diff options
Diffstat (limited to 'sys/arm/at91/at91_pit.c')
-rw-r--r-- | sys/arm/at91/at91_pit.c | 233 |
1 files changed, 233 insertions, 0 deletions
diff --git a/sys/arm/at91/at91_pit.c b/sys/arm/at91/at91_pit.c new file mode 100644 index 0000000..516b4d4 --- /dev/null +++ b/sys/arm/at91/at91_pit.c @@ -0,0 +1,233 @@ +/*- + * Copyright (c) 2010 Yohanes Nugroho. 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 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 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 <sys/cdefs.h> + +#include <sys/param.h> +#include <sys/systm.h> +#include <sys/kernel.h> +#include <sys/module.h> +#include <sys/time.h> +#include <sys/bus.h> +#include <sys/resource.h> +#include <sys/timetc.h> +#include <sys/watchdog.h> + +#include <machine/bus.h> +#include <machine/cpu.h> +#include <machine/cpufunc.h> +#include <machine/resource.h> +#include <machine/frame.h> +#include <machine/intr.h> + +#include <arm/at91/at91var.h> +#include <arm/at91/at91_pitreg.h> +#include <arm/at91/at91_pmcvar.h> +#include <arm/at91/at91sam9g20reg.h> + +__FBSDID("$FreeBSD$"); + +static struct at91pit_softc { + bus_space_tag_t sc_st; + bus_space_handle_t sc_sh; + device_t sc_dev; +} *pit_softc; + +#define RD4(off) \ + bus_space_read_4(pit_softc->sc_st, pit_softc->sc_sh, (off)) +#define WR4(off, val) \ + bus_space_write_4(pit_softc->sc_st, pit_softc->sc_sh, (off), (val)) + +static unsigned at91pit_get_timecount(struct timecounter *tc); +static int clock_intr(void *arg); + +static struct timecounter at91pit_timecounter = { + at91pit_get_timecount, /* get_timecount */ + NULL, /* no poll_pps */ + 0xffffffffu, /* counter mask */ + 0, /* frequency */ + "AT91SAM9261 timer", /* name */ + 1000 /* quality */ +}; + + +uint32_t +at91_pit_base(void); + +uint32_t +at91_pit_size(void); + +static int +at91pit_probe(device_t dev) +{ + device_set_desc(dev, "PIT"); + return (0); +} + +uint32_t +at91_pit_base(void) +{ + return (AT91SAM9G20_PIT_BASE); +} + +uint32_t +at91_pit_size(void) +{ + return (AT91SAM9G20_PIT_SIZE); +} + +static int pit_rate; +static int pit_cycle; +static int pit_counter; + +static int +at91pit_attach(device_t dev) +{ + struct at91_softc *sc = device_get_softc(device_get_parent(dev)); + struct resource *irq; + int rid = 0; + void *ih; + + pit_softc = device_get_softc(dev); + pit_softc->sc_st = sc->sc_st; + pit_softc->sc_dev = dev; + if (bus_space_subregion(sc->sc_st, sc->sc_sh, at91_pit_base(), + at91_pit_size(), &pit_softc->sc_sh) != 0) + panic("couldn't subregion pit registers"); + + irq = bus_alloc_resource(dev, SYS_RES_IRQ, &rid, 1, 1, 1, + RF_ACTIVE | RF_SHAREABLE); + if (!irq) + panic("Unable to allocate IRQ for the system timer"); + else + bus_setup_intr(dev, irq, INTR_TYPE_CLK, + clock_intr, NULL, NULL, &ih); + + + device_printf(dev, "AT91SAM9x pit registered\n"); + return (0); +} + +static device_method_t at91pit_methods[] = { + DEVMETHOD(device_probe, at91pit_probe), + DEVMETHOD(device_attach, at91pit_attach), + {0,0}, +}; + +static driver_t at91pit_driver = { + "at91_pit", + at91pit_methods, + sizeof(struct at91pit_softc), +}; + +static devclass_t at91pit_devclass; + +DRIVER_MODULE(at91_pit, atmelarm, at91pit_driver, at91pit_devclass, 0, 0); + +static int +clock_intr(void *arg) +{ + + struct trapframe *fp = arg; + + if (RD4(PIT_SR) & PIT_PITS_DONE) { + uint32_t pivr = RD4(PIT_PIVR); + if (PIT_CNT(pivr)>1) { + printf("cnt = %d\n", PIT_CNT(pivr)); + } + pit_counter += pit_cycle; + hardclock(TRAPF_USERMODE(fp), TRAPF_PC(fp)); + return (FILTER_HANDLED); + } + return (FILTER_STRAY); +} + +static unsigned +at91pit_get_timecount(struct timecounter *tc) +{ + return pit_counter; +} + +/*todo: review this*/ +void +DELAY(int n) +{ + u_int32_t start, end, cur; + + start = RD4(PIT_PIIR); + n = (n * 1000) / (at91_master_clock / 12); + if (n <= 0) + n = 1; + end = (start + n); + cur = start; + if (start > end) { + while (cur >= start || cur < end) + cur = RD4(PIT_PIIR); + } else { + while (cur < end) + cur = RD4(PIT_PIIR); + } +} + +/* + * The 3 next functions must be implement with the futur PLL code. + */ +void +cpu_startprofclock(void) +{ +} + +void +cpu_stopprofclock(void) +{ +} + +#define HZ 100 + +void +cpu_initclocks(void) +{ + struct at91_pmc_clock *master; + + master = at91_pmc_clock_ref("mck"); + pit_rate = master->hz / 16; + pit_cycle = (pit_rate + HZ/2) / HZ; + at91pit_timecounter.tc_frequency = pit_rate; + WR4(PIT_MR, 0); + + while (PIT_PIV(RD4(PIT_PIVR)) != 0); + + WR4(PIT_MR, (pit_cycle - 1) | PIT_IEN | PIT_EN); + tc_init(&at91pit_timecounter); +} + +void +cpu_reset(void) +{ + *(volatile int *)(AT91SAM9G20_BASE + AT91SAM9G20_RSTC_BASE + + RSTC_CR) = RSTC_PROCRST | RSTC_PERRST | RSTC_KEY; + while (1) + continue; +} |