// SPDX-License-Identifier: GPL-2.0-only /* linux/arch/arm/mach-exynos4/mct.c * * Copyright (c) 2011 Samsung Electronics Co., Ltd. * http://www.samsung.com * * Exynos4 MCT(Multi-Core Timer) support */ #include #include #include #include #include #include #include #include #include #include #include #include #include #define EXYNOS4_MCTREG(x) (x) #define EXYNOS4_MCT_G_CNT_L EXYNOS4_MCTREG(0x100) #define EXYNOS4_MCT_G_CNT_U EXYNOS4_MCTREG(0x104) #define EXYNOS4_MCT_G_CNT_WSTAT EXYNOS4_MCTREG(0x110) #define EXYNOS4_MCT_G_COMP0_L EXYNOS4_MCTREG(0x200) #define EXYNOS4_MCT_G_COMP0_U EXYNOS4_MCTREG(0x204) #define EXYNOS4_MCT_G_COMP0_ADD_INCR EXYNOS4_MCTREG(0x208) #define EXYNOS4_MCT_G_TCON EXYNOS4_MCTREG(0x240) #define EXYNOS4_MCT_G_INT_CSTAT EXYNOS4_MCTREG(0x244) #define EXYNOS4_MCT_G_INT_ENB EXYNOS4_MCTREG(0x248) #define EXYNOS4_MCT_G_WSTAT EXYNOS4_MCTREG(0x24C) #define _EXYNOS4_MCT_L_BASE EXYNOS4_MCTREG(0x300) #define EXYNOS4_MCT_L_BASE(x) (_EXYNOS4_MCT_L_BASE + (0x100 * (x))) #define EXYNOS4_MCT_L_MASK (0xffffff00) #define MCT_L_TCNTB_OFFSET (0x00) #define MCT_L_ICNTB_OFFSET (0x08) #define MCT_L_TCON_OFFSET (0x20) #define MCT_L_INT_CSTAT_OFFSET (0x30) #define MCT_L_INT_ENB_OFFSET (0x34) #define MCT_L_WSTAT_OFFSET (0x40) #define MCT_G_TCON_START (1 << 8) #define MCT_G_TCON_COMP0_AUTO_INC (1 << 1) #define MCT_G_TCON_COMP0_ENABLE (1 << 0) #define MCT_L_TCON_INTERVAL_MODE (1 << 2) #define MCT_L_TCON_INT_START (1 << 1) #define MCT_L_TCON_TIMER_START (1 << 0) #define TICK_BASE_CNT 1 #ifdef CONFIG_ARM /* Use values higher than ARM arch timer. See 6282edb72bed. */ #define MCT_CLKSOURCE_RATING 450 #define MCT_CLKEVENTS_RATING 500 #else #define MCT_CLKSOURCE_RATING 350 #define MCT_CLKEVENTS_RATING 350 #endif /* There are four Global timers starting with 0 offset */ #define MCT_G0_IRQ 0 /* Local timers count starts after global timer count */ #define MCT_L0_IRQ 4 /* Max number of IRQ as per DT binding document */ #define MCT_NR_IRQS 20 /* Max number of local timers */ #define MCT_NR_LOCAL (MCT_NR_IRQS - MCT_L0_IRQ) enum { MCT_INT_SPI, MCT_INT_PPI }; static void __iomem *reg_base; static unsigned long clk_rate; static unsigned int mct_int_type; static int mct_irqs[MCT_NR_IRQS]; struct mct_clock_event_device { struct clock_event_device evt; unsigned long base; /** * The length of the name must be adjusted if number of * local timer interrupts grow over two digits */ char name[11]; }; static void exynos4_mct_write(unsigned int value, unsigned long offset) { unsigned long stat_addr; u32 mask; u32 i; writel_relaxed(value, reg_base + offset); if (likely(offset >= EXYNOS4_MCT_L_BASE(0))) { stat_addr = (offset & EXYNOS4_MCT_L_MASK) + MCT_L_WSTAT_OFFSET; switch (offset & ~EXYNOS4_MCT_L_MASK) { case MCT_L_TCON_OFFSET: mask = 1 << 3; /* L_TCON write status */ break; case MCT_L_ICNTB_OFFSET: mask = 1 << 1; /* L_ICNTB write status */ break; case MCT_L_TCNTB_OFFSET: mask = 1 << 0; /* L_TCNTB write status */ break; default: return; } } else { switch (offset) { case EXYNOS4_MCT_G_TCON: stat_addr = EXYNOS4_MCT_G_WSTAT; mask = 1 << 16; /* G_TCON write status */ break; case EXYNOS4_MCT_G_COMP0_L: stat_addr = EXYNOS4_MCT_G_WSTAT; mask = 1 << 0; /* G_COMP0_L write status */ break; case EXYNOS4_MCT_G_COMP0_U: stat_addr = EXYNOS4_MCT_G_WSTAT; mask = 1 << 1; /* G_COMP0_U write status */ break; case EXYNOS4_MCT_G_COMP0_ADD_INCR: stat_addr = EXYNOS4_MCT_G_WSTAT; mask = 1 << 2; /* G_COMP0_ADD_INCR w status */ break; case EXYNOS4_MCT_G_CNT_L: stat_addr = EXYNOS4_MCT_G_CNT_WSTAT; mask = 1 << 0; /* G_CNT_L write status */ break; case 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 (readl_relaxed(reg_base + stat_addr) & mask) { writel_relaxed(mask, reg_base + stat_addr); return; } panic("MCT hangs after writing %d (offset:0x%lx)\n", value, offset); } /* Clocksource handling */ static void exynos4_mct_frc_start(void) { u32 reg; reg = readl_relaxed(reg_base + EXYNOS4_MCT_G_TCON); reg |= MCT_G_TCON_START; exynos4_mct_write(reg, EXYNOS4_MCT_G_TCON); } /** * exynos4_read_count_64 - Read all 64-bits of the global counter * * This will read all 64-bits of the global counter taking care to make sure * that the upper and lower half match. Note that reading the MCT can be quite * slow (hundreds of nanoseconds) so you should use the 32-bit (lower half * only) version when possible. * * Returns the number of cycles in the global counter. */ static u64 exynos4_read_count_64(void) { unsigned int lo, hi; u32 hi2 = readl_relaxed(reg_base + EXYNOS4_MCT_G_CNT_U); do { hi = hi2; lo = readl_relaxed(reg_base + EXYNOS4_MCT_G_CNT_L); hi2 = readl_relaxed(reg_base + EXYNOS4_MCT_G_CNT_U); } while (hi != hi2); return ((u64)hi << 32) | lo; } /** * exynos4_read_count_32 - Read the lower 32-bits of the global counter * * This will read just the lower 32-bits of the global counter. This is marked * as notrace so it can be used by the scheduler clock. * * Returns the number of cycles in the global counter (lower 32 bits). */ static u32 notrace exynos4_read_count_32(void) { return readl_relaxed(reg_base + EXYNOS4_MCT_G_CNT_L); } static u64 exynos4_frc_read(struct clocksource *cs) { return exynos4_read_count_32(); } static void exynos4_frc_resume(struct clocksource *cs) { exynos4_mct_frc_start(); } static struct clocksource mct_frc = { .name = "mct-frc", .rating = MCT_CLKSOURCE_RATING, .read = exynos4_frc_read, .mask = CLOCKSOURCE_MASK(32), .flags = CLOCK_SOURCE_IS_CONTINUOUS, .resume = exynos4_frc_resume, }; static u64 notrace exynos4_read_sched_clock(void) { return exynos4_read_count_32(); } #if defined(CONFIG_ARM) static struct delay_timer exynos4_delay_timer; static cycles_t exynos4_read_current_timer(void) { BUILD_BUG_ON_MSG(sizeof(cycles_t) != sizeof(u32), "cycles_t needs to move to 32-bit for ARM64 usage"); return exynos4_read_count_32(); } #endif static int __init exynos4_clocksource_init(bool frc_shared) { /* * When the frc is shared, the main processer should have already * turned it on and we shouldn't be writing to TCON. */ if (frc_shared) mct_frc.resume = NULL; else exynos4_mct_frc_start(); #if defined(CONFIG_ARM) exynos4_delay_timer.read_current_timer = &exynos4_read_current_timer; exynos4_delay_timer.freq = clk_rate; register_current_timer_delay(&exynos4_delay_timer); #endif if (clocksource_register_hz(&mct_frc, clk_rate)) panic("%s: can't register clocksource\n", mct_frc.name); sched_clock_register(exynos4_read_sched_clock, 32, clk_rate); return 0; } static void exynos4_mct_comp0_stop(void) { unsigned int tcon; tcon = readl_relaxed(reg_base + 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(bool periodic, unsigned long cycles) { unsigned int tcon; u64 comp_cycle; tcon = readl_relaxed(reg_base + EXYNOS4_MCT_G_TCON); if (periodic) { tcon |= MCT_G_TCON_COMP0_AUTO_INC; exynos4_mct_write(cycles, EXYNOS4_MCT_G_COMP0_ADD_INCR); } comp_cycle = exynos4_read_count_64() + 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(false, cycles); return 0; } static int mct_set_state_shutdown(struct clock_event_device *evt) { exynos4_mct_comp0_stop(); return 0; } static int mct_set_state_periodic(struct clock_event_device *evt) { unsigned long cycles_per_jiffy; cycles_per_jiffy = (((unsigned long long)NSEC_PER_SEC / HZ * evt->mult) >> evt->shift); exynos4_mct_comp0_stop(); exynos4_mct_comp0_start(true, cycles_per_jiffy); return 0; } 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_state_periodic = mct_set_state_periodic, .set_state_shutdown = mct_set_state_shutdown, .set_state_oneshot = mct_set_state_shutdown, .set_state_oneshot_stopped = mct_set_state_shutdown, .tick_resume = mct_set_state_shutdown, }; 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 int exynos4_clockevent_init(void) { mct_comp_device.cpumask = cpumask_of(0); clockevents_config_and_register(&mct_comp_device, clk_rate, 0xf, 0xffffffff); if (request_irq(mct_irqs[MCT_G0_IRQ], exynos4_mct_comp_isr, IRQF_TIMER | IRQF_IRQPOLL, "mct_comp_irq", &mct_comp_device)) pr_err("%s: request_irq() failed\n", "mct_comp_irq"); return 0; } static DEFINE_PER_CPU(struct mct_clock_event_device, percpu_mct_tick); /* 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; unsigned long offset = mevt->base + MCT_L_TCON_OFFSET; tmp = readl_relaxed(reg_base + offset); if (tmp & mask) { tmp &= ~mask; exynos4_mct_write(tmp, offset); } } 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 = readl_relaxed(reg_base + 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 void exynos4_mct_tick_clear(struct mct_clock_event_device *mevt) { /* Clear the MCT tick interrupt */ if (readl_relaxed(reg_base + mevt->base + MCT_L_INT_CSTAT_OFFSET) & 1) exynos4_mct_write(0x1, mevt->base + MCT_L_INT_CSTAT_OFFSET); } static int exynos4_tick_set_next_event(unsigned long cycles, struct clock_event_device *evt) { struct mct_clock_event_device *mevt; mevt = container_of(evt, struct mct_clock_event_device, evt); exynos4_mct_tick_start(cycles, mevt); return 0; } static int set_state_shutdown(struct clock_event_device *evt) { struct mct_clock_event_device *mevt; mevt = container_of(evt, struct mct_clock_event_device, evt); exynos4_mct_tick_stop(mevt); exynos4_mct_tick_clear(mevt); return 0; } static int set_state_periodic(struct clock_event_device *evt) { struct mct_clock_event_device *mevt; unsigned long cycles_per_jiffy; mevt = container_of(evt, struct mct_clock_event_device, evt); cycles_per_jiffy = (((unsigned long long)NSEC_PER_SEC / HZ * evt->mult) >> evt->shift); exynos4_mct_tick_stop(mevt); exynos4_mct_tick_start(cycles_per_jiffy, mevt); 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; /* * This is for supporting oneshot mode. * Mct would generate interrupt periodically * without explicit stopping. */ if (!clockevent_state_periodic(&mevt->evt)) exynos4_mct_tick_stop(mevt); exynos4_mct_tick_clear(mevt); evt->event_handler(evt); return IRQ_HANDLED; } static int exynos4_mct_starting_cpu(unsigned int cpu) { struct mct_clock_event_device *mevt = per_cpu_ptr(&percpu_mct_tick, cpu); struct clock_event_device *evt = &mevt->evt; snprintf(mevt->name, sizeof(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_state_periodic = set_state_periodic; evt->set_state_shutdown = set_state_shutdown; evt->set_state_oneshot = set_state_shutdown; evt->set_state_oneshot_stopped = set_state_shutdown; evt->tick_resume = set_state_shutdown; evt->features = CLOCK_EVT_FEAT_PERIODIC | CLOCK_EVT_FEAT_ONESHOT | CLOCK_EVT_FEAT_PERCPU; evt->rating = MCT_CLKEVENTS_RATING; exynos4_mct_write(TICK_BASE_CNT, mevt->base + MCT_L_TCNTB_OFFSET); if (mct_int_type == MCT_INT_SPI) { if (evt->irq == -1) return -EIO; irq_force_affinity(evt->irq, cpumask_of(cpu)); enable_irq(evt->irq); } else { enable_percpu_irq(mct_irqs[MCT_L0_IRQ], 0); } clockevents_config_and_register(evt, clk_rate / (TICK_BASE_CNT + 1), 0xf, 0x7fffffff); return 0; } static int exynos4_mct_dying_cpu(unsigned int cpu) { struct mct_clock_event_device *mevt = per_cpu_ptr(&percpu_mct_tick, cpu); struct clock_event_device *evt = &mevt->evt; evt->set_state_shutdown(evt); if (mct_int_type == MCT_INT_SPI) { if (evt->irq != -1) disable_irq_nosync(evt->irq); exynos4_mct_write(0x1, mevt->base + MCT_L_INT_CSTAT_OFFSET); } else { disable_percpu_irq(mct_irqs[MCT_L0_IRQ]); } return 0; } static int __init exynos4_timer_resources(struct device_node *np) { struct clk *mct_clk, *tick_clk; reg_base = of_iomap(np, 0); if (!reg_base) panic("%s: unable to ioremap mct address space\n", __func__); tick_clk = of_clk_get_by_name(np, "fin_pll"); if (IS_ERR(tick_clk)) panic("%s: unable to determine tick clock rate\n", __func__); clk_rate = clk_get_rate(tick_clk); mct_clk = of_clk_get_by_name(np, "mct"); if (IS_ERR(mct_clk)) panic("%s: unable to retrieve mct clock instance\n", __func__); clk_prepare_enable(mct_clk); return 0; } /** * exynos4_timer_interrupts - initialize MCT interrupts * @np: device node for MCT * @int_type: interrupt type, MCT_INT_PPI or MCT_INT_SPI * @local_idx: array mapping CPU numbers to local timer indices * @nr_local: size of @local_idx array */ static int __init exynos4_timer_interrupts(struct device_node *np, unsigned int int_type, const u32 *local_idx, size_t nr_local) { int nr_irqs, i, err, cpu; mct_int_type = int_type; /* This driver uses only one global timer interrupt */ mct_irqs[MCT_G0_IRQ] = irq_of_parse_and_map(np, MCT_G0_IRQ); /* * Find out the number of local irqs specified. The local * timer irqs are specified after the four global timer * irqs are specified. */ nr_irqs = of_irq_count(np); if (nr_irqs > ARRAY_SIZE(mct_irqs)) { pr_err("exynos-mct: too many (%d) interrupts configured in DT\n", nr_irqs); nr_irqs = ARRAY_SIZE(mct_irqs); } for (i = MCT_L0_IRQ; i < nr_irqs; i++) mct_irqs[i] = irq_of_parse_and_map(np, i); if (mct_int_type == MCT_INT_PPI) { err = request_percpu_irq(mct_irqs[MCT_L0_IRQ], exynos4_mct_tick_isr, "MCT", &percpu_mct_tick); WARN(err, "MCT: can't request IRQ %d (%d)\n", mct_irqs[MCT_L0_IRQ], err); } else { for_each_possible_cpu(cpu) { int mct_irq; unsigned int irq_idx; struct mct_clock_event_device *pcpu_mevt = per_cpu_ptr(&percpu_mct_tick, cpu); if (cpu >= nr_local) { err = -EINVAL; goto out_irq; } irq_idx = MCT_L0_IRQ + local_idx[cpu]; pcpu_mevt->evt.irq = -1; if (irq_idx >= ARRAY_SIZE(mct_irqs)) break; mct_irq = mct_irqs[irq_idx]; irq_set_status_flags(mct_irq, IRQ_NOAUTOEN); if (request_irq(mct_irq, exynos4_mct_tick_isr, IRQF_TIMER | IRQF_NOBALANCING, pcpu_mevt->name, pcpu_mevt)) { pr_err("exynos-mct: cannot register IRQ (cpu%d)\n", cpu); continue; } pcpu_mevt->evt.irq = mct_irq; } } for_each_possible_cpu(cpu) { struct mct_clock_event_device *mevt = per_cpu_ptr(&percpu_mct_tick, cpu); if (cpu >= nr_local) { err = -EINVAL; goto out_irq; } mevt->base = EXYNOS4_MCT_L_BASE(local_idx[cpu]); } /* Install hotplug callbacks which configure the timer on this CPU */ err = cpuhp_setup_state(CPUHP_AP_EXYNOS4_MCT_TIMER_STARTING, "clockevents/exynos4/mct_timer:starting", exynos4_mct_starting_cpu, exynos4_mct_dying_cpu); if (err) goto out_irq; return 0; out_irq: if (mct_int_type == MCT_INT_PPI) { free_percpu_irq(mct_irqs[MCT_L0_IRQ], &percpu_mct_tick); } else { for_each_possible_cpu(cpu) { struct mct_clock_event_device *pcpu_mevt = per_cpu_ptr(&percpu_mct_tick, cpu); if (pcpu_mevt->evt.irq != -1) { free_irq(pcpu_mevt->evt.irq, pcpu_mevt); pcpu_mevt->evt.irq = -1; } } } return err; } static int __init mct_init_dt(struct device_node *np, unsigned int int_type) { bool frc_shared = of_property_read_bool(np, "samsung,frc-shared"); u32 local_idx[MCT_NR_LOCAL] = {0}; int nr_local; int ret; nr_local = of_property_count_u32_elems(np, "samsung,local-timers"); if (nr_local == 0) return -EINVAL; if (nr_local > 0) { if (nr_local > ARRAY_SIZE(local_idx)) return -EINVAL; ret = of_property_read_u32_array(np, "samsung,local-timers", local_idx, nr_local); if (ret) return ret; } else { int i; nr_local = ARRAY_SIZE(local_idx); for (i = 0; i < nr_local; i++) local_idx[i] = i; } ret = exynos4_timer_resources(np); if (ret) return ret; ret = exynos4_timer_interrupts(np, int_type, local_idx, nr_local); if (ret) return ret; ret = exynos4_clocksource_init(frc_shared); if (ret) return ret; /* * When the FRC is shared with a main processor, this secondary * processor cannot use the global comparator. */ if (frc_shared) return ret; return exynos4_clockevent_init(); } static int __init mct_init_spi(struct device_node *np) { return mct_init_dt(np, MCT_INT_SPI); } static int __init mct_init_ppi(struct device_node *np) { return mct_init_dt(np, MCT_INT_PPI); } TIMER_OF_DECLARE(exynos4210, "samsung,exynos4210-mct", mct_init_spi); TIMER_OF_DECLARE(exynos4412, "samsung,exynos4412-mct", mct_init_ppi);