/* * 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/of.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 rtc_device *rtc; struct clk *clk; spinlock_t lock; void __iomem *ioaddr; unsigned int irq_wake; }; 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 spear_rtc_config *config = dev_id; 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(config->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 spear_rtc_config *config = dev_get_drvdata(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 spear_rtc_config *config = dev_get_drvdata(dev); unsigned int time, date; 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); return is_write_complete(config); } /* * 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 spear_rtc_config *config = dev_get_drvdata(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 spear_rtc_config *config = dev_get_drvdata(dev); unsigned int time, date; int err; 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 int spear_alarm_irq_enable(struct device *dev, unsigned int enabled) { struct spear_rtc_config *config = dev_get_drvdata(dev); int ret = 0; spear_rtc_clear_interrupt(config); switch (enabled) { case 0: /* alarm off */ spear_rtc_disable_interrupt(config); break; case 1: /* alarm on */ spear_rtc_enable_interrupt(config); break; default: ret = -EINVAL; break; } return ret; } 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, .alarm_irq_enable = spear_alarm_irq_enable, }; static int spear_rtc_probe(struct platform_device *pdev) { struct resource *res; struct spear_rtc_config *config; 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; } config = devm_kzalloc(&pdev->dev, sizeof(*config), GFP_KERNEL); if (!config) return -ENOMEM; /* alarm irqs */ irq = platform_get_irq(pdev, 0); if (irq < 0) { dev_err(&pdev->dev, "no update irq?\n"); return irq; } status = devm_request_irq(&pdev->dev, irq, spear_rtc_irq, 0, pdev->name, config); if (status) { dev_err(&pdev->dev, "Alarm interrupt IRQ%d already claimed\n", irq); return status; } config->ioaddr = devm_ioremap_resource(&pdev->dev, res); if (IS_ERR(config->ioaddr)) return PTR_ERR(config->ioaddr); config->clk = devm_clk_get(&pdev->dev, NULL); if (IS_ERR(config->clk)) return PTR_ERR(config->clk); status = clk_prepare_enable(config->clk); if (status < 0) return status; spin_lock_init(&config->lock); platform_set_drvdata(pdev, config); config->rtc = devm_rtc_device_register(&pdev->dev, pdev->name, &spear_rtc_ops, THIS_MODULE); if (IS_ERR(config->rtc)) { dev_err(&pdev->dev, "can't register RTC device, err %ld\n", PTR_ERR(config->rtc)); status = PTR_ERR(config->rtc); goto err_disable_clock; } config->rtc->uie_unsupported = 1; if (!device_can_wakeup(&pdev->dev)) device_init_wakeup(&pdev->dev, 1); return 0; err_disable_clock: clk_disable_unprepare(config->clk); return status; } static int spear_rtc_remove(struct platform_device *pdev) { struct spear_rtc_config *config = platform_get_drvdata(pdev); spear_rtc_disable_interrupt(config); clk_disable_unprepare(config->clk); device_init_wakeup(&pdev->dev, 0); return 0; } #ifdef CONFIG_PM_SLEEP static int spear_rtc_suspend(struct device *dev) { struct platform_device *pdev = to_platform_device(dev); struct spear_rtc_config *config = platform_get_drvdata(pdev); int irq; irq = platform_get_irq(pdev, 0); if (device_may_wakeup(&pdev->dev)) { if (!enable_irq_wake(irq)) config->irq_wake = 1; } else { spear_rtc_disable_interrupt(config); clk_disable(config->clk); } return 0; } static int spear_rtc_resume(struct device *dev) { struct platform_device *pdev = to_platform_device(dev); struct spear_rtc_config *config = platform_get_drvdata(pdev); int irq; irq = platform_get_irq(pdev, 0); if (device_may_wakeup(&pdev->dev)) { if (config->irq_wake) { disable_irq_wake(irq); config->irq_wake = 0; } } else { clk_enable(config->clk); spear_rtc_enable_interrupt(config); } return 0; } #endif static SIMPLE_DEV_PM_OPS(spear_rtc_pm_ops, spear_rtc_suspend, spear_rtc_resume); static void spear_rtc_shutdown(struct platform_device *pdev) { struct spear_rtc_config *config = platform_get_drvdata(pdev); spear_rtc_disable_interrupt(config); clk_disable(config->clk); } #ifdef CONFIG_OF static const struct of_device_id spear_rtc_id_table[] = { { .compatible = "st,spear600-rtc" }, {} }; MODULE_DEVICE_TABLE(of, spear_rtc_id_table); #endif static struct platform_driver spear_rtc_driver = { .probe = spear_rtc_probe, .remove = spear_rtc_remove, .shutdown = spear_rtc_shutdown, .driver = { .name = "rtc-spear", .pm = &spear_rtc_pm_ops, .of_match_table = of_match_ptr(spear_rtc_id_table), }, }; module_platform_driver(spear_rtc_driver); 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");