108dbd0f8SThomas Gleixner // SPDX-License-Identifier: GPL-2.0-only 271e4a47fSRichard Kuo /* 371e4a47fSRichard Kuo * Time related functions for Hexagon architecture 471e4a47fSRichard Kuo * 5e1858b2aSRichard Kuo * Copyright (c) 2010-2011, The Linux Foundation. All rights reserved. 671e4a47fSRichard Kuo */ 771e4a47fSRichard Kuo 871e4a47fSRichard Kuo #include <linux/init.h> 971e4a47fSRichard Kuo #include <linux/clockchips.h> 1071e4a47fSRichard Kuo #include <linux/clocksource.h> 1171e4a47fSRichard Kuo #include <linux/interrupt.h> 1271e4a47fSRichard Kuo #include <linux/err.h> 1371e4a47fSRichard Kuo #include <linux/platform_device.h> 1471e4a47fSRichard Kuo #include <linux/ioport.h> 1571e4a47fSRichard Kuo #include <linux/of.h> 1671e4a47fSRichard Kuo #include <linux/of_address.h> 1771e4a47fSRichard Kuo #include <linux/of_irq.h> 186bbbc30cSRichard Kuo #include <linux/module.h> 1971e4a47fSRichard Kuo 2071e4a47fSRichard Kuo #include <asm/timer-regs.h> 2171e4a47fSRichard Kuo #include <asm/hexagon_vm.h> 2271e4a47fSRichard Kuo 2371e4a47fSRichard Kuo /* 2471e4a47fSRichard Kuo * For the clocksource we need: 2571e4a47fSRichard Kuo * pcycle frequency (600MHz) 2671e4a47fSRichard Kuo * For the loops_per_jiffy we need: 2771e4a47fSRichard Kuo * thread/cpu frequency (100MHz) 2871e4a47fSRichard Kuo * And for the timer, we need: 2971e4a47fSRichard Kuo * sleep clock rate 3071e4a47fSRichard Kuo */ 3171e4a47fSRichard Kuo 3271e4a47fSRichard Kuo cycles_t pcycle_freq_mhz; 3371e4a47fSRichard Kuo cycles_t thread_freq_mhz; 3471e4a47fSRichard Kuo cycles_t sleep_clk_freq; 3571e4a47fSRichard Kuo 3671e4a47fSRichard Kuo static struct resource rtos_timer_resources[] = { 3771e4a47fSRichard Kuo { 3871e4a47fSRichard Kuo .start = RTOS_TIMER_REGS_ADDR, 3971e4a47fSRichard Kuo .end = RTOS_TIMER_REGS_ADDR+PAGE_SIZE-1, 4071e4a47fSRichard Kuo .flags = IORESOURCE_MEM, 4171e4a47fSRichard Kuo }, 4271e4a47fSRichard Kuo }; 4371e4a47fSRichard Kuo 4471e4a47fSRichard Kuo static struct platform_device rtos_timer_device = { 4571e4a47fSRichard Kuo .name = "rtos_timer", 4671e4a47fSRichard Kuo .id = -1, 4771e4a47fSRichard Kuo .num_resources = ARRAY_SIZE(rtos_timer_resources), 4871e4a47fSRichard Kuo .resource = rtos_timer_resources, 4971e4a47fSRichard Kuo }; 5071e4a47fSRichard Kuo 5171e4a47fSRichard Kuo /* A lot of this stuff should move into a platform specific section. */ 5271e4a47fSRichard Kuo struct adsp_hw_timer_struct { 5371e4a47fSRichard Kuo u32 match; /* Match value */ 5471e4a47fSRichard Kuo u32 count; 5571e4a47fSRichard Kuo u32 enable; /* [1] - CLR_ON_MATCH_EN, [0] - EN */ 5671e4a47fSRichard Kuo u32 clear; /* one-shot register that clears the count */ 5771e4a47fSRichard Kuo }; 5871e4a47fSRichard Kuo 5971e4a47fSRichard Kuo /* Look for "TCX0" for related constants. */ 6071e4a47fSRichard Kuo static __iomem struct adsp_hw_timer_struct *rtos_timer; 6171e4a47fSRichard Kuo 62a5a1d1c2SThomas Gleixner static u64 timer_get_cycles(struct clocksource *cs) 6371e4a47fSRichard Kuo { 64a5a1d1c2SThomas Gleixner return (u64) __vmgettime(); 6571e4a47fSRichard Kuo } 6671e4a47fSRichard Kuo 6771e4a47fSRichard Kuo static struct clocksource hexagon_clocksource = { 6871e4a47fSRichard Kuo .name = "pcycles", 6971e4a47fSRichard Kuo .rating = 250, 7071e4a47fSRichard Kuo .read = timer_get_cycles, 7171e4a47fSRichard Kuo .mask = CLOCKSOURCE_MASK(64), 7271e4a47fSRichard Kuo .flags = CLOCK_SOURCE_IS_CONTINUOUS, 7371e4a47fSRichard Kuo }; 7471e4a47fSRichard Kuo 7571e4a47fSRichard Kuo static int set_next_event(unsigned long delta, struct clock_event_device *evt) 7671e4a47fSRichard Kuo { 7771e4a47fSRichard Kuo /* Assuming the timer will be disabled when we enter here. */ 7871e4a47fSRichard Kuo 7971e4a47fSRichard Kuo iowrite32(1, &rtos_timer->clear); 8071e4a47fSRichard Kuo iowrite32(0, &rtos_timer->clear); 8171e4a47fSRichard Kuo 8271e4a47fSRichard Kuo iowrite32(delta, &rtos_timer->match); 8371e4a47fSRichard Kuo iowrite32(1 << TIMER_ENABLE, &rtos_timer->enable); 8471e4a47fSRichard Kuo return 0; 8571e4a47fSRichard Kuo } 8671e4a47fSRichard Kuo 8771e4a47fSRichard Kuo #ifdef CONFIG_SMP 8871e4a47fSRichard Kuo /* Broadcast mechanism */ 8971e4a47fSRichard Kuo static void broadcast(const struct cpumask *mask) 9071e4a47fSRichard Kuo { 9171e4a47fSRichard Kuo send_ipi(mask, IPI_TIMER); 9271e4a47fSRichard Kuo } 9371e4a47fSRichard Kuo #endif 9471e4a47fSRichard Kuo 95d70e22d5SViresh Kumar /* XXX Implement set_state_shutdown() */ 9671e4a47fSRichard Kuo static struct clock_event_device hexagon_clockevent_dev = { 9771e4a47fSRichard Kuo .name = "clockevent", 9871e4a47fSRichard Kuo .features = CLOCK_EVT_FEAT_ONESHOT, 9971e4a47fSRichard Kuo .rating = 400, 10071e4a47fSRichard Kuo .irq = RTOS_TIMER_INT, 10171e4a47fSRichard Kuo .set_next_event = set_next_event, 10271e4a47fSRichard Kuo #ifdef CONFIG_SMP 10371e4a47fSRichard Kuo .broadcast = broadcast, 10471e4a47fSRichard Kuo #endif 10571e4a47fSRichard Kuo }; 10671e4a47fSRichard Kuo 10771e4a47fSRichard Kuo #ifdef CONFIG_SMP 10871e4a47fSRichard Kuo static DEFINE_PER_CPU(struct clock_event_device, clock_events); 10971e4a47fSRichard Kuo 11071e4a47fSRichard Kuo void setup_percpu_clockdev(void) 11171e4a47fSRichard Kuo { 11271e4a47fSRichard Kuo int cpu = smp_processor_id(); 11371e4a47fSRichard Kuo struct clock_event_device *ce_dev = &hexagon_clockevent_dev; 11471e4a47fSRichard Kuo struct clock_event_device *dummy_clock_dev = 11571e4a47fSRichard Kuo &per_cpu(clock_events, cpu); 11671e4a47fSRichard Kuo 11771e4a47fSRichard Kuo memcpy(dummy_clock_dev, ce_dev, sizeof(*dummy_clock_dev)); 11871e4a47fSRichard Kuo INIT_LIST_HEAD(&dummy_clock_dev->list); 11971e4a47fSRichard Kuo 12071e4a47fSRichard Kuo dummy_clock_dev->features = CLOCK_EVT_FEAT_DUMMY; 12171e4a47fSRichard Kuo dummy_clock_dev->cpumask = cpumask_of(cpu); 12271e4a47fSRichard Kuo 12371e4a47fSRichard Kuo clockevents_register_device(dummy_clock_dev); 12471e4a47fSRichard Kuo } 12571e4a47fSRichard Kuo 12671e4a47fSRichard Kuo /* Called from smp.c for each CPU's timer ipi call */ 12771e4a47fSRichard Kuo void ipi_timer(void) 12871e4a47fSRichard Kuo { 12971e4a47fSRichard Kuo int cpu = smp_processor_id(); 13071e4a47fSRichard Kuo struct clock_event_device *ce_dev = &per_cpu(clock_events, cpu); 13171e4a47fSRichard Kuo 13271e4a47fSRichard Kuo ce_dev->event_handler(ce_dev); 13371e4a47fSRichard Kuo } 13471e4a47fSRichard Kuo #endif /* CONFIG_SMP */ 13571e4a47fSRichard Kuo 13671e4a47fSRichard Kuo static irqreturn_t timer_interrupt(int irq, void *devid) 13771e4a47fSRichard Kuo { 13871e4a47fSRichard Kuo struct clock_event_device *ce_dev = &hexagon_clockevent_dev; 13971e4a47fSRichard Kuo 14071e4a47fSRichard Kuo iowrite32(0, &rtos_timer->enable); 14171e4a47fSRichard Kuo ce_dev->event_handler(ce_dev); 14271e4a47fSRichard Kuo 14371e4a47fSRichard Kuo return IRQ_HANDLED; 14471e4a47fSRichard Kuo } 14571e4a47fSRichard Kuo 14671e4a47fSRichard Kuo /* This should also be pulled from devtree */ 14771e4a47fSRichard Kuo static struct irqaction rtos_timer_intdesc = { 14871e4a47fSRichard Kuo .handler = timer_interrupt, 14971e4a47fSRichard Kuo .flags = IRQF_TIMER | IRQF_TRIGGER_RISING, 15071e4a47fSRichard Kuo .name = "rtos_timer" 15171e4a47fSRichard Kuo }; 15271e4a47fSRichard Kuo 15371e4a47fSRichard Kuo /* 15471e4a47fSRichard Kuo * time_init_deferred - called by start_kernel to set up timer/clock source 15571e4a47fSRichard Kuo * 15671e4a47fSRichard Kuo * Install the IRQ handler for the clock, setup timers. 15771e4a47fSRichard Kuo * This is done late, as that way, we can use ioremap(). 15871e4a47fSRichard Kuo * 15971e4a47fSRichard Kuo * This runs just before the delay loop is calibrated, and 16071e4a47fSRichard Kuo * is used for delay calibration. 16171e4a47fSRichard Kuo */ 16271e4a47fSRichard Kuo void __init time_init_deferred(void) 16371e4a47fSRichard Kuo { 16471e4a47fSRichard Kuo struct resource *resource = NULL; 16571e4a47fSRichard Kuo struct clock_event_device *ce_dev = &hexagon_clockevent_dev; 16671e4a47fSRichard Kuo 16771e4a47fSRichard Kuo ce_dev->cpumask = cpu_all_mask; 16871e4a47fSRichard Kuo 16971e4a47fSRichard Kuo if (!resource) 17071e4a47fSRichard Kuo resource = rtos_timer_device.resource; 17171e4a47fSRichard Kuo 17271e4a47fSRichard Kuo /* ioremap here means this has to run later, after paging init */ 1733c0f13bcSThomas Meyer rtos_timer = ioremap(resource->start, resource_size(resource)); 17471e4a47fSRichard Kuo 17571e4a47fSRichard Kuo if (!rtos_timer) { 1763c0f13bcSThomas Meyer release_mem_region(resource->start, resource_size(resource)); 17771e4a47fSRichard Kuo } 17871e4a47fSRichard Kuo clocksource_register_khz(&hexagon_clocksource, pcycle_freq_mhz * 1000); 17971e4a47fSRichard Kuo 18071e4a47fSRichard Kuo /* Note: the sim generic RTOS clock is apparently really 18750Hz */ 18171e4a47fSRichard Kuo 18271e4a47fSRichard Kuo /* 18371e4a47fSRichard Kuo * Last arg is some guaranteed seconds for which the conversion will 18471e4a47fSRichard Kuo * work without overflow. 18571e4a47fSRichard Kuo */ 18671e4a47fSRichard Kuo clockevents_calc_mult_shift(ce_dev, sleep_clk_freq, 4); 18771e4a47fSRichard Kuo 18871e4a47fSRichard Kuo ce_dev->max_delta_ns = clockevent_delta2ns(0x7fffffff, ce_dev); 189a60a9fb8SNicolai Stange ce_dev->max_delta_ticks = 0x7fffffff; 19071e4a47fSRichard Kuo ce_dev->min_delta_ns = clockevent_delta2ns(0xf, ce_dev); 191a60a9fb8SNicolai Stange ce_dev->min_delta_ticks = 0xf; 19271e4a47fSRichard Kuo 19371e4a47fSRichard Kuo #ifdef CONFIG_SMP 19471e4a47fSRichard Kuo setup_percpu_clockdev(); 19571e4a47fSRichard Kuo #endif 19671e4a47fSRichard Kuo 19771e4a47fSRichard Kuo clockevents_register_device(ce_dev); 19871e4a47fSRichard Kuo setup_irq(ce_dev->irq, &rtos_timer_intdesc); 19971e4a47fSRichard Kuo } 20071e4a47fSRichard Kuo 20171e4a47fSRichard Kuo void __init time_init(void) 20271e4a47fSRichard Kuo { 20371e4a47fSRichard Kuo late_time_init = time_init_deferred; 20471e4a47fSRichard Kuo } 20571e4a47fSRichard Kuo 206196b933dSChen Gang void __delay(unsigned long cycles) 207196b933dSChen Gang { 208196b933dSChen Gang unsigned long long start = __vmgettime(); 209196b933dSChen Gang 210196b933dSChen Gang while ((__vmgettime() - start) < cycles) 211196b933dSChen Gang cpu_relax(); 212196b933dSChen Gang } 213196b933dSChen Gang EXPORT_SYMBOL(__delay); 214196b933dSChen Gang 21571e4a47fSRichard Kuo /* 21671e4a47fSRichard Kuo * This could become parametric or perhaps even computed at run-time, 21771e4a47fSRichard Kuo * but for now we take the observed simulator jitter. 21871e4a47fSRichard Kuo */ 21971e4a47fSRichard Kuo static long long fudgefactor = 350; /* Maybe lower if kernel optimized. */ 22071e4a47fSRichard Kuo 22171e4a47fSRichard Kuo void __udelay(unsigned long usecs) 22271e4a47fSRichard Kuo { 22371e4a47fSRichard Kuo unsigned long long start = __vmgettime(); 22471e4a47fSRichard Kuo unsigned long long finish = (pcycle_freq_mhz * usecs) - fudgefactor; 22571e4a47fSRichard Kuo 22671e4a47fSRichard Kuo while ((__vmgettime() - start) < finish) 22771e4a47fSRichard Kuo cpu_relax(); /* not sure how this improves readability */ 22871e4a47fSRichard Kuo } 22971e4a47fSRichard Kuo EXPORT_SYMBOL(__udelay); 230