hw/timer/renesas_cmt.c

   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
  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
  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
  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
 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
 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
 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
 201 static void timer_event0(void *opaque)
 202 {
 203     RCMTState *cmt = opaque;
 204
 205     timer_events(cmt, 0);
 206 }
 207
 208 static void timer_event1(void *opaque)
 209 {
 210     RCMTState *cmt = opaque;
 211
 212     timer_events(cmt, 1);
 213 }
 214
 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
 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 = (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
 261 static void rcmt_class_init(ObjectClass *klass, void *data)
 262 {
 263     DeviceClass *dc = DEVICE_CLASS(klass);
 264
 265     dc->vmsd = &vmstate_rcmt;
 266     dc->reset = 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
 278 static void rcmt_register_types(void)
 279 {
 280     type_register_static(&rcmt_info);
 281 }
 282
 283 type_init(rcmt_register_types)