diff options
Diffstat (limited to 'drivers/rtc/rtc-asm9260.c')
| -rw-r--r-- | drivers/rtc/rtc-asm9260.c | 355 |
1 files changed, 355 insertions, 0 deletions
diff --git a/drivers/rtc/rtc-asm9260.c b/drivers/rtc/rtc-asm9260.c new file mode 100644 index 000000000000..14e08c4c1a01 --- /dev/null +++ b/drivers/rtc/rtc-asm9260.c @@ -0,0 +1,355 @@ +/* + * 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; + /* io lock */ + spinlock_t lock; +}; + +static irqreturn_t asm9260_rtc_irq(int irq, void *dev_id) +{ + struct asm9260_rtc_priv *priv = dev_id; + u32 isr; + unsigned long events = 0; + + isr = ioread32(priv->iobase + HW_CIIR); + if (!isr) + return IRQ_NONE; + + iowrite32(0, priv->iobase + HW_CIIR); + + 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; + unsigned long irq_flags; + + spin_lock_irqsave(&priv->lock, irq_flags); + 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); + } + spin_unlock_irqrestore(&priv->lock, irq_flags); + + 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); + unsigned long irq_flags; + + spin_lock_irqsave(&priv->lock, irq_flags); + /* + * 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); + spin_unlock_irqrestore(&priv->lock, irq_flags); + + return 0; +} + +static int asm9260_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alrm) +{ + struct asm9260_rtc_priv *priv = dev_get_drvdata(dev); + unsigned long irq_flags; + + spin_lock_irqsave(&priv->lock, irq_flags); + 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; + spin_unlock_irqrestore(&priv->lock, irq_flags); + + 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); + unsigned long irq_flags; + + spin_lock_irqsave(&priv->lock, irq_flags); + 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); + spin_unlock_irqrestore(&priv->lock, irq_flags); + + 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 __init 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 __exit 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", }, + {} +}; + +static struct platform_driver asm9260_rtc_driver = { + .probe = asm9260_rtc_probe, + .remove = asm9260_rtc_remove, + .driver = { + .name = "asm9260-rtc", + .owner = THIS_MODULE, + .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"); |