diff options
Diffstat (limited to 'arch/m68k/atari/time.c')
| -rw-r--r-- | arch/m68k/atari/time.c | 145 |
1 files changed, 55 insertions, 90 deletions
diff --git a/arch/m68k/atari/time.c b/arch/m68k/atari/time.c index c549b48174ec..3453c6dc6b41 100644 --- a/arch/m68k/atari/time.c +++ b/arch/m68k/atari/time.c @@ -16,47 +16,82 @@ #include <linux/init.h> #include <linux/rtc.h> #include <linux/bcd.h> +#include <linux/clocksource.h> #include <linux/delay.h> #include <linux/export.h> #include <asm/atariints.h> +#include <asm/machdep.h> + +#include "atari.h" DEFINE_SPINLOCK(rtc_lock); EXPORT_SYMBOL_GPL(rtc_lock); +static u64 atari_read_clk(struct clocksource *cs); + +static struct clocksource atari_clk = { + .name = "mfp", + .rating = 100, + .read = atari_read_clk, + .mask = CLOCKSOURCE_MASK(32), + .flags = CLOCK_SOURCE_IS_CONTINUOUS, +}; + +static u32 clk_total; +static u8 last_timer_count; + +static irqreturn_t mfp_timer_c_handler(int irq, void *dev_id) +{ + unsigned long flags; + + local_irq_save(flags); + do { + last_timer_count = st_mfp.tim_dt_c; + } while (last_timer_count == 1); + clk_total += INT_TICKS; + legacy_timer_tick(1); + timer_heartbeat(); + local_irq_restore(flags); + + return IRQ_HANDLED; +} + void __init -atari_sched_init(irq_handler_t timer_routine) +atari_sched_init(void) { /* set Timer C data Register */ st_mfp.tim_dt_c = INT_TICKS; /* start timer C, div = 1:100 */ st_mfp.tim_ct_cd = (st_mfp.tim_ct_cd & 15) | 0x60; /* install interrupt service routine for MFP Timer C */ - if (request_irq(IRQ_MFP_TIMC, timer_routine, 0, "timer", timer_routine)) + if (request_irq(IRQ_MFP_TIMC, mfp_timer_c_handler, IRQF_TIMER, "timer", + NULL)) pr_err("Couldn't register timer interrupt\n"); + + clocksource_register_hz(&atari_clk, INT_CLK); } /* ++andreas: gettimeoffset fixed to check for pending interrupt */ -#define TICK_SIZE 10000 - -/* This is always executed with interrupts disabled. */ -u32 atari_gettimeoffset(void) +static u64 atari_read_clk(struct clocksource *cs) { - u32 ticks, offset = 0; - - /* read MFP timer C current value */ - ticks = st_mfp.tim_dt_c; - /* The probability of underflow is less than 2% */ - if (ticks > INT_TICKS - INT_TICKS / 50) - /* Check for pending timer interrupt */ - if (st_mfp.int_pn_b & (1 << 5)) - offset = TICK_SIZE; - - ticks = INT_TICKS - ticks; - ticks = ticks * 10000L / INT_TICKS; - - return (ticks + offset) * 1000; + unsigned long flags; + u8 count; + u32 ticks; + + local_irq_save(flags); + /* Ensure that the count is monotonically decreasing, even though + * the result may briefly stop changing after counter wrap-around. + */ + count = min(st_mfp.tim_dt_c, last_timer_count); + last_timer_count = count; + + ticks = INT_TICKS - count; + ticks += clk_total; + local_irq_restore(flags); + + return ticks; } @@ -284,73 +319,3 @@ int atari_tt_hwclk( int op, struct rtc_time *t ) return( 0 ); } - - -int atari_mste_set_clock_mmss (unsigned long nowtime) -{ - short real_seconds = nowtime % 60, real_minutes = (nowtime / 60) % 60; - struct MSTE_RTC val; - unsigned char rtc_minutes; - - mste_read(&val); - rtc_minutes= val.min_ones + val.min_tens * 10; - if ((rtc_minutes < real_minutes - ? real_minutes - rtc_minutes - : rtc_minutes - real_minutes) < 30) - { - val.sec_ones = real_seconds % 10; - val.sec_tens = real_seconds / 10; - val.min_ones = real_minutes % 10; - val.min_tens = real_minutes / 10; - mste_write(&val); - } - else - return -1; - return 0; -} - -int atari_tt_set_clock_mmss (unsigned long nowtime) -{ - int retval = 0; - short real_seconds = nowtime % 60, real_minutes = (nowtime / 60) % 60; - unsigned char save_control, save_freq_select, rtc_minutes; - - save_control = RTC_READ (RTC_CONTROL); /* tell the clock it's being set */ - RTC_WRITE (RTC_CONTROL, save_control | RTC_SET); - - save_freq_select = RTC_READ (RTC_FREQ_SELECT); /* stop and reset prescaler */ - RTC_WRITE (RTC_FREQ_SELECT, save_freq_select | RTC_DIV_RESET2); - - rtc_minutes = RTC_READ (RTC_MINUTES); - if (!(save_control & RTC_DM_BINARY)) - rtc_minutes = bcd2bin(rtc_minutes); - - /* Since we're only adjusting minutes and seconds, don't interfere - with hour overflow. This avoids messing with unknown time zones - but requires your RTC not to be off by more than 30 minutes. */ - if ((rtc_minutes < real_minutes - ? real_minutes - rtc_minutes - : rtc_minutes - real_minutes) < 30) - { - if (!(save_control & RTC_DM_BINARY)) - { - real_seconds = bin2bcd(real_seconds); - real_minutes = bin2bcd(real_minutes); - } - RTC_WRITE (RTC_SECONDS, real_seconds); - RTC_WRITE (RTC_MINUTES, real_minutes); - } - else - retval = -1; - - RTC_WRITE (RTC_FREQ_SELECT, save_freq_select); - RTC_WRITE (RTC_CONTROL, save_control); - return retval; -} - -/* - * Local variables: - * c-indent-level: 4 - * tab-width: 8 - * End: - */ |