/* * Freescale STMP37XX/STMP378X Real Time Clock driver * * Copyright (c) 2007 Sigmatel, Inc. * Peter Hartley, * * Copyright 2008 Freescale Semiconductor, Inc. All Rights Reserved. * Copyright 2008 Embedded Alley Solutions, Inc All Rights Reserved. * Copyright 2011 Wolfram Sang, Pengutronix e.K. */ /* * The code contained herein is licensed under the GNU General Public * License. You may obtain a copy of the GNU General Public License * Version 2 or later at the following locations: * * http://www.opensource.org/licenses/gpl-license.html * http://www.gnu.org/copyleft/gpl.html */ #include #include #include #include #include #include #include #include #include #include #include #include #define STMP3XXX_RTC_CTRL 0x0 #define STMP3XXX_RTC_CTRL_SET 0x4 #define STMP3XXX_RTC_CTRL_CLR 0x8 #define STMP3XXX_RTC_CTRL_ALARM_IRQ_EN 0x00000001 #define STMP3XXX_RTC_CTRL_ONEMSEC_IRQ_EN 0x00000002 #define STMP3XXX_RTC_CTRL_ALARM_IRQ 0x00000004 #define STMP3XXX_RTC_CTRL_WATCHDOGEN 0x00000010 #define STMP3XXX_RTC_STAT 0x10 #define STMP3XXX_RTC_STAT_STALE_SHIFT 16 #define STMP3XXX_RTC_STAT_RTC_PRESENT 0x80000000 #define STMP3XXX_RTC_SECONDS 0x30 #define STMP3XXX_RTC_ALARM 0x40 #define STMP3XXX_RTC_WATCHDOG 0x50 #define STMP3XXX_RTC_PERSISTENT0 0x60 #define STMP3XXX_RTC_PERSISTENT0_SET 0x64 #define STMP3XXX_RTC_PERSISTENT0_CLR 0x68 #define STMP3XXX_RTC_PERSISTENT0_ALARM_WAKE_EN 0x00000002 #define STMP3XXX_RTC_PERSISTENT0_ALARM_EN 0x00000004 #define STMP3XXX_RTC_PERSISTENT0_ALARM_WAKE 0x00000080 #define STMP3XXX_RTC_PERSISTENT1 0x70 /* missing bitmask in headers */ #define STMP3XXX_RTC_PERSISTENT1_FORCE_UPDATER 0x80000000 struct stmp3xxx_rtc_data { struct rtc_device *rtc; void __iomem *io; int irq_alarm; }; #if IS_ENABLED(CONFIG_STMP3XXX_RTC_WATCHDOG) /** * stmp3xxx_wdt_set_timeout - configure the watchdog inside the STMP3xxx RTC * @dev: the parent device of the watchdog (= the RTC) * @timeout: the desired value for the timeout register of the watchdog. * 0 disables the watchdog * * The watchdog needs one register and two bits which are in the RTC domain. * To handle the resource conflict, the RTC driver will create another * platform_device for the watchdog driver as a child of the RTC device. * The watchdog driver is passed the below accessor function via platform_data * to configure the watchdog. Locking is not needed because accessing SET/CLR * registers is atomic. */ static void stmp3xxx_wdt_set_timeout(struct device *dev, u32 timeout) { struct stmp3xxx_rtc_data *rtc_data = dev_get_drvdata(dev); if (timeout) { writel(timeout, rtc_data->io + STMP3XXX_RTC_WATCHDOG); writel(STMP3XXX_RTC_CTRL_WATCHDOGEN, rtc_data->io + STMP3XXX_RTC_CTRL + STMP_OFFSET_REG_SET); writel(STMP3XXX_RTC_PERSISTENT1_FORCE_UPDATER, rtc_data->io + STMP3XXX_RTC_PERSISTENT1 + STMP_OFFSET_REG_SET); } else { writel(STMP3XXX_RTC_CTRL_WATCHDOGEN, rtc_data->io + STMP3XXX_RTC_CTRL + STMP_OFFSET_REG_CLR); writel(STMP3XXX_RTC_PERSISTENT1_FORCE_UPDATER, rtc_data->io + STMP3XXX_RTC_PERSISTENT1 + STMP_OFFSET_REG_CLR); } } static struct stmp3xxx_wdt_pdata wdt_pdata = { .wdt_set_timeout = stmp3xxx_wdt_set_timeout, }; static void stmp3xxx_wdt_register(struct platform_device *rtc_pdev) { struct platform_device *wdt_pdev = platform_device_alloc("stmp3xxx_rtc_wdt", rtc_pdev->id); if (wdt_pdev) { wdt_pdev->dev.parent = &rtc_pdev->dev; wdt_pdev->dev.platform_data = &wdt_pdata; platform_device_add(wdt_pdev); } } #else static void stmp3xxx_wdt_register(struct platform_device *rtc_pdev) { } #endif /* CONFIG_STMP3XXX_RTC_WATCHDOG */ static void stmp3xxx_wait_time(struct stmp3xxx_rtc_data *rtc_data) { /* * The datasheet doesn't say which way round the * NEW_REGS/STALE_REGS bitfields go. In fact it's 0x1=P0, * 0x2=P1, .., 0x20=P5, 0x40=ALARM, 0x80=SECONDS */ while (readl(rtc_data->io + STMP3XXX_RTC_STAT) & (0x80 << STMP3XXX_RTC_STAT_STALE_SHIFT)) cpu_relax(); } /* Time read/write */ static int stmp3xxx_rtc_gettime(struct device *dev, struct rtc_time *rtc_tm) { struct stmp3xxx_rtc_data *rtc_data = dev_get_drvdata(dev); stmp3xxx_wait_time(rtc_data); rtc_time_to_tm(readl(rtc_data->io + STMP3XXX_RTC_SECONDS), rtc_tm); return 0; } static int stmp3xxx_rtc_set_mmss(struct device *dev, unsigned long t) { struct stmp3xxx_rtc_data *rtc_data = dev_get_drvdata(dev); writel(t, rtc_data->io + STMP3XXX_RTC_SECONDS); stmp3xxx_wait_time(rtc_data); return 0; } /* interrupt(s) handler */ static irqreturn_t stmp3xxx_rtc_interrupt(int irq, void *dev_id) { struct stmp3xxx_rtc_data *rtc_data = dev_get_drvdata(dev_id); u32 status = readl(rtc_data->io + STMP3XXX_RTC_CTRL); if (status & STMP3XXX_RTC_CTRL_ALARM_IRQ) { writel(STMP3XXX_RTC_CTRL_ALARM_IRQ, rtc_data->io + STMP3XXX_RTC_CTRL_CLR); rtc_update_irq(rtc_data->rtc, 1, RTC_AF | RTC_IRQF); return IRQ_HANDLED; } return IRQ_NONE; } static int stmp3xxx_alarm_irq_enable(struct device *dev, unsigned int enabled) { struct stmp3xxx_rtc_data *rtc_data = dev_get_drvdata(dev); if (enabled) { writel(STMP3XXX_RTC_PERSISTENT0_ALARM_EN | STMP3XXX_RTC_PERSISTENT0_ALARM_WAKE_EN, rtc_data->io + STMP3XXX_RTC_PERSISTENT0_SET); writel(STMP3XXX_RTC_CTRL_ALARM_IRQ_EN, rtc_data->io + STMP3XXX_RTC_CTRL_SET); } else { writel(STMP3XXX_RTC_PERSISTENT0_ALARM_EN | STMP3XXX_RTC_PERSISTENT0_ALARM_WAKE_EN, rtc_data->io + STMP3XXX_RTC_PERSISTENT0_CLR); writel(STMP3XXX_RTC_CTRL_ALARM_IRQ_EN, rtc_data->io + STMP3XXX_RTC_CTRL_CLR); } return 0; } static int stmp3xxx_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alm) { struct stmp3xxx_rtc_data *rtc_data = dev_get_drvdata(dev); rtc_time_to_tm(readl(rtc_data->io + STMP3XXX_RTC_ALARM), &alm->time); return 0; } static int stmp3xxx_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alm) { unsigned long t; struct stmp3xxx_rtc_data *rtc_data = dev_get_drvdata(dev); rtc_tm_to_time(&alm->time, &t); writel(t, rtc_data->io + STMP3XXX_RTC_ALARM); stmp3xxx_alarm_irq_enable(dev, alm->enabled); return 0; } static struct rtc_class_ops stmp3xxx_rtc_ops = { .alarm_irq_enable = stmp3xxx_alarm_irq_enable, .read_time = stmp3xxx_rtc_gettime, .set_mmss = stmp3xxx_rtc_set_mmss, .read_alarm = stmp3xxx_rtc_read_alarm, .set_alarm = stmp3xxx_rtc_set_alarm, }; static int stmp3xxx_rtc_remove(struct platform_device *pdev) { struct stmp3xxx_rtc_data *rtc_data = platform_get_drvdata(pdev); if (!rtc_data) return 0; writel(STMP3XXX_RTC_CTRL_ALARM_IRQ_EN, rtc_data->io + STMP3XXX_RTC_CTRL_CLR); platform_set_drvdata(pdev, NULL); return 0; } static int stmp3xxx_rtc_probe(struct platform_device *pdev) { struct stmp3xxx_rtc_data *rtc_data; struct resource *r; int err; rtc_data = devm_kzalloc(&pdev->dev, sizeof(*rtc_data), GFP_KERNEL); if (!rtc_data) return -ENOMEM; r = platform_get_resource(pdev, IORESOURCE_MEM, 0); if (!r) { dev_err(&pdev->dev, "failed to get resource\n"); return -ENXIO; } rtc_data->io = devm_ioremap(&pdev->dev, r->start, resource_size(r)); if (!rtc_data->io) { dev_err(&pdev->dev, "ioremap failed\n"); return -EIO; } rtc_data->irq_alarm = platform_get_irq(pdev, 0); if (!(readl(STMP3XXX_RTC_STAT + rtc_data->io) & STMP3XXX_RTC_STAT_RTC_PRESENT)) { dev_err(&pdev->dev, "no device onboard\n"); return -ENODEV; } platform_set_drvdata(pdev, rtc_data); stmp_reset_block(rtc_data->io); writel(STMP3XXX_RTC_PERSISTENT0_ALARM_EN | STMP3XXX_RTC_PERSISTENT0_ALARM_WAKE_EN | STMP3XXX_RTC_PERSISTENT0_ALARM_WAKE, rtc_data->io + STMP3XXX_RTC_PERSISTENT0_CLR); writel(STMP3XXX_RTC_CTRL_ONEMSEC_IRQ_EN | STMP3XXX_RTC_CTRL_ALARM_IRQ_EN, rtc_data->io + STMP3XXX_RTC_CTRL_CLR); rtc_data->rtc = devm_rtc_device_register(&pdev->dev, pdev->name, &stmp3xxx_rtc_ops, THIS_MODULE); if (IS_ERR(rtc_data->rtc)) { err = PTR_ERR(rtc_data->rtc); goto out; } err = devm_request_irq(&pdev->dev, rtc_data->irq_alarm, stmp3xxx_rtc_interrupt, 0, "RTC alarm", &pdev->dev); if (err) { dev_err(&pdev->dev, "Cannot claim IRQ%d\n", rtc_data->irq_alarm); goto out; } stmp3xxx_wdt_register(pdev); return 0; out: platform_set_drvdata(pdev, NULL); return err; } #ifdef CONFIG_PM_SLEEP static int stmp3xxx_rtc_suspend(struct device *dev) { return 0; } static int stmp3xxx_rtc_resume(struct device *dev) { struct stmp3xxx_rtc_data *rtc_data = dev_get_drvdata(dev); stmp_reset_block(rtc_data->io); writel(STMP3XXX_RTC_PERSISTENT0_ALARM_EN | STMP3XXX_RTC_PERSISTENT0_ALARM_WAKE_EN | STMP3XXX_RTC_PERSISTENT0_ALARM_WAKE, rtc_data->io + STMP3XXX_RTC_PERSISTENT0_CLR); return 0; } #endif static SIMPLE_DEV_PM_OPS(stmp3xxx_rtc_pm_ops, stmp3xxx_rtc_suspend, stmp3xxx_rtc_resume); static const struct of_device_id rtc_dt_ids[] = { { .compatible = "fsl,stmp3xxx-rtc", }, { /* sentinel */ } }; MODULE_DEVICE_TABLE(of, rtc_dt_ids); static struct platform_driver stmp3xxx_rtcdrv = { .probe = stmp3xxx_rtc_probe, .remove = stmp3xxx_rtc_remove, .driver = { .name = "stmp3xxx-rtc", .owner = THIS_MODULE, .pm = &stmp3xxx_rtc_pm_ops, .of_match_table = of_match_ptr(rtc_dt_ids), }, }; module_platform_driver(stmp3xxx_rtcdrv); MODULE_DESCRIPTION("STMP3xxx RTC Driver"); MODULE_AUTHOR("dmitry pervushin and " "Wolfram Sang "); MODULE_LICENSE("GPL");