/*- * Copyright (c) 2012 Damjan Marion * All rights reserved. * * 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 __FBSDID("$FreeBSD$"); #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include "am335x_dmtreg.h" struct am335x_dmtimer_softc { device_t dev; int tmr_mem_rid; struct resource * tmr_mem_res; int tmr_irq_rid; struct resource * tmr_irq_res; void *tmr_irq_handler; uint32_t sysclk_freq; uint32_t tclr; /* Cached TCLR register. */ union { struct timecounter tc; struct eventtimer et; } func; int tmr_num; /* Hardware unit number. */ char tmr_name[12]; /* "DMTimerN", N = tmr_num */ }; static struct am335x_dmtimer_softc *am335x_dmtimer_et_sc = NULL; static struct am335x_dmtimer_softc *am335x_dmtimer_tc_sc = NULL; /* * We use dmtimer2 for eventtimer and dmtimer3 for timecounter. */ #define ET_TMR_NUM 2 #define TC_TMR_NUM 3 /* List of compatible strings for FDT tree */ static struct ofw_compat_data compat_data[] = { {"ti,am335x-timer", 1}, {"ti,am335x-timer-1ms", 1}, {NULL, 0}, }; #define DMTIMER_READ4(sc, reg) bus_read_4((sc)->tmr_mem_res, (reg)) #define DMTIMER_WRITE4(sc, reg, val) bus_write_4((sc)->tmr_mem_res, (reg), (val)) static int am335x_dmtimer_et_start(struct eventtimer *et, sbintime_t first, sbintime_t period) { struct am335x_dmtimer_softc *sc; uint32_t initial_count, reload_count; sc = et->et_priv; /* * Stop the timer before changing it. This routine will often be called * while the timer is still running, to either lengthen or shorten the * current event time. We need to ensure the timer doesn't expire while * we're working with it. * * Also clear any pending interrupt status, because it's at least * theoretically possible that we're running in a primary interrupt * context now, and a timer interrupt could be pending even before we * stopped the timer. The more likely case is that we're being called * from the et_event_cb() routine dispatched from our own handler, but * it's not clear to me that that's the only case possible. */ sc->tclr &= ~(DMT_TCLR_START | DMT_TCLR_AUTOLOAD); DMTIMER_WRITE4(sc, DMT_TCLR, sc->tclr); DMTIMER_WRITE4(sc, DMT_IRQSTATUS, DMT_IRQ_OVF); if (period != 0) { reload_count = ((uint32_t)et->et_frequency * period) >> 32; sc->tclr |= DMT_TCLR_AUTOLOAD; } else { reload_count = 0; } if (first != 0) initial_count = ((uint32_t)et->et_frequency * first) >> 32; else initial_count = reload_count; /* * Set auto-reload and current-count values. This timer hardware counts * up from the initial/reload value and interrupts on the zero rollover. */ DMTIMER_WRITE4(sc, DMT_TLDR, 0xFFFFFFFF - reload_count); DMTIMER_WRITE4(sc, DMT_TCRR, 0xFFFFFFFF - initial_count); /* Enable overflow interrupt, and start the timer. */ DMTIMER_WRITE4(sc, DMT_IRQENABLE_SET, DMT_IRQ_OVF); sc->tclr |= DMT_TCLR_START; DMTIMER_WRITE4(sc, DMT_TCLR, sc->tclr); return (0); } static int am335x_dmtimer_et_stop(struct eventtimer *et) { struct am335x_dmtimer_softc *sc; sc = et->et_priv; /* Stop timer, disable and clear interrupt. */ sc->tclr &= ~(DMT_TCLR_START | DMT_TCLR_AUTOLOAD); DMTIMER_WRITE4(sc, DMT_TCLR, sc->tclr); DMTIMER_WRITE4(sc, DMT_IRQENABLE_CLR, DMT_IRQ_OVF); DMTIMER_WRITE4(sc, DMT_IRQSTATUS, DMT_IRQ_OVF); return (0); } static int am335x_dmtimer_et_intr(void *arg) { struct am335x_dmtimer_softc *sc; sc = arg; /* Ack the interrupt, and invoke the callback if it's still enabled. */ DMTIMER_WRITE4(sc, DMT_IRQSTATUS, DMT_IRQ_OVF); if (sc->func.et.et_active) sc->func.et.et_event_cb(&sc->func.et, sc->func.et.et_arg); return (FILTER_HANDLED); } static int am335x_dmtimer_et_init(struct am335x_dmtimer_softc *sc) { KASSERT(am335x_dmtimer_et_sc == NULL, ("already have an eventtimer")); /* * Setup eventtimer interrupt handling. Panic if anything goes wrong, * because the system just isn't going to run without an eventtimer. */ sc->tmr_irq_res = bus_alloc_resource_any(sc->dev, SYS_RES_IRQ, &sc->tmr_irq_rid, RF_ACTIVE); if (sc->tmr_irq_res == NULL) panic("am335x_dmtimer: could not allocate irq resources"); if (bus_setup_intr(sc->dev, sc->tmr_irq_res, INTR_TYPE_CLK, am335x_dmtimer_et_intr, NULL, sc, &sc->tmr_irq_handler) != 0) panic("am335x_dmtimer: count not setup irq handler"); sc->func.et.et_name = sc->tmr_name; sc->func.et.et_flags = ET_FLAGS_PERIODIC | ET_FLAGS_ONESHOT; sc->func.et.et_quality = 500; sc->func.et.et_frequency = sc->sysclk_freq; sc->func.et.et_min_period = ((0x00000005LLU << 32) / sc->func.et.et_frequency); sc->func.et.et_max_period = (0xfffffffeLLU << 32) / sc->func.et.et_frequency; sc->func.et.et_start = am335x_dmtimer_et_start; sc->func.et.et_stop = am335x_dmtimer_et_stop; sc->func.et.et_priv = sc; am335x_dmtimer_et_sc = sc; et_register(&sc->func.et); return (0); } static unsigned am335x_dmtimer_tc_get_timecount(struct timecounter *tc) { struct am335x_dmtimer_softc *sc; sc = tc->tc_priv; return (DMTIMER_READ4(sc, DMT_TCRR)); } static int am335x_dmtimer_tc_init(struct am335x_dmtimer_softc *sc) { KASSERT(am335x_dmtimer_tc_sc == NULL, ("already have a timecounter")); /* Set up timecounter, start it, register it. */ DMTIMER_WRITE4(sc, DMT_TSICR, DMT_TSICR_RESET); while (DMTIMER_READ4(sc, DMT_TIOCP_CFG) & DMT_TIOCP_RESET) continue; sc->tclr |= DMT_TCLR_START | DMT_TCLR_AUTOLOAD; DMTIMER_WRITE4(sc, DMT_TLDR, 0); DMTIMER_WRITE4(sc, DMT_TCRR, 0); DMTIMER_WRITE4(sc, DMT_TCLR, sc->tclr); sc->func.tc.tc_name = sc->tmr_name; sc->func.tc.tc_get_timecount = am335x_dmtimer_tc_get_timecount; sc->func.tc.tc_counter_mask = ~0u; sc->func.tc.tc_frequency = sc->sysclk_freq; sc->func.tc.tc_quality = 500; sc->func.tc.tc_priv = sc; am335x_dmtimer_tc_sc = sc; tc_init(&sc->func.tc); return (0); } static int am335x_dmtimer_probe(device_t dev) { char strbuf[32]; int tmr_num; if (!ofw_bus_status_okay(dev)) return (ENXIO); if (ofw_bus_search_compatible(dev, compat_data)->ocd_data == 0) return (ENXIO); /* * Get the hardware unit number (the N from ti,hwmods="timerN"). * If this isn't the hardware unit we're going to use for either the * eventtimer or the timecounter, no point in instantiating the device. */ tmr_num = ti_hwmods_get_unit(dev, "timer"); if (tmr_num != ET_TMR_NUM && tmr_num != TC_TMR_NUM) return (ENXIO); snprintf(strbuf, sizeof(strbuf), "AM335x DMTimer%d", tmr_num); device_set_desc_copy(dev, strbuf); return(BUS_PROBE_DEFAULT); } static int am335x_dmtimer_attach(device_t dev) { struct am335x_dmtimer_softc *sc; clk_ident_t timer_id; int err; sc = device_get_softc(dev); sc->dev = dev; /* Get the base clock frequency. */ if ((err = ti_prcm_clk_get_source_freq(SYS_CLK, &sc->sysclk_freq)) != 0) return (err); /* Enable clocks and power on the device. */ if ((timer_id = ti_hwmods_get_clock(dev)) == INVALID_CLK_IDENT) return (ENXIO); if ((err = ti_prcm_clk_set_source(timer_id, SYSCLK_CLK)) != 0) return (err); if ((err = ti_prcm_clk_enable(timer_id)) != 0) return (err); /* Request the memory resources. */ sc->tmr_mem_res = bus_alloc_resource_any(dev, SYS_RES_MEMORY, &sc->tmr_mem_rid, RF_ACTIVE); if (sc->tmr_mem_res == NULL) { return (ENXIO); } sc->tmr_num = ti_hwmods_get_unit(dev, "timer"); snprintf(sc->tmr_name, sizeof(sc->tmr_name), "DMTimer%d", sc->tmr_num); /* * Go set up either a timecounter or eventtimer. We wouldn't have * attached if we weren't one or the other. */ if (sc->tmr_num == ET_TMR_NUM) am335x_dmtimer_et_init(sc); else if (sc->tmr_num == TC_TMR_NUM) am335x_dmtimer_tc_init(sc); else panic("am335x_dmtimer: bad timer number %d", sc->tmr_num); return (0); } static device_method_t am335x_dmtimer_methods[] = { DEVMETHOD(device_probe, am335x_dmtimer_probe), DEVMETHOD(device_attach, am335x_dmtimer_attach), { 0, 0 } }; static driver_t am335x_dmtimer_driver = { "am335x_dmtimer", am335x_dmtimer_methods, sizeof(struct am335x_dmtimer_softc), }; static devclass_t am335x_dmtimer_devclass; DRIVER_MODULE(am335x_dmtimer, simplebus, am335x_dmtimer_driver, am335x_dmtimer_devclass, 0, 0); MODULE_DEPEND(am335x_dmtimer, am335x_prcm, 1, 1, 1); void DELAY(int usec) { struct am335x_dmtimer_softc *sc; int32_t counts; uint32_t first, last; sc = am335x_dmtimer_tc_sc; if (sc == NULL) { for (; usec > 0; usec--) for (counts = 200; counts > 0; counts--) /* Prevent gcc from optimizing out the loop */ cpufunc_nullop(); return; } /* Get the number of times to count */ counts = (usec + 1) * (sc->sysclk_freq / 1000000); first = DMTIMER_READ4(sc, DMT_TCRR); while (counts > 0) { last = DMTIMER_READ4(sc, DMT_TCRR); if (last > first) { counts -= (int32_t)(last - first); } else { counts -= (int32_t)((0xFFFFFFFF - first) + last); } first = last; } }