// SPDX-License-Identifier: GPL-2.0+ /* * Renesas RZ/N1 Real Time Clock interface for Linux * * Copyright: * - 2014 Renesas Electronics Europe Limited * - 2022 Schneider Electric * * Authors: * - Michel Pollet , * - Miquel Raynal */ #include #include #include #include #include #include #include #include #define RZN1_RTC_CTL0 0x00 #define RZN1_RTC_CTL0_SLSB_SUBU 0 #define RZN1_RTC_CTL0_SLSB_SCMP BIT(4) #define RZN1_RTC_CTL0_AMPM BIT(5) #define RZN1_RTC_CTL0_CE BIT(7) #define RZN1_RTC_CTL1 0x04 #define RZN1_RTC_CTL1_ALME BIT(4) #define RZN1_RTC_CTL2 0x08 #define RZN1_RTC_CTL2_WAIT BIT(0) #define RZN1_RTC_CTL2_WST BIT(1) #define RZN1_RTC_CTL2_WUST BIT(5) #define RZN1_RTC_CTL2_STOPPED (RZN1_RTC_CTL2_WAIT | RZN1_RTC_CTL2_WST) #define RZN1_RTC_SEC 0x14 #define RZN1_RTC_MIN 0x18 #define RZN1_RTC_HOUR 0x1c #define RZN1_RTC_WEEK 0x20 #define RZN1_RTC_DAY 0x24 #define RZN1_RTC_MONTH 0x28 #define RZN1_RTC_YEAR 0x2c #define RZN1_RTC_SUBU 0x38 #define RZN1_RTC_SUBU_DEV BIT(7) #define RZN1_RTC_SUBU_DECR BIT(6) #define RZN1_RTC_ALM 0x40 #define RZN1_RTC_ALH 0x44 #define RZN1_RTC_ALW 0x48 #define RZN1_RTC_SECC 0x4c #define RZN1_RTC_MINC 0x50 #define RZN1_RTC_HOURC 0x54 #define RZN1_RTC_WEEKC 0x58 #define RZN1_RTC_DAYC 0x5c #define RZN1_RTC_MONTHC 0x60 #define RZN1_RTC_YEARC 0x64 struct rzn1_rtc { struct rtc_device *rtcdev; void __iomem *base; }; static void rzn1_rtc_get_time_snapshot(struct rzn1_rtc *rtc, struct rtc_time *tm) { tm->tm_sec = readl(rtc->base + RZN1_RTC_SECC); tm->tm_min = readl(rtc->base + RZN1_RTC_MINC); tm->tm_hour = readl(rtc->base + RZN1_RTC_HOURC); tm->tm_wday = readl(rtc->base + RZN1_RTC_WEEKC); tm->tm_mday = readl(rtc->base + RZN1_RTC_DAYC); tm->tm_mon = readl(rtc->base + RZN1_RTC_MONTHC); tm->tm_year = readl(rtc->base + RZN1_RTC_YEARC); } static unsigned int rzn1_rtc_tm_to_wday(struct rtc_time *tm) { time64_t time; unsigned int days; u32 secs; time = rtc_tm_to_time64(tm); days = div_s64_rem(time, 86400, &secs); /* day of the week, 1970-01-01 was a Thursday */ return (days + 4) % 7; } static int rzn1_rtc_read_time(struct device *dev, struct rtc_time *tm) { struct rzn1_rtc *rtc = dev_get_drvdata(dev); u32 val, secs; /* * The RTC was not started or is stopped and thus does not carry the * proper time/date. */ val = readl(rtc->base + RZN1_RTC_CTL2); if (val & RZN1_RTC_CTL2_STOPPED) return -EINVAL; rzn1_rtc_get_time_snapshot(rtc, tm); secs = readl(rtc->base + RZN1_RTC_SECC); if (tm->tm_sec != secs) rzn1_rtc_get_time_snapshot(rtc, tm); tm->tm_sec = bcd2bin(tm->tm_sec); tm->tm_min = bcd2bin(tm->tm_min); tm->tm_hour = bcd2bin(tm->tm_hour); tm->tm_wday = bcd2bin(tm->tm_wday); tm->tm_mday = bcd2bin(tm->tm_mday); tm->tm_mon = bcd2bin(tm->tm_mon); tm->tm_year = bcd2bin(tm->tm_year); return 0; } static int rzn1_rtc_set_time(struct device *dev, struct rtc_time *tm) { struct rzn1_rtc *rtc = dev_get_drvdata(dev); u32 val; int ret; tm->tm_sec = bin2bcd(tm->tm_sec); tm->tm_min = bin2bcd(tm->tm_min); tm->tm_hour = bin2bcd(tm->tm_hour); tm->tm_wday = bin2bcd(rzn1_rtc_tm_to_wday(tm)); tm->tm_mday = bin2bcd(tm->tm_mday); tm->tm_mon = bin2bcd(tm->tm_mon); tm->tm_year = bin2bcd(tm->tm_year); val = readl(rtc->base + RZN1_RTC_CTL2); if (!(val & RZN1_RTC_CTL2_STOPPED)) { /* Hold the counter if it was counting up */ writel(RZN1_RTC_CTL2_WAIT, rtc->base + RZN1_RTC_CTL2); /* Wait for the counter to stop: two 32k clock cycles */ usleep_range(61, 100); ret = readl_poll_timeout(rtc->base + RZN1_RTC_CTL2, val, val & RZN1_RTC_CTL2_WST, 0, 100); if (ret) return ret; } writel(tm->tm_sec, rtc->base + RZN1_RTC_SEC); writel(tm->tm_min, rtc->base + RZN1_RTC_MIN); writel(tm->tm_hour, rtc->base + RZN1_RTC_HOUR); writel(tm->tm_wday, rtc->base + RZN1_RTC_WEEK); writel(tm->tm_mday, rtc->base + RZN1_RTC_DAY); writel(tm->tm_mon, rtc->base + RZN1_RTC_MONTH); writel(tm->tm_year, rtc->base + RZN1_RTC_YEAR); writel(0, rtc->base + RZN1_RTC_CTL2); return 0; } static irqreturn_t rzn1_rtc_alarm_irq(int irq, void *dev_id) { struct rzn1_rtc *rtc = dev_id; rtc_update_irq(rtc->rtcdev, 1, RTC_AF | RTC_IRQF); return IRQ_HANDLED; } static int rzn1_rtc_alarm_irq_enable(struct device *dev, unsigned int enable) { struct rzn1_rtc *rtc = dev_get_drvdata(dev); u32 ctl1 = readl(rtc->base + RZN1_RTC_CTL1); if (enable) ctl1 |= RZN1_RTC_CTL1_ALME; else ctl1 &= ~RZN1_RTC_CTL1_ALME; writel(ctl1, rtc->base + RZN1_RTC_CTL1); return 0; } static int rzn1_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alrm) { struct rzn1_rtc *rtc = dev_get_drvdata(dev); struct rtc_time *tm = &alrm->time; unsigned int min, hour, wday, delta_days; time64_t alarm; u32 ctl1; int ret; ret = rzn1_rtc_read_time(dev, tm); if (ret) return ret; min = readl(rtc->base + RZN1_RTC_ALM); hour = readl(rtc->base + RZN1_RTC_ALH); wday = readl(rtc->base + RZN1_RTC_ALW); tm->tm_sec = 0; tm->tm_min = bcd2bin(min); tm->tm_hour = bcd2bin(hour); delta_days = ((fls(wday) - 1) - tm->tm_wday + 7) % 7; tm->tm_wday = fls(wday) - 1; if (delta_days) { alarm = rtc_tm_to_time64(tm) + (delta_days * 86400); rtc_time64_to_tm(alarm, tm); } ctl1 = readl(rtc->base + RZN1_RTC_CTL1); alrm->enabled = !!(ctl1 & RZN1_RTC_CTL1_ALME); return 0; } static int rzn1_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm) { struct rzn1_rtc *rtc = dev_get_drvdata(dev); struct rtc_time *tm = &alrm->time, tm_now; unsigned long alarm, farest; unsigned int days_ahead, wday; int ret; ret = rzn1_rtc_read_time(dev, &tm_now); if (ret) return ret; /* We cannot set alarms more than one week ahead */ farest = rtc_tm_to_time64(&tm_now) + (7 * 86400); alarm = rtc_tm_to_time64(tm); if (time_after(alarm, farest)) return -ERANGE; /* Convert alarm day into week day */ days_ahead = tm->tm_mday - tm_now.tm_mday; wday = (tm_now.tm_wday + days_ahead) % 7; writel(bin2bcd(tm->tm_min), rtc->base + RZN1_RTC_ALM); writel(bin2bcd(tm->tm_hour), rtc->base + RZN1_RTC_ALH); writel(BIT(wday), rtc->base + RZN1_RTC_ALW); rzn1_rtc_alarm_irq_enable(dev, alrm->enabled); return 0; } static int rzn1_rtc_read_offset(struct device *dev, long *offset) { struct rzn1_rtc *rtc = dev_get_drvdata(dev); unsigned int ppb_per_step; bool subtract; u32 val; val = readl(rtc->base + RZN1_RTC_SUBU); ppb_per_step = val & RZN1_RTC_SUBU_DEV ? 1017 : 3051; subtract = val & RZN1_RTC_SUBU_DECR; val &= 0x3F; if (!val) *offset = 0; else if (subtract) *offset = -(((~val) & 0x3F) + 1) * ppb_per_step; else *offset = (val - 1) * ppb_per_step; return 0; } static int rzn1_rtc_set_offset(struct device *dev, long offset) { struct rzn1_rtc *rtc = dev_get_drvdata(dev); unsigned int steps; int stepsh, stepsl; u32 val; int ret; /* * Check which resolution mode (every 20 or 60s) can be used. * Between 2 and 124 clock pulses can be added or substracted. * * In 20s mode, the minimum resolution is 2 / (32768 * 20) which is * close to 3051 ppb. In 60s mode, the resolution is closer to 1017. */ stepsh = DIV_ROUND_CLOSEST(offset, 1017); stepsl = DIV_ROUND_CLOSEST(offset, 3051); if (stepsh >= -0x3E && stepsh <= 0x3E) { /* 1017 ppb per step */ steps = stepsh; val |= RZN1_RTC_SUBU_DEV; } else if (stepsl >= -0x3E && stepsl <= 0x3E) { /* 3051 ppb per step */ steps = stepsl; } else { return -ERANGE; } if (!steps) return 0; if (steps > 0) { val |= steps + 1; } else { val |= RZN1_RTC_SUBU_DECR; val |= (~(-steps - 1)) & 0x3F; } ret = readl_poll_timeout(rtc->base + RZN1_RTC_CTL2, val, !(val & RZN1_RTC_CTL2_WUST), 100, 2000000); if (ret) return ret; writel(val, rtc->base + RZN1_RTC_SUBU); return 0; } static const struct rtc_class_ops rzn1_rtc_ops = { .read_time = rzn1_rtc_read_time, .set_time = rzn1_rtc_set_time, .read_alarm = rzn1_rtc_read_alarm, .set_alarm = rzn1_rtc_set_alarm, .alarm_irq_enable = rzn1_rtc_alarm_irq_enable, .read_offset = rzn1_rtc_read_offset, .set_offset = rzn1_rtc_set_offset, }; static int rzn1_rtc_probe(struct platform_device *pdev) { struct rzn1_rtc *rtc; int alarm_irq; int ret; rtc = devm_kzalloc(&pdev->dev, sizeof(*rtc), GFP_KERNEL); if (!rtc) return -ENOMEM; platform_set_drvdata(pdev, rtc); rtc->base = devm_platform_ioremap_resource(pdev, 0); if (IS_ERR(rtc->base)) return dev_err_probe(&pdev->dev, PTR_ERR(rtc->base), "Missing reg\n"); alarm_irq = platform_get_irq(pdev, 0); if (alarm_irq < 0) return alarm_irq; rtc->rtcdev = devm_rtc_allocate_device(&pdev->dev); if (IS_ERR(rtc->rtcdev)) return PTR_ERR(rtc); rtc->rtcdev->range_min = RTC_TIMESTAMP_BEGIN_2000; rtc->rtcdev->range_max = RTC_TIMESTAMP_END_2099; rtc->rtcdev->ops = &rzn1_rtc_ops; set_bit(RTC_FEATURE_ALARM_RES_MINUTE, rtc->rtcdev->features); clear_bit(RTC_FEATURE_UPDATE_INTERRUPT, rtc->rtcdev->features); devm_pm_runtime_enable(&pdev->dev); ret = pm_runtime_resume_and_get(&pdev->dev); if (ret < 0) return ret; /* * Ensure the clock counter is enabled. * Set 24-hour mode and possible oscillator offset compensation in SUBU mode. */ writel(RZN1_RTC_CTL0_CE | RZN1_RTC_CTL0_AMPM | RZN1_RTC_CTL0_SLSB_SUBU, rtc->base + RZN1_RTC_CTL0); /* Disable all interrupts */ writel(0, rtc->base + RZN1_RTC_CTL1); ret = devm_request_irq(&pdev->dev, alarm_irq, rzn1_rtc_alarm_irq, 0, dev_name(&pdev->dev), rtc); if (ret) { dev_err(&pdev->dev, "RTC timer interrupt not available\n"); goto dis_runtime_pm; } ret = devm_rtc_register_device(rtc->rtcdev); if (ret) goto dis_runtime_pm; return 0; dis_runtime_pm: pm_runtime_put(&pdev->dev); return ret; } static int rzn1_rtc_remove(struct platform_device *pdev) { pm_runtime_put(&pdev->dev); return 0; } static const struct of_device_id rzn1_rtc_of_match[] = { { .compatible = "renesas,rzn1-rtc" }, {}, }; MODULE_DEVICE_TABLE(of, rzn1_rtc_of_match); static struct platform_driver rzn1_rtc_driver = { .probe = rzn1_rtc_probe, .remove = rzn1_rtc_remove, .driver = { .name = "rzn1-rtc", .owner = THIS_MODULE, .of_match_table = rzn1_rtc_of_match, }, }; module_platform_driver(rzn1_rtc_driver); MODULE_AUTHOR("Michel Pollet