diff options
Diffstat (limited to 'drivers/rtc/rtc-mt6397.c')
| -rw-r--r-- | drivers/rtc/rtc-mt6397.c | 395 |
1 files changed, 395 insertions, 0 deletions
diff --git a/drivers/rtc/rtc-mt6397.c b/drivers/rtc/rtc-mt6397.c new file mode 100644 index 000000000..eab230be5 --- /dev/null +++ b/drivers/rtc/rtc-mt6397.c @@ -0,0 +1,395 @@ +/* +* Copyright (c) 2014-2015 MediaTek Inc. +* Author: Tianping.Fang <tianping.fang@mediatek.com> +* +* 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. +* +* This program is distributed in the hope that it will be useful, +* but WITHOUT ANY WARRANTY; without even the implied warranty of +* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the +* GNU General Public License for more details. +*/ + +#include <linux/delay.h> +#include <linux/init.h> +#include <linux/module.h> +#include <linux/regmap.h> +#include <linux/rtc.h> +#include <linux/irqdomain.h> +#include <linux/platform_device.h> +#include <linux/of_address.h> +#include <linux/of_irq.h> +#include <linux/io.h> +#include <linux/mfd/mt6397/core.h> + +#define RTC_BBPU 0x0000 +#define RTC_BBPU_CBUSY BIT(6) + +#define RTC_WRTGR 0x003c + +#define RTC_IRQ_STA 0x0002 +#define RTC_IRQ_STA_AL BIT(0) +#define RTC_IRQ_STA_LP BIT(3) + +#define RTC_IRQ_EN 0x0004 +#define RTC_IRQ_EN_AL BIT(0) +#define RTC_IRQ_EN_ONESHOT BIT(2) +#define RTC_IRQ_EN_LP BIT(3) +#define RTC_IRQ_EN_ONESHOT_AL (RTC_IRQ_EN_ONESHOT | RTC_IRQ_EN_AL) + +#define RTC_AL_MASK 0x0008 +#define RTC_AL_MASK_DOW BIT(4) + +#define RTC_TC_SEC 0x000a +/* Min, Hour, Dom... register offset to RTC_TC_SEC */ +#define RTC_OFFSET_SEC 0 +#define RTC_OFFSET_MIN 1 +#define RTC_OFFSET_HOUR 2 +#define RTC_OFFSET_DOM 3 +#define RTC_OFFSET_DOW 4 +#define RTC_OFFSET_MTH 5 +#define RTC_OFFSET_YEAR 6 +#define RTC_OFFSET_COUNT 7 + +#define RTC_AL_SEC 0x0018 + +#define RTC_PDN2 0x002e +#define RTC_PDN2_PWRON_ALARM BIT(4) + +#define RTC_MIN_YEAR 1968 +#define RTC_BASE_YEAR 1900 +#define RTC_NUM_YEARS 128 +#define RTC_MIN_YEAR_OFFSET (RTC_MIN_YEAR - RTC_BASE_YEAR) + +struct mt6397_rtc { + struct device *dev; + struct rtc_device *rtc_dev; + struct mutex lock; + struct regmap *regmap; + int irq; + u32 addr_base; +}; + +static int mtk_rtc_write_trigger(struct mt6397_rtc *rtc) +{ + unsigned long timeout = jiffies + HZ; + int ret; + u32 data; + + ret = regmap_write(rtc->regmap, rtc->addr_base + RTC_WRTGR, 1); + if (ret < 0) + return ret; + + while (1) { + ret = regmap_read(rtc->regmap, rtc->addr_base + RTC_BBPU, + &data); + if (ret < 0) + break; + if (!(data & RTC_BBPU_CBUSY)) + break; + if (time_after(jiffies, timeout)) { + ret = -ETIMEDOUT; + break; + } + cpu_relax(); + } + + return ret; +} + +static irqreturn_t mtk_rtc_irq_handler_thread(int irq, void *data) +{ + struct mt6397_rtc *rtc = data; + u32 irqsta, irqen; + int ret; + + ret = regmap_read(rtc->regmap, rtc->addr_base + RTC_IRQ_STA, &irqsta); + if ((ret >= 0) && (irqsta & RTC_IRQ_STA_AL)) { + rtc_update_irq(rtc->rtc_dev, 1, RTC_IRQF | RTC_AF); + irqen = irqsta & ~RTC_IRQ_EN_AL; + mutex_lock(&rtc->lock); + if (regmap_write(rtc->regmap, rtc->addr_base + RTC_IRQ_EN, + irqen) < 0) + mtk_rtc_write_trigger(rtc); + mutex_unlock(&rtc->lock); + + return IRQ_HANDLED; + } + + return IRQ_NONE; +} + +static int __mtk_rtc_read_time(struct mt6397_rtc *rtc, + struct rtc_time *tm, int *sec) +{ + int ret; + u16 data[RTC_OFFSET_COUNT]; + + mutex_lock(&rtc->lock); + ret = regmap_bulk_read(rtc->regmap, rtc->addr_base + RTC_TC_SEC, + data, RTC_OFFSET_COUNT); + if (ret < 0) + goto exit; + + tm->tm_sec = data[RTC_OFFSET_SEC]; + tm->tm_min = data[RTC_OFFSET_MIN]; + tm->tm_hour = data[RTC_OFFSET_HOUR]; + tm->tm_mday = data[RTC_OFFSET_DOM]; + tm->tm_mon = data[RTC_OFFSET_MTH]; + tm->tm_year = data[RTC_OFFSET_YEAR]; + + ret = regmap_read(rtc->regmap, rtc->addr_base + RTC_TC_SEC, sec); +exit: + mutex_unlock(&rtc->lock); + return ret; +} + +static int mtk_rtc_read_time(struct device *dev, struct rtc_time *tm) +{ + time64_t time; + struct mt6397_rtc *rtc = dev_get_drvdata(dev); + int days, sec, ret; + + do { + ret = __mtk_rtc_read_time(rtc, tm, &sec); + if (ret < 0) + goto exit; + } while (sec < tm->tm_sec); + + /* HW register use 7 bits to store year data, minus + * RTC_MIN_YEAR_OFFSET before write year data to register, and plus + * RTC_MIN_YEAR_OFFSET back after read year from register + */ + tm->tm_year += RTC_MIN_YEAR_OFFSET; + + /* HW register start mon from one, but tm_mon start from zero. */ + tm->tm_mon--; + time = rtc_tm_to_time64(tm); + + /* rtc_tm_to_time64 covert Gregorian date to seconds since + * 01-01-1970 00:00:00, and this date is Thursday. + */ + days = div_s64(time, 86400); + tm->tm_wday = (days + 4) % 7; + +exit: + return ret; +} + +static int mtk_rtc_set_time(struct device *dev, struct rtc_time *tm) +{ + struct mt6397_rtc *rtc = dev_get_drvdata(dev); + int ret; + u16 data[RTC_OFFSET_COUNT]; + + tm->tm_year -= RTC_MIN_YEAR_OFFSET; + tm->tm_mon++; + + data[RTC_OFFSET_SEC] = tm->tm_sec; + data[RTC_OFFSET_MIN] = tm->tm_min; + data[RTC_OFFSET_HOUR] = tm->tm_hour; + data[RTC_OFFSET_DOM] = tm->tm_mday; + data[RTC_OFFSET_MTH] = tm->tm_mon; + data[RTC_OFFSET_YEAR] = tm->tm_year; + + mutex_lock(&rtc->lock); + ret = regmap_bulk_write(rtc->regmap, rtc->addr_base + RTC_TC_SEC, + data, RTC_OFFSET_COUNT); + if (ret < 0) + goto exit; + + /* Time register write to hardware after call trigger function */ + ret = mtk_rtc_write_trigger(rtc); + +exit: + mutex_unlock(&rtc->lock); + return ret; +} + +static int mtk_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alm) +{ + struct rtc_time *tm = &alm->time; + struct mt6397_rtc *rtc = dev_get_drvdata(dev); + u32 irqen, pdn2; + int ret; + u16 data[RTC_OFFSET_COUNT]; + + mutex_lock(&rtc->lock); + ret = regmap_read(rtc->regmap, rtc->addr_base + RTC_IRQ_EN, &irqen); + if (ret < 0) + goto err_exit; + ret = regmap_read(rtc->regmap, rtc->addr_base + RTC_PDN2, &pdn2); + if (ret < 0) + goto err_exit; + + ret = regmap_bulk_read(rtc->regmap, rtc->addr_base + RTC_AL_SEC, + data, RTC_OFFSET_COUNT); + if (ret < 0) + goto err_exit; + + alm->enabled = !!(irqen & RTC_IRQ_EN_AL); + alm->pending = !!(pdn2 & RTC_PDN2_PWRON_ALARM); + mutex_unlock(&rtc->lock); + + tm->tm_sec = data[RTC_OFFSET_SEC]; + tm->tm_min = data[RTC_OFFSET_MIN]; + tm->tm_hour = data[RTC_OFFSET_HOUR]; + tm->tm_mday = data[RTC_OFFSET_DOM]; + tm->tm_mon = data[RTC_OFFSET_MTH]; + tm->tm_year = data[RTC_OFFSET_YEAR]; + + tm->tm_year += RTC_MIN_YEAR_OFFSET; + tm->tm_mon--; + + return 0; +err_exit: + mutex_unlock(&rtc->lock); + return ret; +} + +static int mtk_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alm) +{ + struct rtc_time *tm = &alm->time; + struct mt6397_rtc *rtc = dev_get_drvdata(dev); + int ret; + u16 data[RTC_OFFSET_COUNT]; + + tm->tm_year -= RTC_MIN_YEAR_OFFSET; + tm->tm_mon++; + + data[RTC_OFFSET_SEC] = tm->tm_sec; + data[RTC_OFFSET_MIN] = tm->tm_min; + data[RTC_OFFSET_HOUR] = tm->tm_hour; + data[RTC_OFFSET_DOM] = tm->tm_mday; + data[RTC_OFFSET_MTH] = tm->tm_mon; + data[RTC_OFFSET_YEAR] = tm->tm_year; + + mutex_lock(&rtc->lock); + if (alm->enabled) { + ret = regmap_bulk_write(rtc->regmap, + rtc->addr_base + RTC_AL_SEC, + data, RTC_OFFSET_COUNT); + if (ret < 0) + goto exit; + ret = regmap_write(rtc->regmap, rtc->addr_base + RTC_AL_MASK, + RTC_AL_MASK_DOW); + if (ret < 0) + goto exit; + ret = regmap_update_bits(rtc->regmap, + rtc->addr_base + RTC_IRQ_EN, + RTC_IRQ_EN_ONESHOT_AL, + RTC_IRQ_EN_ONESHOT_AL); + if (ret < 0) + goto exit; + } else { + ret = regmap_update_bits(rtc->regmap, + rtc->addr_base + RTC_IRQ_EN, + RTC_IRQ_EN_ONESHOT_AL, 0); + if (ret < 0) + goto exit; + } + + /* All alarm time register write to hardware after calling + * mtk_rtc_write_trigger. This can avoid race condition if alarm + * occur happen during writing alarm time register. + */ + ret = mtk_rtc_write_trigger(rtc); +exit: + mutex_unlock(&rtc->lock); + return ret; +} + +static struct rtc_class_ops mtk_rtc_ops = { + .read_time = mtk_rtc_read_time, + .set_time = mtk_rtc_set_time, + .read_alarm = mtk_rtc_read_alarm, + .set_alarm = mtk_rtc_set_alarm, +}; + +static int mtk_rtc_probe(struct platform_device *pdev) +{ + struct resource *res; + struct mt6397_chip *mt6397_chip = dev_get_drvdata(pdev->dev.parent); + struct mt6397_rtc *rtc; + int ret; + + rtc = devm_kzalloc(&pdev->dev, sizeof(struct mt6397_rtc), GFP_KERNEL); + if (!rtc) + return -ENOMEM; + + res = platform_get_resource(pdev, IORESOURCE_MEM, 0); + rtc->addr_base = res->start; + + res = platform_get_resource(pdev, IORESOURCE_IRQ, 0); + rtc->irq = irq_create_mapping(mt6397_chip->irq_domain, res->start); + if (rtc->irq <= 0) + return -EINVAL; + + rtc->regmap = mt6397_chip->regmap; + rtc->dev = &pdev->dev; + mutex_init(&rtc->lock); + + platform_set_drvdata(pdev, rtc); + + ret = request_threaded_irq(rtc->irq, NULL, + mtk_rtc_irq_handler_thread, + IRQF_ONESHOT | IRQF_TRIGGER_HIGH, + "mt6397-rtc", rtc); + if (ret) { + dev_err(&pdev->dev, "Failed to request alarm IRQ: %d: %d\n", + rtc->irq, ret); + goto out_dispose_irq; + } + + device_init_wakeup(&pdev->dev, 1); + + rtc->rtc_dev = rtc_device_register("mt6397-rtc", &pdev->dev, + &mtk_rtc_ops, THIS_MODULE); + if (IS_ERR(rtc->rtc_dev)) { + dev_err(&pdev->dev, "register rtc device failed\n"); + ret = PTR_ERR(rtc->rtc_dev); + goto out_free_irq; + } + + return 0; + +out_free_irq: + free_irq(rtc->irq, rtc->rtc_dev); +out_dispose_irq: + irq_dispose_mapping(rtc->irq); + return ret; +} + +static int mtk_rtc_remove(struct platform_device *pdev) +{ + struct mt6397_rtc *rtc = platform_get_drvdata(pdev); + + rtc_device_unregister(rtc->rtc_dev); + free_irq(rtc->irq, rtc->rtc_dev); + irq_dispose_mapping(rtc->irq); + + return 0; +} + +static const struct of_device_id mt6397_rtc_of_match[] = { + { .compatible = "mediatek,mt6397-rtc", }, + { } +}; + +static struct platform_driver mtk_rtc_driver = { + .driver = { + .name = "mt6397-rtc", + .of_match_table = mt6397_rtc_of_match, + }, + .probe = mtk_rtc_probe, + .remove = mtk_rtc_remove, +}; + +module_platform_driver(mtk_rtc_driver); + +MODULE_LICENSE("GPL v2"); +MODULE_AUTHOR("Tianping Fang <tianping.fang@mediatek.com>"); +MODULE_DESCRIPTION("RTC Driver for MediaTek MT6397 PMIC"); +MODULE_ALIAS("platform:mt6397-rtc"); |