diff options
author | Rabin Vincent <rabin@rab.in> | 2015-03-08 15:29:12 (GMT) |
---|---|---|
committer | Jesper Nilsson <jespern@axis.com> | 2015-03-25 10:03:40 (GMT) |
commit | ed9fd3ff0251783cb3943e71aac398b9064efae6 (patch) | |
tree | 37082935bde7a51e91e42ff8521e9ea89780f3b7 /arch/cris/arch-v32/kernel/time.c | |
parent | 16428f943d192390b4673612b1d3fb81772323d9 (diff) | |
download | linux-ed9fd3ff0251783cb3943e71aac398b9064efae6.tar.xz |
CRISv32: use generic clockevents
Implement a oneshot-capable clockevents device so we get support for
things like hrtimers and NOHZ.
Signed-off-by: Rabin Vincent <rabin@rab.in>
Signed-off-by: Jesper Nilsson <jespern@axis.com>
Diffstat (limited to 'arch/cris/arch-v32/kernel/time.c')
-rw-r--r-- | arch/cris/arch-v32/kernel/time.c | 145 |
1 files changed, 85 insertions, 60 deletions
diff --git a/arch/cris/arch-v32/kernel/time.c b/arch/cris/arch-v32/kernel/time.c index aa2d94b..77e241d 100644 --- a/arch/cris/arch-v32/kernel/time.c +++ b/arch/cris/arch-v32/kernel/time.c @@ -8,6 +8,7 @@ #include <linux/timex.h> #include <linux/time.h> #include <linux/clocksource.h> +#include <linux/clockchips.h> #include <linux/interrupt.h> #include <linux/swap.h> #include <linux/sched.h> @@ -36,6 +37,8 @@ /* Number of 763 counts before watchdog bites */ #define ETRAX_WD_CNT ((2*ETRAX_WD_HZ)/HZ + 1) +#define CRISV32_TIMER_FREQ (100000000lu) + /* Register the continuos readonly timer available in FS and ARTPEC-3. */ static cycle_t read_cont_rotime(struct clocksource *cs) { @@ -186,81 +189,99 @@ void handle_watchdog_bite(struct pt_regs *regs) #endif } -/* - * timer_interrupt() needs to keep up the real-time clock, - * as well as call the "xtime_update()" routine every clocktick. - */ -extern void cris_do_profile(struct pt_regs *regs); +extern void cris_profile_sample(struct pt_regs *regs); +static void __iomem *timer_base; -static inline irqreturn_t timer_interrupt(int irq, void *dev_id) +static void crisv32_clkevt_mode(enum clock_event_mode mode, + struct clock_event_device *dev) { - struct pt_regs *regs = get_irq_regs(); - int cpu = smp_processor_id(); - reg_timer_r_masked_intr masked_intr; - reg_timer_rw_ack_intr ack_intr = { 0 }; - - /* Check if the timer interrupt is for us (a tmr0 int) */ - masked_intr = REG_RD(timer, timer_regs[cpu], r_masked_intr); - if (!masked_intr.tmr0) - return IRQ_NONE; + reg_timer_rw_tmr0_ctrl ctrl = { + .op = regk_timer_hold, + .freq = regk_timer_f100, + }; - /* Acknowledge the timer irq. */ - ack_intr.tmr0 = 1; - REG_WR(timer, timer_regs[cpu], rw_ack_intr, ack_intr); + REG_WR(timer, timer_base, rw_tmr0_ctrl, ctrl); +} - /* Reset watchdog otherwise it resets us! */ - reset_watchdog(); +static int crisv32_clkevt_next_event(unsigned long evt, + struct clock_event_device *dev) +{ + reg_timer_rw_tmr0_ctrl ctrl = { + .op = regk_timer_ld, + .freq = regk_timer_f100, + }; + + REG_WR(timer, timer_base, rw_tmr0_div, evt); + REG_WR(timer, timer_base, rw_tmr0_ctrl, ctrl); + + ctrl.op = regk_timer_run; + REG_WR(timer, timer_base, rw_tmr0_ctrl, ctrl); + + return 0; +} - /* Update statistics. */ - update_process_times(user_mode(regs)); +static irqreturn_t crisv32_timer_interrupt(int irq, void *dev_id) +{ + struct clock_event_device *evt = dev_id; + reg_timer_rw_tmr0_ctrl ctrl = { + .op = regk_timer_hold, + .freq = regk_timer_f100, + }; + reg_timer_rw_ack_intr ack = { .tmr0 = 1 }; + reg_timer_r_masked_intr intr; + + intr = REG_RD(timer, timer_base, r_masked_intr); + if (!intr.tmr0) + return IRQ_NONE; + + REG_WR(timer, timer_base, rw_tmr0_ctrl, ctrl); + REG_WR(timer, timer_base, rw_ack_intr, ack); - cris_do_profile(regs); /* Save profiling information */ + reset_watchdog(); +#ifdef CONFIG_SYSTEM_PROFILER + cris_profile_sample(get_irq_regs()); +#endif - /* The master CPU is responsible for the time keeping. */ - if (cpu != 0) - return IRQ_HANDLED; + evt->event_handler(evt); - /* Call the real timer interrupt handler */ - xtime_update(1); return IRQ_HANDLED; } +static struct clock_event_device crisv32_clockevent = { + .name = "crisv32-timer", + .rating = 300, + .features = CLOCK_EVT_FEAT_ONESHOT, + .set_mode = crisv32_clkevt_mode, + .set_next_event = crisv32_clkevt_next_event, +}; + /* Timer is IRQF_SHARED so drivers can add stuff to the timer irq chain. */ static struct irqaction irq_timer = { - .handler = timer_interrupt, - .flags = IRQF_SHARED, - .name = "timer" + .handler = crisv32_timer_interrupt, + .flags = IRQF_TIMER | IRQF_SHARED, + .name = "crisv32-timer", + .dev_id = &crisv32_clockevent, }; -void __init cris_timer_init(void) +static void __init crisv32_timer_init(void) { - int cpu = smp_processor_id(); - reg_timer_rw_tmr0_ctrl tmr0_ctrl = { 0 }; - reg_timer_rw_tmr0_div tmr0_div = TIMER0_DIV; reg_timer_rw_intr_mask timer_intr_mask; + reg_timer_rw_tmr0_ctrl ctrl = { + .op = regk_timer_hold, + .freq = regk_timer_f100, + }; - /* Setup the etrax timers. - * Base frequency is 100MHz, divider 1000000 -> 100 HZ - * We use timer0, so timer1 is free. - * The trig timer is used by the fasttimer API if enabled. - */ - - tmr0_ctrl.op = regk_timer_ld; - tmr0_ctrl.freq = regk_timer_f100; - REG_WR(timer, timer_regs[cpu], rw_tmr0_div, tmr0_div); - REG_WR(timer, timer_regs[cpu], rw_tmr0_ctrl, tmr0_ctrl); /* Load */ - tmr0_ctrl.op = regk_timer_run; - REG_WR(timer, timer_regs[cpu], rw_tmr0_ctrl, tmr0_ctrl); /* Start */ + REG_WR(timer, timer_base, rw_tmr0_ctrl, ctrl); - /* Enable the timer irq. */ - timer_intr_mask = REG_RD(timer, timer_regs[cpu], rw_intr_mask); + timer_intr_mask = REG_RD(timer, timer_base, rw_intr_mask); timer_intr_mask.tmr0 = 1; - REG_WR(timer, timer_regs[cpu], rw_intr_mask, timer_intr_mask); + REG_WR(timer, timer_base, rw_intr_mask, timer_intr_mask); } void __init time_init(void) { - reg_intr_vect_rw_mask intr_mask; + int irq; + int ret; /* Probe for the RTC and read it if it exists. * Before the RTC can be probed the loops_per_usec variable needs @@ -270,17 +291,21 @@ void __init time_init(void) */ loops_per_usec = 50; - /* Start CPU local timer. */ - cris_timer_init(); + irq = TIMER0_INTR_VECT; + timer_base = (void __iomem *) regi_timer0; + + crisv32_timer_init(); + + crisv32_clockevent.cpumask = cpu_possible_mask; + crisv32_clockevent.irq = irq; - /* Enable the timer irq in global config. */ - intr_mask = REG_RD_VECT(intr_vect, regi_irq, rw_mask, 1); - intr_mask.timer0 = 1; - REG_WR_VECT(intr_vect, regi_irq, rw_mask, 1, intr_mask); + ret = setup_irq(irq, &irq_timer); + if (ret) + pr_warn("failed to setup irq %d\n", irq); - /* Now actually register the timer irq handler that calls - * timer_interrupt(). */ - setup_irq(TIMER0_INTR_VECT, &irq_timer); + clockevents_config_and_register(&crisv32_clockevent, + CRISV32_TIMER_FREQ, + 2, 0xffffffff); /* Enable watchdog if we should use one. */ |