hw/misc/sifive_e_aon.c

   1 /*
   2  * SiFive HiFive1 AON (Always On Domain) for QEMU.
   3  *
   4  * Copyright (c) 2022 SiFive, Inc. All rights reserved.
   5  *
   6  * This program is free software; you can redistribute it and/or modify it
   7  * under the terms and conditions of the GNU General Public License,
   8  * version 2 or later, as published by the Free Software Foundation.
   9  *
  10  * This program is distributed in the hope it will be useful, but WITHOUT
  11  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  12  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
  13  * more details.
  14  *
  15  * You should have received a copy of the GNU General Public License along with
  16  * this program.  If not, see <http://www.gnu.org/licenses/>.
  17  */
  18
  19 #include "qemu/osdep.h"
  20 #include "qemu/timer.h"
  21 #include "qemu/log.h"
  22 #include "hw/irq.h"
  23 #include "hw/registerfields.h"
  24 #include "hw/misc/sifive_e_aon.h"
  25 #include "qapi/visitor.h"
  26 #include "qapi/error.h"
  27 #include "sysemu/watchdog.h"
  28 #include "hw/qdev-properties.h"
  29
  30 REG32(AON_WDT_WDOGCFG, 0x0)
  31     FIELD(AON_WDT_WDOGCFG, SCALE, 0, 4)
  32     FIELD(AON_WDT_WDOGCFG, RSVD0, 4, 4)
  33     FIELD(AON_WDT_WDOGCFG, RSTEN, 8, 1)
  34     FIELD(AON_WDT_WDOGCFG, ZEROCMP, 9, 1)
  35     FIELD(AON_WDT_WDOGCFG, RSVD1, 10, 2)
  36     FIELD(AON_WDT_WDOGCFG, EN_ALWAYS, 12, 1)
  37     FIELD(AON_WDT_WDOGCFG, EN_CORE_AWAKE, 13, 1)
  38     FIELD(AON_WDT_WDOGCFG, RSVD2, 14, 14)
  39     FIELD(AON_WDT_WDOGCFG, IP0, 28, 1)
  40     FIELD(AON_WDT_WDOGCFG, RSVD3, 29, 3)
  41 REG32(AON_WDT_WDOGCOUNT, 0x8)
  42     FIELD(AON_WDT_WDOGCOUNT, VALUE, 0, 31)
  43 REG32(AON_WDT_WDOGS, 0x10)
  44 REG32(AON_WDT_WDOGFEED, 0x18)
  45 REG32(AON_WDT_WDOGKEY, 0x1c)
  46 REG32(AON_WDT_WDOGCMP0, 0x20)
  47
  48 static void sifive_e_aon_wdt_update_wdogcount(SiFiveEAONState *r)
  49 {
  50     int64_t now;
  51     if (FIELD_EX32(r->wdogcfg, AON_WDT_WDOGCFG, EN_ALWAYS) == 0 &&
  52         FIELD_EX32(r->wdogcfg, AON_WDT_WDOGCFG, EN_CORE_AWAKE) == 0) {
  53         return;
  54     }
  55
  56     now = qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL);
  57     r->wdogcount += muldiv64(now - r->wdog_restart_time,
  58                              r->wdogclk_freq, NANOSECONDS_PER_SECOND);
  59
  60     /* Clean the most significant bit. */
  61     r->wdogcount &= R_AON_WDT_WDOGCOUNT_VALUE_MASK;
  62     r->wdog_restart_time = now;
  63 }
  64
  65 static void sifive_e_aon_wdt_update_state(SiFiveEAONState *r)
  66 {
  67     uint16_t wdogs;
  68     bool cmp_signal = false;
  69     sifive_e_aon_wdt_update_wdogcount(r);
  70     wdogs = (uint16_t)(r->wdogcount >>
  71                            FIELD_EX32(r->wdogcfg, AON_WDT_WDOGCFG, SCALE));
  72
  73     if (wdogs >= r->wdogcmp0) {
  74         cmp_signal = true;
  75         if (FIELD_EX32(r->wdogcfg, AON_WDT_WDOGCFG, ZEROCMP) == 1) {
  76             r->wdogcount = 0;
  77             wdogs = 0;
  78         }
  79     }
  80
  81     if (cmp_signal) {
  82         if (FIELD_EX32(r->wdogcfg, AON_WDT_WDOGCFG, RSTEN) == 1) {
  83             watchdog_perform_action();
  84         }
  85         r->wdogcfg = FIELD_DP32(r->wdogcfg, AON_WDT_WDOGCFG, IP0, 1);
  86     }
  87
  88     qemu_set_irq(r->wdog_irq, FIELD_EX32(r->wdogcfg, AON_WDT_WDOGCFG, IP0));
  89
  90     if (wdogs < r->wdogcmp0 &&
  91         (FIELD_EX32(r->wdogcfg, AON_WDT_WDOGCFG, EN_ALWAYS) == 1 ||
  92          FIELD_EX32(r->wdogcfg, AON_WDT_WDOGCFG, EN_CORE_AWAKE) == 1)) {
  93         int64_t next = qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL);
  94         next += muldiv64((r->wdogcmp0 - wdogs) <<
  95                          FIELD_EX32(r->wdogcfg, AON_WDT_WDOGCFG, SCALE),
  96                          NANOSECONDS_PER_SECOND, r->wdogclk_freq);
  97         timer_mod(r->wdog_timer, next);
  98     } else {
  99         timer_mod(r->wdog_timer, INT64_MAX);
 100     }
 101 }
 102
 103 /*
 104  * Callback used when the timer set using timer_mod expires.
 105  */
 106 static void sifive_e_aon_wdt_expired_cb(void *opaque)
 107 {
 108     SiFiveEAONState *r = SIFIVE_E_AON(opaque);
 109     sifive_e_aon_wdt_update_state(r);
 110 }
 111
 112 static uint64_t
 113 sifive_e_aon_wdt_read(void *opaque, hwaddr addr, unsigned int size)
 114 {
 115     SiFiveEAONState *r = SIFIVE_E_AON(opaque);
 116
 117     switch (addr) {
 118     case A_AON_WDT_WDOGCFG:
 119         return r->wdogcfg;
 120     case A_AON_WDT_WDOGCOUNT:
 121         sifive_e_aon_wdt_update_wdogcount(r);
 122         return r->wdogcount;
 123     case A_AON_WDT_WDOGS:
 124         sifive_e_aon_wdt_update_wdogcount(r);
 125         return r->wdogcount >>
 126                FIELD_EX32(r->wdogcfg,
 127                           AON_WDT_WDOGCFG,
 128                           SCALE);
 129     case A_AON_WDT_WDOGFEED:
 130         return 0;
 131     case A_AON_WDT_WDOGKEY:
 132         return r->wdogunlock;
 133     case A_AON_WDT_WDOGCMP0:
 134         return r->wdogcmp0;
 135     default:
 136         qemu_log_mask(LOG_GUEST_ERROR, "%s: bad read: addr=0x%x\n",
 137                       __func__, (int)addr);
 138     }
 139
 140     return 0;
 141 }
 142
 143 static void
 144 sifive_e_aon_wdt_write(void *opaque, hwaddr addr,
 145                        uint64_t val64, unsigned int size)
 146 {
 147     SiFiveEAONState *r = SIFIVE_E_AON(opaque);
 148     uint32_t value = val64;
 149
 150     switch (addr) {
 151     case A_AON_WDT_WDOGCFG: {
 152         uint8_t new_en_always;
 153         uint8_t new_en_core_awake;
 154         uint8_t old_en_always;
 155         uint8_t old_en_core_awake;
 156         if (r->wdogunlock == 0) {
 157             return;
 158         }
 159
 160         new_en_always = FIELD_EX32(value, AON_WDT_WDOGCFG, EN_ALWAYS);
 161         new_en_core_awake = FIELD_EX32(value, AON_WDT_WDOGCFG, EN_CORE_AWAKE);
 162         old_en_always = FIELD_EX32(r->wdogcfg, AON_WDT_WDOGCFG, EN_ALWAYS);
 163         old_en_core_awake = FIELD_EX32(r->wdogcfg, AON_WDT_WDOGCFG,
 164                                        EN_CORE_AWAKE);
 165
 166         if ((old_en_always ||
 167              old_en_core_awake) == 1 &&
 168             (new_en_always ||
 169              new_en_core_awake) == 0) {
 170             sifive_e_aon_wdt_update_wdogcount(r);
 171         } else if ((old_en_always ||
 172                     old_en_core_awake) == 0 &&
 173                    (new_en_always ||
 174                     new_en_core_awake) == 1) {
 175             r->wdog_restart_time = qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL);
 176         }
 177         r->wdogcfg = value;
 178         r->wdogunlock = 0;
 179         break;
 180     }
 181     case A_AON_WDT_WDOGCOUNT:
 182         if (r->wdogunlock == 0) {
 183             return;
 184         }
 185         r->wdogcount = value & R_AON_WDT_WDOGCOUNT_VALUE_MASK;
 186         r->wdog_restart_time = qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL);
 187         r->wdogunlock = 0;
 188         break;
 189     case A_AON_WDT_WDOGS:
 190         return;
 191     case A_AON_WDT_WDOGFEED:
 192         if (r->wdogunlock == 0) {
 193             return;
 194         }
 195         if (value == SIFIVE_E_AON_WDOGFEED) {
 196             r->wdogcount = 0;
 197             r->wdog_restart_time = qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL);
 198         }
 199         r->wdogunlock = 0;
 200         break;
 201     case A_AON_WDT_WDOGKEY:
 202         if (value == SIFIVE_E_AON_WDOGKEY) {
 203             r->wdogunlock = 1;
 204         }
 205         break;
 206     case A_AON_WDT_WDOGCMP0:
 207         if (r->wdogunlock == 0) {
 208             return;
 209         }
 210         r->wdogcmp0 = (uint16_t) value;
 211         r->wdogunlock = 0;
 212         break;
 213     default:
 214         qemu_log_mask(LOG_GUEST_ERROR, "%s: bad write: addr=0x%x v=0x%x\n",
 215                       __func__, (int)addr, (int)value);
 216     }
 217     sifive_e_aon_wdt_update_state(r);
 218 }
 219
 220 static uint64_t
 221 sifive_e_aon_read(void *opaque, hwaddr addr, unsigned int size)
 222 {
 223     if (addr < SIFIVE_E_AON_RTC) {
 224         return sifive_e_aon_wdt_read(opaque, addr, size);
 225     } else if (addr < SIFIVE_E_AON_MAX) {
 226         qemu_log_mask(LOG_UNIMP, "%s: Unimplemented read: addr=0x%x\n",
 227                       __func__, (int)addr);
 228     } else {
 229         qemu_log_mask(LOG_GUEST_ERROR, "%s: bad read: addr=0x%x\n",
 230                       __func__, (int)addr);
 231     }
 232     return 0;
 233 }
 234
 235 static void
 236 sifive_e_aon_write(void *opaque, hwaddr addr,
 237                    uint64_t val64, unsigned int size)
 238 {
 239     if (addr < SIFIVE_E_AON_RTC) {
 240         sifive_e_aon_wdt_write(opaque, addr, val64, size);
 241     } else if (addr < SIFIVE_E_AON_MAX) {
 242         qemu_log_mask(LOG_UNIMP, "%s: Unimplemented write: addr=0x%x\n",
 243                       __func__, (int)addr);
 244     } else {
 245         qemu_log_mask(LOG_GUEST_ERROR, "%s: bad write: addr=0x%x\n",
 246                       __func__, (int)addr);
 247     }
 248 }
 249
 250 static const MemoryRegionOps sifive_e_aon_ops = {
 251     .read = sifive_e_aon_read,
 252     .write = sifive_e_aon_write,
 253     .endianness = DEVICE_NATIVE_ENDIAN,
 254     .impl = {
 255         .min_access_size = 4,
 256         .max_access_size = 4
 257     },
 258     .valid = {
 259         .min_access_size = 4,
 260         .max_access_size = 4
 261     }
 262 };
 263
 264 static void sifive_e_aon_reset(DeviceState *dev)
 265 {
 266     SiFiveEAONState *r = SIFIVE_E_AON(dev);
 267
 268     r->wdogcfg = FIELD_DP32(r->wdogcfg, AON_WDT_WDOGCFG, RSTEN, 0);
 269     r->wdogcfg = FIELD_DP32(r->wdogcfg, AON_WDT_WDOGCFG, EN_ALWAYS, 0);
 270     r->wdogcfg = FIELD_DP32(r->wdogcfg, AON_WDT_WDOGCFG, EN_CORE_AWAKE, 0);
 271     r->wdogcmp0 = 0xbeef;
 272
 273     sifive_e_aon_wdt_update_state(r);
 274 }
 275
 276 static void sifive_e_aon_init(Object *obj)
 277 {
 278     SysBusDevice *sbd = SYS_BUS_DEVICE(obj);
 279     SiFiveEAONState *r = SIFIVE_E_AON(obj);
 280
 281     memory_region_init_io(&r->mmio, OBJECT(r), &sifive_e_aon_ops, r,
 282                           TYPE_SIFIVE_E_AON, SIFIVE_E_AON_MAX);
 283     sysbus_init_mmio(sbd, &r->mmio);
 284
 285     /* watchdog timer */
 286     r->wdog_timer = timer_new_ns(QEMU_CLOCK_VIRTUAL,
 287                                  sifive_e_aon_wdt_expired_cb, r);
 288     r->wdogclk_freq = SIFIVE_E_LFCLK_DEFAULT_FREQ;
 289     sysbus_init_irq(sbd, &r->wdog_irq);
 290 }
 291
 292 static Property sifive_e_aon_properties[] = {
 293     DEFINE_PROP_UINT64("wdogclk-frequency", SiFiveEAONState, wdogclk_freq,
 294                        SIFIVE_E_LFCLK_DEFAULT_FREQ),
 295     DEFINE_PROP_END_OF_LIST(),
 296 };
 297
 298 static void sifive_e_aon_class_init(ObjectClass *oc, void *data)
 299 {
 300     DeviceClass *dc = DEVICE_CLASS(oc);
 301
 302     device_class_set_legacy_reset(dc, sifive_e_aon_reset);
 303     device_class_set_props(dc, sifive_e_aon_properties);
 304 }
 305
 306 static const TypeInfo sifive_e_aon_info = {
 307     .name          = TYPE_SIFIVE_E_AON,
 308     .parent        = TYPE_SYS_BUS_DEVICE,
 309     .instance_size = sizeof(SiFiveEAONState),
 310     .instance_init = sifive_e_aon_init,
 311     .class_init    = sifive_e_aon_class_init,
 312 };
 313
 314 static void sifive_e_aon_register_types(void)
 315 {
 316     type_register_static(&sifive_e_aon_info);
 317 }
 318
 319 type_init(sifive_e_aon_register_types)