timer.c

/*-
 * SPDX-License-Identifier: BSD-2-Clause
 *
 * Copyright (c) 2006 Benno Rice.
 * Copyright (C) 2007-2008 MARVELL INTERNATIONAL LTD.
 * All rights reserved.
 *
 * Adapted to Marvell SoC by Semihalf.
 *
 * 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 ``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 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.
 *
 * from: FreeBSD: //depot/projects/arm/src/sys/arm/xscale/pxa2x0/pxa2x0_timer.c, rev 1
 */

#include <sys/param.h>
#include <sys/systm.h>
#include <sys/bus.h>
#include <sys/eventhandler.h>
#include <sys/kernel.h>
#include <sys/module.h>
#include <sys/malloc.h>
#include <sys/rman.h>
#include <sys/timeet.h>
#include <sys/timetc.h>
#include <sys/watchdog.h>
#include <machine/bus.h>
#include <machine/cpu.h>
#include <machine/intr.h>
#include <machine/machdep.h>

#include <arm/mv/mvreg.h>
#include <arm/mv/mvvar.h>

#include <dev/ofw/ofw_bus.h>
#include <dev/ofw/ofw_bus_subr.h>

#define INITIAL_TIMECOUNTER	(0xffffffff)
#define MAX_WATCHDOG_TICKS	(0xffffffff)

#define	MV_TMR	0x1
#define	MV_WDT	0x2
#define	MV_NONE	0x0

#define	MV_CLOCK_SRC_ARMV7	25000000	/* Timers' 25MHz mode */

#define	WATCHDOG_TIMER_ARMV5		2

typedef void (*mv_watchdog_enable_t)(void);
typedef void (*mv_watchdog_disable_t)(void);

struct mv_timer_config {
	enum soc_family		soc_family;
	mv_watchdog_enable_t	watchdog_enable;
	mv_watchdog_disable_t	watchdog_disable;
	unsigned int 		clock_src;
	uint32_t 		bridge_irq_cause;
	uint32_t 		irq_timer0_clr;
	uint32_t 		irq_timer_wd_clr;
};

struct mv_timer_softc {
	struct resource	*	timer_res[2];
	bus_space_tag_t		timer_bst;
	bus_space_handle_t	timer_bsh;
	struct mtx		timer_mtx;
	struct eventtimer	et;
	boolean_t		has_wdt;
	struct mv_timer_config* config;
};

static struct resource_spec mv_timer_spec[] = {
	{ SYS_RES_MEMORY,	0,	RF_ACTIVE },
	{ SYS_RES_IRQ,		0,	RF_ACTIVE | RF_OPTIONAL },
	{ -1, 0 }
};

/* Interrupt is not required by MV_WDT devices */
static struct ofw_compat_data mv_timer_compat[] = {
	{"marvell,armada-380-timer",	MV_NONE },
	{"marvell,armada-xp-timer",	MV_TMR | MV_WDT },
	{"mrvl,timer",			MV_TMR | MV_WDT },
	{NULL,				MV_NONE }
};

static struct mv_timer_softc *timer_softc = NULL;
static int timers_initialized = 0;

static int	mv_timer_probe(device_t);
static int	mv_timer_attach(device_t);

static int	mv_hardclock(void *);
static unsigned mv_timer_get_timecount(struct timecounter *);

static uint32_t	mv_get_timer_control(void);
static void	mv_set_timer_control(uint32_t);
static uint32_t	mv_get_timer(uint32_t);
static void	mv_set_timer(uint32_t, uint32_t);
static void	mv_set_timer_rel(uint32_t, uint32_t);
static void	mv_watchdog_event(void *, unsigned int, int *);
static int	mv_timer_start(struct eventtimer *et,
    sbintime_t first, sbintime_t period);
static int	mv_timer_stop(struct eventtimer *et);
static void	mv_setup_timers(void);

static void mv_watchdog_enable_armadaxp(void);
static void mv_watchdog_disable_armadaxp(void);

static void mv_delay(int usec, void* arg);

static struct mv_timer_config timer_armadaxp_config =
{
	MV_SOC_ARMADA_XP,
	&mv_watchdog_enable_armadaxp,
	&mv_watchdog_disable_armadaxp,
	MV_CLOCK_SRC_ARMV7,
	BRIDGE_IRQ_CAUSE_ARMADAXP,
	IRQ_TIMER0_CLR_ARMADAXP,
	IRQ_TIMER_WD_CLR_ARMADAXP,
};

static struct ofw_compat_data mv_timer_soc_config[] = {
	{"marvell,armada-xp-timer",	(uintptr_t)&timer_armadaxp_config },
	{NULL,				(uintptr_t)NULL },
};

static struct timecounter mv_timer_timecounter = {
	.tc_get_timecount = mv_timer_get_timecount,
	.tc_name = "CPUTimer1",
	.tc_frequency = 0,	/* This is assigned on the fly in the init sequence */
	.tc_counter_mask = ~0u,
	.tc_quality = 1000,
};

static int
mv_timer_probe(device_t dev)
{

	if (!ofw_bus_status_okay(dev))
		return (ENXIO);

	if (ofw_bus_search_compatible(dev, mv_timer_compat)->ocd_data == MV_NONE)
		return (ENXIO);

	device_set_desc(dev, "Marvell CPU Timer");
	return (0);
}

static int
mv_timer_attach(device_t dev)
{
	int	error;
	void	*ihl;
	struct	mv_timer_softc *sc;
	uint32_t irq_cause, irq_mask;

	if (timer_softc != NULL)
		return (ENXIO);

	sc = (struct mv_timer_softc *)device_get_softc(dev);
	timer_softc = sc;

	sc->config = (struct mv_timer_config*)
	    ofw_bus_search_compatible(dev, mv_timer_soc_config)->ocd_data;

	if (sc->config->clock_src == 0)
		sc->config->clock_src = get_tclk();

	error = bus_alloc_resources(dev, mv_timer_spec, sc->timer_res);
	if (error) {
		device_printf(dev, "could not allocate resources\n");
		return (ENXIO);
	}

	sc->timer_bst = rman_get_bustag(sc->timer_res[0]);
	sc->timer_bsh = rman_get_bushandle(sc->timer_res[0]);

	sc->has_wdt = ofw_bus_has_prop(dev, "mrvl,has-wdt");

	mtx_init(&timer_softc->timer_mtx, "watchdog", NULL, MTX_DEF);

	if (sc->has_wdt) {
		if (sc->config->watchdog_disable)
			sc->config->watchdog_disable();
		EVENTHANDLER_REGISTER(watchdog_list, mv_watchdog_event, sc, 0);
	}

	if (ofw_bus_search_compatible(dev, mv_timer_compat)->ocd_data
	    == MV_WDT) {
		/* Don't set timers for wdt-only entry. */
		device_printf(dev, "only watchdog attached\n");
		return (0);
	} else if (sc->timer_res[1] == NULL) {
		device_printf(dev, "no interrupt resource\n");
		bus_release_resources(dev, mv_timer_spec, sc->timer_res);
		return (ENXIO);
	}

	if (bus_setup_intr(dev, sc->timer_res[1], INTR_TYPE_CLK,
	    mv_hardclock, NULL, sc, &ihl) != 0) {
		bus_release_resources(dev, mv_timer_spec, sc->timer_res);
		device_printf(dev, "Could not setup interrupt.\n");
		return (ENXIO);
	}

	mv_setup_timers();
	if (sc->config->soc_family != MV_SOC_ARMADA_XP ) {
		irq_cause = read_cpu_ctrl(sc->config->bridge_irq_cause);
		irq_cause &= sc->config->irq_timer0_clr;

		write_cpu_ctrl(sc->config->bridge_irq_cause, irq_cause);
		irq_mask = read_cpu_ctrl(BRIDGE_IRQ_MASK);
		irq_mask |= IRQ_TIMER0_MASK;
		irq_mask &= ~IRQ_TIMER1_MASK;
		write_cpu_ctrl(BRIDGE_IRQ_MASK, irq_mask);
	}
	sc->et.et_name = "CPUTimer0";
	sc->et.et_flags = ET_FLAGS_PERIODIC | ET_FLAGS_ONESHOT;
	sc->et.et_quality = 1000;

	sc->et.et_frequency = sc->config->clock_src;
	sc->et.et_min_period = (0x00000002LLU << 32) / sc->et.et_frequency;
	sc->et.et_max_period = (0xfffffffeLLU << 32) / sc->et.et_frequency;
	sc->et.et_start = mv_timer_start;
	sc->et.et_stop = mv_timer_stop;
	sc->et.et_priv = sc;
	et_register(&sc->et);
	mv_timer_timecounter.tc_frequency = sc->config->clock_src;
	tc_init(&mv_timer_timecounter);

#ifdef PLATFORM
	arm_set_delay(mv_delay, NULL);
#endif
	return (0);
}

static int
mv_hardclock(void *arg)
{
	struct	mv_timer_softc *sc;
	uint32_t irq_cause;

	irq_cause = read_cpu_ctrl(timer_softc->config->bridge_irq_cause);
	irq_cause &= timer_softc->config->irq_timer0_clr;
	write_cpu_ctrl(timer_softc->config->bridge_irq_cause, irq_cause);

	sc = (struct mv_timer_softc *)arg;
	if (sc->et.et_active)
		sc->et.et_event_cb(&sc->et, sc->et.et_arg);

	return (FILTER_HANDLED);
}

static device_method_t mv_timer_methods[] = {
	DEVMETHOD(device_probe, mv_timer_probe),
	DEVMETHOD(device_attach, mv_timer_attach),
	{ 0, 0 }
};

static driver_t mv_timer_driver = {
	"timer",
	mv_timer_methods,
	sizeof(struct mv_timer_softc),
};

DRIVER_MODULE(timer_mv, simplebus, mv_timer_driver, 0, 0);

static unsigned
mv_timer_get_timecount(struct timecounter *tc)
{

	return (INITIAL_TIMECOUNTER - mv_get_timer(1));
}

static void
mv_delay(int usec, void* arg)
{
	uint32_t	val, val_temp;
	int32_t		nticks;

	val = mv_get_timer(1);
	nticks = ((timer_softc->config->clock_src / 1000000 + 1) * usec);

	while (nticks > 0) {
		val_temp = mv_get_timer(1);
		if (val > val_temp)
			nticks -= (val - val_temp);
		else
			nticks -= (val + (INITIAL_TIMECOUNTER - val_temp));

		val = val_temp;
	}
}

#ifndef PLATFORM
void
DELAY(int usec)
{
	uint32_t	val;

	if (!timers_initialized) {
		for (; usec > 0; usec--)
			for (val = 100; val > 0; val--)
				__asm __volatile("nop" ::: "memory");
	} else {
		TSENTER();
		mv_delay(usec, NULL);
		TSEXIT();
	}
}
#endif

static uint32_t
mv_get_timer_control(void)
{

	return (bus_space_read_4(timer_softc->timer_bst,
	    timer_softc->timer_bsh, CPU_TIMER_CONTROL));
}

static void
mv_set_timer_control(uint32_t val)
{

	bus_space_write_4(timer_softc->timer_bst,
	    timer_softc->timer_bsh, CPU_TIMER_CONTROL, val);
}

static uint32_t
mv_get_timer(uint32_t timer)
{

	return (bus_space_read_4(timer_softc->timer_bst,
	    timer_softc->timer_bsh, CPU_TIMER0 + timer * 0x8));
}

static void
mv_set_timer(uint32_t timer, uint32_t val)
{

	bus_space_write_4(timer_softc->timer_bst,
	    timer_softc->timer_bsh, CPU_TIMER0 + timer * 0x8, val);
}

static void
mv_set_timer_rel(uint32_t timer, uint32_t val)
{

	bus_space_write_4(timer_softc->timer_bst,
	    timer_softc->timer_bsh, CPU_TIMER0_REL + timer * 0x8, val);
}

static void
mv_watchdog_enable_armadaxp(void)
{
	uint32_t irq_cause, val;

	irq_cause = read_cpu_ctrl(timer_softc->config->bridge_irq_cause);
	irq_cause &= timer_softc->config->irq_timer_wd_clr;
	write_cpu_ctrl(timer_softc->config->bridge_irq_cause, irq_cause);

	val = read_cpu_mp_clocks(WD_RSTOUTn_MASK);
	val |= (WD_GLOBAL_MASK | WD_CPU0_MASK);
	write_cpu_mp_clocks(WD_RSTOUTn_MASK, val);

	val = read_cpu_misc(RSTOUTn_MASK_ARMV7);
	val &= ~RSTOUTn_MASK_WD;
	write_cpu_misc(RSTOUTn_MASK_ARMV7, val);

	val = mv_get_timer_control();
	val |= CPU_TIMER2_EN | CPU_TIMER2_AUTO | CPU_TIMER_WD_25MHZ_EN;
	mv_set_timer_control(val);
}

static void
mv_watchdog_disable_armadaxp(void)
{
	uint32_t val, irq_cause;

	val = read_cpu_mp_clocks(WD_RSTOUTn_MASK);
	val &= ~(WD_GLOBAL_MASK | WD_CPU0_MASK);
	write_cpu_mp_clocks(WD_RSTOUTn_MASK, val);

	val = read_cpu_misc(RSTOUTn_MASK_ARMV7);
	val |= RSTOUTn_MASK_WD;
	write_cpu_misc(RSTOUTn_MASK_ARMV7, RSTOUTn_MASK_WD);

	irq_cause = read_cpu_ctrl(timer_softc->config->bridge_irq_cause);
	irq_cause &= timer_softc->config->irq_timer_wd_clr;
	write_cpu_ctrl(timer_softc->config->bridge_irq_cause, irq_cause);

	val = mv_get_timer_control();
	val &= ~(CPU_TIMER2_EN | CPU_TIMER2_AUTO);
	mv_set_timer_control(val);
}

/*
 * Watchdog event handler.
 */
static void
mv_watchdog_event(void *arg, unsigned int cmd, int *error)
{
	uint64_t ns;
	uint64_t ticks;

	mtx_lock(&timer_softc->timer_mtx);
	if (cmd == 0) {
		if (timer_softc->config->watchdog_disable != NULL)
			timer_softc->config->watchdog_disable();
	} else {
		/*
		 * Watchdog timeout is in nanosecs, calculation according to
		 * watchdog(9)
		 */
		ns = (uint64_t)1 << (cmd & WD_INTERVAL);
		ticks = (uint64_t)(ns * timer_softc->config->clock_src) / 1000000000;
		if (ticks > MAX_WATCHDOG_TICKS) {
			if (timer_softc->config->watchdog_disable != NULL)
				timer_softc->config->watchdog_disable();
		} else {
			mv_set_timer(WATCHDOG_TIMER_ARMV5, ticks);
			if (timer_softc->config->watchdog_enable != NULL)
				timer_softc->config->watchdog_enable();
			*error = 0;
		}
	}
	mtx_unlock(&timer_softc->timer_mtx);
}

static int
mv_timer_start(struct eventtimer *et, sbintime_t first, sbintime_t period)
{
	struct	mv_timer_softc *sc;
	uint32_t val, val1;

	/* Calculate dividers. */
	sc = (struct mv_timer_softc *)et->et_priv;
	if (period != 0)
		val = ((uint32_t)sc->et.et_frequency * period) >> 32;
	else
		val = 0;
	if (first != 0)
		val1 = ((uint32_t)sc->et.et_frequency * first) >> 32;
	else
		val1 = val;

	/* Apply configuration. */
	mv_set_timer_rel(0, val);
	mv_set_timer(0, val1);
	val = mv_get_timer_control();
	val |= CPU_TIMER0_EN;
	if (period != 0)
		val |= CPU_TIMER0_AUTO;
	else
		val &= ~CPU_TIMER0_AUTO;
	mv_set_timer_control(val);
	return (0);
}

static int
mv_timer_stop(struct eventtimer *et)
{
	uint32_t val;

	val = mv_get_timer_control();
	val &= ~(CPU_TIMER0_EN | CPU_TIMER0_AUTO);
	mv_set_timer_control(val);
	return (0);
}

static void
mv_setup_timers(void)
{
	uint32_t val;

	mv_set_timer_rel(1, INITIAL_TIMECOUNTER);
	mv_set_timer(1, INITIAL_TIMECOUNTER);
	val = mv_get_timer_control();
	val &= ~(CPU_TIMER0_EN | CPU_TIMER0_AUTO);
	val |= CPU_TIMER1_EN | CPU_TIMER1_AUTO;

	if (timer_softc->config->soc_family == MV_SOC_ARMADA_XP) {
		/* Enable 25MHz mode */
		val |= CPU_TIMER0_25MHZ_EN | CPU_TIMER1_25MHZ_EN;
	}

	mv_set_timer_control(val);
	timers_initialized = 1;
}