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v6.2
  1// SPDX-License-Identifier: GPL-2.0-or-later
  2/*
  3 * Real Time Clock interface for StrongARM SA1x00 and XScale PXA2xx
  4 *
  5 * Copyright (c) 2000 Nils Faerber
  6 *
  7 * Based on rtc.c by Paul Gortmaker
  8 *
  9 * Original Driver by Nils Faerber <nils@kernelconcepts.de>
 10 *
 11 * Modifications from:
 12 *   CIH <cih@coventive.com>
 13 *   Nicolas Pitre <nico@fluxnic.net>
 14 *   Andrew Christian <andrew.christian@hp.com>
 15 *
 16 * Converted to the RTC subsystem and Driver Model
 17 *   by Richard Purdie <rpurdie@rpsys.net>
 
 
 
 
 
 18 */
 19
 20#include <linux/platform_device.h>
 21#include <linux/module.h>
 22#include <linux/clk.h>
 23#include <linux/rtc.h>
 24#include <linux/init.h>
 25#include <linux/fs.h>
 26#include <linux/interrupt.h>
 27#include <linux/slab.h>
 28#include <linux/string.h>
 29#include <linux/of.h>
 30#include <linux/pm.h>
 31#include <linux/bitops.h>
 32#include <linux/io.h>
 33
 34#define RTSR_HZE		BIT(3)	/* HZ interrupt enable */
 35#define RTSR_ALE		BIT(2)	/* RTC alarm interrupt enable */
 36#define RTSR_HZ			BIT(1)	/* HZ rising-edge detected */
 37#define RTSR_AL			BIT(0)	/* RTC alarm detected */
 38
 39#include "rtc-sa1100.h"
 
 
 40
 41#define RTC_DEF_DIVIDER		(32768 - 1)
 42#define RTC_DEF_TRIM		0
 43#define RTC_FREQ		1024
 44
 
 
 
 
 
 
 
 45
 46static irqreturn_t sa1100_rtc_interrupt(int irq, void *dev_id)
 47{
 48	struct sa1100_rtc *info = dev_get_drvdata(dev_id);
 49	struct rtc_device *rtc = info->rtc;
 50	unsigned int rtsr;
 51	unsigned long events = 0;
 52
 53	spin_lock(&info->lock);
 54
 55	rtsr = readl_relaxed(info->rtsr);
 56	/* clear interrupt sources */
 57	writel_relaxed(0, info->rtsr);
 58	/* Fix for a nasty initialization problem the in SA11xx RTSR register.
 59	 * See also the comments in sa1100_rtc_probe(). */
 60	if (rtsr & (RTSR_ALE | RTSR_HZE)) {
 61		/* This is the original code, before there was the if test
 62		 * above. This code does not clear interrupts that were not
 63		 * enabled. */
 64		writel_relaxed((RTSR_AL | RTSR_HZ) & (rtsr >> 2), info->rtsr);
 65	} else {
 66		/* For some reason, it is possible to enter this routine
 67		 * without interruptions enabled, it has been tested with
 68		 * several units (Bug in SA11xx chip?).
 69		 *
 70		 * This situation leads to an infinite "loop" of interrupt
 71		 * routine calling and as a result the processor seems to
 72		 * lock on its first call to open(). */
 73		writel_relaxed(RTSR_AL | RTSR_HZ, info->rtsr);
 74	}
 75
 76	/* clear alarm interrupt if it has occurred */
 77	if (rtsr & RTSR_AL)
 78		rtsr &= ~RTSR_ALE;
 79	writel_relaxed(rtsr & (RTSR_ALE | RTSR_HZE), info->rtsr);
 80
 81	/* update irq data & counter */
 82	if (rtsr & RTSR_AL)
 83		events |= RTC_AF | RTC_IRQF;
 84	if (rtsr & RTSR_HZ)
 85		events |= RTC_UF | RTC_IRQF;
 86
 87	rtc_update_irq(rtc, 1, events);
 88
 89	spin_unlock(&info->lock);
 90
 91	return IRQ_HANDLED;
 92}
 93
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 94static int sa1100_rtc_alarm_irq_enable(struct device *dev, unsigned int enabled)
 95{
 96	u32 rtsr;
 97	struct sa1100_rtc *info = dev_get_drvdata(dev);
 98
 99	spin_lock_irq(&info->lock);
100	rtsr = readl_relaxed(info->rtsr);
101	if (enabled)
102		rtsr |= RTSR_ALE;
103	else
104		rtsr &= ~RTSR_ALE;
105	writel_relaxed(rtsr, info->rtsr);
106	spin_unlock_irq(&info->lock);
107	return 0;
108}
109
110static int sa1100_rtc_read_time(struct device *dev, struct rtc_time *tm)
111{
112	struct sa1100_rtc *info = dev_get_drvdata(dev);
113
114	rtc_time64_to_tm(readl_relaxed(info->rcnr), tm);
115	return 0;
116}
117
118static int sa1100_rtc_set_time(struct device *dev, struct rtc_time *tm)
119{
120	struct sa1100_rtc *info = dev_get_drvdata(dev);
121
122	writel_relaxed(rtc_tm_to_time64(tm), info->rcnr);
123
124	return 0;
 
 
 
125}
126
127static int sa1100_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alrm)
128{
129	u32	rtsr;
130	struct sa1100_rtc *info = dev_get_drvdata(dev);
131
132	rtsr = readl_relaxed(info->rtsr);
133	alrm->enabled = (rtsr & RTSR_ALE) ? 1 : 0;
134	alrm->pending = (rtsr & RTSR_AL) ? 1 : 0;
135	return 0;
136}
137
138static int sa1100_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm)
139{
140	struct sa1100_rtc *info = dev_get_drvdata(dev);
 
 
141
142	spin_lock_irq(&info->lock);
143	writel_relaxed(readl_relaxed(info->rtsr) &
144		(RTSR_HZE | RTSR_ALE | RTSR_AL), info->rtsr);
145	writel_relaxed(rtc_tm_to_time64(&alrm->time), info->rtar);
 
 
146	if (alrm->enabled)
147		writel_relaxed(readl_relaxed(info->rtsr) | RTSR_ALE, info->rtsr);
148	else
149		writel_relaxed(readl_relaxed(info->rtsr) & ~RTSR_ALE, info->rtsr);
 
150	spin_unlock_irq(&info->lock);
151
152	return 0;
153}
154
155static int sa1100_rtc_proc(struct device *dev, struct seq_file *seq)
156{
157	struct sa1100_rtc *info = dev_get_drvdata(dev);
158
159	seq_printf(seq, "trim/divider\t\t: 0x%08x\n", readl_relaxed(info->rttr));
160	seq_printf(seq, "RTSR\t\t\t: 0x%08x\n", readl_relaxed(info->rtsr));
161
162	return 0;
163}
164
165static const struct rtc_class_ops sa1100_rtc_ops = {
 
 
166	.read_time = sa1100_rtc_read_time,
167	.set_time = sa1100_rtc_set_time,
168	.read_alarm = sa1100_rtc_read_alarm,
169	.set_alarm = sa1100_rtc_set_alarm,
170	.proc = sa1100_rtc_proc,
171	.alarm_irq_enable = sa1100_rtc_alarm_irq_enable,
172};
173
174int sa1100_rtc_init(struct platform_device *pdev, struct sa1100_rtc *info)
175{
176	int ret;
 
 
177
178	spin_lock_init(&info->lock);
 
 
 
179
180	info->clk = devm_clk_get(&pdev->dev, NULL);
 
 
 
181	if (IS_ERR(info->clk)) {
182		dev_err(&pdev->dev, "failed to find rtc clock source\n");
183		return PTR_ERR(info->clk);
 
184	}
 
 
 
 
185
186	ret = clk_prepare_enable(info->clk);
187	if (ret)
188		return ret;
189	/*
190	 * According to the manual we should be able to let RTTR be zero
191	 * and then a default diviser for a 32.768KHz clock is used.
192	 * Apparently this doesn't work, at least for my SA1110 rev 5.
193	 * If the clock divider is uninitialized then reset it to the
194	 * default value to get the 1Hz clock.
195	 */
196	if (readl_relaxed(info->rttr) == 0) {
197		writel_relaxed(RTC_DEF_DIVIDER + (RTC_DEF_TRIM << 16), info->rttr);
198		dev_warn(&pdev->dev, "warning: "
199			"initializing default clock divider/trim value\n");
200		/* The current RTC value probably doesn't make sense either */
201		writel_relaxed(0, info->rcnr);
202	}
203
204	info->rtc->ops = &sa1100_rtc_ops;
205	info->rtc->max_user_freq = RTC_FREQ;
206	info->rtc->range_max = U32_MAX;
207
208	ret = devm_rtc_register_device(info->rtc);
209	if (ret) {
210		clk_disable_unprepare(info->clk);
211		return ret;
 
 
212	}
 
213
214	/* Fix for a nasty initialization problem the in SA11xx RTSR register.
215	 * See also the comments in sa1100_rtc_interrupt().
216	 *
217	 * Sometimes bit 1 of the RTSR (RTSR_HZ) will wake up 1, which means an
218	 * interrupt pending, even though interrupts were never enabled.
219	 * In this case, this bit it must be reset before enabling
220	 * interruptions to avoid a nonexistent interrupt to occur.
221	 *
222	 * In principle, the same problem would apply to bit 0, although it has
223	 * never been observed to happen.
224	 *
225	 * This issue is addressed both here and in sa1100_rtc_interrupt().
226	 * If the issue is not addressed here, in the times when the processor
227	 * wakes up with the bit set there will be one spurious interrupt.
228	 *
229	 * The issue is also dealt with in sa1100_rtc_interrupt() to be on the
230	 * safe side, once the condition that lead to this strange
231	 * initialization is unknown and could in principle happen during
232	 * normal processing.
233	 *
234	 * Notice that clearing bit 1 and 0 is accomplished by writting ONES to
235	 * the corresponding bits in RTSR. */
236	writel_relaxed(RTSR_AL | RTSR_HZ, info->rtsr);
237
238	return 0;
239}
240EXPORT_SYMBOL_GPL(sa1100_rtc_init);
241
242static int sa1100_rtc_probe(struct platform_device *pdev)
243{
244	struct sa1100_rtc *info;
245	void __iomem *base;
246	int irq_1hz, irq_alarm;
247	int ret;
248
249	irq_1hz = platform_get_irq_byname(pdev, "rtc 1Hz");
250	irq_alarm = platform_get_irq_byname(pdev, "rtc alarm");
251	if (irq_1hz < 0 || irq_alarm < 0)
252		return -ENODEV;
253
254	info = devm_kzalloc(&pdev->dev, sizeof(struct sa1100_rtc), GFP_KERNEL);
255	if (!info)
256		return -ENOMEM;
257	info->irq_1hz = irq_1hz;
258	info->irq_alarm = irq_alarm;
259
260	info->rtc = devm_rtc_allocate_device(&pdev->dev);
261	if (IS_ERR(info->rtc))
262		return PTR_ERR(info->rtc);
263
264	ret = devm_request_irq(&pdev->dev, irq_1hz, sa1100_rtc_interrupt, 0,
265			       "rtc 1Hz", &pdev->dev);
266	if (ret) {
267		dev_err(&pdev->dev, "IRQ %d already in use.\n", irq_1hz);
268		return ret;
269	}
270	ret = devm_request_irq(&pdev->dev, irq_alarm, sa1100_rtc_interrupt, 0,
271			       "rtc Alrm", &pdev->dev);
272	if (ret) {
273		dev_err(&pdev->dev, "IRQ %d already in use.\n", irq_alarm);
274		return ret;
275	}
276
277	base = devm_platform_ioremap_resource(pdev, 0);
278	if (IS_ERR(base))
279		return PTR_ERR(base);
280
281	if (IS_ENABLED(CONFIG_ARCH_SA1100) ||
282	    of_device_is_compatible(pdev->dev.of_node, "mrvl,sa1100-rtc")) {
283		info->rcnr = base + 0x04;
284		info->rtsr = base + 0x10;
285		info->rtar = base + 0x00;
286		info->rttr = base + 0x08;
287	} else {
288		info->rcnr = base + 0x0;
289		info->rtsr = base + 0x8;
290		info->rtar = base + 0x4;
291		info->rttr = base + 0xc;
292	}
293
294	platform_set_drvdata(pdev, info);
295	device_init_wakeup(&pdev->dev, 1);
296
297	return sa1100_rtc_init(pdev, info);
298}
299
300static int sa1100_rtc_remove(struct platform_device *pdev)
301{
302	struct sa1100_rtc *info = platform_get_drvdata(pdev);
303
304	if (info) {
305		spin_lock_irq(&info->lock);
306		writel_relaxed(0, info->rtsr);
307		spin_unlock_irq(&info->lock);
308		clk_disable_unprepare(info->clk);
309	}
310
311	return 0;
312}
313
314#ifdef CONFIG_PM_SLEEP
315static int sa1100_rtc_suspend(struct device *dev)
316{
317	struct sa1100_rtc *info = dev_get_drvdata(dev);
318	if (device_may_wakeup(dev))
319		enable_irq_wake(info->irq_alarm);
320	return 0;
321}
322
323static int sa1100_rtc_resume(struct device *dev)
324{
325	struct sa1100_rtc *info = dev_get_drvdata(dev);
326	if (device_may_wakeup(dev))
327		disable_irq_wake(info->irq_alarm);
328	return 0;
329}
330#endif
331
332static SIMPLE_DEV_PM_OPS(sa1100_rtc_pm_ops, sa1100_rtc_suspend,
333			sa1100_rtc_resume);
 
 
 
334
335#ifdef CONFIG_OF
336static const struct of_device_id sa1100_rtc_dt_ids[] = {
337	{ .compatible = "mrvl,sa1100-rtc", },
338	{ .compatible = "mrvl,mmp-rtc", },
339	{}
340};
341MODULE_DEVICE_TABLE(of, sa1100_rtc_dt_ids);
342#endif
343
344static struct platform_driver sa1100_rtc_driver = {
345	.probe		= sa1100_rtc_probe,
346	.remove		= sa1100_rtc_remove,
347	.driver		= {
348		.name	= "sa1100-rtc",
 
349		.pm	= &sa1100_rtc_pm_ops,
350		.of_match_table = of_match_ptr(sa1100_rtc_dt_ids),
 
351	},
352};
353
354module_platform_driver(sa1100_rtc_driver);
355
356MODULE_AUTHOR("Richard Purdie <rpurdie@rpsys.net>");
357MODULE_DESCRIPTION("SA11x0/PXA2xx Realtime Clock Driver (RTC)");
358MODULE_LICENSE("GPL");
359MODULE_ALIAS("platform:sa1100-rtc");
v3.5.6
 
  1/*
  2 * Real Time Clock interface for StrongARM SA1x00 and XScale PXA2xx
  3 *
  4 * Copyright (c) 2000 Nils Faerber
  5 *
  6 * Based on rtc.c by Paul Gortmaker
  7 *
  8 * Original Driver by Nils Faerber <nils@kernelconcepts.de>
  9 *
 10 * Modifications from:
 11 *   CIH <cih@coventive.com>
 12 *   Nicolas Pitre <nico@fluxnic.net>
 13 *   Andrew Christian <andrew.christian@hp.com>
 14 *
 15 * Converted to the RTC subsystem and Driver Model
 16 *   by Richard Purdie <rpurdie@rpsys.net>
 17 *
 18 * This program is free software; you can redistribute it and/or
 19 * modify it under the terms of the GNU General Public License
 20 * as published by the Free Software Foundation; either version
 21 * 2 of the License, or (at your option) any later version.
 22 */
 23
 24#include <linux/platform_device.h>
 25#include <linux/module.h>
 26#include <linux/clk.h>
 27#include <linux/rtc.h>
 28#include <linux/init.h>
 29#include <linux/fs.h>
 30#include <linux/interrupt.h>
 31#include <linux/slab.h>
 32#include <linux/string.h>
 33#include <linux/of.h>
 34#include <linux/pm.h>
 35#include <linux/bitops.h>
 36#include <linux/io.h>
 37
 38#include <mach/hardware.h>
 39#include <mach/irqs.h>
 
 
 40
 41#if defined(CONFIG_ARCH_PXA) || defined(CONFIG_ARCH_MMP)
 42#include <mach/regs-rtc.h>
 43#endif
 44
 45#define RTC_DEF_DIVIDER		(32768 - 1)
 46#define RTC_DEF_TRIM		0
 47#define RTC_FREQ		1024
 48
 49struct sa1100_rtc {
 50	spinlock_t		lock;
 51	int			irq_1hz;
 52	int			irq_alarm;
 53	struct rtc_device	*rtc;
 54	struct clk		*clk;
 55};
 56
 57static irqreturn_t sa1100_rtc_interrupt(int irq, void *dev_id)
 58{
 59	struct sa1100_rtc *info = dev_get_drvdata(dev_id);
 60	struct rtc_device *rtc = info->rtc;
 61	unsigned int rtsr;
 62	unsigned long events = 0;
 63
 64	spin_lock(&info->lock);
 65
 66	rtsr = RTSR;
 67	/* clear interrupt sources */
 68	RTSR = 0;
 69	/* Fix for a nasty initialization problem the in SA11xx RTSR register.
 70	 * See also the comments in sa1100_rtc_probe(). */
 71	if (rtsr & (RTSR_ALE | RTSR_HZE)) {
 72		/* This is the original code, before there was the if test
 73		 * above. This code does not clear interrupts that were not
 74		 * enabled. */
 75		RTSR = (RTSR_AL | RTSR_HZ) & (rtsr >> 2);
 76	} else {
 77		/* For some reason, it is possible to enter this routine
 78		 * without interruptions enabled, it has been tested with
 79		 * several units (Bug in SA11xx chip?).
 80		 *
 81		 * This situation leads to an infinite "loop" of interrupt
 82		 * routine calling and as a result the processor seems to
 83		 * lock on its first call to open(). */
 84		RTSR = RTSR_AL | RTSR_HZ;
 85	}
 86
 87	/* clear alarm interrupt if it has occurred */
 88	if (rtsr & RTSR_AL)
 89		rtsr &= ~RTSR_ALE;
 90	RTSR = rtsr & (RTSR_ALE | RTSR_HZE);
 91
 92	/* update irq data & counter */
 93	if (rtsr & RTSR_AL)
 94		events |= RTC_AF | RTC_IRQF;
 95	if (rtsr & RTSR_HZ)
 96		events |= RTC_UF | RTC_IRQF;
 97
 98	rtc_update_irq(rtc, 1, events);
 99
100	spin_unlock(&info->lock);
101
102	return IRQ_HANDLED;
103}
104
105static int sa1100_rtc_open(struct device *dev)
106{
107	struct sa1100_rtc *info = dev_get_drvdata(dev);
108	struct rtc_device *rtc = info->rtc;
109	int ret;
110
111	ret = clk_prepare_enable(info->clk);
112	if (ret)
113		goto fail_clk;
114	ret = request_irq(info->irq_1hz, sa1100_rtc_interrupt, 0, "rtc 1Hz", dev);
115	if (ret) {
116		dev_err(dev, "IRQ %d already in use.\n", info->irq_1hz);
117		goto fail_ui;
118	}
119	ret = request_irq(info->irq_alarm, sa1100_rtc_interrupt, 0, "rtc Alrm", dev);
120	if (ret) {
121		dev_err(dev, "IRQ %d already in use.\n", info->irq_alarm);
122		goto fail_ai;
123	}
124	rtc->max_user_freq = RTC_FREQ;
125	rtc_irq_set_freq(rtc, NULL, RTC_FREQ);
126
127	return 0;
128
129 fail_ai:
130	free_irq(info->irq_1hz, dev);
131 fail_ui:
132	clk_disable_unprepare(info->clk);
133 fail_clk:
134	return ret;
135}
136
137static void sa1100_rtc_release(struct device *dev)
138{
139	struct sa1100_rtc *info = dev_get_drvdata(dev);
140
141	spin_lock_irq(&info->lock);
142	RTSR = 0;
143	spin_unlock_irq(&info->lock);
144
145	free_irq(info->irq_alarm, dev);
146	free_irq(info->irq_1hz, dev);
147	clk_disable_unprepare(info->clk);
148}
149
150static int sa1100_rtc_alarm_irq_enable(struct device *dev, unsigned int enabled)
151{
 
152	struct sa1100_rtc *info = dev_get_drvdata(dev);
153
154	spin_lock_irq(&info->lock);
 
155	if (enabled)
156		RTSR |= RTSR_ALE;
157	else
158		RTSR &= ~RTSR_ALE;
 
159	spin_unlock_irq(&info->lock);
160	return 0;
161}
162
163static int sa1100_rtc_read_time(struct device *dev, struct rtc_time *tm)
164{
165	rtc_time_to_tm(RCNR, tm);
 
 
166	return 0;
167}
168
169static int sa1100_rtc_set_time(struct device *dev, struct rtc_time *tm)
170{
171	unsigned long time;
172	int ret;
 
173
174	ret = rtc_tm_to_time(tm, &time);
175	if (ret == 0)
176		RCNR = time;
177	return ret;
178}
179
180static int sa1100_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alrm)
181{
182	u32	rtsr;
 
183
184	rtsr = RTSR;
185	alrm->enabled = (rtsr & RTSR_ALE) ? 1 : 0;
186	alrm->pending = (rtsr & RTSR_AL) ? 1 : 0;
187	return 0;
188}
189
190static int sa1100_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm)
191{
192	struct sa1100_rtc *info = dev_get_drvdata(dev);
193	unsigned long time;
194	int ret;
195
196	spin_lock_irq(&info->lock);
197	ret = rtc_tm_to_time(&alrm->time, &time);
198	if (ret != 0)
199		goto out;
200	RTSR = RTSR & (RTSR_HZE|RTSR_ALE|RTSR_AL);
201	RTAR = time;
202	if (alrm->enabled)
203		RTSR |= RTSR_ALE;
204	else
205		RTSR &= ~RTSR_ALE;
206out:
207	spin_unlock_irq(&info->lock);
208
209	return ret;
210}
211
212static int sa1100_rtc_proc(struct device *dev, struct seq_file *seq)
213{
214	seq_printf(seq, "trim/divider\t\t: 0x%08x\n", (u32) RTTR);
215	seq_printf(seq, "RTSR\t\t\t: 0x%08x\n", (u32)RTSR);
 
 
216
217	return 0;
218}
219
220static const struct rtc_class_ops sa1100_rtc_ops = {
221	.open = sa1100_rtc_open,
222	.release = sa1100_rtc_release,
223	.read_time = sa1100_rtc_read_time,
224	.set_time = sa1100_rtc_set_time,
225	.read_alarm = sa1100_rtc_read_alarm,
226	.set_alarm = sa1100_rtc_set_alarm,
227	.proc = sa1100_rtc_proc,
228	.alarm_irq_enable = sa1100_rtc_alarm_irq_enable,
229};
230
231static int sa1100_rtc_probe(struct platform_device *pdev)
232{
233	struct rtc_device *rtc;
234	struct sa1100_rtc *info;
235	int irq_1hz, irq_alarm, ret = 0;
236
237	irq_1hz = platform_get_irq_byname(pdev, "rtc 1Hz");
238	irq_alarm = platform_get_irq_byname(pdev, "rtc alarm");
239	if (irq_1hz < 0 || irq_alarm < 0)
240		return -ENODEV;
241
242	info = kzalloc(sizeof(struct sa1100_rtc), GFP_KERNEL);
243	if (!info)
244		return -ENOMEM;
245	info->clk = clk_get(&pdev->dev, NULL);
246	if (IS_ERR(info->clk)) {
247		dev_err(&pdev->dev, "failed to find rtc clock source\n");
248		ret = PTR_ERR(info->clk);
249		goto err_clk;
250	}
251	info->irq_1hz = irq_1hz;
252	info->irq_alarm = irq_alarm;
253	spin_lock_init(&info->lock);
254	platform_set_drvdata(pdev, info);
255
 
 
 
256	/*
257	 * According to the manual we should be able to let RTTR be zero
258	 * and then a default diviser for a 32.768KHz clock is used.
259	 * Apparently this doesn't work, at least for my SA1110 rev 5.
260	 * If the clock divider is uninitialized then reset it to the
261	 * default value to get the 1Hz clock.
262	 */
263	if (RTTR == 0) {
264		RTTR = RTC_DEF_DIVIDER + (RTC_DEF_TRIM << 16);
265		dev_warn(&pdev->dev, "warning: "
266			"initializing default clock divider/trim value\n");
267		/* The current RTC value probably doesn't make sense either */
268		RCNR = 0;
269	}
270
271	device_init_wakeup(&pdev->dev, 1);
 
 
272
273	rtc = rtc_device_register(pdev->name, &pdev->dev, &sa1100_rtc_ops,
274		THIS_MODULE);
275
276	if (IS_ERR(rtc)) {
277		ret = PTR_ERR(rtc);
278		goto err_dev;
279	}
280	info->rtc = rtc;
281
282	/* Fix for a nasty initialization problem the in SA11xx RTSR register.
283	 * See also the comments in sa1100_rtc_interrupt().
284	 *
285	 * Sometimes bit 1 of the RTSR (RTSR_HZ) will wake up 1, which means an
286	 * interrupt pending, even though interrupts were never enabled.
287	 * In this case, this bit it must be reset before enabling
288	 * interruptions to avoid a nonexistent interrupt to occur.
289	 *
290	 * In principle, the same problem would apply to bit 0, although it has
291	 * never been observed to happen.
292	 *
293	 * This issue is addressed both here and in sa1100_rtc_interrupt().
294	 * If the issue is not addressed here, in the times when the processor
295	 * wakes up with the bit set there will be one spurious interrupt.
296	 *
297	 * The issue is also dealt with in sa1100_rtc_interrupt() to be on the
298	 * safe side, once the condition that lead to this strange
299	 * initialization is unknown and could in principle happen during
300	 * normal processing.
301	 *
302	 * Notice that clearing bit 1 and 0 is accomplished by writting ONES to
303	 * the corresponding bits in RTSR. */
304	RTSR = RTSR_AL | RTSR_HZ;
305
306	return 0;
307err_dev:
308	platform_set_drvdata(pdev, NULL);
309	clk_put(info->clk);
310err_clk:
311	kfree(info);
312	return ret;
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
313}
314
315static int sa1100_rtc_remove(struct platform_device *pdev)
316{
317	struct sa1100_rtc *info = platform_get_drvdata(pdev);
318
319	if (info) {
320		rtc_device_unregister(info->rtc);
321		clk_put(info->clk);
322		platform_set_drvdata(pdev, NULL);
323		kfree(info);
324	}
325
326	return 0;
327}
328
329#ifdef CONFIG_PM
330static int sa1100_rtc_suspend(struct device *dev)
331{
332	struct sa1100_rtc *info = dev_get_drvdata(dev);
333	if (device_may_wakeup(dev))
334		enable_irq_wake(info->irq_alarm);
335	return 0;
336}
337
338static int sa1100_rtc_resume(struct device *dev)
339{
340	struct sa1100_rtc *info = dev_get_drvdata(dev);
341	if (device_may_wakeup(dev))
342		disable_irq_wake(info->irq_alarm);
343	return 0;
344}
 
345
346static const struct dev_pm_ops sa1100_rtc_pm_ops = {
347	.suspend	= sa1100_rtc_suspend,
348	.resume		= sa1100_rtc_resume,
349};
350#endif
351
352static struct of_device_id sa1100_rtc_dt_ids[] = {
 
353	{ .compatible = "mrvl,sa1100-rtc", },
354	{ .compatible = "mrvl,mmp-rtc", },
355	{}
356};
357MODULE_DEVICE_TABLE(of, sa1100_rtc_dt_ids);
 
358
359static struct platform_driver sa1100_rtc_driver = {
360	.probe		= sa1100_rtc_probe,
361	.remove		= sa1100_rtc_remove,
362	.driver		= {
363		.name	= "sa1100-rtc",
364#ifdef CONFIG_PM
365		.pm	= &sa1100_rtc_pm_ops,
366#endif
367		.of_match_table = sa1100_rtc_dt_ids,
368	},
369};
370
371module_platform_driver(sa1100_rtc_driver);
372
373MODULE_AUTHOR("Richard Purdie <rpurdie@rpsys.net>");
374MODULE_DESCRIPTION("SA11x0/PXA2xx Realtime Clock Driver (RTC)");
375MODULE_LICENSE("GPL");
376MODULE_ALIAS("platform:sa1100-rtc");