diff options
Diffstat (limited to 'drivers/char/rtc.c')
| -rw-r--r-- | drivers/char/rtc.c | 238 |
1 files changed, 129 insertions, 109 deletions
diff --git a/drivers/char/rtc.c b/drivers/char/rtc.c index 0c66b802736..3ac7952fe08 100644 --- a/drivers/char/rtc.c +++ b/drivers/char/rtc.c @@ -1,5 +1,5 @@ /* - * Real Time Clock interface for Linux + * Real Time Clock interface for Linux * * Copyright (C) 1996 Paul Gortmaker * @@ -17,7 +17,7 @@ * 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 + * 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 @@ -104,12 +104,12 @@ static int rtc_has_irq = 1; #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_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 #ifdef RTC_IRQ static irqreturn_t hpet_rtc_interrupt(int irq, void *dev_id) { @@ -147,7 +147,7 @@ static int rtc_ioctl(struct inode *inode, struct file *file, static unsigned int rtc_poll(struct file *file, poll_table *wait); #endif -static void get_rtc_alm_time (struct rtc_time *alm_tm); +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); @@ -185,9 +185,9 @@ static int rtc_proc_open(struct inode *inode, struct file *file); * 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 = 0; /* bitmapped status byte. */ -static unsigned long rtc_freq = 0; /* Current periodic IRQ rate */ -static unsigned long rtc_irq_data = 0; /* our output to the world */ +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 @@ -195,7 +195,7 @@ static unsigned long rtc_max_user_freq = 64; /* > this, need CAP_SYS_RESOURCE */ * rtc_task_lock nests inside rtc_lock. */ static DEFINE_SPINLOCK(rtc_task_lock); -static rtc_task_t *rtc_callback = NULL; +static rtc_task_t *rtc_callback; #endif /* @@ -205,7 +205,7 @@ static rtc_task_t *rtc_callback = NULL; static unsigned long epoch = 1900; /* year corresponding to 0x00 */ -static const unsigned char days_in_mo[] = +static const unsigned char days_in_mo[] = {0, 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31}; /* @@ -242,7 +242,7 @@ irqreturn_t rtc_interrupt(int irq, void *dev_id) * the last read in the remainder of rtc_irq_data. */ - spin_lock (&rtc_lock); + spin_lock(&rtc_lock); rtc_irq_data += 0x100; rtc_irq_data &= ~0xff; if (is_hpet_enabled()) { @@ -259,16 +259,16 @@ irqreturn_t rtc_interrupt(int irq, void *dev_id) if (rtc_status & RTC_TIMER_ON) mod_timer(&rtc_irq_timer, jiffies + HZ/rtc_freq + 2*HZ/100); - spin_unlock (&rtc_lock); + 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); + wake_up_interruptible(&rtc_wait); - kill_fasync (&rtc_async_queue, SIGIO, POLL_IN); + kill_fasync(&rtc_async_queue, SIGIO, POLL_IN); return IRQ_HANDLED; } @@ -335,7 +335,7 @@ static ssize_t rtc_read(struct file *file, char __user *buf, DECLARE_WAITQUEUE(wait, current); unsigned long data; ssize_t retval; - + if (rtc_has_irq == 0) return -EIO; @@ -358,11 +358,11 @@ static ssize_t rtc_read(struct file *file, char __user *buf, * confusing. And no, xchg() is not the answer. */ __set_current_state(TASK_INTERRUPTIBLE); - - spin_lock_irq (&rtc_lock); + + spin_lock_irq(&rtc_lock); data = rtc_irq_data; rtc_irq_data = 0; - spin_unlock_irq (&rtc_lock); + spin_unlock_irq(&rtc_lock); if (data != 0) break; @@ -378,10 +378,13 @@ static ssize_t rtc_read(struct file *file, char __user *buf, 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 (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: @@ -394,7 +397,7 @@ static ssize_t rtc_read(struct file *file, char __user *buf, static int rtc_do_ioctl(unsigned int cmd, unsigned long arg, int kernel) { - struct rtc_time wtime; + struct rtc_time wtime; #ifdef RTC_IRQ if (rtc_has_irq == 0) { @@ -426,35 +429,41 @@ static int rtc_do_ioctl(unsigned int cmd, unsigned long arg, int kernel) } case RTC_PIE_OFF: /* Mask periodic int. enab. bit */ { - unsigned long flags; /* can be called from isr via rtc_control() */ - spin_lock_irqsave (&rtc_lock, flags); + /* 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); + spin_unlock_irqrestore(&rtc_lock, flags); + return 0; } case RTC_PIE_ON: /* Allow periodic ints */ { - unsigned long flags; /* can be called from isr via rtc_control() */ + /* 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))) + (!capable(CAP_SYS_RESOURCE))) return -EACCES; - spin_lock_irqsave (&rtc_lock, flags); + 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); + spin_unlock_irqrestore(&rtc_lock, flags); + return 0; } case RTC_UIE_OFF: /* Mask ints from RTC updates. */ @@ -477,7 +486,7 @@ static int rtc_do_ioctl(unsigned int cmd, unsigned long arg, int kernel) */ memset(&wtime, 0, sizeof(struct rtc_time)); get_rtc_alm_time(&wtime); - break; + break; } case RTC_ALM_SET: /* Store a time into the alarm */ { @@ -505,16 +514,21 @@ static int rtc_do_ioctl(unsigned int cmd, unsigned long arg, int kernel) */ } if (!(CMOS_READ(RTC_CONTROL) & RTC_DM_BINARY) || - RTC_ALWAYS_BCD) - { - if (sec < 60) BIN_TO_BCD(sec); - else sec = 0xff; - - if (min < 60) BIN_TO_BCD(min); - else min = 0xff; - - if (hrs < 24) BIN_TO_BCD(hrs); - else hrs = 0xff; + RTC_ALWAYS_BCD) { + if (sec < 60) + BIN_TO_BCD(sec); + else + sec = 0xff; + + if (min < 60) + BIN_TO_BCD(min); + else + min = 0xff; + + if (hrs < 24) + BIN_TO_BCD(hrs); + else + hrs = 0xff; } CMOS_WRITE(hrs, RTC_HOURS_ALARM); CMOS_WRITE(min, RTC_MINUTES_ALARM); @@ -563,11 +577,12 @@ static int rtc_do_ioctl(unsigned int cmd, unsigned long arg, int kernel) if (day > (days_in_mo[mon] + ((mon == 2) && leap_yr))) return -EINVAL; - + if ((hrs >= 24) || (min >= 60) || (sec >= 60)) return -EINVAL; - if ((yrs -= epoch) > 255) /* They are unsigned */ + yrs -= epoch; + if (yrs > 255) /* They are unsigned */ return -EINVAL; spin_lock_irq(&rtc_lock); @@ -635,9 +650,10 @@ static int rtc_do_ioctl(unsigned int cmd, unsigned long arg, int kernel) { int tmp = 0; unsigned char val; - unsigned long flags; /* can be called from isr via rtc_control() */ + /* can be called from isr via rtc_control() */ + unsigned long flags; - /* + /* * The max we can do is 8192Hz. */ if ((arg < 2) || (arg > 8192)) @@ -646,7 +662,8 @@ static int rtc_do_ioctl(unsigned int cmd, unsigned long arg, int kernel) * 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))) + if (!kernel && (arg > rtc_max_user_freq) && + !capable(CAP_SYS_RESOURCE)) return -EACCES; while (arg > (1<<tmp)) @@ -674,11 +691,11 @@ static int rtc_do_ioctl(unsigned int cmd, unsigned long arg, int kernel) #endif case RTC_EPOCH_READ: /* Read the epoch. */ { - return put_user (epoch, (unsigned long __user *)arg); + 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) @@ -693,7 +710,8 @@ static int rtc_do_ioctl(unsigned int cmd, unsigned long arg, int kernel) default: return -ENOTTY; } - return copy_to_user((void __user *)arg, &wtime, sizeof wtime) ? -EFAULT : 0; + return copy_to_user((void __user *)arg, + &wtime, sizeof wtime) ? -EFAULT : 0; } static int rtc_ioctl(struct inode *inode, struct file *file, unsigned int cmd, @@ -712,26 +730,25 @@ static int rtc_ioctl(struct inode *inode, struct file *file, unsigned int cmd, * needed here. Or anywhere else in this driver. */ static int rtc_open(struct inode *inode, struct file *file) { - spin_lock_irq (&rtc_lock); + spin_lock_irq(&rtc_lock); - if(rtc_status & RTC_IS_OPEN) + if (rtc_status & RTC_IS_OPEN) goto out_busy; rtc_status |= RTC_IS_OPEN; rtc_irq_data = 0; - spin_unlock_irq (&rtc_lock); + spin_unlock_irq(&rtc_lock); return 0; out_busy: - spin_unlock_irq (&rtc_lock); + spin_unlock_irq(&rtc_lock); return -EBUSY; } -static int rtc_fasync (int fd, struct file *filp, int on) - +static int rtc_fasync(int fd, struct file *filp, int on) { - return fasync_helper (fd, filp, on, &rtc_async_queue); + return fasync_helper(fd, filp, on, &rtc_async_queue); } static int rtc_release(struct inode *inode, struct file *file) @@ -762,16 +779,16 @@ static int rtc_release(struct inode *inode, struct file *file) } spin_unlock_irq(&rtc_lock); - if (file->f_flags & FASYNC) { - rtc_fasync (-1, file, 0); - } + if (file->f_flags & FASYNC) + rtc_fasync(-1, file, 0); no_irq: #endif - spin_lock_irq (&rtc_lock); + spin_lock_irq(&rtc_lock); rtc_irq_data = 0; rtc_status &= ~RTC_IS_OPEN; - spin_unlock_irq (&rtc_lock); + spin_unlock_irq(&rtc_lock); + return 0; } @@ -786,9 +803,9 @@ static unsigned int rtc_poll(struct file *file, poll_table *wait) poll_wait(file, &rtc_wait, wait); - spin_lock_irq (&rtc_lock); + spin_lock_irq(&rtc_lock); l = rtc_irq_data; - spin_unlock_irq (&rtc_lock); + spin_unlock_irq(&rtc_lock); if (l != 0) return POLLIN | POLLRDNORM; @@ -796,14 +813,6 @@ static unsigned int rtc_poll(struct file *file, poll_table *wait) } #endif -/* - * exported stuffs - */ - -EXPORT_SYMBOL(rtc_register); -EXPORT_SYMBOL(rtc_unregister); -EXPORT_SYMBOL(rtc_control); - int rtc_register(rtc_task_t *task) { #ifndef RTC_IRQ @@ -829,6 +838,7 @@ int rtc_register(rtc_task_t *task) return 0; #endif } +EXPORT_SYMBOL(rtc_register); int rtc_unregister(rtc_task_t *task) { @@ -845,7 +855,7 @@ int rtc_unregister(rtc_task_t *task) return -ENXIO; } rtc_callback = NULL; - + /* disable controls */ if (!hpet_mask_rtc_irq_bit(RTC_PIE | RTC_AIE | RTC_UIE)) { tmp = CMOS_READ(RTC_CONTROL); @@ -865,6 +875,7 @@ int rtc_unregister(rtc_task_t *task) return 0; #endif } +EXPORT_SYMBOL(rtc_unregister); int rtc_control(rtc_task_t *task, unsigned int cmd, unsigned long arg) { @@ -883,7 +894,7 @@ int rtc_control(rtc_task_t *task, unsigned int cmd, unsigned long arg) return rtc_do_ioctl(cmd, arg, 1); #endif } - +EXPORT_SYMBOL(rtc_control); /* * The various file operations we support. @@ -910,11 +921,11 @@ static struct miscdevice rtc_dev = { #ifdef CONFIG_PROC_FS static const struct file_operations rtc_proc_fops = { - .owner = THIS_MODULE, - .open = rtc_proc_open, - .read = seq_read, - .llseek = seq_lseek, - .release = single_release, + .owner = THIS_MODULE, + .open = rtc_proc_open, + .read = seq_read, + .llseek = seq_lseek, + .release = single_release, }; #endif @@ -965,7 +976,7 @@ static int __init rtc_init(void) #ifdef CONFIG_SPARC32 for_each_ebus(ebus) { for_each_ebusdev(edev, ebus) { - if(strcmp(edev->prom_node->name, "rtc") == 0) { + if (strcmp(edev->prom_node->name, "rtc") == 0) { rtc_port = edev->resource[0].start; rtc_irq = edev->irqs[0]; goto found; @@ -986,7 +997,8 @@ found: * 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)) { + 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; @@ -1020,11 +1032,13 @@ no_irq: rtc_int_handler_ptr = rtc_interrupt; } - if(request_irq(RTC_IRQ, rtc_int_handler_ptr, IRQF_DISABLED, "rtc", NULL)) { + if (request_irq(RTC_IRQ, rtc_int_handler_ptr, IRQF_DISABLED, + "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(); @@ -1052,21 +1066,21 @@ no_irq: #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) BCD_TO_BIN(year); /* This should never happen... */ - + if (year < 20) { epoch = 2000; guess = "SRM (post-2000)"; @@ -1087,7 +1101,8 @@ no_irq: #endif } if (guess) - printk(KERN_INFO "rtc: %s epoch (%lu) detected\n", guess, epoch); + printk(KERN_INFO "rtc: %s epoch (%lu) detected\n", + guess, epoch); #endif #ifdef RTC_IRQ if (rtc_has_irq == 0) @@ -1096,8 +1111,12 @@ no_irq: spin_lock_irq(&rtc_lock); rtc_freq = 1024; if (!hpet_set_periodic_freq(rtc_freq)) { - /* Initialize periodic freq. to CMOS reset default, which is 1024Hz */ - CMOS_WRITE(((CMOS_READ(RTC_FREQ_SELECT) & 0xF0) | 0x06), RTC_FREQ_SELECT); + /* + * 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: @@ -1110,20 +1129,20 @@ no_irq2: return 0; } -static void __exit rtc_exit (void) +static void __exit rtc_exit(void) { cleanup_sysctl(); - remove_proc_entry ("driver/rtc", NULL); + remove_proc_entry("driver/rtc", NULL); misc_deregister(&rtc_dev); #ifdef CONFIG_SPARC32 if (rtc_has_irq) - free_irq (rtc_irq, &rtc_port); + free_irq(rtc_irq, &rtc_port); #else rtc_release_region(); #ifdef RTC_IRQ if (rtc_has_irq) - free_irq (RTC_IRQ, NULL); + free_irq(RTC_IRQ, NULL); #endif #endif /* CONFIG_SPARC32 */ } @@ -1133,14 +1152,14 @@ module_exit(rtc_exit); #ifdef RTC_IRQ /* - * At IRQ rates >= 4096Hz, an interrupt may get lost altogether. + * 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 + * (You *really* shouldn't be trying to use a non-realtime system * for something that requires a steady > 1KHz signal anyways.) */ @@ -1148,7 +1167,7 @@ static void rtc_dropped_irq(unsigned long data) { unsigned long freq; - spin_lock_irq (&rtc_lock); + spin_lock_irq(&rtc_lock); if (hpet_rtc_dropped_irq()) { spin_unlock_irq(&rtc_lock); @@ -1167,13 +1186,15 @@ static void rtc_dropped_irq(unsigned long data) spin_unlock_irq(&rtc_lock); - if (printk_ratelimit()) - printk(KERN_WARNING "rtc: lost some interrupts at %ldHz.\n", freq); + if (printk_ratelimit()) { + printk(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); + kill_fasync(&rtc_async_queue, SIGIO, POLL_IN); } #endif @@ -1277,7 +1298,7 @@ void rtc_get_rtc_time(struct rtc_time *rtc_tm) * 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 + * 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. */ @@ -1307,8 +1328,7 @@ void rtc_get_rtc_time(struct rtc_time *rtc_tm) ctrl = CMOS_READ(RTC_CONTROL); spin_unlock_irqrestore(&rtc_lock, flags); - if (!(ctrl & RTC_DM_BINARY) || RTC_ALWAYS_BCD) - { + if (!(ctrl & RTC_DM_BINARY) || RTC_ALWAYS_BCD) { BCD_TO_BIN(rtc_tm->tm_sec); BCD_TO_BIN(rtc_tm->tm_min); BCD_TO_BIN(rtc_tm->tm_hour); @@ -1326,7 +1346,8 @@ void rtc_get_rtc_time(struct rtc_time *rtc_tm) * 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 += (epoch - 1900)) <= 69) + rtc_tm->tm_year += epoch - 1900; + if (rtc_tm->tm_year <= 69) rtc_tm->tm_year += 100; rtc_tm->tm_mon--; @@ -1347,8 +1368,7 @@ static void get_rtc_alm_time(struct rtc_time *alm_tm) ctrl = CMOS_READ(RTC_CONTROL); spin_unlock_irq(&rtc_lock); - if (!(ctrl & RTC_DM_BINARY) || RTC_ALWAYS_BCD) - { + if (!(ctrl & RTC_DM_BINARY) || RTC_ALWAYS_BCD) { BCD_TO_BIN(alm_tm->tm_sec); BCD_TO_BIN(alm_tm->tm_min); BCD_TO_BIN(alm_tm->tm_hour); |