diff options
Diffstat (limited to 'arch/arm/mach-omap2/timer-gp.c')
| -rw-r--r-- | arch/arm/mach-omap2/timer-gp.c | 152 |
1 files changed, 137 insertions, 15 deletions
diff --git a/arch/arm/mach-omap2/timer-gp.c b/arch/arm/mach-omap2/timer-gp.c index 3234deedb94..78d05f203ff 100644 --- a/arch/arm/mach-omap2/timer-gp.c +++ b/arch/arm/mach-omap2/timer-gp.c @@ -3,6 +3,11 @@ * * OMAP2 GP timer support. * + * 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> @@ -25,24 +30,23 @@ #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 <asm/arch/dmtimer.h> static struct omap_dm_timer *gptimer; - -static inline void omap2_gp_timer_start(unsigned long load_val) -{ - omap_dm_timer_set_load(gptimer, 1, 0xffffffff - load_val); - omap_dm_timer_set_int_enable(gptimer, OMAP_TIMER_INT_OVERFLOW); - omap_dm_timer_start(gptimer); -} +static struct clock_event_device clockevent_gpt; static irqreturn_t omap2_gp_timer_interrupt(int irq, void *dev_id) { - omap_dm_timer_write_status(gptimer, OMAP_TIMER_INT_OVERFLOW); - timer_tick(); + struct omap_dm_timer *gpt = (struct omap_dm_timer *)dev_id; + struct clock_event_device *evt = &clockevent_gpt; + + omap_dm_timer_write_status(gpt, OMAP_TIMER_INT_OVERFLOW); + evt->event_handler(evt); return IRQ_HANDLED; } @@ -52,20 +56,138 @@ static struct irqaction omap2_gp_timer_irq = { .handler = omap2_gp_timer_interrupt, }; -static void __init omap2_gp_timer_init(void) +static int omap2_gp_timer_set_next_event(unsigned long cycles, + struct clock_event_device *evt) { - u32 tick_period; + omap_dm_timer_set_load(gptimer, 0, 0xffffffff - cycles); + omap_dm_timer_start(gptimer); + + 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(gptimer); + + switch (mode) { + case CLOCK_EVT_MODE_PERIODIC: + period = clk_get_rate(omap_dm_timer_get_fclk(gptimer)) / HZ; + period -= 1; + + omap_dm_timer_set_load(gptimer, 1, 0xffffffff - period); + omap_dm_timer_start(gptimer); + 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 void __init omap2_gp_clockevent_init(void) +{ + u32 tick_rate; - omap_dm_timer_init(); gptimer = omap_dm_timer_request_specific(1); BUG_ON(gptimer == NULL); +#if defined(CONFIG_OMAP_32K_TIMER) + omap_dm_timer_set_source(gptimer, OMAP_TIMER_SRC_32_KHZ); +#else omap_dm_timer_set_source(gptimer, OMAP_TIMER_SRC_SYS_CLK); - tick_period = clk_get_rate(omap_dm_timer_get_fclk(gptimer)) / HZ; - tick_period -= 1; +#endif + tick_rate = clk_get_rate(omap_dm_timer_get_fclk(gptimer)); + omap2_gp_timer_irq.dev_id = (void *)gptimer; setup_irq(omap_dm_timer_get_irq(gptimer), &omap2_gp_timer_irq); - omap2_gp_timer_start(tick_period); + omap_dm_timer_set_int_enable(gptimer, OMAP_TIMER_INT_OVERFLOW); + + clockevent_gpt.mult = div_sc(tick_rate, NSEC_PER_SEC, + clockevent_gpt.shift); + clockevent_gpt.max_delta_ns = + clockevent_delta2ns(0xffffffff, &clockevent_gpt); + clockevent_gpt.min_delta_ns = + clockevent_delta2ns(1, &clockevent_gpt); + + clockevent_gpt.cpumask = cpumask_of_cpu(0); + clockevents_register_device(&clockevent_gpt); +} + +#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 see plat-omap/common.c. + */ + +static inline void __init omap2_gp_clocksource_init(void) {} +#else +/* + * clocksource + */ +static struct omap_dm_timer *gpt_clocksource; +static cycle_t clocksource_read_cycles(void) +{ + return (cycle_t)omap_dm_timer_read_counter(gpt_clocksource); +} + +static struct clocksource clocksource_gpt = { + .name = "gp timer", + .rating = 300, + .read = clocksource_read_cycles, + .mask = CLOCKSOURCE_MASK(32), + .shift = 24, + .flags = CLOCK_SOURCE_IS_CONTINUOUS, +}; + +/* Setup free-running counter for clocksource */ +static void __init omap2_gp_clocksource_init(void) +{ + static struct omap_dm_timer *gpt; + u32 tick_rate, tick_period; + static char err1[] __initdata = KERN_ERR + "%s: failed to request dm-timer\n"; + static char err2[] __initdata = KERN_ERR + "%s: can't register clocksource!\n"; + + gpt = omap_dm_timer_request(); + if (!gpt) + printk(err1, clocksource_gpt.name); + gpt_clocksource = gpt; + + omap_dm_timer_set_source(gpt, OMAP_TIMER_SRC_SYS_CLK); + tick_rate = clk_get_rate(omap_dm_timer_get_fclk(gpt)); + tick_period = (tick_rate / HZ) - 1; + + omap_dm_timer_set_load(gpt, 1, 0); + omap_dm_timer_start(gpt); + + clocksource_gpt.mult = + clocksource_khz2mult(tick_rate/1000, clocksource_gpt.shift); + if (clocksource_register(&clocksource_gpt)) + printk(err2, clocksource_gpt.name); +} +#endif + +static void __init omap2_gp_timer_init(void) +{ + omap_dm_timer_init(); + + omap2_gp_clockevent_init(); + omap2_gp_clocksource_init(); } struct sys_timer omap_timer = { |