/* $OpenBSD: dmtimer.c,v 1.6 2015/01/22 14:33:01 krw Exp $ */ /* * Copyright (c) 2007,2009 Dale Rahn * Copyright (c) 2013 Raphael Graf * * Permission to use, copy, modify, and distribute this software for any * purpose with or without fee is hereby granted, provided that the above * copyright notice and this permission notice appear in all copies. * * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. */ /* * WARNING - this timer initializion has not been checked * to see if it will do _ANYTHING_ sane if the omap enters * low power mode. */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include /* registers */ #define DM_TIDR 0x000 #define DM_TIDR_MAJOR 0x00000700 #define DM_TIDR_MINOR 0x0000003f #define DM_TIOCP_CFG 0x010 #define DM_TIOCP_CFG_IDLEMODE (3<<2) #define DM_TIOCP_CFG_EMUFREE (1<<1) #define DM_TIOCP_CFG_SOFTRESET (1<<0) #define DM_TISR 0x028 #define DM_TISR_TCAR (1<<2) #define DM_TISR_OVF (1<<1) #define DM_TISR_MAT (1<<0) #define DM_TIER 0x2c #define DM_TIER_TCAR_EN (1<<2) #define DM_TIER_OVF_EN (1<<1) #define DM_TIER_MAT_EN (1<<0) #define DM_TIECR 0x30 #define DM_TIECR_TCAR_EN (1<<2) #define DM_TIECR_OVF_EN (1<<1) #define DM_TIECR_MAT_EN (1<<0) #define DM_TWER 0x034 #define DM_TWER_TCAR_EN (1<<2) #define DM_TWER_OVF_EN (1<<1) #define DM_TWER_MAT_EN (1<<0) #define DM_TCLR 0x038 #define DM_TCLR_GPO (1<<14) #define DM_TCLR_CAPT (1<<13) #define DM_TCLR_PT (1<<12) #define DM_TCLR_TRG (3<<10) #define DM_TCLR_TRG_O (1<<10) #define DM_TCLR_TRG_OM (2<<10) #define DM_TCLR_TCM (3<<8) #define DM_TCLR_TCM_RISE (1<<8) #define DM_TCLR_TCM_FALL (2<<8) #define DM_TCLR_TCM_BOTH (3<<8) #define DM_TCLR_SCPWM (1<<7) #define DM_TCLR_CE (1<<6) #define DM_TCLR_PRE (1<<5) #define DM_TCLR_PTV (7<<2) #define DM_TCLR_AR (1<<1) #define DM_TCLR_ST (1<<0) #define DM_TCRR 0x03c #define DM_TLDR 0x040 #define DM_TTGR 0x044 #define DM_TWPS 0x048 #define DM_TWPS_TMAR (1<<4) #define DM_TWPS_TTGR (1<<3) #define DM_TWPS_TLDR (1<<2) #define DM_TWPS_TCLR (1<<0) #define DM_TWPS_TCRR (1<<1) #define DM_TWPS_ALL 0x1f #define DM_TMAR 0x04c #define DM_TCAR 0x050 #define DM_TSICR 0x054 #define DM_TSICR_POSTED (1<<2) #define DM_TSICR_SFT (1<<1) #define DM_TCAR2 0x058 #define TIMER_FREQUENCY 32768 /* 32kHz is used, selectable */ #define MAX_TIMERS 2 static struct evcount clk_count; static struct evcount stat_count; void dmtimer_attach(struct device *parent, struct device *self, void *args); int dmtimer_intr(void *frame); void dmtimer_wait(int reg); void dmtimer_cpu_initclocks(void); void dmtimer_delay(u_int); void dmtimer_setstatclockrate(int newhz); u_int dmtimer_get_timecount(struct timecounter *); static struct timecounter dmtimer_timecounter = { dmtimer_get_timecount, NULL, 0xffffffff, 0, "dmtimer", 0, NULL }; bus_space_handle_t dmtimer_ioh0; int dmtimer_irq = 0; struct dmtimer_softc { struct device sc_dev; bus_space_tag_t sc_iot; bus_space_handle_t sc_ioh[MAX_TIMERS]; u_int32_t sc_irq; u_int32_t sc_ticks_per_second; u_int32_t sc_ticks_per_intr; u_int32_t sc_ticks_err_cnt; u_int32_t sc_ticks_err_sum; u_int32_t sc_statvar; u_int32_t sc_statmin; u_int32_t sc_nexttickevent; u_int32_t sc_nextstatevent; }; struct cfattach dmtimer_ca = { sizeof (struct dmtimer_softc), NULL, dmtimer_attach }; struct cfdriver dmtimer_cd = { NULL, "dmtimer", DV_DULL }; void dmtimer_attach(struct device *parent, struct device *self, void *args) { struct dmtimer_softc *sc = (struct dmtimer_softc *)self; struct armv7_attach_args *aa = args; bus_space_handle_t ioh; u_int32_t rev, cfg; sc->sc_iot = aa->aa_iot; if (bus_space_map(sc->sc_iot, aa->aa_dev->mem[0].addr, aa->aa_dev->mem[0].size, 0, &ioh)) panic("%s: bus_space_map failed!\n", __func__); prcm_setclock(1, PRCM_CLK_SPEED_32); prcm_setclock(2, PRCM_CLK_SPEED_32); prcm_enablemodule(PRCM_TIMER2); prcm_enablemodule(PRCM_TIMER3); /* reset */ bus_space_write_4(sc->sc_iot, ioh, DM_TIOCP_CFG, DM_TIOCP_CFG_SOFTRESET); while (bus_space_read_4(sc->sc_iot, ioh, DM_TIOCP_CFG) & DM_TIOCP_CFG_SOFTRESET) ; if (self->dv_unit == 0) { dmtimer_ioh0 = ioh; dmtimer_irq = aa->aa_dev->irq[0]; /* enable write posted mode */ bus_space_write_4(sc->sc_iot, ioh, DM_TSICR, DM_TSICR_POSTED); /* stop timer */ bus_space_write_4(sc->sc_iot, ioh, DM_TCLR, 0); } else if (self->dv_unit == 1) { /* start timer because it is used in delay */ /* interrupts and posted mode are disabled */ sc->sc_irq = dmtimer_irq; sc->sc_ioh[0] = dmtimer_ioh0; sc->sc_ioh[1] = ioh; bus_space_write_4(sc->sc_iot, ioh, DM_TCRR, 0); bus_space_write_4(sc->sc_iot, ioh, DM_TLDR, 0); bus_space_write_4(sc->sc_iot, ioh, DM_TCLR, DM_TCLR_AR | DM_TCLR_ST); dmtimer_timecounter.tc_frequency = TIMER_FREQUENCY; dmtimer_timecounter.tc_priv = sc; tc_init(&dmtimer_timecounter); arm_clock_register(dmtimer_cpu_initclocks, dmtimer_delay, dmtimer_setstatclockrate, NULL); } else panic("attaching too many dmtimers at 0x%lx", aa->aa_dev->mem[0].addr); /* set IDLEMODE to smart-idle */ cfg = bus_space_read_4(sc->sc_iot, ioh, DM_TIOCP_CFG); bus_space_write_4(sc->sc_iot, ioh, DM_TIOCP_CFG, (cfg & ~DM_TIOCP_CFG_IDLEMODE) | 0x02); rev = bus_space_read_4(sc->sc_iot, ioh, DM_TIDR); printf(" rev %d.%d\n", (rev & DM_TIDR_MAJOR) >> 8, rev & DM_TIDR_MINOR); } /* * See comment in arm/xscale/i80321_clock.c * * Counter is count up, but with autoreload timers it is not possible * to detect how many interrupts passed while interrupts were blocked. * Also it is not possible to atomically add to the register. * * To work around this two timers are used, one is used as a reference * clock without reload, however we just disable the interrupt it * could generate. * * Internally this keeps track of when the next timer should fire * and based on that time and the current value of the reference * clock a number is written into the timer count register to schedule * the next event. */ int dmtimer_intr(void *frame) { struct dmtimer_softc *sc = dmtimer_cd.cd_devs[1]; u_int32_t now, r, nextevent; int32_t duration; now = bus_space_read_4(sc->sc_iot, sc->sc_ioh[1], DM_TCRR); while ((int32_t) (sc->sc_nexttickevent - now) <= 0) { sc->sc_nexttickevent += sc->sc_ticks_per_intr; sc->sc_ticks_err_sum += sc->sc_ticks_err_cnt; while (sc->sc_ticks_err_sum > hz) { sc->sc_nexttickevent += 1; sc->sc_ticks_err_sum -= hz; } clk_count.ec_count++; hardclock(frame); } while ((int32_t) (sc->sc_nextstatevent - now) <= 0) { do { r = random() & (sc->sc_statvar - 1); } while (r == 0); /* random == 0 not allowed */ sc->sc_nextstatevent += sc->sc_statmin + r; stat_count.ec_count++; statclock(frame); } if ((sc->sc_nexttickevent - now) < (sc->sc_nextstatevent - now)) nextevent = sc->sc_nexttickevent; else nextevent = sc->sc_nextstatevent; duration = nextevent - bus_space_read_4(sc->sc_iot, sc->sc_ioh[1], DM_TCRR); if (duration <= 0) duration = 1; /* trigger immediately. */ if (duration > sc->sc_ticks_per_intr + 1) { printf("%s: time lost!\n", __func__); /* * If interrupts are blocked too long, like during * the root prompt or ddb, the timer can roll over, * this will allow the system to continue to run * even if time is lost. */ duration = sc->sc_ticks_per_intr; sc->sc_nexttickevent = now; sc->sc_nextstatevent = now; } bus_space_write_4(sc->sc_iot, sc->sc_ioh[0], DM_TISR, bus_space_read_4(sc->sc_iot, sc->sc_ioh[0], DM_TISR)); bus_space_write_4(sc->sc_iot, sc->sc_ioh[0], DM_TCRR, -duration); dmtimer_wait(DM_TWPS_ALL); return 1; } /* * would be interesting to play with trigger mode while having one timer * in 32KHz mode, and the other timer running in sysclk mode and use * the high resolution speeds (matters more for delay than tick timer */ void dmtimer_cpu_initclocks() { struct dmtimer_softc *sc = dmtimer_cd.cd_devs[1]; stathz = 128; profhz = 1024; sc->sc_ticks_per_second = TIMER_FREQUENCY; /* 32768 */ setstatclockrate(stathz); sc->sc_ticks_per_intr = sc->sc_ticks_per_second / hz; sc->sc_ticks_err_cnt = sc->sc_ticks_per_second % hz; sc->sc_ticks_err_sum = 0; /* establish interrupts */ arm_intr_establish(sc->sc_irq, IPL_CLOCK, dmtimer_intr, NULL, "tick"); /* setup timer 0 */ bus_space_write_4(sc->sc_iot, sc->sc_ioh[0], DM_TLDR, 0); sc->sc_nexttickevent = sc->sc_nextstatevent = bus_space_read_4(sc->sc_iot, sc->sc_ioh[1], DM_TCRR) + sc->sc_ticks_per_intr; bus_space_write_4(sc->sc_iot, sc->sc_ioh[0], DM_TIER, DM_TIER_OVF_EN); bus_space_write_4(sc->sc_iot, sc->sc_ioh[0], DM_TWER, DM_TWER_OVF_EN); bus_space_write_4(sc->sc_iot, sc->sc_ioh[0], DM_TISR, /*clear interrupt flags */ bus_space_read_4(sc->sc_iot, sc->sc_ioh[0], DM_TISR)); bus_space_write_4(sc->sc_iot, sc->sc_ioh[0], DM_TCRR, -sc->sc_ticks_per_intr); dmtimer_wait(DM_TWPS_ALL); bus_space_write_4(sc->sc_iot, sc->sc_ioh[0], DM_TCLR, /* autoreload and start */ DM_TCLR_AR | DM_TCLR_ST); dmtimer_wait(DM_TWPS_ALL); } void dmtimer_wait(int reg) { struct dmtimer_softc *sc = dmtimer_cd.cd_devs[1]; while (bus_space_read_4(sc->sc_iot, sc->sc_ioh[0], DM_TWPS) & reg) ; } void dmtimer_delay(u_int usecs) { struct dmtimer_softc *sc = dmtimer_cd.cd_devs[1]; u_int32_t clock, oclock, delta, delaycnt; volatile int j; int csec, usec; if (usecs > (0x80000000 / (TIMER_FREQUENCY))) { csec = usecs / 10000; usec = usecs % 10000; delaycnt = (TIMER_FREQUENCY / 100) * csec + (TIMER_FREQUENCY / 100) * usec / 10000; } else { delaycnt = TIMER_FREQUENCY * usecs / 1000000; } if (delaycnt <= 1) for (j = 100; j > 0; j--) ; if (sc->sc_ioh[1] == 0) { /* BAH */ for (; usecs > 0; usecs--) for (j = 100; j > 0; j--) ; return; } oclock = bus_space_read_4(sc->sc_iot, sc->sc_ioh[1], DM_TCRR); while (1) { for (j = 100; j > 0; j--) ; clock = bus_space_read_4(sc->sc_iot, sc->sc_ioh[1], DM_TCRR); delta = clock - oclock; if (delta > delaycnt) break; } } void dmtimer_setstatclockrate(int newhz) { struct dmtimer_softc *sc = dmtimer_cd.cd_devs[1]; int minint, statint; int s; s = splclock(); statint = sc->sc_ticks_per_second / newhz; /* calculate largest 2^n which is smaller than just over half statint */ sc->sc_statvar = 0x40000000; /* really big power of two */ minint = statint / 2 + 100; while (sc->sc_statvar > minint) sc->sc_statvar >>= 1; sc->sc_statmin = statint - (sc->sc_statvar >> 1); splx(s); /* * XXX this allows the next stat timer to occur then it switches * to the new frequency. Rather than switching instantly. */ } u_int dmtimer_get_timecount(struct timecounter *tc) { struct dmtimer_softc *sc = dmtimer_timecounter.tc_priv; return bus_space_read_4(sc->sc_iot, sc->sc_ioh[1], DM_TCRR); }