From daca13d495a11945c22d2aa68ad28dc5c8180911 Mon Sep 17 00:00:00 2001 From: Guenter Roeck Date: Sun, 17 May 2020 09:21:29 -0700 Subject: [PATCH] hw/watchdog: Implement full i.MX watchdog support Implement full support for the watchdog in i.MX systems. Pretimeout support is optional because the watchdog hardware on i.MX31 does not support pretimeouts. Signed-off-by: Guenter Roeck Message-id: 20200517162135.110364-3-linux@roeck-us.net Signed-off-by: Peter Maydell [PMM: added Property array terminator entry] Reviewed-by: Peter Maydell --- hw/watchdog/wdt_imx2.c | 240 +++++++++++++++++++++++++++++++-- include/hw/watchdog/wdt_imx2.h | 61 ++++++++- 2 files changed, 286 insertions(+), 15 deletions(-) diff --git a/hw/watchdog/wdt_imx2.c b/hw/watchdog/wdt_imx2.c index ad1ef02e9e..a5fb76308f 100644 --- a/hw/watchdog/wdt_imx2.c +++ b/hw/watchdog/wdt_imx2.c @@ -13,24 +13,189 @@ #include "qemu/bitops.h" #include "qemu/module.h" #include "sysemu/watchdog.h" +#include "migration/vmstate.h" +#include "hw/qdev-properties.h" #include "hw/watchdog/wdt_imx2.h" -#define IMX2_WDT_WCR_WDA BIT(5) /* -> External Reset WDOG_B */ -#define IMX2_WDT_WCR_SRS BIT(4) /* -> Software Reset Signal */ - -static uint64_t imx2_wdt_read(void *opaque, hwaddr addr, - unsigned int size) +static void imx2_wdt_interrupt(void *opaque) { + IMX2WdtState *s = IMX2_WDT(opaque); + + s->wicr |= IMX2_WDT_WICR_WTIS; + qemu_set_irq(s->irq, 1); +} + +static void imx2_wdt_expired(void *opaque) +{ + IMX2WdtState *s = IMX2_WDT(opaque); + + s->wrsr = IMX2_WDT_WRSR_TOUT; + + /* Perform watchdog action if watchdog is enabled */ + if (s->wcr & IMX2_WDT_WCR_WDE) { + s->wrsr = IMX2_WDT_WRSR_TOUT; + watchdog_perform_action(); + } +} + +static void imx2_wdt_reset(DeviceState *dev) +{ + IMX2WdtState *s = IMX2_WDT(dev); + + ptimer_transaction_begin(s->timer); + ptimer_stop(s->timer); + ptimer_transaction_commit(s->timer); + + if (s->pretimeout_support) { + ptimer_transaction_begin(s->itimer); + ptimer_stop(s->itimer); + ptimer_transaction_commit(s->itimer); + } + + s->wicr_locked = false; + s->wcr_locked = false; + s->wcr_wde_locked = false; + + s->wcr = IMX2_WDT_WCR_WDA | IMX2_WDT_WCR_SRS; + s->wsr = 0; + s->wrsr &= ~(IMX2_WDT_WRSR_TOUT | IMX2_WDT_WRSR_SFTW); + s->wicr = IMX2_WDT_WICR_WICT_DEF; + s->wmcr = IMX2_WDT_WMCR_PDE; +} + +static uint64_t imx2_wdt_read(void *opaque, hwaddr addr, unsigned int size) +{ + IMX2WdtState *s = IMX2_WDT(opaque); + + switch (addr) { + case IMX2_WDT_WCR: + return s->wcr; + case IMX2_WDT_WSR: + return s->wsr; + case IMX2_WDT_WRSR: + return s->wrsr; + case IMX2_WDT_WICR: + return s->wicr; + case IMX2_WDT_WMCR: + return s->wmcr; + } return 0; } +static void imx_wdt2_update_itimer(IMX2WdtState *s, bool start) +{ + bool running = (s->wcr & IMX2_WDT_WCR_WDE) && (s->wcr & IMX2_WDT_WCR_WT); + bool enabled = s->wicr & IMX2_WDT_WICR_WIE; + + ptimer_transaction_begin(s->itimer); + if (start || !enabled) { + ptimer_stop(s->itimer); + } + if (running && enabled) { + int count = ptimer_get_count(s->timer); + int pretimeout = s->wicr & IMX2_WDT_WICR_WICT; + + /* + * Only (re-)start pretimeout timer if its counter value is larger + * than 0. Otherwise it will fire right away and we'll get an + * interrupt loop. + */ + if (count > pretimeout) { + ptimer_set_count(s->itimer, count - pretimeout); + if (start) { + ptimer_run(s->itimer, 1); + } + } + } + ptimer_transaction_commit(s->itimer); +} + +static void imx_wdt2_update_timer(IMX2WdtState *s, bool start) +{ + ptimer_transaction_begin(s->timer); + if (start) { + ptimer_stop(s->timer); + } + if ((s->wcr & IMX2_WDT_WCR_WDE) && (s->wcr & IMX2_WDT_WCR_WT)) { + int count = (s->wcr & IMX2_WDT_WCR_WT) >> 8; + + /* A value of 0 reflects one period (0.5s). */ + ptimer_set_count(s->timer, count + 1); + if (start) { + ptimer_run(s->timer, 1); + } + } + ptimer_transaction_commit(s->timer); + if (s->pretimeout_support) { + imx_wdt2_update_itimer(s, start); + } +} + static void imx2_wdt_write(void *opaque, hwaddr addr, uint64_t value, unsigned int size) { - if (addr == IMX2_WDT_WCR && - (~value & (IMX2_WDT_WCR_WDA | IMX2_WDT_WCR_SRS))) { - watchdog_perform_action(); + IMX2WdtState *s = IMX2_WDT(opaque); + + switch (addr) { + case IMX2_WDT_WCR: + if (s->wcr_locked) { + value &= ~IMX2_WDT_WCR_LOCK_MASK; + value |= (s->wicr & IMX2_WDT_WCR_LOCK_MASK); + } + s->wcr_locked = true; + if (s->wcr_wde_locked) { + value &= ~IMX2_WDT_WCR_WDE; + value |= (s->wicr & ~IMX2_WDT_WCR_WDE); + } else if (value & IMX2_WDT_WCR_WDE) { + s->wcr_wde_locked = true; + } + if (s->wcr_wdt_locked) { + value &= ~IMX2_WDT_WCR_WDT; + value |= (s->wicr & ~IMX2_WDT_WCR_WDT); + } else if (value & IMX2_WDT_WCR_WDT) { + s->wcr_wdt_locked = true; + } + + s->wcr = value; + if (!(value & IMX2_WDT_WCR_SRS)) { + s->wrsr = IMX2_WDT_WRSR_SFTW; + } + if (!(value & (IMX2_WDT_WCR_WDA | IMX2_WDT_WCR_SRS)) || + (!(value & IMX2_WDT_WCR_WT) && (value & IMX2_WDT_WCR_WDE))) { + watchdog_perform_action(); + } + s->wcr |= IMX2_WDT_WCR_SRS; + imx_wdt2_update_timer(s, true); + break; + case IMX2_WDT_WSR: + if (s->wsr == IMX2_WDT_SEQ1 && value == IMX2_WDT_SEQ2) { + imx_wdt2_update_timer(s, false); + } + s->wsr = value; + break; + case IMX2_WDT_WRSR: + break; + case IMX2_WDT_WICR: + if (!s->pretimeout_support) { + return; + } + value &= IMX2_WDT_WICR_LOCK_MASK | IMX2_WDT_WICR_WTIS; + if (s->wicr_locked) { + value &= IMX2_WDT_WICR_WTIS; + value |= (s->wicr & IMX2_WDT_WICR_LOCK_MASK); + } + s->wicr = value | (s->wicr & IMX2_WDT_WICR_WTIS); + if (value & IMX2_WDT_WICR_WTIS) { + s->wicr &= ~IMX2_WDT_WICR_WTIS; + qemu_set_irq(s->irq, 0); + } + imx_wdt2_update_itimer(s, true); + s->wicr_locked = true; + break; + case IMX2_WDT_WMCR: + s->wmcr = value & IMX2_WDT_WMCR_PDE; + break; } } @@ -45,28 +210,77 @@ static const MemoryRegionOps imx2_wdt_ops = { * real device but in practice there is no reason for a guest * to access this device unaligned. */ - .min_access_size = 4, - .max_access_size = 4, + .min_access_size = 2, + .max_access_size = 2, .unaligned = false, }, }; +static const VMStateDescription vmstate_imx2_wdt = { + .name = "imx2.wdt", + .fields = (VMStateField[]) { + VMSTATE_PTIMER(timer, IMX2WdtState), + VMSTATE_PTIMER(itimer, IMX2WdtState), + VMSTATE_BOOL(wicr_locked, IMX2WdtState), + VMSTATE_BOOL(wcr_locked, IMX2WdtState), + VMSTATE_BOOL(wcr_wde_locked, IMX2WdtState), + VMSTATE_BOOL(wcr_wdt_locked, IMX2WdtState), + VMSTATE_UINT16(wcr, IMX2WdtState), + VMSTATE_UINT16(wsr, IMX2WdtState), + VMSTATE_UINT16(wrsr, IMX2WdtState), + VMSTATE_UINT16(wmcr, IMX2WdtState), + VMSTATE_UINT16(wicr, IMX2WdtState), + VMSTATE_END_OF_LIST() + } +}; + static void imx2_wdt_realize(DeviceState *dev, Error **errp) { IMX2WdtState *s = IMX2_WDT(dev); + SysBusDevice *sbd = SYS_BUS_DEVICE(dev); memory_region_init_io(&s->mmio, OBJECT(dev), &imx2_wdt_ops, s, - TYPE_IMX2_WDT".mmio", - IMX2_WDT_REG_NUM * sizeof(uint16_t)); - sysbus_init_mmio(SYS_BUS_DEVICE(dev), &s->mmio); + TYPE_IMX2_WDT, + IMX2_WDT_MMIO_SIZE); + sysbus_init_mmio(sbd, &s->mmio); + sysbus_init_irq(sbd, &s->irq); + + s->timer = ptimer_init(imx2_wdt_expired, s, + PTIMER_POLICY_NO_IMMEDIATE_TRIGGER | + PTIMER_POLICY_NO_IMMEDIATE_RELOAD | + PTIMER_POLICY_NO_COUNTER_ROUND_DOWN); + ptimer_transaction_begin(s->timer); + ptimer_set_freq(s->timer, 2); + ptimer_set_limit(s->timer, 0xff, 1); + ptimer_transaction_commit(s->timer); + if (s->pretimeout_support) { + s->itimer = ptimer_init(imx2_wdt_interrupt, s, + PTIMER_POLICY_NO_IMMEDIATE_TRIGGER | + PTIMER_POLICY_NO_IMMEDIATE_RELOAD | + PTIMER_POLICY_NO_COUNTER_ROUND_DOWN); + ptimer_transaction_begin(s->itimer); + ptimer_set_freq(s->itimer, 2); + ptimer_set_limit(s->itimer, 0xff, 1); + ptimer_transaction_commit(s->itimer); + } } +static Property imx2_wdt_properties[] = { + DEFINE_PROP_BOOL("pretimeout-support", IMX2WdtState, pretimeout_support, + false), + DEFINE_PROP_END_OF_LIST() +}; + static void imx2_wdt_class_init(ObjectClass *klass, void *data) { DeviceClass *dc = DEVICE_CLASS(klass); + device_class_set_props(dc, imx2_wdt_properties); dc->realize = imx2_wdt_realize; + dc->reset = imx2_wdt_reset; + dc->vmsd = &vmstate_imx2_wdt; + dc->desc = "i.MX watchdog timer"; set_bit(DEVICE_CATEGORY_MISC, dc->categories); } diff --git a/include/hw/watchdog/wdt_imx2.h b/include/hw/watchdog/wdt_imx2.h index b91b002528..f9af6be4b6 100644 --- a/include/hw/watchdog/wdt_imx2.h +++ b/include/hw/watchdog/wdt_imx2.h @@ -12,22 +12,79 @@ #ifndef IMX2_WDT_H #define IMX2_WDT_H +#include "qemu/bitops.h" #include "hw/sysbus.h" +#include "hw/irq.h" +#include "hw/ptimer.h" #define TYPE_IMX2_WDT "imx2.wdt" #define IMX2_WDT(obj) OBJECT_CHECK(IMX2WdtState, (obj), TYPE_IMX2_WDT) enum IMX2WdtRegisters { - IMX2_WDT_WCR = 0x0000, - IMX2_WDT_REG_NUM = 0x0008 / sizeof(uint16_t) + 1, + IMX2_WDT_WCR = 0x0000, /* Control Register */ + IMX2_WDT_WSR = 0x0002, /* Service Register */ + IMX2_WDT_WRSR = 0x0004, /* Reset Status Register */ + IMX2_WDT_WICR = 0x0006, /* Interrupt Control Register */ + IMX2_WDT_WMCR = 0x0008, /* Misc Register */ }; +#define IMX2_WDT_MMIO_SIZE 0x000a + +/* Control Register definitions */ +#define IMX2_WDT_WCR_WT (0xFF << 8) /* Watchdog Timeout Field */ +#define IMX2_WDT_WCR_WDW BIT(7) /* WDOG Disable for Wait */ +#define IMX2_WDT_WCR_WDA BIT(5) /* WDOG Assertion */ +#define IMX2_WDT_WCR_SRS BIT(4) /* Software Reset Signal */ +#define IMX2_WDT_WCR_WDT BIT(3) /* WDOG Timeout Assertion */ +#define IMX2_WDT_WCR_WDE BIT(2) /* Watchdog Enable */ +#define IMX2_WDT_WCR_WDBG BIT(1) /* Watchdog Debug Enable */ +#define IMX2_WDT_WCR_WDZST BIT(0) /* Watchdog Timer Suspend */ + +#define IMX2_WDT_WCR_LOCK_MASK (IMX2_WDT_WCR_WDZST | IMX2_WDT_WCR_WDBG \ + | IMX2_WDT_WCR_WDW) + +/* Service Register definitions */ +#define IMX2_WDT_SEQ1 0x5555 /* service sequence 1 */ +#define IMX2_WDT_SEQ2 0xAAAA /* service sequence 2 */ + +/* Reset Status Register definitions */ +#define IMX2_WDT_WRSR_TOUT BIT(1) /* Reset due to Timeout */ +#define IMX2_WDT_WRSR_SFTW BIT(0) /* Reset due to software reset */ + +/* Interrupt Control Register definitions */ +#define IMX2_WDT_WICR_WIE BIT(15) /* Interrupt Enable */ +#define IMX2_WDT_WICR_WTIS BIT(14) /* Interrupt Status */ +#define IMX2_WDT_WICR_WICT 0xff /* Interrupt Timeout */ +#define IMX2_WDT_WICR_WICT_DEF 0x04 /* Default interrupt timeout (2s) */ + +#define IMX2_WDT_WICR_LOCK_MASK (IMX2_WDT_WICR_WIE | IMX2_WDT_WICR_WICT) + +/* Misc Control Register definitions */ +#define IMX2_WDT_WMCR_PDE BIT(0) /* Power-Down Enable */ typedef struct IMX2WdtState { /* */ SysBusDevice parent_obj; + /*< public >*/ MemoryRegion mmio; + qemu_irq irq; + + struct ptimer_state *timer; + struct ptimer_state *itimer; + + bool pretimeout_support; + bool wicr_locked; + + uint16_t wcr; + uint16_t wsr; + uint16_t wrsr; + uint16_t wicr; + uint16_t wmcr; + + bool wcr_locked; /* affects WDZST, WDBG, and WDW */ + bool wcr_wde_locked; /* affects WDE */ + bool wcr_wdt_locked; /* affects WDT (never cleared) */ } IMX2WdtState; #endif /* IMX2_WDT_H */