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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 |