klass);
264  
265      dc->vmsd = &vmstate_rcmt;
266      device_class_set_legacy_reset(dc, rcmt_reset);
267      device_class_set_props(dc, rcmt_properties);
268  }
269  
270  static const TypeInfo rcmt_info = {
271      .name = TYPE_RENESAS_CMT,
272      .parent = TYPE_SYS_BUS_DEVICE,
273      .instance_size = sizeof(RCMTState),
274      .instance_init = rcmt_init,
275      .class_init = rcmt_class_init,
276  };
277  
rcmt_register_types(void)278  static void rcmt_register_types(void)
279  {
280      type_register_static(&rcmt_info);
281  }
282  
283  type_init(rcmt_register_types)
284