/* * Copyright (C) 2016 Oleksij Rempel <linux@rempel-privat.de> * * 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. */ #include <linux/clk.h> #include <linux/interrupt.h> #include <linux/io.h> #include <linux/module.h> #include <linux/of.h> #include <linux/platform_device.h> #include <linux/rtc.h> /* Miscellaneous registers */ /* Interrupt Location Register */ #define HW_ILR 0x00 #define BM_RTCALF BIT(1) #define BM_RTCCIF BIT(0) /* Clock Control Register */ #define HW_CCR 0x08 /* Calibration counter disable */ #define BM_CCALOFF BIT(4) /* Reset internal oscillator divider */ #define BM_CTCRST BIT(1) /* Clock Enable */ #define BM_CLKEN BIT(0) /* Counter Increment Interrupt Register */ #define HW_CIIR 0x0C #define BM_CIIR_IMYEAR BIT(7) #define BM_CIIR_IMMON BIT(6) #define BM_CIIR_IMDOY BIT(5) #define BM_CIIR_IMDOW BIT(4) #define BM_CIIR_IMDOM BIT(3) #define BM_CIIR_IMHOUR BIT(2) #define BM_CIIR_IMMIN BIT(1) #define BM_CIIR_IMSEC BIT(0) /* Alarm Mask Register */ #define HW_AMR 0x10 #define BM_AMR_IMYEAR BIT(7) #define BM_AMR_IMMON BIT(6) #define BM_AMR_IMDOY BIT(5) #define BM_AMR_IMDOW BIT(4) #define BM_AMR_IMDOM BIT(3) #define BM_AMR_IMHOUR BIT(2) #define BM_AMR_IMMIN BIT(1) #define BM_AMR_IMSEC BIT(0) #define BM_AMR_OFF 0xff /* Consolidated time registers */ #define HW_CTIME0 0x14 #define BM_CTIME0_DOW_S 24 #define BM_CTIME0_DOW_M 0x7 #define BM_CTIME0_HOUR_S 16 #define BM_CTIME0_HOUR_M 0x1f #define BM_CTIME0_MIN_S 8 #define BM_CTIME0_MIN_M 0x3f #define BM_CTIME0_SEC_S 0 #define BM_CTIME0_SEC_M 0x3f #define HW_CTIME1 0x18 #define BM_CTIME1_YEAR_S 16 #define BM_CTIME1_YEAR_M 0xfff #define BM_CTIME1_MON_S 8 #define BM_CTIME1_MON_M 0xf #define BM_CTIME1_DOM_S 0 #define BM_CTIME1_DOM_M 0x1f #define HW_CTIME2 0x1C #define BM_CTIME2_DOY_S 0 #define BM_CTIME2_DOY_M 0xfff /* Time counter registers */ #define HW_SEC 0x20 #define HW_MIN 0x24 #define HW_HOUR 0x28 #define HW_DOM 0x2C #define HW_DOW 0x30 #define HW_DOY 0x34 #define HW_MONTH 0x38 #define HW_YEAR 0x3C #define HW_CALIBRATION 0x40 #define BM_CALDIR_BACK BIT(17) #define BM_CALVAL_M 0x1ffff /* General purpose registers */ #define HW_GPREG0 0x44 #define HW_GPREG1 0x48 #define HW_GPREG2 0x4C #define HW_GPREG3 0x50 #define HW_GPREG4 0x54 /* Alarm register group */ #define HW_ALSEC 0x60 #define HW_ALMIN 0x64 #define HW_ALHOUR 0x68 #define HW_ALDOM 0x6C #define HW_ALDOW 0x70 #define HW_ALDOY 0x74 #define HW_ALMON 0x78 #define HW_ALYEAR 0x7C struct asm9260_rtc_priv { struct device *dev; void __iomem *iobase; struct rtc_device *rtc; struct clk *clk; }; static irqreturn_t asm9260_rtc_irq(int irq, void *dev_id) { struct asm9260_rtc_priv *priv = dev_id; u32 isr; unsigned long events = 0; mutex_lock(&priv->rtc->ops_lock); isr = ioread32(priv->iobase + HW_CIIR); if (!isr) { mutex_unlock(&priv->rtc->ops_lock); return IRQ_NONE; } iowrite32(0, priv->iobase + HW_CIIR); mutex_unlock(&priv->rtc->ops_lock); events |= RTC_AF | RTC_IRQF; rtc_update_irq(priv->rtc, 1, events); return IRQ_HANDLED; } static int asm9260_rtc_read_time(struct device *dev, struct rtc_time *tm) { struct asm9260_rtc_priv *priv = dev_get_drvdata(dev); u32 ctime0, ctime1, ctime2; ctime0 = ioread32(priv->iobase + HW_CTIME0); ctime1 = ioread32(priv->iobase + HW_CTIME1); ctime2 = ioread32(priv->iobase + HW_CTIME2); if (ctime1 != ioread32(priv->iobase + HW_CTIME1)) { /* * woops, counter flipped right now. Now we are safe * to reread. */ ctime0 = ioread32(priv->iobase + HW_CTIME0); ctime1 = ioread32(priv->iobase + HW_CTIME1); ctime2 = ioread32(priv->iobase + HW_CTIME2); } tm->tm_sec = (ctime0 >> BM_CTIME0_SEC_S) & BM_CTIME0_SEC_M; tm->tm_min = (ctime0 >> BM_CTIME0_MIN_S) & BM_CTIME0_MIN_M; tm->tm_hour = (ctime0 >> BM_CTIME0_HOUR_S) & BM_CTIME0_HOUR_M; tm->tm_wday = (ctime0 >> BM_CTIME0_DOW_S) & BM_CTIME0_DOW_M; tm->tm_mday = (ctime1 >> BM_CTIME1_DOM_S) & BM_CTIME1_DOM_M; tm->tm_mon = (ctime1 >> BM_CTIME1_MON_S) & BM_CTIME1_MON_M; tm->tm_year = (ctime1 >> BM_CTIME1_YEAR_S) & BM_CTIME1_YEAR_M; tm->tm_yday = (ctime2 >> BM_CTIME2_DOY_S) & BM_CTIME2_DOY_M; return 0; } static int asm9260_rtc_set_time(struct device *dev, struct rtc_time *tm) { struct asm9260_rtc_priv *priv = dev_get_drvdata(dev); /* * make sure SEC counter will not flip other counter on write time, * real value will be written at the enf of sequence. */ iowrite32(0, priv->iobase + HW_SEC); iowrite32(tm->tm_year, priv->iobase + HW_YEAR); iowrite32(tm->tm_mon, priv->iobase + HW_MONTH); iowrite32(tm->tm_mday, priv->iobase + HW_DOM); iowrite32(tm->tm_wday, priv->iobase + HW_DOW); iowrite32(tm->tm_yday, priv->iobase + HW_DOY); iowrite32(tm->tm_hour, priv->iobase + HW_HOUR); iowrite32(tm->tm_min, priv->iobase + HW_MIN); iowrite32(tm->tm_sec, priv->iobase + HW_SEC); return 0; } static int asm9260_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alrm) { struct asm9260_rtc_priv *priv = dev_get_drvdata(dev); alrm->time.tm_year = ioread32(priv->iobase + HW_ALYEAR); alrm->time.tm_mon = ioread32(priv->iobase + HW_ALMON); alrm->time.tm_mday = ioread32(priv->iobase + HW_ALDOM); alrm->time.tm_wday = ioread32(priv->iobase + HW_ALDOW); alrm->time.tm_yday = ioread32(priv->iobase + HW_ALDOY); alrm->time.tm_hour = ioread32(priv->iobase + HW_ALHOUR); alrm->time.tm_min = ioread32(priv->iobase + HW_ALMIN); alrm->time.tm_sec = ioread32(priv->iobase + HW_ALSEC); alrm->enabled = ioread32(priv->iobase + HW_AMR) ? 1 : 0; alrm->pending = ioread32(priv->iobase + HW_CIIR) ? 1 : 0; return rtc_valid_tm(&alrm->time); } static int asm9260_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm) { struct asm9260_rtc_priv *priv = dev_get_drvdata(dev); iowrite32(alrm->time.tm_year, priv->iobase + HW_ALYEAR); iowrite32(alrm->time.tm_mon, priv->iobase + HW_ALMON); iowrite32(alrm->time.tm_mday, priv->iobase + HW_ALDOM); iowrite32(alrm->time.tm_wday, priv->iobase + HW_ALDOW); iowrite32(alrm->time.tm_yday, priv->iobase + HW_ALDOY); iowrite32(alrm->time.tm_hour, priv->iobase + HW_ALHOUR); iowrite32(alrm->time.tm_min, priv->iobase + HW_ALMIN); iowrite32(alrm->time.tm_sec, priv->iobase + HW_ALSEC); iowrite32(alrm->enabled ? 0 : BM_AMR_OFF, priv->iobase + HW_AMR); return 0; } static int asm9260_alarm_irq_enable(struct device *dev, unsigned int enabled) { struct asm9260_rtc_priv *priv = dev_get_drvdata(dev); iowrite32(enabled ? 0 : BM_AMR_OFF, priv->iobase + HW_AMR); return 0; } static const struct rtc_class_ops asm9260_rtc_ops = { .read_time = asm9260_rtc_read_time, .set_time = asm9260_rtc_set_time, .read_alarm = asm9260_rtc_read_alarm, .set_alarm = asm9260_rtc_set_alarm, .alarm_irq_enable = asm9260_alarm_irq_enable, }; static int asm9260_rtc_probe(struct platform_device *pdev) { struct asm9260_rtc_priv *priv; struct device *dev = &pdev->dev; struct resource *res; int irq_alarm, ret; u32 ccr; priv = devm_kzalloc(dev, sizeof(struct asm9260_rtc_priv), GFP_KERNEL); if (!priv) return -ENOMEM; priv->dev = &pdev->dev; platform_set_drvdata(pdev, priv); irq_alarm = platform_get_irq(pdev, 0); if (irq_alarm < 0) { dev_err(dev, "No alarm IRQ resource defined\n"); return irq_alarm; } res = platform_get_resource(pdev, IORESOURCE_MEM, 0); priv->iobase = devm_ioremap_resource(dev, res); if (IS_ERR(priv->iobase)) return PTR_ERR(priv->iobase); priv->clk = devm_clk_get(dev, "ahb"); ret = clk_prepare_enable(priv->clk); if (ret) { dev_err(dev, "Failed to enable clk!\n"); return ret; } ccr = ioread32(priv->iobase + HW_CCR); /* if dev is not enabled, reset it */ if ((ccr & (BM_CLKEN | BM_CTCRST)) != BM_CLKEN) { iowrite32(BM_CTCRST, priv->iobase + HW_CCR); ccr = 0; } iowrite32(BM_CLKEN | ccr, priv->iobase + HW_CCR); iowrite32(0, priv->iobase + HW_CIIR); iowrite32(BM_AMR_OFF, priv->iobase + HW_AMR); priv->rtc = devm_rtc_device_register(dev, dev_name(dev), &asm9260_rtc_ops, THIS_MODULE); if (IS_ERR(priv->rtc)) { ret = PTR_ERR(priv->rtc); dev_err(dev, "Failed to register RTC device: %d\n", ret); goto err_return; } ret = devm_request_threaded_irq(dev, irq_alarm, NULL, asm9260_rtc_irq, IRQF_ONESHOT, dev_name(dev), priv); if (ret < 0) { dev_err(dev, "can't get irq %i, err %d\n", irq_alarm, ret); goto err_return; } return 0; err_return: clk_disable_unprepare(priv->clk); return ret; } static int asm9260_rtc_remove(struct platform_device *pdev) { struct asm9260_rtc_priv *priv = platform_get_drvdata(pdev); /* Disable alarm matching */ iowrite32(BM_AMR_OFF, priv->iobase + HW_AMR); clk_disable_unprepare(priv->clk); return 0; } static const struct of_device_id asm9260_dt_ids[] = { { .compatible = "alphascale,asm9260-rtc", }, {} }; MODULE_DEVICE_TABLE(of, asm9260_dt_ids); static struct platform_driver asm9260_rtc_driver = { .probe = asm9260_rtc_probe, .remove = asm9260_rtc_remove, .driver = { .name = "asm9260-rtc", .of_match_table = asm9260_dt_ids, }, }; module_platform_driver(asm9260_rtc_driver); MODULE_AUTHOR("Oleksij Rempel <linux@rempel-privat.de>"); MODULE_DESCRIPTION("Alphascale asm9260 SoC Realtime Clock Driver (RTC)"); MODULE_LICENSE("GPL");