diff options
Diffstat (limited to 'arch/ppc64/kernel/rtc.c')
| -rw-r--r-- | arch/ppc64/kernel/rtc.c | 440 |
1 files changed, 440 insertions, 0 deletions
diff --git a/arch/ppc64/kernel/rtc.c b/arch/ppc64/kernel/rtc.c new file mode 100644 index 000000000000..3e70b91375fc --- /dev/null +++ b/arch/ppc64/kernel/rtc.c @@ -0,0 +1,440 @@ +/* + * Real Time Clock interface for PPC64. + * + * Based on rtc.c by Paul Gortmaker + * + * This driver allows use of the real time clock + * from user space. It exports the /dev/rtc + * interface supporting various ioctl() and also the + * /proc/driver/rtc pseudo-file for status information. + * + * Interface does not support RTC interrupts nor an alarm. + * + * 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. + * + * 1.0 Mike Corrigan: IBM iSeries rtc support + * 1.1 Dave Engebretsen: IBM pSeries rtc support + */ + +#define RTC_VERSION "1.1" + +#include <linux/config.h> +#include <linux/module.h> +#include <linux/kernel.h> +#include <linux/types.h> +#include <linux/miscdevice.h> +#include <linux/ioport.h> +#include <linux/fcntl.h> +#include <linux/mc146818rtc.h> +#include <linux/init.h> +#include <linux/poll.h> +#include <linux/proc_fs.h> +#include <linux/spinlock.h> +#include <linux/bcd.h> +#include <linux/interrupt.h> + +#include <asm/io.h> +#include <asm/uaccess.h> +#include <asm/system.h> +#include <asm/time.h> +#include <asm/rtas.h> + +#include <asm/iSeries/LparData.h> +#include <asm/iSeries/mf.h> +#include <asm/machdep.h> +#include <asm/iSeries/ItSpCommArea.h> + +extern int piranha_simulator; + +/* + * We sponge a minor off of the misc major. No need slurping + * up another valuable major dev number for this. If you add + * an ioctl, make sure you don't conflict with SPARC's RTC + * ioctls. + */ + +static ssize_t rtc_read(struct file *file, char __user *buf, + size_t count, loff_t *ppos); + +static int rtc_ioctl(struct inode *inode, struct file *file, + unsigned int cmd, unsigned long arg); + +static int rtc_read_proc(char *page, char **start, off_t off, + int count, int *eof, void *data); + +/* + * If this driver ever becomes modularised, it will be really nice + * to make the epoch retain its value across module reload... + */ + +static unsigned long epoch = 1900; /* year corresponding to 0x00 */ + +static const unsigned char days_in_mo[] = +{0, 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31}; + +/* + * Now all the various file operations that we export. + */ + +static ssize_t rtc_read(struct file *file, char __user *buf, + size_t count, loff_t *ppos) +{ + return -EIO; +} + +static int rtc_ioctl(struct inode *inode, struct file *file, unsigned int cmd, + unsigned long arg) +{ + struct rtc_time wtime; + + switch (cmd) { + case RTC_RD_TIME: /* Read the time/date from RTC */ + { + memset(&wtime, 0, sizeof(struct rtc_time)); + ppc_md.get_rtc_time(&wtime); + break; + } + case RTC_SET_TIME: /* Set the RTC */ + { + struct rtc_time rtc_tm; + unsigned char mon, day, hrs, min, sec, leap_yr; + unsigned int yrs; + + if (!capable(CAP_SYS_TIME)) + return -EACCES; + + if (copy_from_user(&rtc_tm, (struct rtc_time __user *)arg, + sizeof(struct rtc_time))) + return -EFAULT; + + yrs = rtc_tm.tm_year; + mon = rtc_tm.tm_mon + 1; /* tm_mon starts at zero */ + day = rtc_tm.tm_mday; + hrs = rtc_tm.tm_hour; + min = rtc_tm.tm_min; + sec = rtc_tm.tm_sec; + + if (yrs < 70) + return -EINVAL; + + leap_yr = ((!(yrs % 4) && (yrs % 100)) || !(yrs % 400)); + + if ((mon > 12) || (day == 0)) + return -EINVAL; + + if (day > (days_in_mo[mon] + ((mon == 2) && leap_yr))) + return -EINVAL; + + if ((hrs >= 24) || (min >= 60) || (sec >= 60)) + return -EINVAL; + + if ( yrs > 169 ) + return -EINVAL; + + ppc_md.set_rtc_time(&rtc_tm); + + return 0; + } + case RTC_EPOCH_READ: /* Read the epoch. */ + { + return put_user (epoch, (unsigned long __user *)arg); + } + case RTC_EPOCH_SET: /* Set the epoch. */ + { + /* + * There were no RTC clocks before 1900. + */ + if (arg < 1900) + return -EINVAL; + + if (!capable(CAP_SYS_TIME)) + return -EACCES; + + epoch = arg; + return 0; + } + default: + return -EINVAL; + } + return copy_to_user((void __user *)arg, &wtime, sizeof wtime) ? -EFAULT : 0; +} + +static int rtc_open(struct inode *inode, struct file *file) +{ + nonseekable_open(inode, file); + return 0; +} + +static int rtc_release(struct inode *inode, struct file *file) +{ + return 0; +} + +/* + * The various file operations we support. + */ +static struct file_operations rtc_fops = { + .owner = THIS_MODULE, + .llseek = no_llseek, + .read = rtc_read, + .ioctl = rtc_ioctl, + .open = rtc_open, + .release = rtc_release, +}; + +static struct miscdevice rtc_dev = { + .minor = RTC_MINOR, + .name = "rtc", + .fops = &rtc_fops +}; + +static int __init rtc_init(void) +{ + int retval; + + retval = misc_register(&rtc_dev); + if(retval < 0) + return retval; + +#ifdef CONFIG_PROC_FS + if (create_proc_read_entry("driver/rtc", 0, NULL, rtc_read_proc, NULL) + == NULL) { + misc_deregister(&rtc_dev); + return -ENOMEM; + } +#endif + + printk(KERN_INFO "i/pSeries Real Time Clock Driver v" RTC_VERSION "\n"); + + return 0; +} + +static void __exit rtc_exit (void) +{ + remove_proc_entry ("driver/rtc", NULL); + misc_deregister(&rtc_dev); +} + +module_init(rtc_init); +module_exit(rtc_exit); + +/* + * Info exported via "/proc/driver/rtc". + */ + +static int rtc_proc_output (char *buf) +{ + + char *p; + struct rtc_time tm; + + p = buf; + + ppc_md.get_rtc_time(&tm); + + /* + * There is no way to tell if the luser has the RTC set for local + * time or for Universal Standard Time (GMT). Probably local though. + */ + p += sprintf(p, + "rtc_time\t: %02d:%02d:%02d\n" + "rtc_date\t: %04d-%02d-%02d\n" + "rtc_epoch\t: %04lu\n", + tm.tm_hour, tm.tm_min, tm.tm_sec, + tm.tm_year + 1900, tm.tm_mon + 1, tm.tm_mday, epoch); + + p += sprintf(p, + "DST_enable\t: no\n" + "BCD\t\t: yes\n" + "24hr\t\t: yes\n" ); + + return p - buf; +} + +static int rtc_read_proc(char *page, char **start, off_t off, + int count, int *eof, void *data) +{ + int len = rtc_proc_output (page); + if (len <= off+count) *eof = 1; + *start = page + off; + len -= off; + if (len>count) len = count; + if (len<0) len = 0; + return len; +} + +#ifdef CONFIG_PPC_ISERIES +/* + * Get the RTC from the virtual service processor + * This requires flowing LpEvents to the primary partition + */ +void iSeries_get_rtc_time(struct rtc_time *rtc_tm) +{ + if (piranha_simulator) + return; + + mf_get_rtc(rtc_tm); + rtc_tm->tm_mon--; +} + +/* + * Set the RTC in the virtual service processor + * This requires flowing LpEvents to the primary partition + */ +int iSeries_set_rtc_time(struct rtc_time *tm) +{ + mf_set_rtc(tm); + return 0; +} + +void iSeries_get_boot_time(struct rtc_time *tm) +{ + unsigned long time; + static unsigned long lastsec = 1; + + u32 dataWord1 = *((u32 *)(&xSpCommArea.xBcdTimeAtIplStart)); + u32 dataWord2 = *(((u32 *)&(xSpCommArea.xBcdTimeAtIplStart)) + 1); + int year = 1970; + int year1 = ( dataWord1 >> 24 ) & 0x000000FF; + int year2 = ( dataWord1 >> 16 ) & 0x000000FF; + int sec = ( dataWord1 >> 8 ) & 0x000000FF; + int min = dataWord1 & 0x000000FF; + int hour = ( dataWord2 >> 24 ) & 0x000000FF; + int day = ( dataWord2 >> 8 ) & 0x000000FF; + int mon = dataWord2 & 0x000000FF; + + if ( piranha_simulator ) + return; + + BCD_TO_BIN(sec); + BCD_TO_BIN(min); + BCD_TO_BIN(hour); + BCD_TO_BIN(day); + BCD_TO_BIN(mon); + BCD_TO_BIN(year1); + BCD_TO_BIN(year2); + year = year1 * 100 + year2; + + time = mktime(year, mon, day, hour, min, sec); + time += ( jiffies / HZ ); + + /* Now THIS is a nasty hack! + * It ensures that the first two calls get different answers. + * That way the loop in init_time (time.c) will not think + * the clock is stuck. + */ + if ( lastsec ) { + time -= lastsec; + --lastsec; + } + + to_tm(time, tm); + tm->tm_year -= 1900; + tm->tm_mon -= 1; +} +#endif + +#ifdef CONFIG_PPC_RTAS +#define MAX_RTC_WAIT 5000 /* 5 sec */ +#define RTAS_CLOCK_BUSY (-2) +void pSeries_get_boot_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)) { + 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; + } + + 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; +} + +/* 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 pSeries_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()) { + printk(KERN_WARNING "error: reading clock would delay interrupt\n"); + return; /* delay not allowed */ + } + wait_time = rtas_extended_busy_delay_time(error); + set_current_state(TASK_INTERRUPTIBLE); + schedule_timeout(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 pSeries_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); + set_current_state(TASK_INTERRUPTIBLE); + schedule_timeout(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; +} +#endif |