Initial import

1 files changed, 287 insertions, 0 deletions

diff --git a/drivers/rtc/rtc-at32ap700x.c b/drivers/rtc/rtc-at32ap700x.c
new file mode 100644
index 000000000..d618d6c7e
--- /dev/null
+++ b/drivers/rtc/rtc-at32ap700x.c
@@ -0,0 +1,287 @@
+/*
+ * An RTC driver for the AVR32 AT32AP700x processor series.
+ *
+ * Copyright (C) 2007 Atmel Corporation
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 as published
+ * by the Free Software Foundation.
+ */
+
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/platform_device.h>
+#include <linux/slab.h>
+#include <linux/rtc.h>
+#include <linux/io.h>
+
+/*
+ * This is a bare-bones RTC. It runs during most system sleep states, but has
+ * no battery backup and gets reset during system restart.  It must be
+ * initialized from an external clock (network, I2C, etc) before it can be of
+ * much use.
+ *
+ * The alarm functionality is limited by the hardware, not supporting
+ * periodic interrupts.
+ */
+
+#define RTC_CTRL		0x00
+#define RTC_CTRL_EN		   0
+#define RTC_CTRL_PCLR		   1
+#define RTC_CTRL_TOPEN		   2
+#define RTC_CTRL_PSEL		   8
+
+#define RTC_VAL			0x04
+
+#define RTC_TOP			0x08
+
+#define RTC_IER			0x10
+#define RTC_IER_TOPI		   0
+
+#define RTC_IDR			0x14
+#define RTC_IDR_TOPI		   0
+
+#define RTC_IMR			0x18
+#define RTC_IMR_TOPI		   0
+
+#define RTC_ISR			0x1c
+#define RTC_ISR_TOPI		   0
+
+#define RTC_ICR			0x20
+#define RTC_ICR_TOPI		   0
+
+#define RTC_BIT(name)		(1 << RTC_##name)
+#define RTC_BF(name, value)	((value) << RTC_##name)
+
+#define rtc_readl(dev, reg)				\
+	__raw_readl((dev)->regs + RTC_##reg)
+#define rtc_writel(dev, reg, value)			\
+	__raw_writel((value), (dev)->regs + RTC_##reg)
+
+struct rtc_at32ap700x {
+	struct rtc_device	*rtc;
+	void __iomem		*regs;
+	unsigned long		alarm_time;
+	unsigned long		irq;
+	/* Protect against concurrent register access. */
+	spinlock_t		lock;
+};
+
+static int at32_rtc_readtime(struct device *dev, struct rtc_time *tm)
+{
+	struct rtc_at32ap700x *rtc = dev_get_drvdata(dev);
+	unsigned long now;
+
+	now = rtc_readl(rtc, VAL);
+	rtc_time_to_tm(now, tm);
+
+	return 0;
+}
+
+static int at32_rtc_settime(struct device *dev, struct rtc_time *tm)
+{
+	struct rtc_at32ap700x *rtc = dev_get_drvdata(dev);
+	unsigned long now;
+	int ret;
+
+	ret = rtc_tm_to_time(tm, &now);
+	if (ret == 0)
+		rtc_writel(rtc, VAL, now);
+
+	return ret;
+}
+
+static int at32_rtc_readalarm(struct device *dev, struct rtc_wkalrm *alrm)
+{
+	struct rtc_at32ap700x *rtc = dev_get_drvdata(dev);
+
+	spin_lock_irq(&rtc->lock);
+	rtc_time_to_tm(rtc->alarm_time, &alrm->time);
+	alrm->enabled = rtc_readl(rtc, IMR) & RTC_BIT(IMR_TOPI) ? 1 : 0;
+	alrm->pending = rtc_readl(rtc, ISR) & RTC_BIT(ISR_TOPI) ? 1 : 0;
+	spin_unlock_irq(&rtc->lock);
+
+	return 0;
+}
+
+static int at32_rtc_setalarm(struct device *dev, struct rtc_wkalrm *alrm)
+{
+	struct rtc_at32ap700x *rtc = dev_get_drvdata(dev);
+	unsigned long rtc_unix_time;
+	unsigned long alarm_unix_time;
+	int ret;
+
+	rtc_unix_time = rtc_readl(rtc, VAL);
+
+	ret = rtc_tm_to_time(&alrm->time, &alarm_unix_time);
+	if (ret)
+		return ret;
+
+	if (alarm_unix_time < rtc_unix_time)
+		return -EINVAL;
+
+	spin_lock_irq(&rtc->lock);
+	rtc->alarm_time = alarm_unix_time;
+	rtc_writel(rtc, TOP, rtc->alarm_time);
+	if (alrm->enabled)
+		rtc_writel(rtc, CTRL, rtc_readl(rtc, CTRL)
+				| RTC_BIT(CTRL_TOPEN));
+	else
+		rtc_writel(rtc, CTRL, rtc_readl(rtc, CTRL)
+				& ~RTC_BIT(CTRL_TOPEN));
+	spin_unlock_irq(&rtc->lock);
+
+	return ret;
+}
+
+static int at32_rtc_alarm_irq_enable(struct device *dev, unsigned int enabled)
+{
+	struct rtc_at32ap700x *rtc = dev_get_drvdata(dev);
+	int ret = 0;
+
+	spin_lock_irq(&rtc->lock);
+
+	if (enabled) {
+		if (rtc_readl(rtc, VAL) > rtc->alarm_time) {
+			ret = -EINVAL;
+			goto out;
+		}
+		rtc_writel(rtc, CTRL, rtc_readl(rtc, CTRL)
+				| RTC_BIT(CTRL_TOPEN));
+		rtc_writel(rtc, ICR, RTC_BIT(ICR_TOPI));
+		rtc_writel(rtc, IER, RTC_BIT(IER_TOPI));
+	} else {
+		rtc_writel(rtc, CTRL, rtc_readl(rtc, CTRL)
+				& ~RTC_BIT(CTRL_TOPEN));
+		rtc_writel(rtc, IDR, RTC_BIT(IDR_TOPI));
+		rtc_writel(rtc, ICR, RTC_BIT(ICR_TOPI));
+	}
+out:
+	spin_unlock_irq(&rtc->lock);
+
+	return ret;
+}
+
+static irqreturn_t at32_rtc_interrupt(int irq, void *dev_id)
+{
+	struct rtc_at32ap700x *rtc = (struct rtc_at32ap700x *)dev_id;
+	unsigned long isr = rtc_readl(rtc, ISR);
+	unsigned long events = 0;
+	int ret = IRQ_NONE;
+
+	spin_lock(&rtc->lock);
+
+	if (isr & RTC_BIT(ISR_TOPI)) {
+		rtc_writel(rtc, ICR, RTC_BIT(ICR_TOPI));
+		rtc_writel(rtc, IDR, RTC_BIT(IDR_TOPI));
+		rtc_writel(rtc, CTRL, rtc_readl(rtc, CTRL)
+				& ~RTC_BIT(CTRL_TOPEN));
+		rtc_writel(rtc, VAL, rtc->alarm_time);
+		events = RTC_AF | RTC_IRQF;
+		rtc_update_irq(rtc->rtc, 1, events);
+		ret = IRQ_HANDLED;
+	}
+
+	spin_unlock(&rtc->lock);
+
+	return ret;
+}
+
+static struct rtc_class_ops at32_rtc_ops = {
+	.read_time	= at32_rtc_readtime,
+	.set_time	= at32_rtc_settime,
+	.read_alarm	= at32_rtc_readalarm,
+	.set_alarm	= at32_rtc_setalarm,
+	.alarm_irq_enable = at32_rtc_alarm_irq_enable,
+};
+
+static int __init at32_rtc_probe(struct platform_device *pdev)
+{
+	struct resource	*regs;
+	struct rtc_at32ap700x *rtc;
+	int irq;
+	int ret;
+
+	rtc = devm_kzalloc(&pdev->dev, sizeof(struct rtc_at32ap700x),
+			   GFP_KERNEL);
+	if (!rtc)
+		return -ENOMEM;
+
+	regs = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	if (!regs) {
+		dev_dbg(&pdev->dev, "no mmio resource defined\n");
+		return -ENXIO;
+	}
+
+	irq = platform_get_irq(pdev, 0);
+	if (irq <= 0) {
+		dev_dbg(&pdev->dev, "could not get irq\n");
+		return -ENXIO;
+	}
+
+	rtc->irq = irq;
+	rtc->regs = devm_ioremap(&pdev->dev, regs->start, resource_size(regs));
+	if (!rtc->regs) {
+		dev_dbg(&pdev->dev, "could not map I/O memory\n");
+		return -ENOMEM;
+	}
+	spin_lock_init(&rtc->lock);
+
+	/*
+	 * Maybe init RTC: count from zero at 1 Hz, disable wrap irq.
+	 *
+	 * Do not reset VAL register, as it can hold an old time
+	 * from last JTAG reset.
+	 */
+	if (!(rtc_readl(rtc, CTRL) & RTC_BIT(CTRL_EN))) {
+		rtc_writel(rtc, CTRL, RTC_BIT(CTRL_PCLR));
+		rtc_writel(rtc, IDR, RTC_BIT(IDR_TOPI));
+		rtc_writel(rtc, CTRL, RTC_BF(CTRL_PSEL, 0xe)
+				| RTC_BIT(CTRL_EN));
+	}
+
+	ret = devm_request_irq(&pdev->dev, irq, at32_rtc_interrupt, IRQF_SHARED,
+				"rtc", rtc);
+	if (ret) {
+		dev_dbg(&pdev->dev, "could not request irq %d\n", irq);
+		return ret;
+	}
+
+	platform_set_drvdata(pdev, rtc);
+
+	rtc->rtc = devm_rtc_device_register(&pdev->dev, pdev->name,
+				&at32_rtc_ops, THIS_MODULE);
+	if (IS_ERR(rtc->rtc)) {
+		dev_dbg(&pdev->dev, "could not register rtc device\n");
+		return PTR_ERR(rtc->rtc);
+	}
+
+	device_init_wakeup(&pdev->dev, 1);
+
+	dev_info(&pdev->dev, "Atmel RTC for AT32AP700x at %08lx irq %ld\n",
+			(unsigned long)rtc->regs, rtc->irq);
+
+	return 0;
+}
+
+static int __exit at32_rtc_remove(struct platform_device *pdev)
+{
+	device_init_wakeup(&pdev->dev, 0);
+
+	return 0;
+}
+
+MODULE_ALIAS("platform:at32ap700x_rtc");
+
+static struct platform_driver at32_rtc_driver = {
+	.remove		= __exit_p(at32_rtc_remove),
+	.driver		= {
+		.name	= "at32ap700x_rtc",
+	},
+};
+
+module_platform_driver_probe(at32_rtc_driver, at32_rtc_probe);
+
+MODULE_AUTHOR("Hans-Christian Egtvedt <hcegtvedt@atmel.com>");
+MODULE_DESCRIPTION("Real time clock for AVR32 AT32AP700x");
+MODULE_LICENSE("GPL");