/* * An RTC driver for the AVR32 AT32AP700x processor series. * * Copyright (C) 2007 Atmel Corporation * * This program is free software; you can redistribute it and/or modify it * under the terms of the GNU General Public License version 2 as published * by the Free Software Foundation. */ #include #include #include #include #include #include /* * This is a bare-bones RTC. It runs during most system sleep states, but has * no battery backup and gets reset during system restart. It must be * initialized from an external clock (network, I2C, etc) before it can be of * much use. * * The alarm functionality is limited by the hardware, not supporting * periodic interrupts. */ #define RTC_CTRL 0x00 #define RTC_CTRL_EN 0 #define RTC_CTRL_PCLR 1 #define RTC_CTRL_TOPEN 2 #define RTC_CTRL_PSEL 8 #define RTC_VAL 0x04 #define RTC_TOP 0x08 #define RTC_IER 0x10 #define RTC_IER_TOPI 0 #define RTC_IDR 0x14 #define RTC_IDR_TOPI 0 #define RTC_IMR 0x18 #define RTC_IMR_TOPI 0 #define RTC_ISR 0x1c #define RTC_ISR_TOPI 0 #define RTC_ICR 0x20 #define RTC_ICR_TOPI 0 #define RTC_BIT(name) (1 << RTC_##name) #define RTC_BF(name, value) ((value) << RTC_##name) #define rtc_readl(dev, reg) \ __raw_readl((dev)->regs + RTC_##reg) #define rtc_writel(dev, reg, value) \ __raw_writel((value), (dev)->regs + RTC_##reg) struct rtc_at32ap700x { struct rtc_device *rtc; void __iomem *regs; unsigned long alarm_time; unsigned long irq; /* Protect against concurrent register access. */ spinlock_t lock; }; static int at32_rtc_readtime(struct device *dev, struct rtc_time *tm) { struct rtc_at32ap700x *rtc = dev_get_drvdata(dev); unsigned long now; now = rtc_readl(rtc, VAL); rtc_time_to_tm(now, tm); return 0; } static int at32_rtc_settime(struct device *dev, struct rtc_time *tm) { struct rtc_at32ap700x *rtc = dev_get_drvdata(dev); unsigned long now; int ret; ret = rtc_tm_to_time(tm, &now); if (ret == 0) rtc_writel(rtc, VAL, now); return ret; } static int at32_rtc_readalarm(struct device *dev, struct rtc_wkalrm *alrm) { struct rtc_at32ap700x *rtc = dev_get_drvdata(dev); spin_lock_irq(&rtc->lock); rtc_time_to_tm(rtc->alarm_time, &alrm->time); alrm->enabled = rtc_readl(rtc, IMR) & RTC_BIT(IMR_TOPI) ? 1 : 0; alrm->pending = rtc_readl(rtc, ISR) & RTC_BIT(ISR_TOPI) ? 1 : 0; spin_unlock_irq(&rtc->lock); return 0; } static int at32_rtc_setalarm(struct device *dev, struct rtc_wkalrm *alrm) { struct rtc_at32ap700x *rtc = dev_get_drvdata(dev); unsigned long rtc_unix_time; unsigned long alarm_unix_time; int ret; rtc_unix_time = rtc_readl(rtc, VAL); ret = rtc_tm_to_time(&alrm->time, &alarm_unix_time); if (ret) return ret; if (alarm_unix_time < rtc_unix_time) return -EINVAL; spin_lock_irq(&rtc->lock); rtc->alarm_time = alarm_unix_time; rtc_writel(rtc, TOP, rtc->alarm_time); if (alrm->enabled) rtc_writel(rtc, CTRL, rtc_readl(rtc, CTRL) | RTC_BIT(CTRL_TOPEN)); else rtc_writel(rtc, CTRL, rtc_readl(rtc, CTRL) & ~RTC_BIT(CTRL_TOPEN)); spin_unlock_irq(&rtc->lock); return ret; } static int at32_rtc_alarm_irq_enable(struct device *dev, unsigned int enabled) { struct rtc_at32ap700x *rtc = dev_get_drvdata(dev); int ret = 0; spin_lock_irq(&rtc->lock); if(enabled) { if (rtc_readl(rtc, VAL) > rtc->alarm_time) { ret = -EINVAL; goto out; } rtc_writel(rtc, CTRL, rtc_readl(rtc, CTRL) | RTC_BIT(CTRL_TOPEN)); rtc_writel(rtc, ICR, RTC_BIT(ICR_TOPI)); rtc_writel(rtc, IER, RTC_BIT(IER_TOPI)); } else { rtc_writel(rtc, CTRL, rtc_readl(rtc, CTRL) & ~RTC_BIT(CTRL_TOPEN)); rtc_writel(rtc, IDR, RTC_BIT(IDR_TOPI)); rtc_writel(rtc, ICR, RTC_BIT(ICR_TOPI)); } out: spin_unlock_irq(&rtc->lock); return ret; } static irqreturn_t at32_rtc_interrupt(int irq, void *dev_id) { struct rtc_at32ap700x *rtc = (struct rtc_at32ap700x *)dev_id; unsigned long isr = rtc_readl(rtc, ISR); unsigned long events = 0; int ret = IRQ_NONE; spin_lock(&rtc->lock); if (isr & RTC_BIT(ISR_TOPI)) { rtc_writel(rtc, ICR, RTC_BIT(ICR_TOPI)); rtc_writel(rtc, IDR, RTC_BIT(IDR_TOPI)); rtc_writel(rtc, CTRL, rtc_readl(rtc, CTRL) & ~RTC_BIT(CTRL_TOPEN)); rtc_writel(rtc, VAL, rtc->alarm_time); events = RTC_AF | RTC_IRQF; rtc_update_irq(rtc->rtc, 1, events); ret = IRQ_HANDLED; } spin_unlock(&rtc->lock); return ret; } static struct rtc_class_ops at32_rtc_ops = { .read_time = at32_rtc_readtime, .set_time = at32_rtc_settime, .read_alarm = at32_rtc_readalarm, .set_alarm = at32_rtc_setalarm, .alarm_irq_enable = at32_rtc_alarm_irq_enable, }; static int __init at32_rtc_probe(struct platform_device *pdev) { struct resource *regs; struct rtc_at32ap700x *rtc; int irq; int ret; rtc = devm_kzalloc(&pdev->dev, sizeof(struct rtc_at32ap700x), GFP_KERNEL); if (!rtc) { dev_dbg(&pdev->dev, "out of memory\n"); return -ENOMEM; } regs = platform_get_resource(pdev, IORESOURCE_MEM, 0); if (!regs) { dev_dbg(&pdev->dev, "no mmio resource defined\n"); ret = -ENXIO; goto out; } irq = platform_get_irq(pdev, 0); if (irq <= 0) { dev_dbg(&pdev->dev, "could not get irq\n"); ret = -ENXIO; goto out; } rtc->irq = irq; rtc->regs = devm_ioremap(&pdev->dev, regs->start, resource_size(regs)); if (!rtc->regs) { ret = -ENOMEM; dev_dbg(&pdev->dev, "could not map I/O memory\n"); goto out; } spin_lock_init(&rtc->lock); /* * Maybe init RTC: count from zero at 1 Hz, disable wrap irq. * * Do not reset VAL register, as it can hold an old time * from last JTAG reset. */ if (!(rtc_readl(rtc, CTRL) & RTC_BIT(CTRL_EN))) { rtc_writel(rtc, CTRL, RTC_BIT(CTRL_PCLR)); rtc_writel(rtc, IDR, RTC_BIT(IDR_TOPI)); rtc_writel(rtc, CTRL, RTC_BF(CTRL_PSEL, 0xe) | RTC_BIT(CTRL_EN)); } ret = devm_request_irq(&pdev->dev, irq, at32_rtc_interrupt, IRQF_SHARED, "rtc", rtc); if (ret) { dev_dbg(&pdev->dev, "could not request irq %d\n", irq); goto out; } platform_set_drvdata(pdev, rtc); rtc->rtc = devm_rtc_device_register(&pdev->dev, pdev->name, &at32_rtc_ops, THIS_MODULE); if (IS_ERR(rtc->rtc)) { dev_dbg(&pdev->dev, "could not register rtc device\n"); ret = PTR_ERR(rtc->rtc); goto out; } device_init_wakeup(&pdev->dev, 1); dev_info(&pdev->dev, "Atmel RTC for AT32AP700x at %08lx irq %ld\n", (unsigned long)rtc->regs, rtc->irq); return 0; out: platform_set_drvdata(pdev, NULL); return ret; } static int __exit at32_rtc_remove(struct platform_device *pdev) { device_init_wakeup(&pdev->dev, 0); platform_set_drvdata(pdev, NULL); return 0; } MODULE_ALIAS("platform:at32ap700x_rtc"); static struct platform_driver at32_rtc_driver = { .remove = __exit_p(at32_rtc_remove), .driver = { .name = "at32ap700x_rtc", .owner = THIS_MODULE, }, }; module_platform_driver_probe(at32_rtc_driver, at32_rtc_probe); MODULE_AUTHOR("Hans-Christian Egtvedt "); MODULE_DESCRIPTION("Real time clock for AVR32 AT32AP700x"); MODULE_LICENSE("GPL");