3  * rtc-st-lpc.c - ST's LPC RTC, powered by the Low Power Timer
23 #include <linux/rtc.h>
52 static void st_rtc_set_hw_alarm(struct st_rtc *rtc,  in st_rtc_set_hw_alarm()  argument
57 	spin_lock_irqsave(&rtc->lock, flags);  in st_rtc_set_hw_alarm()
59 	writel_relaxed(1, rtc->ioaddr + LPC_WDT_OFF);  in st_rtc_set_hw_alarm()
61 	writel_relaxed(msb, rtc->ioaddr + LPC_LPA_MSB_OFF);  in st_rtc_set_hw_alarm()
62 	writel_relaxed(lsb, rtc->ioaddr + LPC_LPA_LSB_OFF);  in st_rtc_set_hw_alarm()
63 	writel_relaxed(1, rtc->ioaddr + LPC_LPA_START_OFF);  in st_rtc_set_hw_alarm()
65 	writel_relaxed(0, rtc->ioaddr + LPC_WDT_OFF);  in st_rtc_set_hw_alarm()
67 	spin_unlock_irqrestore(&rtc->lock, flags);  in st_rtc_set_hw_alarm()
72 	struct st_rtc *rtc = (struct st_rtc *)data;  in st_rtc_handler()  local
74 	rtc_update_irq(rtc->rtc_dev, 1, RTC_AF);  in st_rtc_handler()
81 	struct st_rtc *rtc = dev_get_drvdata(dev);  in st_rtc_read_time()  local
86 	spin_lock_irqsave(&rtc->lock, flags);  in st_rtc_read_time()
89 		lpt_msb = readl_relaxed(rtc->ioaddr + LPC_LPT_MSB_OFF);  in st_rtc_read_time()
90 		lpt_lsb = readl_relaxed(rtc->ioaddr + LPC_LPT_LSB_OFF);  in st_rtc_read_time()
91 	} while (readl_relaxed(rtc->ioaddr + LPC_LPT_MSB_OFF) != lpt_msb);  in st_rtc_read_time()
93 	spin_unlock_irqrestore(&rtc->lock, flags);  in st_rtc_read_time()
96 	do_div(lpt, rtc->clkrate);  in st_rtc_read_time()
104 	struct st_rtc *rtc = dev_get_drvdata(dev);  in st_rtc_set_time()  local
110 	lpt = (unsigned long long)secs * rtc->clkrate;  in st_rtc_set_time()
112 	spin_lock_irqsave(&rtc->lock, flags);  in st_rtc_set_time()
114 	writel_relaxed(lpt >> 32, rtc->ioaddr + LPC_LPT_MSB_OFF);  in st_rtc_set_time()
115 	writel_relaxed(lpt, rtc->ioaddr + LPC_LPT_LSB_OFF);  in st_rtc_set_time()
116 	writel_relaxed(1, rtc->ioaddr + LPC_LPT_START_OFF);  in st_rtc_set_time()
118 	spin_unlock_irqrestore(&rtc->lock, flags);  in st_rtc_set_time()
125 	struct st_rtc *rtc = dev_get_drvdata(dev);  in st_rtc_read_alarm()  local
128 	spin_lock_irqsave(&rtc->lock, flags);  in st_rtc_read_alarm()
130 	memcpy(wkalrm, &rtc->alarm, sizeof(struct rtc_wkalrm));  in st_rtc_read_alarm()
132 	spin_unlock_irqrestore(&rtc->lock, flags);  in st_rtc_read_alarm()
139 	struct st_rtc *rtc = dev_get_drvdata(dev);  in st_rtc_alarm_irq_enable()  local
141 	if (enabled && !rtc->irq_enabled) {  in st_rtc_alarm_irq_enable()
142 		enable_irq(rtc->irq);  in st_rtc_alarm_irq_enable()
143 		rtc->irq_enabled = true;  in st_rtc_alarm_irq_enable()
144 	} else if (!enabled && rtc->irq_enabled) {  in st_rtc_alarm_irq_enable()
145 		disable_irq(rtc->irq);  in st_rtc_alarm_irq_enable()
146 		rtc->irq_enabled = false;  in st_rtc_alarm_irq_enable()
154 	struct st_rtc *rtc = dev_get_drvdata(dev);  in st_rtc_set_alarm()  local
164 	memcpy(&rtc->alarm, t, sizeof(struct rtc_wkalrm));  in st_rtc_set_alarm()
168 	lpa = (unsigned long long)alarm_secs * rtc->clkrate;  in st_rtc_set_alarm()
170 	st_rtc_set_hw_alarm(rtc, lpa >> 32, lpa);  in st_rtc_set_alarm()
187 	struct st_rtc *rtc;  in st_rtc_probe()  local
197 	/* LPC can either run as a Clocksource or in RTC or WDT mode */  in st_rtc_probe()
201 	rtc = devm_kzalloc(&pdev->dev, sizeof(struct st_rtc), GFP_KERNEL);  in st_rtc_probe()
202 	if (!rtc)  in st_rtc_probe()
205 	rtc->rtc_dev = devm_rtc_allocate_device(&pdev->dev);  in st_rtc_probe()
206 	if (IS_ERR(rtc->rtc_dev))  in st_rtc_probe()
207 		return PTR_ERR(rtc->rtc_dev);  in st_rtc_probe()
209 	spin_lock_init(&rtc->lock);  in st_rtc_probe()
211 	rtc->ioaddr = devm_platform_ioremap_resource(pdev, 0);  in st_rtc_probe()
212 	if (IS_ERR(rtc->ioaddr))  in st_rtc_probe()
213 		return PTR_ERR(rtc->ioaddr);  in st_rtc_probe()
215 	rtc->irq = irq_of_parse_and_map(np, 0);  in st_rtc_probe()
216 	if (!rtc->irq) {  in st_rtc_probe()
221 	ret = devm_request_irq(&pdev->dev, rtc->irq, st_rtc_handler, 0,  in st_rtc_probe()
222 			       pdev->name, rtc);  in st_rtc_probe()
224 		dev_err(&pdev->dev, "Failed to request irq %i\n", rtc->irq);  in st_rtc_probe()
228 	enable_irq_wake(rtc->irq);  in st_rtc_probe()
229 	disable_irq(rtc->irq);  in st_rtc_probe()
231 	rtc->clk = devm_clk_get_enabled(&pdev->dev, NULL);  in st_rtc_probe()
232 	if (IS_ERR(rtc->clk))  in st_rtc_probe()
233 		return dev_err_probe(&pdev->dev, PTR_ERR(rtc->clk),  in st_rtc_probe()
236 	rtc->clkrate = clk_get_rate(rtc->clk);  in st_rtc_probe()
237 	if (!rtc->clkrate) {  in st_rtc_probe()
244 	platform_set_drvdata(pdev, rtc);  in st_rtc_probe()
246 	rtc->rtc_dev->ops = &st_rtc_ops;  in st_rtc_probe()
247 	rtc->rtc_dev->range_max = U64_MAX;  in st_rtc_probe()
248 	do_div(rtc->rtc_dev->range_max, rtc->clkrate);  in st_rtc_probe()
250 	ret = devm_rtc_register_device(rtc->rtc_dev);  in st_rtc_probe()
260 	struct st_rtc *rtc = dev_get_drvdata(dev);  in st_rtc_suspend()  local
265 	writel_relaxed(1, rtc->ioaddr + LPC_WDT_OFF);  in st_rtc_suspend()
266 	writel_relaxed(0, rtc->ioaddr + LPC_LPA_START_OFF);  in st_rtc_suspend()
267 	writel_relaxed(0, rtc->ioaddr + LPC_WDT_OFF);  in st_rtc_suspend()
274 	struct st_rtc *rtc = dev_get_drvdata(dev);  in st_rtc_resume()  local
276 	rtc_alarm_irq_enable(rtc->rtc_dev, 0);  in st_rtc_resume()
279 	 * clean 'rtc->alarm' to allow a new  in st_rtc_resume()
280 	 * .set_alarm to the upper RTC layer  in st_rtc_resume()
282 	memset(&rtc->alarm, 0, sizeof(struct rtc_wkalrm));  in st_rtc_resume()
284 	writel_relaxed(0, rtc->ioaddr + LPC_LPA_MSB_OFF);  in st_rtc_resume()
285 	writel_relaxed(0, rtc->ioaddr + LPC_LPA_LSB_OFF);  in st_rtc_resume()
286 	writel_relaxed(1, rtc->ioaddr + LPC_WDT_OFF);  in st_rtc_resume()
287 	writel_relaxed(1, rtc->ioaddr + LPC_LPA_START_OFF);  in st_rtc_resume()
288 	writel_relaxed(0, rtc->ioaddr + LPC_WDT_OFF);  in st_rtc_resume()
304 		.name = "st-lpc-rtc",
313 MODULE_DESCRIPTION("STMicroelectronics LPC RTC driver");