diff options
Diffstat (limited to 'drivers/char/s3c2410-rtc.c')
| -rw-r--r-- | drivers/char/s3c2410-rtc.c | 588 |
1 files changed, 588 insertions, 0 deletions
diff --git a/drivers/char/s3c2410-rtc.c b/drivers/char/s3c2410-rtc.c new file mode 100644 index 000000000000..ec666395a26c --- /dev/null +++ b/drivers/char/s3c2410-rtc.c @@ -0,0 +1,588 @@ +/* drivers/char/s3c2410_rtc.c + * + * Copyright (c) 2004 Simtec Electronics <linux@simtec.co.uk> + * http://www.simtec.co.uk/products/SWLINUX/ + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + * + * S3C2410 Internal RTC Driver + * + * Changelog: + * 08-Nov-2004 BJD Initial creation + * 12-Nov-2004 BJD Added periodic IRQ and PM code + * 22-Nov-2004 BJD Sign-test on alarm code to check for <0 + * 10-Mar-2005 LCVR Changed S3C2410_VA_RTC to S3C24XX_VA_RTC +*/ + +#include <linux/module.h> +#include <linux/fs.h> +#include <linux/string.h> +#include <linux/init.h> +#include <linux/device.h> +#include <linux/interrupt.h> +#include <linux/rtc.h> +#include <linux/bcd.h> + +#include <asm/hardware.h> +#include <asm/uaccess.h> +#include <asm/io.h> +#include <asm/irq.h> +#include <asm/rtc.h> + +#include <asm/mach/time.h> + +#include <asm/hardware/clock.h> +#include <asm/arch/regs-rtc.h> + +/* need this for the RTC_AF definitions */ +#include <linux/mc146818rtc.h> + +#undef S3C24XX_VA_RTC +#define S3C24XX_VA_RTC s3c2410_rtc_base + +static struct resource *s3c2410_rtc_mem; + +static void __iomem *s3c2410_rtc_base; +static int s3c2410_rtc_alarmno = NO_IRQ; +static int s3c2410_rtc_tickno = NO_IRQ; +static int s3c2410_rtc_freq = 1; + +static DEFINE_SPINLOCK(s3c2410_rtc_pie_lock); + +/* IRQ Handlers */ + +static irqreturn_t s3c2410_rtc_alarmirq(int irq, void *id, struct pt_regs *r) +{ + rtc_update(1, RTC_AF | RTC_IRQF); + return IRQ_HANDLED; +} + +static irqreturn_t s3c2410_rtc_tickirq(int irq, void *id, struct pt_regs *r) +{ + rtc_update(1, RTC_PF | RTC_IRQF); + return IRQ_HANDLED; +} + +/* Update control registers */ +static void s3c2410_rtc_setaie(int to) +{ + unsigned int tmp; + + pr_debug("%s: aie=%d\n", __FUNCTION__, to); + + tmp = readb(S3C2410_RTCALM); + + if (to) + tmp |= S3C2410_RTCALM_ALMEN; + else + tmp &= ~S3C2410_RTCALM_ALMEN; + + + writeb(tmp, S3C2410_RTCALM); +} + +static void s3c2410_rtc_setpie(int to) +{ + unsigned int tmp; + + pr_debug("%s: pie=%d\n", __FUNCTION__, to); + + spin_lock_irq(&s3c2410_rtc_pie_lock); + tmp = readb(S3C2410_TICNT) & ~S3C2410_TICNT_ENABLE; + + if (to) + tmp |= S3C2410_TICNT_ENABLE; + + writeb(tmp, S3C2410_TICNT); + spin_unlock_irq(&s3c2410_rtc_pie_lock); +} + +static void s3c2410_rtc_setfreq(int freq) +{ + unsigned int tmp; + + spin_lock_irq(&s3c2410_rtc_pie_lock); + tmp = readb(S3C2410_TICNT) & S3C2410_TICNT_ENABLE; + + s3c2410_rtc_freq = freq; + + tmp |= (128 / freq)-1; + + writeb(tmp, S3C2410_TICNT); + spin_unlock_irq(&s3c2410_rtc_pie_lock); +} + +/* Time read/write */ + +static void s3c2410_rtc_gettime(struct rtc_time *rtc_tm) +{ + unsigned int have_retried = 0; + + retry_get_time: + rtc_tm->tm_min = readb(S3C2410_RTCMIN); + rtc_tm->tm_hour = readb(S3C2410_RTCHOUR); + rtc_tm->tm_mday = readb(S3C2410_RTCDATE); + rtc_tm->tm_mon = readb(S3C2410_RTCMON); + rtc_tm->tm_year = readb(S3C2410_RTCYEAR); + rtc_tm->tm_sec = readb(S3C2410_RTCSEC); + + /* the only way to work out wether the system was mid-update + * when we read it is to check the second counter, and if it + * is zero, then we re-try the entire read + */ + + if (rtc_tm->tm_sec == 0 && !have_retried) { + have_retried = 1; + goto retry_get_time; + } + + pr_debug("read time %02x.%02x.%02x %02x/%02x/%02x\n", + rtc_tm->tm_year, rtc_tm->tm_mon, rtc_tm->tm_mday, + rtc_tm->tm_hour, rtc_tm->tm_min, rtc_tm->tm_sec); + + BCD_TO_BIN(rtc_tm->tm_sec); + BCD_TO_BIN(rtc_tm->tm_min); + BCD_TO_BIN(rtc_tm->tm_hour); + BCD_TO_BIN(rtc_tm->tm_mday); + BCD_TO_BIN(rtc_tm->tm_mon); + BCD_TO_BIN(rtc_tm->tm_year); + + rtc_tm->tm_year += 100; + rtc_tm->tm_mon -= 1; +} + + +static int s3c2410_rtc_settime(struct rtc_time *tm) +{ + /* the rtc gets round the y2k problem by just not supporting it */ + + if (tm->tm_year < 100) + return -EINVAL; + + writeb(BIN2BCD(tm->tm_sec), S3C2410_RTCSEC); + writeb(BIN2BCD(tm->tm_min), S3C2410_RTCMIN); + writeb(BIN2BCD(tm->tm_hour), S3C2410_RTCHOUR); + writeb(BIN2BCD(tm->tm_mday), S3C2410_RTCDATE); + writeb(BIN2BCD(tm->tm_mon + 1), S3C2410_RTCMON); + writeb(BIN2BCD(tm->tm_year - 100), S3C2410_RTCYEAR); + + return 0; +} + +static void s3c2410_rtc_getalarm(struct rtc_wkalrm *alrm) +{ + struct rtc_time *alm_tm = &alrm->time; + unsigned int alm_en; + + alm_tm->tm_sec = readb(S3C2410_ALMSEC); + alm_tm->tm_min = readb(S3C2410_ALMMIN); + alm_tm->tm_hour = readb(S3C2410_ALMHOUR); + alm_tm->tm_mon = readb(S3C2410_ALMMON); + alm_tm->tm_mday = readb(S3C2410_ALMDATE); + alm_tm->tm_year = readb(S3C2410_ALMYEAR); + + alm_en = readb(S3C2410_RTCALM); + + pr_debug("read alarm %02x %02x.%02x.%02x %02x/%02x/%02x\n", + alm_en, + alm_tm->tm_year, alm_tm->tm_mon, alm_tm->tm_mday, + alm_tm->tm_hour, alm_tm->tm_min, alm_tm->tm_sec); + + + /* decode the alarm enable field */ + + if (alm_en & S3C2410_RTCALM_SECEN) { + BCD_TO_BIN(alm_tm->tm_sec); + } else { + alm_tm->tm_sec = 0xff; + } + + if (alm_en & S3C2410_RTCALM_MINEN) { + BCD_TO_BIN(alm_tm->tm_min); + } else { + alm_tm->tm_min = 0xff; + } + + if (alm_en & S3C2410_RTCALM_HOUREN) { + BCD_TO_BIN(alm_tm->tm_hour); + } else { + alm_tm->tm_hour = 0xff; + } + + if (alm_en & S3C2410_RTCALM_DAYEN) { + BCD_TO_BIN(alm_tm->tm_mday); + } else { + alm_tm->tm_mday = 0xff; + } + + if (alm_en & S3C2410_RTCALM_MONEN) { + BCD_TO_BIN(alm_tm->tm_mon); + alm_tm->tm_mon -= 1; + } else { + alm_tm->tm_mon = 0xff; + } + + if (alm_en & S3C2410_RTCALM_YEAREN) { + BCD_TO_BIN(alm_tm->tm_year); + } else { + alm_tm->tm_year = 0xffff; + } + + /* todo - set alrm->enabled ? */ +} + +static int s3c2410_rtc_setalarm(struct rtc_wkalrm *alrm) +{ + struct rtc_time *tm = &alrm->time; + unsigned int alrm_en; + + pr_debug("s3c2410_rtc_setalarm: %d, %02x/%02x/%02x %02x.%02x.%02x\n", + alrm->enabled, + tm->tm_mday & 0xff, tm->tm_mon & 0xff, tm->tm_year & 0xff, + tm->tm_hour & 0xff, tm->tm_min & 0xff, tm->tm_sec); + + if (alrm->enabled || 1) { + alrm_en = readb(S3C2410_RTCALM) & S3C2410_RTCALM_ALMEN; + writeb(0x00, S3C2410_RTCALM); + + if (tm->tm_sec < 60 && tm->tm_sec >= 0) { + alrm_en |= S3C2410_RTCALM_SECEN; + writeb(BIN2BCD(tm->tm_sec), S3C2410_ALMSEC); + } + + if (tm->tm_min < 60 && tm->tm_min >= 0) { + alrm_en |= S3C2410_RTCALM_MINEN; + writeb(BIN2BCD(tm->tm_min), S3C2410_ALMMIN); + } + + if (tm->tm_hour < 24 && tm->tm_hour >= 0) { + alrm_en |= S3C2410_RTCALM_HOUREN; + writeb(BIN2BCD(tm->tm_hour), S3C2410_ALMHOUR); + } + + pr_debug("setting S3C2410_RTCALM to %08x\n", alrm_en); + + writeb(alrm_en, S3C2410_RTCALM); + enable_irq_wake(s3c2410_rtc_alarmno); + } else { + alrm_en = readb(S3C2410_RTCALM); + alrm_en &= ~S3C2410_RTCALM_ALMEN; + writeb(alrm_en, S3C2410_RTCALM); + disable_irq_wake(s3c2410_rtc_alarmno); + } + + return 0; +} + +static int s3c2410_rtc_ioctl(unsigned int cmd, unsigned long arg) +{ + switch (cmd) { + case RTC_AIE_OFF: + case RTC_AIE_ON: + s3c2410_rtc_setaie((cmd == RTC_AIE_ON) ? 1 : 0); + return 0; + + case RTC_PIE_OFF: + case RTC_PIE_ON: + s3c2410_rtc_setpie((cmd == RTC_PIE_ON) ? 1 : 0); + return 0; + + case RTC_IRQP_READ: + return put_user(s3c2410_rtc_freq, (unsigned long __user *)arg); + + case RTC_IRQP_SET: + if (arg < 1 || arg > 64) + return -EINVAL; + + if (!capable(CAP_SYS_RESOURCE)) + return -EACCES; + + /* check for power of 2 */ + + if ((arg & (arg-1)) != 0) + return -EINVAL; + + pr_debug("s3c2410_rtc: setting frequency %ld\n", arg); + + s3c2410_rtc_setfreq(arg); + return 0; + + case RTC_UIE_ON: + case RTC_UIE_OFF: + return -EINVAL; + } + + return -EINVAL; +} + +static int s3c2410_rtc_proc(char *buf) +{ + unsigned int rtcalm = readb(S3C2410_RTCALM); + unsigned int ticnt = readb (S3C2410_TICNT); + char *p = buf; + + p += sprintf(p, "alarm_IRQ\t: %s\n", + (rtcalm & S3C2410_RTCALM_ALMEN) ? "yes" : "no" ); + p += sprintf(p, "periodic_IRQ\t: %s\n", + (ticnt & S3C2410_TICNT_ENABLE) ? "yes" : "no" ); + p += sprintf(p, "periodic_freq\t: %d\n", s3c2410_rtc_freq); + + return p - buf; +} + +static int s3c2410_rtc_open(void) +{ + int ret; + + ret = request_irq(s3c2410_rtc_alarmno, s3c2410_rtc_alarmirq, + SA_INTERRUPT, "s3c2410-rtc alarm", NULL); + + if (ret) + printk(KERN_ERR "IRQ%d already in use\n", s3c2410_rtc_alarmno); + + ret = request_irq(s3c2410_rtc_tickno, s3c2410_rtc_tickirq, + SA_INTERRUPT, "s3c2410-rtc tick", NULL); + + if (ret) { + printk(KERN_ERR "IRQ%d already in use\n", s3c2410_rtc_tickno); + goto tick_err; + } + + return ret; + + tick_err: + free_irq(s3c2410_rtc_alarmno, NULL); + return ret; +} + +static void s3c2410_rtc_release(void) +{ + /* do not clear AIE here, it may be needed for wake */ + + s3c2410_rtc_setpie(0); + free_irq(s3c2410_rtc_alarmno, NULL); + free_irq(s3c2410_rtc_tickno, NULL); +} + +static struct rtc_ops s3c2410_rtcops = { + .owner = THIS_MODULE, + .open = s3c2410_rtc_open, + .release = s3c2410_rtc_release, + .ioctl = s3c2410_rtc_ioctl, + .read_time = s3c2410_rtc_gettime, + .set_time = s3c2410_rtc_settime, + .read_alarm = s3c2410_rtc_getalarm, + .set_alarm = s3c2410_rtc_setalarm, + .proc = s3c2410_rtc_proc, +}; + +static void s3c2410_rtc_enable(struct device *dev, int en) +{ + unsigned int tmp; + + if (s3c2410_rtc_base == NULL) + return; + + if (!en) { + tmp = readb(S3C2410_RTCCON); + writeb(tmp & ~S3C2410_RTCCON_RTCEN, S3C2410_RTCCON); + + tmp = readb(S3C2410_TICNT); + writeb(tmp & ~S3C2410_TICNT_ENABLE, S3C2410_TICNT); + } else { + /* re-enable the device, and check it is ok */ + + if ((readb(S3C2410_RTCCON) & S3C2410_RTCCON_RTCEN) == 0){ + dev_info(dev, "rtc disabled, re-enabling\n"); + + tmp = readb(S3C2410_RTCCON); + writeb(tmp | S3C2410_RTCCON_RTCEN , S3C2410_RTCCON); + } + + if ((readb(S3C2410_RTCCON) & S3C2410_RTCCON_CNTSEL)){ + dev_info(dev, "removing S3C2410_RTCCON_CNTSEL\n"); + + tmp = readb(S3C2410_RTCCON); + writeb(tmp& ~S3C2410_RTCCON_CNTSEL , S3C2410_RTCCON); + } + + if ((readb(S3C2410_RTCCON) & S3C2410_RTCCON_CLKRST)){ + dev_info(dev, "removing S3C2410_RTCCON_CLKRST\n"); + + tmp = readb(S3C2410_RTCCON); + writeb(tmp & ~S3C2410_RTCCON_CLKRST, S3C2410_RTCCON); + } + } +} + +static int s3c2410_rtc_remove(struct device *dev) +{ + unregister_rtc(&s3c2410_rtcops); + + s3c2410_rtc_setpie(0); + s3c2410_rtc_setaie(0); + + if (s3c2410_rtc_mem != NULL) { + pr_debug("s3c2410_rtc: releasing s3c2410_rtc_mem\n"); + iounmap(s3c2410_rtc_base); + release_resource(s3c2410_rtc_mem); + kfree(s3c2410_rtc_mem); + } + + return 0; +} + +static int s3c2410_rtc_probe(struct device *dev) +{ + struct platform_device *pdev = to_platform_device(dev); + struct resource *res; + int ret; + + pr_debug("%s: probe=%p, device=%p\n", __FUNCTION__, pdev, dev); + + /* find the IRQs */ + + s3c2410_rtc_tickno = platform_get_irq(pdev, 1); + if (s3c2410_rtc_tickno <= 0) { + dev_err(dev, "no irq for rtc tick\n"); + return -ENOENT; + } + + s3c2410_rtc_alarmno = platform_get_irq(pdev, 0); + if (s3c2410_rtc_alarmno <= 0) { + dev_err(dev, "no irq for alarm\n"); + return -ENOENT; + } + + pr_debug("s3c2410_rtc: tick irq %d, alarm irq %d\n", + s3c2410_rtc_tickno, s3c2410_rtc_alarmno); + + /* get the memory region */ + + res = platform_get_resource(pdev, IORESOURCE_MEM, 0); + if (res == NULL) { + dev_err(dev, "failed to get memory region resource\n"); + return -ENOENT; + } + + s3c2410_rtc_mem = request_mem_region(res->start, res->end-res->start+1, + pdev->name); + + if (s3c2410_rtc_mem == NULL) { + dev_err(dev, "failed to reserve memory region\n"); + ret = -ENOENT; + goto exit_err; + } + + s3c2410_rtc_base = ioremap(res->start, res->end - res->start + 1); + if (s3c2410_rtc_base == NULL) { + dev_err(dev, "failed ioremap()\n"); + ret = -EINVAL; + goto exit_err; + } + + s3c2410_rtc_mem = res; + pr_debug("s3c2410_rtc_base=%p\n", s3c2410_rtc_base); + + pr_debug("s3c2410_rtc: RTCCON=%02x\n", readb(S3C2410_RTCCON)); + + /* check to see if everything is setup correctly */ + + s3c2410_rtc_enable(dev, 1); + + pr_debug("s3c2410_rtc: RTCCON=%02x\n", readb(S3C2410_RTCCON)); + + s3c2410_rtc_setfreq(s3c2410_rtc_freq); + + /* register RTC and exit */ + + register_rtc(&s3c2410_rtcops); + return 0; + + exit_err: + dev_err(dev, "error %d during initialisation\n", ret); + + return ret; +} + +#ifdef CONFIG_PM + +/* S3C2410 RTC Power management control */ + +static struct timespec s3c2410_rtc_delta; + +static int ticnt_save; + +static int s3c2410_rtc_suspend(struct device *dev, u32 state, u32 level) +{ + struct rtc_time tm; + struct timespec time; + + time.tv_nsec = 0; + + if (level == SUSPEND_POWER_DOWN) { + /* save TICNT for anyone using periodic interrupts */ + + ticnt_save = readb(S3C2410_TICNT); + + /* calculate time delta for suspend */ + + s3c2410_rtc_gettime(&tm); + rtc_tm_to_time(&tm, &time.tv_sec); + save_time_delta(&s3c2410_rtc_delta, &time); + s3c2410_rtc_enable(dev, 0); + } + + return 0; +} + +static int s3c2410_rtc_resume(struct device *dev, u32 level) +{ + struct rtc_time tm; + struct timespec time; + + time.tv_nsec = 0; + + s3c2410_rtc_enable(dev, 1); + s3c2410_rtc_gettime(&tm); + rtc_tm_to_time(&tm, &time.tv_sec); + restore_time_delta(&s3c2410_rtc_delta, &time); + + writeb(ticnt_save, S3C2410_TICNT); + return 0; +} +#else +#define s3c2410_rtc_suspend NULL +#define s3c2410_rtc_resume NULL +#endif + +static struct device_driver s3c2410_rtcdrv = { + .name = "s3c2410-rtc", + .bus = &platform_bus_type, + .probe = s3c2410_rtc_probe, + .remove = s3c2410_rtc_remove, + .suspend = s3c2410_rtc_suspend, + .resume = s3c2410_rtc_resume, +}; + +static char __initdata banner[] = "S3C2410 RTC, (c) 2004 Simtec Electronics\n"; + +static int __init s3c2410_rtc_init(void) +{ + printk(banner); + return driver_register(&s3c2410_rtcdrv); +} + +static void __exit s3c2410_rtc_exit(void) +{ + driver_unregister(&s3c2410_rtcdrv); +} + +module_init(s3c2410_rtc_init); +module_exit(s3c2410_rtc_exit); + +MODULE_DESCRIPTION("S3C24XX RTC Driver"); +MODULE_AUTHOR("Ben Dooks, <ben@simtec.co.uk>"); +MODULE_LICENSE("GPL"); |