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Diffstat (limited to 'arch/arm/mach-omap2/timer.c')
| -rw-r--r-- | arch/arm/mach-omap2/timer.c | 342 | 
1 files changed, 342 insertions, 0 deletions
diff --git a/arch/arm/mach-omap2/timer.c b/arch/arm/mach-omap2/timer.c new file mode 100644 index 00000000000..e9640728239 --- /dev/null +++ b/arch/arm/mach-omap2/timer.c @@ -0,0 +1,342 @@ +/* + * linux/arch/arm/mach-omap2/timer.c + * + * OMAP2 GP timer support. + * + * Copyright (C) 2009 Nokia Corporation + * + * Update to use new clocksource/clockevent layers + * Author: Kevin Hilman, MontaVista Software, Inc. <source@mvista.com> + * Copyright (C) 2007 MontaVista Software, Inc. + * + * Original driver: + * Copyright (C) 2005 Nokia Corporation + * Author: Paul Mundt <paul.mundt@nokia.com> + *         Juha Yrjölä <juha.yrjola@nokia.com> + * OMAP Dual-mode timer framework support by Timo Teras + * + * Some parts based off of TI's 24xx code: + * + * Copyright (C) 2004-2009 Texas Instruments, Inc. + * + * Roughly modelled after the OMAP1 MPU timer code. + * Added OMAP4 support - Santosh Shilimkar <santosh.shilimkar@ti.com> + * + * This file is subject to the terms and conditions of the GNU General Public + * License. See the file "COPYING" in the main directory of this archive + * for more details. + */ +#include <linux/init.h> +#include <linux/time.h> +#include <linux/interrupt.h> +#include <linux/err.h> +#include <linux/clk.h> +#include <linux/delay.h> +#include <linux/irq.h> +#include <linux/clocksource.h> +#include <linux/clockchips.h> + +#include <asm/mach/time.h> +#include <plat/dmtimer.h> +#include <asm/localtimer.h> +#include <asm/sched_clock.h> +#include <plat/common.h> +#include <plat/omap_hwmod.h> + +/* Parent clocks, eventually these will come from the clock framework */ + +#define OMAP2_MPU_SOURCE	"sys_ck" +#define OMAP3_MPU_SOURCE	OMAP2_MPU_SOURCE +#define OMAP4_MPU_SOURCE	"sys_clkin_ck" +#define OMAP2_32K_SOURCE	"func_32k_ck" +#define OMAP3_32K_SOURCE	"omap_32k_fck" +#define OMAP4_32K_SOURCE	"sys_32k_ck" + +#ifdef CONFIG_OMAP_32K_TIMER +#define OMAP2_CLKEV_SOURCE	OMAP2_32K_SOURCE +#define OMAP3_CLKEV_SOURCE	OMAP3_32K_SOURCE +#define OMAP4_CLKEV_SOURCE	OMAP4_32K_SOURCE +#define OMAP3_SECURE_TIMER	12 +#else +#define OMAP2_CLKEV_SOURCE	OMAP2_MPU_SOURCE +#define OMAP3_CLKEV_SOURCE	OMAP3_MPU_SOURCE +#define OMAP4_CLKEV_SOURCE	OMAP4_MPU_SOURCE +#define OMAP3_SECURE_TIMER	1 +#endif + +/* MAX_GPTIMER_ID: number of GPTIMERs on the chip */ +#define MAX_GPTIMER_ID		12 + +u32 sys_timer_reserved; + +/* Clockevent code */ + +static struct omap_dm_timer clkev; +static struct clock_event_device clockevent_gpt; + +static irqreturn_t omap2_gp_timer_interrupt(int irq, void *dev_id) +{ +	struct clock_event_device *evt = &clockevent_gpt; + +	__omap_dm_timer_write_status(clkev.io_base, OMAP_TIMER_INT_OVERFLOW); + +	evt->event_handler(evt); +	return IRQ_HANDLED; +} + +static struct irqaction omap2_gp_timer_irq = { +	.name		= "gp timer", +	.flags		= IRQF_DISABLED | IRQF_TIMER | IRQF_IRQPOLL, +	.handler	= omap2_gp_timer_interrupt, +}; + +static int omap2_gp_timer_set_next_event(unsigned long cycles, +					 struct clock_event_device *evt) +{ +	__omap_dm_timer_load_start(clkev.io_base, OMAP_TIMER_CTRL_ST, +						0xffffffff - cycles, 1); + +	return 0; +} + +static void omap2_gp_timer_set_mode(enum clock_event_mode mode, +				    struct clock_event_device *evt) +{ +	u32 period; + +	__omap_dm_timer_stop(clkev.io_base, 1, clkev.rate); + +	switch (mode) { +	case CLOCK_EVT_MODE_PERIODIC: +		period = clkev.rate / HZ; +		period -= 1; +		/* Looks like we need to first set the load value separately */ +		__omap_dm_timer_write(clkev.io_base, OMAP_TIMER_LOAD_REG, +					0xffffffff - period, 1); +		__omap_dm_timer_load_start(clkev.io_base, +					OMAP_TIMER_CTRL_AR | OMAP_TIMER_CTRL_ST, +						0xffffffff - period, 1); +		break; +	case CLOCK_EVT_MODE_ONESHOT: +		break; +	case CLOCK_EVT_MODE_UNUSED: +	case CLOCK_EVT_MODE_SHUTDOWN: +	case CLOCK_EVT_MODE_RESUME: +		break; +	} +} + +static struct clock_event_device clockevent_gpt = { +	.name		= "gp timer", +	.features       = CLOCK_EVT_FEAT_PERIODIC | CLOCK_EVT_FEAT_ONESHOT, +	.shift		= 32, +	.set_next_event	= omap2_gp_timer_set_next_event, +	.set_mode	= omap2_gp_timer_set_mode, +}; + +static int __init omap_dm_timer_init_one(struct omap_dm_timer *timer, +						int gptimer_id, +						const char *fck_source) +{ +	char name[10]; /* 10 = sizeof("gptXX_Xck0") */ +	struct omap_hwmod *oh; +	size_t size; +	int res = 0; + +	sprintf(name, "timer%d", gptimer_id); +	omap_hwmod_setup_one(name); +	oh = omap_hwmod_lookup(name); +	if (!oh) +		return -ENODEV; + +	timer->irq = oh->mpu_irqs[0].irq; +	timer->phys_base = oh->slaves[0]->addr->pa_start; +	size = oh->slaves[0]->addr->pa_end - timer->phys_base; + +	/* Static mapping, never released */ +	timer->io_base = ioremap(timer->phys_base, size); +	if (!timer->io_base) +		return -ENXIO; + +	/* After the dmtimer is using hwmod these clocks won't be needed */ +	sprintf(name, "gpt%d_fck", gptimer_id); +	timer->fclk = clk_get(NULL, name); +	if (IS_ERR(timer->fclk)) +		return -ENODEV; + +	sprintf(name, "gpt%d_ick", gptimer_id); +	timer->iclk = clk_get(NULL, name); +	if (IS_ERR(timer->iclk)) { +		clk_put(timer->fclk); +		return -ENODEV; +	} + +	omap_hwmod_enable(oh); + +	sys_timer_reserved |= (1 << (gptimer_id - 1)); + +	if (gptimer_id != 12) { +		struct clk *src; + +		src = clk_get(NULL, fck_source); +		if (IS_ERR(src)) { +			res = -EINVAL; +		} else { +			res = __omap_dm_timer_set_source(timer->fclk, src); +			if (IS_ERR_VALUE(res)) +				pr_warning("%s: timer%i cannot set source\n", +						__func__, gptimer_id); +			clk_put(src); +		} +	} +	__omap_dm_timer_reset(timer->io_base, 1, 1); +	timer->posted = 1; + +	timer->rate = clk_get_rate(timer->fclk); + +	timer->reserved = 1; + +	return res; +} + +static void __init omap2_gp_clockevent_init(int gptimer_id, +						const char *fck_source) +{ +	int res; + +	res = omap_dm_timer_init_one(&clkev, gptimer_id, fck_source); +	BUG_ON(res); + +	omap2_gp_timer_irq.dev_id = (void *)&clkev; +	setup_irq(clkev.irq, &omap2_gp_timer_irq); + +	__omap_dm_timer_int_enable(clkev.io_base, OMAP_TIMER_INT_OVERFLOW); + +	clockevent_gpt.mult = div_sc(clkev.rate, NSEC_PER_SEC, +				     clockevent_gpt.shift); +	clockevent_gpt.max_delta_ns = +		clockevent_delta2ns(0xffffffff, &clockevent_gpt); +	clockevent_gpt.min_delta_ns = +		clockevent_delta2ns(3, &clockevent_gpt); +		/* Timer internal resynch latency. */ + +	clockevent_gpt.cpumask = cpumask_of(0); +	clockevents_register_device(&clockevent_gpt); + +	pr_info("OMAP clockevent source: GPTIMER%d at %lu Hz\n", +		gptimer_id, clkev.rate); +} + +/* Clocksource code */ + +#ifdef CONFIG_OMAP_32K_TIMER +/* + * When 32k-timer is enabled, don't use GPTimer for clocksource + * instead, just leave default clocksource which uses the 32k + * sync counter.  See clocksource setup in plat-omap/counter_32k.c + */ + +static void __init omap2_gp_clocksource_init(int unused, const char *dummy) +{ +	omap_init_clocksource_32k(); +} + +#else + +static struct omap_dm_timer clksrc; + +/* + * clocksource + */ +static DEFINE_CLOCK_DATA(cd); +static cycle_t clocksource_read_cycles(struct clocksource *cs) +{ +	return (cycle_t)__omap_dm_timer_read_counter(clksrc.io_base, 1); +} + +static struct clocksource clocksource_gpt = { +	.name		= "gp timer", +	.rating		= 300, +	.read		= clocksource_read_cycles, +	.mask		= CLOCKSOURCE_MASK(32), +	.flags		= CLOCK_SOURCE_IS_CONTINUOUS, +}; + +static void notrace dmtimer_update_sched_clock(void) +{ +	u32 cyc; + +	cyc = __omap_dm_timer_read_counter(clksrc.io_base, 1); + +	update_sched_clock(&cd, cyc, (u32)~0); +} + +unsigned long long notrace sched_clock(void) +{ +	u32 cyc = 0; + +	if (clksrc.reserved) +		cyc = __omap_dm_timer_read_counter(clksrc.io_base, 1); + +	return cyc_to_sched_clock(&cd, cyc, (u32)~0); +} + +/* Setup free-running counter for clocksource */ +static void __init omap2_gp_clocksource_init(int gptimer_id, +						const char *fck_source) +{ +	int res; + +	res = omap_dm_timer_init_one(&clksrc, gptimer_id, fck_source); +	BUG_ON(res); + +	pr_info("OMAP clocksource: GPTIMER%d at %lu Hz\n", +		gptimer_id, clksrc.rate); + +	__omap_dm_timer_load_start(clksrc.io_base, OMAP_TIMER_CTRL_ST, 0, 1); +	init_sched_clock(&cd, dmtimer_update_sched_clock, 32, clksrc.rate); + +	if (clocksource_register_hz(&clocksource_gpt, clksrc.rate)) +		pr_err("Could not register clocksource %s\n", +			clocksource_gpt.name); +} +#endif + +#define OMAP_SYS_TIMER_INIT(name, clkev_nr, clkev_src,			\ +				clksrc_nr, clksrc_src)			\ +static void __init omap##name##_timer_init(void)			\ +{									\ +	omap2_gp_clockevent_init((clkev_nr), clkev_src);		\ +	omap2_gp_clocksource_init((clksrc_nr), clksrc_src);		\ +} + +#define OMAP_SYS_TIMER(name)						\ +struct sys_timer omap##name##_timer = {					\ +	.init	= omap##name##_timer_init,				\ +}; + +#ifdef CONFIG_ARCH_OMAP2 +OMAP_SYS_TIMER_INIT(2, 1, OMAP2_CLKEV_SOURCE, 2, OMAP2_MPU_SOURCE) +OMAP_SYS_TIMER(2) +#endif + +#ifdef CONFIG_ARCH_OMAP3 +OMAP_SYS_TIMER_INIT(3, 1, OMAP3_CLKEV_SOURCE, 2, OMAP3_MPU_SOURCE) +OMAP_SYS_TIMER(3) +OMAP_SYS_TIMER_INIT(3_secure, OMAP3_SECURE_TIMER, OMAP3_CLKEV_SOURCE, +			2, OMAP3_MPU_SOURCE) +OMAP_SYS_TIMER(3_secure) +#endif + +#ifdef CONFIG_ARCH_OMAP4 +static void __init omap4_timer_init(void) +{ +#ifdef CONFIG_LOCAL_TIMERS +	twd_base = ioremap(OMAP44XX_LOCAL_TWD_BASE, SZ_256); +	BUG_ON(!twd_base); +#endif +	omap2_gp_clockevent_init(1, OMAP4_CLKEV_SOURCE); +	omap2_gp_clocksource_init(2, OMAP4_MPU_SOURCE); +} +OMAP_SYS_TIMER(4) +#endif  |