Initial import

1 files changed, 289 insertions, 0 deletions

diff --git a/drivers/rtc/rtc-vt8500.c b/drivers/rtc/rtc-vt8500.c
new file mode 100644
index 000000000..a58b6d17e
--- /dev/null
+++ b/drivers/rtc/rtc-vt8500.c
@@ -0,0 +1,289 @@
+/*
+ * 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");