// 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_TIME 0x30 #define RZN1_RTC_TIME_MIN_SHIFT 8 #define RZN1_RTC_TIME_HOUR_SHIFT 16 #define RZN1_RTC_CAL 0x34 #define RZN1_RTC_CAL_DAY_SHIFT 8 #define RZN1_RTC_CAL_MON_SHIFT 16 #define RZN1_RTC_CAL_YEAR_SHIFT 24 #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_TIMEC 0x68 #define RZN1_RTC_CALC 0x6c 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) { u32 val; val = readl(rtc->base + RZN1_RTC_TIMEC); tm->tm_sec = bcd2bin(val); tm->tm_min = bcd2bin(val >> RZN1_RTC_TIME_MIN_SHIFT); tm->tm_hour = bcd2bin(val >> RZN1_RTC_TIME_HOUR_SHIFT); val = readl(rtc->base + RZN1_RTC_CALC); tm->tm_wday = val & 0x0f; tm->tm_mday = bcd2bin(val >> RZN1_RTC_CAL_DAY_SHIFT); tm->tm_mon = bcd2bin(val >> RZN1_RTC_CAL_MON_SHIFT) - 1; tm->tm_year = bcd2bin(val >> RZN1_RTC_CAL_YEAR_SHIFT) + 100; } 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 != bcd2bin(secs)) rzn1_rtc_get_time_snapshot(rtc, tm); 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; 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; } val = bin2bcd(tm->tm_sec); val |= bin2bcd(tm->tm_min) << RZN1_RTC_TIME_MIN_SHIFT; val |= bin2bcd(tm->tm_hour) << RZN1_RTC_TIME_HOUR_SHIFT; writel(val, rtc->base + RZN1_RTC_TIME); val = tm->tm_wday; val |= bin2bcd(tm->tm_mday) << RZN1_RTC_CAL_DAY_SHIFT; val |= bin2bcd(tm->tm_mon + 1) << RZN1_RTC_CAL_MON_SHIFT; val |= bin2bcd(tm->tm_year - 100) << RZN1_RTC_CAL_YEAR_SHIFT; writel(val, rtc->base + RZN1_RTC_CAL); 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) + rtc->rtcdev->alarm_offset_max; 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); int stepsh, stepsl, steps; u32 subu = 0, ctl2; 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; subu |= 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) { subu |= steps + 1; } else { subu |= RZN1_RTC_SUBU_DECR; subu |= (~(-steps - 1)) & 0x3F; } ret = readl_poll_timeout(rtc->base + RZN1_RTC_CTL2, ctl2, !(ctl2 & RZN1_RTC_CTL2_WUST), 100, 2000000); if (ret) return ret; writel(subu, 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->rtcdev); rtc->rtcdev->range_min = RTC_TIMESTAMP_BEGIN_2000; rtc->rtcdev->range_max = RTC_TIMESTAMP_END_2099; rtc->rtcdev->alarm_offset_max = 7 * 86400; 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); ret = devm_pm_runtime_enable(&pdev->dev); if (ret < 0) return ret; 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 void rzn1_rtc_remove(struct platform_device *pdev) { pm_runtime_put(&pdev->dev); } 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", .of_match_table = rzn1_rtc_of_match, }, }; module_platform_driver(rzn1_rtc_driver); MODULE_AUTHOR("Michel Pollet "); MODULE_AUTHOR("Miquel Raynal