X-Git-Url: https://gerrit.opnfv.org/gerrit/gitweb?a=blobdiff_plain;f=kernel%2Fdrivers%2Frtc%2Frtc-at32ap700x.c;fp=kernel%2Fdrivers%2Frtc%2Frtc-at32ap700x.c;h=d618d6c7ef93e232767206a35df19e7fafef11fe;hb=9ca8dbcc65cfc63d6f5ef3312a33184e1d726e00;hp=0000000000000000000000000000000000000000;hpb=98260f3884f4a202f9ca5eabed40b1354c489b29;p=kvmfornfv.git diff --git a/kernel/drivers/rtc/rtc-at32ap700x.c b/kernel/drivers/rtc/rtc-at32ap700x.c new file mode 100644 index 000000000..d618d6c7e --- /dev/null +++ b/kernel/drivers/rtc/rtc-at32ap700x.c @@ -0,0 +1,287 @@ +/* + * 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) + return -ENOMEM; + + regs = platform_get_resource(pdev, IORESOURCE_MEM, 0); + if (!regs) { + dev_dbg(&pdev->dev, "no mmio resource defined\n"); + return -ENXIO; + } + + irq = platform_get_irq(pdev, 0); + if (irq <= 0) { + dev_dbg(&pdev->dev, "could not get irq\n"); + return -ENXIO; + } + + rtc->irq = irq; + rtc->regs = devm_ioremap(&pdev->dev, regs->start, resource_size(regs)); + if (!rtc->regs) { + dev_dbg(&pdev->dev, "could not map I/O memory\n"); + return -ENOMEM; + } + 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); + return ret; + } + + 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"); + return PTR_ERR(rtc->rtc); + } + + 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; +} + +static int __exit at32_rtc_remove(struct platform_device *pdev) +{ + device_init_wakeup(&pdev->dev, 0); + + return 0; +} + +MODULE_ALIAS("platform:at32ap700x_rtc"); + +static struct platform_driver at32_rtc_driver = { + .remove = __exit_p(at32_rtc_remove), + .driver = { + .name = "at32ap700x_rtc", + }, +}; + +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");