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-rw-r--r--hw/watchdog/Kconfig4
-rw-r--r--hw/watchdog/allwinner-wdt.c416
-rw-r--r--hw/watchdog/meson.build1
-rw-r--r--hw/watchdog/trace-events7
-rw-r--r--include/hw/watchdog/allwinner-wdt.h123
5 files changed, 551 insertions, 0 deletions
diff --git a/hw/watchdog/Kconfig b/hw/watchdog/Kconfig
index 66e1d029e3..861fd00334 100644
--- a/hw/watchdog/Kconfig
+++ b/hw/watchdog/Kconfig
@@ -20,3 +20,7 @@ config WDT_IMX2
 
 config WDT_SBSA
     bool
+
+config ALLWINNER_WDT
+    bool
+    select PTIMER
diff --git a/hw/watchdog/allwinner-wdt.c b/hw/watchdog/allwinner-wdt.c
new file mode 100644
index 0000000000..6205765efe
--- /dev/null
+++ b/hw/watchdog/allwinner-wdt.c
@@ -0,0 +1,416 @@
+/*
+ * 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 = (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)
diff --git a/hw/watchdog/meson.build b/hw/watchdog/meson.build
index 8974b5cf4c..5dcd4fbe2f 100644
--- a/hw/watchdog/meson.build
+++ b/hw/watchdog/meson.build
@@ -1,4 +1,5 @@
 softmmu_ss.add(files('watchdog.c'))
+softmmu_ss.add(when: 'CONFIG_ALLWINNER_WDT', if_true: files('allwinner-wdt.c'))
 softmmu_ss.add(when: 'CONFIG_CMSDK_APB_WATCHDOG', if_true: files('cmsdk-apb-watchdog.c'))
 softmmu_ss.add(when: 'CONFIG_WDT_IB6300ESB', if_true: files('wdt_i6300esb.c'))
 softmmu_ss.add(when: 'CONFIG_WDT_IB700', if_true: files('wdt_ib700.c'))
diff --git a/hw/watchdog/trace-events b/hw/watchdog/trace-events
index 54371ae075..2739570652 100644
--- a/hw/watchdog/trace-events
+++ b/hw/watchdog/trace-events
@@ -1,5 +1,12 @@
 # See docs/devel/tracing.rst for syntax documentation.
 
+# allwinner-wdt.c
+allwinner_wdt_read(uint64_t offset, uint64_t data, unsigned size) "Allwinner watchdog read: offset 0x%" PRIx64 " data 0x%" PRIx64 " size %u"
+allwinner_wdt_write(uint64_t offset, uint64_t data, unsigned size) "Allwinner watchdog write: offset 0x%" PRIx64 " data 0x%" PRIx64 " size %u"
+allwinner_wdt_reset_enter(void) "Allwinner watchdog: reset"
+allwinner_wdt_update_timer(uint8_t count) "Allwinner watchdog: count %" PRIu8
+allwinner_wdt_expired(bool enabled, bool reset_enabled) "Allwinner watchdog: enabled %u reset_enabled %u"
+
 # cmsdk-apb-watchdog.c
 cmsdk_apb_watchdog_read(uint64_t offset, uint64_t data, unsigned size) "CMSDK APB watchdog read: offset 0x%" PRIx64 " data 0x%" PRIx64 " size %u"
 cmsdk_apb_watchdog_write(uint64_t offset, uint64_t data, unsigned size) "CMSDK APB watchdog write: offset 0x%" PRIx64 " data 0x%" PRIx64 " size %u"
diff --git a/include/hw/watchdog/allwinner-wdt.h b/include/hw/watchdog/allwinner-wdt.h
new file mode 100644
index 0000000000..7fe41e20f2
--- /dev/null
+++ b/include/hw/watchdog/allwinner-wdt.h
@@ -0,0 +1,123 @@
+/*
+ * 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/>.
+ */
+
+#ifndef HW_WATCHDOG_ALLWINNER_WDT_H
+#define HW_WATCHDOG_ALLWINNER_WDT_H
+
+#include "qom/object.h"
+#include "hw/ptimer.h"
+#include "hw/sysbus.h"
+
+/*
+ * This is a model of the Allwinner watchdog.
+ * Since watchdog registers belong to the timer module (and are shared with the
+ * RTC module), the interrupt line from watchdog is not handled right now.
+ * In QEMU, we just wire up the watchdog reset to watchdog_perform_action(),
+ * at least for the moment.
+ */
+
+#define TYPE_AW_WDT    "allwinner-wdt"
+
+/** Allwinner WDT sun4i family (A10, A12), also sun7i (A20) */
+#define TYPE_AW_WDT_SUN4I    TYPE_AW_WDT "-sun4i"
+
+/** Allwinner WDT sun6i family and newer (A31, H2+, H3, etc) */
+#define TYPE_AW_WDT_SUN6I    TYPE_AW_WDT "-sun6i"
+
+/** Number of WDT registers */
+#define AW_WDT_REGS_NUM      (5)
+
+OBJECT_DECLARE_TYPE(AwWdtState, AwWdtClass, AW_WDT)
+
+/**
+ * Allwinner WDT object instance state.
+ */
+struct AwWdtState {
+    /*< private >*/
+    SysBusDevice parent_obj;
+
+    /*< public >*/
+    MemoryRegion iomem;
+    struct ptimer_state *timer;
+
+    uint32_t regs[AW_WDT_REGS_NUM];
+};
+
+/**
+ * Allwinner WDT class-level struct.
+ *
+ * This struct is filled by each sunxi device specific code
+ * such that the generic code can use this struct to support
+ * all devices.
+ */
+struct AwWdtClass {
+    /*< private >*/
+    SysBusDeviceClass parent_class;
+    /*< public >*/
+
+    /** Defines device specific register map */
+    const uint8_t *regmap;
+
+    /** Size of the regmap in bytes */
+    size_t regmap_size;
+
+    /**
+     * Read device specific register
+     *
+     * @offset: register offset to read
+     * @return true if register read successful, false otherwise
+     */
+    bool (*read)(AwWdtState *s, uint32_t offset);
+
+    /**
+     * Write device specific register
+     *
+     * @offset: register offset to write
+     * @data: value to set in register
+     * @return true if register write successful, false otherwise
+     */
+    bool (*write)(AwWdtState *s, uint32_t offset, uint32_t data);
+
+    /**
+     * Check if watchdog can generate system reset
+     *
+     * @return true if watchdog can generate system reset
+     */
+    bool (*can_reset_system)(AwWdtState *s);
+
+    /**
+     * Check if provided key is valid
+     *
+     * @value: value written to register
+     * @return true if key is valid, false otherwise
+     */
+    bool (*is_key_valid)(AwWdtState *s, uint32_t val);
+
+    /**
+     * Get current INTV_VALUE setting
+     *
+     * @return current INTV_VALUE (0-15)
+     */
+    uint8_t (*get_intv_value)(AwWdtState *s);
+};
+
+#endif /* HW_WATCHDOG_ALLWINNER_WDT_H */