diff options
Diffstat (limited to 'arch/powerpc/kernel/rtas-rtc.c')
-rw-r--r-- | arch/powerpc/kernel/rtas-rtc.c | 105 |
1 files changed, 105 insertions, 0 deletions
diff --git a/arch/powerpc/kernel/rtas-rtc.c b/arch/powerpc/kernel/rtas-rtc.c new file mode 100644 index 00000000000..7b948662704 --- /dev/null +++ b/arch/powerpc/kernel/rtas-rtc.c @@ -0,0 +1,105 @@ +#include <linux/kernel.h> +#include <linux/time.h> +#include <linux/timer.h> +#include <linux/init.h> +#include <linux/rtc.h> +#include <linux/delay.h> +#include <asm/prom.h> +#include <asm/rtas.h> +#include <asm/time.h> + + +#define MAX_RTC_WAIT 5000 /* 5 sec */ +#define RTAS_CLOCK_BUSY (-2) +unsigned long __init rtas_get_boot_time(void) +{ + int ret[8]; + int error, wait_time; + unsigned long max_wait_tb; + + max_wait_tb = get_tb() + tb_ticks_per_usec * 1000 * MAX_RTC_WAIT; + do { + error = rtas_call(rtas_token("get-time-of-day"), 0, 8, ret); + if (error == RTAS_CLOCK_BUSY || rtas_is_extended_busy(error)) { + wait_time = rtas_extended_busy_delay_time(error); + /* This is boot time so we spin. */ + udelay(wait_time*1000); + error = RTAS_CLOCK_BUSY; + } + } while (error == RTAS_CLOCK_BUSY && (get_tb() < max_wait_tb)); + + if (error != 0 && printk_ratelimit()) { + printk(KERN_WARNING "error: reading the clock failed (%d)\n", + error); + return 0; + } + + return mktime(ret[0], ret[1], ret[2], ret[3], ret[4], ret[5]); +} + +/* NOTE: get_rtc_time will get an error if executed in interrupt context + * and if a delay is needed to read the clock. In this case we just + * silently return without updating rtc_tm. + */ +void rtas_get_rtc_time(struct rtc_time *rtc_tm) +{ + int ret[8]; + int error, wait_time; + unsigned long max_wait_tb; + + max_wait_tb = get_tb() + tb_ticks_per_usec * 1000 * MAX_RTC_WAIT; + do { + error = rtas_call(rtas_token("get-time-of-day"), 0, 8, ret); + if (error == RTAS_CLOCK_BUSY || rtas_is_extended_busy(error)) { + if (in_interrupt() && printk_ratelimit()) { + memset(&rtc_tm, 0, sizeof(struct rtc_time)); + printk(KERN_WARNING "error: reading clock" + " would delay interrupt\n"); + return; /* delay not allowed */ + } + wait_time = rtas_extended_busy_delay_time(error); + msleep(wait_time); + error = RTAS_CLOCK_BUSY; + } + } while (error == RTAS_CLOCK_BUSY && (get_tb() < max_wait_tb)); + + if (error != 0 && printk_ratelimit()) { + printk(KERN_WARNING "error: reading the clock failed (%d)\n", + error); + return; + } + + rtc_tm->tm_sec = ret[5]; + rtc_tm->tm_min = ret[4]; + rtc_tm->tm_hour = ret[3]; + rtc_tm->tm_mday = ret[2]; + rtc_tm->tm_mon = ret[1] - 1; + rtc_tm->tm_year = ret[0] - 1900; +} + +int rtas_set_rtc_time(struct rtc_time *tm) +{ + int error, wait_time; + unsigned long max_wait_tb; + + max_wait_tb = get_tb() + tb_ticks_per_usec * 1000 * MAX_RTC_WAIT; + do { + error = rtas_call(rtas_token("set-time-of-day"), 7, 1, NULL, + tm->tm_year + 1900, tm->tm_mon + 1, + tm->tm_mday, tm->tm_hour, tm->tm_min, + tm->tm_sec, 0); + if (error == RTAS_CLOCK_BUSY || rtas_is_extended_busy(error)) { + if (in_interrupt()) + return 1; /* probably decrementer */ + wait_time = rtas_extended_busy_delay_time(error); + msleep(wait_time); + error = RTAS_CLOCK_BUSY; + } + } while (error == RTAS_CLOCK_BUSY && (get_tb() < max_wait_tb)); + + if (error != 0 && printk_ratelimit()) + printk(KERN_WARNING "error: setting the clock failed (%d)\n", + error); + + return 0; +} |