--- /dev/null
+/*
+ * drivers/rtc/rtc-vt8500.c
+ *
+ * Copyright (C) 2010 Alexey Charkov <alchark@gmail.com>
+ *
+ * Based on rtc-pxa.c
+ *
+ * This software is licensed under the terms of the GNU General Public
+ * License version 2, as published by the Free Software Foundation, and
+ * may be copied, distributed, and modified under those terms.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ */
+
+#include <linux/module.h>
+#include <linux/rtc.h>
+#include <linux/init.h>
+#include <linux/interrupt.h>
+#include <linux/io.h>
+#include <linux/bcd.h>
+#include <linux/platform_device.h>
+#include <linux/slab.h>
+#include <linux/of.h>
+
+/*
+ * Register definitions
+ */
+#define VT8500_RTC_TS 0x00 /* Time set */
+#define VT8500_RTC_DS 0x04 /* Date set */
+#define VT8500_RTC_AS 0x08 /* Alarm set */
+#define VT8500_RTC_CR 0x0c /* Control */
+#define VT8500_RTC_TR 0x10 /* Time read */
+#define VT8500_RTC_DR 0x14 /* Date read */
+#define VT8500_RTC_WS 0x18 /* Write status */
+#define VT8500_RTC_CL 0x20 /* Calibration */
+#define VT8500_RTC_IS 0x24 /* Interrupt status */
+#define VT8500_RTC_ST 0x28 /* Status */
+
+#define INVALID_TIME_BIT (1 << 31)
+
+#define DATE_CENTURY_S 19
+#define DATE_YEAR_S 11
+#define DATE_YEAR_MASK (0xff << DATE_YEAR_S)
+#define DATE_MONTH_S 6
+#define DATE_MONTH_MASK (0x1f << DATE_MONTH_S)
+#define DATE_DAY_MASK 0x3f
+
+#define TIME_DOW_S 20
+#define TIME_DOW_MASK (0x07 << TIME_DOW_S)
+#define TIME_HOUR_S 14
+#define TIME_HOUR_MASK (0x3f << TIME_HOUR_S)
+#define TIME_MIN_S 7
+#define TIME_MIN_MASK (0x7f << TIME_MIN_S)
+#define TIME_SEC_MASK 0x7f
+
+#define ALARM_DAY_S 20
+#define ALARM_DAY_MASK (0x3f << ALARM_DAY_S)
+
+#define ALARM_DAY_BIT (1 << 29)
+#define ALARM_HOUR_BIT (1 << 28)
+#define ALARM_MIN_BIT (1 << 27)
+#define ALARM_SEC_BIT (1 << 26)
+
+#define ALARM_ENABLE_MASK (ALARM_DAY_BIT \
+ | ALARM_HOUR_BIT \
+ | ALARM_MIN_BIT \
+ | ALARM_SEC_BIT)
+
+#define VT8500_RTC_CR_ENABLE (1 << 0) /* Enable RTC */
+#define VT8500_RTC_CR_12H (1 << 1) /* 12h time format */
+#define VT8500_RTC_CR_SM_ENABLE (1 << 2) /* Enable periodic irqs */
+#define VT8500_RTC_CR_SM_SEC (1 << 3) /* 0: 1Hz/60, 1: 1Hz */
+#define VT8500_RTC_CR_CALIB (1 << 4) /* Enable calibration */
+
+#define VT8500_RTC_IS_ALARM (1 << 0) /* Alarm interrupt status */
+
+struct vt8500_rtc {
+ void __iomem *regbase;
+ int irq_alarm;
+ struct rtc_device *rtc;
+ spinlock_t lock; /* Protects this structure */
+};
+
+static irqreturn_t vt8500_rtc_irq(int irq, void *dev_id)
+{
+ struct vt8500_rtc *vt8500_rtc = dev_id;
+ u32 isr;
+ unsigned long events = 0;
+
+ spin_lock(&vt8500_rtc->lock);
+
+ /* clear interrupt sources */
+ isr = readl(vt8500_rtc->regbase + VT8500_RTC_IS);
+ writel(isr, vt8500_rtc->regbase + VT8500_RTC_IS);
+
+ spin_unlock(&vt8500_rtc->lock);
+
+ if (isr & VT8500_RTC_IS_ALARM)
+ events |= RTC_AF | RTC_IRQF;
+
+ rtc_update_irq(vt8500_rtc->rtc, 1, events);
+
+ return IRQ_HANDLED;
+}
+
+static int vt8500_rtc_read_time(struct device *dev, struct rtc_time *tm)
+{
+ struct vt8500_rtc *vt8500_rtc = dev_get_drvdata(dev);
+ u32 date, time;
+
+ date = readl(vt8500_rtc->regbase + VT8500_RTC_DR);
+ time = readl(vt8500_rtc->regbase + VT8500_RTC_TR);
+
+ tm->tm_sec = bcd2bin(time & TIME_SEC_MASK);
+ tm->tm_min = bcd2bin((time & TIME_MIN_MASK) >> TIME_MIN_S);
+ tm->tm_hour = bcd2bin((time & TIME_HOUR_MASK) >> TIME_HOUR_S);
+ tm->tm_mday = bcd2bin(date & DATE_DAY_MASK);
+ tm->tm_mon = bcd2bin((date & DATE_MONTH_MASK) >> DATE_MONTH_S) - 1;
+ tm->tm_year = bcd2bin((date & DATE_YEAR_MASK) >> DATE_YEAR_S)
+ + ((date >> DATE_CENTURY_S) & 1 ? 200 : 100);
+ tm->tm_wday = (time & TIME_DOW_MASK) >> TIME_DOW_S;
+
+ return 0;
+}
+
+static int vt8500_rtc_set_time(struct device *dev, struct rtc_time *tm)
+{
+ struct vt8500_rtc *vt8500_rtc = dev_get_drvdata(dev);
+
+ if (tm->tm_year < 100) {
+ dev_warn(dev, "Only years 2000-2199 are supported by the "
+ "hardware!\n");
+ return -EINVAL;
+ }
+
+ writel((bin2bcd(tm->tm_year % 100) << DATE_YEAR_S)
+ | (bin2bcd(tm->tm_mon + 1) << DATE_MONTH_S)
+ | (bin2bcd(tm->tm_mday))
+ | ((tm->tm_year >= 200) << DATE_CENTURY_S),
+ vt8500_rtc->regbase + VT8500_RTC_DS);
+ writel((bin2bcd(tm->tm_wday) << TIME_DOW_S)
+ | (bin2bcd(tm->tm_hour) << TIME_HOUR_S)
+ | (bin2bcd(tm->tm_min) << TIME_MIN_S)
+ | (bin2bcd(tm->tm_sec)),
+ vt8500_rtc->regbase + VT8500_RTC_TS);
+
+ return 0;
+}
+
+static int vt8500_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alrm)
+{
+ struct vt8500_rtc *vt8500_rtc = dev_get_drvdata(dev);
+ u32 isr, alarm;
+
+ alarm = readl(vt8500_rtc->regbase + VT8500_RTC_AS);
+ isr = readl(vt8500_rtc->regbase + VT8500_RTC_IS);
+
+ alrm->time.tm_mday = bcd2bin((alarm & ALARM_DAY_MASK) >> ALARM_DAY_S);
+ alrm->time.tm_hour = bcd2bin((alarm & TIME_HOUR_MASK) >> TIME_HOUR_S);
+ alrm->time.tm_min = bcd2bin((alarm & TIME_MIN_MASK) >> TIME_MIN_S);
+ alrm->time.tm_sec = bcd2bin((alarm & TIME_SEC_MASK));
+
+ alrm->enabled = (alarm & ALARM_ENABLE_MASK) ? 1 : 0;
+ alrm->pending = (isr & VT8500_RTC_IS_ALARM) ? 1 : 0;
+
+ return rtc_valid_tm(&alrm->time);
+}
+
+static int vt8500_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm)
+{
+ struct vt8500_rtc *vt8500_rtc = dev_get_drvdata(dev);
+
+ writel((alrm->enabled ? ALARM_ENABLE_MASK : 0)
+ | (bin2bcd(alrm->time.tm_mday) << ALARM_DAY_S)
+ | (bin2bcd(alrm->time.tm_hour) << TIME_HOUR_S)
+ | (bin2bcd(alrm->time.tm_min) << TIME_MIN_S)
+ | (bin2bcd(alrm->time.tm_sec)),
+ vt8500_rtc->regbase + VT8500_RTC_AS);
+
+ return 0;
+}
+
+static int vt8500_alarm_irq_enable(struct device *dev, unsigned int enabled)
+{
+ struct vt8500_rtc *vt8500_rtc = dev_get_drvdata(dev);
+ unsigned long tmp = readl(vt8500_rtc->regbase + VT8500_RTC_AS);
+
+ if (enabled)
+ tmp |= ALARM_ENABLE_MASK;
+ else
+ tmp &= ~ALARM_ENABLE_MASK;
+
+ writel(tmp, vt8500_rtc->regbase + VT8500_RTC_AS);
+ return 0;
+}
+
+static const struct rtc_class_ops vt8500_rtc_ops = {
+ .read_time = vt8500_rtc_read_time,
+ .set_time = vt8500_rtc_set_time,
+ .read_alarm = vt8500_rtc_read_alarm,
+ .set_alarm = vt8500_rtc_set_alarm,
+ .alarm_irq_enable = vt8500_alarm_irq_enable,
+};
+
+static int vt8500_rtc_probe(struct platform_device *pdev)
+{
+ struct vt8500_rtc *vt8500_rtc;
+ struct resource *res;
+ int ret;
+
+ vt8500_rtc = devm_kzalloc(&pdev->dev,
+ sizeof(struct vt8500_rtc), GFP_KERNEL);
+ if (!vt8500_rtc)
+ return -ENOMEM;
+
+ spin_lock_init(&vt8500_rtc->lock);
+ platform_set_drvdata(pdev, vt8500_rtc);
+
+ vt8500_rtc->irq_alarm = platform_get_irq(pdev, 0);
+ if (vt8500_rtc->irq_alarm < 0) {
+ dev_err(&pdev->dev, "No alarm IRQ resource defined\n");
+ return vt8500_rtc->irq_alarm;
+ }
+
+ res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+ vt8500_rtc->regbase = devm_ioremap_resource(&pdev->dev, res);
+ if (IS_ERR(vt8500_rtc->regbase))
+ return PTR_ERR(vt8500_rtc->regbase);
+
+ /* Enable RTC and set it to 24-hour mode */
+ writel(VT8500_RTC_CR_ENABLE,
+ vt8500_rtc->regbase + VT8500_RTC_CR);
+
+ vt8500_rtc->rtc = devm_rtc_device_register(&pdev->dev, "vt8500-rtc",
+ &vt8500_rtc_ops, THIS_MODULE);
+ if (IS_ERR(vt8500_rtc->rtc)) {
+ ret = PTR_ERR(vt8500_rtc->rtc);
+ dev_err(&pdev->dev,
+ "Failed to register RTC device -> %d\n", ret);
+ goto err_return;
+ }
+
+ ret = devm_request_irq(&pdev->dev, vt8500_rtc->irq_alarm,
+ vt8500_rtc_irq, 0, "rtc alarm", vt8500_rtc);
+ if (ret < 0) {
+ dev_err(&pdev->dev, "can't get irq %i, err %d\n",
+ vt8500_rtc->irq_alarm, ret);
+ goto err_return;
+ }
+
+ return 0;
+
+err_return:
+ return ret;
+}
+
+static int vt8500_rtc_remove(struct platform_device *pdev)
+{
+ struct vt8500_rtc *vt8500_rtc = platform_get_drvdata(pdev);
+
+ /* Disable alarm matching */
+ writel(0, vt8500_rtc->regbase + VT8500_RTC_IS);
+
+ return 0;
+}
+
+static const struct of_device_id wmt_dt_ids[] = {
+ { .compatible = "via,vt8500-rtc", },
+ {}
+};
+
+static struct platform_driver vt8500_rtc_driver = {
+ .probe = vt8500_rtc_probe,
+ .remove = vt8500_rtc_remove,
+ .driver = {
+ .name = "vt8500-rtc",
+ .of_match_table = wmt_dt_ids,
+ },
+};
+
+module_platform_driver(vt8500_rtc_driver);
+
+MODULE_AUTHOR("Alexey Charkov <alchark@gmail.com>");
+MODULE_DESCRIPTION("VIA VT8500 SoC Realtime Clock Driver (RTC)");
+MODULE_LICENSE("GPL v2");
+MODULE_ALIAS("platform:vt8500-rtc");
Code Review / kvmfornfv.git / blobdiff