171e4a47fSRichard Kuo /* 271e4a47fSRichard Kuo * Time related functions for Hexagon architecture 371e4a47fSRichard Kuo * 4e1858b2aSRichard Kuo * Copyright (c) 2010-2011, The Linux Foundation. All rights reserved. 571e4a47fSRichard Kuo * 671e4a47fSRichard Kuo * This program is free software; you can redistribute it and/or modify 771e4a47fSRichard Kuo * it under the terms of the GNU General Public License version 2 and 871e4a47fSRichard Kuo * only version 2 as published by the Free Software Foundation. 971e4a47fSRichard Kuo * 1071e4a47fSRichard Kuo * This program is distributed in the hope that it will be useful, 1171e4a47fSRichard Kuo * but WITHOUT ANY WARRANTY; without even the implied warranty of 1271e4a47fSRichard Kuo * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 1371e4a47fSRichard Kuo * GNU General Public License for more details. 1471e4a47fSRichard Kuo * 1571e4a47fSRichard Kuo * You should have received a copy of the GNU General Public License 1671e4a47fSRichard Kuo * along with this program; if not, write to the Free Software 1771e4a47fSRichard Kuo * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 1871e4a47fSRichard Kuo * 02110-1301, USA. 1971e4a47fSRichard Kuo */ 2071e4a47fSRichard Kuo 2171e4a47fSRichard Kuo #include <linux/init.h> 2271e4a47fSRichard Kuo #include <linux/clockchips.h> 2371e4a47fSRichard Kuo #include <linux/clocksource.h> 2471e4a47fSRichard Kuo #include <linux/interrupt.h> 2571e4a47fSRichard Kuo #include <linux/err.h> 2671e4a47fSRichard Kuo #include <linux/platform_device.h> 2771e4a47fSRichard Kuo #include <linux/ioport.h> 2871e4a47fSRichard Kuo #include <linux/of.h> 2971e4a47fSRichard Kuo #include <linux/of_address.h> 3071e4a47fSRichard Kuo #include <linux/of_irq.h> 316bbbc30cSRichard Kuo #include <linux/module.h> 3271e4a47fSRichard Kuo 3371e4a47fSRichard Kuo #include <asm/timer-regs.h> 3471e4a47fSRichard Kuo #include <asm/hexagon_vm.h> 3571e4a47fSRichard Kuo 3671e4a47fSRichard Kuo /* 3771e4a47fSRichard Kuo * For the clocksource we need: 3871e4a47fSRichard Kuo * pcycle frequency (600MHz) 3971e4a47fSRichard Kuo * For the loops_per_jiffy we need: 4071e4a47fSRichard Kuo * thread/cpu frequency (100MHz) 4171e4a47fSRichard Kuo * And for the timer, we need: 4271e4a47fSRichard Kuo * sleep clock rate 4371e4a47fSRichard Kuo */ 4471e4a47fSRichard Kuo 4571e4a47fSRichard Kuo cycles_t pcycle_freq_mhz; 4671e4a47fSRichard Kuo cycles_t thread_freq_mhz; 4771e4a47fSRichard Kuo cycles_t sleep_clk_freq; 4871e4a47fSRichard Kuo 4971e4a47fSRichard Kuo static struct resource rtos_timer_resources[] = { 5071e4a47fSRichard Kuo { 5171e4a47fSRichard Kuo .start = RTOS_TIMER_REGS_ADDR, 5271e4a47fSRichard Kuo .end = RTOS_TIMER_REGS_ADDR+PAGE_SIZE-1, 5371e4a47fSRichard Kuo .flags = IORESOURCE_MEM, 5471e4a47fSRichard Kuo }, 5571e4a47fSRichard Kuo }; 5671e4a47fSRichard Kuo 5771e4a47fSRichard Kuo static struct platform_device rtos_timer_device = { 5871e4a47fSRichard Kuo .name = "rtos_timer", 5971e4a47fSRichard Kuo .id = -1, 6071e4a47fSRichard Kuo .num_resources = ARRAY_SIZE(rtos_timer_resources), 6171e4a47fSRichard Kuo .resource = rtos_timer_resources, 6271e4a47fSRichard Kuo }; 6371e4a47fSRichard Kuo 6471e4a47fSRichard Kuo /* A lot of this stuff should move into a platform specific section. */ 6571e4a47fSRichard Kuo struct adsp_hw_timer_struct { 6671e4a47fSRichard Kuo u32 match; /* Match value */ 6771e4a47fSRichard Kuo u32 count; 6871e4a47fSRichard Kuo u32 enable; /* [1] - CLR_ON_MATCH_EN, [0] - EN */ 6971e4a47fSRichard Kuo u32 clear; /* one-shot register that clears the count */ 7071e4a47fSRichard Kuo }; 7171e4a47fSRichard Kuo 7271e4a47fSRichard Kuo /* Look for "TCX0" for related constants. */ 7371e4a47fSRichard Kuo static __iomem struct adsp_hw_timer_struct *rtos_timer; 7471e4a47fSRichard Kuo 75a5a1d1c2SThomas Gleixner static u64 timer_get_cycles(struct clocksource *cs) 7671e4a47fSRichard Kuo { 77a5a1d1c2SThomas Gleixner return (u64) __vmgettime(); 7871e4a47fSRichard Kuo } 7971e4a47fSRichard Kuo 8071e4a47fSRichard Kuo static struct clocksource hexagon_clocksource = { 8171e4a47fSRichard Kuo .name = "pcycles", 8271e4a47fSRichard Kuo .rating = 250, 8371e4a47fSRichard Kuo .read = timer_get_cycles, 8471e4a47fSRichard Kuo .mask = CLOCKSOURCE_MASK(64), 8571e4a47fSRichard Kuo .flags = CLOCK_SOURCE_IS_CONTINUOUS, 8671e4a47fSRichard Kuo }; 8771e4a47fSRichard Kuo 8871e4a47fSRichard Kuo static int set_next_event(unsigned long delta, struct clock_event_device *evt) 8971e4a47fSRichard Kuo { 9071e4a47fSRichard Kuo /* Assuming the timer will be disabled when we enter here. */ 9171e4a47fSRichard Kuo 9271e4a47fSRichard Kuo iowrite32(1, &rtos_timer->clear); 9371e4a47fSRichard Kuo iowrite32(0, &rtos_timer->clear); 9471e4a47fSRichard Kuo 9571e4a47fSRichard Kuo iowrite32(delta, &rtos_timer->match); 9671e4a47fSRichard Kuo iowrite32(1 << TIMER_ENABLE, &rtos_timer->enable); 9771e4a47fSRichard Kuo return 0; 9871e4a47fSRichard Kuo } 9971e4a47fSRichard Kuo 10071e4a47fSRichard Kuo #ifdef CONFIG_SMP 10171e4a47fSRichard Kuo /* Broadcast mechanism */ 10271e4a47fSRichard Kuo static void broadcast(const struct cpumask *mask) 10371e4a47fSRichard Kuo { 10471e4a47fSRichard Kuo send_ipi(mask, IPI_TIMER); 10571e4a47fSRichard Kuo } 10671e4a47fSRichard Kuo #endif 10771e4a47fSRichard Kuo 108d70e22d5SViresh Kumar /* XXX Implement set_state_shutdown() */ 10971e4a47fSRichard Kuo static struct clock_event_device hexagon_clockevent_dev = { 11071e4a47fSRichard Kuo .name = "clockevent", 11171e4a47fSRichard Kuo .features = CLOCK_EVT_FEAT_ONESHOT, 11271e4a47fSRichard Kuo .rating = 400, 11371e4a47fSRichard Kuo .irq = RTOS_TIMER_INT, 11471e4a47fSRichard Kuo .set_next_event = set_next_event, 11571e4a47fSRichard Kuo #ifdef CONFIG_SMP 11671e4a47fSRichard Kuo .broadcast = broadcast, 11771e4a47fSRichard Kuo #endif 11871e4a47fSRichard Kuo }; 11971e4a47fSRichard Kuo 12071e4a47fSRichard Kuo #ifdef CONFIG_SMP 12171e4a47fSRichard Kuo static DEFINE_PER_CPU(struct clock_event_device, clock_events); 12271e4a47fSRichard Kuo 12371e4a47fSRichard Kuo void setup_percpu_clockdev(void) 12471e4a47fSRichard Kuo { 12571e4a47fSRichard Kuo int cpu = smp_processor_id(); 12671e4a47fSRichard Kuo struct clock_event_device *ce_dev = &hexagon_clockevent_dev; 12771e4a47fSRichard Kuo struct clock_event_device *dummy_clock_dev = 12871e4a47fSRichard Kuo &per_cpu(clock_events, cpu); 12971e4a47fSRichard Kuo 13071e4a47fSRichard Kuo memcpy(dummy_clock_dev, ce_dev, sizeof(*dummy_clock_dev)); 13171e4a47fSRichard Kuo INIT_LIST_HEAD(&dummy_clock_dev->list); 13271e4a47fSRichard Kuo 13371e4a47fSRichard Kuo dummy_clock_dev->features = CLOCK_EVT_FEAT_DUMMY; 13471e4a47fSRichard Kuo dummy_clock_dev->cpumask = cpumask_of(cpu); 13571e4a47fSRichard Kuo 13671e4a47fSRichard Kuo clockevents_register_device(dummy_clock_dev); 13771e4a47fSRichard Kuo } 13871e4a47fSRichard Kuo 13971e4a47fSRichard Kuo /* Called from smp.c for each CPU's timer ipi call */ 14071e4a47fSRichard Kuo void ipi_timer(void) 14171e4a47fSRichard Kuo { 14271e4a47fSRichard Kuo int cpu = smp_processor_id(); 14371e4a47fSRichard Kuo struct clock_event_device *ce_dev = &per_cpu(clock_events, cpu); 14471e4a47fSRichard Kuo 14571e4a47fSRichard Kuo ce_dev->event_handler(ce_dev); 14671e4a47fSRichard Kuo } 14771e4a47fSRichard Kuo #endif /* CONFIG_SMP */ 14871e4a47fSRichard Kuo 14971e4a47fSRichard Kuo static irqreturn_t timer_interrupt(int irq, void *devid) 15071e4a47fSRichard Kuo { 15171e4a47fSRichard Kuo struct clock_event_device *ce_dev = &hexagon_clockevent_dev; 15271e4a47fSRichard Kuo 15371e4a47fSRichard Kuo iowrite32(0, &rtos_timer->enable); 15471e4a47fSRichard Kuo ce_dev->event_handler(ce_dev); 15571e4a47fSRichard Kuo 15671e4a47fSRichard Kuo return IRQ_HANDLED; 15771e4a47fSRichard Kuo } 15871e4a47fSRichard Kuo 15971e4a47fSRichard Kuo /* This should also be pulled from devtree */ 16071e4a47fSRichard Kuo static struct irqaction rtos_timer_intdesc = { 16171e4a47fSRichard Kuo .handler = timer_interrupt, 16271e4a47fSRichard Kuo .flags = IRQF_TIMER | IRQF_TRIGGER_RISING, 16371e4a47fSRichard Kuo .name = "rtos_timer" 16471e4a47fSRichard Kuo }; 16571e4a47fSRichard Kuo 16671e4a47fSRichard Kuo /* 16771e4a47fSRichard Kuo * time_init_deferred - called by start_kernel to set up timer/clock source 16871e4a47fSRichard Kuo * 16971e4a47fSRichard Kuo * Install the IRQ handler for the clock, setup timers. 17071e4a47fSRichard Kuo * This is done late, as that way, we can use ioremap(). 17171e4a47fSRichard Kuo * 17271e4a47fSRichard Kuo * This runs just before the delay loop is calibrated, and 17371e4a47fSRichard Kuo * is used for delay calibration. 17471e4a47fSRichard Kuo */ 17571e4a47fSRichard Kuo void __init time_init_deferred(void) 17671e4a47fSRichard Kuo { 17771e4a47fSRichard Kuo struct resource *resource = NULL; 17871e4a47fSRichard Kuo struct clock_event_device *ce_dev = &hexagon_clockevent_dev; 17971e4a47fSRichard Kuo 18071e4a47fSRichard Kuo ce_dev->cpumask = cpu_all_mask; 18171e4a47fSRichard Kuo 18271e4a47fSRichard Kuo if (!resource) 18371e4a47fSRichard Kuo resource = rtos_timer_device.resource; 18471e4a47fSRichard Kuo 18571e4a47fSRichard Kuo /* ioremap here means this has to run later, after paging init */ 1863c0f13bcSThomas Meyer rtos_timer = ioremap(resource->start, resource_size(resource)); 18771e4a47fSRichard Kuo 18871e4a47fSRichard Kuo if (!rtos_timer) { 1893c0f13bcSThomas Meyer release_mem_region(resource->start, resource_size(resource)); 19071e4a47fSRichard Kuo } 19171e4a47fSRichard Kuo clocksource_register_khz(&hexagon_clocksource, pcycle_freq_mhz * 1000); 19271e4a47fSRichard Kuo 19371e4a47fSRichard Kuo /* Note: the sim generic RTOS clock is apparently really 18750Hz */ 19471e4a47fSRichard Kuo 19571e4a47fSRichard Kuo /* 19671e4a47fSRichard Kuo * Last arg is some guaranteed seconds for which the conversion will 19771e4a47fSRichard Kuo * work without overflow. 19871e4a47fSRichard Kuo */ 19971e4a47fSRichard Kuo clockevents_calc_mult_shift(ce_dev, sleep_clk_freq, 4); 20071e4a47fSRichard Kuo 20171e4a47fSRichard Kuo ce_dev->max_delta_ns = clockevent_delta2ns(0x7fffffff, ce_dev); 202a60a9fb8SNicolai Stange ce_dev->max_delta_ticks = 0x7fffffff; 20371e4a47fSRichard Kuo ce_dev->min_delta_ns = clockevent_delta2ns(0xf, ce_dev); 204a60a9fb8SNicolai Stange ce_dev->min_delta_ticks = 0xf; 20571e4a47fSRichard Kuo 20671e4a47fSRichard Kuo #ifdef CONFIG_SMP 20771e4a47fSRichard Kuo setup_percpu_clockdev(); 20871e4a47fSRichard Kuo #endif 20971e4a47fSRichard Kuo 21071e4a47fSRichard Kuo clockevents_register_device(ce_dev); 21171e4a47fSRichard Kuo setup_irq(ce_dev->irq, &rtos_timer_intdesc); 21271e4a47fSRichard Kuo } 21371e4a47fSRichard Kuo 21471e4a47fSRichard Kuo void __init time_init(void) 21571e4a47fSRichard Kuo { 21671e4a47fSRichard Kuo late_time_init = time_init_deferred; 21771e4a47fSRichard Kuo } 21871e4a47fSRichard Kuo 219196b933dSChen Gang void __delay(unsigned long cycles) 220196b933dSChen Gang { 221196b933dSChen Gang unsigned long long start = __vmgettime(); 222196b933dSChen Gang 223196b933dSChen Gang while ((__vmgettime() - start) < cycles) 224196b933dSChen Gang cpu_relax(); 225196b933dSChen Gang } 226196b933dSChen Gang EXPORT_SYMBOL(__delay); 227196b933dSChen Gang 22871e4a47fSRichard Kuo /* 22971e4a47fSRichard Kuo * This could become parametric or perhaps even computed at run-time, 23071e4a47fSRichard Kuo * but for now we take the observed simulator jitter. 23171e4a47fSRichard Kuo */ 23271e4a47fSRichard Kuo static long long fudgefactor = 350; /* Maybe lower if kernel optimized. */ 23371e4a47fSRichard Kuo 23471e4a47fSRichard Kuo void __udelay(unsigned long usecs) 23571e4a47fSRichard Kuo { 23671e4a47fSRichard Kuo unsigned long long start = __vmgettime(); 23771e4a47fSRichard Kuo unsigned long long finish = (pcycle_freq_mhz * usecs) - fudgefactor; 23871e4a47fSRichard Kuo 23971e4a47fSRichard Kuo while ((__vmgettime() - start) < finish) 24071e4a47fSRichard Kuo cpu_relax(); /* not sure how this improves readability */ 24171e4a47fSRichard Kuo } 24271e4a47fSRichard Kuo EXPORT_SYMBOL(__udelay); 243