--- /dev/null
+/*
+ * 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");
projects / cascardo / linux.git / commitdiff