qemu/hw/timer/renesas_cmt.c
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   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 */
  43REG16(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 */
  48REG16(CMCR, 0)
  49  FIELD(CMCR, CKS,  0, 2)
  50  FIELD(CMCR, CMIE, 6, 1)
  51REG16(CMCNT, 2)
  52REG16(CMCOR, 4)
  53
  54static 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
  77static 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
  93static 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
 129static 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
 138static 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
 177static 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
 191static 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
 201static void timer_event0(void *opaque)
 202{
 203    RCMTState *cmt = opaque;
 204
 205    timer_events(cmt, 0);
 206}
 207
 208static void timer_event1(void *opaque)
 209{
 210    RCMTState *cmt = opaque;
 211
 212    timer_events(cmt, 1);
 213}
 214
 215static 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
 224static 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
 241static 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
 256static Property rcmt_properties[] = {
 257    DEFINE_PROP_UINT64("input-freq", RCMTState, input_freq, 0),
 258    DEFINE_PROP_END_OF_LIST(),
 259};
 260
 261static 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
 270static 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
 278static void rcmt_register_types(void)
 279{
 280    type_register_static(&rcmt_info);
 281}
 282
 283type_init(rcmt_register_types)
 284