1 // SPDX-License-Identifier: GPL-2.0
3  * Real Time Clock (RTC) Driver for i.MX53
4  * Copyright (c) 2004-2011 Freescale Semiconductor, Inc.
14 #include <linux/rtc.h>
26 #define SRTC_LPSR_NVES        BIT(14)	/* lp non-valid state exit status */
40 	struct rtc_device *rtc;  member
51  * The caller should hold the pdata->lock
63 			if (!--timeout) {  in mxc_rtc_sync_lp_locked()
71 /* This function is the RTC interrupt service routine. */
76 	void __iomem *ioaddr = pdata->ioaddr;  in mxc_rtc_interrupt()
81 	spin_lock_irqsave(&pdata->lock, flags);  in mxc_rtc_interrupt()
82 	if (clk_enable(pdata->clk)) {  in mxc_rtc_interrupt()
83 		spin_unlock_irqrestore(&pdata->lock, flags);  in mxc_rtc_interrupt()
93 			rtc_update_irq(pdata->rtc, 1, RTC_AF | RTC_IRQF);  in mxc_rtc_interrupt()
106 	clk_disable(pdata->clk);  in mxc_rtc_interrupt()
107 	spin_unlock_irqrestore(&pdata->lock, flags);  in mxc_rtc_interrupt()
113  * @return  0 if successful; non-zero otherwise.
119 	spin_lock_irq(&pdata->lock);  in mxc_rtc_lock()
120 	ret = clk_enable(pdata->clk);  in mxc_rtc_lock()
122 		spin_unlock_irq(&pdata->lock);  in mxc_rtc_lock()
130 	clk_disable(pdata->clk);  in mxc_rtc_unlock()
131 	spin_unlock_irq(&pdata->lock);  in mxc_rtc_unlock()
136  * This function reads the current RTC time into tm in Gregorian date.
138  * @param  tm           contains the RTC time value upon return
140  * @return  0 if successful; non-zero otherwise.
145 	const int clk_failed = clk_enable(pdata->clk);  in mxc_rtc_read_time()
148 		const time64_t now = readl(pdata->ioaddr + SRTC_LPSCMR);  in mxc_rtc_read_time()
151 		clk_disable(pdata->clk);  in mxc_rtc_read_time()
158  * This function sets the internal RTC time based on tm in Gregorian date.
160  * @param  tm           the time value to be set in the RTC
162  * @return  0 if successful; non-zero otherwise.
174 	writel(time, pdata->ioaddr + SRTC_LPSCMR);  in mxc_rtc_set_time()
175 	mxc_rtc_sync_lp_locked(dev, pdata->ioaddr);  in mxc_rtc_set_time()
184  * @param  alrm         contains the RTC alarm value upon return
186  * @return  0 if successful; non-zero otherwise.
191 	void __iomem *ioaddr = pdata->ioaddr;  in mxc_rtc_read_alarm()
198 	rtc_time64_to_tm(readl(ioaddr + SRTC_LPSAR), &alrm->time);  in mxc_rtc_read_alarm()
199 	alrm->pending = !!(readl(ioaddr + SRTC_LPSR) & SRTC_LPSR_ALP);  in mxc_rtc_read_alarm()
205  * The caller should hold the pdata->lock
210 	u32 lp_cr = readl(pdata->ioaddr + SRTC_LPCR);  in mxc_rtc_alarm_irq_enable_locked()
217 	writel(lp_cr, pdata->ioaddr + SRTC_LPCR);  in mxc_rtc_alarm_irq_enable_locked()
233  * This function sets the RTC alarm based on passed in alrm.
235  * @param  alrm         the alarm value to be set in the RTC
237  * @return  0 if successful; non-zero otherwise.
241 	const time64_t time = rtc_tm_to_time64(&alrm->time);  in mxc_rtc_set_alarm()
248 	writel((u32)time, pdata->ioaddr + SRTC_LPSAR);  in mxc_rtc_set_alarm()
251 	writel(SRTC_LPSR_ALP, pdata->ioaddr + SRTC_LPSR);  in mxc_rtc_set_alarm()
252 	mxc_rtc_sync_lp_locked(dev, pdata->ioaddr);  in mxc_rtc_set_alarm()
254 	mxc_rtc_alarm_irq_enable_locked(pdata, alrm->enabled);  in mxc_rtc_set_alarm()
255 	mxc_rtc_sync_lp_locked(dev, pdata->ioaddr);  in mxc_rtc_set_alarm()
273 		if (!--timeout)  in mxc_rtc_wait_for_flag()
274 			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()
289 	pdata->ioaddr = devm_platform_ioremap_resource(pdev, 0);  in mxc_rtc_probe()
290 	if (IS_ERR(pdata->ioaddr))  in mxc_rtc_probe()
291 		return PTR_ERR(pdata->ioaddr);  in mxc_rtc_probe()
293 	ioaddr = pdata->ioaddr;  in mxc_rtc_probe()
295 	pdata->clk = devm_clk_get(&pdev->dev, NULL);  in mxc_rtc_probe()
296 	if (IS_ERR(pdata->clk)) {  in mxc_rtc_probe()
297 		dev_err(&pdev->dev, "unable to get rtc clock!\n");  in mxc_rtc_probe()
298 		return PTR_ERR(pdata->clk);  in mxc_rtc_probe()
301 	spin_lock_init(&pdata->lock);  in mxc_rtc_probe()
302 	pdata->irq = platform_get_irq(pdev, 0);  in mxc_rtc_probe()
303 	if (pdata->irq < 0)  in mxc_rtc_probe()
304 		return pdata->irq;  in mxc_rtc_probe()
306 	device_init_wakeup(&pdev->dev, 1);  in mxc_rtc_probe()
307 	ret = dev_pm_set_wake_irq(&pdev->dev, pdata->irq);  in mxc_rtc_probe()
309 		dev_err(&pdev->dev, "failed to enable irq wake\n");  in mxc_rtc_probe()
311 	ret = clk_prepare_enable(pdata->clk);  in mxc_rtc_probe()
324 		dev_err(&pdev->dev, "Timeout waiting for SRTC_LPSR_IES\n");  in mxc_rtc_probe()
325 		clk_disable_unprepare(pdata->clk);  in mxc_rtc_probe()
329 	/* move out of non-valid state */  in mxc_rtc_probe()
334 		dev_err(&pdev->dev, "Timeout waiting for SRTC_LPSR_NVES\n");  in mxc_rtc_probe()
335 		clk_disable_unprepare(pdata->clk);  in mxc_rtc_probe()
339 	pdata->rtc = devm_rtc_allocate_device(&pdev->dev);  in mxc_rtc_probe()
340 	if (IS_ERR(pdata->rtc))  in mxc_rtc_probe()
341 		return PTR_ERR(pdata->rtc);  in mxc_rtc_probe()
343 	pdata->rtc->ops = &mxc_rtc_ops;  in mxc_rtc_probe()
344 	pdata->rtc->range_max = U32_MAX;  in mxc_rtc_probe()
346 	clk_disable(pdata->clk);  in mxc_rtc_probe()
349 	    devm_request_irq(&pdev->dev, pdata->irq, mxc_rtc_interrupt, 0,  in mxc_rtc_probe()
350 			     pdev->name, &pdev->dev);  in mxc_rtc_probe()
352 		dev_err(&pdev->dev, "interrupt not available.\n");  in mxc_rtc_probe()
353 		clk_unprepare(pdata->clk);  in mxc_rtc_probe()
357 	ret = rtc_register_device(pdata->rtc);  in mxc_rtc_probe()
359 		clk_unprepare(pdata->clk);  in mxc_rtc_probe()
368 	clk_disable_unprepare(pdata->clk);  in mxc_rtc_remove()
373 	{ .compatible = "fsl,imx53-rtc", },
389 MODULE_DESCRIPTION("Real Time Clock (RTC) Driver for i.MX53");