1 // SPDX-License-Identifier: GPL-2.0
3  * Real Time Clock (RTC) Driver for i.MX53
4  * Copyright (c) 2004-2011 Freescale Semiconductor, Inc.
13 #include <linux/rtc.h>
25 #define SRTC_LPSR_NVES        BIT(14)	/* lp non-valid state exit status */
39 	struct rtc_device *rtc;  member
50  * The caller should hold the pdata->lock
62 			if (!--timeout) {  in mxc_rtc_sync_lp_locked()
70 /* This function is the RTC interrupt service routine. */
75 	void __iomem *ioaddr = pdata->ioaddr;  in mxc_rtc_interrupt()
80 	spin_lock_irqsave(&pdata->lock, flags);  in mxc_rtc_interrupt()
81 	if (clk_enable(pdata->clk)) {  in mxc_rtc_interrupt()
82 		spin_unlock_irqrestore(&pdata->lock, flags);  in mxc_rtc_interrupt()
92 			rtc_update_irq(pdata->rtc, 1, RTC_AF | RTC_IRQF);  in mxc_rtc_interrupt()
105 	clk_disable(pdata->clk);  in mxc_rtc_interrupt()
106 	spin_unlock_irqrestore(&pdata->lock, flags);  in mxc_rtc_interrupt()
112  * @return  0 if successful; non-zero otherwise.
118 	spin_lock_irq(&pdata->lock);  in mxc_rtc_lock()
119 	ret = clk_enable(pdata->clk);  in mxc_rtc_lock()
121 		spin_unlock_irq(&pdata->lock);  in mxc_rtc_lock()
129 	clk_disable(pdata->clk);  in mxc_rtc_unlock()
130 	spin_unlock_irq(&pdata->lock);  in mxc_rtc_unlock()
135  * This function reads the current RTC time into tm in Gregorian date.
137  * @param  tm           contains the RTC time value upon return
139  * @return  0 if successful; non-zero otherwise.
144 	const int clk_failed = clk_enable(pdata->clk);  in mxc_rtc_read_time()
147 		const time64_t now = readl(pdata->ioaddr + SRTC_LPSCMR);  in mxc_rtc_read_time()
150 		clk_disable(pdata->clk);  in mxc_rtc_read_time()
157  * This function sets the internal RTC time based on tm in Gregorian date.
159  * @param  tm           the time value to be set in the RTC
161  * @return  0 if successful; non-zero otherwise.
173 	writel(time, pdata->ioaddr + SRTC_LPSCMR);  in mxc_rtc_set_time()
174 	mxc_rtc_sync_lp_locked(dev, pdata->ioaddr);  in mxc_rtc_set_time()
183  * @param  alrm         contains the RTC alarm value upon return
185  * @return  0 if successful; non-zero otherwise.
190 	void __iomem *ioaddr = pdata->ioaddr;  in mxc_rtc_read_alarm()
197 	rtc_time64_to_tm(readl(ioaddr + SRTC_LPSAR), &alrm->time);  in mxc_rtc_read_alarm()
198 	alrm->pending = !!(readl(ioaddr + SRTC_LPSR) & SRTC_LPSR_ALP);  in mxc_rtc_read_alarm()
204  * The caller should hold the pdata->lock
209 	u32 lp_cr = readl(pdata->ioaddr + SRTC_LPCR);  in mxc_rtc_alarm_irq_enable_locked()
216 	writel(lp_cr, pdata->ioaddr + SRTC_LPCR);  in mxc_rtc_alarm_irq_enable_locked()
232  * This function sets the RTC alarm based on passed in alrm.
234  * @param  alrm         the alarm value to be set in the RTC
236  * @return  0 if successful; non-zero otherwise.
240 	const time64_t time = rtc_tm_to_time64(&alrm->time);  in mxc_rtc_set_alarm()
247 	writel((u32)time, pdata->ioaddr + SRTC_LPSAR);  in mxc_rtc_set_alarm()
250 	writel(SRTC_LPSR_ALP, pdata->ioaddr + SRTC_LPSR);  in mxc_rtc_set_alarm()
251 	mxc_rtc_sync_lp_locked(dev, pdata->ioaddr);  in mxc_rtc_set_alarm()
253 	mxc_rtc_alarm_irq_enable_locked(pdata, alrm->enabled);  in mxc_rtc_set_alarm()
254 	mxc_rtc_sync_lp_locked(dev, pdata->ioaddr);  in mxc_rtc_set_alarm()
272 		if (!--timeout)  in mxc_rtc_wait_for_flag()
273 			return -EBUSY;  in mxc_rtc_wait_for_flag()
285 	pdata = devm_kzalloc(&pdev->dev, sizeof(*pdata), GFP_KERNEL);  in mxc_rtc_probe()
287 		return -ENOMEM;  in mxc_rtc_probe()
290 	pdata->ioaddr = devm_ioremap_resource(&pdev->dev, res);  in mxc_rtc_probe()
291 	if (IS_ERR(pdata->ioaddr))  in mxc_rtc_probe()
292 		return PTR_ERR(pdata->ioaddr);  in mxc_rtc_probe()
294 	ioaddr = pdata->ioaddr;  in mxc_rtc_probe()
296 	pdata->clk = devm_clk_get(&pdev->dev, NULL);  in mxc_rtc_probe()
297 	if (IS_ERR(pdata->clk)) {  in mxc_rtc_probe()
298 		dev_err(&pdev->dev, "unable to get rtc clock!\n");  in mxc_rtc_probe()
299 		return PTR_ERR(pdata->clk);  in mxc_rtc_probe()
302 	spin_lock_init(&pdata->lock);  in mxc_rtc_probe()
303 	pdata->irq = platform_get_irq(pdev, 0);  in mxc_rtc_probe()
304 	if (pdata->irq < 0)  in mxc_rtc_probe()
305 		return pdata->irq;  in mxc_rtc_probe()
307 	device_init_wakeup(&pdev->dev, 1);  in mxc_rtc_probe()
309 	ret = clk_prepare_enable(pdata->clk);  in mxc_rtc_probe()
322 		dev_err(&pdev->dev, "Timeout waiting for SRTC_LPSR_IES\n");  in mxc_rtc_probe()
323 		clk_disable_unprepare(pdata->clk);  in mxc_rtc_probe()
327 	/* move out of non-valid state */  in mxc_rtc_probe()
332 		dev_err(&pdev->dev, "Timeout waiting for SRTC_LPSR_NVES\n");  in mxc_rtc_probe()
333 		clk_disable_unprepare(pdata->clk);  in mxc_rtc_probe()
337 	pdata->rtc = devm_rtc_allocate_device(&pdev->dev);  in mxc_rtc_probe()
338 	if (IS_ERR(pdata->rtc))  in mxc_rtc_probe()
339 		return PTR_ERR(pdata->rtc);  in mxc_rtc_probe()
341 	pdata->rtc->ops = &mxc_rtc_ops;  in mxc_rtc_probe()
342 	pdata->rtc->range_max = U32_MAX;  in mxc_rtc_probe()
344 	clk_disable(pdata->clk);  in mxc_rtc_probe()
347 	    devm_request_irq(&pdev->dev, pdata->irq, mxc_rtc_interrupt, 0,  in mxc_rtc_probe()
348 			     pdev->name, &pdev->dev);  in mxc_rtc_probe()
350 		dev_err(&pdev->dev, "interrupt not available.\n");  in mxc_rtc_probe()
351 		clk_unprepare(pdata->clk);  in mxc_rtc_probe()
355 	ret = rtc_register_device(pdata->rtc);  in mxc_rtc_probe()
357 		clk_unprepare(pdata->clk);  in mxc_rtc_probe()
366 	clk_disable_unprepare(pdata->clk);  in mxc_rtc_remove()
376 		enable_irq_wake(pdata->irq);  in mxc_rtc_suspend()
386 		disable_irq_wake(pdata->irq);  in mxc_rtc_resume()
395 	{ .compatible = "fsl,imx53-rtc", },
412 MODULE_DESCRIPTION("Real Time Clock (RTC) Driver for i.MX53");