unicore32: move rtc-puv3.c to drivers/rtc directory

The patch moves rtc driver for PKUnity-v3 SoC from arch/unicore32/kernel/
to drivers/rtc/, with renaming it to rtc-puv3.c.
Also, Kconfig, Makefile, and MAINTAINERS are modified correspondingly.

Signed-off-by: Guan Xuetao <gxt@mprc.pku.edu.cn>
Acked-by: Arnd Bergmann <arnd@arndb.de>
diff --git a/drivers/rtc/rtc-puv3.c b/drivers/rtc/rtc-puv3.c
new file mode 100644
index 0000000..46f14b8
--- /dev/null
+++ b/drivers/rtc/rtc-puv3.c
@@ -0,0 +1,359 @@
+/*
+ * RTC driver code specific to PKUnity SoC and UniCore ISA
+ *
+ *	Maintained by GUAN Xue-tao <gxt@mprc.pku.edu.cn>
+ *	Copyright (C) 2001-2010 Guan Xuetao
+ *
+ * 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/fs.h>
+#include <linux/string.h>
+#include <linux/init.h>
+#include <linux/platform_device.h>
+#include <linux/interrupt.h>
+#include <linux/rtc.h>
+#include <linux/bcd.h>
+#include <linux/clk.h>
+#include <linux/log2.h>
+#include <linux/slab.h>
+#include <linux/uaccess.h>
+#include <linux/io.h>
+
+#include <asm/irq.h>
+#include <mach/hardware.h>
+
+static struct resource *puv3_rtc_mem;
+
+static int puv3_rtc_alarmno = IRQ_RTCAlarm;
+static int puv3_rtc_tickno  = IRQ_RTC;
+
+static DEFINE_SPINLOCK(puv3_rtc_pie_lock);
+
+/* IRQ Handlers */
+static irqreturn_t puv3_rtc_alarmirq(int irq, void *id)
+{
+	struct rtc_device *rdev = id;
+
+	writel(readl(RTC_RTSR) | RTC_RTSR_AL, RTC_RTSR);
+	rtc_update_irq(rdev, 1, RTC_AF | RTC_IRQF);
+	return IRQ_HANDLED;
+}
+
+static irqreturn_t puv3_rtc_tickirq(int irq, void *id)
+{
+	struct rtc_device *rdev = id;
+
+	writel(readl(RTC_RTSR) | RTC_RTSR_HZ, RTC_RTSR);
+	rtc_update_irq(rdev, 1, RTC_PF | RTC_IRQF);
+	return IRQ_HANDLED;
+}
+
+/* Update control registers */
+static void puv3_rtc_setaie(int to)
+{
+	unsigned int tmp;
+
+	pr_debug("%s: aie=%d\n", __func__, to);
+
+	tmp = readl(RTC_RTSR) & ~RTC_RTSR_ALE;
+
+	if (to)
+		tmp |= RTC_RTSR_ALE;
+
+	writel(tmp, RTC_RTSR);
+}
+
+static int puv3_rtc_setpie(struct device *dev, int enabled)
+{
+	unsigned int tmp;
+
+	pr_debug("%s: pie=%d\n", __func__, enabled);
+
+	spin_lock_irq(&puv3_rtc_pie_lock);
+	tmp = readl(RTC_RTSR) & ~RTC_RTSR_HZE;
+
+	if (enabled)
+		tmp |= RTC_RTSR_HZE;
+
+	writel(tmp, RTC_RTSR);
+	spin_unlock_irq(&puv3_rtc_pie_lock);
+
+	return 0;
+}
+
+/* Time read/write */
+static int puv3_rtc_gettime(struct device *dev, struct rtc_time *rtc_tm)
+{
+	rtc_time_to_tm(readl(RTC_RCNR), rtc_tm);
+
+	pr_debug("read time %02x.%02x.%02x %02x/%02x/%02x\n",
+		 rtc_tm->tm_year, rtc_tm->tm_mon, rtc_tm->tm_mday,
+		 rtc_tm->tm_hour, rtc_tm->tm_min, rtc_tm->tm_sec);
+
+	return 0;
+}
+
+static int puv3_rtc_settime(struct device *dev, struct rtc_time *tm)
+{
+	unsigned long rtc_count = 0;
+
+	pr_debug("set time %02d.%02d.%02d %02d/%02d/%02d\n",
+		 tm->tm_year, tm->tm_mon, tm->tm_mday,
+		 tm->tm_hour, tm->tm_min, tm->tm_sec);
+
+	rtc_tm_to_time(tm, &rtc_count);
+	writel(rtc_count, RTC_RCNR);
+
+	return 0;
+}
+
+static int puv3_rtc_getalarm(struct device *dev, struct rtc_wkalrm *alrm)
+{
+	struct rtc_time *alm_tm = &alrm->time;
+
+	rtc_time_to_tm(readl(RTC_RTAR), alm_tm);
+
+	alrm->enabled = readl(RTC_RTSR) & RTC_RTSR_ALE;
+
+	pr_debug("read alarm %02x %02x.%02x.%02x %02x/%02x/%02x\n",
+		 alrm->enabled,
+		 alm_tm->tm_year, alm_tm->tm_mon, alm_tm->tm_mday,
+		 alm_tm->tm_hour, alm_tm->tm_min, alm_tm->tm_sec);
+
+	return 0;
+}
+
+static int puv3_rtc_setalarm(struct device *dev, struct rtc_wkalrm *alrm)
+{
+	struct rtc_time *tm = &alrm->time;
+	unsigned long rtcalarm_count = 0;
+
+	pr_debug("puv3_rtc_setalarm: %d, %02x/%02x/%02x %02x.%02x.%02x\n",
+		 alrm->enabled,
+		 tm->tm_mday & 0xff, tm->tm_mon & 0xff, tm->tm_year & 0xff,
+		 tm->tm_hour & 0xff, tm->tm_min & 0xff, tm->tm_sec);
+
+	rtc_tm_to_time(tm, &rtcalarm_count);
+	writel(rtcalarm_count, RTC_RTAR);
+
+	puv3_rtc_setaie(alrm->enabled);
+
+	if (alrm->enabled)
+		enable_irq_wake(puv3_rtc_alarmno);
+	else
+		disable_irq_wake(puv3_rtc_alarmno);
+
+	return 0;
+}
+
+static int puv3_rtc_proc(struct device *dev, struct seq_file *seq)
+{
+	seq_printf(seq, "periodic_IRQ\t: %s\n",
+		     (readl(RTC_RTSR) & RTC_RTSR_HZE) ? "yes" : "no");
+	return 0;
+}
+
+static int puv3_rtc_open(struct device *dev)
+{
+	struct platform_device *pdev = to_platform_device(dev);
+	struct rtc_device *rtc_dev = platform_get_drvdata(pdev);
+	int ret;
+
+	ret = request_irq(puv3_rtc_alarmno, puv3_rtc_alarmirq,
+			  IRQF_DISABLED,  "pkunity-rtc alarm", rtc_dev);
+
+	if (ret) {
+		dev_err(dev, "IRQ%d error %d\n", puv3_rtc_alarmno, ret);
+		return ret;
+	}
+
+	ret = request_irq(puv3_rtc_tickno, puv3_rtc_tickirq,
+			  IRQF_DISABLED,  "pkunity-rtc tick", rtc_dev);
+
+	if (ret) {
+		dev_err(dev, "IRQ%d error %d\n", puv3_rtc_tickno, ret);
+		goto tick_err;
+	}
+
+	return ret;
+
+ tick_err:
+	free_irq(puv3_rtc_alarmno, rtc_dev);
+	return ret;
+}
+
+static void puv3_rtc_release(struct device *dev)
+{
+	struct platform_device *pdev = to_platform_device(dev);
+	struct rtc_device *rtc_dev = platform_get_drvdata(pdev);
+
+	/* do not clear AIE here, it may be needed for wake */
+	puv3_rtc_setpie(dev, 0);
+	free_irq(puv3_rtc_alarmno, rtc_dev);
+	free_irq(puv3_rtc_tickno, rtc_dev);
+}
+
+static const struct rtc_class_ops puv3_rtcops = {
+	.open		= puv3_rtc_open,
+	.release	= puv3_rtc_release,
+	.read_time	= puv3_rtc_gettime,
+	.set_time	= puv3_rtc_settime,
+	.read_alarm	= puv3_rtc_getalarm,
+	.set_alarm	= puv3_rtc_setalarm,
+	.proc	        = puv3_rtc_proc,
+};
+
+static void puv3_rtc_enable(struct platform_device *pdev, int en)
+{
+	if (!en) {
+		writel(readl(RTC_RTSR) & ~RTC_RTSR_HZE, RTC_RTSR);
+	} else {
+		/* re-enable the device, and check it is ok */
+		if ((readl(RTC_RTSR) & RTC_RTSR_HZE) == 0) {
+			dev_info(&pdev->dev, "rtc disabled, re-enabling\n");
+			writel(readl(RTC_RTSR) | RTC_RTSR_HZE, RTC_RTSR);
+		}
+	}
+}
+
+static int puv3_rtc_remove(struct platform_device *dev)
+{
+	struct rtc_device *rtc = platform_get_drvdata(dev);
+
+	platform_set_drvdata(dev, NULL);
+	rtc_device_unregister(rtc);
+
+	puv3_rtc_setpie(&dev->dev, 0);
+	puv3_rtc_setaie(0);
+
+	release_resource(puv3_rtc_mem);
+	kfree(puv3_rtc_mem);
+
+	return 0;
+}
+
+static int puv3_rtc_probe(struct platform_device *pdev)
+{
+	struct rtc_device *rtc;
+	struct resource *res;
+	int ret;
+
+	pr_debug("%s: probe=%p\n", __func__, pdev);
+
+	/* find the IRQs */
+	puv3_rtc_tickno = platform_get_irq(pdev, 1);
+	if (puv3_rtc_tickno < 0) {
+		dev_err(&pdev->dev, "no irq for rtc tick\n");
+		return -ENOENT;
+	}
+
+	puv3_rtc_alarmno = platform_get_irq(pdev, 0);
+	if (puv3_rtc_alarmno < 0) {
+		dev_err(&pdev->dev, "no irq for alarm\n");
+		return -ENOENT;
+	}
+
+	pr_debug("PKUnity_rtc: tick irq %d, alarm irq %d\n",
+		 puv3_rtc_tickno, puv3_rtc_alarmno);
+
+	/* get the memory region */
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	if (res == NULL) {
+		dev_err(&pdev->dev, "failed to get memory region resource\n");
+		return -ENOENT;
+	}
+
+	puv3_rtc_mem = request_mem_region(res->start,
+					 res->end-res->start+1,
+					 pdev->name);
+
+	if (puv3_rtc_mem == NULL) {
+		dev_err(&pdev->dev, "failed to reserve memory region\n");
+		ret = -ENOENT;
+		goto err_nores;
+	}
+
+	puv3_rtc_enable(pdev, 1);
+
+	/* register RTC and exit */
+	rtc = rtc_device_register("pkunity", &pdev->dev, &puv3_rtcops,
+				  THIS_MODULE);
+
+	if (IS_ERR(rtc)) {
+		dev_err(&pdev->dev, "cannot attach rtc\n");
+		ret = PTR_ERR(rtc);
+		goto err_nortc;
+	}
+
+	/* platform setup code should have handled this; sigh */
+	if (!device_can_wakeup(&pdev->dev))
+		device_init_wakeup(&pdev->dev, 1);
+
+	platform_set_drvdata(pdev, rtc);
+	return 0;
+
+ err_nortc:
+	puv3_rtc_enable(pdev, 0);
+	release_resource(puv3_rtc_mem);
+
+ err_nores:
+	return ret;
+}
+
+#ifdef CONFIG_PM
+
+static int ticnt_save;
+
+static int puv3_rtc_suspend(struct platform_device *pdev, pm_message_t state)
+{
+	/* save RTAR for anyone using periodic interrupts */
+	ticnt_save = readl(RTC_RTAR);
+	puv3_rtc_enable(pdev, 0);
+	return 0;
+}
+
+static int puv3_rtc_resume(struct platform_device *pdev)
+{
+	puv3_rtc_enable(pdev, 1);
+	writel(ticnt_save, RTC_RTAR);
+	return 0;
+}
+#else
+#define puv3_rtc_suspend NULL
+#define puv3_rtc_resume  NULL
+#endif
+
+static struct platform_driver puv3_rtcdrv = {
+	.probe		= puv3_rtc_probe,
+	.remove		= __devexit_p(puv3_rtc_remove),
+	.suspend	= puv3_rtc_suspend,
+	.resume		= puv3_rtc_resume,
+	.driver		= {
+		.name	= "PKUnity-v3-RTC",
+		.owner	= THIS_MODULE,
+	}
+};
+
+static char __initdata banner[] = "PKUnity-v3 RTC, (c) 2009 PKUnity Co.\n";
+
+static int __init puv3_rtc_init(void)
+{
+	printk(banner);
+	return platform_driver_register(&puv3_rtcdrv);
+}
+
+static void __exit puv3_rtc_exit(void)
+{
+	platform_driver_unregister(&puv3_rtcdrv);
+}
+
+module_init(puv3_rtc_init);
+module_exit(puv3_rtc_exit);
+
+MODULE_DESCRIPTION("RTC Driver for the PKUnity v3 chip");
+MODULE_AUTHOR("Hu Dongliang");
+MODULE_LICENSE("GPL v2");