/* * RTC Driver for X-Powers AC100 * * Copyright (c) 2016 Chen-Yu Tsai * * Chen-Yu Tsai * * 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 #include #include #include #include #include #include #include #include #include #include #include /* Control register */ #define AC100_RTC_CTRL_24HOUR BIT(0) /* RTC */ #define AC100_RTC_SEC_MASK GENMASK(6, 0) #define AC100_RTC_MIN_MASK GENMASK(6, 0) #define AC100_RTC_HOU_MASK GENMASK(5, 0) #define AC100_RTC_WEE_MASK GENMASK(2, 0) #define AC100_RTC_DAY_MASK GENMASK(5, 0) #define AC100_RTC_MON_MASK GENMASK(4, 0) #define AC100_RTC_YEA_MASK GENMASK(7, 0) #define AC100_RTC_YEA_LEAP BIT(15) #define AC100_RTC_UPD_TRIGGER BIT(15) /* Alarm (wall clock) */ #define AC100_ALM_INT_ENABLE BIT(0) #define AC100_ALM_SEC_MASK GENMASK(6, 0) #define AC100_ALM_MIN_MASK GENMASK(6, 0) #define AC100_ALM_HOU_MASK GENMASK(5, 0) #define AC100_ALM_WEE_MASK GENMASK(2, 0) #define AC100_ALM_DAY_MASK GENMASK(5, 0) #define AC100_ALM_MON_MASK GENMASK(4, 0) #define AC100_ALM_YEA_MASK GENMASK(7, 0) #define AC100_ALM_ENABLE_FLAG BIT(15) #define AC100_ALM_UPD_TRIGGER BIT(15) /* * The year parameter passed to the driver is usually an offset relative to * the year 1900. This macro is used to convert this offset to another one * relative to the minimum year allowed by the hardware. * * The year range is 1970 - 2069. This range is selected to match Allwinner's * driver. */ #define AC100_YEAR_MIN 1970 #define AC100_YEAR_MAX 2069 #define AC100_YEAR_OFF (AC100_YEAR_MIN - 1900) struct ac100_rtc_dev { struct rtc_device *rtc; struct device *dev; struct regmap *regmap; int irq; unsigned long alarm; }; static int ac100_rtc_get_time(struct device *dev, struct rtc_time *rtc_tm) { struct ac100_rtc_dev *chip = dev_get_drvdata(dev); struct regmap *regmap = chip->regmap; u16 reg[7]; int ret; ret = regmap_bulk_read(regmap, AC100_RTC_SEC, reg, 7); if (ret) return ret; rtc_tm->tm_sec = bcd2bin(reg[0] & AC100_RTC_SEC_MASK); rtc_tm->tm_min = bcd2bin(reg[1] & AC100_RTC_MIN_MASK); rtc_tm->tm_hour = bcd2bin(reg[2] & AC100_RTC_HOU_MASK); rtc_tm->tm_wday = bcd2bin(reg[3] & AC100_RTC_WEE_MASK); rtc_tm->tm_mday = bcd2bin(reg[4] & AC100_RTC_DAY_MASK); rtc_tm->tm_mon = bcd2bin(reg[5] & AC100_RTC_MON_MASK) - 1; rtc_tm->tm_year = bcd2bin(reg[6] & AC100_RTC_YEA_MASK) + AC100_YEAR_OFF; return rtc_valid_tm(rtc_tm); } static int ac100_rtc_set_time(struct device *dev, struct rtc_time *rtc_tm) { struct ac100_rtc_dev *chip = dev_get_drvdata(dev); struct regmap *regmap = chip->regmap; int year; u16 reg[8]; /* our RTC has a limited year range... */ year = rtc_tm->tm_year - AC100_YEAR_OFF; if (year < 0 || year > (AC100_YEAR_MAX - 1900)) { dev_err(dev, "rtc only supports year in range %d - %d\n", AC100_YEAR_MIN, AC100_YEAR_MAX); return -EINVAL; } /* convert to BCD */ reg[0] = bin2bcd(rtc_tm->tm_sec) & AC100_RTC_SEC_MASK; reg[1] = bin2bcd(rtc_tm->tm_min) & AC100_RTC_MIN_MASK; reg[2] = bin2bcd(rtc_tm->tm_hour) & AC100_RTC_HOU_MASK; reg[3] = bin2bcd(rtc_tm->tm_wday) & AC100_RTC_WEE_MASK; reg[4] = bin2bcd(rtc_tm->tm_mday) & AC100_RTC_DAY_MASK; reg[5] = bin2bcd(rtc_tm->tm_mon + 1) & AC100_RTC_MON_MASK; reg[6] = bin2bcd(year) & AC100_RTC_YEA_MASK; /* trigger write */ reg[7] = AC100_RTC_UPD_TRIGGER; /* Is it a leap year? */ if (is_leap_year(year + AC100_YEAR_OFF + 1900)) reg[6] |= AC100_RTC_YEA_LEAP; return regmap_bulk_write(regmap, AC100_RTC_SEC, reg, 8); } static int ac100_rtc_alarm_irq_enable(struct device *dev, unsigned int en) { struct ac100_rtc_dev *chip = dev_get_drvdata(dev); struct regmap *regmap = chip->regmap; unsigned int val; val = en ? AC100_ALM_INT_ENABLE : 0; return regmap_write(regmap, AC100_ALM_INT_ENA, val); } static int ac100_rtc_get_alarm(struct device *dev, struct rtc_wkalrm *alrm) { struct ac100_rtc_dev *chip = dev_get_drvdata(dev); struct regmap *regmap = chip->regmap; struct rtc_time *alrm_tm = &alrm->time; u16 reg[7]; unsigned int val; int ret; ret = regmap_read(regmap, AC100_ALM_INT_ENA, &val); if (ret) return ret; alrm->enabled = !!(val & AC100_ALM_INT_ENABLE); ret = regmap_bulk_read(regmap, AC100_ALM_SEC, reg, 7); if (ret) return ret; alrm_tm->tm_sec = bcd2bin(reg[0] & AC100_ALM_SEC_MASK); alrm_tm->tm_min = bcd2bin(reg[1] & AC100_ALM_MIN_MASK); alrm_tm->tm_hour = bcd2bin(reg[2] & AC100_ALM_HOU_MASK); alrm_tm->tm_wday = bcd2bin(reg[3] & AC100_ALM_WEE_MASK); alrm_tm->tm_mday = bcd2bin(reg[4] & AC100_ALM_DAY_MASK); alrm_tm->tm_mon = bcd2bin(reg[5] & AC100_ALM_MON_MASK) - 1; alrm_tm->tm_year = bcd2bin(reg[6] & AC100_ALM_YEA_MASK) + AC100_YEAR_OFF; return 0; } static int ac100_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm) { struct ac100_rtc_dev *chip = dev_get_drvdata(dev); struct regmap *regmap = chip->regmap; struct rtc_time *alrm_tm = &alrm->time; u16 reg[8]; int year; int ret; /* our alarm has a limited year range... */ year = alrm_tm->tm_year - AC100_YEAR_OFF; if (year < 0 || year > (AC100_YEAR_MAX - 1900)) { dev_err(dev, "alarm only supports year in range %d - %d\n", AC100_YEAR_MIN, AC100_YEAR_MAX); return -EINVAL; } /* convert to BCD */ reg[0] = (bin2bcd(alrm_tm->tm_sec) & AC100_ALM_SEC_MASK) | AC100_ALM_ENABLE_FLAG; reg[1] = (bin2bcd(alrm_tm->tm_min) & AC100_ALM_MIN_MASK) | AC100_ALM_ENABLE_FLAG; reg[2] = (bin2bcd(alrm_tm->tm_hour) & AC100_ALM_HOU_MASK) | AC100_ALM_ENABLE_FLAG; /* Do not enable weekday alarm */ reg[3] = bin2bcd(alrm_tm->tm_wday) & AC100_ALM_WEE_MASK; reg[4] = (bin2bcd(alrm_tm->tm_mday) & AC100_ALM_DAY_MASK) | AC100_ALM_ENABLE_FLAG; reg[5] = (bin2bcd(alrm_tm->tm_mon + 1) & AC100_ALM_MON_MASK) | AC100_ALM_ENABLE_FLAG; reg[6] = (bin2bcd(year) & AC100_ALM_YEA_MASK) | AC100_ALM_ENABLE_FLAG; /* trigger write */ reg[7] = AC100_ALM_UPD_TRIGGER; ret = regmap_bulk_write(regmap, AC100_ALM_SEC, reg, 8); if (ret) return ret; return ac100_rtc_alarm_irq_enable(dev, alrm->enabled); } static irqreturn_t ac100_rtc_irq(int irq, void *data) { struct ac100_rtc_dev *chip = data; struct regmap *regmap = chip->regmap; unsigned int val = 0; int ret; mutex_lock(&chip->rtc->ops_lock); /* read status */ ret = regmap_read(regmap, AC100_ALM_INT_STA, &val); if (ret) goto out; if (val & AC100_ALM_INT_ENABLE) { /* signal rtc framework */ rtc_update_irq(chip->rtc, 1, RTC_AF | RTC_IRQF); /* clear status */ ret = regmap_write(regmap, AC100_ALM_INT_STA, val); if (ret) goto out; /* disable interrupt */ ret = ac100_rtc_alarm_irq_enable(chip->dev, 0); if (ret) goto out; } out: mutex_unlock(&chip->rtc->ops_lock); return IRQ_HANDLED; } static const struct rtc_class_ops ac100_rtc_ops = { .read_time = ac100_rtc_get_time, .set_time = ac100_rtc_set_time, .read_alarm = ac100_rtc_get_alarm, .set_alarm = ac100_rtc_set_alarm, .alarm_irq_enable = ac100_rtc_alarm_irq_enable, }; static int ac100_rtc_probe(struct platform_device *pdev) { struct ac100_dev *ac100 = dev_get_drvdata(pdev->dev.parent); struct ac100_rtc_dev *chip; int ret; chip = devm_kzalloc(&pdev->dev, sizeof(*chip), GFP_KERNEL); platform_set_drvdata(pdev, chip); chip->dev = &pdev->dev; chip->regmap = ac100->regmap; chip->irq = platform_get_irq(pdev, 0); if (chip->irq < 0) { dev_err(&pdev->dev, "No IRQ resource\n"); return chip->irq; } ret = devm_request_threaded_irq(&pdev->dev, chip->irq, NULL, ac100_rtc_irq, IRQF_SHARED | IRQF_ONESHOT, dev_name(&pdev->dev), chip); if (ret) { dev_err(&pdev->dev, "Could not request IRQ\n"); return ret; } /* always use 24 hour mode */ regmap_write_bits(chip->regmap, AC100_RTC_CTRL, AC100_RTC_CTRL_24HOUR, AC100_RTC_CTRL_24HOUR); /* disable counter alarm interrupt */ regmap_write(chip->regmap, AC100_ALM_INT_ENA, 0); /* clear counter alarm pending interrupts */ regmap_write(chip->regmap, AC100_ALM_INT_STA, AC100_ALM_INT_ENABLE); chip->rtc = devm_rtc_device_register(&pdev->dev, "rtc-ac100", &ac100_rtc_ops, THIS_MODULE); if (IS_ERR(chip->rtc)) { dev_err(&pdev->dev, "unable to register device\n"); return PTR_ERR(chip->rtc); } dev_info(&pdev->dev, "RTC enabled\n"); return 0; } static const struct of_device_id ac100_rtc_match[] = { { .compatible = "x-powers,ac100-rtc" }, { }, }; MODULE_DEVICE_TABLE(of, ac100_rtc_match); static struct platform_driver ac100_rtc_driver = { .probe = ac100_rtc_probe, .driver = { .name = "ac100-rtc", .of_match_table = of_match_ptr(ac100_rtc_match), }, }; module_platform_driver(ac100_rtc_driver); MODULE_DESCRIPTION("X-Powers AC100 RTC driver"); MODULE_AUTHOR("Chen-Yu Tsai "); MODULE_LICENSE("GPL v2");