diff options
Diffstat (limited to 'drivers/sbus/char/rtc.c')
| -rw-r--r-- | drivers/sbus/char/rtc.c | 178 |
1 files changed, 178 insertions, 0 deletions
diff --git a/drivers/sbus/char/rtc.c b/drivers/sbus/char/rtc.c new file mode 100644 index 000000000000..bf3273eb1c8b --- /dev/null +++ b/drivers/sbus/char/rtc.c @@ -0,0 +1,178 @@ +/* $Id: rtc.c,v 1.28 2001/10/08 22:19:51 davem Exp $ + * + * Linux/SPARC Real Time Clock Driver + * Copyright (C) 1996 Thomas K. Dyas (tdyas@eden.rutgers.edu) + * + * This is a little driver that lets a user-level program access + * the SPARC Mostek real time clock chip. It is no use unless you + * use the modified clock utility. + * + * Get the modified clock utility from: + * ftp://vger.kernel.org/pub/linux/Sparc/userland/clock.c + */ + +#include <linux/module.h> +#include <linux/types.h> +#include <linux/errno.h> +#include <linux/miscdevice.h> +#include <linux/slab.h> +#include <linux/fcntl.h> +#include <linux/poll.h> +#include <linux/init.h> +#include <linux/smp_lock.h> +#include <asm/io.h> +#include <asm/mostek.h> +#include <asm/system.h> +#include <asm/uaccess.h> +#include <asm/rtc.h> + +static int rtc_busy = 0; + +/* Retrieve the current date and time from the real time clock. */ +static void get_rtc_time(struct rtc_time *t) +{ + void * __iomem regs = mstk48t02_regs; + u8 tmp; + + spin_lock_irq(&mostek_lock); + + tmp = mostek_read(regs + MOSTEK_CREG); + tmp |= MSTK_CREG_READ; + mostek_write(regs + MOSTEK_CREG, tmp); + + t->sec = MSTK_REG_SEC(regs); + t->min = MSTK_REG_MIN(regs); + t->hour = MSTK_REG_HOUR(regs); + t->dow = MSTK_REG_DOW(regs); + t->dom = MSTK_REG_DOM(regs); + t->month = MSTK_REG_MONTH(regs); + t->year = MSTK_CVT_YEAR( MSTK_REG_YEAR(regs) ); + + tmp = mostek_read(regs + MOSTEK_CREG); + tmp &= ~MSTK_CREG_READ; + mostek_write(regs + MOSTEK_CREG, tmp); + + spin_unlock_irq(&mostek_lock); +} + +/* Set the current date and time inthe real time clock. */ +void set_rtc_time(struct rtc_time *t) +{ + void * __iomem regs = mstk48t02_regs; + u8 tmp; + + spin_lock_irq(&mostek_lock); + + tmp = mostek_read(regs + MOSTEK_CREG); + tmp |= MSTK_CREG_WRITE; + mostek_write(regs + MOSTEK_CREG, tmp); + + MSTK_SET_REG_SEC(regs,t->sec); + MSTK_SET_REG_MIN(regs,t->min); + MSTK_SET_REG_HOUR(regs,t->hour); + MSTK_SET_REG_DOW(regs,t->dow); + MSTK_SET_REG_DOM(regs,t->dom); + MSTK_SET_REG_MONTH(regs,t->month); + MSTK_SET_REG_YEAR(regs,t->year - MSTK_YEAR_ZERO); + + tmp = mostek_read(regs + MOSTEK_CREG); + tmp &= ~MSTK_CREG_WRITE; + mostek_write(regs + MOSTEK_CREG, tmp); + + spin_unlock_irq(&mostek_lock); +} + +static int rtc_ioctl(struct inode *inode, struct file *file, unsigned int cmd, + unsigned long arg) +{ + struct rtc_time rtc_tm; + void __user *argp = (void __user *)arg; + + switch (cmd) + { + case RTCGET: + memset(&rtc_tm, 0, sizeof(struct rtc_time)); + get_rtc_time(&rtc_tm); + + if (copy_to_user(argp, &rtc_tm, sizeof(struct rtc_time))) + return -EFAULT; + + return 0; + + + case RTCSET: + if (!capable(CAP_SYS_TIME)) + return -EPERM; + + if (copy_from_user(&rtc_tm, argp, sizeof(struct rtc_time))) + return -EFAULT; + + set_rtc_time(&rtc_tm); + + return 0; + + default: + return -EINVAL; + } +} + +static int rtc_open(struct inode *inode, struct file *file) +{ + int ret; + + spin_lock_irq(&mostek_lock); + if (rtc_busy) { + ret = -EBUSY; + } else { + rtc_busy = 1; + ret = 0; + } + spin_unlock_irq(&mostek_lock); + + return ret; +} + +static int rtc_release(struct inode *inode, struct file *file) +{ + rtc_busy = 0; + + return 0; +} + +static struct file_operations rtc_fops = { + .owner = THIS_MODULE, + .llseek = no_llseek, + .ioctl = rtc_ioctl, + .open = rtc_open, + .release = rtc_release, +}; + +static struct miscdevice rtc_dev = { RTC_MINOR, "rtc", &rtc_fops }; + +static int __init rtc_sun_init(void) +{ + int error; + + /* It is possible we are being driven by some other RTC chip + * and thus another RTC driver is handling things. + */ + if (mstk48t02_regs == 0) + return -ENODEV; + + error = misc_register(&rtc_dev); + if (error) { + printk(KERN_ERR "rtc: unable to get misc minor for Mostek\n"); + return error; + } + + return 0; +} + +static void __exit rtc_sun_cleanup(void) +{ + misc_deregister(&rtc_dev); +} + +module_init(rtc_sun_init); +module_exit(rtc_sun_cleanup); +MODULE_LICENSE("GPL"); |