/* * 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. * * 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. * * 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_IRQstatic 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_IRQstatic 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_IRQstatic void rtc_dropped_irq(unsigned long data); static DEFINE_TIMER(rtc_irq_timer, rtc_dropped_irq, 0, 0);#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_IRQstatic unsigned int rtc_poll(struct file *file, poll_table *wait);#endif static void get_rtc_alm_time(struct rtc_time *alm_tm);#ifdef RTC_IRQstatic 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_FSstatic int rtc_proc_open(struct inode *inode, struct file *file);#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 */ #ifdef RTC_IRQ/* * rtc_task_lock nests inside rtc_lock. */static DEFINE_SPINLOCK(rtc_task_lock);static rtc_task_t *rtc_callback;#endif /* * 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); /* Now do the rest of the actions */ spin_lock(&rtc_task_lock); if (rtc_callback) rtc_callback->func(rtc_callback->private_data); spin_unlock(&rtc_task_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; Lines 1–500 of 1427. Load more
/* * 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. * * 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. * * 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(unsigned long data); static DEFINE_TIMER(rtc_irq_timer, rtc_dropped_irq, 0, 0); #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 unsigned int 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_open(struct inode *inode, struct file *file); #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 */ #ifdef RTC_IRQ /* * rtc_task_lock nests inside rtc_lock. */ static DEFINE_SPINLOCK(rtc_task_lock); static rtc_task_t *rtc_callback; #endif /* * 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); /* Now do the rest of the actions */ spin_lock(&rtc_task_lock); if (rtc_callback) rtc_callback->func(rtc_callback->private_data); spin_unlock(&rtc_task_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;