--- /dev/null
+/*
+ * drivers/rtc/rtc-spear.c
+ *
+ * Copyright (C) 2010 ST Microelectronics
+ * Rajeev Kumar<rajeev-dlh.kumar@st.com>
+ *
+ * This file is licensed under the terms of the GNU General Public
+ * License version 2. This program is licensed "as is" without any
+ * warranty of any kind, whether express or implied.
+ */
+
+#include <linux/bcd.h>
+#include <linux/clk.h>
+#include <linux/delay.h>
+#include <linux/init.h>
+#include <linux/io.h>
+#include <linux/irq.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/rtc.h>
+#include <linux/slab.h>
+#include <linux/spinlock.h>
+
+/* RTC registers */
+#define TIME_REG 0x00
+#define DATE_REG 0x04
+#define ALARM_TIME_REG 0x08
+#define ALARM_DATE_REG 0x0C
+#define CTRL_REG 0x10
+#define STATUS_REG 0x14
+
+/* TIME_REG & ALARM_TIME_REG */
+#define SECONDS_UNITS (0xf<<0) /* seconds units position */
+#define SECONDS_TENS (0x7<<4) /* seconds tens position */
+#define MINUTES_UNITS (0xf<<8) /* minutes units position */
+#define MINUTES_TENS (0x7<<12) /* minutes tens position */
+#define HOURS_UNITS (0xf<<16) /* hours units position */
+#define HOURS_TENS (0x3<<20) /* hours tens position */
+
+/* DATE_REG & ALARM_DATE_REG */
+#define DAYS_UNITS (0xf<<0) /* days units position */
+#define DAYS_TENS (0x3<<4) /* days tens position */
+#define MONTHS_UNITS (0xf<<8) /* months units position */
+#define MONTHS_TENS (0x1<<12) /* months tens position */
+#define YEARS_UNITS (0xf<<16) /* years units position */
+#define YEARS_TENS (0xf<<20) /* years tens position */
+#define YEARS_HUNDREDS (0xf<<24) /* years hundereds position */
+#define YEARS_MILLENIUMS (0xf<<28) /* years millenium position */
+
+/* MASK SHIFT TIME_REG & ALARM_TIME_REG*/
+#define SECOND_SHIFT 0x00 /* seconds units */
+#define MINUTE_SHIFT 0x08 /* minutes units position */
+#define HOUR_SHIFT 0x10 /* hours units position */
+#define MDAY_SHIFT 0x00 /* Month day shift */
+#define MONTH_SHIFT 0x08 /* Month shift */
+#define YEAR_SHIFT 0x10 /* Year shift */
+
+#define SECOND_MASK 0x7F
+#define MIN_MASK 0x7F
+#define HOUR_MASK 0x3F
+#define DAY_MASK 0x3F
+#define MONTH_MASK 0x7F
+#define YEAR_MASK 0xFFFF
+
+/* date reg equal to time reg, for debug only */
+#define TIME_BYP (1<<9)
+#define INT_ENABLE (1<<31) /* interrupt enable */
+
+/* STATUS_REG */
+#define CLK_UNCONNECTED (1<<0)
+#define PEND_WR_TIME (1<<2)
+#define PEND_WR_DATE (1<<3)
+#define LOST_WR_TIME (1<<4)
+#define LOST_WR_DATE (1<<5)
+#define RTC_INT_MASK (1<<31)
+#define STATUS_BUSY (PEND_WR_TIME | PEND_WR_DATE)
+#define STATUS_FAIL (LOST_WR_TIME | LOST_WR_DATE)
+
+struct spear_rtc_config {
+ struct clk *clk;
+ spinlock_t lock;
+ void __iomem *ioaddr;
+};
+
+static inline void spear_rtc_clear_interrupt(struct spear_rtc_config *config)
+{
+ unsigned int val;
+ unsigned long flags;
+
+ spin_lock_irqsave(&config->lock, flags);
+ val = readl(config->ioaddr + STATUS_REG);
+ val |= RTC_INT_MASK;
+ writel(val, config->ioaddr + STATUS_REG);
+ spin_unlock_irqrestore(&config->lock, flags);
+}
+
+static inline void spear_rtc_enable_interrupt(struct spear_rtc_config *config)
+{
+ unsigned int val;
+
+ val = readl(config->ioaddr + CTRL_REG);
+ if (!(val & INT_ENABLE)) {
+ spear_rtc_clear_interrupt(config);
+ val |= INT_ENABLE;
+ writel(val, config->ioaddr + CTRL_REG);
+ }
+}
+
+static inline void spear_rtc_disable_interrupt(struct spear_rtc_config *config)
+{
+ unsigned int val;
+
+ val = readl(config->ioaddr + CTRL_REG);
+ if (val & INT_ENABLE) {
+ val &= ~INT_ENABLE;
+ writel(val, config->ioaddr + CTRL_REG);
+ }
+}
+
+static inline int is_write_complete(struct spear_rtc_config *config)
+{
+ int ret = 0;
+ unsigned long flags;
+
+ spin_lock_irqsave(&config->lock, flags);
+ if ((readl(config->ioaddr + STATUS_REG)) & STATUS_FAIL)
+ ret = -EIO;
+ spin_unlock_irqrestore(&config->lock, flags);
+
+ return ret;
+}
+
+static void rtc_wait_not_busy(struct spear_rtc_config *config)
+{
+ int status, count = 0;
+ unsigned long flags;
+
+ /* Assuming BUSY may stay active for 80 msec) */
+ for (count = 0; count < 80; count++) {
+ spin_lock_irqsave(&config->lock, flags);
+ status = readl(config->ioaddr + STATUS_REG);
+ spin_unlock_irqrestore(&config->lock, flags);
+ if ((status & STATUS_BUSY) == 0)
+ break;
+ /* check status busy, after each msec */
+ msleep(1);
+ }
+}
+
+static irqreturn_t spear_rtc_irq(int irq, void *dev_id)
+{
+ struct rtc_device *rtc = (struct rtc_device *)dev_id;
+ struct spear_rtc_config *config = dev_get_drvdata(&rtc->dev);
+ unsigned long flags, events = 0;
+ unsigned int irq_data;
+
+ spin_lock_irqsave(&config->lock, flags);
+ irq_data = readl(config->ioaddr + STATUS_REG);
+ spin_unlock_irqrestore(&config->lock, flags);
+
+ if ((irq_data & RTC_INT_MASK)) {
+ spear_rtc_clear_interrupt(config);
+ events = RTC_IRQF | RTC_AF;
+ rtc_update_irq(rtc, 1, events);
+ return IRQ_HANDLED;
+ } else
+ return IRQ_NONE;
+
+}
+
+static int tm2bcd(struct rtc_time *tm)
+{
+ if (rtc_valid_tm(tm) != 0)
+ return -EINVAL;
+ tm->tm_sec = bin2bcd(tm->tm_sec);
+ tm->tm_min = bin2bcd(tm->tm_min);
+ tm->tm_hour = bin2bcd(tm->tm_hour);
+ tm->tm_mday = bin2bcd(tm->tm_mday);
+ tm->tm_mon = bin2bcd(tm->tm_mon + 1);
+ tm->tm_year = bin2bcd(tm->tm_year);
+
+ return 0;
+}
+
+static void bcd2tm(struct rtc_time *tm)
+{
+ tm->tm_sec = bcd2bin(tm->tm_sec);
+ tm->tm_min = bcd2bin(tm->tm_min);
+ tm->tm_hour = bcd2bin(tm->tm_hour);
+ tm->tm_mday = bcd2bin(tm->tm_mday);
+ tm->tm_mon = bcd2bin(tm->tm_mon) - 1;
+ /* epoch == 1900 */
+ tm->tm_year = bcd2bin(tm->tm_year);
+}
+
+/*
+ * spear_rtc_read_time - set the time
+ * @dev: rtc device in use
+ * @tm: holds date and time
+ *
+ * This function read time and date. On success it will return 0
+ * otherwise -ve error is returned.
+ */
+static int spear_rtc_read_time(struct device *dev, struct rtc_time *tm)
+{
+ struct platform_device *pdev = to_platform_device(dev);
+ struct rtc_device *rtc = platform_get_drvdata(pdev);
+ struct spear_rtc_config *config = dev_get_drvdata(&rtc->dev);
+ unsigned int time, date;
+
+ /* we don't report wday/yday/isdst ... */
+ rtc_wait_not_busy(config);
+
+ time = readl(config->ioaddr + TIME_REG);
+ date = readl(config->ioaddr + DATE_REG);
+ tm->tm_sec = (time >> SECOND_SHIFT) & SECOND_MASK;
+ tm->tm_min = (time >> MINUTE_SHIFT) & MIN_MASK;
+ tm->tm_hour = (time >> HOUR_SHIFT) & HOUR_MASK;
+ tm->tm_mday = (date >> MDAY_SHIFT) & DAY_MASK;
+ tm->tm_mon = (date >> MONTH_SHIFT) & MONTH_MASK;
+ tm->tm_year = (date >> YEAR_SHIFT) & YEAR_MASK;
+
+ bcd2tm(tm);
+ return 0;
+}
+
+/*
+ * spear_rtc_set_time - set the time
+ * @dev: rtc device in use
+ * @tm: holds date and time
+ *
+ * This function set time and date. On success it will return 0
+ * otherwise -ve error is returned.
+ */
+static int spear_rtc_set_time(struct device *dev, struct rtc_time *tm)
+{
+ struct platform_device *pdev = to_platform_device(dev);
+ struct rtc_device *rtc = platform_get_drvdata(pdev);
+ struct spear_rtc_config *config = dev_get_drvdata(&rtc->dev);
+ unsigned int time, date, err = 0;
+
+ if (tm2bcd(tm) < 0)
+ return -EINVAL;
+
+ rtc_wait_not_busy(config);
+ time = (tm->tm_sec << SECOND_SHIFT) | (tm->tm_min << MINUTE_SHIFT) |
+ (tm->tm_hour << HOUR_SHIFT);
+ date = (tm->tm_mday << MDAY_SHIFT) | (tm->tm_mon << MONTH_SHIFT) |
+ (tm->tm_year << YEAR_SHIFT);
+ writel(time, config->ioaddr + TIME_REG);
+ writel(date, config->ioaddr + DATE_REG);
+ err = is_write_complete(config);
+ if (err < 0)
+ return err;
+
+ return 0;
+}
+
+/*
+ * spear_rtc_read_alarm - read the alarm time
+ * @dev: rtc device in use
+ * @alm: holds alarm date and time
+ *
+ * This function read alarm time and date. On success it will return 0
+ * otherwise -ve error is returned.
+ */
+static int spear_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alm)
+{
+ struct platform_device *pdev = to_platform_device(dev);
+ struct rtc_device *rtc = platform_get_drvdata(pdev);
+ struct spear_rtc_config *config = dev_get_drvdata(&rtc->dev);
+ unsigned int time, date;
+
+ rtc_wait_not_busy(config);
+
+ time = readl(config->ioaddr + ALARM_TIME_REG);
+ date = readl(config->ioaddr + ALARM_DATE_REG);
+ alm->time.tm_sec = (time >> SECOND_SHIFT) & SECOND_MASK;
+ alm->time.tm_min = (time >> MINUTE_SHIFT) & MIN_MASK;
+ alm->time.tm_hour = (time >> HOUR_SHIFT) & HOUR_MASK;
+ alm->time.tm_mday = (date >> MDAY_SHIFT) & DAY_MASK;
+ alm->time.tm_mon = (date >> MONTH_SHIFT) & MONTH_MASK;
+ alm->time.tm_year = (date >> YEAR_SHIFT) & YEAR_MASK;
+
+ bcd2tm(&alm->time);
+ alm->enabled = readl(config->ioaddr + CTRL_REG) & INT_ENABLE;
+
+ return 0;
+}
+
+/*
+ * spear_rtc_set_alarm - set the alarm time
+ * @dev: rtc device in use
+ * @alm: holds alarm date and time
+ *
+ * This function set alarm time and date. On success it will return 0
+ * otherwise -ve error is returned.
+ */
+static int spear_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alm)
+{
+ struct platform_device *pdev = to_platform_device(dev);
+ struct rtc_device *rtc = platform_get_drvdata(pdev);
+ struct spear_rtc_config *config = dev_get_drvdata(&rtc->dev);
+ unsigned int time, date, err = 0;
+
+ if (tm2bcd(&alm->time) < 0)
+ return -EINVAL;
+
+ rtc_wait_not_busy(config);
+
+ time = (alm->time.tm_sec << SECOND_SHIFT) | (alm->time.tm_min <<
+ MINUTE_SHIFT) | (alm->time.tm_hour << HOUR_SHIFT);
+ date = (alm->time.tm_mday << MDAY_SHIFT) | (alm->time.tm_mon <<
+ MONTH_SHIFT) | (alm->time.tm_year << YEAR_SHIFT);
+
+ writel(time, config->ioaddr + ALARM_TIME_REG);
+ writel(date, config->ioaddr + ALARM_DATE_REG);
+ err = is_write_complete(config);
+ if (err < 0)
+ return err;
+
+ if (alm->enabled)
+ spear_rtc_enable_interrupt(config);
+ else
+ spear_rtc_disable_interrupt(config);
+
+ return 0;
+}
+static struct rtc_class_ops spear_rtc_ops = {
+ .read_time = spear_rtc_read_time,
+ .set_time = spear_rtc_set_time,
+ .read_alarm = spear_rtc_read_alarm,
+ .set_alarm = spear_rtc_set_alarm,
+};
+
+static int __devinit spear_rtc_probe(struct platform_device *pdev)
+{
+ struct resource *res;
+ struct rtc_device *rtc;
+ struct spear_rtc_config *config;
+ unsigned int status = 0;
+ int irq;
+
+ res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+ if (!res) {
+ dev_err(&pdev->dev, "no resource defined\n");
+ return -EBUSY;
+ }
+ if (!request_mem_region(res->start, resource_size(res), pdev->name)) {
+ dev_err(&pdev->dev, "rtc region already claimed\n");
+ return -EBUSY;
+ }
+
+ config = kzalloc(sizeof(*config), GFP_KERNEL);
+ if (!config) {
+ dev_err(&pdev->dev, "out of memory\n");
+ status = -ENOMEM;
+ goto err_release_region;
+ }
+
+ config->clk = clk_get(&pdev->dev, NULL);
+ if (IS_ERR(config->clk)) {
+ status = PTR_ERR(config->clk);
+ goto err_kfree;
+ }
+
+ status = clk_enable(config->clk);
+ if (status < 0)
+ goto err_clk_put;
+
+ config->ioaddr = ioremap(res->start, resource_size(res));
+ if (!config->ioaddr) {
+ dev_err(&pdev->dev, "ioremap fail\n");
+ status = -ENOMEM;
+ goto err_disable_clock;
+ }
+
+ spin_lock_init(&config->lock);
+
+ rtc = rtc_device_register(pdev->name, &pdev->dev, &spear_rtc_ops,
+ THIS_MODULE);
+ if (IS_ERR(rtc)) {
+ dev_err(&pdev->dev, "can't register RTC device, err %ld\n",
+ PTR_ERR(rtc));
+ status = PTR_ERR(rtc);
+ goto err_iounmap;
+ }
+
+ platform_set_drvdata(pdev, rtc);
+ dev_set_drvdata(&rtc->dev, config);
+
+ /* alarm irqs */
+ irq = platform_get_irq(pdev, 0);
+ if (irq < 0) {
+ dev_err(&pdev->dev, "no update irq?\n");
+ status = irq;
+ goto err_clear_platdata;
+ }
+
+ status = request_irq(irq, spear_rtc_irq, 0, pdev->name, rtc);
+ if (status) {
+ dev_err(&pdev->dev, "Alarm interrupt IRQ%d already \
+ claimed\n", irq);
+ goto err_clear_platdata;
+ }
+
+ if (!device_can_wakeup(&pdev->dev))
+ device_init_wakeup(&pdev->dev, 1);
+
+ return 0;
+
+err_clear_platdata:
+ platform_set_drvdata(pdev, NULL);
+ dev_set_drvdata(&rtc->dev, NULL);
+ rtc_device_unregister(rtc);
+err_iounmap:
+ iounmap(config->ioaddr);
+err_disable_clock:
+ clk_disable(config->clk);
+err_clk_put:
+ clk_put(config->clk);
+err_kfree:
+ kfree(config);
+err_release_region:
+ release_mem_region(res->start, resource_size(res));
+
+ return status;
+}
+
+static int __devexit spear_rtc_remove(struct platform_device *pdev)
+{
+ struct rtc_device *rtc = platform_get_drvdata(pdev);
+ struct spear_rtc_config *config = dev_get_drvdata(&rtc->dev);
+ int irq;
+ struct resource *res;
+
+ /* leave rtc running, but disable irqs */
+ spear_rtc_disable_interrupt(config);
+ device_init_wakeup(&pdev->dev, 0);
+ irq = platform_get_irq(pdev, 0);
+ if (irq)
+ free_irq(irq, pdev);
+ clk_disable(config->clk);
+ clk_put(config->clk);
+ iounmap(config->ioaddr);
+ kfree(config);
+ res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+ if (res)
+ release_mem_region(res->start, resource_size(res));
+ platform_set_drvdata(pdev, NULL);
+ dev_set_drvdata(&rtc->dev, NULL);
+ rtc_device_unregister(rtc);
+
+ return 0;
+}
+
+#ifdef CONFIG_PM
+
+static int spear_rtc_suspend(struct platform_device *pdev, pm_message_t state)
+{
+ struct rtc_device *rtc = platform_get_drvdata(pdev);
+ struct spear_rtc_config *config = dev_get_drvdata(&rtc->dev);
+ int irq;
+
+ irq = platform_get_irq(pdev, 0);
+ if (device_may_wakeup(&pdev->dev))
+ enable_irq_wake(irq);
+ else {
+ spear_rtc_disable_interrupt(config);
+ clk_disable(config->clk);
+ }
+
+ return 0;
+}
+
+static int spear_rtc_resume(struct platform_device *pdev)
+{
+ struct rtc_device *rtc = platform_get_drvdata(pdev);
+ struct spear_rtc_config *config = dev_get_drvdata(&rtc->dev);
+ int irq;
+
+ irq = platform_get_irq(pdev, 0);
+
+ if (device_may_wakeup(&pdev->dev))
+ disable_irq_wake(irq);
+ else {
+ clk_enable(config->clk);
+ spear_rtc_enable_interrupt(config);
+ }
+
+ return 0;
+}
+
+#else
+#define spear_rtc_suspend NULL
+#define spear_rtc_resume NULL
+#endif
+
+static void spear_rtc_shutdown(struct platform_device *pdev)
+{
+ struct rtc_device *rtc = platform_get_drvdata(pdev);
+ struct spear_rtc_config *config = dev_get_drvdata(&rtc->dev);
+
+ spear_rtc_disable_interrupt(config);
+ clk_disable(config->clk);
+}
+
+static struct platform_driver spear_rtc_driver = {
+ .probe = spear_rtc_probe,
+ .remove = __devexit_p(spear_rtc_remove),
+ .suspend = spear_rtc_suspend,
+ .resume = spear_rtc_resume,
+ .shutdown = spear_rtc_shutdown,
+ .driver = {
+ .name = "rtc-spear",
+ },
+};
+
+static int __init rtc_init(void)
+{
+ return platform_driver_register(&spear_rtc_driver);
+}
+module_init(rtc_init);
+
+static void __exit rtc_exit(void)
+{
+ platform_driver_unregister(&spear_rtc_driver);
+}
+module_exit(rtc_exit);
+
+MODULE_ALIAS("platform:rtc-spear");
+MODULE_AUTHOR("Rajeev Kumar <rajeev-dlh.kumar@st.com>");
+MODULE_DESCRIPTION("ST SPEAr Realtime Clock Driver (RTC)");
+MODULE_LICENSE("GPL");
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