diff options
Diffstat (limited to 'drivers/rtc/rtc-mc13xxx.c')
| -rw-r--r-- | drivers/rtc/rtc-mc13xxx.c | 365 |
1 files changed, 365 insertions, 0 deletions
diff --git a/drivers/rtc/rtc-mc13xxx.c b/drivers/rtc/rtc-mc13xxx.c new file mode 100644 index 000000000..d6802e619 --- /dev/null +++ b/drivers/rtc/rtc-mc13xxx.c @@ -0,0 +1,365 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Real Time Clock driver for Freescale MC13XXX PMIC + * + * (C) 2009 Sascha Hauer, Pengutronix + * (C) 2009 Uwe Kleine-Koenig, Pengutronix + */ + +#include <linux/mfd/mc13xxx.h> +#include <linux/platform_device.h> +#include <linux/kernel.h> +#include <linux/module.h> +#include <linux/mod_devicetable.h> +#include <linux/slab.h> +#include <linux/rtc.h> + +#define DRIVER_NAME "mc13xxx-rtc" + +#define MC13XXX_RTCTOD 20 +#define MC13XXX_RTCTODA 21 +#define MC13XXX_RTCDAY 22 +#define MC13XXX_RTCDAYA 23 + +#define SEC_PER_DAY (24 * 60 * 60) + +struct mc13xxx_rtc { + struct rtc_device *rtc; + struct mc13xxx *mc13xxx; + int valid; +}; + +static int mc13xxx_rtc_irq_enable_unlocked(struct device *dev, + unsigned int enabled, int irq) +{ + struct mc13xxx_rtc *priv = dev_get_drvdata(dev); + int (*func)(struct mc13xxx *mc13xxx, int irq); + + if (!priv->valid) + return -ENODATA; + + func = enabled ? mc13xxx_irq_unmask : mc13xxx_irq_mask; + return func(priv->mc13xxx, irq); +} + +static int mc13xxx_rtc_alarm_irq_enable(struct device *dev, + unsigned int enabled) +{ + struct mc13xxx_rtc *priv = dev_get_drvdata(dev); + int ret; + + mc13xxx_lock(priv->mc13xxx); + + ret = mc13xxx_rtc_irq_enable_unlocked(dev, enabled, MC13XXX_IRQ_TODA); + + mc13xxx_unlock(priv->mc13xxx); + + return ret; +} + +static int mc13xxx_rtc_read_time(struct device *dev, struct rtc_time *tm) +{ + struct mc13xxx_rtc *priv = dev_get_drvdata(dev); + unsigned int seconds, days1, days2; + + if (!priv->valid) + return -ENODATA; + + do { + int ret; + + ret = mc13xxx_reg_read(priv->mc13xxx, MC13XXX_RTCDAY, &days1); + if (ret) + return ret; + + ret = mc13xxx_reg_read(priv->mc13xxx, MC13XXX_RTCTOD, &seconds); + if (ret) + return ret; + + ret = mc13xxx_reg_read(priv->mc13xxx, MC13XXX_RTCDAY, &days2); + if (ret) + return ret; + } while (days1 != days2); + + rtc_time64_to_tm((time64_t)days1 * SEC_PER_DAY + seconds, tm); + + return 0; +} + +static int mc13xxx_rtc_set_time(struct device *dev, struct rtc_time *tm) +{ + struct mc13xxx_rtc *priv = dev_get_drvdata(dev); + unsigned int seconds, days; + unsigned int alarmseconds; + int ret; + + days = div_s64_rem(rtc_tm_to_time64(tm), SEC_PER_DAY, &seconds); + + mc13xxx_lock(priv->mc13xxx); + + /* + * temporarily invalidate alarm to prevent triggering it when the day is + * already updated while the time isn't yet. + */ + ret = mc13xxx_reg_read(priv->mc13xxx, MC13XXX_RTCTODA, &alarmseconds); + if (unlikely(ret)) + goto out; + + if (alarmseconds < SEC_PER_DAY) { + ret = mc13xxx_reg_write(priv->mc13xxx, + MC13XXX_RTCTODA, 0x1ffff); + if (unlikely(ret)) + goto out; + } + + /* + * write seconds=0 to prevent a day switch between writing days + * and seconds below + */ + ret = mc13xxx_reg_write(priv->mc13xxx, MC13XXX_RTCTOD, 0); + if (unlikely(ret)) + goto out; + + ret = mc13xxx_reg_write(priv->mc13xxx, MC13XXX_RTCDAY, days); + if (unlikely(ret)) + goto out; + + ret = mc13xxx_reg_write(priv->mc13xxx, MC13XXX_RTCTOD, seconds); + if (unlikely(ret)) + goto out; + + /* restore alarm */ + if (alarmseconds < SEC_PER_DAY) { + ret = mc13xxx_reg_write(priv->mc13xxx, + MC13XXX_RTCTODA, alarmseconds); + if (unlikely(ret)) + goto out; + } + + if (!priv->valid) { + ret = mc13xxx_irq_ack(priv->mc13xxx, MC13XXX_IRQ_RTCRST); + if (unlikely(ret)) + goto out; + + ret = mc13xxx_irq_unmask(priv->mc13xxx, MC13XXX_IRQ_RTCRST); + } + +out: + priv->valid = !ret; + + mc13xxx_unlock(priv->mc13xxx); + + return ret; +} + +static int mc13xxx_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alarm) +{ + struct mc13xxx_rtc *priv = dev_get_drvdata(dev); + unsigned int seconds, days; + time64_t s1970; + int enabled, pending; + int ret; + + mc13xxx_lock(priv->mc13xxx); + + ret = mc13xxx_reg_read(priv->mc13xxx, MC13XXX_RTCTODA, &seconds); + if (unlikely(ret)) + goto out; + if (seconds >= SEC_PER_DAY) { + ret = -ENODATA; + goto out; + } + + ret = mc13xxx_reg_read(priv->mc13xxx, MC13XXX_RTCDAY, &days); + if (unlikely(ret)) + goto out; + + ret = mc13xxx_irq_status(priv->mc13xxx, MC13XXX_IRQ_TODA, + &enabled, &pending); + +out: + mc13xxx_unlock(priv->mc13xxx); + + if (ret) + return ret; + + alarm->enabled = enabled; + alarm->pending = pending; + + s1970 = (time64_t)days * SEC_PER_DAY + seconds; + + rtc_time64_to_tm(s1970, &alarm->time); + dev_dbg(dev, "%s: %lld\n", __func__, (long long)s1970); + + return 0; +} + +static int mc13xxx_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alarm) +{ + struct mc13xxx_rtc *priv = dev_get_drvdata(dev); + time64_t s1970; + u32 seconds, days; + int ret; + + mc13xxx_lock(priv->mc13xxx); + + /* disable alarm to prevent false triggering */ + ret = mc13xxx_reg_write(priv->mc13xxx, MC13XXX_RTCTODA, 0x1ffff); + if (unlikely(ret)) + goto out; + + ret = mc13xxx_irq_ack(priv->mc13xxx, MC13XXX_IRQ_TODA); + if (unlikely(ret)) + goto out; + + s1970 = rtc_tm_to_time64(&alarm->time); + + dev_dbg(dev, "%s: %s %lld\n", __func__, alarm->enabled ? "on" : "off", + (long long)s1970); + + ret = mc13xxx_rtc_irq_enable_unlocked(dev, alarm->enabled, + MC13XXX_IRQ_TODA); + if (unlikely(ret)) + goto out; + + days = div_s64_rem(s1970, SEC_PER_DAY, &seconds); + + ret = mc13xxx_reg_write(priv->mc13xxx, MC13XXX_RTCDAYA, days); + if (unlikely(ret)) + goto out; + + ret = mc13xxx_reg_write(priv->mc13xxx, MC13XXX_RTCTODA, seconds); + +out: + mc13xxx_unlock(priv->mc13xxx); + + return ret; +} + +static irqreturn_t mc13xxx_rtc_alarm_handler(int irq, void *dev) +{ + struct mc13xxx_rtc *priv = dev; + struct mc13xxx *mc13xxx = priv->mc13xxx; + + rtc_update_irq(priv->rtc, 1, RTC_IRQF | RTC_AF); + + mc13xxx_irq_ack(mc13xxx, irq); + + return IRQ_HANDLED; +} + +static const struct rtc_class_ops mc13xxx_rtc_ops = { + .read_time = mc13xxx_rtc_read_time, + .set_time = mc13xxx_rtc_set_time, + .read_alarm = mc13xxx_rtc_read_alarm, + .set_alarm = mc13xxx_rtc_set_alarm, + .alarm_irq_enable = mc13xxx_rtc_alarm_irq_enable, +}; + +static irqreturn_t mc13xxx_rtc_reset_handler(int irq, void *dev) +{ + struct mc13xxx_rtc *priv = dev; + struct mc13xxx *mc13xxx = priv->mc13xxx; + + priv->valid = 0; + + mc13xxx_irq_mask(mc13xxx, irq); + + return IRQ_HANDLED; +} + +static int __init mc13xxx_rtc_probe(struct platform_device *pdev) +{ + int ret; + struct mc13xxx_rtc *priv; + struct mc13xxx *mc13xxx; + + priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL); + if (!priv) + return -ENOMEM; + + mc13xxx = dev_get_drvdata(pdev->dev.parent); + priv->mc13xxx = mc13xxx; + priv->valid = 1; + + priv->rtc = devm_rtc_allocate_device(&pdev->dev); + if (IS_ERR(priv->rtc)) + return PTR_ERR(priv->rtc); + platform_set_drvdata(pdev, priv); + + priv->rtc->ops = &mc13xxx_rtc_ops; + /* 15bit days + hours, minutes, seconds */ + priv->rtc->range_max = (timeu64_t)(1 << 15) * SEC_PER_DAY - 1; + + mc13xxx_lock(mc13xxx); + + mc13xxx_irq_ack(mc13xxx, MC13XXX_IRQ_RTCRST); + + ret = mc13xxx_irq_request(mc13xxx, MC13XXX_IRQ_RTCRST, + mc13xxx_rtc_reset_handler, DRIVER_NAME, priv); + if (ret) + goto err_irq_request; + + ret = mc13xxx_irq_request_nounmask(mc13xxx, MC13XXX_IRQ_TODA, + mc13xxx_rtc_alarm_handler, DRIVER_NAME, priv); + if (ret) + goto err_irq_request; + + mc13xxx_unlock(mc13xxx); + + ret = rtc_register_device(priv->rtc); + if (ret) { + mc13xxx_lock(mc13xxx); + goto err_irq_request; + } + + return 0; + +err_irq_request: + mc13xxx_irq_free(mc13xxx, MC13XXX_IRQ_TODA, priv); + mc13xxx_irq_free(mc13xxx, MC13XXX_IRQ_RTCRST, priv); + + mc13xxx_unlock(mc13xxx); + + return ret; +} + +static int mc13xxx_rtc_remove(struct platform_device *pdev) +{ + struct mc13xxx_rtc *priv = platform_get_drvdata(pdev); + + mc13xxx_lock(priv->mc13xxx); + + mc13xxx_irq_free(priv->mc13xxx, MC13XXX_IRQ_TODA, priv); + mc13xxx_irq_free(priv->mc13xxx, MC13XXX_IRQ_RTCRST, priv); + + mc13xxx_unlock(priv->mc13xxx); + + return 0; +} + +static const struct platform_device_id mc13xxx_rtc_idtable[] = { + { + .name = "mc13783-rtc", + }, { + .name = "mc13892-rtc", + }, { + .name = "mc34708-rtc", + }, + { /* sentinel */ } +}; +MODULE_DEVICE_TABLE(platform, mc13xxx_rtc_idtable); + +static struct platform_driver mc13xxx_rtc_driver = { + .id_table = mc13xxx_rtc_idtable, + .remove = mc13xxx_rtc_remove, + .driver = { + .name = DRIVER_NAME, + }, +}; + +module_platform_driver_probe(mc13xxx_rtc_driver, &mc13xxx_rtc_probe); + +MODULE_AUTHOR("Sascha Hauer <s.hauer@pengutronix.de>"); +MODULE_DESCRIPTION("RTC driver for Freescale MC13XXX PMIC"); +MODULE_LICENSE("GPL v2"); |