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