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kernel-fxtec-pro1x/drivers/rtc/rtc-mpc5121.c
John Stultz 4a649903f9 rtc: Provide flag for rtc devices that don't support UIE 
Richard Weinberger noticed that on some RTC hardware that
doesn't support UIE mode, due to coarse granular alarms
(like 1minute resolution), the current virtualized RTC
support doesn't properly error out when UIE is enabled.

Instead the current code queues an alarm for the next second,
but it won't fire until up to a miniute later.

This patch provides a generic way to flag this sort of hardware
and fixes the issue on the mpc5121 where Richard noticed the
problem.

CC: stable@vger.kernel.org
Reported-by: Richard Weinberger <richard@nod.at>
Tested-by: Richard Weinberger <richard@nod.at>
Signed-off-by: John Stultz <john.stultz@linaro.org>
2012-03-15 18:23:10 -07:00

426 lines
10 KiB
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/*
* Real-time clock driver for MPC5121
*
* Copyright 2007, Domen Puncer <domen.puncer@telargo.com>
* Copyright 2008, Freescale Semiconductor, Inc. All rights reserved.
* Copyright 2011, Dmitry Eremin-Solenikov
*
* 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(&regs->second_set, tm->tm_sec);
out_8(&regs->minute_set, tm->tm_min);
out_8(&regs->hour_set, tm->tm_hour);
/* set time sequence */
out_8(&regs->set_time, 0x1);
out_8(&regs->set_time, 0x3);
out_8(&regs->set_time, 0x1);
out_8(&regs->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(&regs->actual_time) + in_be32(&regs->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(&regs->target_time, now - in_be32(&regs->actual_time));
/*
* update second minute hour registers
* so alarms will work
*/
mpc5121_rtc_update_smh(regs, tm);
return 0;
}
static int mpc5200_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;
int tmp;
tm->tm_sec = in_8(&regs->second);
tm->tm_min = in_8(&regs->minute);
/* 12 hour format? */
if (in_8(&regs->hour) & 0x20)
tm->tm_hour = (in_8(&regs->hour) >> 1) +
(in_8(&regs->hour) & 1 ? 12 : 0);
else
tm->tm_hour = in_8(&regs->hour);
tmp = in_8(&regs->wday_mday);
tm->tm_mday = tmp & 0x1f;
tm->tm_mon = in_8(&regs->month) - 1;
tm->tm_year = in_be16(&regs->year) - 1900;
tm->tm_wday = (tmp >> 5) % 7;
tm->tm_yday = rtc_year_days(tm->tm_mday, tm->tm_mon, tm->tm_year);
tm->tm_isdst = 0;
return 0;
}
static int mpc5200_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;
mpc5121_rtc_update_smh(regs, tm);
/* date */
out_8(&regs->month_set, tm->tm_mon + 1);
out_8(&regs->weekday_set, tm->tm_wday ? tm->tm_wday : 7);
out_8(&regs->date_set, tm->tm_mday);
out_be16(&regs->year_set, tm->tm_year + 1900);
/* set date sequence */
out_8(&regs->set_date, 0x1);
out_8(&regs->set_date, 0x3);
out_8(&regs->set_date, 0x1);
out_8(&regs->set_date, 0x0);
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(&regs->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(&regs->alm_min_set, alarm->time.tm_min);
out_8(&regs->alm_hour_set, alarm->time.tm_hour);
out_8(&regs->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(&regs->int_alm)) {
/* acknowledge and clear status */
out_8(&regs->int_alm, 1);
out_8(&regs->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(&regs->int_sec) && (in_8(&regs->int_enable) & 0x1)) {
/* acknowledge */
out_8(&regs->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(&regs->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 const struct rtc_class_ops mpc5200_rtc_ops = {
.read_time = mpc5200_rtc_read_time,
.set_time = mpc5200_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;
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;
}
if (of_device_is_compatible(op->dev.of_node, "fsl,mpc5121-rtc")) {
u32 ka;
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);
} else {
rtc->rtc = rtc_device_register("mpc5200-rtc", &op->dev,
&mpc5200_rtc_ops, THIS_MODULE);
}
rtc->rtc->uie_unsupported = 1;
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(&regs->alm_enable, 0);
out_8(&regs->int_enable, in_8(&regs->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", },
{ .compatible = "fsl,mpc5200-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),
};
module_platform_driver(mpc5121_rtc_driver);
MODULE_LICENSE("GPL");
MODULE_AUTHOR("John Rigby <jcrigby@gmail.com>");
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