From e09b41010ba33a20a87472ee821fa407a5b8da36 Mon Sep 17 00:00:00 2001 From: José Pekkarinen Date: Mon, 11 Apr 2016 10:41:07 +0300 Subject: These changes are the raw update to linux-4.4.6-rt14. Kernel sources are taken from kernel.org, and rt patch from the rt wiki download page. MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit During the rebasing, the following patch collided: Force tick interrupt and get rid of softirq magic(I70131fb85). Collisions have been removed because its logic was found on the source already. Change-Id: I7f57a4081d9deaa0d9ccfc41a6c8daccdee3b769 Signed-off-by: José Pekkarinen --- kernel/arch/mips/loongson32/common/time.c | 237 ++++++++++++++++++++++++++++++ 1 file changed, 237 insertions(+) create mode 100644 kernel/arch/mips/loongson32/common/time.c (limited to 'kernel/arch/mips/loongson32/common/time.c') diff --git a/kernel/arch/mips/loongson32/common/time.c b/kernel/arch/mips/loongson32/common/time.c new file mode 100644 index 000000000..0996b025e --- /dev/null +++ b/kernel/arch/mips/loongson32/common/time.c @@ -0,0 +1,237 @@ +/* + * Copyright (c) 2014 Zhang, Keguang + * + * This program is free software; you can redistribute it and/or modify it + * under the terms of the GNU General Public License as published by the + * Free Software Foundation; either version 2 of the License, or (at your + * option) any later version. + */ + +#include +#include +#include + +#include +#include + +#ifdef CONFIG_CEVT_CSRC_LS1X + +#if defined(CONFIG_TIMER_USE_PWM1) +#define LS1X_TIMER_BASE LS1X_PWM1_BASE +#define LS1X_TIMER_IRQ LS1X_PWM1_IRQ + +#elif defined(CONFIG_TIMER_USE_PWM2) +#define LS1X_TIMER_BASE LS1X_PWM2_BASE +#define LS1X_TIMER_IRQ LS1X_PWM2_IRQ + +#elif defined(CONFIG_TIMER_USE_PWM3) +#define LS1X_TIMER_BASE LS1X_PWM3_BASE +#define LS1X_TIMER_IRQ LS1X_PWM3_IRQ + +#else +#define LS1X_TIMER_BASE LS1X_PWM0_BASE +#define LS1X_TIMER_IRQ LS1X_PWM0_IRQ +#endif + +DEFINE_RAW_SPINLOCK(ls1x_timer_lock); + +static void __iomem *timer_base; +static uint32_t ls1x_jiffies_per_tick; + +static inline void ls1x_pwmtimer_set_period(uint32_t period) +{ + __raw_writel(period, timer_base + PWM_HRC); + __raw_writel(period, timer_base + PWM_LRC); +} + +static inline void ls1x_pwmtimer_restart(void) +{ + __raw_writel(0x0, timer_base + PWM_CNT); + __raw_writel(INT_EN | CNT_EN, timer_base + PWM_CTRL); +} + +void __init ls1x_pwmtimer_init(void) +{ + timer_base = ioremap(LS1X_TIMER_BASE, 0xf); + if (!timer_base) + panic("Failed to remap timer registers"); + + ls1x_jiffies_per_tick = DIV_ROUND_CLOSEST(mips_hpt_frequency, HZ); + + ls1x_pwmtimer_set_period(ls1x_jiffies_per_tick); + ls1x_pwmtimer_restart(); +} + +static cycle_t ls1x_clocksource_read(struct clocksource *cs) +{ + unsigned long flags; + int count; + u32 jifs; + static int old_count; + static u32 old_jifs; + + raw_spin_lock_irqsave(&ls1x_timer_lock, flags); + /* + * Although our caller may have the read side of xtime_lock, + * this is now a seqlock, and we are cheating in this routine + * by having side effects on state that we cannot undo if + * there is a collision on the seqlock and our caller has to + * retry. (Namely, old_jifs and old_count.) So we must treat + * jiffies as volatile despite the lock. We read jiffies + * before latching the timer count to guarantee that although + * the jiffies value might be older than the count (that is, + * the counter may underflow between the last point where + * jiffies was incremented and the point where we latch the + * count), it cannot be newer. + */ + jifs = jiffies; + /* read the count */ + count = __raw_readl(timer_base + PWM_CNT); + + /* + * It's possible for count to appear to go the wrong way for this + * reason: + * + * The timer counter underflows, but we haven't handled the resulting + * interrupt and incremented jiffies yet. + * + * Previous attempts to handle these cases intelligently were buggy, so + * we just do the simple thing now. + */ + if (count < old_count && jifs == old_jifs) + count = old_count; + + old_count = count; + old_jifs = jifs; + + raw_spin_unlock_irqrestore(&ls1x_timer_lock, flags); + + return (cycle_t) (jifs * ls1x_jiffies_per_tick) + count; +} + +static struct clocksource ls1x_clocksource = { + .name = "ls1x-pwmtimer", + .read = ls1x_clocksource_read, + .mask = CLOCKSOURCE_MASK(24), + .flags = CLOCK_SOURCE_IS_CONTINUOUS, +}; + +static irqreturn_t ls1x_clockevent_isr(int irq, void *devid) +{ + struct clock_event_device *cd = devid; + + ls1x_pwmtimer_restart(); + cd->event_handler(cd); + + return IRQ_HANDLED; +} + +static int ls1x_clockevent_set_state_periodic(struct clock_event_device *cd) +{ + raw_spin_lock(&ls1x_timer_lock); + ls1x_pwmtimer_set_period(ls1x_jiffies_per_tick); + ls1x_pwmtimer_restart(); + __raw_writel(INT_EN | CNT_EN, timer_base + PWM_CTRL); + raw_spin_unlock(&ls1x_timer_lock); + + return 0; +} + +static int ls1x_clockevent_tick_resume(struct clock_event_device *cd) +{ + raw_spin_lock(&ls1x_timer_lock); + __raw_writel(INT_EN | CNT_EN, timer_base + PWM_CTRL); + raw_spin_unlock(&ls1x_timer_lock); + + return 0; +} + +static int ls1x_clockevent_set_state_shutdown(struct clock_event_device *cd) +{ + raw_spin_lock(&ls1x_timer_lock); + __raw_writel(__raw_readl(timer_base + PWM_CTRL) & ~CNT_EN, + timer_base + PWM_CTRL); + raw_spin_unlock(&ls1x_timer_lock); + + return 0; +} + +static int ls1x_clockevent_set_next(unsigned long evt, + struct clock_event_device *cd) +{ + raw_spin_lock(&ls1x_timer_lock); + ls1x_pwmtimer_set_period(evt); + ls1x_pwmtimer_restart(); + raw_spin_unlock(&ls1x_timer_lock); + + return 0; +} + +static struct clock_event_device ls1x_clockevent = { + .name = "ls1x-pwmtimer", + .features = CLOCK_EVT_FEAT_PERIODIC, + .rating = 300, + .irq = LS1X_TIMER_IRQ, + .set_next_event = ls1x_clockevent_set_next, + .set_state_shutdown = ls1x_clockevent_set_state_shutdown, + .set_state_periodic = ls1x_clockevent_set_state_periodic, + .set_state_oneshot = ls1x_clockevent_set_state_shutdown, + .tick_resume = ls1x_clockevent_tick_resume, +}; + +static struct irqaction ls1x_pwmtimer_irqaction = { + .name = "ls1x-pwmtimer", + .handler = ls1x_clockevent_isr, + .dev_id = &ls1x_clockevent, + .flags = IRQF_PERCPU | IRQF_TIMER, +}; + +static void __init ls1x_time_init(void) +{ + struct clock_event_device *cd = &ls1x_clockevent; + int ret; + + if (!mips_hpt_frequency) + panic("Invalid timer clock rate"); + + ls1x_pwmtimer_init(); + + clockevent_set_clock(cd, mips_hpt_frequency); + cd->max_delta_ns = clockevent_delta2ns(0xffffff, cd); + cd->min_delta_ns = clockevent_delta2ns(0x000300, cd); + cd->cpumask = cpumask_of(smp_processor_id()); + clockevents_register_device(cd); + + ls1x_clocksource.rating = 200 + mips_hpt_frequency / 10000000; + ret = clocksource_register_hz(&ls1x_clocksource, mips_hpt_frequency); + if (ret) + panic(KERN_ERR "Failed to register clocksource: %d\n", ret); + + setup_irq(LS1X_TIMER_IRQ, &ls1x_pwmtimer_irqaction); +} +#endif /* CONFIG_CEVT_CSRC_LS1X */ + +void __init plat_time_init(void) +{ + struct clk *clk = NULL; + + /* initialize LS1X clocks */ + ls1x_clk_init(); + +#ifdef CONFIG_CEVT_CSRC_LS1X + /* setup LS1X PWM timer */ + clk = clk_get(NULL, "ls1x_pwmtimer"); + if (IS_ERR(clk)) + panic("unable to get timer clock, err=%ld", PTR_ERR(clk)); + + mips_hpt_frequency = clk_get_rate(clk); + ls1x_time_init(); +#else + /* setup mips r4k timer */ + clk = clk_get(NULL, "cpu_clk"); + if (IS_ERR(clk)) + panic("unable to get cpu clock, err=%ld", PTR_ERR(clk)); + + mips_hpt_frequency = clk_get_rate(clk) / 2; +#endif /* CONFIG_CEVT_CSRC_LS1X */ +} -- cgit 1.2.3-korg