| /* |
| * arch/arm/plat-iop/time.c |
| * |
| * Timer code for IOP32x and IOP33x based systems |
| * |
| * Author: Deepak Saxena <dsaxena@mvista.com> |
| * |
| * Copyright 2002-2003 MontaVista Software Inc. |
| * |
| * 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 <linux/kernel.h> |
| #include <linux/interrupt.h> |
| #include <linux/time.h> |
| #include <linux/init.h> |
| #include <linux/timex.h> |
| #include <linux/io.h> |
| #include <linux/clocksource.h> |
| #include <linux/clockchips.h> |
| #include <mach/hardware.h> |
| #include <asm/irq.h> |
| #include <asm/uaccess.h> |
| #include <asm/mach/irq.h> |
| #include <asm/mach/time.h> |
| #include <mach/time.h> |
| |
| /* |
| * IOP clocksource (free-running timer 1). |
| */ |
| static cycle_t iop_clocksource_read(struct clocksource *unused) |
| { |
| return 0xffffffffu - read_tcr1(); |
| } |
| |
| static struct clocksource iop_clocksource = { |
| .name = "iop_timer1", |
| .rating = 300, |
| .read = iop_clocksource_read, |
| .mask = CLOCKSOURCE_MASK(32), |
| .flags = CLOCK_SOURCE_IS_CONTINUOUS, |
| }; |
| |
| static void __init iop_clocksource_set_hz(struct clocksource *cs, unsigned int hz) |
| { |
| u64 temp; |
| u32 shift; |
| |
| /* Find shift and mult values for hz. */ |
| shift = 32; |
| do { |
| temp = (u64) NSEC_PER_SEC << shift; |
| do_div(temp, hz); |
| if ((temp >> 32) == 0) |
| break; |
| } while (--shift != 0); |
| |
| cs->shift = shift; |
| cs->mult = (u32) temp; |
| |
| printk(KERN_INFO "clocksource: %s uses shift %u mult %#x\n", |
| cs->name, cs->shift, cs->mult); |
| } |
| |
| /* |
| * IOP clockevents (interrupting timer 0). |
| */ |
| static int iop_set_next_event(unsigned long delta, |
| struct clock_event_device *unused) |
| { |
| u32 tmr = IOP_TMR_PRIVILEGED | IOP_TMR_RATIO_1_1; |
| |
| BUG_ON(delta == 0); |
| write_tmr0(tmr & ~(IOP_TMR_EN | IOP_TMR_RELOAD)); |
| write_tcr0(delta); |
| write_tmr0((tmr & ~IOP_TMR_RELOAD) | IOP_TMR_EN); |
| |
| return 0; |
| } |
| |
| static unsigned long ticks_per_jiffy; |
| |
| static void iop_set_mode(enum clock_event_mode mode, |
| struct clock_event_device *unused) |
| { |
| u32 tmr = read_tmr0(); |
| |
| switch (mode) { |
| case CLOCK_EVT_MODE_PERIODIC: |
| write_tmr0(tmr & ~IOP_TMR_EN); |
| write_tcr0(ticks_per_jiffy - 1); |
| tmr |= (IOP_TMR_RELOAD | IOP_TMR_EN); |
| break; |
| case CLOCK_EVT_MODE_ONESHOT: |
| /* ->set_next_event sets period and enables timer */ |
| tmr &= ~(IOP_TMR_RELOAD | IOP_TMR_EN); |
| break; |
| case CLOCK_EVT_MODE_RESUME: |
| tmr |= IOP_TMR_EN; |
| break; |
| case CLOCK_EVT_MODE_SHUTDOWN: |
| case CLOCK_EVT_MODE_UNUSED: |
| default: |
| tmr &= ~IOP_TMR_EN; |
| break; |
| } |
| |
| write_tmr0(tmr); |
| } |
| |
| static struct clock_event_device iop_clockevent = { |
| .name = "iop_timer0", |
| .features = CLOCK_EVT_FEAT_PERIODIC | CLOCK_EVT_FEAT_ONESHOT, |
| .rating = 300, |
| .set_next_event = iop_set_next_event, |
| .set_mode = iop_set_mode, |
| }; |
| |
| static void __init iop_clockevent_set_hz(struct clock_event_device *ce, unsigned int hz) |
| { |
| u64 temp; |
| u32 shift; |
| |
| /* Find shift and mult values for hz. */ |
| shift = 32; |
| do { |
| temp = (u64) hz << shift; |
| do_div(temp, NSEC_PER_SEC); |
| if ((temp >> 32) == 0) |
| break; |
| } while (--shift != 0); |
| |
| ce->shift = shift; |
| ce->mult = (u32) temp; |
| |
| printk(KERN_INFO "clockevent: %s uses shift %u mult %#lx\n", |
| ce->name, ce->shift, ce->mult); |
| } |
| |
| static irqreturn_t |
| iop_timer_interrupt(int irq, void *dev_id) |
| { |
| struct clock_event_device *evt = dev_id; |
| |
| write_tisr(1); |
| evt->event_handler(evt); |
| return IRQ_HANDLED; |
| } |
| |
| static struct irqaction iop_timer_irq = { |
| .name = "IOP Timer Tick", |
| .handler = iop_timer_interrupt, |
| .flags = IRQF_DISABLED | IRQF_TIMER | IRQF_IRQPOLL, |
| .dev_id = &iop_clockevent, |
| }; |
| |
| static unsigned long iop_tick_rate; |
| unsigned long get_iop_tick_rate(void) |
| { |
| return iop_tick_rate; |
| } |
| EXPORT_SYMBOL(get_iop_tick_rate); |
| |
| void __init iop_init_time(unsigned long tick_rate) |
| { |
| u32 timer_ctl; |
| |
| ticks_per_jiffy = DIV_ROUND_CLOSEST(tick_rate, HZ); |
| iop_tick_rate = tick_rate; |
| |
| timer_ctl = IOP_TMR_EN | IOP_TMR_PRIVILEGED | |
| IOP_TMR_RELOAD | IOP_TMR_RATIO_1_1; |
| |
| /* |
| * Set up interrupting clockevent timer 0. |
| */ |
| write_tmr0(timer_ctl & ~IOP_TMR_EN); |
| setup_irq(IRQ_IOP_TIMER0, &iop_timer_irq); |
| iop_clockevent_set_hz(&iop_clockevent, tick_rate); |
| iop_clockevent.max_delta_ns = |
| clockevent_delta2ns(0xfffffffe, &iop_clockevent); |
| iop_clockevent.min_delta_ns = |
| clockevent_delta2ns(0xf, &iop_clockevent); |
| iop_clockevent.cpumask = cpumask_of(0); |
| clockevents_register_device(&iop_clockevent); |
| write_trr0(ticks_per_jiffy - 1); |
| write_tcr0(ticks_per_jiffy - 1); |
| write_tmr0(timer_ctl); |
| |
| /* |
| * Set up free-running clocksource timer 1. |
| */ |
| write_trr1(0xffffffff); |
| write_tcr1(0xffffffff); |
| write_tmr1(timer_ctl); |
| iop_clocksource_set_hz(&iop_clocksource, tick_rate); |
| clocksource_register(&iop_clocksource); |
| } |