ARM: NUC900: add RTC driver support for nuc910 and nuc920

Signed-off-by: Wan ZongShun <mcuos.com@gmail.com>
Cc: Alessandro Zummo <a.zummo@towertech.it>
Cc: Hu Ruihuan <specter118@gmail.com>
Cc: Russell King <rmk@arm.linux.org.uk>
Cc: "jack wang" <jack_wang@usish.com>
Cc: David Brownell <david-b@pacbell.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

3 files changed, 349 insertions, 0 deletions

diff --git a/drivers/rtc/Kconfig b/drivers/rtc/Kconfig
index 40c168bf6984..8167e9e6827a 100644
--- a/drivers/rtc/Kconfig
+++ b/drivers/rtc/Kconfig
@@ -601,6 +601,12 @@ config RTC_DRV_AB3100
           Select this to enable the ST-Ericsson AB3100 Mixed Signal IC RTC
           support. This chip contains a battery- and capacitor-backed RTC.
 
+config RTC_DRV_NUC900
+        tristate "NUC910/NUC920 RTC driver"
+        depends on RTC_CLASS && ARCH_W90X900
+        help
+          If you say yes here you get support for the RTC subsystem of the
+          NUC910/NUC920 used in embedded systems.
 
 comment "on-CPU RTC drivers"
 
diff --git a/drivers/rtc/Makefile b/drivers/rtc/Makefile
index 52f5f3c3b8e0..e5160fddc446 100644
--- a/drivers/rtc/Makefile
+++ b/drivers/rtc/Makefile
@@ -56,6 +56,7 @@ obj-$(CONFIG_RTC_DRV_MAX6902)	+= rtc-max6902.o
 obj-$(CONFIG_RTC_DRV_MC13783)   += rtc-mc13783.o
 obj-$(CONFIG_RTC_DRV_MSM6242)   += rtc-msm6242.o
 obj-$(CONFIG_RTC_DRV_MV)        += rtc-mv.o
+obj-$(CONFIG_RTC_DRV_NUC900)    += rtc-nuc900.o
 obj-$(CONFIG_RTC_DRV_OMAP)      += rtc-omap.o
 obj-$(CONFIG_RTC_DRV_PCAP)      += rtc-pcap.o
 obj-$(CONFIG_RTC_DRV_PCF8563)   += rtc-pcf8563.o
diff --git a/drivers/rtc/rtc-nuc900.c b/drivers/rtc/rtc-nuc900.c
new file mode 100644
index 000000000000..bf59c9c586b2
--- /dev/null
+++ b/drivers/rtc/rtc-nuc900.c
@@ -0,0 +1,342 @@
+/*
+ * Copyright (c) 2008-2009 Nuvoton technology corporation.
+ *
+ * Wan ZongShun <mcuos.com@gmail.com>
+ *
+ * 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;version 2 of the License.
+ *
+ */
+
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/platform_device.h>
+#include <linux/rtc.h>
+#include <linux/delay.h>
+#include <linux/io.h>
+#include <linux/bcd.h>
+
+/* RTC Control Registers */
+#define REG_RTC_INIR            0x00
+#define REG_RTC_AER             0x04
+#define REG_RTC_FCR             0x08
+#define REG_RTC_TLR             0x0C
+#define REG_RTC_CLR             0x10
+#define REG_RTC_TSSR            0x14
+#define REG_RTC_DWR             0x18
+#define REG_RTC_TAR             0x1C
+#define REG_RTC_CAR             0x20
+#define REG_RTC_LIR             0x24
+#define REG_RTC_RIER            0x28
+#define REG_RTC_RIIR            0x2C
+#define REG_RTC_TTR             0x30
+
+#define RTCSET                  0x01
+#define AERRWENB                0x10000
+#define INIRRESET               0xa5eb1357
+#define AERPOWERON              0xA965
+#define AERPOWEROFF             0x0000
+#define LEAPYEAR                0x0001
+#define TICKENB                 0x80
+#define TICKINTENB              0x0002
+#define ALARMINTENB             0x0001
+#define MODE24                  0x0001
+
+struct nuc900_rtc {
+        int                     irq_num;
+        void __iomem            *rtc_reg;
+        struct rtc_device       *rtcdev;
+};
+
+struct nuc900_bcd_time {
+        int bcd_sec;
+        int bcd_min;
+        int bcd_hour;
+        int bcd_mday;
+        int bcd_mon;
+        int bcd_year;
+};
+
+static irqreturn_t nuc900_rtc_interrupt(int irq, void *_rtc)
+{
+        struct nuc900_rtc *rtc = _rtc;
+        unsigned long events = 0, rtc_irq;
+
+        rtc_irq = __raw_readl(rtc->rtc_reg + REG_RTC_RIIR);
+
+        if (rtc_irq & ALARMINTENB) {
+                rtc_irq &= ~ALARMINTENB;
+                __raw_writel(rtc_irq, rtc->rtc_reg + REG_RTC_RIIR);
+                events |= RTC_AF | RTC_IRQF;
+        }
+
+        if (rtc_irq & TICKINTENB) {
+                rtc_irq &= ~TICKINTENB;
+                __raw_writel(rtc_irq, rtc->rtc_reg + REG_RTC_RIIR);
+                events |= RTC_UF | RTC_IRQF;
+        }
+
+        rtc_update_irq(rtc->rtcdev, 1, events);
+
+        return IRQ_HANDLED;
+}
+
+static int *check_rtc_access_enable(struct nuc900_rtc *nuc900_rtc)
+{
+        unsigned int i;
+        __raw_writel(INIRRESET, nuc900_rtc->rtc_reg + REG_RTC_INIR);
+
+        mdelay(10);
+
+        __raw_writel(AERPOWERON, nuc900_rtc->rtc_reg + REG_RTC_AER);
+
+        for (i = 0; i < 1000; i++) {
+                if (__raw_readl(nuc900_rtc->rtc_reg + REG_RTC_AER) & AERRWENB)
+                        return 0;
+        }
+
+        if ((__raw_readl(nuc900_rtc->rtc_reg + REG_RTC_AER) & AERRWENB) == 0x0)
+                return ERR_PTR(-ENODEV);
+
+        return ERR_PTR(-EPERM);
+}
+
+static void nuc900_rtc_bcd2bin(unsigned int timereg,
+                                unsigned int calreg, struct rtc_time *tm)
+{
+        tm->tm_mday     = bcd2bin(calreg >> 0);
+        tm->tm_mon      = bcd2bin(calreg >> 8);
+        tm->tm_year     = bcd2bin(calreg >> 16) + 100;
+
+        tm->tm_sec      = bcd2bin(timereg >> 0);
+        tm->tm_min      = bcd2bin(timereg >> 8);
+        tm->tm_hour     = bcd2bin(timereg >> 16);
+
+        rtc_valid_tm(tm);
+}
+
+static void nuc900_rtc_bin2bcd(struct rtc_time *settm,
+                                                struct nuc900_bcd_time *gettm)
+{
+        gettm->bcd_mday = bin2bcd(settm->tm_mday) << 0;
+        gettm->bcd_mon  = bin2bcd(settm->tm_mon) << 8;
+        gettm->bcd_year = bin2bcd(settm->tm_year - 100) << 16;
+
+        gettm->bcd_sec  = bin2bcd(settm->tm_sec) << 0;
+        gettm->bcd_min  = bin2bcd(settm->tm_min) << 8;
+        gettm->bcd_hour = bin2bcd(settm->tm_hour) << 16;
+}
+
+static int nuc900_update_irq_enable(struct device *dev, unsigned int enabled)
+{
+        struct nuc900_rtc *rtc = dev_get_drvdata(dev);
+
+        if (enabled)
+                __raw_writel(__raw_readl(rtc->rtc_reg + REG_RTC_RIER)|
+                                (TICKINTENB), rtc->rtc_reg + REG_RTC_RIER);
+        else
+                __raw_writel(__raw_readl(rtc->rtc_reg + REG_RTC_RIER)&
+                                (~TICKINTENB), rtc->rtc_reg + REG_RTC_RIER);
+
+        return 0;
+}
+
+static int nuc900_alarm_irq_enable(struct device *dev, unsigned int enabled)
+{
+        struct nuc900_rtc *rtc = dev_get_drvdata(dev);
+
+        if (enabled)
+                __raw_writel(__raw_readl(rtc->rtc_reg + REG_RTC_RIER)|
+                                (ALARMINTENB), rtc->rtc_reg + REG_RTC_RIER);
+        else
+                __raw_writel(__raw_readl(rtc->rtc_reg + REG_RTC_RIER)&
+                                (~ALARMINTENB), rtc->rtc_reg + REG_RTC_RIER);
+
+        return 0;
+}
+
+static int nuc900_rtc_read_time(struct device *dev, struct rtc_time *tm)
+{
+        struct nuc900_rtc *rtc = dev_get_drvdata(dev);
+        unsigned int timeval, clrval;
+
+        timeval = __raw_readl(rtc->rtc_reg + REG_RTC_TLR);
+        clrval  = __raw_readl(rtc->rtc_reg + REG_RTC_CLR);
+
+        nuc900_rtc_bcd2bin(timeval, clrval, tm);
+
+        return 0;
+}
+
+static int nuc900_rtc_set_time(struct device *dev, struct rtc_time *tm)
+{
+        struct nuc900_rtc *rtc = dev_get_drvdata(dev);
+        struct nuc900_bcd_time gettm;
+        unsigned long val;
+        int *err;
+
+        nuc900_rtc_bin2bcd(tm, &gettm);
+
+        err = check_rtc_access_enable(rtc);
+        if (IS_ERR(err))
+                return PTR_ERR(err);
+
+        val = gettm.bcd_mday | gettm.bcd_mon | gettm.bcd_year;
+        __raw_writel(val, rtc->rtc_reg + REG_RTC_CLR);
+
+        val = gettm.bcd_sec | gettm.bcd_min | gettm.bcd_hour;
+        __raw_writel(val, rtc->rtc_reg + REG_RTC_TLR);
+
+        return 0;
+}
+
+static int nuc900_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alrm)
+{
+        struct nuc900_rtc *rtc = dev_get_drvdata(dev);
+        unsigned int timeval, carval;
+
+        timeval = __raw_readl(rtc->rtc_reg + REG_RTC_TAR);
+        carval  = __raw_readl(rtc->rtc_reg + REG_RTC_CAR);
+
+        nuc900_rtc_bcd2bin(timeval, carval, &alrm->time);
+
+        return 0;
+}
+
+static int nuc900_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm)
+{
+        struct nuc900_rtc *rtc = dev_get_drvdata(dev);
+        struct nuc900_bcd_time tm;
+        unsigned long val;
+        int *err;
+
+        nuc900_rtc_bin2bcd(&alrm->time, &tm);
+
+        err = check_rtc_access_enable(rtc);
+        if (IS_ERR(err))
+                return PTR_ERR(err);
+
+        val = tm.bcd_mday | tm.bcd_mon | tm.bcd_year;
+        __raw_writel(val, rtc->rtc_reg + REG_RTC_CAR);
+
+        val = tm.bcd_sec | tm.bcd_min | tm.bcd_hour;
+        __raw_writel(val, rtc->rtc_reg + REG_RTC_TAR);
+
+        return 0;
+}
+
+static struct rtc_class_ops nuc900_rtc_ops = {
+        .read_time = nuc900_rtc_read_time,
+        .set_time = nuc900_rtc_set_time,
+        .read_alarm = nuc900_rtc_read_alarm,
+        .set_alarm = nuc900_rtc_set_alarm,
+        .alarm_irq_enable = nuc900_alarm_irq_enable,
+        .update_irq_enable = nuc900_update_irq_enable,
+};
+
+static int __devinit nuc900_rtc_probe(struct platform_device *pdev)
+{
+        struct resource *res;
+        struct nuc900_rtc *nuc900_rtc;
+        int err = 0;
+
+        nuc900_rtc = kzalloc(sizeof(struct nuc900_rtc), GFP_KERNEL);
+        if (!nuc900_rtc) {
+                dev_err(&pdev->dev, "kzalloc nuc900_rtc failed\n");
+                return -ENOMEM;
+        }
+        res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+        if (!res) {
+                dev_err(&pdev->dev, "platform_get_resource failed\n");
+                err = -ENXIO;
+                goto fail1;
+        }
+
+        if (!request_mem_region(res->start, resource_size(res),
+                                pdev->name)) {
+                dev_err(&pdev->dev, "request_mem_region failed\n");
+                err = -EBUSY;
+                goto fail1;
+        }
+
+        nuc900_rtc->rtc_reg = ioremap(res->start, resource_size(res));
+        if (!nuc900_rtc->rtc_reg) {
+                dev_err(&pdev->dev, "ioremap rtc_reg failed\n");
+                err = -ENOMEM;
+                goto fail2;
+        }
+
+        nuc900_rtc->irq_num = platform_get_irq(pdev, 0);
+        if (request_irq(nuc900_rtc->irq_num, nuc900_rtc_interrupt,
+                                IRQF_DISABLED, "nuc900rtc", nuc900_rtc)) {
+                dev_err(&pdev->dev, "NUC900 RTC request irq failed\n");
+                err = -EBUSY;
+                goto fail3;
+        }
+
+        nuc900_rtc->rtcdev = rtc_device_register(pdev->name, &pdev->dev,
+                                                &nuc900_rtc_ops, THIS_MODULE);
+        if (IS_ERR(nuc900_rtc->rtcdev)) {
+                dev_err(&pdev->dev, "rtc device register faild\n");
+                err = PTR_ERR(nuc900_rtc->rtcdev);
+                goto fail4;
+        }
+
+        platform_set_drvdata(pdev, nuc900_rtc);
+        __raw_writel(__raw_readl(nuc900_rtc->rtc_reg + REG_RTC_TSSR) | MODE24,
+                                        nuc900_rtc->rtc_reg + REG_RTC_TSSR);
+
+        return 0;
+
+fail4:  free_irq(nuc900_rtc->irq_num, nuc900_rtc);
+fail3:  iounmap(nuc900_rtc->rtc_reg);
+fail2:  release_mem_region(res->start, resource_size(res));
+fail1:  kfree(nuc900_rtc);
+        return err;
+}
+
+static int __devexit nuc900_rtc_remove(struct platform_device *pdev)
+{
+        struct nuc900_rtc *nuc900_rtc = platform_get_drvdata(pdev);
+        struct resource *res;
+
+        rtc_device_unregister(nuc900_rtc->rtcdev);
+        free_irq(nuc900_rtc->irq_num, nuc900_rtc);
+        iounmap(nuc900_rtc->rtc_reg);
+
+        res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+        release_mem_region(res->start, resource_size(res));
+
+        kfree(nuc900_rtc);
+
+        platform_set_drvdata(pdev, NULL);
+
+        return 0;
+}
+
+static struct platform_driver nuc900_rtc_driver = {
+        .remove         = __devexit_p(nuc900_rtc_remove),
+        .driver         = {
+                .name   = "nuc900-rtc",
+                .owner  = THIS_MODULE,
+        },
+};
+
+static int __init nuc900_rtc_init(void)
+{
+        return platform_driver_probe(&nuc900_rtc_driver, nuc900_rtc_probe);
+}
+
+static void __exit nuc900_rtc_exit(void)
+{
+        platform_driver_unregister(&nuc900_rtc_driver);
+}
+
+module_init(nuc900_rtc_init);
+module_exit(nuc900_rtc_exit);
+
+MODULE_AUTHOR("Wan ZongShun <mcuos.com@gmail.com>");
+MODULE_DESCRIPTION("nuc910/nuc920 RTC driver");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS("platform:nuc900-rtc");