diff options
Diffstat (limited to 'arch/m68k/bvme6000/rtc.c')
| -rw-r--r-- | arch/m68k/bvme6000/rtc.c | 175 |
1 files changed, 175 insertions, 0 deletions
diff --git a/arch/m68k/bvme6000/rtc.c b/arch/m68k/bvme6000/rtc.c new file mode 100644 index 000000000..b43eeef09 --- /dev/null +++ b/arch/m68k/bvme6000/rtc.c @@ -0,0 +1,175 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Real Time Clock interface for Linux on the BVME6000 + * + * Based on the PC driver by Paul Gortmaker. + */ + +#define RTC_VERSION "1.00" + +#include <linux/types.h> +#include <linux/errno.h> +#include <linux/miscdevice.h> +#include <linux/ioport.h> +#include <linux/capability.h> +#include <linux/fcntl.h> +#include <linux/init.h> +#include <linux/poll.h> +#include <linux/module.h> +#include <linux/rtc.h> /* For struct rtc_time and ioctls, etc */ +#include <linux/bcd.h> +#include <asm/bvme6000hw.h> + +#include <asm/io.h> +#include <linux/uaccess.h> +#include <asm/setup.h> + +/* + * 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 unsigned char days_in_mo[] = +{0, 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31}; + +static atomic_t rtc_status = ATOMIC_INIT(1); + +static long rtc_ioctl(struct file *file, unsigned int cmd, unsigned long arg) +{ + volatile RtcPtr_t rtc = (RtcPtr_t)BVME_RTC_BASE; + unsigned char msr; + unsigned long flags; + struct rtc_time wtime; + void __user *argp = (void __user *)arg; + + switch (cmd) { + case RTC_RD_TIME: /* Read the time/date from RTC */ + { + local_irq_save(flags); + /* Ensure clock and real-time-mode-register are accessible */ + msr = rtc->msr & 0xc0; + rtc->msr = 0x40; + memset(&wtime, 0, sizeof(struct rtc_time)); + do { + wtime.tm_sec = bcd2bin(rtc->bcd_sec); + wtime.tm_min = bcd2bin(rtc->bcd_min); + wtime.tm_hour = bcd2bin(rtc->bcd_hr); + wtime.tm_mday = bcd2bin(rtc->bcd_dom); + wtime.tm_mon = bcd2bin(rtc->bcd_mth)-1; + wtime.tm_year = bcd2bin(rtc->bcd_year); + if (wtime.tm_year < 70) + wtime.tm_year += 100; + wtime.tm_wday = bcd2bin(rtc->bcd_dow)-1; + } while (wtime.tm_sec != bcd2bin(rtc->bcd_sec)); + rtc->msr = msr; + local_irq_restore(flags); + return copy_to_user(argp, &wtime, sizeof wtime) ? + -EFAULT : 0; + } + case RTC_SET_TIME: /* Set the RTC */ + { + struct rtc_time rtc_tm; + unsigned char mon, day, hrs, min, sec, leap_yr; + unsigned int yrs; + + if (!capable(CAP_SYS_ADMIN)) + return -EACCES; + + if (copy_from_user(&rtc_tm, argp, sizeof(struct rtc_time))) + return -EFAULT; + + yrs = rtc_tm.tm_year; + if (yrs < 1900) + yrs += 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; + + leap_yr = ((!(yrs % 4) && (yrs % 100)) || !(yrs % 400)); + + if ((mon > 12) || (mon < 1) || (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 >= 2070) + return -EINVAL; + + local_irq_save(flags); + /* Ensure clock and real-time-mode-register are accessible */ + msr = rtc->msr & 0xc0; + rtc->msr = 0x40; + + rtc->t0cr_rtmr = yrs%4; + rtc->bcd_tenms = 0; + rtc->bcd_sec = bin2bcd(sec); + rtc->bcd_min = bin2bcd(min); + rtc->bcd_hr = bin2bcd(hrs); + rtc->bcd_dom = bin2bcd(day); + rtc->bcd_mth = bin2bcd(mon); + rtc->bcd_year = bin2bcd(yrs%100); + if (rtc_tm.tm_wday >= 0) + rtc->bcd_dow = bin2bcd(rtc_tm.tm_wday+1); + rtc->t0cr_rtmr = yrs%4 | 0x08; + + rtc->msr = msr; + local_irq_restore(flags); + return 0; + } + default: + return -EINVAL; + } +} + +/* + * We enforce only one user at a time here with the open/close. + */ +static int rtc_open(struct inode *inode, struct file *file) +{ + if (!atomic_dec_and_test(&rtc_status)) { + atomic_inc(&rtc_status); + return -EBUSY; + } + return 0; +} + +static int rtc_release(struct inode *inode, struct file *file) +{ + atomic_inc(&rtc_status); + return 0; +} + +/* + * The various file operations we support. + */ + +static const struct file_operations rtc_fops = { + .unlocked_ioctl = rtc_ioctl, + .open = rtc_open, + .release = rtc_release, + .llseek = noop_llseek, +}; + +static struct miscdevice rtc_dev = { + .minor = RTC_MINOR, + .name = "rtc", + .fops = &rtc_fops +}; + +static int __init rtc_DP8570A_init(void) +{ + if (!MACH_IS_BVME6000) + return -ENODEV; + + pr_info("DP8570A Real Time Clock Driver v%s\n", RTC_VERSION); + return misc_register(&rtc_dev); +} +module_init(rtc_DP8570A_init); |