linux/drivers/rtc/rtc-sh.c

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/*
* SuperH On-Chip RTC Support
*
* Copyright (C) 2006, 2007 Paul Mundt
* Copyright (C) 2006 Jamie Lenehan
*
* Based on the old arch/sh/kernel/cpu/rtc.c by:
*
* Copyright (C) 2000 Philipp Rumpf <prumpf@tux.org>
* Copyright (C) 1999 Tetsuya Okada & Niibe Yutaka
*
* This file is subject to the terms and conditions of the GNU General Public
* License. See the file "COPYING" in the main directory of this archive
* for more details.
*/
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/bcd.h>
#include <linux/rtc.h>
#include <linux/init.h>
#include <linux/platform_device.h>
#include <linux/seq_file.h>
#include <linux/interrupt.h>
#include <linux/spinlock.h>
#include <linux/io.h>
#include <asm/rtc.h>
#define DRV_NAME "sh-rtc"
#define DRV_VERSION "0.1.3"
#ifdef CONFIG_CPU_SH3
#define rtc_reg_size sizeof(u16)
#define RTC_BIT_INVERTED 0 /* No bug on SH7708, SH7709A */
#define RTC_DEF_CAPABILITIES 0UL
#elif defined(CONFIG_CPU_SH4)
#define rtc_reg_size sizeof(u32)
#define RTC_BIT_INVERTED 0x40 /* bug on SH7750, SH7750S */
#define RTC_DEF_CAPABILITIES RTC_CAP_4_DIGIT_YEAR
#endif
#define RTC_REG(r) ((r) * rtc_reg_size)
#define R64CNT RTC_REG(0)
#define RSECCNT RTC_REG(1) /* RTC sec */
#define RMINCNT RTC_REG(2) /* RTC min */
#define RHRCNT RTC_REG(3) /* RTC hour */
#define RWKCNT RTC_REG(4) /* RTC week */
#define RDAYCNT RTC_REG(5) /* RTC day */
#define RMONCNT RTC_REG(6) /* RTC month */
#define RYRCNT RTC_REG(7) /* RTC year */
#define RSECAR RTC_REG(8) /* ALARM sec */
#define RMINAR RTC_REG(9) /* ALARM min */
#define RHRAR RTC_REG(10) /* ALARM hour */
#define RWKAR RTC_REG(11) /* ALARM week */
#define RDAYAR RTC_REG(12) /* ALARM day */
#define RMONAR RTC_REG(13) /* ALARM month */
#define RCR1 RTC_REG(14) /* Control */
#define RCR2 RTC_REG(15) /* Control */
/* ALARM Bits - or with BCD encoded value */
#define AR_ENB 0x80 /* Enable for alarm cmp */
/* RCR1 Bits */
#define RCR1_CF 0x80 /* Carry Flag */
#define RCR1_CIE 0x10 /* Carry Interrupt Enable */
#define RCR1_AIE 0x08 /* Alarm Interrupt Enable */
#define RCR1_AF 0x01 /* Alarm Flag */
/* RCR2 Bits */
#define RCR2_PEF 0x80 /* PEriodic interrupt Flag */
#define RCR2_PESMASK 0x70 /* Periodic interrupt Set */
#define RCR2_RTCEN 0x08 /* ENable RTC */
#define RCR2_ADJ 0x04 /* ADJustment (30-second) */
#define RCR2_RESET 0x02 /* Reset bit */
#define RCR2_START 0x01 /* Start bit */
struct sh_rtc {
void __iomem *regbase;
unsigned long regsize;
struct resource *res;
unsigned int alarm_irq, periodic_irq, carry_irq;
struct rtc_device *rtc_dev;
spinlock_t lock;
int rearm_aie;
unsigned long capabilities; /* See asm-sh/rtc.h for cap bits */
};
static irqreturn_t sh_rtc_interrupt(int irq, void *dev_id)
{
struct platform_device *pdev = to_platform_device(dev_id);
struct sh_rtc *rtc = platform_get_drvdata(pdev);
unsigned int tmp, events = 0;
spin_lock(&rtc->lock);
tmp = readb(rtc->regbase + RCR1);
tmp &= ~RCR1_CF;
if (rtc->rearm_aie) {
if (tmp & RCR1_AF)
tmp &= ~RCR1_AF; /* try to clear AF again */
else {
tmp |= RCR1_AIE; /* AF has cleared, rearm IRQ */
rtc->rearm_aie = 0;
}
}
writeb(tmp, rtc->regbase + RCR1);
rtc_update_irq(rtc->rtc_dev, 1, events);
spin_unlock(&rtc->lock);
return IRQ_HANDLED;
}
static irqreturn_t sh_rtc_alarm(int irq, void *dev_id)
{
struct platform_device *pdev = to_platform_device(dev_id);
struct sh_rtc *rtc = platform_get_drvdata(pdev);
unsigned int tmp, events = 0;
spin_lock(&rtc->lock);
tmp = readb(rtc->regbase + RCR1);
/*
* If AF is set then the alarm has triggered. If we clear AF while
* the alarm time still matches the RTC time then AF will
* immediately be set again, and if AIE is enabled then the alarm
* interrupt will immediately be retrigger. So we clear AIE here
* and use rtc->rearm_aie so that the carry interrupt will keep
* trying to clear AF and once it stays cleared it'll re-enable
* AIE.
*/
if (tmp & RCR1_AF) {
events |= RTC_AF | RTC_IRQF;
tmp &= ~(RCR1_AF|RCR1_AIE);
writeb(tmp, rtc->regbase + RCR1);
rtc->rearm_aie = 1;
rtc_update_irq(rtc->rtc_dev, 1, events);
}
spin_unlock(&rtc->lock);
return IRQ_HANDLED;
}
static irqreturn_t sh_rtc_periodic(int irq, void *dev_id)
{
struct platform_device *pdev = to_platform_device(dev_id);
struct sh_rtc *rtc = platform_get_drvdata(pdev);
spin_lock(&rtc->lock);
rtc_update_irq(rtc->rtc_dev, 1, RTC_PF | RTC_IRQF);
spin_unlock(&rtc->lock);
return IRQ_HANDLED;
}
static inline void sh_rtc_setpie(struct device *dev, unsigned int enable)
{
struct sh_rtc *rtc = dev_get_drvdata(dev);
unsigned int tmp;
spin_lock_irq(&rtc->lock);
tmp = readb(rtc->regbase + RCR2);
if (enable) {
tmp &= ~RCR2_PESMASK;
tmp |= RCR2_PEF | (2 << 4);
} else
tmp &= ~(RCR2_PESMASK | RCR2_PEF);
writeb(tmp, rtc->regbase + RCR2);
spin_unlock_irq(&rtc->lock);
}
static inline void sh_rtc_setaie(struct device *dev, unsigned int enable)
{
struct sh_rtc *rtc = dev_get_drvdata(dev);
unsigned int tmp;
spin_lock_irq(&rtc->lock);
tmp = readb(rtc->regbase + RCR1);
if (!enable) {
tmp &= ~RCR1_AIE;
rtc->rearm_aie = 0;
} else if (rtc->rearm_aie == 0)
tmp |= RCR1_AIE;
writeb(tmp, rtc->regbase + RCR1);
spin_unlock_irq(&rtc->lock);
}
static int sh_rtc_open(struct device *dev)
{
struct sh_rtc *rtc = dev_get_drvdata(dev);
unsigned int tmp;
int ret;
tmp = readb(rtc->regbase + RCR1);
tmp &= ~RCR1_CF;
tmp |= RCR1_CIE;
writeb(tmp, rtc->regbase + RCR1);
ret = request_irq(rtc->periodic_irq, sh_rtc_periodic, IRQF_DISABLED,
"sh-rtc period", dev);
if (unlikely(ret)) {
dev_err(dev, "request period IRQ failed with %d, IRQ %d\n",
ret, rtc->periodic_irq);
return ret;
}
ret = request_irq(rtc->carry_irq, sh_rtc_interrupt, IRQF_DISABLED,
"sh-rtc carry", dev);
if (unlikely(ret)) {
dev_err(dev, "request carry IRQ failed with %d, IRQ %d\n",
ret, rtc->carry_irq);
free_irq(rtc->periodic_irq, dev);
goto err_bad_carry;
}
ret = request_irq(rtc->alarm_irq, sh_rtc_alarm, IRQF_DISABLED,
"sh-rtc alarm", dev);
if (unlikely(ret)) {
dev_err(dev, "request alarm IRQ failed with %d, IRQ %d\n",
ret, rtc->alarm_irq);
goto err_bad_alarm;
}
return 0;
err_bad_alarm:
free_irq(rtc->carry_irq, dev);
err_bad_carry:
free_irq(rtc->periodic_irq, dev);
return ret;
}
static void sh_rtc_release(struct device *dev)
{
struct sh_rtc *rtc = dev_get_drvdata(dev);
sh_rtc_setpie(dev, 0);
sh_rtc_setaie(dev, 0);
free_irq(rtc->periodic_irq, dev);
free_irq(rtc->carry_irq, dev);
free_irq(rtc->alarm_irq, dev);
}
static int sh_rtc_proc(struct device *dev, struct seq_file *seq)
{
struct sh_rtc *rtc = dev_get_drvdata(dev);
unsigned int tmp;
tmp = readb(rtc->regbase + RCR1);
seq_printf(seq, "carry_IRQ\t: %s\n",
(tmp & RCR1_CIE) ? "yes" : "no");
tmp = readb(rtc->regbase + RCR2);
seq_printf(seq, "periodic_IRQ\t: %s\n",
(tmp & RCR2_PEF) ? "yes" : "no");
return 0;
}
static int sh_rtc_ioctl(struct device *dev, unsigned int cmd, unsigned long arg)
{
unsigned int ret = -ENOIOCTLCMD;
switch (cmd) {
case RTC_PIE_OFF:
case RTC_PIE_ON:
sh_rtc_setpie(dev, cmd == RTC_PIE_ON);
ret = 0;
break;
case RTC_AIE_OFF:
case RTC_AIE_ON:
sh_rtc_setaie(dev, cmd == RTC_AIE_ON);
ret = 0;
break;
}
return ret;
}
static int sh_rtc_read_time(struct device *dev, struct rtc_time *tm)
{
struct platform_device *pdev = to_platform_device(dev);
struct sh_rtc *rtc = platform_get_drvdata(pdev);
unsigned int sec128, sec2, yr, yr100, cf_bit;
do {
unsigned int tmp;
spin_lock_irq(&rtc->lock);
tmp = readb(rtc->regbase + RCR1);
tmp &= ~RCR1_CF; /* Clear CF-bit */
tmp |= RCR1_CIE;
writeb(tmp, rtc->regbase + RCR1);
sec128 = readb(rtc->regbase + R64CNT);
tm->tm_sec = BCD2BIN(readb(rtc->regbase + RSECCNT));
tm->tm_min = BCD2BIN(readb(rtc->regbase + RMINCNT));
tm->tm_hour = BCD2BIN(readb(rtc->regbase + RHRCNT));
tm->tm_wday = BCD2BIN(readb(rtc->regbase + RWKCNT));
tm->tm_mday = BCD2BIN(readb(rtc->regbase + RDAYCNT));
tm->tm_mon = BCD2BIN(readb(rtc->regbase + RMONCNT)) - 1;
if (rtc->capabilities & RTC_CAP_4_DIGIT_YEAR) {
yr = readw(rtc->regbase + RYRCNT);
yr100 = BCD2BIN(yr >> 8);
yr &= 0xff;
} else {
yr = readb(rtc->regbase + RYRCNT);
yr100 = BCD2BIN((yr == 0x99) ? 0x19 : 0x20);
}
tm->tm_year = (yr100 * 100 + BCD2BIN(yr)) - 1900;
sec2 = readb(rtc->regbase + R64CNT);
cf_bit = readb(rtc->regbase + RCR1) & RCR1_CF;
spin_unlock_irq(&rtc->lock);
} while (cf_bit != 0 || ((sec128 ^ sec2) & RTC_BIT_INVERTED) != 0);
#if RTC_BIT_INVERTED != 0
if ((sec128 & RTC_BIT_INVERTED))
tm->tm_sec--;
#endif
dev_dbg(dev, "%s: tm is secs=%d, mins=%d, hours=%d, "
"mday=%d, mon=%d, year=%d, wday=%d\n",
__FUNCTION__,
tm->tm_sec, tm->tm_min, tm->tm_hour,
tm->tm_mday, tm->tm_mon + 1, tm->tm_year, tm->tm_wday);
if (rtc_valid_tm(tm) < 0)
dev_err(dev, "invalid date\n");
return 0;
}
static int sh_rtc_set_time(struct device *dev, struct rtc_time *tm)
{
struct platform_device *pdev = to_platform_device(dev);
struct sh_rtc *rtc = platform_get_drvdata(pdev);
unsigned int tmp;
int year;
spin_lock_irq(&rtc->lock);
/* Reset pre-scaler & stop RTC */
tmp = readb(rtc->regbase + RCR2);
tmp |= RCR2_RESET;
tmp &= ~RCR2_START;
writeb(tmp, rtc->regbase + RCR2);
writeb(BIN2BCD(tm->tm_sec), rtc->regbase + RSECCNT);
writeb(BIN2BCD(tm->tm_min), rtc->regbase + RMINCNT);
writeb(BIN2BCD(tm->tm_hour), rtc->regbase + RHRCNT);
writeb(BIN2BCD(tm->tm_wday), rtc->regbase + RWKCNT);
writeb(BIN2BCD(tm->tm_mday), rtc->regbase + RDAYCNT);
writeb(BIN2BCD(tm->tm_mon + 1), rtc->regbase + RMONCNT);
if (rtc->capabilities & RTC_CAP_4_DIGIT_YEAR) {
year = (BIN2BCD((tm->tm_year + 1900) / 100) << 8) |
BIN2BCD(tm->tm_year % 100);
writew(year, rtc->regbase + RYRCNT);
} else {
year = tm->tm_year % 100;
writeb(BIN2BCD(year), rtc->regbase + RYRCNT);
}
/* Start RTC */
tmp = readb(rtc->regbase + RCR2);
tmp &= ~RCR2_RESET;
tmp |= RCR2_RTCEN | RCR2_START;
writeb(tmp, rtc->regbase + RCR2);
spin_unlock_irq(&rtc->lock);
return 0;
}
static inline int sh_rtc_read_alarm_value(struct sh_rtc *rtc, int reg_off)
{
unsigned int byte;
int value = 0xff; /* return 0xff for ignored values */
byte = readb(rtc->regbase + reg_off);
if (byte & AR_ENB) {
byte &= ~AR_ENB; /* strip the enable bit */
value = BCD2BIN(byte);
}
return value;
}
static int sh_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *wkalrm)
{
struct platform_device *pdev = to_platform_device(dev);
struct sh_rtc *rtc = platform_get_drvdata(pdev);
struct rtc_time* tm = &wkalrm->time;
spin_lock_irq(&rtc->lock);
tm->tm_sec = sh_rtc_read_alarm_value(rtc, RSECAR);
tm->tm_min = sh_rtc_read_alarm_value(rtc, RMINAR);
tm->tm_hour = sh_rtc_read_alarm_value(rtc, RHRAR);
tm->tm_wday = sh_rtc_read_alarm_value(rtc, RWKAR);
tm->tm_mday = sh_rtc_read_alarm_value(rtc, RDAYAR);
tm->tm_mon = sh_rtc_read_alarm_value(rtc, RMONAR);
if (tm->tm_mon > 0)
tm->tm_mon -= 1; /* RTC is 1-12, tm_mon is 0-11 */
tm->tm_year = 0xffff;
wkalrm->enabled = (readb(rtc->regbase + RCR1) & RCR1_AIE) ? 1 : 0;
spin_unlock_irq(&rtc->lock);
return 0;
}
static inline void sh_rtc_write_alarm_value(struct sh_rtc *rtc,
int value, int reg_off)
{
/* < 0 for a value that is ignored */
if (value < 0)
writeb(0, rtc->regbase + reg_off);
else
writeb(BIN2BCD(value) | AR_ENB, rtc->regbase + reg_off);
}
static int sh_rtc_check_alarm(struct rtc_time* tm)
{
/*
* The original rtc says anything > 0xc0 is "don't care" or "match
* all" - most users use 0xff but rtc-dev uses -1 for the same thing.
* The original rtc doesn't support years - some things use -1 and
* some 0xffff. We use -1 to make out tests easier.
*/
if (tm->tm_year == 0xffff)
tm->tm_year = -1;
if (tm->tm_mon >= 0xff)
tm->tm_mon = -1;
if (tm->tm_mday >= 0xff)
tm->tm_mday = -1;
if (tm->tm_wday >= 0xff)
tm->tm_wday = -1;
if (tm->tm_hour >= 0xff)
tm->tm_hour = -1;
if (tm->tm_min >= 0xff)
tm->tm_min = -1;
if (tm->tm_sec >= 0xff)
tm->tm_sec = -1;
if (tm->tm_year > 9999 ||
tm->tm_mon >= 12 ||
tm->tm_mday == 0 || tm->tm_mday >= 32 ||
tm->tm_wday >= 7 ||
tm->tm_hour >= 24 ||
tm->tm_min >= 60 ||
tm->tm_sec >= 60)
return -EINVAL;
return 0;
}
static int sh_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *wkalrm)
{
struct platform_device *pdev = to_platform_device(dev);
struct sh_rtc *rtc = platform_get_drvdata(pdev);
unsigned int rcr1;
struct rtc_time *tm = &wkalrm->time;
int mon, err;
err = sh_rtc_check_alarm(tm);
if (unlikely(err < 0))
return err;
spin_lock_irq(&rtc->lock);
/* disable alarm interrupt and clear the alarm flag */
rcr1 = readb(rtc->regbase + RCR1);
rcr1 &= ~(RCR1_AF|RCR1_AIE);
writeb(rcr1, rtc->regbase + RCR1);
rtc->rearm_aie = 0;
/* set alarm time */
sh_rtc_write_alarm_value(rtc, tm->tm_sec, RSECAR);
sh_rtc_write_alarm_value(rtc, tm->tm_min, RMINAR);
sh_rtc_write_alarm_value(rtc, tm->tm_hour, RHRAR);
sh_rtc_write_alarm_value(rtc, tm->tm_wday, RWKAR);
sh_rtc_write_alarm_value(rtc, tm->tm_mday, RDAYAR);
mon = tm->tm_mon;
if (mon >= 0)
mon += 1;
sh_rtc_write_alarm_value(rtc, mon, RMONAR);
if (wkalrm->enabled) {
rcr1 |= RCR1_AIE;
writeb(rcr1, rtc->regbase + RCR1);
}
spin_unlock_irq(&rtc->lock);
return 0;
}
static struct rtc_class_ops sh_rtc_ops = {
.open = sh_rtc_open,
.release = sh_rtc_release,
.ioctl = sh_rtc_ioctl,
.read_time = sh_rtc_read_time,
.set_time = sh_rtc_set_time,
.read_alarm = sh_rtc_read_alarm,
.set_alarm = sh_rtc_set_alarm,
.proc = sh_rtc_proc,
};
static int __devinit sh_rtc_probe(struct platform_device *pdev)
{
struct sh_rtc *rtc;
struct resource *res;
int ret = -ENOENT;
rtc = kzalloc(sizeof(struct sh_rtc), GFP_KERNEL);
if (unlikely(!rtc))
return -ENOMEM;
spin_lock_init(&rtc->lock);
rtc->periodic_irq = platform_get_irq(pdev, 0);
if (unlikely(rtc->periodic_irq < 0)) {
dev_err(&pdev->dev, "No IRQ for period\n");
goto err_badres;
}
rtc->carry_irq = platform_get_irq(pdev, 1);
if (unlikely(rtc->carry_irq < 0)) {
dev_err(&pdev->dev, "No IRQ for carry\n");
goto err_badres;
}
rtc->alarm_irq = platform_get_irq(pdev, 2);
if (unlikely(rtc->alarm_irq < 0)) {
dev_err(&pdev->dev, "No IRQ for alarm\n");
goto err_badres;
}
res = platform_get_resource(pdev, IORESOURCE_IO, 0);
if (unlikely(res == NULL)) {
dev_err(&pdev->dev, "No IO resource\n");
goto err_badres;
}
rtc->regsize = res->end - res->start + 1;
rtc->res = request_mem_region(res->start, rtc->regsize, pdev->name);
if (unlikely(!rtc->res)) {
ret = -EBUSY;
goto err_badres;
}
rtc->regbase = (void __iomem *)rtc->res->start;
if (unlikely(!rtc->regbase)) {
ret = -EINVAL;
goto err_badmap;
}
rtc->rtc_dev = rtc_device_register("sh", &pdev->dev,
&sh_rtc_ops, THIS_MODULE);
if (IS_ERR(rtc)) {
ret = PTR_ERR(rtc->rtc_dev);
goto err_badmap;
}
rtc->capabilities = RTC_DEF_CAPABILITIES;
if (pdev->dev.platform_data) {
struct sh_rtc_platform_info *pinfo = pdev->dev.platform_data;
/*
* Some CPUs have special capabilities in addition to the
* default set. Add those in here.
*/
rtc->capabilities |= pinfo->capabilities;
}
platform_set_drvdata(pdev, rtc);
return 0;
err_badmap:
release_resource(rtc->res);
err_badres:
kfree(rtc);
return ret;
}
static int __devexit sh_rtc_remove(struct platform_device *pdev)
{
struct sh_rtc *rtc = platform_get_drvdata(pdev);
if (likely(rtc->rtc_dev))
rtc_device_unregister(rtc->rtc_dev);
sh_rtc_setpie(&pdev->dev, 0);
sh_rtc_setaie(&pdev->dev, 0);
release_resource(rtc->res);
platform_set_drvdata(pdev, NULL);
kfree(rtc);
return 0;
}
static struct platform_driver sh_rtc_platform_driver = {
.driver = {
.name = DRV_NAME,
.owner = THIS_MODULE,
},
.probe = sh_rtc_probe,
.remove = __devexit_p(sh_rtc_remove),
};
static int __init sh_rtc_init(void)
{
return platform_driver_register(&sh_rtc_platform_driver);
}
static void __exit sh_rtc_exit(void)
{
platform_driver_unregister(&sh_rtc_platform_driver);
}
module_init(sh_rtc_init);
module_exit(sh_rtc_exit);
MODULE_DESCRIPTION("SuperH on-chip RTC driver");
MODULE_VERSION(DRV_VERSION);
MODULE_AUTHOR("Paul Mundt <lethal@linux-sh.org>, Jamie Lenehan <lenehan@twibble.org>");
MODULE_LICENSE("GPL");