mirror of
git://projects.qi-hardware.com/openwrt-xburst.git
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dc3d3f1c49
it's basically also provided by ingenic and nativly based on 2.6.27, adjusted to fit into the OpenWrt-environment
130 lines
3.3 KiB
C
130 lines
3.3 KiB
C
/*
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* linux/arch/mips/jz4730/time.c
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*
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* Setting up the clock on the JZ4730 boards.
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*
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* Copyright (c) 2006-2008 Ingenic Semiconductor Inc.
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* Author: <jlwei@ingenic.cn>
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License version 2 as
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* published by the Free Software Foundation.
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*/
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#include <linux/types.h>
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#include <linux/interrupt.h>
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#include <linux/time.h>
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#include <linux/clockchips.h>
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#include <asm/time.h>
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#include <asm/jzsoc.h>
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#define JZ_TIMER_CHAN 0
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#define JZ_TIMER_IRQ IRQ_OST0
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#define JZ_TIMER_CLOCK JZ_EXTAL
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static unsigned int timer_latch;
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void (*jz_timer_callback)(void);
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static void jz_set_mode(enum clock_event_mode mode,
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struct clock_event_device *evt)
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{
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switch (mode) {
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case CLOCK_EVT_MODE_PERIODIC:
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break;
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case CLOCK_EVT_MODE_ONESHOT:
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case CLOCK_EVT_MODE_UNUSED:
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case CLOCK_EVT_MODE_SHUTDOWN:
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break;
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case CLOCK_EVT_MODE_RESUME:
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break;
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}
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}
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static struct clock_event_device jz_clockevent_device = {
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.name = "jz-timer",
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.features = CLOCK_EVT_FEAT_PERIODIC,
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/* .mult, .shift, .max_delta_ns and .min_delta_ns left uninitialized */
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.rating = 300,
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.irq = JZ_TIMER_IRQ,
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.set_mode = jz_set_mode,
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};
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static irqreturn_t jz_timer_interrupt(int irq, void *dev_id)
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{
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struct clock_event_device *cd = dev_id;
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__ost_clear_uf(JZ_TIMER_CHAN); /* ACK timer */
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if (jz_timer_callback)
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jz_timer_callback();
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cd->event_handler(cd);
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return IRQ_HANDLED;
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}
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static struct irqaction jz_irqaction = {
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.handler = jz_timer_interrupt,
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.flags = IRQF_DISABLED | IRQF_PERCPU,
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.name = "jz-timer",
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};
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cycle_t jz_get_cycles(void)
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{
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unsigned int jz_timer_cnt;
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#if 0 /* clock source use pll, read directly */
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jz_timer_cnt = timer_latch - REG_OST_TCNT(JZ_TIMER_CHAN);
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#else /* clock source use RTCClock or Extall Clock, wait read ready */
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jz_timer_cnt = REG_OST_TCNT(JZ_TIMER_CHAN); /* dummy read */
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while ( __ost_is_busy(JZ_TIMER_CHAN) ) ; /* wait read ready */
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jz_timer_cnt = timer_latch - REG_OST_TCRB(JZ_TIMER_CHAN);
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#endif
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/* convert jiffes to jz timer cycles */
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return (cycle_t)( jiffies*((JZ_TIMER_CLOCK)/HZ) + jz_timer_cnt);
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}
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static struct clocksource clocksource_jz = {
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.name = "jz_clocksource",
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.rating = 300,
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.read = jz_get_cycles,
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.mask = 0xFFFFFFFF,
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.shift = 10, /* control clocksource.mult's accuracy */
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.flags = CLOCK_SOURCE_WATCHDOG,
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};
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static int __init jz_clocksource_init(void)
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{
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clocksource_jz.mult = clocksource_hz2mult(JZ_TIMER_CLOCK, clocksource_jz.shift);
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clocksource_register(&clocksource_jz);
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return 0;
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}
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static void __init jz_timer_setup(void)
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{
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struct clock_event_device *cd = &jz_clockevent_device;
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struct irqaction *action = &jz_irqaction;
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unsigned int cpu = smp_processor_id();
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jz_clocksource_init();
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cd->cpumask = cpumask_of_cpu(cpu);
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clockevents_register_device(cd);
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action->dev_id = cd;
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setup_irq(JZ_TIMER_IRQ, &jz_irqaction);
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}
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void __init plat_time_init(void)
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{
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/* Init timer, timer clock soure use extal clock */
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timer_latch = (JZ_TIMER_CLOCK + (HZ>>1)) / HZ;
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__ost_set_mode(JZ_TIMER_CHAN, OST_TCSR_UIE | OST_TCSR_CKS_EXTAL);
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__ost_set_reload(JZ_TIMER_CHAN, timer_latch);
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__ost_set_count(JZ_TIMER_CHAN, timer_latch);
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__ost_enable_channel(JZ_TIMER_CHAN);
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jz_timer_setup();
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}
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