[MIPS] DS1287: Add clockevent driver

Signed-off-by: Yoichi Yuasa <yoichi_yuasa@tripeaks.co.jp>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
This commit is contained in:
Yoichi Yuasa 2008-04-25 12:11:44 +09:00 committed by Ralf Baechle
parent 4247417d84
commit 6457d9fc3b
5 changed files with 185 additions and 49 deletions

View file

@ -81,6 +81,7 @@ config MIPS_COBALT
config MACH_DECSTATION
bool "DECstations"
select BOOT_ELF32
select CEVT_DS1287
select CEVT_R4K
select CSRC_IOASIC
select CSRC_R4K
@ -770,6 +771,9 @@ config BOOT_RAW
config CEVT_BCM1480
bool
config CEVT_DS1287
bool
config CEVT_GT641XX
bool

View file

@ -9,30 +9,15 @@
*
*/
#include <linux/bcd.h>
#include <linux/errno.h>
#include <linux/init.h>
#include <linux/interrupt.h>
#include <linux/kernel.h>
#include <linux/mc146818rtc.h>
#include <linux/mm.h>
#include <linux/module.h>
#include <linux/param.h>
#include <linux/sched.h>
#include <linux/string.h>
#include <linux/time.h>
#include <linux/types.h>
#include <asm/bootinfo.h>
#include <asm/cpu.h>
#include <asm/io.h>
#include <asm/irq.h>
#include <asm/mipsregs.h>
#include <asm/sections.h>
#include <asm/cpu-features.h>
#include <asm/ds1287.h>
#include <asm/time.h>
#include <asm/dec/interrupts.h>
#include <asm/dec/ioasic.h>
#include <asm/dec/ioasic_addrs.h>
#include <asm/dec/machtype.h>
unsigned long read_persistent_clock(void)
@ -139,42 +124,32 @@ int rtc_mips_set_mmss(unsigned long nowtime)
return retval;
}
static int dec_timer_state(void)
{
return (CMOS_READ(RTC_REG_C) & RTC_PF) != 0;
}
static void dec_timer_ack(void)
{
CMOS_READ(RTC_REG_C); /* Ack the RTC interrupt. */
}
static cycle_t dec_ioasic_hpt_read(void)
{
/*
* The free-running counter is 32-bit which is good for about
* 2 minutes, 50 seconds at possible count rates of up to 25MHz.
*/
return ioasic_read(IO_REG_FCTR);
}
void __init plat_time_init(void)
{
mips_timer_ack = dec_timer_ack;
u32 start, end;
int i = HZ / 10;
if (!cpu_has_counter && IOASIC)
/* Set up the rate of periodic DS1287 interrupts. */
ds1287_set_base_clock(HZ);
if (cpu_has_counter) {
while (!ds1287_timer_state())
;
start = read_c0_count();
while (i--)
while (!ds1287_timer_state())
;
end = read_c0_count();
mips_hpt_frequency = (end - start) * 10;
printk(KERN_INFO "MIPS counter frequency %dHz\n",
mips_hpt_frequency);
} else if (IOASIC)
/* For pre-R4k systems we use the I/O ASIC's counter. */
dec_ioasic_clocksource_init();
/* Set up the rate of periodic DS1287 interrupts. */
CMOS_WRITE(RTC_REF_CLCK_32KHZ | (16 - __ffs(HZ)), RTC_REG_A);
}
void __init plat_timer_setup(struct irqaction *irq)
{
setup_irq(dec_interrupt[DEC_IRQ_RTC], irq);
/* Enable periodic DS1287 interrupts. */
CMOS_WRITE(CMOS_READ(RTC_REG_B) | RTC_PIE, RTC_REG_B);
ds1287_clockevent_init(dec_interrupt[DEC_IRQ_RTC]);
}

View file

@ -10,6 +10,7 @@ obj-y += cpu-probe.o branch.o entry.o genex.o irq.o process.o \
obj-$(CONFIG_CEVT_BCM1480) += cevt-bcm1480.o
obj-$(CONFIG_CEVT_R4K) += cevt-r4k.o
obj-$(CONFIG_CEVT_DS1287) += cevt-ds1287.o
obj-$(CONFIG_CEVT_GT641XX) += cevt-gt641xx.o
obj-$(CONFIG_CEVT_SB1250) += cevt-sb1250.o
obj-$(CONFIG_CEVT_TXX9) += cevt-txx9.o

View file

@ -0,0 +1,129 @@
/*
* DS1287 clockevent driver
*
* Copyright (C) 2008 Yoichi Yuasa <yoichi_yuasa@tripeaks.co.jp>
*
* 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.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
#include <linux/clockchips.h>
#include <linux/init.h>
#include <linux/interrupt.h>
#include <linux/mc146818rtc.h>
#include <asm/time.h>
int ds1287_timer_state(void)
{
return (CMOS_READ(RTC_REG_C) & RTC_PF) != 0;
}
int ds1287_set_base_clock(unsigned int hz)
{
u8 rate;
switch (hz) {
case 128:
rate = 0x9;
break;
case 256:
rate = 0x8;
break;
case 1024:
rate = 0x6;
break;
default:
return -EINVAL;
}
CMOS_WRITE(RTC_REF_CLCK_32KHZ | rate, RTC_REG_A);
return 0;
}
static int ds1287_set_next_event(unsigned long delta,
struct clock_event_device *evt)
{
return -EINVAL;
}
static void ds1287_set_mode(enum clock_event_mode mode,
struct clock_event_device *evt)
{
u8 val;
spin_lock(&rtc_lock);
val = CMOS_READ(RTC_REG_B);
switch (mode) {
case CLOCK_EVT_MODE_PERIODIC:
val |= RTC_PIE;
break;
default:
val &= ~RTC_PIE;
break;
}
CMOS_WRITE(val, RTC_REG_B);
spin_unlock(&rtc_lock);
}
static void ds1287_event_handler(struct clock_event_device *dev)
{
}
static struct clock_event_device ds1287_clockevent = {
.name = "ds1287",
.features = CLOCK_EVT_FEAT_PERIODIC,
.cpumask = CPU_MASK_CPU0,
.set_next_event = ds1287_set_next_event,
.set_mode = ds1287_set_mode,
.event_handler = ds1287_event_handler,
};
static irqreturn_t ds1287_interrupt(int irq, void *dev_id)
{
struct clock_event_device *cd = &ds1287_clockevent;
/* Ack the RTC interrupt. */
CMOS_READ(RTC_REG_C);
cd->event_handler(cd);
return IRQ_HANDLED;
}
static struct irqaction ds1287_irqaction = {
.handler = ds1287_interrupt,
.flags = IRQF_DISABLED | IRQF_PERCPU,
.name = "ds1287",
};
int __init ds1287_clockevent_init(int irq)
{
struct clock_event_device *cd;
cd = &ds1287_clockevent;
cd->rating = 100;
cd->irq = irq;
clockevent_set_clock(cd, 32768);
cd->max_delta_ns = clockevent_delta2ns(0x7fffffff, cd);
cd->min_delta_ns = clockevent_delta2ns(0x300, cd);
clockevents_register_device(&ds1287_clockevent);
return setup_irq(irq, &ds1287_irqaction);
}

27
include/asm-mips/ds1287.h Normal file
View file

@ -0,0 +1,27 @@
/*
* DS1287 timer functions.
*
* Copyright (C) 2008 Yoichi Yuasa <yoichi_yuasa@tripeaks.co.jp>
*
* 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.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
#ifndef __ASM_DS1287_H
#define __ASM_DS1287_H
extern int ds1287_timer_state(void);
extern void ds1287_set_base_clock(unsigned int clock);
extern int ds1287_clockevent_init(int irq);
#endif