Index: sys/dev/dwwdt/dwwdt.c =================================================================== --- sys/dev/dwwdt/dwwdt.c +++ sys/dev/dwwdt/dwwdt.c @@ -0,0 +1,360 @@ +/*- + * SPDX-License-Identifier: BSD-2-Clause-FreeBSD + * + * Copyright (c) 2020 BusyTech + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * 1. Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * 2. Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in the + * documentation and/or other materials provided with the distribution. + * + * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND + * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE + * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE + * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE + * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL + * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS + * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) + * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT + * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY + * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF + * SUCH DAMAGE. + */ + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#include +#include + +#include +#include +#include +#include +#include + +/* Registers */ +#define DWWDT_CR 0x00 +#define DWWDT_CR_WDT_EN (1 << 0) +#define DWWDT_CR_RESP_MODE (1 << 1) +#define DWWDT_TORR 0x04 +#define DWWDT_CCVR 0x08 +#define DWWDT_CRR 0x0C +#define DWWDT_CRR_KICK 0x76 +#define DWWDT_STAT 0x10 +#define DWWDT_STAT_STATUS 0x01 +#define DWWDT_EOI 0x14 + +#define DWWDT_READ4(sc, reg) bus_read_4((sc)->sc_mem_res, (reg)) +#define DWWDT_WRITE4(sc, reg, val) \ + bus_write_4((sc)->sc_mem_res, (reg), (val)) + +/* + * 45 = 16 (timeout shift of dwwdt) + 30 (1s ~= 2 ** 30ns) - 1 + * pre-restart delay) + */ +#define DWWDT_EXP_OFFSET 45 + +struct dwwdt_softc { + device_t sc_dev; + struct resource *sc_mem_res; + struct resource *sc_irq_res; + void *sc_intr_cookie; + clk_t sc_clk; + uint64_t sc_clk_freq; + eventhandler_tag sc_evtag; + int sc_mem_rid; + int sc_irq_rid; + enum { + DWWDT_STOPPED, + DWWDT_RUNNING, + } sc_status; +}; + +static devclass_t dwwdt_devclass; + +SYSCTL_NODE(_dev, OID_AUTO, dwwdt, CTLFLAG_RW | CTLFLAG_MPSAFE, 0, + "Synopsys Designware watchdog timer"); +/* Setting this to 0 enables full restart mode. */ +static uint32_t dwwdt_prevent_restart = 1; +SYSCTL_UINT(_dev_dwwdt, OID_AUTO, prevent_restart, CTLFLAG_RW | CTLFLAG_MPSAFE, + &dwwdt_prevent_restart, 1, + "Prevent system restart (0 - Disabled; 1 - Enabled)"); + +static uint32_t dwwdt_debug_enabled = 0; +SYSCTL_UINT(_dev_dwwdt, OID_AUTO, debug, CTLFLAG_RW | CTLFLAG_MPSAFE, + &dwwdt_debug_enabled, 1, "Debug mode (0 - Disabled; 1 - Enabled)"); + +static int dwwdt_probe(device_t); +static int dwwdt_attach(device_t); +static int dwwdt_detach(device_t); +static int dwwdt_shutdown(device_t); + +static void dwwdt_intr(void *); +static void dwwdt_event(void *, unsigned int, int *); + +/* Helpers */ +static inline void dwwdt_start(struct dwwdt_softc *sc); +static inline bool dwwdt_started(const struct dwwdt_softc *sc); +static inline void dwwdt_stop(struct dwwdt_softc *sc); +static inline void dwwdt_set_timeout(const struct dwwdt_softc *sc, int val); + +static void dwwdt_debug(device_t); + +static void +dwwdt_debug(device_t dev) +{ + /* + * Reading from EOI may clear interrupt flag. + */ + const struct dwwdt_softc *sc = device_get_softc(dev); + + device_printf(dev, "Registers dump: \n"); + device_printf(dev, " CR: %08x\n", DWWDT_READ4(sc, DWWDT_CR)); + device_printf(dev, " CCVR: %08x\n", DWWDT_READ4(sc, DWWDT_CCVR)); + device_printf(dev, " CRR: %08x\n", DWWDT_READ4(sc, DWWDT_CRR)); + device_printf(dev, " STAT: %08x\n", DWWDT_READ4(sc, DWWDT_STAT)); + + device_printf(dev, "Clock: %s\n", clk_get_name(sc->sc_clk)); + device_printf(dev, " FREQ: %lu\n", sc->sc_clk_freq); +} + +static inline bool +dwwdt_started(const struct dwwdt_softc *sc) +{ + + /* CR_WDT_E bit can be clear only by full CPU reset. */ + return ((DWWDT_READ4(sc, DWWDT_CR) & DWWDT_CR_WDT_EN) != 0); +} + +static void inline +dwwdt_start(struct dwwdt_softc *sc) +{ + uint32_t val; + + /* Enable watchdog */ + val = DWWDT_READ4(sc, DWWDT_CR); + val |= DWWDT_CR_WDT_EN | DWWDT_CR_RESP_MODE; + DWWDT_WRITE4(sc, DWWDT_CR, val); + sc->sc_status = DWWDT_RUNNING; +} + +static void inline +dwwdt_stop(struct dwwdt_softc *sc) +{ + + sc->sc_status = DWWDT_STOPPED; + dwwdt_set_timeout(sc, 0x0f); +} + +static void inline +dwwdt_set_timeout(const struct dwwdt_softc *sc, int val) +{ + + DWWDT_WRITE4(sc, DWWDT_TORR, val); + DWWDT_WRITE4(sc, DWWDT_CRR, DWWDT_CRR_KICK); +} + +static void +dwwdt_intr(void *arg) +{ + struct dwwdt_softc *sc = arg; + + KASSERT((DWWDT_READ4(sc, DWWDT_STAT) & DWWDT_STAT_STATUS) != 0, + ("Missing interrupt status bit?")); + + if (dwwdt_prevent_restart != 0 || sc->sc_status == DWWDT_STOPPED) { + /* + * Confirm interrupt reception. Restart counter. + * This also emulates stopping watchdog. + */ + (void)DWWDT_READ4(sc, DWWDT_EOI); + } +} + +static void +dwwdt_event(void *arg, unsigned int cmd, int *error) +{ + struct dwwdt_softc *sc = arg; + const int exponent = flsl(sc->sc_clk_freq); + int timeout; + int val; + + dwwdt_stop(sc); + timeout = cmd & WD_INTERVAL; + val = MAX(0, timeout + exponent - DWWDT_EXP_OFFSET); + + if (cmd == 0 || val > 0x0f) { + /* + * Set maximum time between interrupts and Leave watchdog + * disabled. + */ + return; + } + + dwwdt_set_timeout(sc, val); + dwwdt_start(sc); + *error = 0; + + if (dwwdt_debug_enabled) + dwwdt_debug(sc->sc_dev); +} + +static int +dwwdt_probe(device_t dev) +{ + if (!ofw_bus_status_okay(dev)) + return (ENXIO); + + if (!ofw_bus_is_compatible(dev, "snps,dw-wdt")) + return (ENXIO); + + device_set_desc(dev, "Synopsys Designware watchdog timer"); + return (BUS_PROBE_DEFAULT); +} + +static int +dwwdt_attach(device_t dev) +{ + struct dwwdt_softc *sc; + + sc = device_get_softc(dev); + sc->sc_dev = dev; + + sc->sc_mem_rid = 0; + sc->sc_mem_res = bus_alloc_resource_any(dev, SYS_RES_MEMORY, + &sc->sc_mem_rid, RF_ACTIVE); + if (sc->sc_mem_res == NULL) { + device_printf(dev, "cannot allocate memory resource\n"); + goto err_no_mem; + } + + sc->sc_irq_rid = 0; + sc->sc_irq_res = bus_alloc_resource_any(dev, SYS_RES_IRQ, + &sc->sc_irq_rid, RF_ACTIVE); + if (sc->sc_irq_res == NULL) { + device_printf(dev, "cannot allocate ireq resource\n"); + goto err_no_irq; + } + + sc->sc_intr_cookie = NULL; + if (bus_setup_intr(dev, sc->sc_irq_res, INTR_MPSAFE | INTR_TYPE_MISC, + NULL, dwwdt_intr, sc, &sc->sc_intr_cookie) != 0) { + device_printf(dev, "cannot setup interrupt routine\n"); + goto err_no_intr; + } + + if (clk_get_by_ofw_index(dev, 0, 0, &sc->sc_clk) != 0) { + device_printf(dev, "cannot find clock\n"); + goto err_no_clock; + } + + if (clk_enable(sc->sc_clk) != 0) { + device_printf(dev, "cannot enable clock\n"); + goto err_no_freq; + } + + if (clk_get_freq(sc->sc_clk, &sc->sc_clk_freq) != 0) { + device_printf(dev, "cannot get clock frequency\n"); + goto err_no_freq; + } + + if (sc->sc_clk_freq == 0UL) + goto err_no_freq; + + sc->sc_evtag = EVENTHANDLER_REGISTER(watchdog_list, dwwdt_event, sc, 0); + sc->sc_status = DWWDT_STOPPED; + + return (bus_generic_attach(dev)); + +err_no_freq: + clk_release(sc->sc_clk); +err_no_clock: + bus_teardown_intr(dev, sc->sc_irq_res, sc->sc_intr_cookie); +err_no_intr: + bus_release_resource(dev, SYS_RES_IRQ, sc->sc_irq_rid, sc->sc_irq_res); +err_no_irq: + bus_release_resource(dev, SYS_RES_MEMORY, sc->sc_mem_rid, + sc->sc_mem_res); +err_no_mem: + return (ENXIO); +} + +static int +dwwdt_detach(device_t dev) +{ + struct dwwdt_softc *sc = device_get_softc(dev); + + if (dwwdt_started(sc)) { + /* + * Once started it cannot be stopped. Prevent module unload + * instead. + */ + return (EBUSY); + } + + EVENTHANDLER_DEREGISTER(watchdog_list, sc->sc_evtag); + sc->sc_evtag = NULL; + + if (sc->sc_clk != NULL) + clk_release(sc->sc_clk); + + if (sc->sc_intr_cookie != NULL) + bus_teardown_intr(dev, sc->sc_irq_res, sc->sc_intr_cookie); + + if (sc->sc_irq_res) { + bus_release_resource(dev, SYS_RES_IRQ, sc->sc_irq_rid, + sc->sc_irq_res); + } + + if (sc->sc_mem_res) { + bus_release_resource(dev, SYS_RES_MEMORY, sc->sc_mem_rid, + sc->sc_mem_res); + } + + return (bus_generic_detach(dev)); +} + +static int +dwwdt_shutdown(device_t dev) +{ + struct dwwdt_softc *sc; + + sc = device_get_softc(dev); + + /* Prevent restarts during shutdown. */ + dwwdt_prevent_restart = 1; + dwwdt_stop(sc); + return (bus_generic_shutdown(dev)); +} + +static device_method_t dwwdt_methods[] = { + DEVMETHOD(device_probe, dwwdt_probe), + DEVMETHOD(device_attach, dwwdt_attach), + DEVMETHOD(device_detach, dwwdt_detach), + DEVMETHOD(device_shutdown, dwwdt_shutdown), + + {0, 0} +}; + +static driver_t dwwdt_driver = { + "dwwdt", + dwwdt_methods, + sizeof(struct dwwdt_softc), +}; + +DRIVER_MODULE(dwwdt, simplebus, dwwdt_driver, dwwdt_devclass, NULL, NULL); +MODULE_VERSION(dwwdt, 1); Index: sys/modules/Makefile =================================================================== --- sys/modules/Makefile +++ sys/modules/Makefile @@ -107,6 +107,7 @@ dcons_crom \ ${_dpms} \ dummynet \ + ${_dwwdt} \ ${_efirt} \ ${_em} \ ${_ena} \ @@ -601,6 +602,7 @@ .if ${MACHINE_CPUARCH} == "aarch64" _allwinner= allwinner _armv8crypto= armv8crypto +_dwwdt= dwwdt _em= em _rockchip= rockchip .endif Index: sys/modules/dwwdt/Makefile =================================================================== --- sys/modules/dwwdt/Makefile +++ sys/modules/dwwdt/Makefile @@ -0,0 +1,7 @@ +.PATH: ${SRCTOP}/sys/dev/dwwdt + +KMOD = dwwdt +SRCS = dwwdt.c \ + device_if.h bus_if.h ofw_bus_if.h + +.include