/*
* Copyright (C) 2017 Spreadtrum Communications Inc.
*
* SPDX-License-Identifier: GPL-2.0
*/
#include <linux/bitops.h>
#include <linux/delay.h>
#include <linux/err.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/platform_device.h>
#include <linux/regmap.h>
#include <linux/rtc.h>
#define SPRD_RTC_SEC_CNT_VALUE 0x0
#define SPRD_RTC_MIN_CNT_VALUE 0x4
#define SPRD_RTC_HOUR_CNT_VALUE 0x8
#define SPRD_RTC_DAY_CNT_VALUE 0xc
#define SPRD_RTC_SEC_CNT_UPD 0x10
#define SPRD_RTC_MIN_CNT_UPD 0x14
#define SPRD_RTC_HOUR_CNT_UPD 0x18
#define SPRD_RTC_DAY_CNT_UPD 0x1c
#define SPRD_RTC_SEC_ALM_UPD 0x20
#define SPRD_RTC_MIN_ALM_UPD 0x24
#define SPRD_RTC_HOUR_ALM_UPD 0x28
#define SPRD_RTC_DAY_ALM_UPD 0x2c
#define SPRD_RTC_INT_EN 0x30
#define SPRD_RTC_INT_RAW_STS 0x34
#define SPRD_RTC_INT_CLR 0x38
#define SPRD_RTC_INT_MASK_STS 0x3C
#define SPRD_RTC_SEC_ALM_VALUE 0x40
#define SPRD_RTC_MIN_ALM_VALUE 0x44
#define SPRD_RTC_HOUR_ALM_VALUE 0x48
#define SPRD_RTC_DAY_ALM_VALUE 0x4c
#define SPRD_RTC_SPG_VALUE 0x50
#define SPRD_RTC_SPG_UPD 0x54
#define SPRD_RTC_PWR_CTRL 0x58
#define SPRD_RTC_PWR_STS 0x5c
#define SPRD_RTC_SEC_AUXALM_UPD 0x60
#define SPRD_RTC_MIN_AUXALM_UPD 0x64
#define SPRD_RTC_HOUR_AUXALM_UPD 0x68
#define SPRD_RTC_DAY_AUXALM_UPD 0x6c
/* BIT & MASK definition for SPRD_RTC_INT_* registers */
#define SPRD_RTC_SEC_EN BIT(0)
#define SPRD_RTC_MIN_EN BIT(1)
#define SPRD_RTC_HOUR_EN BIT(2)
#define SPRD_RTC_DAY_EN BIT(3)
#define SPRD_RTC_ALARM_EN BIT(4)
#define SPRD_RTC_HRS_FORMAT_EN BIT(5)
#define SPRD_RTC_AUXALM_EN BIT(6)
#define SPRD_RTC_SPG_UPD_EN BIT(7)
#define SPRD_RTC_SEC_UPD_EN BIT(8)
#define SPRD_RTC_MIN_UPD_EN BIT(9)
#define SPRD_RTC_HOUR_UPD_EN BIT(10)
#define SPRD_RTC_DAY_UPD_EN BIT(11)
#define SPRD_RTC_ALMSEC_UPD_EN BIT(12)
#define SPRD_RTC_ALMMIN_UPD_EN BIT(13)
#define SPRD_RTC_ALMHOUR_UPD_EN BIT(14)
#define SPRD_RTC_ALMDAY_UPD_EN BIT(15)
#define SPRD_RTC_INT_MASK GENMASK(15, 0)
#define SPRD_RTC_TIME_INT_MASK \
(SPRD_RTC_SEC_UPD_EN | SPRD_RTC_MIN_UPD_EN | \
SPRD_RTC_HOUR_UPD_EN | SPRD_RTC_DAY_UPD_EN)
#define SPRD_RTC_ALMTIME_INT_MASK \
(SPRD_RTC_ALMSEC_UPD_EN | SPRD_RTC_ALMMIN_UPD_EN | \
SPRD_RTC_ALMHOUR_UPD_EN | SPRD_RTC_ALMDAY_UPD_EN)
#define SPRD_RTC_ALM_INT_MASK \
(SPRD_RTC_SEC_EN | SPRD_RTC_MIN_EN | \
SPRD_RTC_HOUR_EN | SPRD_RTC_DAY_EN | \
SPRD_RTC_ALARM_EN | SPRD_RTC_AUXALM_EN)
/* second/minute/hour/day values mask definition */
#define SPRD_RTC_SEC_MASK GENMASK(5, 0)
#define SPRD_RTC_MIN_MASK GENMASK(5, 0)
#define SPRD_RTC_HOUR_MASK GENMASK(4, 0)
#define SPRD_RTC_DAY_MASK GENMASK(15, 0)
/* alarm lock definition for SPRD_RTC_SPG_UPD register */
#define SPRD_RTC_ALMLOCK_MASK GENMASK(7, 0)
#define SPRD_RTC_ALM_UNLOCK 0xa5
#define SPRD_RTC_ALM_LOCK (~SPRD_RTC_ALM_UNLOCK & \
SPRD_RTC_ALMLOCK_MASK)
/* SPG values definition for SPRD_RTC_SPG_UPD register */
#define SPRD_RTC_POWEROFF_ALM_FLAG BIT(8)
/* power control/status definition */
#define SPRD_RTC_POWER_RESET_VALUE 0x96
#define SPRD_RTC_POWER_STS_CLEAR GENMASK(7, 0)
#define SPRD_RTC_POWER_STS_SHIFT 8
#define SPRD_RTC_POWER_STS_VALID \
(~SPRD_RTC_POWER_RESET_VALUE << SPRD_RTC_POWER_STS_SHIFT)
/* timeout of synchronizing time and alarm registers (us) */
#define SPRD_RTC_POLL_TIMEOUT 200000
#define SPRD_RTC_POLL_DELAY_US 20000
struct sprd_rtc {
struct rtc_device *rtc;
struct regmap *regmap;
struct device *dev;
u32 base;
int irq;
bool valid;
};
/*
* The Spreadtrum RTC controller has 3 groups registers, including time, normal
* alarm and auxiliary alarm. The time group registers are used to set RTC time,
* the normal alarm registers are used to set normal alarm, and the auxiliary
* alarm registers are used to set auxiliary alarm. Both alarm event and
* auxiliary alarm event can wake up system from deep sleep, but only alarm
* event can power up system from power down status.
*/
enum sprd_rtc_reg_types {
SPRD_RTC_TIME,
SPRD_RTC_ALARM,
SPRD_RTC_AUX_ALARM,
};
static int sprd_rtc_clear_alarm_ints(struct sprd_rtc *rtc)
{
return regmap_write(rtc->regmap, rtc->base + SPRD_RTC_INT_CLR,
SPRD_RTC_ALM_INT_MASK);
}
static int sprd_rtc_disable_ints(struct sprd_rtc *rtc)
{
int ret;
ret = regmap_update_bits(rtc->regmap, rtc->base + SPRD_RTC_INT_EN,
SPRD_RTC_INT_MASK, 0);
if (ret)
return ret;
return regmap_write(rtc->regmap, rtc->base + SPRD_RTC_INT_CLR,
SPRD_RTC_INT_MASK);
}
static int sprd_rtc_lock_alarm(struct sprd_rtc *rtc, bool lock)
{
int ret;
u32 val;
ret = regmap_read(rtc->regmap, rtc->base + SPRD_RTC_SPG_VALUE, &val);
if (ret)
return ret;
val &= ~(SPRD_RTC_ALMLOCK_MASK | SPRD_RTC_POWEROFF_ALM_FLAG);
if (lock)
val |= SPRD_RTC_ALM_LOCK;
else
val |= SPRD_RTC_ALM_UNLOCK | SPRD_RTC_POWEROFF_ALM_FLAG;
ret = regmap_write(rtc->regmap, rtc->base + SPRD_RTC_SPG_UPD, val);
if (ret)
return ret;
/* wait until the SPG value is updated successfully */
ret = regmap_read_poll_timeout(rtc->regmap,
rtc->base + SPRD_RTC_INT_RAW_STS, val,
(val & SPRD_RTC_SPG_UPD_EN),
SPRD_RTC_POLL_DELAY_US,
SPRD_RTC_POLL_TIMEOUT);
if (ret) {
dev_err(rtc->dev, "failed to update SPG value:%d\n", ret);
return ret;
}
return 0;
}
static int sprd_rtc_get_secs(struct sprd_rtc *rtc, enum sprd_rtc_reg_types type,
time64_t *secs)
{
u32 sec_reg, min_reg, hour_reg, day_reg;
u32 val, sec, min, hour, day;
int ret;
switch (type) {
case SPRD_RTC_TIME:
sec_reg = SPRD_RTC_SEC_CNT_VALUE;
min_reg = SPRD_RTC_MIN_CNT_VALUE;
hour_reg = SPRD_RTC_HOUR_CNT_VALUE;
day_reg = SPRD_RTC_DAY_CNT_VALUE;
break;
case SPRD_RTC_ALARM:
sec_reg = SPRD_RTC_SEC_ALM_VALUE;
min_reg = SPRD_RTC_MIN_ALM_VALUE;
hour_reg = SPRD_RTC_HOUR_ALM_VALUE;
day_reg = SPRD_RTC_DAY_ALM_VALUE;
break;
case SPRD_RTC_AUX_ALARM:
sec_reg = SPRD_RTC_SEC_AUXALM_UPD;
min_reg = SPRD_RTC_MIN_AUXALM_UPD;
hour_reg = SPRD_RTC_HOUR_AUXALM_UPD;
day_reg = SPRD_RTC_DAY_AUXALM_UPD;
break;
default:
return -EINVAL;
}
ret = regmap_read(rtc->regmap, rtc->base + sec_reg, &val);
if (ret)
return ret;
sec = val & SPRD_RTC_SEC_MASK;
ret = regmap_read(rtc->regmap, rtc->base + min_reg, &val);
if (ret)
return ret;
min = val & SPRD_RTC_MIN_MASK;
ret = regmap_read(rtc->regmap, rtc->base + hour_reg, &val);
if (ret)
return ret;
hour = val & SPRD_RTC_HOUR_MASK;
ret = regmap_read(rtc->regmap, rtc->base + day_reg, &val);
if (ret)
return ret;
day = val & SPRD_RTC_DAY_MASK;
*secs = (((time64_t)(day * 24) + hour) * 60 + min) * 60 + sec;
return 0;
}
static int sprd_rtc_set_secs(struct sprd_rtc *rtc, enum sprd_rtc_reg_types type,
time64_t secs)
{
u32 sec_reg, min_reg, hour_reg, day_reg, sts_mask;
u32 sec, min, hour, day, val;
int ret, rem;
/* convert seconds to RTC time format */
day = div_s64_rem(secs, 86400, &rem);
hour = rem / 3600;
rem -= hour * 3600;
min = rem / 60;
sec = rem - min * 60;
switch (type) {
case SPRD_RTC_TIME:
sec_reg = SPRD_RTC_SEC_CNT_UPD;
min_reg = SPRD_RTC_MIN_CNT_UPD;
hour_reg = SPRD_RTC_HOUR_CNT_UPD;
day_reg = SPRD_RTC_DAY_CNT_UPD;
sts_mask = SPRD_RTC_TIME_INT_MASK;
break;
case SPRD_RTC_ALARM:
sec_reg = SPRD_RTC_SEC_ALM_UPD;
min_reg = SPRD_RTC_MIN_ALM_UPD;
hour_reg = SPRD_RTC_HOUR_ALM_UPD;
day_reg = SPRD_RTC_DAY_ALM_UPD;
sts_mask = SPRD_RTC_ALMTIME_INT_MASK;
break;
case SPRD_RTC_AUX_ALARM:
sec_reg = SPRD_RTC_SEC_AUXALM_UPD;
min_reg = SPRD_RTC_MIN_AUXALM_UPD;
hour_reg = SPRD_RTC_HOUR_AUXALM_UPD;
day_reg = SPRD_RTC_DAY_AUXALM_UPD;
sts_mask = 0;
break;
default:
return -EINVAL;
}
ret = regmap_write(rtc->regmap, rtc->base + sec_reg, sec);
if (ret)
return ret;
ret = regmap_write(rtc->regmap, rtc->base + min_reg, min);
if (ret)
return ret;
ret = regmap_write(rtc->regmap, rtc->base + hour_reg, hour);
if (ret)
return ret;
ret = regmap_write(rtc->regmap, rtc->base + day_reg, day);
if (ret)
return ret;
if (type == SPRD_RTC_AUX_ALARM)
return 0;
/*
* Since the time and normal alarm registers are put in always-power-on
* region supplied by VDDRTC, then these registers changing time will
* be very long, about 125ms. Thus here we should wait until all
* values are updated successfully.
*/
ret = regmap_read_poll_timeout(rtc->regmap,
rtc->base + SPRD_RTC_INT_RAW_STS, val,
((val & sts_mask) == sts_mask),
SPRD_RTC_POLL_DELAY_US,
SPRD_RTC_POLL_TIMEOUT);
if (ret < 0) {
dev_err(rtc->dev, "set time/alarm values timeout\n");
return ret;
}
return regmap_write(rtc->regmap, rtc->base + SPRD_RTC_INT_CLR,
sts_mask);
}
static int sprd_rtc_read_aux_alarm(struct device *dev, struct rtc_wkalrm *alrm)
{
struct sprd_rtc *rtc = dev_get_drvdata(dev);
time64_t secs;
u32 val;
int ret;
ret = sprd_rtc_get_secs(rtc, SPRD_RTC_AUX_ALARM, &secs);
if (ret)
return ret;
rtc_time64_to_tm(secs, &alrm->time);
ret = regmap_read(rtc->regmap, rtc->base + SPRD_RTC_INT_EN, &val);
if (ret)
return ret;
alrm->enabled = !!(val & SPRD_RTC_AUXALM_EN);
ret = regmap_read(rtc->regmap, rtc->base + SPRD_RTC_INT_RAW_STS, &val);
if (ret)
return ret;
alrm->pending = !!(val & SPRD_RTC_AUXALM_EN);
return 0;
}
static int sprd_rtc_set_aux_alarm(struct device *dev, struct rtc_wkalrm *alrm)
{
struct sprd_rtc *rtc = dev_get_drvdata(dev);
time64_t secs = rtc_tm_to_time64(&alrm->time);
int ret;
/* clear the auxiliary alarm interrupt status */
ret = regmap_write(rtc->regmap, rtc->base + SPRD_RTC_INT_CLR,
SPRD_RTC_AUXALM_EN);
if (ret)
return ret;
ret = sprd_rtc_set_secs(rtc, SPRD_RTC_AUX_ALARM, secs);
if (ret)
return ret;
if (alrm->enabled) {
ret = regmap_update_bits(rtc->regmap,
rtc->base + SPRD_RTC_INT_EN,
SPRD_RTC_AUXALM_EN,
SPRD_RTC_AUXALM_EN);
} else {
ret = regmap_update_bits(rtc->regmap,
rtc->base + SPRD_RTC_INT_EN,
SPRD_RTC_AUXALM_EN, 0);
}
return ret;
}
static int sprd_rtc_read_time(struct device *dev, struct rtc_time *tm)
{
struct sprd_rtc *rtc = dev_get_drvdata(dev);
time64_t secs;
int ret;
if (!rtc->valid) {
dev_warn(dev, "RTC values are invalid\n");
return -EINVAL;
}
ret = sprd_rtc_get_secs(rtc, SPRD_RTC_TIME, &secs);
if (ret)
return ret;
rtc_time64_to_tm(secs, tm);
return 0;
}
static int sprd_rtc_set_time(struct device *dev, struct rtc_time *tm)
{
struct sprd_rtc *rtc = dev_get_drvdata(dev);
time64_t secs = rtc_tm_to_time64(tm);
int ret;
ret = sprd_rtc_set_secs(rtc, SPRD_RTC_TIME, secs);
if (ret)
return ret;
if (!rtc->valid) {
/* Clear RTC power status firstly */
ret = regmap_write(rtc->regmap, rtc->base + SPRD_RTC_PWR_CTRL,
SPRD_RTC_POWER_STS_CLEAR);
if (ret)
return ret;
/*
* Set RTC power status to indicate now RTC has valid time
* values.
*/
ret = regmap_write(rtc->regmap, rtc->base + SPRD_RTC_PWR_CTRL,
SPRD_RTC_POWER_STS_VALID);
if (ret)
return ret;
rtc->valid = true;
}
return 0;
}
static int sprd_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alrm)
{
struct sprd_rtc *rtc = dev_get_drvdata(dev);
time64_t secs;
int ret;
u32 val;
/*
* If aie_timer is enabled, we should get the normal alarm time.
* Otherwise we should get auxiliary alarm time.
*/
if (rtc->rtc && rtc->rtc->aie_timer.enabled == 0)
return sprd_rtc_read_aux_alarm(dev, alrm);
ret = sprd_rtc_get_secs(rtc, SPRD_RTC_ALARM, &secs);
if (ret)
return ret;
rtc_time64_to_tm(secs, &alrm->time);
ret = regmap_read(rtc->regmap, rtc->base + SPRD_RTC_INT_EN, &val);
if (ret)
return ret;
alrm->enabled = !!(val & SPRD_RTC_ALARM_EN);
ret = regmap_read(rtc->regmap, rtc->base + SPRD_RTC_INT_RAW_STS, &val);
if (ret)
return ret;
alrm->pending = !!(val & SPRD_RTC_ALARM_EN);
return 0;
}
static int sprd_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm)
{
struct sprd_rtc *rtc = dev_get_drvdata(dev);
time64_t secs = rtc_tm_to_time64(&alrm->time);
struct rtc_time aie_time =
rtc_ktime_to_tm(rtc->rtc->aie_timer.node.expires);
int ret;
/*
* We have 2 groups alarms: normal alarm and auxiliary alarm. Since
* both normal alarm event and auxiliary alarm event can wake up system
* from deep sleep, but only alarm event can power up system from power
* down status. Moreover we do not need to poll about 125ms when
* updating auxiliary alarm registers. Thus we usually set auxiliary
* alarm when wake up system from deep sleep, and for other scenarios,
* we should set normal alarm with polling status.
*
* So here we check if the alarm time is set by aie_timer, if yes, we
* should set normal alarm, if not, we should set auxiliary alarm which
* means it is just a wake event.
*/
if (!rtc->rtc->aie_timer.enabled || rtc_tm_sub(&aie_time, &alrm->time))
return sprd_rtc_set_aux_alarm(dev, alrm);
/* clear the alarm interrupt status firstly */
ret = regmap_write(rtc->regmap, rtc->base + SPRD_RTC_INT_CLR,
SPRD_RTC_ALARM_EN);
if (ret)
return ret;
ret = sprd_rtc_set_secs(rtc, SPRD_RTC_ALARM, secs);
if (ret)
return ret;
if (alrm->enabled) {
ret = regmap_update_bits(rtc->regmap,
rtc->base + SPRD_RTC_INT_EN,
SPRD_RTC_ALARM_EN,
SPRD_RTC_ALARM_EN);
if (ret)
return ret;
/* unlock the alarm to enable the alarm function. */
ret = sprd_rtc_lock_alarm(rtc, false);
} else {
regmap_update_bits(rtc->regmap,
rtc->base + SPRD_RTC_INT_EN,
SPRD_RTC_ALARM_EN, 0);
/*
* Lock the alarm function in case fake alarm event will power
* up systems.
*/
ret = sprd_rtc_lock_alarm(rtc, true);
}
return ret;
}
static int sprd_rtc_alarm_irq_enable(struct device *dev, unsigned int enabled)
{
struct sprd_rtc *rtc = dev_get_drvdata(dev);
int ret;
if (enabled) {
ret = regmap_update_bits(rtc->regmap,
rtc->base + SPRD_RTC_INT_EN,
SPRD_RTC_ALARM_EN | SPRD_RTC_AUXALM_EN,
SPRD_RTC_ALARM_EN | SPRD_RTC_AUXALM_EN);
if (ret)
return ret;
ret = sprd_rtc_lock_alarm(rtc, false);
} else {
regmap_update_bits(rtc->regmap, rtc->base + SPRD_RTC_INT_EN,
SPRD_RTC_ALARM_EN | SPRD_RTC_AUXALM_EN, 0);
ret = sprd_rtc_lock_alarm(rtc, true);
}
return ret;
}
static const struct rtc_class_ops sprd_rtc_ops = {
.read_time = sprd_rtc_read_time,
.set_time = sprd_rtc_set_time,
.read_alarm = sprd_rtc_read_alarm,
.set_alarm = sprd_rtc_set_alarm,
.alarm_irq_enable = sprd_rtc_alarm_irq_enable,
};
static irqreturn_t sprd_rtc_handler(int irq, void *dev_id)
{
struct sprd_rtc *rtc = dev_id;
int ret;
ret = sprd_rtc_clear_alarm_ints(rtc);
if (ret)
return IRQ_RETVAL(ret);
rtc_update_irq(rtc->rtc, 1, RTC_AF | RTC_IRQF);
return IRQ_HANDLED;
}
static int sprd_rtc_check_power_down(struct sprd_rtc *rtc)
{
u32 val;
int ret;
ret = regmap_read(rtc->regmap, rtc->base + SPRD_RTC_PWR_STS, &val);
if (ret)
return ret;
/*
* If the RTC power status value is SPRD_RTC_POWER_RESET_VALUE, which
* means the RTC has been powered down, so the RTC time values are
* invalid.
*/
rtc->valid = val == SPRD_RTC_POWER_RESET_VALUE ? false : true;
return 0;
}
static int sprd_rtc_probe(struct platform_device *pdev)
{
struct device_node *node = pdev->dev.of_node;
struct sprd_rtc *rtc;
int ret;
rtc = devm_kzalloc(&pdev->dev, sizeof(*rtc), GFP_KERNEL);
if (!rtc)
return -ENOMEM;
rtc->regmap = dev_get_regmap(pdev->dev.parent, NULL);
if (!rtc->regmap)
return -ENODEV;
ret = of_property_read_u32(node, "reg", &rtc->base);
if (ret) {
dev_err(&pdev->dev, "failed to get RTC base address\n");
return ret;
}
rtc->irq = platform_get_irq(pdev, 0);
if (rtc->irq < 0) {
dev_err(&pdev->dev, "failed to get RTC irq number\n");
return rtc->irq;
}
rtc->rtc = devm_rtc_allocate_device(&pdev->dev);
if (IS_ERR(rtc->rtc))
return PTR_ERR(rtc->rtc);
rtc->dev = &pdev->dev;
platform_set_drvdata(pdev, rtc);
/* clear all RTC interrupts and disable all RTC interrupts */
ret = sprd_rtc_disable_ints(rtc);
if (ret) {
dev_err(&pdev->dev, "failed to disable RTC interrupts\n");
return ret;
}
/* check if RTC time values are valid */
ret = sprd_rtc_check_power_down(rtc);
if (ret) {
dev_err(&pdev->dev, "failed to check RTC time values\n");
return ret;
}
ret = devm_request_threaded_irq(&pdev->dev, rtc->irq, NULL,
sprd_rtc_handler,
IRQF_ONESHOT | IRQF_EARLY_RESUME,
pdev->name, rtc);
if (ret < 0) {
dev_err(&pdev->dev, "failed to request RTC irq\n");
return ret;
}
rtc->rtc->ops = &sprd_rtc_ops;
rtc->rtc->range_min = 0;
rtc->rtc->range_max = 5662310399LL;
ret = rtc_register_device(rtc->rtc);
if (ret) {
dev_err(&pdev->dev, "failed to register rtc device\n");
return ret;
}
device_init_wakeup(&pdev->dev, 1);
return 0;
}
static int sprd_rtc_remove(struct platform_device *pdev)
{
device_init_wakeup(&pdev->dev, 0);
return 0;
}
static const struct of_device_id sprd_rtc_of_match[] = {
{ .compatible = "sprd,sc2731-rtc", },
{ },
};
MODULE_DEVICE_TABLE(of, sprd_rtc_of_match);
static struct platform_driver sprd_rtc_driver = {
.driver = {
.name = "sprd-rtc",
.of_match_table = sprd_rtc_of_match,
},
.probe = sprd_rtc_probe,
.remove = sprd_rtc_remove,
};
module_platform_driver(sprd_rtc_driver);
MODULE_LICENSE("GPL v2");
MODULE_DESCRIPTION("Spreadtrum RTC Device Driver");
MODULE_AUTHOR("Baolin Wang <baolin.wang@spreadtrum.com>");
