diff options
Diffstat (limited to 'arch/arm/mach-exynos/mct.c')
| -rw-r--r-- | arch/arm/mach-exynos/mct.c | 471 |
1 files changed, 471 insertions, 0 deletions
diff --git a/arch/arm/mach-exynos/mct.c b/arch/arm/mach-exynos/mct.c new file mode 100644 index 000000000000..97343df8f132 --- /dev/null +++ b/arch/arm/mach-exynos/mct.c @@ -0,0 +1,471 @@ +/* linux/arch/arm/mach-exynos4/mct.c + * + * Copyright (c) 2011 Samsung Electronics Co., Ltd. + * http://www.samsung.com + * + * EXYNOS4 MCT(Multi-Core Timer) support + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. +*/ + +#include <linux/sched.h> +#include <linux/interrupt.h> +#include <linux/irq.h> +#include <linux/err.h> +#include <linux/clk.h> +#include <linux/clockchips.h> +#include <linux/platform_device.h> +#include <linux/delay.h> +#include <linux/percpu.h> + +#include <asm/hardware/gic.h> + +#include <plat/cpu.h> + +#include <mach/map.h> +#include <mach/irqs.h> +#include <mach/regs-mct.h> +#include <asm/mach/time.h> + +enum { + MCT_INT_SPI, + MCT_INT_PPI +}; + +static unsigned long clk_cnt_per_tick; +static unsigned long clk_rate; +static unsigned int mct_int_type; + +struct mct_clock_event_device { + struct clock_event_device *evt; + void __iomem *base; + char name[10]; +}; + +static DEFINE_PER_CPU(struct mct_clock_event_device, percpu_mct_tick); + +static void exynos4_mct_write(unsigned int value, void *addr) +{ + void __iomem *stat_addr; + u32 mask; + u32 i; + + __raw_writel(value, addr); + + if (likely(addr >= EXYNOS4_MCT_L_BASE(0))) { + u32 base = (u32) addr & EXYNOS4_MCT_L_MASK; + switch ((u32) addr & ~EXYNOS4_MCT_L_MASK) { + case (u32) MCT_L_TCON_OFFSET: + stat_addr = (void __iomem *) base + MCT_L_WSTAT_OFFSET; + mask = 1 << 3; /* L_TCON write status */ + break; + case (u32) MCT_L_ICNTB_OFFSET: + stat_addr = (void __iomem *) base + MCT_L_WSTAT_OFFSET; + mask = 1 << 1; /* L_ICNTB write status */ + break; + case (u32) MCT_L_TCNTB_OFFSET: + stat_addr = (void __iomem *) base + MCT_L_WSTAT_OFFSET; + mask = 1 << 0; /* L_TCNTB write status */ + break; + default: + return; + } + } else { + switch ((u32) addr) { + case (u32) EXYNOS4_MCT_G_TCON: + stat_addr = EXYNOS4_MCT_G_WSTAT; + mask = 1 << 16; /* G_TCON write status */ + break; + case (u32) EXYNOS4_MCT_G_COMP0_L: + stat_addr = EXYNOS4_MCT_G_WSTAT; + mask = 1 << 0; /* G_COMP0_L write status */ + break; + case (u32) EXYNOS4_MCT_G_COMP0_U: + stat_addr = EXYNOS4_MCT_G_WSTAT; + mask = 1 << 1; /* G_COMP0_U write status */ + break; + case (u32) EXYNOS4_MCT_G_COMP0_ADD_INCR: + stat_addr = EXYNOS4_MCT_G_WSTAT; + mask = 1 << 2; /* G_COMP0_ADD_INCR w status */ + break; + case (u32) EXYNOS4_MCT_G_CNT_L: + stat_addr = EXYNOS4_MCT_G_CNT_WSTAT; + mask = 1 << 0; /* G_CNT_L write status */ + break; + case (u32) EXYNOS4_MCT_G_CNT_U: + stat_addr = EXYNOS4_MCT_G_CNT_WSTAT; + mask = 1 << 1; /* G_CNT_U write status */ + break; + default: + return; + } + } + + /* Wait maximum 1 ms until written values are applied */ + for (i = 0; i < loops_per_jiffy / 1000 * HZ; i++) + if (__raw_readl(stat_addr) & mask) { + __raw_writel(mask, stat_addr); + return; + } + + panic("MCT hangs after writing %d (addr:0x%08x)\n", value, (u32)addr); +} + +/* Clocksource handling */ +static void exynos4_mct_frc_start(u32 hi, u32 lo) +{ + u32 reg; + + exynos4_mct_write(lo, EXYNOS4_MCT_G_CNT_L); + exynos4_mct_write(hi, EXYNOS4_MCT_G_CNT_U); + + reg = __raw_readl(EXYNOS4_MCT_G_TCON); + reg |= MCT_G_TCON_START; + exynos4_mct_write(reg, EXYNOS4_MCT_G_TCON); +} + +static cycle_t exynos4_frc_read(struct clocksource *cs) +{ + unsigned int lo, hi; + u32 hi2 = __raw_readl(EXYNOS4_MCT_G_CNT_U); + + do { + hi = hi2; + lo = __raw_readl(EXYNOS4_MCT_G_CNT_L); + hi2 = __raw_readl(EXYNOS4_MCT_G_CNT_U); + } while (hi != hi2); + + return ((cycle_t)hi << 32) | lo; +} + +static void exynos4_frc_resume(struct clocksource *cs) +{ + exynos4_mct_frc_start(0, 0); +} + +struct clocksource mct_frc = { + .name = "mct-frc", + .rating = 400, + .read = exynos4_frc_read, + .mask = CLOCKSOURCE_MASK(64), + .flags = CLOCK_SOURCE_IS_CONTINUOUS, + .resume = exynos4_frc_resume, +}; + +static void __init exynos4_clocksource_init(void) +{ + exynos4_mct_frc_start(0, 0); + + if (clocksource_register_hz(&mct_frc, clk_rate)) + panic("%s: can't register clocksource\n", mct_frc.name); +} + +static void exynos4_mct_comp0_stop(void) +{ + unsigned int tcon; + + tcon = __raw_readl(EXYNOS4_MCT_G_TCON); + tcon &= ~(MCT_G_TCON_COMP0_ENABLE | MCT_G_TCON_COMP0_AUTO_INC); + + exynos4_mct_write(tcon, EXYNOS4_MCT_G_TCON); + exynos4_mct_write(0, EXYNOS4_MCT_G_INT_ENB); +} + +static void exynos4_mct_comp0_start(enum clock_event_mode mode, + unsigned long cycles) +{ + unsigned int tcon; + cycle_t comp_cycle; + + tcon = __raw_readl(EXYNOS4_MCT_G_TCON); + + if (mode == CLOCK_EVT_MODE_PERIODIC) { + tcon |= MCT_G_TCON_COMP0_AUTO_INC; + exynos4_mct_write(cycles, EXYNOS4_MCT_G_COMP0_ADD_INCR); + } + + comp_cycle = exynos4_frc_read(&mct_frc) + cycles; + exynos4_mct_write((u32)comp_cycle, EXYNOS4_MCT_G_COMP0_L); + exynos4_mct_write((u32)(comp_cycle >> 32), EXYNOS4_MCT_G_COMP0_U); + + exynos4_mct_write(0x1, EXYNOS4_MCT_G_INT_ENB); + + tcon |= MCT_G_TCON_COMP0_ENABLE; + exynos4_mct_write(tcon , EXYNOS4_MCT_G_TCON); +} + +static int exynos4_comp_set_next_event(unsigned long cycles, + struct clock_event_device *evt) +{ + exynos4_mct_comp0_start(evt->mode, cycles); + + return 0; +} + +static void exynos4_comp_set_mode(enum clock_event_mode mode, + struct clock_event_device *evt) +{ + exynos4_mct_comp0_stop(); + + switch (mode) { + case CLOCK_EVT_MODE_PERIODIC: + exynos4_mct_comp0_start(mode, clk_cnt_per_tick); + break; + + case CLOCK_EVT_MODE_ONESHOT: + case CLOCK_EVT_MODE_UNUSED: + case CLOCK_EVT_MODE_SHUTDOWN: + case CLOCK_EVT_MODE_RESUME: + break; + } +} + +static struct clock_event_device mct_comp_device = { + .name = "mct-comp", + .features = CLOCK_EVT_FEAT_PERIODIC | CLOCK_EVT_FEAT_ONESHOT, + .rating = 250, + .set_next_event = exynos4_comp_set_next_event, + .set_mode = exynos4_comp_set_mode, +}; + +static irqreturn_t exynos4_mct_comp_isr(int irq, void *dev_id) +{ + struct clock_event_device *evt = dev_id; + + exynos4_mct_write(0x1, EXYNOS4_MCT_G_INT_CSTAT); + + evt->event_handler(evt); + + return IRQ_HANDLED; +} + +static struct irqaction mct_comp_event_irq = { + .name = "mct_comp_irq", + .flags = IRQF_TIMER | IRQF_IRQPOLL, + .handler = exynos4_mct_comp_isr, + .dev_id = &mct_comp_device, +}; + +static void exynos4_clockevent_init(void) +{ + clk_cnt_per_tick = clk_rate / 2 / HZ; + + clockevents_calc_mult_shift(&mct_comp_device, clk_rate / 2, 5); + mct_comp_device.max_delta_ns = + clockevent_delta2ns(0xffffffff, &mct_comp_device); + mct_comp_device.min_delta_ns = + clockevent_delta2ns(0xf, &mct_comp_device); + mct_comp_device.cpumask = cpumask_of(0); + clockevents_register_device(&mct_comp_device); + + setup_irq(IRQ_MCT_G0, &mct_comp_event_irq); +} + +#ifdef CONFIG_LOCAL_TIMERS +/* Clock event handling */ +static void exynos4_mct_tick_stop(struct mct_clock_event_device *mevt) +{ + unsigned long tmp; + unsigned long mask = MCT_L_TCON_INT_START | MCT_L_TCON_TIMER_START; + void __iomem *addr = mevt->base + MCT_L_TCON_OFFSET; + + tmp = __raw_readl(addr); + if (tmp & mask) { + tmp &= ~mask; + exynos4_mct_write(tmp, addr); + } +} + +static void exynos4_mct_tick_start(unsigned long cycles, + struct mct_clock_event_device *mevt) +{ + unsigned long tmp; + + exynos4_mct_tick_stop(mevt); + + tmp = (1 << 31) | cycles; /* MCT_L_UPDATE_ICNTB */ + + /* update interrupt count buffer */ + exynos4_mct_write(tmp, mevt->base + MCT_L_ICNTB_OFFSET); + + /* enable MCT tick interrupt */ + exynos4_mct_write(0x1, mevt->base + MCT_L_INT_ENB_OFFSET); + + tmp = __raw_readl(mevt->base + MCT_L_TCON_OFFSET); + tmp |= MCT_L_TCON_INT_START | MCT_L_TCON_TIMER_START | + MCT_L_TCON_INTERVAL_MODE; + exynos4_mct_write(tmp, mevt->base + MCT_L_TCON_OFFSET); +} + +static int exynos4_tick_set_next_event(unsigned long cycles, + struct clock_event_device *evt) +{ + struct mct_clock_event_device *mevt = this_cpu_ptr(&percpu_mct_tick); + + exynos4_mct_tick_start(cycles, mevt); + + return 0; +} + +static inline void exynos4_tick_set_mode(enum clock_event_mode mode, + struct clock_event_device *evt) +{ + struct mct_clock_event_device *mevt = this_cpu_ptr(&percpu_mct_tick); + + exynos4_mct_tick_stop(mevt); + + switch (mode) { + case CLOCK_EVT_MODE_PERIODIC: + exynos4_mct_tick_start(clk_cnt_per_tick, mevt); + break; + + case CLOCK_EVT_MODE_ONESHOT: + case CLOCK_EVT_MODE_UNUSED: + case CLOCK_EVT_MODE_SHUTDOWN: + case CLOCK_EVT_MODE_RESUME: + break; + } +} + +static int exynos4_mct_tick_clear(struct mct_clock_event_device *mevt) +{ + struct clock_event_device *evt = mevt->evt; + + /* + * This is for supporting oneshot mode. + * Mct would generate interrupt periodically + * without explicit stopping. + */ + if (evt->mode != CLOCK_EVT_MODE_PERIODIC) + exynos4_mct_tick_stop(mevt); + + /* Clear the MCT tick interrupt */ + if (__raw_readl(mevt->base + MCT_L_INT_CSTAT_OFFSET) & 1) { + exynos4_mct_write(0x1, mevt->base + MCT_L_INT_CSTAT_OFFSET); + return 1; + } else { + return 0; + } +} + +static irqreturn_t exynos4_mct_tick_isr(int irq, void *dev_id) +{ + struct mct_clock_event_device *mevt = dev_id; + struct clock_event_device *evt = mevt->evt; + + exynos4_mct_tick_clear(mevt); + + evt->event_handler(evt); + + return IRQ_HANDLED; +} + +static struct irqaction mct_tick0_event_irq = { + .name = "mct_tick0_irq", + .flags = IRQF_TIMER | IRQF_NOBALANCING, + .handler = exynos4_mct_tick_isr, +}; + +static struct irqaction mct_tick1_event_irq = { + .name = "mct_tick1_irq", + .flags = IRQF_TIMER | IRQF_NOBALANCING, + .handler = exynos4_mct_tick_isr, +}; + +static void exynos4_mct_tick_init(struct clock_event_device *evt) +{ + struct mct_clock_event_device *mevt; + unsigned int cpu = smp_processor_id(); + + mevt = this_cpu_ptr(&percpu_mct_tick); + mevt->evt = evt; + + mevt->base = EXYNOS4_MCT_L_BASE(cpu); + sprintf(mevt->name, "mct_tick%d", cpu); + + evt->name = mevt->name; + evt->cpumask = cpumask_of(cpu); + evt->set_next_event = exynos4_tick_set_next_event; + evt->set_mode = exynos4_tick_set_mode; + evt->features = CLOCK_EVT_FEAT_PERIODIC | CLOCK_EVT_FEAT_ONESHOT; + evt->rating = 450; + + clockevents_calc_mult_shift(evt, clk_rate / 2, 5); + evt->max_delta_ns = + clockevent_delta2ns(0x7fffffff, evt); + evt->min_delta_ns = + clockevent_delta2ns(0xf, evt); + + clockevents_register_device(evt); + + exynos4_mct_write(0x1, mevt->base + MCT_L_TCNTB_OFFSET); + + if (mct_int_type == MCT_INT_SPI) { + if (cpu == 0) { + mct_tick0_event_irq.dev_id = mevt; + evt->irq = IRQ_MCT_L0; + setup_irq(IRQ_MCT_L0, &mct_tick0_event_irq); + } else { + mct_tick1_event_irq.dev_id = mevt; + evt->irq = IRQ_MCT_L1; + setup_irq(IRQ_MCT_L1, &mct_tick1_event_irq); + irq_set_affinity(IRQ_MCT_L1, cpumask_of(1)); + } + } else { + enable_percpu_irq(IRQ_MCT_LOCALTIMER, 0); + } +} + +/* Setup the local clock events for a CPU */ +int __cpuinit local_timer_setup(struct clock_event_device *evt) +{ + exynos4_mct_tick_init(evt); + + return 0; +} + +void local_timer_stop(struct clock_event_device *evt) +{ + evt->set_mode(CLOCK_EVT_MODE_UNUSED, evt); + if (mct_int_type == MCT_INT_SPI) + disable_irq(evt->irq); + else + disable_percpu_irq(IRQ_MCT_LOCALTIMER); +} +#endif /* CONFIG_LOCAL_TIMERS */ + +static void __init exynos4_timer_resources(void) +{ + struct clk *mct_clk; + mct_clk = clk_get(NULL, "xtal"); + + clk_rate = clk_get_rate(mct_clk); + + if (mct_int_type == MCT_INT_PPI) { + int err; + + err = request_percpu_irq(IRQ_MCT_LOCALTIMER, + exynos4_mct_tick_isr, "MCT", + &percpu_mct_tick); + WARN(err, "MCT: can't request IRQ %d (%d)\n", + IRQ_MCT_LOCALTIMER, err); + } +} + +static void __init exynos4_timer_init(void) +{ + if (soc_is_exynos4210()) + mct_int_type = MCT_INT_SPI; + else + mct_int_type = MCT_INT_PPI; + + exynos4_timer_resources(); + exynos4_clocksource_init(); + exynos4_clockevent_init(); +} + +struct sys_timer exynos4_timer = { + .init = exynos4_timer_init, +}; |
