/* * An RTC driver for Allwinner A31/A23 * * Copyright (c) 2014, Chen-Yu Tsai <wens@csie.org> * * based on rtc-sunxi.c * * An RTC driver for Allwinner A10/A20 * * Copyright (c) 2013, Carlo Caione <carlo.caione@gmail.com> * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation; either version 2 of the License, or * (at your option) any later version. * * 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/err.h> #include <linux/fs.h> #include <linux/init.h> #include <linux/interrupt.h> #include <linux/io.h> #include <linux/kernel.h> #include <linux/module.h> #include <linux/of.h> #include <linux/of_address.h> #include <linux/of_device.h> #include <linux/platform_device.h> #include <linux/rtc.h> #include <linux/types.h> /* Control register */ #define SUN6I_LOSC_CTRL 0x0000 #define SUN6I_LOSC_CTRL_ALM_DHMS_ACC BIT(9) #define SUN6I_LOSC_CTRL_RTC_HMS_ACC BIT(8) #define SUN6I_LOSC_CTRL_RTC_YMD_ACC BIT(7) #define SUN6I_LOSC_CTRL_ACC_MASK GENMASK(9, 7) /* RTC */ #define SUN6I_RTC_YMD 0x0010 #define SUN6I_RTC_HMS 0x0014 /* Alarm 0 (counter) */ #define SUN6I_ALRM_COUNTER 0x0020 #define SUN6I_ALRM_CUR_VAL 0x0024 #define SUN6I_ALRM_EN 0x0028 #define SUN6I_ALRM_EN_CNT_EN BIT(0) #define SUN6I_ALRM_IRQ_EN 0x002c #define SUN6I_ALRM_IRQ_EN_CNT_IRQ_EN BIT(0) #define SUN6I_ALRM_IRQ_STA 0x0030 #define SUN6I_ALRM_IRQ_STA_CNT_IRQ_PEND BIT(0) /* Alarm 1 (wall clock) */ #define SUN6I_ALRM1_EN 0x0044 #define SUN6I_ALRM1_IRQ_EN 0x0048 #define SUN6I_ALRM1_IRQ_STA 0x004c #define SUN6I_ALRM1_IRQ_STA_WEEK_IRQ_PEND BIT(0) /* Alarm config */ #define SUN6I_ALARM_CONFIG 0x0050 #define SUN6I_ALARM_CONFIG_WAKEUP BIT(0) /* * Get date values */ #define SUN6I_DATE_GET_DAY_VALUE(x) ((x) & 0x0000001f) #define SUN6I_DATE_GET_MON_VALUE(x) (((x) & 0x00000f00) >> 8) #define SUN6I_DATE_GET_YEAR_VALUE(x) (((x) & 0x003f0000) >> 16) #define SUN6I_LEAP_GET_VALUE(x) (((x) & 0x00400000) >> 22) /* * Get time values */ #define SUN6I_TIME_GET_SEC_VALUE(x) ((x) & 0x0000003f) #define SUN6I_TIME_GET_MIN_VALUE(x) (((x) & 0x00003f00) >> 8) #define SUN6I_TIME_GET_HOUR_VALUE(x) (((x) & 0x001f0000) >> 16) /* * Set date values */ #define SUN6I_DATE_SET_DAY_VALUE(x) ((x) & 0x0000001f) #define SUN6I_DATE_SET_MON_VALUE(x) ((x) << 8 & 0x00000f00) #define SUN6I_DATE_SET_YEAR_VALUE(x) ((x) << 16 & 0x003f0000) #define SUN6I_LEAP_SET_VALUE(x) ((x) << 22 & 0x00400000) /* * Set time values */ #define SUN6I_TIME_SET_SEC_VALUE(x) ((x) & 0x0000003f) #define SUN6I_TIME_SET_MIN_VALUE(x) ((x) << 8 & 0x00003f00) #define SUN6I_TIME_SET_HOUR_VALUE(x) ((x) << 16 & 0x001f0000) /* * 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 - 2033. This range is selected to match Allwinner's * driver, even though it is somewhat limited. */ #define SUN6I_YEAR_MIN 1970 #define SUN6I_YEAR_MAX 2033 #define SUN6I_YEAR_OFF (SUN6I_YEAR_MIN - 1900) struct sun6i_rtc_dev { struct rtc_device *rtc; struct device *dev; void __iomem *base; int irq; unsigned long alarm; }; static irqreturn_t sun6i_rtc_alarmirq(int irq, void *id) { struct sun6i_rtc_dev *chip = (struct sun6i_rtc_dev *) id; u32 val; val = readl(chip->base + SUN6I_ALRM_IRQ_STA); if (val & SUN6I_ALRM_IRQ_STA_CNT_IRQ_PEND) { val |= SUN6I_ALRM_IRQ_STA_CNT_IRQ_PEND; writel(val, chip->base + SUN6I_ALRM_IRQ_STA); rtc_update_irq(chip->rtc, 1, RTC_AF | RTC_IRQF); return IRQ_HANDLED; } return IRQ_NONE; } static void sun6i_rtc_setaie(int to, struct sun6i_rtc_dev *chip) { u32 alrm_val = 0; u32 alrm_irq_val = 0; u32 alrm_wake_val = 0; if (to) { alrm_val = SUN6I_ALRM_EN_CNT_EN; alrm_irq_val = SUN6I_ALRM_IRQ_EN_CNT_IRQ_EN; alrm_wake_val = SUN6I_ALARM_CONFIG_WAKEUP; } else { writel(SUN6I_ALRM_IRQ_STA_CNT_IRQ_PEND, chip->base + SUN6I_ALRM_IRQ_STA); } writel(alrm_val, chip->base + SUN6I_ALRM_EN); writel(alrm_irq_val, chip->base + SUN6I_ALRM_IRQ_EN); writel(alrm_wake_val, chip->base + SUN6I_ALARM_CONFIG); } static int sun6i_rtc_gettime(struct device *dev, struct rtc_time *rtc_tm) { struct sun6i_rtc_dev *chip = dev_get_drvdata(dev); u32 date, time; /* * read again in case it changes */ do { date = readl(chip->base + SUN6I_RTC_YMD); time = readl(chip->base + SUN6I_RTC_HMS); } while ((date != readl(chip->base + SUN6I_RTC_YMD)) || (time != readl(chip->base + SUN6I_RTC_HMS))); rtc_tm->tm_sec = SUN6I_TIME_GET_SEC_VALUE(time); rtc_tm->tm_min = SUN6I_TIME_GET_MIN_VALUE(time); rtc_tm->tm_hour = SUN6I_TIME_GET_HOUR_VALUE(time); rtc_tm->tm_mday = SUN6I_DATE_GET_DAY_VALUE(date); rtc_tm->tm_mon = SUN6I_DATE_GET_MON_VALUE(date); rtc_tm->tm_year = SUN6I_DATE_GET_YEAR_VALUE(date); rtc_tm->tm_mon -= 1; /* * switch from (data_year->min)-relative offset to * a (1900)-relative one */ rtc_tm->tm_year += SUN6I_YEAR_OFF; return rtc_valid_tm(rtc_tm); } static int sun6i_rtc_getalarm(struct device *dev, struct rtc_wkalrm *wkalrm) { struct sun6i_rtc_dev *chip = dev_get_drvdata(dev); u32 alrm_st; u32 alrm_en; alrm_en = readl(chip->base + SUN6I_ALRM_IRQ_EN); alrm_st = readl(chip->base + SUN6I_ALRM_IRQ_STA); wkalrm->enabled = !!(alrm_en & SUN6I_ALRM_EN_CNT_EN); wkalrm->pending = !!(alrm_st & SUN6I_ALRM_EN_CNT_EN); rtc_time_to_tm(chip->alarm, &wkalrm->time); return 0; } static int sun6i_rtc_setalarm(struct device *dev, struct rtc_wkalrm *wkalrm) { struct sun6i_rtc_dev *chip = dev_get_drvdata(dev); struct rtc_time *alrm_tm = &wkalrm->time; struct rtc_time tm_now; unsigned long time_now = 0; unsigned long time_set = 0; unsigned long time_gap = 0; int ret = 0; ret = sun6i_rtc_gettime(dev, &tm_now); if (ret < 0) { dev_err(dev, "Error in getting time\n"); return -EINVAL; } rtc_tm_to_time(alrm_tm, &time_set); rtc_tm_to_time(&tm_now, &time_now); if (time_set <= time_now) { dev_err(dev, "Date to set in the past\n"); return -EINVAL; } time_gap = time_set - time_now; if (time_gap > U32_MAX) { dev_err(dev, "Date too far in the future\n"); return -EINVAL; } sun6i_rtc_setaie(0, chip); writel(0, chip->base + SUN6I_ALRM_COUNTER); usleep_range(100, 300); writel(time_gap, chip->base + SUN6I_ALRM_COUNTER); chip->alarm = time_set; sun6i_rtc_setaie(wkalrm->enabled, chip); return 0; } static int sun6i_rtc_wait(struct sun6i_rtc_dev *chip, int offset, unsigned int mask, unsigned int ms_timeout) { const unsigned long timeout = jiffies + msecs_to_jiffies(ms_timeout); u32 reg; do { reg = readl(chip->base + offset); reg &= mask; if (!reg) return 0; } while (time_before(jiffies, timeout)); return -ETIMEDOUT; } static int sun6i_rtc_settime(struct device *dev, struct rtc_time *rtc_tm) { struct sun6i_rtc_dev *chip = dev_get_drvdata(dev); u32 date = 0; u32 time = 0; int year; year = rtc_tm->tm_year + 1900; if (year < SUN6I_YEAR_MIN || year > SUN6I_YEAR_MAX) { dev_err(dev, "rtc only supports year in range %d - %d\n", SUN6I_YEAR_MIN, SUN6I_YEAR_MAX); return -EINVAL; } rtc_tm->tm_year -= SUN6I_YEAR_OFF; rtc_tm->tm_mon += 1; date = SUN6I_DATE_SET_DAY_VALUE(rtc_tm->tm_mday) | SUN6I_DATE_SET_MON_VALUE(rtc_tm->tm_mon) | SUN6I_DATE_SET_YEAR_VALUE(rtc_tm->tm_year); if (is_leap_year(year)) date |= SUN6I_LEAP_SET_VALUE(1); time = SUN6I_TIME_SET_SEC_VALUE(rtc_tm->tm_sec) | SUN6I_TIME_SET_MIN_VALUE(rtc_tm->tm_min) | SUN6I_TIME_SET_HOUR_VALUE(rtc_tm->tm_hour); /* Check whether registers are writable */ if (sun6i_rtc_wait(chip, SUN6I_LOSC_CTRL, SUN6I_LOSC_CTRL_ACC_MASK, 50)) { dev_err(dev, "rtc is still busy.\n"); return -EBUSY; } writel(time, chip->base + SUN6I_RTC_HMS); /* * After writing the RTC HH-MM-SS register, the * SUN6I_LOSC_CTRL_RTC_HMS_ACC bit is set and it will not * be cleared until the real writing operation is finished */ if (sun6i_rtc_wait(chip, SUN6I_LOSC_CTRL, SUN6I_LOSC_CTRL_RTC_HMS_ACC, 50)) { dev_err(dev, "Failed to set rtc time.\n"); return -ETIMEDOUT; } writel(date, chip->base + SUN6I_RTC_YMD); /* * After writing the RTC YY-MM-DD register, the * SUN6I_LOSC_CTRL_RTC_YMD_ACC bit is set and it will not * be cleared until the real writing operation is finished */ if (sun6i_rtc_wait(chip, SUN6I_LOSC_CTRL, SUN6I_LOSC_CTRL_RTC_YMD_ACC, 50)) { dev_err(dev, "Failed to set rtc time.\n"); return -ETIMEDOUT; } return 0; } static int sun6i_rtc_alarm_irq_enable(struct device *dev, unsigned int enabled) { struct sun6i_rtc_dev *chip = dev_get_drvdata(dev); if (!enabled) sun6i_rtc_setaie(enabled, chip); return 0; } static const struct rtc_class_ops sun6i_rtc_ops = { .read_time = sun6i_rtc_gettime, .set_time = sun6i_rtc_settime, .read_alarm = sun6i_rtc_getalarm, .set_alarm = sun6i_rtc_setalarm, .alarm_irq_enable = sun6i_rtc_alarm_irq_enable }; static int sun6i_rtc_probe(struct platform_device *pdev) { struct sun6i_rtc_dev *chip; struct resource *res; int ret; chip = devm_kzalloc(&pdev->dev, sizeof(*chip), GFP_KERNEL); if (!chip) return -ENOMEM; platform_set_drvdata(pdev, chip); chip->dev = &pdev->dev; res = platform_get_resource(pdev, IORESOURCE_MEM, 0); chip->base = devm_ioremap_resource(&pdev->dev, res); if (IS_ERR(chip->base)) return PTR_ERR(chip->base); 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_irq(&pdev->dev, chip->irq, sun6i_rtc_alarmirq, 0, dev_name(&pdev->dev), chip); if (ret) { dev_err(&pdev->dev, "Could not request IRQ\n"); return ret; } /* clear the alarm counter value */ writel(0, chip->base + SUN6I_ALRM_COUNTER); /* disable counter alarm */ writel(0, chip->base + SUN6I_ALRM_EN); /* disable counter alarm interrupt */ writel(0, chip->base + SUN6I_ALRM_IRQ_EN); /* disable week alarm */ writel(0, chip->base + SUN6I_ALRM1_EN); /* disable week alarm interrupt */ writel(0, chip->base + SUN6I_ALRM1_IRQ_EN); /* clear counter alarm pending interrupts */ writel(SUN6I_ALRM_IRQ_STA_CNT_IRQ_PEND, chip->base + SUN6I_ALRM_IRQ_STA); /* clear week alarm pending interrupts */ writel(SUN6I_ALRM1_IRQ_STA_WEEK_IRQ_PEND, chip->base + SUN6I_ALRM1_IRQ_STA); /* disable alarm wakeup */ writel(0, chip->base + SUN6I_ALARM_CONFIG); chip->rtc = rtc_device_register("rtc-sun6i", &pdev->dev, &sun6i_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 int sun6i_rtc_remove(struct platform_device *pdev) { struct sun6i_rtc_dev *chip = platform_get_drvdata(pdev); rtc_device_unregister(chip->rtc); return 0; } static const struct of_device_id sun6i_rtc_dt_ids[] = { { .compatible = "allwinner,sun6i-a31-rtc" }, { /* sentinel */ }, }; MODULE_DEVICE_TABLE(of, sun6i_rtc_dt_ids); static struct platform_driver sun6i_rtc_driver = { .probe = sun6i_rtc_probe, .remove = sun6i_rtc_remove, .driver = { .name = "sun6i-rtc", .of_match_table = sun6i_rtc_dt_ids, }, }; module_platform_driver(sun6i_rtc_driver); MODULE_DESCRIPTION("sun6i RTC driver"); MODULE_AUTHOR("Chen-Yu Tsai <wens@csie.org>"); MODULE_LICENSE("GPL");