| /* |
| * Allwinner Watchdog emulation |
| * |
| * Copyright (C) 2023 Strahinja Jankovic <strahinja.p.jankovic@gmail.com> |
| * |
| * This file is derived from Allwinner RTC, |
| * by Niek Linnenbank. |
| * |
| * This program is free software: you can redistribute it and/or modify |
| * it under the terms of the GNU General Public License as published by |
| * the Free Software Foundation, either version 2 of the License, or |
| * (at your option) any later version. |
| * |
| * This program is distributed in the hope that it will be useful, |
| * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| * GNU General Public License for more details. |
| * |
| * You should have received a copy of the GNU General Public License |
| * along with this program. If not, see <http://www.gnu.org/licenses/>. |
| */ |
| |
| #include "qemu/osdep.h" |
| #include "qemu/log.h" |
| #include "qemu/units.h" |
| #include "qemu/module.h" |
| #include "trace.h" |
| #include "hw/sysbus.h" |
| #include "hw/registerfields.h" |
| #include "hw/watchdog/allwinner-wdt.h" |
| #include "sysemu/watchdog.h" |
| #include "migration/vmstate.h" |
| |
| /* WDT registers */ |
| enum { |
| REG_IRQ_EN = 0, /* Watchdog interrupt enable */ |
| REG_IRQ_STA, /* Watchdog interrupt status */ |
| REG_CTRL, /* Watchdog control register */ |
| REG_CFG, /* Watchdog configuration register */ |
| REG_MODE, /* Watchdog mode register */ |
| }; |
| |
| /* Universal WDT register flags */ |
| #define WDT_RESTART_MASK (1 << 0) |
| #define WDT_EN_MASK (1 << 0) |
| |
| /* sun4i specific WDT register flags */ |
| #define RST_EN_SUN4I_MASK (1 << 1) |
| #define INTV_VALUE_SUN4I_SHIFT (3) |
| #define INTV_VALUE_SUN4I_MASK (0xfu << INTV_VALUE_SUN4I_SHIFT) |
| |
| /* sun6i specific WDT register flags */ |
| #define RST_EN_SUN6I_MASK (1 << 0) |
| #define KEY_FIELD_SUN6I_SHIFT (1) |
| #define KEY_FIELD_SUN6I_MASK (0xfffu << KEY_FIELD_SUN6I_SHIFT) |
| #define KEY_FIELD_SUN6I (0xA57u) |
| #define INTV_VALUE_SUN6I_SHIFT (4) |
| #define INTV_VALUE_SUN6I_MASK (0xfu << INTV_VALUE_SUN6I_SHIFT) |
| |
| /* Map of INTV_VALUE to 0.5s units. */ |
| static const uint8_t allwinner_wdt_count_map[] = { |
| 1, |
| 2, |
| 4, |
| 6, |
| 8, |
| 10, |
| 12, |
| 16, |
| 20, |
| 24, |
| 28, |
| 32 |
| }; |
| |
| /* WDT sun4i register map (offset to name) */ |
| const uint8_t allwinner_wdt_sun4i_regmap[] = { |
| [0x0000] = REG_CTRL, |
| [0x0004] = REG_MODE, |
| }; |
| |
| /* WDT sun6i register map (offset to name) */ |
| const uint8_t allwinner_wdt_sun6i_regmap[] = { |
| [0x0000] = REG_IRQ_EN, |
| [0x0004] = REG_IRQ_STA, |
| [0x0010] = REG_CTRL, |
| [0x0014] = REG_CFG, |
| [0x0018] = REG_MODE, |
| }; |
| |
| static bool allwinner_wdt_sun4i_read(AwWdtState *s, uint32_t offset) |
| { |
| /* no sun4i specific registers currently implemented */ |
| return false; |
| } |
| |
| static bool allwinner_wdt_sun4i_write(AwWdtState *s, uint32_t offset, |
| uint32_t data) |
| { |
| /* no sun4i specific registers currently implemented */ |
| return false; |
| } |
| |
| static bool allwinner_wdt_sun4i_can_reset_system(AwWdtState *s) |
| { |
| if (s->regs[REG_MODE] & RST_EN_SUN4I_MASK) { |
| return true; |
| } else { |
| return false; |
| } |
| } |
| |
| static bool allwinner_wdt_sun4i_is_key_valid(AwWdtState *s, uint32_t val) |
| { |
| /* sun4i has no key */ |
| return true; |
| } |
| |
| static uint8_t allwinner_wdt_sun4i_get_intv_value(AwWdtState *s) |
| { |
| return ((s->regs[REG_MODE] & INTV_VALUE_SUN4I_MASK) >> |
| INTV_VALUE_SUN4I_SHIFT); |
| } |
| |
| static bool allwinner_wdt_sun6i_read(AwWdtState *s, uint32_t offset) |
| { |
| const AwWdtClass *c = AW_WDT_GET_CLASS(s); |
| |
| switch (c->regmap[offset]) { |
| case REG_IRQ_EN: |
| case REG_IRQ_STA: |
| case REG_CFG: |
| return true; |
| default: |
| break; |
| } |
| return false; |
| } |
| |
| static bool allwinner_wdt_sun6i_write(AwWdtState *s, uint32_t offset, |
| uint32_t data) |
| { |
| const AwWdtClass *c = AW_WDT_GET_CLASS(s); |
| |
| switch (c->regmap[offset]) { |
| case REG_IRQ_EN: |
| case REG_IRQ_STA: |
| case REG_CFG: |
| return true; |
| default: |
| break; |
| } |
| return false; |
| } |
| |
| static bool allwinner_wdt_sun6i_can_reset_system(AwWdtState *s) |
| { |
| if (s->regs[REG_CFG] & RST_EN_SUN6I_MASK) { |
| return true; |
| } else { |
| return false; |
| } |
| } |
| |
| static bool allwinner_wdt_sun6i_is_key_valid(AwWdtState *s, uint32_t val) |
| { |
| uint16_t key = (val & KEY_FIELD_SUN6I_MASK) >> KEY_FIELD_SUN6I_SHIFT; |
| return (key == KEY_FIELD_SUN6I); |
| } |
| |
| static uint8_t allwinner_wdt_sun6i_get_intv_value(AwWdtState *s) |
| { |
| return ((s->regs[REG_MODE] & INTV_VALUE_SUN6I_MASK) >> |
| INTV_VALUE_SUN6I_SHIFT); |
| } |
| |
| static void allwinner_wdt_update_timer(AwWdtState *s) |
| { |
| const AwWdtClass *c = AW_WDT_GET_CLASS(s); |
| uint8_t count = c->get_intv_value(s); |
| |
| ptimer_transaction_begin(s->timer); |
| ptimer_stop(s->timer); |
| |
| /* Use map to convert. */ |
| if (count < sizeof(allwinner_wdt_count_map)) { |
| ptimer_set_count(s->timer, allwinner_wdt_count_map[count]); |
| } else { |
| qemu_log_mask(LOG_GUEST_ERROR, "%s: incorrect INTV_VALUE 0x%02x\n", |
| __func__, count); |
| } |
| |
| ptimer_run(s->timer, 1); |
| ptimer_transaction_commit(s->timer); |
| |
| trace_allwinner_wdt_update_timer(count); |
| } |
| |
| static uint64_t allwinner_wdt_read(void *opaque, hwaddr offset, |
| unsigned size) |
| { |
| AwWdtState *s = AW_WDT(opaque); |
| const AwWdtClass *c = AW_WDT_GET_CLASS(s); |
| uint64_t r; |
| |
| if (offset >= c->regmap_size) { |
| qemu_log_mask(LOG_GUEST_ERROR, "%s: out-of-bounds offset 0x%04x\n", |
| __func__, (uint32_t)offset); |
| return 0; |
| } |
| |
| switch (c->regmap[offset]) { |
| case REG_CTRL: |
| case REG_MODE: |
| r = s->regs[c->regmap[offset]]; |
| break; |
| default: |
| if (!c->read(s, offset)) { |
| qemu_log_mask(LOG_UNIMP, "%s: unimplemented register 0x%04x\n", |
| __func__, (uint32_t)offset); |
| return 0; |
| } |
| r = s->regs[c->regmap[offset]]; |
| break; |
| } |
| |
| trace_allwinner_wdt_read(offset, r, size); |
| |
| return r; |
| } |
| |
| static void allwinner_wdt_write(void *opaque, hwaddr offset, |
| uint64_t val, unsigned size) |
| { |
| AwWdtState *s = AW_WDT(opaque); |
| const AwWdtClass *c = AW_WDT_GET_CLASS(s); |
| uint32_t old_val; |
| |
| if (offset >= c->regmap_size) { |
| qemu_log_mask(LOG_GUEST_ERROR, "%s: out-of-bounds offset 0x%04x\n", |
| __func__, (uint32_t)offset); |
| return; |
| } |
| |
| trace_allwinner_wdt_write(offset, val, size); |
| |
| switch (c->regmap[offset]) { |
| case REG_CTRL: |
| if (c->is_key_valid(s, val)) { |
| if (val & WDT_RESTART_MASK) { |
| /* Kick timer */ |
| allwinner_wdt_update_timer(s); |
| } |
| } |
| break; |
| case REG_MODE: |
| old_val = s->regs[REG_MODE]; |
| s->regs[REG_MODE] = (uint32_t)val; |
| |
| /* Check for rising edge on WDOG_MODE_EN */ |
| if ((s->regs[REG_MODE] & ~old_val) & WDT_EN_MASK) { |
| allwinner_wdt_update_timer(s); |
| } |
| break; |
| default: |
| if (!c->write(s, offset, val)) { |
| qemu_log_mask(LOG_UNIMP, "%s: unimplemented register 0x%04x\n", |
| __func__, (uint32_t)offset); |
| } |
| s->regs[c->regmap[offset]] = (uint32_t)val; |
| break; |
| } |
| } |
| |
| static const MemoryRegionOps allwinner_wdt_ops = { |
| .read = allwinner_wdt_read, |
| .write = allwinner_wdt_write, |
| .endianness = DEVICE_NATIVE_ENDIAN, |
| .valid = { |
| .min_access_size = 4, |
| .max_access_size = 4, |
| }, |
| .impl.min_access_size = 4, |
| }; |
| |
| static void allwinner_wdt_expired(void *opaque) |
| { |
| AwWdtState *s = AW_WDT(opaque); |
| const AwWdtClass *c = AW_WDT_GET_CLASS(s); |
| |
| bool enabled = s->regs[REG_MODE] & WDT_EN_MASK; |
| bool reset_enabled = c->can_reset_system(s); |
| |
| trace_allwinner_wdt_expired(enabled, reset_enabled); |
| |
| /* Perform watchdog action if watchdog is enabled and can trigger reset */ |
| if (enabled && reset_enabled) { |
| watchdog_perform_action(); |
| } |
| } |
| |
| static void allwinner_wdt_reset_enter(Object *obj, ResetType type) |
| { |
| AwWdtState *s = AW_WDT(obj); |
| |
| trace_allwinner_wdt_reset_enter(); |
| |
| /* Clear registers */ |
| memset(s->regs, 0, sizeof(s->regs)); |
| } |
| |
| static const VMStateDescription allwinner_wdt_vmstate = { |
| .name = "allwinner-wdt", |
| .version_id = 1, |
| .minimum_version_id = 1, |
| .fields = (const VMStateField[]) { |
| VMSTATE_PTIMER(timer, AwWdtState), |
| VMSTATE_UINT32_ARRAY(regs, AwWdtState, AW_WDT_REGS_NUM), |
| VMSTATE_END_OF_LIST() |
| } |
| }; |
| |
| static void allwinner_wdt_init(Object *obj) |
| { |
| SysBusDevice *sbd = SYS_BUS_DEVICE(obj); |
| AwWdtState *s = AW_WDT(obj); |
| const AwWdtClass *c = AW_WDT_GET_CLASS(s); |
| |
| /* Memory mapping */ |
| memory_region_init_io(&s->iomem, OBJECT(s), &allwinner_wdt_ops, s, |
| TYPE_AW_WDT, c->regmap_size * 4); |
| sysbus_init_mmio(sbd, &s->iomem); |
| } |
| |
| static void allwinner_wdt_realize(DeviceState *dev, Error **errp) |
| { |
| AwWdtState *s = AW_WDT(dev); |
| |
| s->timer = ptimer_init(allwinner_wdt_expired, s, |
| PTIMER_POLICY_NO_IMMEDIATE_TRIGGER | |
| PTIMER_POLICY_NO_IMMEDIATE_RELOAD | |
| PTIMER_POLICY_NO_COUNTER_ROUND_DOWN); |
| |
| ptimer_transaction_begin(s->timer); |
| /* Set to 2Hz (0.5s period); other periods are multiples of 0.5s. */ |
| ptimer_set_freq(s->timer, 2); |
| ptimer_set_limit(s->timer, 0xff, 1); |
| ptimer_transaction_commit(s->timer); |
| } |
| |
| static void allwinner_wdt_class_init(ObjectClass *klass, void *data) |
| { |
| DeviceClass *dc = DEVICE_CLASS(klass); |
| ResettableClass *rc = RESETTABLE_CLASS(klass); |
| |
| rc->phases.enter = allwinner_wdt_reset_enter; |
| dc->realize = allwinner_wdt_realize; |
| dc->vmsd = &allwinner_wdt_vmstate; |
| } |
| |
| static void allwinner_wdt_sun4i_class_init(ObjectClass *klass, void *data) |
| { |
| AwWdtClass *awc = AW_WDT_CLASS(klass); |
| |
| awc->regmap = allwinner_wdt_sun4i_regmap; |
| awc->regmap_size = sizeof(allwinner_wdt_sun4i_regmap); |
| awc->read = allwinner_wdt_sun4i_read; |
| awc->write = allwinner_wdt_sun4i_write; |
| awc->can_reset_system = allwinner_wdt_sun4i_can_reset_system; |
| awc->is_key_valid = allwinner_wdt_sun4i_is_key_valid; |
| awc->get_intv_value = allwinner_wdt_sun4i_get_intv_value; |
| } |
| |
| static void allwinner_wdt_sun6i_class_init(ObjectClass *klass, void *data) |
| { |
| AwWdtClass *awc = AW_WDT_CLASS(klass); |
| |
| awc->regmap = allwinner_wdt_sun6i_regmap; |
| awc->regmap_size = sizeof(allwinner_wdt_sun6i_regmap); |
| awc->read = allwinner_wdt_sun6i_read; |
| awc->write = allwinner_wdt_sun6i_write; |
| awc->can_reset_system = allwinner_wdt_sun6i_can_reset_system; |
| awc->is_key_valid = allwinner_wdt_sun6i_is_key_valid; |
| awc->get_intv_value = allwinner_wdt_sun6i_get_intv_value; |
| } |
| |
| static const TypeInfo allwinner_wdt_info = { |
| .name = TYPE_AW_WDT, |
| .parent = TYPE_SYS_BUS_DEVICE, |
| .instance_init = allwinner_wdt_init, |
| .instance_size = sizeof(AwWdtState), |
| .class_init = allwinner_wdt_class_init, |
| .class_size = sizeof(AwWdtClass), |
| .abstract = true, |
| }; |
| |
| static const TypeInfo allwinner_wdt_sun4i_info = { |
| .name = TYPE_AW_WDT_SUN4I, |
| .parent = TYPE_AW_WDT, |
| .class_init = allwinner_wdt_sun4i_class_init, |
| }; |
| |
| static const TypeInfo allwinner_wdt_sun6i_info = { |
| .name = TYPE_AW_WDT_SUN6I, |
| .parent = TYPE_AW_WDT, |
| .class_init = allwinner_wdt_sun6i_class_init, |
| }; |
| |
| static void allwinner_wdt_register(void) |
| { |
| type_register_static(&allwinner_wdt_info); |
| type_register_static(&allwinner_wdt_sun4i_info); |
| type_register_static(&allwinner_wdt_sun6i_info); |
| } |
| |
| type_init(allwinner_wdt_register) |