diff options
Diffstat (limited to 'drivers/char/rtc.c')
| -rw-r--r-- | drivers/char/rtc.c | 1311 |
1 files changed, 0 insertions, 1311 deletions
diff --git a/drivers/char/rtc.c b/drivers/char/rtc.c deleted file mode 100644 index 3b91184b77ae..000000000000 --- a/drivers/char/rtc.c +++ /dev/null @@ -1,1311 +0,0 @@ -// SPDX-License-Identifier: GPL-2.0-or-later -/* - * Real Time Clock interface for Linux - * - * Copyright (C) 1996 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/driver/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. - * - * Based on other minimal char device drivers, like Alan's - * watchdog, Ted's random, etc. etc. - * - * 1.07 Paul Gortmaker. - * 1.08 Miquel van Smoorenburg: disallow certain things on the - * DEC Alpha as the CMOS clock is also used for other things. - * 1.09 Nikita Schmidt: epoch support and some Alpha cleanup. - * 1.09a Pete Zaitcev: Sun SPARC - * 1.09b Jeff Garzik: Modularize, init cleanup - * 1.09c Jeff Garzik: SMP cleanup - * 1.10 Paul Barton-Davis: add support for async I/O - * 1.10a Andrea Arcangeli: Alpha updates - * 1.10b Andrew Morton: SMP lock fix - * 1.10c Cesar Barros: SMP locking fixes and cleanup - * 1.10d Paul Gortmaker: delete paranoia check in rtc_exit - * 1.10e Maciej W. Rozycki: Handle DECstation's year weirdness. - * 1.11 Takashi Iwai: Kernel access functions - * rtc_register/rtc_unregister/rtc_control - * 1.11a Daniele Bellucci: Audit create_proc_read_entry in rtc_init - * 1.12 Venkatesh Pallipadi: Hooks for emulating rtc on HPET base-timer - * CONFIG_HPET_EMULATE_RTC - * 1.12a Maciej W. Rozycki: Handle memory-mapped chips properly. - * 1.12ac Alan Cox: Allow read access to the day of week register - * 1.12b David John: Remove calls to the BKL. - */ - -#define RTC_VERSION "1.12b" - -/* - * Note that *all* calls to CMOS_READ and CMOS_WRITE are done with - * interrupts disabled. Due to the index-port/data-port (0x70/0x71) - * design of the RTC, we don't want two different things trying to - * get to it at once. (e.g. the periodic 11 min sync from - * kernel/time/ntp.c vs. this driver.) - */ - -#include <linux/interrupt.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/seq_file.h> -#include <linux/spinlock.h> -#include <linux/sched/signal.h> -#include <linux/sysctl.h> -#include <linux/wait.h> -#include <linux/bcd.h> -#include <linux/delay.h> -#include <linux/uaccess.h> -#include <linux/ratelimit.h> - -#include <asm/current.h> - -#ifdef CONFIG_X86 -#include <asm/hpet.h> -#endif - -#ifdef CONFIG_SPARC32 -#include <linux/of.h> -#include <linux/of_device.h> -#include <asm/io.h> - -static unsigned long rtc_port; -static int rtc_irq; -#endif - -#ifdef CONFIG_HPET_EMULATE_RTC -#undef RTC_IRQ -#endif - -#ifdef RTC_IRQ -static int rtc_has_irq = 1; -#endif - -#ifndef CONFIG_HPET_EMULATE_RTC -#define is_hpet_enabled() 0 -#define hpet_set_alarm_time(hrs, min, sec) 0 -#define hpet_set_periodic_freq(arg) 0 -#define hpet_mask_rtc_irq_bit(arg) 0 -#define hpet_set_rtc_irq_bit(arg) 0 -#define hpet_rtc_timer_init() do { } while (0) -#define hpet_rtc_dropped_irq() 0 -#define hpet_register_irq_handler(h) ({ 0; }) -#define hpet_unregister_irq_handler(h) ({ 0; }) -#ifdef RTC_IRQ -static irqreturn_t hpet_rtc_interrupt(int irq, void *dev_id) -{ - return 0; -} -#endif -#endif - -/* - * 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 struct fasync_struct *rtc_async_queue; - -static DECLARE_WAIT_QUEUE_HEAD(rtc_wait); - -#ifdef RTC_IRQ -static void rtc_dropped_irq(struct timer_list *unused); - -static DEFINE_TIMER(rtc_irq_timer, rtc_dropped_irq); -#endif - -static ssize_t rtc_read(struct file *file, char __user *buf, - size_t count, loff_t *ppos); - -static long rtc_ioctl(struct file *file, unsigned int cmd, unsigned long arg); -static void rtc_get_rtc_time(struct rtc_time *rtc_tm); - -#ifdef RTC_IRQ -static __poll_t rtc_poll(struct file *file, poll_table *wait); -#endif - -static void get_rtc_alm_time(struct rtc_time *alm_tm); -#ifdef RTC_IRQ -static void set_rtc_irq_bit_locked(unsigned char bit); -static void mask_rtc_irq_bit_locked(unsigned char bit); - -static inline void set_rtc_irq_bit(unsigned char bit) -{ - spin_lock_irq(&rtc_lock); - set_rtc_irq_bit_locked(bit); - spin_unlock_irq(&rtc_lock); -} - -static void mask_rtc_irq_bit(unsigned char bit) -{ - spin_lock_irq(&rtc_lock); - mask_rtc_irq_bit_locked(bit); - spin_unlock_irq(&rtc_lock); -} -#endif - -#ifdef CONFIG_PROC_FS -static int rtc_proc_show(struct seq_file *seq, void *v); -#endif - -/* - * Bits in rtc_status. (6 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 */ - -/* - * rtc_status is never changed by rtc_interrupt, and ioctl/open/close is - * protected by the spin lock rtc_lock. However, ioctl can still disable the - * timer in rtc_status and then with del_timer after the interrupt has read - * rtc_status but before mod_timer is called, which would then reenable the - * timer (but you would need to have an awful timing before you'd trip on it) - */ -static unsigned long rtc_status; /* bitmapped status byte. */ -static unsigned long rtc_freq; /* Current periodic IRQ rate */ -static unsigned long rtc_irq_data; /* our output to the world */ -static unsigned long rtc_max_user_freq = 64; /* > this, need CAP_SYS_RESOURCE */ - -/* - * 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}; - -/* - * Returns true if a clock update is in progress - */ -static inline unsigned char rtc_is_updating(void) -{ - unsigned long flags; - unsigned char uip; - - spin_lock_irqsave(&rtc_lock, flags); - uip = (CMOS_READ(RTC_FREQ_SELECT) & RTC_UIP); - spin_unlock_irqrestore(&rtc_lock, flags); - return uip; -} - -#ifdef RTC_IRQ -/* - * A very tiny interrupt handler. It runs with interrupts disabled, - * but there is possibility of conflicting with the set_rtc_mmss() - * call (the rtc irq and the timer irq can easily run at the same - * time in two different CPUs). So we need to serialize - * accesses to the chip with the rtc_lock spinlock that each - * architecture should implement in the timer code. - * (See ./arch/XXXX/kernel/time.c for the set_rtc_mmss() function.) - */ - -static irqreturn_t rtc_interrupt(int irq, void *dev_id) -{ - /* - * Can be an alarm interrupt, update complete interrupt, - * or a periodic interrupt. We store the status in the - * low byte and the number of interrupts received since - * the last read in the remainder of rtc_irq_data. - */ - - spin_lock(&rtc_lock); - rtc_irq_data += 0x100; - rtc_irq_data &= ~0xff; - if (is_hpet_enabled()) { - /* - * In this case it is HPET RTC interrupt handler - * calling us, with the interrupt information - * passed as arg1, instead of irq. - */ - rtc_irq_data |= (unsigned long)irq & 0xF0; - } else { - rtc_irq_data |= (CMOS_READ(RTC_INTR_FLAGS) & 0xF0); - } - - if (rtc_status & RTC_TIMER_ON) - mod_timer(&rtc_irq_timer, jiffies + HZ/rtc_freq + 2*HZ/100); - - spin_unlock(&rtc_lock); - - wake_up_interruptible(&rtc_wait); - - kill_fasync(&rtc_async_queue, SIGIO, POLL_IN); - - return IRQ_HANDLED; -} -#endif - -/* - * sysctl-tuning infrastructure. - */ -static struct ctl_table rtc_table[] = { - { - .procname = "max-user-freq", - .data = &rtc_max_user_freq, - .maxlen = sizeof(int), - .mode = 0644, - .proc_handler = proc_dointvec, - }, - { } -}; - -static struct ctl_table rtc_root[] = { - { - .procname = "rtc", - .mode = 0555, - .child = rtc_table, - }, - { } -}; - -static struct ctl_table dev_root[] = { - { - .procname = "dev", - .mode = 0555, - .child = rtc_root, - }, - { } -}; - -static struct ctl_table_header *sysctl_header; - -static int __init init_sysctl(void) -{ - sysctl_header = register_sysctl_table(dev_root); - return 0; -} - -static void __exit cleanup_sysctl(void) -{ - unregister_sysctl_table(sysctl_header); -} - -/* - * 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) -{ -#ifndef RTC_IRQ - return -EIO; -#else - DECLARE_WAITQUEUE(wait, current); - unsigned long data; - ssize_t retval; - - if (rtc_has_irq == 0) - return -EIO; - - /* - * Historically this function used to assume that sizeof(unsigned long) - * is the same in userspace and kernelspace. This lead to problems - * for configurations with multiple ABIs such a the MIPS o32 and 64 - * ABIs supported on the same kernel. So now we support read of both - * 4 and 8 bytes and assume that's the sizeof(unsigned long) in the - * userspace ABI. - */ - if (count != sizeof(unsigned int) && count != sizeof(unsigned long)) - return -EINVAL; - - add_wait_queue(&rtc_wait, &wait); - - do { - /* First make it right. Then make it fast. Putting this whole - * block within the parentheses of a while would be too - * confusing. And no, xchg() is not the answer. */ - - __set_current_state(TASK_INTERRUPTIBLE); - - spin_lock_irq(&rtc_lock); - data = rtc_irq_data; - rtc_irq_data = 0; - spin_unlock_irq(&rtc_lock); - - if (data != 0) - break; - - if (file->f_flags & O_NONBLOCK) { - retval = -EAGAIN; - goto out; - } - if (signal_pending(current)) { - retval = -ERESTARTSYS; - goto out; - } - schedule(); - } while (1); - - if (count == sizeof(unsigned int)) { - retval = put_user(data, - (unsigned int __user *)buf) ?: sizeof(int); - } else { - retval = put_user(data, - (unsigned long __user *)buf) ?: sizeof(long); - } - if (!retval) - retval = count; - out: - __set_current_state(TASK_RUNNING); - remove_wait_queue(&rtc_wait, &wait); - - return retval; -#endif -} - -static int rtc_do_ioctl(unsigned int cmd, unsigned long arg, int kernel) -{ - struct rtc_time wtime; - -#ifdef RTC_IRQ - if (rtc_has_irq == 0) { - switch (cmd) { - case RTC_AIE_OFF: - case RTC_AIE_ON: - case RTC_PIE_OFF: - case RTC_PIE_ON: - case RTC_UIE_OFF: - case RTC_UIE_ON: - case RTC_IRQP_READ: - case RTC_IRQP_SET: - return -EINVAL; - } - } -#endif - - switch (cmd) { -#ifdef RTC_IRQ - case RTC_AIE_OFF: /* Mask alarm int. enab. bit */ - { - mask_rtc_irq_bit(RTC_AIE); - return 0; - } - case RTC_AIE_ON: /* Allow alarm interrupts. */ - { - set_rtc_irq_bit(RTC_AIE); - return 0; - } - case RTC_PIE_OFF: /* Mask periodic int. enab. bit */ - { - /* can be called from isr via rtc_control() */ - unsigned long flags; - - spin_lock_irqsave(&rtc_lock, flags); - mask_rtc_irq_bit_locked(RTC_PIE); - if (rtc_status & RTC_TIMER_ON) { - rtc_status &= ~RTC_TIMER_ON; - del_timer(&rtc_irq_timer); - } - spin_unlock_irqrestore(&rtc_lock, flags); - - return 0; - } - case RTC_PIE_ON: /* Allow periodic ints */ - { - /* can be called from isr via rtc_control() */ - unsigned long flags; - - /* - * We don't really want Joe User enabling more - * than 64Hz of interrupts on a multi-user machine. - */ - if (!kernel && (rtc_freq > rtc_max_user_freq) && - (!capable(CAP_SYS_RESOURCE))) - return -EACCES; - - spin_lock_irqsave(&rtc_lock, flags); - if (!(rtc_status & RTC_TIMER_ON)) { - mod_timer(&rtc_irq_timer, jiffies + HZ/rtc_freq + - 2*HZ/100); - rtc_status |= RTC_TIMER_ON; - } - set_rtc_irq_bit_locked(RTC_PIE); - spin_unlock_irqrestore(&rtc_lock, flags); - - return 0; - } - case RTC_UIE_OFF: /* Mask ints from RTC updates. */ - { - mask_rtc_irq_bit(RTC_UIE); - return 0; - } - case RTC_UIE_ON: /* Allow ints for RTC updates. */ - { - set_rtc_irq_bit(RTC_UIE); - return 0; - } -#endif - 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(struct rtc_time)); - get_rtc_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 (copy_from_user(&alm_tm, (struct rtc_time __user *)arg, - sizeof(struct rtc_time))) - return -EFAULT; - - hrs = alm_tm.tm_hour; - min = alm_tm.tm_min; - sec = alm_tm.tm_sec; - - spin_lock_irq(&rtc_lock); - if (hpet_set_alarm_time(hrs, min, sec)) { - /* - * Fallthru and set alarm time in CMOS too, - * so that we will get proper value in RTC_ALM_READ - */ - } - if (!(CMOS_READ(RTC_CONTROL) & RTC_DM_BINARY) || - RTC_ALWAYS_BCD) { - if (sec < 60) - sec = bin2bcd(sec); - else - sec = 0xff; - - if (min < 60) - min = bin2bcd(min); - else - min = 0xff; - - if (hrs < 24) - hrs = bin2bcd(hrs); - else - hrs = 0xff; - } - CMOS_WRITE(hrs, RTC_HOURS_ALARM); - CMOS_WRITE(min, RTC_MINUTES_ALARM); - CMOS_WRITE(sec, RTC_SECONDS_ALARM); - spin_unlock_irq(&rtc_lock); - - return 0; - } - case RTC_RD_TIME: /* Read the time/date from RTC */ - { - memset(&wtime, 0, sizeof(struct rtc_time)); - rtc_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 char save_control, save_freq_select; - unsigned int yrs; -#ifdef CONFIG_MACH_DECSTATION - unsigned int real_yrs; -#endif - - 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 + 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; - - yrs -= epoch; - if (yrs > 255) /* They are unsigned */ - return -EINVAL; - - spin_lock_irq(&rtc_lock); -#ifdef CONFIG_MACH_DECSTATION - real_yrs = yrs; - yrs = 72; - - /* - * We want to keep the year set to 73 until March - * for non-leap years, so that Feb, 29th is handled - * correctly. - */ - if (!leap_yr && mon < 3) { - real_yrs--; - yrs = 73; - } -#endif - /* These limits and adjustments are independent of - * whether the chip is in binary mode or not. - */ - if (yrs > 169) { - spin_unlock_irq(&rtc_lock); - return -EINVAL; - } - if (yrs >= 100) - yrs -= 100; - - if (!(CMOS_READ(RTC_CONTROL) & RTC_DM_BINARY) - || RTC_ALWAYS_BCD) { - sec = bin2bcd(sec); - min = bin2bcd(min); - hrs = bin2bcd(hrs); - day = bin2bcd(day); - mon = bin2bcd(mon); - yrs = bin2bcd(yrs); - } - - save_control = CMOS_READ(RTC_CONTROL); - CMOS_WRITE((save_control|RTC_SET), RTC_CONTROL); - save_freq_select = CMOS_READ(RTC_FREQ_SELECT); - CMOS_WRITE((save_freq_select|RTC_DIV_RESET2), RTC_FREQ_SELECT); - -#ifdef CONFIG_MACH_DECSTATION - CMOS_WRITE(real_yrs, RTC_DEC_YEAR); -#endif - CMOS_WRITE(yrs, RTC_YEAR); - CMOS_WRITE(mon, RTC_MONTH); - CMOS_WRITE(day, RTC_DAY_OF_MONTH); - CMOS_WRITE(hrs, RTC_HOURS); - CMOS_WRITE(min, RTC_MINUTES); - CMOS_WRITE(sec, RTC_SECONDS); - - CMOS_WRITE(save_control, RTC_CONTROL); - CMOS_WRITE(save_freq_select, RTC_FREQ_SELECT); - - spin_unlock_irq(&rtc_lock); - return 0; - } -#ifdef RTC_IRQ - case RTC_IRQP_READ: /* Read the periodic IRQ rate. */ - { - return put_user(rtc_freq, (unsigned long __user *)arg); - } - case RTC_IRQP_SET: /* Set periodic IRQ rate. */ - { - int tmp = 0; - unsigned char val; - /* can be called from isr via rtc_control() */ - unsigned long flags; - - /* - * The max we can do is 8192Hz. - */ - if ((arg < 2) || (arg > 8192)) - return -EINVAL; - /* - * We don't really want Joe User generating more - * than 64Hz of interrupts on a multi-user machine. - */ - if (!kernel && (arg > rtc_max_user_freq) && - !capable(CAP_SYS_RESOURCE)) - return -EACCES; - - while (arg > (1<<tmp)) - tmp++; - - /* - * Check that the input was really a power of 2. - */ - if (arg != (1<<tmp)) - return -EINVAL; - - rtc_freq = arg; - - spin_lock_irqsave(&rtc_lock, flags); - if (hpet_set_periodic_freq(arg)) { - spin_unlock_irqrestore(&rtc_lock, flags); - return 0; - } - - val = CMOS_READ(RTC_FREQ_SELECT) & 0xf0; - val |= (16 - tmp); - CMOS_WRITE(val, RTC_FREQ_SELECT); - spin_unlock_irqrestore(&rtc_lock, flags); - return 0; - } -#endif - 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 -ENOTTY; - } - return copy_to_user((void __user *)arg, - &wtime, sizeof wtime) ? -EFAULT : 0; -} - -static long rtc_ioctl(struct file *file, unsigned int cmd, unsigned long arg) -{ - long ret; - ret = rtc_do_ioctl(cmd, arg, 0); - return ret; -} - -/* - * 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 rtc_open(struct inode *inode, struct file *file) -{ - spin_lock_irq(&rtc_lock); - - if (rtc_status & RTC_IS_OPEN) - goto out_busy; - - rtc_status |= RTC_IS_OPEN; - - rtc_irq_data = 0; - spin_unlock_irq(&rtc_lock); - return 0; - -out_busy: - spin_unlock_irq(&rtc_lock); - return -EBUSY; -} - -static int rtc_fasync(int fd, struct file *filp, int on) -{ - return fasync_helper(fd, filp, on, &rtc_async_queue); -} - -static int rtc_release(struct inode *inode, struct file *file) -{ -#ifdef RTC_IRQ - unsigned char tmp; - - if (rtc_has_irq == 0) - goto no_irq; - - /* - * Turn off all interrupts once the device is no longer - * in use, and clear the data. - */ - - spin_lock_irq(&rtc_lock); - if (!hpet_mask_rtc_irq_bit(RTC_PIE | RTC_AIE | RTC_UIE)) { - tmp = CMOS_READ(RTC_CONTROL); - tmp &= ~RTC_PIE; - tmp &= ~RTC_AIE; - tmp &= ~RTC_UIE; - CMOS_WRITE(tmp, RTC_CONTROL); - CMOS_READ(RTC_INTR_FLAGS); - } - if (rtc_status & RTC_TIMER_ON) { - rtc_status &= ~RTC_TIMER_ON; - del_timer(&rtc_irq_timer); - } - spin_unlock_irq(&rtc_lock); - -no_irq: -#endif - - spin_lock_irq(&rtc_lock); - rtc_irq_data = 0; - rtc_status &= ~RTC_IS_OPEN; - spin_unlock_irq(&rtc_lock); - - return 0; -} - -#ifdef RTC_IRQ -static __poll_t rtc_poll(struct file *file, poll_table *wait) -{ - unsigned long l; - - if (rtc_has_irq == 0) - return 0; - - poll_wait(file, &rtc_wait, wait); - - spin_lock_irq(&rtc_lock); - l = rtc_irq_data; - spin_unlock_irq(&rtc_lock); - - if (l != 0) - return EPOLLIN | EPOLLRDNORM; - return 0; -} -#endif - -/* - * The various file operations we support. - */ - -static const struct file_operations rtc_fops = { - .owner = THIS_MODULE, - .llseek = no_llseek, - .read = rtc_read, -#ifdef RTC_IRQ - .poll = rtc_poll, -#endif - .unlocked_ioctl = rtc_ioctl, - .open = rtc_open, - .release = rtc_release, - .fasync = rtc_fasync, -}; - -static struct miscdevice rtc_dev = { - .minor = RTC_MINOR, - .name = "rtc", - .fops = &rtc_fops, -}; - -static resource_size_t rtc_size; - -static struct resource * __init rtc_request_region(resource_size_t size) -{ - struct resource *r; - - if (RTC_IOMAPPED) - r = request_region(RTC_PORT(0), size, "rtc"); - else - r = request_mem_region(RTC_PORT(0), size, "rtc"); - - if (r) - rtc_size = size; - - return r; -} - -static void rtc_release_region(void) -{ - if (RTC_IOMAPPED) - release_region(RTC_PORT(0), rtc_size); - else - release_mem_region(RTC_PORT(0), rtc_size); -} - -static int __init rtc_init(void) -{ -#ifdef CONFIG_PROC_FS - struct proc_dir_entry *ent; -#endif -#if defined(__alpha__) || defined(__mips__) - unsigned int year, ctrl; - char *guess = NULL; -#endif -#ifdef CONFIG_SPARC32 - struct device_node *ebus_dp; - struct platform_device *op; -#else - void *r; -#ifdef RTC_IRQ - irq_handler_t rtc_int_handler_ptr; -#endif -#endif - -#ifdef CONFIG_SPARC32 - for_each_node_by_name(ebus_dp, "ebus") { - struct device_node *dp; - for_each_child_of_node(ebus_dp, dp) { - if (of_node_name_eq(dp, "rtc")) { - op = of_find_device_by_node(dp); - if (op) { - rtc_port = op->resource[0].start; - rtc_irq = op->irqs[0]; - goto found; - } - } - } - } - rtc_has_irq = 0; - printk(KERN_ERR "rtc_init: no PC rtc found\n"); - return -EIO; - -found: - if (!rtc_irq) { - rtc_has_irq = 0; - goto no_irq; - } - - /* - * XXX Interrupt pin #7 in Espresso is shared between RTC and - * PCI Slot 2 INTA# (and some INTx# in Slot 1). - */ - if (request_irq(rtc_irq, rtc_interrupt, IRQF_SHARED, "rtc", - (void *)&rtc_port)) { - rtc_has_irq = 0; - printk(KERN_ERR "rtc: cannot register IRQ %d\n", rtc_irq); - return -EIO; - } -no_irq: -#else - r = rtc_request_region(RTC_IO_EXTENT); - - /* - * If we've already requested a smaller range (for example, because - * PNPBIOS or ACPI told us how the device is configured), the request - * above might fail because it's too big. - * - * If so, request just the range we actually use. - */ - if (!r) - r = rtc_request_region(RTC_IO_EXTENT_USED); - if (!r) { -#ifdef RTC_IRQ - rtc_has_irq = 0; -#endif - printk(KERN_ERR "rtc: I/O resource %lx is not free.\n", - (long)(RTC_PORT(0))); - return -EIO; - } - -#ifdef RTC_IRQ - if (is_hpet_enabled()) { - int err; - - rtc_int_handler_ptr = hpet_rtc_interrupt; - err = hpet_register_irq_handler(rtc_interrupt); - if (err != 0) { - printk(KERN_WARNING "hpet_register_irq_handler failed " - "in rtc_init()."); - return err; - } - } else { - rtc_int_handler_ptr = rtc_interrupt; - } - - if (request_irq(RTC_IRQ, rtc_int_handler_ptr, 0, "rtc", NULL)) { - /* Yeah right, seeing as irq 8 doesn't even hit the bus. */ - rtc_has_irq = 0; - printk(KERN_ERR "rtc: IRQ %d is not free.\n", RTC_IRQ); - rtc_release_region(); - - return -EIO; - } - hpet_rtc_timer_init(); - -#endif - -#endif /* CONFIG_SPARC32 vs. others */ - - if (misc_register(&rtc_dev)) { -#ifdef RTC_IRQ - free_irq(RTC_IRQ, NULL); - hpet_unregister_irq_handler(rtc_interrupt); - rtc_has_irq = 0; -#endif - rtc_release_region(); - return -ENODEV; - } - -#ifdef CONFIG_PROC_FS - ent = proc_create_single("driver/rtc", 0, NULL, rtc_proc_show); - if (!ent) - printk(KERN_WARNING "rtc: Failed to register with procfs.\n"); -#endif - -#if defined(__alpha__) || defined(__mips__) - rtc_freq = HZ; - - /* Each operating system on an Alpha uses its own epoch. - Let's try to guess which one we are using now. */ - - if (rtc_is_updating() != 0) - msleep(20); - - spin_lock_irq(&rtc_lock); - year = CMOS_READ(RTC_YEAR); - ctrl = CMOS_READ(RTC_CONTROL); - spin_unlock_irq(&rtc_lock); - - if (!(ctrl & RTC_DM_BINARY) || RTC_ALWAYS_BCD) - year = bcd2bin(year); /* This should never happen... */ - - if (year < 20) { - epoch = 2000; - guess = "SRM (post-2000)"; - } else if (year >= 20 && year < 48) { - epoch = 1980; - guess = "ARC console"; - } else if (year >= 48 && year < 72) { - epoch = 1952; - guess = "Digital UNIX"; -#if defined(__mips__) - } else if (year >= 72 && year < 74) { - epoch = 2000; - guess = "Digital DECstation"; -#else - } else if (year >= 70) { - epoch = 1900; - guess = "Standard PC (1900)"; -#endif - } - if (guess) - printk(KERN_INFO "rtc: %s epoch (%lu) detected\n", - guess, epoch); -#endif -#ifdef RTC_IRQ - if (rtc_has_irq == 0) - goto no_irq2; - - spin_lock_irq(&rtc_lock); - rtc_freq = 1024; - if (!hpet_set_periodic_freq(rtc_freq)) { - /* - * Initialize periodic frequency to CMOS reset default, - * which is 1024Hz - */ - CMOS_WRITE(((CMOS_READ(RTC_FREQ_SELECT) & 0xF0) | 0x06), - RTC_FREQ_SELECT); - } - spin_unlock_irq(&rtc_lock); -no_irq2: -#endif - - (void) init_sysctl(); - - printk(KERN_INFO "Real Time Clock Driver v" RTC_VERSION "\n"); - - return 0; -} - -static void __exit rtc_exit(void) -{ - cleanup_sysctl(); - remove_proc_entry("driver/rtc", NULL); - misc_deregister(&rtc_dev); - -#ifdef CONFIG_SPARC32 - if (rtc_has_irq) - free_irq(rtc_irq, &rtc_port); -#else - rtc_release_region(); -#ifdef RTC_IRQ - if (rtc_has_irq) { - free_irq(RTC_IRQ, NULL); - hpet_unregister_irq_handler(hpet_rtc_interrupt); - } -#endif -#endif /* CONFIG_SPARC32 */ -} - -module_init(rtc_init); -module_exit(rtc_exit); - -#ifdef RTC_IRQ -/* - * At IRQ rates >= 4096Hz, an interrupt may get lost altogether. - * (usually during an IDE disk interrupt, with IRQ unmasking off) - * Since the interrupt handler doesn't get called, the IRQ status - * byte doesn't get read, and the RTC stops generating interrupts. - * A timer is set, and will call this function if/when that happens. - * To get it out of this stalled state, we just read the status. - * At least a jiffy of interrupts (rtc_freq/HZ) will have been lost. - * (You *really* shouldn't be trying to use a non-realtime system - * for something that requires a steady > 1KHz signal anyways.) - */ - -static void rtc_dropped_irq(struct timer_list *unused) -{ - unsigned long freq; - - spin_lock_irq(&rtc_lock); - - if (hpet_rtc_dropped_irq()) { - spin_unlock_irq(&rtc_lock); - return; - } - - /* Just in case someone disabled the timer from behind our back... */ - if (rtc_status & RTC_TIMER_ON) - mod_timer(&rtc_irq_timer, jiffies + HZ/rtc_freq + 2*HZ/100); - - rtc_irq_data += ((rtc_freq/HZ)<<8); - rtc_irq_data &= ~0xff; - rtc_irq_data |= (CMOS_READ(RTC_INTR_FLAGS) & 0xF0); /* restart */ - - freq = rtc_freq; - - spin_unlock_irq(&rtc_lock); - - printk_ratelimited(KERN_WARNING "rtc: lost some interrupts at %ldHz.\n", - freq); - - /* Now we have new data */ - wake_up_interruptible(&rtc_wait); - - kill_fasync(&rtc_async_queue, SIGIO, POLL_IN); -} -#endif - -#ifdef CONFIG_PROC_FS -/* - * Info exported via "/proc/driver/rtc". - */ - -static int rtc_proc_show(struct seq_file *seq, void *v) -{ -#define YN(bit) ((ctrl & bit) ? "yes" : "no") -#define NY(bit) ((ctrl & bit) ? "no" : "yes") - struct rtc_time tm; - unsigned char batt, ctrl; - unsigned long freq; - - spin_lock_irq(&rtc_lock); - batt = CMOS_READ(RTC_VALID) & RTC_VRT; - ctrl = CMOS_READ(RTC_CONTROL); - freq = rtc_freq; - spin_unlock_irq(&rtc_lock); - - - rtc_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. - */ - seq_printf(seq, - "rtc_time\t: %ptRt\n" - "rtc_date\t: %ptRd\n" - "rtc_epoch\t: %04lu\n", - &tm, &tm, epoch); - - get_rtc_alm_time(&tm); - - /* - * 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. - */ - seq_puts(seq, "alarm\t\t: "); - if (tm.tm_hour <= 24) - seq_printf(seq, "%02d:", tm.tm_hour); - else - seq_puts(seq, "**:"); - - if (tm.tm_min <= 59) - seq_printf(seq, "%02d:", tm.tm_min); - else - seq_puts(seq, "**:"); - - if (tm.tm_sec <= 59) - seq_printf(seq, "%02d\n", tm.tm_sec); - else - seq_puts(seq, "**\n"); - - seq_printf(seq, - "DST_enable\t: %s\n" - "BCD\t\t: %s\n" - "24hr\t\t: %s\n" - "square_wave\t: %s\n" - "alarm_IRQ\t: %s\n" - "update_IRQ\t: %s\n" - "periodic_IRQ\t: %s\n" - "periodic_freq\t: %ld\n" - "batt_status\t: %s\n", - YN(RTC_DST_EN), - NY(RTC_DM_BINARY), - YN(RTC_24H), - YN(RTC_SQWE), - YN(RTC_AIE), - YN(RTC_UIE), - YN(RTC_PIE), - freq, - batt ? "okay" : "dead"); - - return 0; -#undef YN -#undef NY -} -#endif - -static void rtc_get_rtc_time(struct rtc_time *rtc_tm) -{ - unsigned long uip_watchdog = jiffies, flags; - unsigned char ctrl; -#ifdef CONFIG_MACH_DECSTATION - unsigned int real_year; -#endif - - /* - * read RTC once any update in progress is done. The update - * can take just over 2ms. We wait 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. - */ - - while (rtc_is_updating() != 0 && - time_before(jiffies, uip_watchdog + 2*HZ/100)) - cpu_relax(); - - /* - * Only the values that we read from the RTC are set. We leave - * tm_wday, tm_yday and tm_isdst untouched. Note that while the - * RTC has RTC_DAY_OF_WEEK, we should usually ignore it, as it is - * only updated by the RTC when initially set to a non-zero value. - */ - spin_lock_irqsave(&rtc_lock, flags); - rtc_tm->tm_sec = CMOS_READ(RTC_SECONDS); - rtc_tm->tm_min = CMOS_READ(RTC_MINUTES); - rtc_tm->tm_hour = CMOS_READ(RTC_HOURS); - rtc_tm->tm_mday = CMOS_READ(RTC_DAY_OF_MONTH); - rtc_tm->tm_mon = CMOS_READ(RTC_MONTH); - rtc_tm->tm_year = CMOS_READ(RTC_YEAR); - /* Only set from 2.6.16 onwards */ - rtc_tm->tm_wday = CMOS_READ(RTC_DAY_OF_WEEK); - -#ifdef CONFIG_MACH_DECSTATION - real_year = CMOS_READ(RTC_DEC_YEAR); -#endif - ctrl = CMOS_READ(RTC_CONTROL); - spin_unlock_irqrestore(&rtc_lock, flags); - - if (!(ctrl & RTC_DM_BINARY) || RTC_ALWAYS_BCD) { - 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); - rtc_tm->tm_wday = bcd2bin(rtc_tm->tm_wday); - } - -#ifdef CONFIG_MACH_DECSTATION - rtc_tm->tm_year += real_year - 72; -#endif - - /* - * Account for differences between how the RTC uses the values - * and how they are defined in a struct rtc_time; - */ - rtc_tm->tm_year += epoch - 1900; - if (rtc_tm->tm_year <= 69) - rtc_tm->tm_year += 100; - - rtc_tm->tm_mon--; -} - -static void get_rtc_alm_time(struct rtc_time *alm_tm) -{ - unsigned char ctrl; - - /* - * Only the values that we read from the RTC are set. That - * means only tm_hour, tm_min, and tm_sec. - */ - spin_lock_irq(&rtc_lock); - alm_tm->tm_sec = CMOS_READ(RTC_SECONDS_ALARM); - alm_tm->tm_min = CMOS_READ(RTC_MINUTES_ALARM); - alm_tm->tm_hour = CMOS_READ(RTC_HOURS_ALARM); - ctrl = CMOS_READ(RTC_CONTROL); - spin_unlock_irq(&rtc_lock); - - if (!(ctrl & RTC_DM_BINARY) || RTC_ALWAYS_BCD) { - alm_tm->tm_sec = bcd2bin(alm_tm->tm_sec); - alm_tm->tm_min = bcd2bin(alm_tm->tm_min); - alm_tm->tm_hour = bcd2bin(alm_tm->tm_hour); - } -} - -#ifdef RTC_IRQ -/* - * Used to disable/enable interrupts for any one of UIE, AIE, PIE. - * Rumour has it that if you frob the interrupt enable/disable - * bits in RTC_CONTROL, you should read RTC_INTR_FLAGS, to - * ensure you actually start getting interrupts. Probably for - * compatibility with older/broken chipset RTC implementations. - * We also clear out any old irq data after an ioctl() that - * meddles with the interrupt enable/disable bits. - */ - -static void mask_rtc_irq_bit_locked(unsigned char bit) -{ - unsigned char val; - - if (hpet_mask_rtc_irq_bit(bit)) - return; - val = CMOS_READ(RTC_CONTROL); - val &= ~bit; - CMOS_WRITE(val, RTC_CONTROL); - CMOS_READ(RTC_INTR_FLAGS); - - rtc_irq_data = 0; -} - -static void set_rtc_irq_bit_locked(unsigned char bit) -{ - unsigned char val; - - if (hpet_set_rtc_irq_bit(bit)) - return; - val = CMOS_READ(RTC_CONTROL); - val |= bit; - CMOS_WRITE(val, RTC_CONTROL); - CMOS_READ(RTC_INTR_FLAGS); - - rtc_irq_data = 0; -} -#endif - -MODULE_AUTHOR("Paul Gortmaker"); -MODULE_LICENSE("GPL"); -MODULE_ALIAS_MISCDEV(RTC_MINOR); |