| /* |
| * Copyright (C) 2010 NXP Semiconductors |
| * |
| * 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. |
| * |
| * You should have received a copy of the GNU General Public License along |
| * with this program; if not, write to the Free Software Foundation, Inc., |
| * 675 Mass Ave, Cambridge, MA 02139, USA. |
| */ |
| |
| #include <linux/kernel.h> |
| #include <linux/module.h> |
| #include <linux/init.h> |
| #include <linux/platform_device.h> |
| #include <linux/spinlock.h> |
| #include <linux/rtc.h> |
| #include <linux/slab.h> |
| #include <linux/io.h> |
| |
| /* |
| * Clock and Power control register offsets |
| */ |
| #define LPC32XX_RTC_UCOUNT 0x00 |
| #define LPC32XX_RTC_DCOUNT 0x04 |
| #define LPC32XX_RTC_MATCH0 0x08 |
| #define LPC32XX_RTC_MATCH1 0x0C |
| #define LPC32XX_RTC_CTRL 0x10 |
| #define LPC32XX_RTC_INTSTAT 0x14 |
| #define LPC32XX_RTC_KEY 0x18 |
| #define LPC32XX_RTC_SRAM 0x80 |
| |
| #define LPC32XX_RTC_CTRL_MATCH0 (1 << 0) |
| #define LPC32XX_RTC_CTRL_MATCH1 (1 << 1) |
| #define LPC32XX_RTC_CTRL_ONSW_MATCH0 (1 << 2) |
| #define LPC32XX_RTC_CTRL_ONSW_MATCH1 (1 << 3) |
| #define LPC32XX_RTC_CTRL_SW_RESET (1 << 4) |
| #define LPC32XX_RTC_CTRL_CNTR_DIS (1 << 6) |
| #define LPC32XX_RTC_CTRL_ONSW_FORCE_HI (1 << 7) |
| |
| #define LPC32XX_RTC_INTSTAT_MATCH0 (1 << 0) |
| #define LPC32XX_RTC_INTSTAT_MATCH1 (1 << 1) |
| #define LPC32XX_RTC_INTSTAT_ONSW (1 << 2) |
| |
| #define LPC32XX_RTC_KEY_ONSW_LOADVAL 0xB5C13F27 |
| |
| #define RTC_NAME "rtc-lpc32xx" |
| |
| #define rtc_readl(dev, reg) \ |
| __raw_readl((dev)->rtc_base + (reg)) |
| #define rtc_writel(dev, reg, val) \ |
| __raw_writel((val), (dev)->rtc_base + (reg)) |
| |
| struct lpc32xx_rtc { |
| void __iomem *rtc_base; |
| int irq; |
| unsigned char alarm_enabled; |
| struct rtc_device *rtc; |
| spinlock_t lock; |
| }; |
| |
| static int lpc32xx_rtc_read_time(struct device *dev, struct rtc_time *time) |
| { |
| unsigned long elapsed_sec; |
| struct lpc32xx_rtc *rtc = dev_get_drvdata(dev); |
| |
| elapsed_sec = rtc_readl(rtc, LPC32XX_RTC_UCOUNT); |
| rtc_time_to_tm(elapsed_sec, time); |
| |
| return rtc_valid_tm(time); |
| } |
| |
| static int lpc32xx_rtc_set_mmss(struct device *dev, unsigned long secs) |
| { |
| struct lpc32xx_rtc *rtc = dev_get_drvdata(dev); |
| u32 tmp; |
| |
| spin_lock_irq(&rtc->lock); |
| |
| /* RTC must be disabled during count update */ |
| tmp = rtc_readl(rtc, LPC32XX_RTC_CTRL); |
| rtc_writel(rtc, LPC32XX_RTC_CTRL, tmp | LPC32XX_RTC_CTRL_CNTR_DIS); |
| rtc_writel(rtc, LPC32XX_RTC_UCOUNT, secs); |
| rtc_writel(rtc, LPC32XX_RTC_DCOUNT, 0xFFFFFFFF - secs); |
| rtc_writel(rtc, LPC32XX_RTC_CTRL, tmp &= ~LPC32XX_RTC_CTRL_CNTR_DIS); |
| |
| spin_unlock_irq(&rtc->lock); |
| |
| return 0; |
| } |
| |
| static int lpc32xx_rtc_read_alarm(struct device *dev, |
| struct rtc_wkalrm *wkalrm) |
| { |
| struct lpc32xx_rtc *rtc = dev_get_drvdata(dev); |
| |
| rtc_time_to_tm(rtc_readl(rtc, LPC32XX_RTC_MATCH0), &wkalrm->time); |
| wkalrm->enabled = rtc->alarm_enabled; |
| wkalrm->pending = !!(rtc_readl(rtc, LPC32XX_RTC_INTSTAT) & |
| LPC32XX_RTC_INTSTAT_MATCH0); |
| |
| return rtc_valid_tm(&wkalrm->time); |
| } |
| |
| static int lpc32xx_rtc_set_alarm(struct device *dev, |
| struct rtc_wkalrm *wkalrm) |
| { |
| struct lpc32xx_rtc *rtc = dev_get_drvdata(dev); |
| unsigned long alarmsecs; |
| u32 tmp; |
| int ret; |
| |
| ret = rtc_tm_to_time(&wkalrm->time, &alarmsecs); |
| if (ret < 0) { |
| dev_warn(dev, "Failed to convert time: %d\n", ret); |
| return ret; |
| } |
| |
| spin_lock_irq(&rtc->lock); |
| |
| /* Disable alarm during update */ |
| tmp = rtc_readl(rtc, LPC32XX_RTC_CTRL); |
| rtc_writel(rtc, LPC32XX_RTC_CTRL, tmp & ~LPC32XX_RTC_CTRL_MATCH0); |
| |
| rtc_writel(rtc, LPC32XX_RTC_MATCH0, alarmsecs); |
| |
| rtc->alarm_enabled = wkalrm->enabled; |
| if (wkalrm->enabled) { |
| rtc_writel(rtc, LPC32XX_RTC_INTSTAT, |
| LPC32XX_RTC_INTSTAT_MATCH0); |
| rtc_writel(rtc, LPC32XX_RTC_CTRL, tmp | |
| LPC32XX_RTC_CTRL_MATCH0); |
| } |
| |
| spin_unlock_irq(&rtc->lock); |
| |
| return 0; |
| } |
| |
| static int lpc32xx_rtc_alarm_irq_enable(struct device *dev, |
| unsigned int enabled) |
| { |
| struct lpc32xx_rtc *rtc = dev_get_drvdata(dev); |
| u32 tmp; |
| |
| spin_lock_irq(&rtc->lock); |
| tmp = rtc_readl(rtc, LPC32XX_RTC_CTRL); |
| |
| if (enabled) { |
| rtc->alarm_enabled = 1; |
| tmp |= LPC32XX_RTC_CTRL_MATCH0; |
| } else { |
| rtc->alarm_enabled = 0; |
| tmp &= ~LPC32XX_RTC_CTRL_MATCH0; |
| } |
| |
| rtc_writel(rtc, LPC32XX_RTC_CTRL, tmp); |
| spin_unlock_irq(&rtc->lock); |
| |
| return 0; |
| } |
| |
| static irqreturn_t lpc32xx_rtc_alarm_interrupt(int irq, void *dev) |
| { |
| struct lpc32xx_rtc *rtc = dev; |
| |
| spin_lock(&rtc->lock); |
| |
| /* Disable alarm interrupt */ |
| rtc_writel(rtc, LPC32XX_RTC_CTRL, |
| rtc_readl(rtc, LPC32XX_RTC_CTRL) & |
| ~LPC32XX_RTC_CTRL_MATCH0); |
| rtc->alarm_enabled = 0; |
| |
| /* |
| * Write a large value to the match value so the RTC won't |
| * keep firing the match status |
| */ |
| rtc_writel(rtc, LPC32XX_RTC_MATCH0, 0xFFFFFFFF); |
| rtc_writel(rtc, LPC32XX_RTC_INTSTAT, LPC32XX_RTC_INTSTAT_MATCH0); |
| |
| spin_unlock(&rtc->lock); |
| |
| rtc_update_irq(rtc->rtc, 1, RTC_IRQF | RTC_AF); |
| |
| return IRQ_HANDLED; |
| } |
| |
| static const struct rtc_class_ops lpc32xx_rtc_ops = { |
| .read_time = lpc32xx_rtc_read_time, |
| .set_mmss = lpc32xx_rtc_set_mmss, |
| .read_alarm = lpc32xx_rtc_read_alarm, |
| .set_alarm = lpc32xx_rtc_set_alarm, |
| .alarm_irq_enable = lpc32xx_rtc_alarm_irq_enable, |
| }; |
| |
| static int __devinit lpc32xx_rtc_probe(struct platform_device *pdev) |
| { |
| struct resource *res; |
| struct lpc32xx_rtc *rtc; |
| resource_size_t size; |
| int rtcirq; |
| u32 tmp; |
| |
| res = platform_get_resource(pdev, IORESOURCE_MEM, 0); |
| if (!res) { |
| dev_err(&pdev->dev, "Can't get memory resource\n"); |
| return -ENOENT; |
| } |
| |
| rtcirq = platform_get_irq(pdev, 0); |
| if (rtcirq < 0 || rtcirq >= NR_IRQS) { |
| dev_warn(&pdev->dev, "Can't get interrupt resource\n"); |
| rtcirq = -1; |
| } |
| |
| rtc = devm_kzalloc(&pdev->dev, sizeof(*rtc), GFP_KERNEL); |
| if (unlikely(!rtc)) { |
| dev_err(&pdev->dev, "Can't allocate memory\n"); |
| return -ENOMEM; |
| } |
| rtc->irq = rtcirq; |
| |
| size = resource_size(res); |
| |
| if (!devm_request_mem_region(&pdev->dev, res->start, size, |
| pdev->name)) { |
| dev_err(&pdev->dev, "RTC registers are not free\n"); |
| return -EBUSY; |
| } |
| |
| rtc->rtc_base = devm_ioremap(&pdev->dev, res->start, size); |
| if (!rtc->rtc_base) { |
| dev_err(&pdev->dev, "Can't map memory\n"); |
| return -ENOMEM; |
| } |
| |
| spin_lock_init(&rtc->lock); |
| |
| /* |
| * The RTC is on a separate power domain and can keep it's state |
| * across a chip power cycle. If the RTC has never been previously |
| * setup, then set it up now for the first time. |
| */ |
| tmp = rtc_readl(rtc, LPC32XX_RTC_CTRL); |
| if (rtc_readl(rtc, LPC32XX_RTC_KEY) != LPC32XX_RTC_KEY_ONSW_LOADVAL) { |
| tmp &= ~(LPC32XX_RTC_CTRL_SW_RESET | |
| LPC32XX_RTC_CTRL_CNTR_DIS | |
| LPC32XX_RTC_CTRL_MATCH0 | |
| LPC32XX_RTC_CTRL_MATCH1 | |
| LPC32XX_RTC_CTRL_ONSW_MATCH0 | |
| LPC32XX_RTC_CTRL_ONSW_MATCH1 | |
| LPC32XX_RTC_CTRL_ONSW_FORCE_HI); |
| rtc_writel(rtc, LPC32XX_RTC_CTRL, tmp); |
| |
| /* Clear latched interrupt states */ |
| rtc_writel(rtc, LPC32XX_RTC_MATCH0, 0xFFFFFFFF); |
| rtc_writel(rtc, LPC32XX_RTC_INTSTAT, |
| LPC32XX_RTC_INTSTAT_MATCH0 | |
| LPC32XX_RTC_INTSTAT_MATCH1 | |
| LPC32XX_RTC_INTSTAT_ONSW); |
| |
| /* Write key value to RTC so it won't reload on reset */ |
| rtc_writel(rtc, LPC32XX_RTC_KEY, |
| LPC32XX_RTC_KEY_ONSW_LOADVAL); |
| } else { |
| rtc_writel(rtc, LPC32XX_RTC_CTRL, |
| tmp & ~LPC32XX_RTC_CTRL_MATCH0); |
| } |
| |
| platform_set_drvdata(pdev, rtc); |
| |
| rtc->rtc = rtc_device_register(RTC_NAME, &pdev->dev, &lpc32xx_rtc_ops, |
| THIS_MODULE); |
| if (IS_ERR(rtc->rtc)) { |
| dev_err(&pdev->dev, "Can't get RTC\n"); |
| platform_set_drvdata(pdev, NULL); |
| return PTR_ERR(rtc->rtc); |
| } |
| |
| /* |
| * IRQ is enabled after device registration in case alarm IRQ |
| * is pending upon suspend exit. |
| */ |
| if (rtc->irq >= 0) { |
| if (devm_request_irq(&pdev->dev, rtc->irq, |
| lpc32xx_rtc_alarm_interrupt, |
| IRQF_DISABLED, pdev->name, rtc) < 0) { |
| dev_warn(&pdev->dev, "Can't request interrupt.\n"); |
| rtc->irq = -1; |
| } else { |
| device_init_wakeup(&pdev->dev, 1); |
| } |
| } |
| |
| return 0; |
| } |
| |
| static int __devexit lpc32xx_rtc_remove(struct platform_device *pdev) |
| { |
| struct lpc32xx_rtc *rtc = platform_get_drvdata(pdev); |
| |
| if (rtc->irq >= 0) |
| device_init_wakeup(&pdev->dev, 0); |
| |
| platform_set_drvdata(pdev, NULL); |
| rtc_device_unregister(rtc->rtc); |
| |
| return 0; |
| } |
| |
| #ifdef CONFIG_PM |
| static int lpc32xx_rtc_suspend(struct device *dev) |
| { |
| struct platform_device *pdev = to_platform_device(dev); |
| struct lpc32xx_rtc *rtc = platform_get_drvdata(pdev); |
| |
| if (rtc->irq >= 0) { |
| if (device_may_wakeup(&pdev->dev)) |
| enable_irq_wake(rtc->irq); |
| else |
| disable_irq_wake(rtc->irq); |
| } |
| |
| return 0; |
| } |
| |
| static int lpc32xx_rtc_resume(struct device *dev) |
| { |
| struct platform_device *pdev = to_platform_device(dev); |
| struct lpc32xx_rtc *rtc = platform_get_drvdata(pdev); |
| |
| if (rtc->irq >= 0 && device_may_wakeup(&pdev->dev)) |
| disable_irq_wake(rtc->irq); |
| |
| return 0; |
| } |
| |
| /* Unconditionally disable the alarm */ |
| static int lpc32xx_rtc_freeze(struct device *dev) |
| { |
| struct platform_device *pdev = to_platform_device(dev); |
| struct lpc32xx_rtc *rtc = platform_get_drvdata(pdev); |
| |
| spin_lock_irq(&rtc->lock); |
| |
| rtc_writel(rtc, LPC32XX_RTC_CTRL, |
| rtc_readl(rtc, LPC32XX_RTC_CTRL) & |
| ~LPC32XX_RTC_CTRL_MATCH0); |
| |
| spin_unlock_irq(&rtc->lock); |
| |
| return 0; |
| } |
| |
| static int lpc32xx_rtc_thaw(struct device *dev) |
| { |
| struct platform_device *pdev = to_platform_device(dev); |
| struct lpc32xx_rtc *rtc = platform_get_drvdata(pdev); |
| |
| if (rtc->alarm_enabled) { |
| spin_lock_irq(&rtc->lock); |
| |
| rtc_writel(rtc, LPC32XX_RTC_CTRL, |
| rtc_readl(rtc, LPC32XX_RTC_CTRL) | |
| LPC32XX_RTC_CTRL_MATCH0); |
| |
| spin_unlock_irq(&rtc->lock); |
| } |
| |
| return 0; |
| } |
| |
| static const struct dev_pm_ops lpc32xx_rtc_pm_ops = { |
| .suspend = lpc32xx_rtc_suspend, |
| .resume = lpc32xx_rtc_resume, |
| .freeze = lpc32xx_rtc_freeze, |
| .thaw = lpc32xx_rtc_thaw, |
| .restore = lpc32xx_rtc_resume |
| }; |
| |
| #define LPC32XX_RTC_PM_OPS (&lpc32xx_rtc_pm_ops) |
| #else |
| #define LPC32XX_RTC_PM_OPS NULL |
| #endif |
| |
| static struct platform_driver lpc32xx_rtc_driver = { |
| .probe = lpc32xx_rtc_probe, |
| .remove = __devexit_p(lpc32xx_rtc_remove), |
| .driver = { |
| .name = RTC_NAME, |
| .owner = THIS_MODULE, |
| .pm = LPC32XX_RTC_PM_OPS |
| }, |
| }; |
| |
| module_platform_driver(lpc32xx_rtc_driver); |
| |
| MODULE_AUTHOR("Kevin Wells <wellsk40@gmail.com"); |
| MODULE_DESCRIPTION("RTC driver for the LPC32xx SoC"); |
| MODULE_LICENSE("GPL"); |
| MODULE_ALIAS("platform:rtc-lpc32xx"); |