+++ /dev/null
-/*
- * DS1286 Real Time Clock interface for Linux
- *
- * Copyright (C) 1998, 1999, 2000 Ralf Baechle
- *
- * Based on code written by Paul Gortmaker.
- *
- * This driver allows use of the real time clock (built into nearly all
- * computers) from user space. It exports the /dev/rtc interface supporting
- * various ioctl() and also the /proc/rtc pseudo-file for status
- * information.
- *
- * The ioctls can be used to set the interrupt behaviour and generation rate
- * from the RTC via IRQ 8. Then the /dev/rtc interface can be used to make
- * use of these timer interrupts, be they interval or alarm based.
- *
- * The /dev/rtc interface will block on reads until an interrupt has been
- * received. If a RTC interrupt has already happened, it will output an
- * unsigned long and then block. The output value contains the interrupt
- * status in the low byte and the number of interrupts since the last read
- * in the remaining high bytes. The /dev/rtc interface can also be used with
- * the select(2) call.
- *
- * 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.
- */
-#include <linux/ds1286.h>
-#include <linux/smp_lock.h>
-#include <linux/types.h>
-#include <linux/errno.h>
-#include <linux/miscdevice.h>
-#include <linux/slab.h>
-#include <linux/ioport.h>
-#include <linux/fcntl.h>
-#include <linux/init.h>
-#include <linux/poll.h>
-#include <linux/rtc.h>
-#include <linux/spinlock.h>
-#include <linux/bcd.h>
-#include <linux/proc_fs.h>
-#include <linux/jiffies.h>
-
-#include <asm/uaccess.h>
-#include <asm/system.h>
-
-#define DS1286_VERSION "1.0"
-
-/*
- * 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 DECLARE_WAIT_QUEUE_HEAD(ds1286_wait);
-
-static ssize_t ds1286_read(struct file *file, char *buf,
- size_t count, loff_t *ppos);
-
-static int ds1286_ioctl(struct inode *inode, struct file *file,
- unsigned int cmd, unsigned long arg);
-
-static unsigned int ds1286_poll(struct file *file, poll_table *wait);
-
-static void ds1286_get_alm_time (struct rtc_time *alm_tm);
-static void ds1286_get_time(struct rtc_time *rtc_tm);
-static int ds1286_set_time(struct rtc_time *rtc_tm);
-
-static inline unsigned char ds1286_is_updating(void);
-
-static DEFINE_SPINLOCK(ds1286_lock);
-
-static int ds1286_read_proc(char *page, char **start, off_t off,
- int count, int *eof, void *data);
-
-/*
- * Bits in rtc_status. (7 bits of room for future expansion)
- */
-
-#define RTC_IS_OPEN 0x01 /* means /dev/rtc is in use */
-#define RTC_TIMER_ON 0x02 /* missed irq timer active */
-
-static unsigned char ds1286_status; /* bitmapped status byte. */
-
-static 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 ds1286_read(struct file *file, char *buf,
- size_t count, loff_t *ppos)
-{
- return -EIO;
-}
-
-static int ds1286_ioctl(struct inode *inode, struct file *file,
- unsigned int cmd, unsigned long arg)
-{
- struct rtc_time wtime;
-
- switch (cmd) {
- case RTC_AIE_OFF: /* Mask alarm int. enab. bit */
- {
- unsigned long flags;
- unsigned char val;
-
- if (!capable(CAP_SYS_TIME))
- return -EACCES;
-
- spin_lock_irqsave(&ds1286_lock, flags);
- val = rtc_read(RTC_CMD);
- val |= RTC_TDM;
- rtc_write(val, RTC_CMD);
- spin_unlock_irqrestore(&ds1286_lock, flags);
-
- return 0;
- }
- case RTC_AIE_ON: /* Allow alarm interrupts. */
- {
- unsigned long flags;
- unsigned char val;
-
- if (!capable(CAP_SYS_TIME))
- return -EACCES;
-
- spin_lock_irqsave(&ds1286_lock, flags);
- val = rtc_read(RTC_CMD);
- val &= ~RTC_TDM;
- rtc_write(val, RTC_CMD);
- spin_unlock_irqrestore(&ds1286_lock, flags);
-
- return 0;
- }
- case RTC_WIE_OFF: /* Mask watchdog int. enab. bit */
- {
- unsigned long flags;
- unsigned char val;
-
- if (!capable(CAP_SYS_TIME))
- return -EACCES;
-
- spin_lock_irqsave(&ds1286_lock, flags);
- val = rtc_read(RTC_CMD);
- val |= RTC_WAM;
- rtc_write(val, RTC_CMD);
- spin_unlock_irqrestore(&ds1286_lock, flags);
-
- return 0;
- }
- case RTC_WIE_ON: /* Allow watchdog interrupts. */
- {
- unsigned long flags;
- unsigned char val;
-
- if (!capable(CAP_SYS_TIME))
- return -EACCES;
-
- spin_lock_irqsave(&ds1286_lock, flags);
- val = rtc_read(RTC_CMD);
- val &= ~RTC_WAM;
- rtc_write(val, RTC_CMD);
- spin_unlock_irqrestore(&ds1286_lock, flags);
-
- return 0;
- }
- case RTC_ALM_READ: /* Read the present alarm time */
- {
- /*
- * This returns a struct rtc_time. Reading >= 0xc0
- * means "don't care" or "match all". Only the tm_hour,
- * tm_min, and tm_sec values are filled in.
- */
-
- memset(&wtime, 0, sizeof(wtime));
- ds1286_get_alm_time(&wtime);
- break;
- }
- case RTC_ALM_SET: /* Store a time into the alarm */
- {
- /*
- * This expects a struct rtc_time. Writing 0xff means
- * "don't care" or "match all". Only the tm_hour,
- * tm_min and tm_sec are used.
- */
- unsigned char hrs, min, sec;
- struct rtc_time alm_tm;
-
- if (!capable(CAP_SYS_TIME))
- return -EACCES;
-
- if (copy_from_user(&alm_tm, (struct rtc_time*)arg,
- sizeof(struct rtc_time)))
- return -EFAULT;
-
- hrs = alm_tm.tm_hour;
- min = alm_tm.tm_min;
- sec = alm_tm.tm_sec;
-
- if (hrs >= 24)
- hrs = 0xff;
-
- if (min >= 60)
- min = 0xff;
-
- if (sec != 0)
- return -EINVAL;
-
- min = bin2bcd(min);
- min = bin2bcd(hrs);
-
- spin_lock(&ds1286_lock);
- rtc_write(hrs, RTC_HOURS_ALARM);
- rtc_write(min, RTC_MINUTES_ALARM);
- spin_unlock(&ds1286_lock);
-
- return 0;
- }
- case RTC_RD_TIME: /* Read the time/date from RTC */
- {
- memset(&wtime, 0, sizeof(wtime));
- ds1286_get_time(&wtime);
- break;
- }
- case RTC_SET_TIME: /* Set the RTC */
- {
- struct rtc_time rtc_tm;
-
- if (!capable(CAP_SYS_TIME))
- return -EACCES;
-
- if (copy_from_user(&rtc_tm, (struct rtc_time*)arg,
- sizeof(struct rtc_time)))
- return -EFAULT;
-
- return ds1286_set_time(&rtc_tm);
- }
- default:
- return -EINVAL;
- }
- return copy_to_user((void *)arg, &wtime, sizeof wtime) ? -EFAULT : 0;
-}
-
-/*
- * We enforce only one user at a time here with the open/close.
- * Also clear the previous interrupt data on an open, and clean
- * up things on a close.
- */
-
-static int ds1286_open(struct inode *inode, struct file *file)
-{
- lock_kernel();
- spin_lock_irq(&ds1286_lock);
-
- if (ds1286_status & RTC_IS_OPEN)
- goto out_busy;
-
- ds1286_status |= RTC_IS_OPEN;
-
- spin_unlock_irq(&ds1286_lock);
- unlock_kernel();
- return 0;
-
-out_busy:
- spin_lock_irq(&ds1286_lock);
- unlock_kernel();
- return -EBUSY;
-}
-
-static int ds1286_release(struct inode *inode, struct file *file)
-{
- ds1286_status &= ~RTC_IS_OPEN;
-
- return 0;
-}
-
-static unsigned int ds1286_poll(struct file *file, poll_table *wait)
-{
- poll_wait(file, &ds1286_wait, wait);
-
- return 0;
-}
-
-/*
- * The various file operations we support.
- */
-
-static const struct file_operations ds1286_fops = {
- .llseek = no_llseek,
- .read = ds1286_read,
- .poll = ds1286_poll,
- .ioctl = ds1286_ioctl,
- .open = ds1286_open,
- .release = ds1286_release,
-};
-
-static struct miscdevice ds1286_dev=
-{
- .minor = RTC_MINOR,
- .name = "rtc",
- .fops = &ds1286_fops,
-};
-
-static int __init ds1286_init(void)
-{
- int err;
-
- printk(KERN_INFO "DS1286 Real Time Clock Driver v%s\n", DS1286_VERSION);
-
- err = misc_register(&ds1286_dev);
- if (err)
- goto out;
-
- if (!create_proc_read_entry("driver/rtc", 0, 0, ds1286_read_proc, NULL)) {
- err = -ENOMEM;
-
- goto out_deregister;
- }
-
- return 0;
-
-out_deregister:
- misc_deregister(&ds1286_dev);
-
-out:
- return err;
-}
-
-static void __exit ds1286_exit(void)
-{
- remove_proc_entry("driver/rtc", NULL);
- misc_deregister(&ds1286_dev);
-}
-
-static char *days[] = {
- "***", "Sun", "Mon", "Tue", "Wed", "Thu", "Fri", "Sat"
-};
-
-/*
- * Info exported via "/proc/rtc".
- */
-static int ds1286_proc_output(char *buf)
-{
- char *p, *s;
- struct rtc_time tm;
- unsigned char hundredth, month, cmd, amode;
-
- p = buf;
-
- ds1286_get_time(&tm);
- hundredth = rtc_read(RTC_HUNDREDTH_SECOND);
- hundredth = bcd2bin(hundredth);
-
- p += sprintf(p,
- "rtc_time\t: %02d:%02d:%02d.%02d\n"
- "rtc_date\t: %04d-%02d-%02d\n",
- tm.tm_hour, tm.tm_min, tm.tm_sec, hundredth,
- tm.tm_year + 1900, tm.tm_mon + 1, tm.tm_mday);
-
- /*
- * We implicitly assume 24hr mode here. Alarm values >= 0xc0 will
- * match any value for that particular field. Values that are
- * greater than a valid time, but less than 0xc0 shouldn't appear.
- */
- ds1286_get_alm_time(&tm);
- p += sprintf(p, "alarm\t\t: %s ", days[tm.tm_wday]);
- if (tm.tm_hour <= 24)
- p += sprintf(p, "%02d:", tm.tm_hour);
- else
- p += sprintf(p, "**:");
-
- if (tm.tm_min <= 59)
- p += sprintf(p, "%02d\n", tm.tm_min);
- else
- p += sprintf(p, "**\n");
-
- month = rtc_read(RTC_MONTH);
- p += sprintf(p,
- "oscillator\t: %s\n"
- "square_wave\t: %s\n",
- (month & RTC_EOSC) ? "disabled" : "enabled",
- (month & RTC_ESQW) ? "disabled" : "enabled");
-
- amode = ((rtc_read(RTC_MINUTES_ALARM) & 0x80) >> 5) |
- ((rtc_read(RTC_HOURS_ALARM) & 0x80) >> 6) |
- ((rtc_read(RTC_DAY_ALARM) & 0x80) >> 7);
- if (amode == 7) s = "each minute";
- else if (amode == 3) s = "minutes match";
- else if (amode == 1) s = "hours and minutes match";
- else if (amode == 0) s = "days, hours and minutes match";
- else s = "invalid";
- p += sprintf(p, "alarm_mode\t: %s\n", s);
-
- cmd = rtc_read(RTC_CMD);
- p += sprintf(p,
- "alarm_enable\t: %s\n"
- "wdog_alarm\t: %s\n"
- "alarm_mask\t: %s\n"
- "wdog_alarm_mask\t: %s\n"
- "interrupt_mode\t: %s\n"
- "INTB_mode\t: %s_active\n"
- "interrupt_pins\t: %s\n",
- (cmd & RTC_TDF) ? "yes" : "no",
- (cmd & RTC_WAF) ? "yes" : "no",
- (cmd & RTC_TDM) ? "disabled" : "enabled",
- (cmd & RTC_WAM) ? "disabled" : "enabled",
- (cmd & RTC_PU_LVL) ? "pulse" : "level",
- (cmd & RTC_IBH_LO) ? "low" : "high",
- (cmd & RTC_IPSW) ? "unswapped" : "swapped");
-
- return p - buf;
-}
-
-static int ds1286_read_proc(char *page, char **start, off_t off,
- int count, int *eof, void *data)
-{
- int len = ds1286_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;
-}
-
-/*
- * Returns true if a clock update is in progress
- */
-static inline unsigned char ds1286_is_updating(void)
-{
- return rtc_read(RTC_CMD) & RTC_TE;
-}
-
-
-static void ds1286_get_time(struct rtc_time *rtc_tm)
-{
- unsigned char save_control;
- unsigned long flags;
-
- /*
- * read RTC once any update in progress is done. The update
- * can take just over 2ms. We wait 10 to 20ms. There is no need to
- * to poll-wait (up to 1s - eeccch) for the falling edge of RTC_UIP.
- * If you need to know *exactly* when a second has started, enable
- * periodic update complete interrupts, (via ioctl) and then
- * immediately read /dev/rtc which will block until you get the IRQ.
- * Once the read clears, read the RTC time (again via ioctl). Easy.
- */
-
- if (ds1286_is_updating() != 0)
- msleep(20);
-
- /*
- * Only the values that we read from the RTC are set. We leave
- * tm_wday, tm_yday and tm_isdst untouched. Even though the
- * RTC has RTC_DAY_OF_WEEK, we ignore it, as it is only updated
- * by the RTC when initially set to a non-zero value.
- */
- spin_lock_irqsave(&ds1286_lock, flags);
- save_control = rtc_read(RTC_CMD);
- rtc_write((save_control|RTC_TE), RTC_CMD);
-
- rtc_tm->tm_sec = rtc_read(RTC_SECONDS);
- rtc_tm->tm_min = rtc_read(RTC_MINUTES);
- rtc_tm->tm_hour = rtc_read(RTC_HOURS) & 0x3f;
- rtc_tm->tm_mday = rtc_read(RTC_DATE);
- rtc_tm->tm_mon = rtc_read(RTC_MONTH) & 0x1f;
- rtc_tm->tm_year = rtc_read(RTC_YEAR);
-
- rtc_write(save_control, RTC_CMD);
- spin_unlock_irqrestore(&ds1286_lock, flags);
-
- rtc_tm->tm_sec = bcd2bin(rtc_tm->tm_sec);
- rtc_tm->tm_min = bcd2bin(rtc_tm->tm_min);
- rtc_tm->tm_hour = bcd2bin(rtc_tm->tm_hour);
- rtc_tm->tm_mday = bcd2bin(rtc_tm->tm_mday);
- rtc_tm->tm_mon = bcd2bin(rtc_tm->tm_mon);
- rtc_tm->tm_year = bcd2bin(rtc_tm->tm_year);
-
- /*
- * Account for differences between how the RTC uses the values
- * and how they are defined in a struct rtc_time;
- */
- if (rtc_tm->tm_year < 45)
- rtc_tm->tm_year += 30;
- if ((rtc_tm->tm_year += 40) < 70)
- rtc_tm->tm_year += 100;
-
- rtc_tm->tm_mon--;
-}
-
-static int ds1286_set_time(struct rtc_time *rtc_tm)
-{
- unsigned char mon, day, hrs, min, sec, leap_yr;
- unsigned char save_control;
- unsigned int yrs;
- unsigned long flags;
-
-
- yrs = rtc_tm->tm_year + 1900;
- 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 < 1970)
- 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 -= 1940) > 255) /* They are unsigned */
- return -EINVAL;
-
- if (yrs >= 100)
- yrs -= 100;
-
- sec = bin2bcd(sec);
- min = bin2bcd(min);
- hrs = bin2bcd(hrs);
- day = bin2bcd(day);
- mon = bin2bcd(mon);
- yrs = bin2bcd(yrs);
-
- spin_lock_irqsave(&ds1286_lock, flags);
- save_control = rtc_read(RTC_CMD);
- rtc_write((save_control|RTC_TE), RTC_CMD);
-
- rtc_write(yrs, RTC_YEAR);
- rtc_write(mon, RTC_MONTH);
- rtc_write(day, RTC_DATE);
- rtc_write(hrs, RTC_HOURS);
- rtc_write(min, RTC_MINUTES);
- rtc_write(sec, RTC_SECONDS);
- rtc_write(0, RTC_HUNDREDTH_SECOND);
-
- rtc_write(save_control, RTC_CMD);
- spin_unlock_irqrestore(&ds1286_lock, flags);
-
- return 0;
-}
-
-static void ds1286_get_alm_time(struct rtc_time *alm_tm)
-{
- unsigned char cmd;
- unsigned long flags;
-
- /*
- * Only the values that we read from the RTC are set. That
- * means only tm_wday, tm_hour, tm_min.
- */
- spin_lock_irqsave(&ds1286_lock, flags);
- alm_tm->tm_min = rtc_read(RTC_MINUTES_ALARM) & 0x7f;
- alm_tm->tm_hour = rtc_read(RTC_HOURS_ALARM) & 0x1f;
- alm_tm->tm_wday = rtc_read(RTC_DAY_ALARM) & 0x07;
- cmd = rtc_read(RTC_CMD);
- spin_unlock_irqrestore(&ds1286_lock, flags);
-
- alm_tm->tm_min = bcd2bin(alm_tm->tm_min);
- alm_tm->tm_hour = bcd2bin(alm_tm->tm_hour);
- alm_tm->tm_sec = 0;
-}
-
-module_init(ds1286_init);
-module_exit(ds1286_exit);
-
-MODULE_AUTHOR("Ralf Baechle");
-MODULE_LICENSE("GPL");
-MODULE_ALIAS_MISCDEV(RTC_MINOR);
projects / GitHub / LineageOS / android_kernel_motorola_exynos9610.git / commitdiff