/* * TI OMAP1 Real Time Clock interface for Linux * * Copyright (C) 2003 MontaVista Software, Inc. * Author: George G. Davis <gdavis@mvista.com> or <source@mvista.com> * * Copyright (C) 2006 David Brownell (new RTC framework) * * 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; either version * 2 of the License, or (at your option) any later version. */ #include <linux/kernel.h> #include <linux/init.h> #include <linux/module.h> #include <linux/ioport.h> #include <linux/delay.h> #include <linux/rtc.h> #include <linux/bcd.h> #include <linux/platform_device.h> #include <linux/of.h> #include <linux/of_device.h> #include <linux/pm_runtime.h> #include <linux/io.h> /* The OMAP1 RTC is a year/month/day/hours/minutes/seconds BCD clock * with century-range alarm matching, driven by the 32kHz clock. * * The main user-visible ways it differs from PC RTCs are by omitting * "don't care" alarm fields and sub-second periodic IRQs, and having * an autoadjust mechanism to calibrate to the true oscillator rate. * * Board-specific wiring options include using split power mode with * RTC_OFF_NOFF used as the reset signal (so the RTC won't be reset), * and wiring RTC_WAKE_INT (so the RTC alarm can wake the system from * low power modes) for OMAP1 boards (OMAP-L138 has this built into * the SoC). See the BOARD-SPECIFIC CUSTOMIZATION comment. */ /* RTC registers */ #define OMAP_RTC_SECONDS_REG 0x00 #define OMAP_RTC_MINUTES_REG 0x04 #define OMAP_RTC_HOURS_REG 0x08 #define OMAP_RTC_DAYS_REG 0x0C #define OMAP_RTC_MONTHS_REG 0x10 #define OMAP_RTC_YEARS_REG 0x14 #define OMAP_RTC_WEEKS_REG 0x18 #define OMAP_RTC_ALARM_SECONDS_REG 0x20 #define OMAP_RTC_ALARM_MINUTES_REG 0x24 #define OMAP_RTC_ALARM_HOURS_REG 0x28 #define OMAP_RTC_ALARM_DAYS_REG 0x2c #define OMAP_RTC_ALARM_MONTHS_REG 0x30 #define OMAP_RTC_ALARM_YEARS_REG 0x34 #define OMAP_RTC_CTRL_REG 0x40 #define OMAP_RTC_STATUS_REG 0x44 #define OMAP_RTC_INTERRUPTS_REG 0x48 #define OMAP_RTC_COMP_LSB_REG 0x4c #define OMAP_RTC_COMP_MSB_REG 0x50 #define OMAP_RTC_OSC_REG 0x54 #define OMAP_RTC_KICK0_REG 0x6c #define OMAP_RTC_KICK1_REG 0x70 #define OMAP_RTC_IRQWAKEEN 0x7c /* OMAP_RTC_CTRL_REG bit fields: */ #define OMAP_RTC_CTRL_SPLIT BIT(7) #define OMAP_RTC_CTRL_DISABLE BIT(6) #define OMAP_RTC_CTRL_SET_32_COUNTER BIT(5) #define OMAP_RTC_CTRL_TEST BIT(4) #define OMAP_RTC_CTRL_MODE_12_24 BIT(3) #define OMAP_RTC_CTRL_AUTO_COMP BIT(2) #define OMAP_RTC_CTRL_ROUND_30S BIT(1) #define OMAP_RTC_CTRL_STOP BIT(0) /* OMAP_RTC_STATUS_REG bit fields: */ #define OMAP_RTC_STATUS_POWER_UP BIT(7) #define OMAP_RTC_STATUS_ALARM BIT(6) #define OMAP_RTC_STATUS_1D_EVENT BIT(5) #define OMAP_RTC_STATUS_1H_EVENT BIT(4) #define OMAP_RTC_STATUS_1M_EVENT BIT(3) #define OMAP_RTC_STATUS_1S_EVENT BIT(2) #define OMAP_RTC_STATUS_RUN BIT(1) #define OMAP_RTC_STATUS_BUSY BIT(0) /* OMAP_RTC_INTERRUPTS_REG bit fields: */ #define OMAP_RTC_INTERRUPTS_IT_ALARM BIT(3) #define OMAP_RTC_INTERRUPTS_IT_TIMER BIT(2) /* OMAP_RTC_OSC_REG bit fields: */ #define OMAP_RTC_OSC_32KCLK_EN BIT(6) /* OMAP_RTC_IRQWAKEEN bit fields: */ #define OMAP_RTC_IRQWAKEEN_ALARM_WAKEEN BIT(1) /* OMAP_RTC_KICKER values */ #define KICK0_VALUE 0x83e70b13 #define KICK1_VALUE 0x95a4f1e0 struct omap_rtc_device_type { bool has_32kclk_en; bool has_kicker; bool has_irqwakeen; bool has_power_up_reset; }; struct omap_rtc { struct rtc_device *rtc; void __iomem *base; int irq_alarm; int irq_timer; u8 interrupts_reg; const struct omap_rtc_device_type *type; }; static inline u8 rtc_read(struct omap_rtc *rtc, unsigned int reg) { return readb(rtc->base + reg); } static inline void rtc_write(struct omap_rtc *rtc, unsigned int reg, u8 val) { writeb(val, rtc->base + reg); } static inline void rtc_writel(struct omap_rtc *rtc, unsigned int reg, u32 val) { writel(val, rtc->base + reg); } /* we rely on the rtc framework to handle locking (rtc->ops_lock), * so the only other requirement is that register accesses which * require BUSY to be clear are made with IRQs locally disabled */ static void rtc_wait_not_busy(struct omap_rtc *rtc) { int count = 0; u8 status; /* BUSY may stay active for 1/32768 second (~30 usec) */ for (count = 0; count < 50; count++) { status = rtc_read(rtc, OMAP_RTC_STATUS_REG); if ((status & (u8)OMAP_RTC_STATUS_BUSY) == 0) break; udelay(1); } /* now we have ~15 usec to read/write various registers */ } static irqreturn_t rtc_irq(int irq, void *dev_id) { struct omap_rtc *rtc = dev_id; unsigned long events = 0; u8 irq_data; irq_data = rtc_read(rtc, OMAP_RTC_STATUS_REG); /* alarm irq? */ if (irq_data & OMAP_RTC_STATUS_ALARM) { rtc_write(rtc, OMAP_RTC_STATUS_REG, OMAP_RTC_STATUS_ALARM); events |= RTC_IRQF | RTC_AF; } /* 1/sec periodic/update irq? */ if (irq_data & OMAP_RTC_STATUS_1S_EVENT) events |= RTC_IRQF | RTC_UF; rtc_update_irq(rtc->rtc, 1, events); return IRQ_HANDLED; } static int omap_rtc_alarm_irq_enable(struct device *dev, unsigned int enabled) { struct omap_rtc *rtc = dev_get_drvdata(dev); u8 reg, irqwake_reg = 0; local_irq_disable(); rtc_wait_not_busy(rtc); reg = rtc_read(rtc, OMAP_RTC_INTERRUPTS_REG); if (rtc->type->has_irqwakeen) irqwake_reg = rtc_read(rtc, OMAP_RTC_IRQWAKEEN); if (enabled) { reg |= OMAP_RTC_INTERRUPTS_IT_ALARM; irqwake_reg |= OMAP_RTC_IRQWAKEEN_ALARM_WAKEEN; } else { reg &= ~OMAP_RTC_INTERRUPTS_IT_ALARM; irqwake_reg &= ~OMAP_RTC_IRQWAKEEN_ALARM_WAKEEN; } rtc_wait_not_busy(rtc); rtc_write(rtc, OMAP_RTC_INTERRUPTS_REG, reg); if (rtc->type->has_irqwakeen) rtc_write(rtc, OMAP_RTC_IRQWAKEEN, irqwake_reg); local_irq_enable(); return 0; } /* this hardware doesn't support "don't care" alarm fields */ 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); /* epoch == 1900 */ if (tm->tm_year < 100 || tm->tm_year > 199) return -EINVAL; tm->tm_year = bin2bcd(tm->tm_year - 100); 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) + 100; } static void omap_rtc_read_time_raw(struct omap_rtc *rtc, struct rtc_time *tm) { tm->tm_sec = rtc_read(rtc, OMAP_RTC_SECONDS_REG); tm->tm_min = rtc_read(rtc, OMAP_RTC_MINUTES_REG); tm->tm_hour = rtc_read(rtc, OMAP_RTC_HOURS_REG); tm->tm_mday = rtc_read(rtc, OMAP_RTC_DAYS_REG); tm->tm_mon = rtc_read(rtc, OMAP_RTC_MONTHS_REG); tm->tm_year = rtc_read(rtc, OMAP_RTC_YEARS_REG); } static int omap_rtc_read_time(struct device *dev, struct rtc_time *tm) { struct omap_rtc *rtc = dev_get_drvdata(dev); /* we don't report wday/yday/isdst ... */ local_irq_disable(); rtc_wait_not_busy(rtc); omap_rtc_read_time_raw(rtc, tm); local_irq_enable(); bcd2tm(tm); return 0; } static int omap_rtc_set_time(struct device *dev, struct rtc_time *tm) { struct omap_rtc *rtc = dev_get_drvdata(dev); if (tm2bcd(tm) < 0) return -EINVAL; local_irq_disable(); rtc_wait_not_busy(rtc); rtc_write(rtc, OMAP_RTC_YEARS_REG, tm->tm_year); rtc_write(rtc, OMAP_RTC_MONTHS_REG, tm->tm_mon); rtc_write(rtc, OMAP_RTC_DAYS_REG, tm->tm_mday); rtc_write(rtc, OMAP_RTC_HOURS_REG, tm->tm_hour); rtc_write(rtc, OMAP_RTC_MINUTES_REG, tm->tm_min); rtc_write(rtc, OMAP_RTC_SECONDS_REG, tm->tm_sec); local_irq_enable(); return 0; } static int omap_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alm) { struct omap_rtc *rtc = dev_get_drvdata(dev); local_irq_disable(); rtc_wait_not_busy(rtc); alm->time.tm_sec = rtc_read(rtc, OMAP_RTC_ALARM_SECONDS_REG); alm->time.tm_min = rtc_read(rtc, OMAP_RTC_ALARM_MINUTES_REG); alm->time.tm_hour = rtc_read(rtc, OMAP_RTC_ALARM_HOURS_REG); alm->time.tm_mday = rtc_read(rtc, OMAP_RTC_ALARM_DAYS_REG); alm->time.tm_mon = rtc_read(rtc, OMAP_RTC_ALARM_MONTHS_REG); alm->time.tm_year = rtc_read(rtc, OMAP_RTC_ALARM_YEARS_REG); local_irq_enable(); bcd2tm(&alm->time); alm->enabled = !!(rtc_read(rtc, OMAP_RTC_INTERRUPTS_REG) & OMAP_RTC_INTERRUPTS_IT_ALARM); return 0; } static int omap_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alm) { struct omap_rtc *rtc = dev_get_drvdata(dev); u8 reg, irqwake_reg = 0; if (tm2bcd(&alm->time) < 0) return -EINVAL; local_irq_disable(); rtc_wait_not_busy(rtc); rtc_write(rtc, OMAP_RTC_ALARM_YEARS_REG, alm->time.tm_year); rtc_write(rtc, OMAP_RTC_ALARM_MONTHS_REG, alm->time.tm_mon); rtc_write(rtc, OMAP_RTC_ALARM_DAYS_REG, alm->time.tm_mday); rtc_write(rtc, OMAP_RTC_ALARM_HOURS_REG, alm->time.tm_hour); rtc_write(rtc, OMAP_RTC_ALARM_MINUTES_REG, alm->time.tm_min); rtc_write(rtc, OMAP_RTC_ALARM_SECONDS_REG, alm->time.tm_sec); reg = rtc_read(rtc, OMAP_RTC_INTERRUPTS_REG); if (rtc->type->has_irqwakeen) irqwake_reg = rtc_read(rtc, OMAP_RTC_IRQWAKEEN); if (alm->enabled) { reg |= OMAP_RTC_INTERRUPTS_IT_ALARM; irqwake_reg |= OMAP_RTC_IRQWAKEEN_ALARM_WAKEEN; } else { reg &= ~OMAP_RTC_INTERRUPTS_IT_ALARM; irqwake_reg &= ~OMAP_RTC_IRQWAKEEN_ALARM_WAKEEN; } rtc_write(rtc, OMAP_RTC_INTERRUPTS_REG, reg); if (rtc->type->has_irqwakeen) rtc_write(rtc, OMAP_RTC_IRQWAKEEN, irqwake_reg); local_irq_enable(); return 0; } static struct rtc_class_ops omap_rtc_ops = { .read_time = omap_rtc_read_time, .set_time = omap_rtc_set_time, .read_alarm = omap_rtc_read_alarm, .set_alarm = omap_rtc_set_alarm, .alarm_irq_enable = omap_rtc_alarm_irq_enable, }; static const struct omap_rtc_device_type omap_rtc_default_type = { .has_power_up_reset = true, }; static const struct omap_rtc_device_type omap_rtc_am3352_type = { .has_32kclk_en = true, .has_kicker = true, .has_irqwakeen = true, }; static const struct omap_rtc_device_type omap_rtc_da830_type = { .has_kicker = true, }; static const struct platform_device_id omap_rtc_id_table[] = { { .name = "omap_rtc", .driver_data = (kernel_ulong_t)&omap_rtc_default_type, }, { .name = "am3352-rtc", .driver_data = (kernel_ulong_t)&omap_rtc_am3352_type, }, { .name = "da830-rtc", .driver_data = (kernel_ulong_t)&omap_rtc_da830_type, }, { /* sentinel */ } }; MODULE_DEVICE_TABLE(platform, omap_rtc_id_table); static const struct of_device_id omap_rtc_of_match[] = { { .compatible = "ti,am3352-rtc", .data = &omap_rtc_am3352_type, }, { .compatible = "ti,da830-rtc", .data = &omap_rtc_da830_type, }, { /* sentinel */ } }; MODULE_DEVICE_TABLE(of, omap_rtc_of_match); static int __init omap_rtc_probe(struct platform_device *pdev) { struct omap_rtc *rtc; struct resource *res; u8 reg, mask, new_ctrl; const struct platform_device_id *id_entry; const struct of_device_id *of_id; int ret; rtc = devm_kzalloc(&pdev->dev, sizeof(*rtc), GFP_KERNEL); if (!rtc) return -ENOMEM; of_id = of_match_device(omap_rtc_of_match, &pdev->dev); if (of_id) { rtc->type = of_id->data; } else { id_entry = platform_get_device_id(pdev); rtc->type = (void *)id_entry->driver_data; } rtc->irq_timer = platform_get_irq(pdev, 0); if (rtc->irq_timer <= 0) return -ENOENT; rtc->irq_alarm = platform_get_irq(pdev, 1); if (rtc->irq_alarm <= 0) return -ENOENT; res = platform_get_resource(pdev, IORESOURCE_MEM, 0); rtc->base = devm_ioremap_resource(&pdev->dev, res); if (IS_ERR(rtc->base)) return PTR_ERR(rtc->base); platform_set_drvdata(pdev, rtc); /* Enable the clock/module so that we can access the registers */ pm_runtime_enable(&pdev->dev); pm_runtime_get_sync(&pdev->dev); if (rtc->type->has_kicker) { rtc_writel(rtc, OMAP_RTC_KICK0_REG, KICK0_VALUE); rtc_writel(rtc, OMAP_RTC_KICK1_REG, KICK1_VALUE); } /* * disable interrupts * * NOTE: ALARM2 is not cleared on AM3352 if rtc_write (writeb) is used */ rtc_writel(rtc, OMAP_RTC_INTERRUPTS_REG, 0); /* enable RTC functional clock */ if (rtc->type->has_32kclk_en) { reg = rtc_read(rtc, OMAP_RTC_OSC_REG); rtc_writel(rtc, OMAP_RTC_OSC_REG, reg | OMAP_RTC_OSC_32KCLK_EN); } /* clear old status */ reg = rtc_read(rtc, OMAP_RTC_STATUS_REG); mask = OMAP_RTC_STATUS_ALARM; if (rtc->type->has_power_up_reset) { mask |= OMAP_RTC_STATUS_POWER_UP; if (reg & OMAP_RTC_STATUS_POWER_UP) dev_info(&pdev->dev, "RTC power up reset detected\n"); } if (reg & mask) rtc_write(rtc, OMAP_RTC_STATUS_REG, reg & mask); /* On boards with split power, RTC_ON_NOFF won't reset the RTC */ reg = rtc_read(rtc, OMAP_RTC_CTRL_REG); if (reg & (u8) OMAP_RTC_CTRL_STOP) dev_info(&pdev->dev, "already running\n"); /* force to 24 hour mode */ new_ctrl = reg & (OMAP_RTC_CTRL_SPLIT|OMAP_RTC_CTRL_AUTO_COMP); new_ctrl |= OMAP_RTC_CTRL_STOP; /* BOARD-SPECIFIC CUSTOMIZATION CAN GO HERE: * * - Device wake-up capability setting should come through chip * init logic. OMAP1 boards should initialize the "wakeup capable" * flag in the platform device if the board is wired right for * being woken up by RTC alarm. For OMAP-L138, this capability * is built into the SoC by the "Deep Sleep" capability. * * - Boards wired so RTC_ON_nOFF is used as the reset signal, * rather than nPWRON_RESET, should forcibly enable split * power mode. (Some chip errata report that RTC_CTRL_SPLIT * is write-only, and always reads as zero...) */ if (new_ctrl & (u8) OMAP_RTC_CTRL_SPLIT) dev_info(&pdev->dev, "split power mode\n"); if (reg != new_ctrl) rtc_write(rtc, OMAP_RTC_CTRL_REG, new_ctrl); device_init_wakeup(&pdev->dev, true); rtc->rtc = devm_rtc_device_register(&pdev->dev, pdev->name, &omap_rtc_ops, THIS_MODULE); if (IS_ERR(rtc->rtc)) { ret = PTR_ERR(rtc->rtc); goto err; } /* handle periodic and alarm irqs */ ret = devm_request_irq(&pdev->dev, rtc->irq_timer, rtc_irq, 0, dev_name(&rtc->rtc->dev), rtc); if (ret) goto err; if (rtc->irq_timer != rtc->irq_alarm) { ret = devm_request_irq(&pdev->dev, rtc->irq_alarm, rtc_irq, 0, dev_name(&rtc->rtc->dev), rtc); if (ret) goto err; } return 0; err: device_init_wakeup(&pdev->dev, false); if (rtc->type->has_kicker) rtc_writel(rtc, OMAP_RTC_KICK0_REG, 0); pm_runtime_put_sync(&pdev->dev); pm_runtime_disable(&pdev->dev); return ret; } static int __exit omap_rtc_remove(struct platform_device *pdev) { struct omap_rtc *rtc = platform_get_drvdata(pdev); device_init_wakeup(&pdev->dev, 0); /* leave rtc running, but disable irqs */ rtc_write(rtc, OMAP_RTC_INTERRUPTS_REG, 0); if (rtc->type->has_kicker) rtc_writel(rtc, OMAP_RTC_KICK0_REG, 0); /* Disable the clock/module */ pm_runtime_put_sync(&pdev->dev); pm_runtime_disable(&pdev->dev); return 0; } #ifdef CONFIG_PM_SLEEP static int omap_rtc_suspend(struct device *dev) { struct omap_rtc *rtc = dev_get_drvdata(dev); rtc->interrupts_reg = rtc_read(rtc, OMAP_RTC_INTERRUPTS_REG); /* FIXME the RTC alarm is not currently acting as a wakeup event * source on some platforms, and in fact this enable() call is just * saving a flag that's never used... */ if (device_may_wakeup(dev)) enable_irq_wake(rtc->irq_alarm); else rtc_write(rtc, OMAP_RTC_INTERRUPTS_REG, 0); /* Disable the clock/module */ pm_runtime_put_sync(dev); return 0; } static int omap_rtc_resume(struct device *dev) { struct omap_rtc *rtc = dev_get_drvdata(dev); /* Enable the clock/module so that we can access the registers */ pm_runtime_get_sync(dev); if (device_may_wakeup(dev)) disable_irq_wake(rtc->irq_alarm); else rtc_write(rtc, OMAP_RTC_INTERRUPTS_REG, rtc->interrupts_reg); return 0; } #endif static SIMPLE_DEV_PM_OPS(omap_rtc_pm_ops, omap_rtc_suspend, omap_rtc_resume); static void omap_rtc_shutdown(struct platform_device *pdev) { struct omap_rtc *rtc = platform_get_drvdata(pdev); rtc_write(rtc, OMAP_RTC_INTERRUPTS_REG, 0); } static struct platform_driver omap_rtc_driver = { .remove = __exit_p(omap_rtc_remove), .shutdown = omap_rtc_shutdown, .driver = { .name = "omap_rtc", .owner = THIS_MODULE, .pm = &omap_rtc_pm_ops, .of_match_table = omap_rtc_of_match, }, .id_table = omap_rtc_id_table, }; module_platform_driver_probe(omap_rtc_driver, omap_rtc_probe); MODULE_ALIAS("platform:omap_rtc"); MODULE_AUTHOR("George G. Davis (and others)"); MODULE_LICENSE("GPL");