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-rw-r--r--arch/ppc64/kernel/rtc.c440
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 00000000000..3e70b91375f
--- /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
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