/*
* Real-time clock driver for MPC5121
*
* Copyright 2007, Domen Puncer <domen.puncer@telargo.com>
* Copyright 2008, Freescale Semiconductor, Inc. All rights reserved.
*
* 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.
*/
#include <linux/init.h>
#include <linux/module.h>
#include <linux/rtc.h>
#include <linux/of_device.h>
#include <linux/of_platform.h>
#include <linux/io.h>
#include <linux/slab.h>
struct mpc5121_rtc_regs {
u8 set_time; /* RTC + 0x00 */
u8 hour_set; /* RTC + 0x01 */
u8 minute_set; /* RTC + 0x02 */
u8 second_set; /* RTC + 0x03 */
u8 set_date; /* RTC + 0x04 */
u8 month_set; /* RTC + 0x05 */
u8 weekday_set; /* RTC + 0x06 */
u8 date_set; /* RTC + 0x07 */
u8 write_sw; /* RTC + 0x08 */
u8 sw_set; /* RTC + 0x09 */
u16 year_set; /* RTC + 0x0a */
u8 alm_enable; /* RTC + 0x0c */
u8 alm_hour_set; /* RTC + 0x0d */
u8 alm_min_set; /* RTC + 0x0e */
u8 int_enable; /* RTC + 0x0f */
u8 reserved1;
u8 hour; /* RTC + 0x11 */
u8 minute; /* RTC + 0x12 */
u8 second; /* RTC + 0x13 */
u8 month; /* RTC + 0x14 */
u8 wday_mday; /* RTC + 0x15 */
u16 year; /* RTC + 0x16 */
u8 int_alm; /* RTC + 0x18 */
u8 int_sw; /* RTC + 0x19 */
u8 alm_status; /* RTC + 0x1a */
u8 sw_minute; /* RTC + 0x1b */
u8 bus_error_1; /* RTC + 0x1c */
u8 int_day; /* RTC + 0x1d */
u8 int_min; /* RTC + 0x1e */
u8 int_sec; /* RTC + 0x1f */
/*
* target_time:
* intended to be used for hibernation but hibernation
* does not work on silicon rev 1.5 so use it for non-volatile
* storage of offset between the actual_time register and linux
* time
*/
u32 target_time; /* RTC + 0x20 */
/*
* actual_time:
* readonly time since VBAT_RTC was last connected
*/
u32 actual_time; /* RTC + 0x24 */
u32 keep_alive; /* RTC + 0x28 */
};
struct mpc5121_rtc_data {
unsigned irq;
unsigned irq_periodic;
struct mpc5121_rtc_regs __iomem *regs;
struct rtc_device *rtc;
struct rtc_wkalrm wkalarm;
};
/*
* Update second/minute/hour registers.
*
* This is just so alarm will work.
*/
static void mpc5121_rtc_update_smh(struct mpc5121_rtc_regs __iomem *regs,
struct rtc_time *tm)
{
out_8(®s->second_set, tm->tm_sec);
out_8(®s->minute_set, tm->tm_min);
out_8(®s->hour_set, tm->tm_hour);
/* set time sequence */
out_8(®s->set_time, 0x1);
out_8(®s->set_time, 0x3);
out_8(®s->set_time, 0x1);
out_8(®s->set_time, 0x0);
}
static int mpc5121_rtc_read_time(struct device *dev, struct rtc_time *tm)
{
struct mpc5121_rtc_data *rtc = dev_get_drvdata(dev);
struct mpc5121_rtc_regs __iomem *regs = rtc->regs;
unsigned long now;
/*
* linux time is actual_time plus the offset saved in target_time
*/
now = in_be32(®s->actual_time) + in_be32(®s->target_time);
rtc_time_to_tm(now, tm);
/*
* update second minute hour registers
* so alarms will work
*/
mpc5121_rtc_update_smh(regs, tm);
return rtc_valid_tm(tm);
}
static int mpc5121_rtc_set_time(struct device *dev, struct rtc_time *tm)
{
struct mpc5121_rtc_data *rtc = dev_get_drvdata(dev);
struct mpc5121_rtc_regs __iomem *regs = rtc->regs;
int ret;
unsigned long now;
/*
* The actual_time register is read only so we write the offset
* between it and linux time to the target_time register.
*/
ret = rtc_tm_to_time(tm, &now);
if (ret == 0)
out_be32(®s->target_time, now - in_be32(®s->actual_time));
/*
* update second minute hour registers
* so alarms will work
*/
mpc5121_rtc_update_smh(regs, tm);
return 0;
}
static int mpc5121_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alarm)
{
struct mpc5121_rtc_data *rtc = dev_get_drvdata(dev);
struct mpc5121_rtc_regs __iomem *regs = rtc->regs;
*alarm = rtc->wkalarm;
alarm->pending = in_8(®s->alm_status);
return 0;
}
static int mpc5121_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alarm)
{
struct mpc5121_rtc_data *rtc = dev_get_drvdata(dev);
struct mpc5121_rtc_regs __iomem *regs = rtc->regs;
/*
* the alarm has no seconds so deal with it
*/
if (alarm->time.tm_sec) {
alarm->time.tm_sec = 0;
alarm->time.tm_min++;
if (alarm->time.tm_min >= 60) {
alarm->time.tm_min = 0;
alarm->time.tm_hour++;
if (alarm->time.tm_hour >= 24)
alarm->time.tm_hour = 0;
}
}
alarm->time.tm_mday = -1;
alarm->time.tm_mon = -1;
alarm->time.tm_year = -1;
out_8(®s->alm_min_set, alarm->time.tm_min);
out_8(®s->alm_hour_set, alarm->time.tm_hour);
out_8(®s->alm_enable, alarm->enabled);
rtc->wkalarm = *alarm;
return 0;
}
static irqreturn_t mpc5121_rtc_handler(int irq, void *dev)
{
struct mpc5121_rtc_data *rtc = dev_get_drvdata((struct device *)dev);
struct mpc5121_rtc_regs __iomem *regs = rtc->regs;
if (in_8(®s->int_alm)) {
/* acknowledge and clear status */
out_8(®s->int_alm, 1);
out_8(®s->alm_status, 1);
rtc_update_irq(rtc->rtc, 1, RTC_IRQF | RTC_AF);
return IRQ_HANDLED;
}
return IRQ_NONE;
}
static irqreturn_t mpc5121_rtc_handler_upd(int irq, void *dev)
{
struct mpc5121_rtc_data *rtc = dev_get_drvdata((struct device *)dev);
struct mpc5121_rtc_regs __iomem *regs = rtc->regs;
if (in_8(®s->int_sec) && (in_8(®s->int_enable) & 0x1)) {
/* acknowledge */
out_8(®s->int_sec, 1);
rtc_update_irq(rtc->rtc, 1, RTC_IRQF | RTC_UF);
return IRQ_HANDLED;
}
return IRQ_NONE;
}
static int mpc5121_rtc_alarm_irq_enable(struct device *dev,
unsigned int enabled)
{
struct mpc5121_rtc_data *rtc = dev_get_drvdata(dev);
struct mpc5121_rtc_regs __iomem *regs = rtc->regs;
int val;
if (enabled)
val = 1;
else
val = 0;
out_8(®s->alm_enable, val);
rtc->wkalarm.enabled = val;
return 0;
}
static const struct rtc_class_ops mpc5121_rtc_ops = {
.read_time = mpc5121_rtc_read_time,
.set_time = mpc5121_rtc_set_time,
.read_alarm = mpc5121_rtc_read_alarm,
.set_alarm = mpc5121_rtc_set_alarm,
.alarm_irq_enable = mpc5121_rtc_alarm_irq_enable,
};
static int __devinit mpc5121_rtc_probe(struct platform_device *op)
{
struct mpc5121_rtc_data *rtc;
int err = 0;
u32 ka;
rtc = kzalloc(sizeof(*rtc), GFP_KERNEL);
if (!rtc)
return -ENOMEM;
rtc->regs = of_iomap(op->dev.of_node, 0);
if (!rtc->regs) {
dev_err(&op->dev, "%s: couldn't map io space\n", __func__);
err = -ENOSYS;
goto out_free;
}
device_init_wakeup(&op->dev, 1);
dev_set_drvdata(&op->dev, rtc);
rtc->irq = irq_of_parse_and_map(op->dev.of_node, 1);
err = request_irq(rtc->irq, mpc5121_rtc_handler, IRQF_DISABLED,
"mpc5121-rtc", &op->dev);
if (err) {
dev_err(&op->dev, "%s: could not request irq: %i\n",
__func__, rtc->irq);
goto out_dispose;
}
rtc->irq_periodic = irq_of_parse_and_map(op->dev.of_node, 0);
err = request_irq(rtc->irq_periodic, mpc5121_rtc_handler_upd,
IRQF_DISABLED, "mpc5121-rtc_upd", &op->dev);
if (err) {
dev_err(&op->dev, "%s: could not request irq: %i\n",
__func__, rtc->irq_periodic);
goto out_dispose2;
}
ka = in_be32(&rtc->regs->keep_alive);
if (ka & 0x02) {
dev_warn(&op->dev,
"mpc5121-rtc: Battery or oscillator failure!\n");
out_be32(&rtc->regs->keep_alive, ka);
}
rtc->rtc = rtc_device_register("mpc5121-rtc", &op->dev,
&mpc5121_rtc_ops, THIS_MODULE);
if (IS_ERR(rtc->rtc)) {
err = PTR_ERR(rtc->rtc);
goto out_free_irq;
}
return 0;
out_free_irq:
free_irq(rtc->irq_periodic, &op->dev);
out_dispose2:
irq_dispose_mapping(rtc->irq_periodic);
free_irq(rtc->irq, &op->dev);
out_dispose:
irq_dispose_mapping(rtc->irq);
iounmap(rtc->regs);
out_free:
kfree(rtc);
return err;
}
static int __devexit mpc5121_rtc_remove(struct platform_device *op)
{
struct mpc5121_rtc_data *rtc = dev_get_drvdata(&op->dev);
struct mpc5121_rtc_regs __iomem *regs = rtc->regs;
/* disable interrupt, so there are no nasty surprises */
out_8(®s->alm_enable, 0);
out_8(®s->int_enable, in_8(®s->int_enable) & ~0x1);
rtc_device_unregister(rtc->rtc);
iounmap(rtc->regs);
free_irq(rtc->irq, &op->dev);
free_irq(rtc->irq_periodic, &op->dev);
irq_dispose_mapping(rtc->irq);
irq_dispose_mapping(rtc->irq_periodic);
dev_set_drvdata(&op->dev, NULL);
kfree(rtc);
return 0;
}
static struct of_device_id mpc5121_rtc_match[] __devinitdata = {
{ .compatible = "fsl,mpc5121-rtc", },
{},
};
static struct platform_driver mpc5121_rtc_driver = {
.driver = {
.name = "mpc5121-rtc",
.owner = THIS_MODULE,
.of_match_table = mpc5121_rtc_match,
},
.probe = mpc5121_rtc_probe,
.remove = __devexit_p(mpc5121_rtc_remove),
};
static int __init mpc5121_rtc_init(void)
{
return platform_driver_register(&mpc5121_rtc_driver);
}
module_init(mpc5121_rtc_init);
static void __exit mpc5121_rtc_exit(void)
{
platform_driver_unregister(&mpc5121_rtc_driver);
}
module_exit(mpc5121_rtc_exit);
MODULE_LICENSE("GPL");
MODULE_AUTHOR("John Rigby <jcrigby@gmail.com>");