blob: 07173afe1faf47fd4375c455068ef12b0cec7d7d [file] [log] [blame] [edit]
/*
* rtc.c, RTC(has only timer function) routines for NEC VR4100 series.
*
* Copyright (C) 2003-2004 Yoichi Yuasa <yuasa@hh.iij4u.or.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., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
#include <linux/init.h>
#include <linux/irq.h>
#include <linux/smp.h>
#include <linux/types.h>
#include <asm/io.h>
#include <asm/time.h>
#include <asm/vr41xx/vr41xx.h>
static uint32_t rtc1_base;
static uint32_t rtc2_base;
static uint64_t previous_elapsedtime;
static unsigned int remainder_per_sec;
static unsigned int cycles_per_sec;
static unsigned int cycles_per_jiffy;
static unsigned long epoch_time;
#define CYCLES_PER_JIFFY (CLOCK_TICK_RATE / HZ)
#define REMAINDER_PER_SEC (CLOCK_TICK_RATE - (CYCLES_PER_JIFFY * HZ))
#define CYCLES_PER_100USEC ((CLOCK_TICK_RATE + (10000 / 2)) / 10000)
#define ETIMELREG_TYPE1 KSEG1ADDR(0x0b0000c0)
#define TCLKLREG_TYPE1 KSEG1ADDR(0x0b0001c0)
#define ETIMELREG_TYPE2 KSEG1ADDR(0x0f000100)
#define TCLKLREG_TYPE2 KSEG1ADDR(0x0f000120)
/* RTC 1 registers */
#define ETIMELREG 0x00
#define ETIMEMREG 0x02
#define ETIMEHREG 0x04
/* RFU */
#define ECMPLREG 0x08
#define ECMPMREG 0x0a
#define ECMPHREG 0x0c
/* RFU */
#define RTCL1LREG 0x10
#define RTCL1HREG 0x12
#define RTCL1CNTLREG 0x14
#define RTCL1CNTHREG 0x16
#define RTCL2LREG 0x18
#define RTCL2HREG 0x1a
#define RTCL2CNTLREG 0x1c
#define RTCL2CNTHREG 0x1e
/* RTC 2 registers */
#define TCLKLREG 0x00
#define TCLKHREG 0x02
#define TCLKCNTLREG 0x04
#define TCLKCNTHREG 0x06
/* RFU */
#define RTCINTREG 0x1e
#define TCLOCK_INT 0x08
#define RTCLONG2_INT 0x04
#define RTCLONG1_INT 0x02
#define ELAPSEDTIME_INT 0x01
#define read_rtc1(offset) readw(rtc1_base + (offset))
#define write_rtc1(val, offset) writew((val), rtc1_base + (offset))
#define read_rtc2(offset) readw(rtc2_base + (offset))
#define write_rtc2(val, offset) writew((val), rtc2_base + (offset))
static inline uint64_t read_elapsedtime_counter(void)
{
uint64_t first, second;
uint32_t first_mid, first_low;
uint32_t second_mid, second_low;
do {
first_low = (uint32_t)read_rtc1(ETIMELREG);
first_mid = (uint32_t)read_rtc1(ETIMEMREG);
first = (uint64_t)read_rtc1(ETIMEHREG);
second_low = (uint32_t)read_rtc1(ETIMELREG);
second_mid = (uint32_t)read_rtc1(ETIMEMREG);
second = (uint64_t)read_rtc1(ETIMEHREG);
} while (first_low != second_low || first_mid != second_mid ||
first != second);
return (first << 32) | (uint64_t)((first_mid << 16) | first_low);
}
static inline void write_elapsedtime_counter(uint64_t time)
{
write_rtc1((uint16_t)time, ETIMELREG);
write_rtc1((uint16_t)(time >> 16), ETIMEMREG);
write_rtc1((uint16_t)(time >> 32), ETIMEHREG);
}
static inline void write_elapsedtime_compare(uint64_t time)
{
write_rtc1((uint16_t)time, ECMPLREG);
write_rtc1((uint16_t)(time >> 16), ECMPMREG);
write_rtc1((uint16_t)(time >> 32), ECMPHREG);
}
void vr41xx_set_rtclong1_cycle(uint32_t cycles)
{
write_rtc1((uint16_t)cycles, RTCL1LREG);
write_rtc1((uint16_t)(cycles >> 16), RTCL1HREG);
}
uint32_t vr41xx_read_rtclong1_counter(void)
{
uint32_t first_high, first_low;
uint32_t second_high, second_low;
do {
first_low = (uint32_t)read_rtc1(RTCL1CNTLREG);
first_high = (uint32_t)read_rtc1(RTCL1CNTHREG);
second_low = (uint32_t)read_rtc1(RTCL1CNTLREG);
second_high = (uint32_t)read_rtc1(RTCL1CNTHREG);
} while (first_low != second_low || first_high != second_high);
return (first_high << 16) | first_low;
}
void vr41xx_set_rtclong2_cycle(uint32_t cycles)
{
write_rtc1((uint16_t)cycles, RTCL2LREG);
write_rtc1((uint16_t)(cycles >> 16), RTCL2HREG);
}
uint32_t vr41xx_read_rtclong2_counter(void)
{
uint32_t first_high, first_low;
uint32_t second_high, second_low;
do {
first_low = (uint32_t)read_rtc1(RTCL2CNTLREG);
first_high = (uint32_t)read_rtc1(RTCL2CNTHREG);
second_low = (uint32_t)read_rtc1(RTCL2CNTLREG);
second_high = (uint32_t)read_rtc1(RTCL2CNTHREG);
} while (first_low != second_low || first_high != second_high);
return (first_high << 16) | first_low;
}
void vr41xx_set_tclock_cycle(uint32_t cycles)
{
write_rtc2((uint16_t)cycles, TCLKLREG);
write_rtc2((uint16_t)(cycles >> 16), TCLKHREG);
}
uint32_t vr41xx_read_tclock_counter(void)
{
uint32_t first_high, first_low;
uint32_t second_high, second_low;
do {
first_low = (uint32_t)read_rtc2(TCLKCNTLREG);
first_high = (uint32_t)read_rtc2(TCLKCNTHREG);
second_low = (uint32_t)read_rtc2(TCLKCNTLREG);
second_high = (uint32_t)read_rtc2(TCLKCNTHREG);
} while (first_low != second_low || first_high != second_high);
return (first_high << 16) | first_low;
}
static void vr41xx_timer_ack(void)
{
uint64_t cur;
write_rtc2(ELAPSEDTIME_INT, RTCINTREG);
previous_elapsedtime += (uint64_t)cycles_per_jiffy;
cycles_per_sec += cycles_per_jiffy;
if (cycles_per_sec >= CLOCK_TICK_RATE) {
cycles_per_sec = 0;
remainder_per_sec = REMAINDER_PER_SEC;
}
cycles_per_jiffy = 0;
do {
cycles_per_jiffy += CYCLES_PER_JIFFY;
if (remainder_per_sec > 0) {
cycles_per_jiffy++;
remainder_per_sec--;
}
cur = read_elapsedtime_counter();
} while (cur >= previous_elapsedtime + (uint64_t)cycles_per_jiffy);
write_elapsedtime_compare(previous_elapsedtime + (uint64_t)cycles_per_jiffy);
}
static void vr41xx_hpt_init(unsigned int count)
{
}
static unsigned int vr41xx_hpt_read(void)
{
uint64_t cur;
cur = read_elapsedtime_counter();
return (unsigned int)cur;
}
static unsigned long vr41xx_gettimeoffset(void)
{
uint64_t cur;
unsigned long gap;
cur = read_elapsedtime_counter();
gap = (unsigned long)(cur - previous_elapsedtime);
gap = gap / CYCLES_PER_100USEC * 100; /* usec */
return gap;
}
static unsigned long vr41xx_get_time(void)
{
uint64_t counts;
counts = read_elapsedtime_counter();
counts >>= 15;
return epoch_time + (unsigned long)counts;
}
static int vr41xx_set_time(unsigned long sec)
{
if (sec < epoch_time)
return -EINVAL;
sec -= epoch_time;
write_elapsedtime_counter((uint64_t)sec << 15);
return 0;
}
void vr41xx_set_epoch_time(unsigned long time)
{
epoch_time = time;
}
static void __init vr41xx_time_init(void)
{
switch (current_cpu_data.cputype) {
case CPU_VR4111:
case CPU_VR4121:
rtc1_base = ETIMELREG_TYPE1;
rtc2_base = TCLKLREG_TYPE1;
break;
case CPU_VR4122:
case CPU_VR4131:
case CPU_VR4133:
rtc1_base = ETIMELREG_TYPE2;
rtc2_base = TCLKLREG_TYPE2;
break;
default:
panic("Unexpected CPU of NEC VR4100 series");
break;
}
mips_timer_ack = vr41xx_timer_ack;
mips_hpt_init = vr41xx_hpt_init;
mips_hpt_read = vr41xx_hpt_read;
mips_hpt_frequency = CLOCK_TICK_RATE;
if (epoch_time == 0)
epoch_time = mktime(1970, 1, 1, 0, 0, 0);
rtc_get_time = vr41xx_get_time;
rtc_set_time = vr41xx_set_time;
}
static void __init vr41xx_timer_setup(struct irqaction *irq)
{
do_gettimeoffset = vr41xx_gettimeoffset;
remainder_per_sec = REMAINDER_PER_SEC;
cycles_per_jiffy = CYCLES_PER_JIFFY;
if (remainder_per_sec > 0) {
cycles_per_jiffy++;
remainder_per_sec--;
}
previous_elapsedtime = read_elapsedtime_counter();
write_elapsedtime_compare(previous_elapsedtime + (uint64_t)cycles_per_jiffy);
write_rtc2(ELAPSEDTIME_INT, RTCINTREG);
setup_irq(ELAPSEDTIME_IRQ, irq);
}
static int __init vr41xx_rtc_init(void)
{
board_time_init = vr41xx_time_init;
board_timer_setup = vr41xx_timer_setup;
return 0;
}
early_initcall(vr41xx_rtc_init);