Linux Audio

Check our new training course

Loading...
v3.5.6
  1/*
  2 *  Copyright (C) 2009-2010, Lars-Peter Clausen <lars@metafoo.de>
  3 *  Copyright (C) 2010, Paul Cercueil <paul@crapouillou.net>
  4 *	 JZ4740 SoC RTC driver
  5 *
  6 *  This program is free software; you can redistribute it and/or modify it
  7 *  under  the terms of  the GNU General Public License as published by the
  8 *  Free Software Foundation;  either version 2 of the License, or (at your
  9 *  option) any later version.
 10 *
 11 *  You should have received a copy of the GNU General Public License along
 12 *  with this program; if not, write to the Free Software Foundation, Inc.,
 13 *  675 Mass Ave, Cambridge, MA 02139, USA.
 14 *
 15 */
 16
 17#include <linux/kernel.h>
 18#include <linux/module.h>
 19#include <linux/platform_device.h>
 20#include <linux/rtc.h>
 21#include <linux/slab.h>
 22#include <linux/spinlock.h>
 23
 24#define JZ_REG_RTC_CTRL		0x00
 25#define JZ_REG_RTC_SEC		0x04
 26#define JZ_REG_RTC_SEC_ALARM	0x08
 27#define JZ_REG_RTC_REGULATOR	0x0C
 28#define JZ_REG_RTC_HIBERNATE	0x20
 29#define JZ_REG_RTC_SCRATCHPAD	0x34
 30
 31#define JZ_RTC_CTRL_WRDY	BIT(7)
 32#define JZ_RTC_CTRL_1HZ		BIT(6)
 33#define JZ_RTC_CTRL_1HZ_IRQ	BIT(5)
 34#define JZ_RTC_CTRL_AF		BIT(4)
 35#define JZ_RTC_CTRL_AF_IRQ	BIT(3)
 36#define JZ_RTC_CTRL_AE		BIT(2)
 37#define JZ_RTC_CTRL_ENABLE	BIT(0)
 38
 39struct jz4740_rtc {
 40	struct resource *mem;
 41	void __iomem *base;
 42
 43	struct rtc_device *rtc;
 44
 45	unsigned int irq;
 46
 47	spinlock_t lock;
 48};
 49
 50static inline uint32_t jz4740_rtc_reg_read(struct jz4740_rtc *rtc, size_t reg)
 51{
 52	return readl(rtc->base + reg);
 53}
 54
 55static int jz4740_rtc_wait_write_ready(struct jz4740_rtc *rtc)
 56{
 57	uint32_t ctrl;
 58	int timeout = 1000;
 59
 60	do {
 61		ctrl = jz4740_rtc_reg_read(rtc, JZ_REG_RTC_CTRL);
 62	} while (!(ctrl & JZ_RTC_CTRL_WRDY) && --timeout);
 63
 64	return timeout ? 0 : -EIO;
 65}
 66
 67static inline int jz4740_rtc_reg_write(struct jz4740_rtc *rtc, size_t reg,
 68	uint32_t val)
 69{
 70	int ret;
 71	ret = jz4740_rtc_wait_write_ready(rtc);
 72	if (ret == 0)
 73		writel(val, rtc->base + reg);
 74
 75	return ret;
 76}
 77
 78static int jz4740_rtc_ctrl_set_bits(struct jz4740_rtc *rtc, uint32_t mask,
 79	bool set)
 80{
 81	int ret;
 82	unsigned long flags;
 83	uint32_t ctrl;
 84
 85	spin_lock_irqsave(&rtc->lock, flags);
 86
 87	ctrl = jz4740_rtc_reg_read(rtc, JZ_REG_RTC_CTRL);
 88
 89	/* Don't clear interrupt flags by accident */
 90	ctrl |= JZ_RTC_CTRL_1HZ | JZ_RTC_CTRL_AF;
 91
 92	if (set)
 93		ctrl |= mask;
 94	else
 95		ctrl &= ~mask;
 96
 97	ret = jz4740_rtc_reg_write(rtc, JZ_REG_RTC_CTRL, ctrl);
 98
 99	spin_unlock_irqrestore(&rtc->lock, flags);
100
101	return ret;
102}
103
104static int jz4740_rtc_read_time(struct device *dev, struct rtc_time *time)
105{
106	struct jz4740_rtc *rtc = dev_get_drvdata(dev);
107	uint32_t secs, secs2;
108	int timeout = 5;
109
110	/* If the seconds register is read while it is updated, it can contain a
111	 * bogus value. This can be avoided by making sure that two consecutive
112	 * reads have the same value.
113	 */
114	secs = jz4740_rtc_reg_read(rtc, JZ_REG_RTC_SEC);
115	secs2 = jz4740_rtc_reg_read(rtc, JZ_REG_RTC_SEC);
116
117	while (secs != secs2 && --timeout) {
118		secs = secs2;
119		secs2 = jz4740_rtc_reg_read(rtc, JZ_REG_RTC_SEC);
120	}
121
122	if (timeout == 0)
123		return -EIO;
124
125	rtc_time_to_tm(secs, time);
126
127	return rtc_valid_tm(time);
128}
129
130static int jz4740_rtc_set_mmss(struct device *dev, unsigned long secs)
131{
132	struct jz4740_rtc *rtc = dev_get_drvdata(dev);
133
134	return jz4740_rtc_reg_write(rtc, JZ_REG_RTC_SEC, secs);
135}
136
137static int jz4740_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alrm)
138{
139	struct jz4740_rtc *rtc = dev_get_drvdata(dev);
140	uint32_t secs;
141	uint32_t ctrl;
142
143	secs = jz4740_rtc_reg_read(rtc, JZ_REG_RTC_SEC_ALARM);
144
145	ctrl = jz4740_rtc_reg_read(rtc, JZ_REG_RTC_CTRL);
146
147	alrm->enabled = !!(ctrl & JZ_RTC_CTRL_AE);
148	alrm->pending = !!(ctrl & JZ_RTC_CTRL_AF);
149
150	rtc_time_to_tm(secs, &alrm->time);
151
152	return rtc_valid_tm(&alrm->time);
153}
154
155static int jz4740_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm)
156{
157	int ret;
158	struct jz4740_rtc *rtc = dev_get_drvdata(dev);
159	unsigned long secs;
160
161	rtc_tm_to_time(&alrm->time, &secs);
162
163	ret = jz4740_rtc_reg_write(rtc, JZ_REG_RTC_SEC_ALARM, secs);
164	if (!ret)
165		ret = jz4740_rtc_ctrl_set_bits(rtc,
166			JZ_RTC_CTRL_AE | JZ_RTC_CTRL_AF_IRQ, alrm->enabled);
167
168	return ret;
169}
170
171static int jz4740_rtc_alarm_irq_enable(struct device *dev, unsigned int enable)
172{
173	struct jz4740_rtc *rtc = dev_get_drvdata(dev);
174	return jz4740_rtc_ctrl_set_bits(rtc, JZ_RTC_CTRL_AF_IRQ, enable);
175}
176
177static struct rtc_class_ops jz4740_rtc_ops = {
178	.read_time	= jz4740_rtc_read_time,
179	.set_mmss	= jz4740_rtc_set_mmss,
180	.read_alarm	= jz4740_rtc_read_alarm,
181	.set_alarm	= jz4740_rtc_set_alarm,
182	.alarm_irq_enable = jz4740_rtc_alarm_irq_enable,
183};
184
185static irqreturn_t jz4740_rtc_irq(int irq, void *data)
186{
187	struct jz4740_rtc *rtc = data;
188	uint32_t ctrl;
189	unsigned long events = 0;
190
191	ctrl = jz4740_rtc_reg_read(rtc, JZ_REG_RTC_CTRL);
192
193	if (ctrl & JZ_RTC_CTRL_1HZ)
194		events |= (RTC_UF | RTC_IRQF);
195
196	if (ctrl & JZ_RTC_CTRL_AF)
197		events |= (RTC_AF | RTC_IRQF);
198
199	rtc_update_irq(rtc->rtc, 1, events);
200
201	jz4740_rtc_ctrl_set_bits(rtc, JZ_RTC_CTRL_1HZ | JZ_RTC_CTRL_AF, false);
202
203	return IRQ_HANDLED;
204}
205
206void jz4740_rtc_poweroff(struct device *dev)
207{
208	struct jz4740_rtc *rtc = dev_get_drvdata(dev);
209	jz4740_rtc_reg_write(rtc, JZ_REG_RTC_HIBERNATE, 1);
210}
211EXPORT_SYMBOL_GPL(jz4740_rtc_poweroff);
212
213static int __devinit jz4740_rtc_probe(struct platform_device *pdev)
214{
215	int ret;
216	struct jz4740_rtc *rtc;
217	uint32_t scratchpad;
218
219	rtc = kzalloc(sizeof(*rtc), GFP_KERNEL);
220	if (!rtc)
221		return -ENOMEM;
222
223	rtc->irq = platform_get_irq(pdev, 0);
224	if (rtc->irq < 0) {
225		ret = -ENOENT;
226		dev_err(&pdev->dev, "Failed to get platform irq\n");
227		goto err_free;
228	}
229
230	rtc->mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
231	if (!rtc->mem) {
232		ret = -ENOENT;
233		dev_err(&pdev->dev, "Failed to get platform mmio memory\n");
234		goto err_free;
235	}
236
237	rtc->mem = request_mem_region(rtc->mem->start, resource_size(rtc->mem),
238					pdev->name);
239	if (!rtc->mem) {
240		ret = -EBUSY;
241		dev_err(&pdev->dev, "Failed to request mmio memory region\n");
242		goto err_free;
243	}
244
245	rtc->base = ioremap_nocache(rtc->mem->start, resource_size(rtc->mem));
246	if (!rtc->base) {
247		ret = -EBUSY;
248		dev_err(&pdev->dev, "Failed to ioremap mmio memory\n");
249		goto err_release_mem_region;
250	}
251
252	spin_lock_init(&rtc->lock);
253
254	platform_set_drvdata(pdev, rtc);
255
256	device_init_wakeup(&pdev->dev, 1);
257
258	rtc->rtc = rtc_device_register(pdev->name, &pdev->dev, &jz4740_rtc_ops,
259					THIS_MODULE);
260	if (IS_ERR(rtc->rtc)) {
261		ret = PTR_ERR(rtc->rtc);
262		dev_err(&pdev->dev, "Failed to register rtc device: %d\n", ret);
263		goto err_iounmap;
264	}
265
266	ret = request_irq(rtc->irq, jz4740_rtc_irq, 0,
267				pdev->name, rtc);
268	if (ret) {
269		dev_err(&pdev->dev, "Failed to request rtc irq: %d\n", ret);
270		goto err_unregister_rtc;
271	}
272
273	scratchpad = jz4740_rtc_reg_read(rtc, JZ_REG_RTC_SCRATCHPAD);
274	if (scratchpad != 0x12345678) {
275		ret = jz4740_rtc_reg_write(rtc, JZ_REG_RTC_SCRATCHPAD, 0x12345678);
276		ret = jz4740_rtc_reg_write(rtc, JZ_REG_RTC_SEC, 0);
277		if (ret) {
278			dev_err(&pdev->dev, "Could not write write to RTC registers\n");
279			goto err_free_irq;
280		}
281	}
282
283	return 0;
284
285err_free_irq:
286	free_irq(rtc->irq, rtc);
287err_unregister_rtc:
288	rtc_device_unregister(rtc->rtc);
289err_iounmap:
290	platform_set_drvdata(pdev, NULL);
291	iounmap(rtc->base);
292err_release_mem_region:
293	release_mem_region(rtc->mem->start, resource_size(rtc->mem));
294err_free:
295	kfree(rtc);
296
297	return ret;
298}
299
300static int __devexit jz4740_rtc_remove(struct platform_device *pdev)
301{
302	struct jz4740_rtc *rtc = platform_get_drvdata(pdev);
303
304	free_irq(rtc->irq, rtc);
305
306	rtc_device_unregister(rtc->rtc);
307
308	iounmap(rtc->base);
309	release_mem_region(rtc->mem->start, resource_size(rtc->mem));
310
311	kfree(rtc);
312
313	platform_set_drvdata(pdev, NULL);
314
315	return 0;
316}
317
318
319#ifdef CONFIG_PM
320static int jz4740_rtc_suspend(struct device *dev)
321{
322	struct jz4740_rtc *rtc = dev_get_drvdata(dev);
323
324	if (device_may_wakeup(dev))
325		enable_irq_wake(rtc->irq);
326	return 0;
327}
328
329static int jz4740_rtc_resume(struct device *dev)
330{
331	struct jz4740_rtc *rtc = dev_get_drvdata(dev);
332
333	if (device_may_wakeup(dev))
334		disable_irq_wake(rtc->irq);
335	return 0;
336}
337
338static const struct dev_pm_ops jz4740_pm_ops = {
339	.suspend = jz4740_rtc_suspend,
340	.resume  = jz4740_rtc_resume,
341};
342#define JZ4740_RTC_PM_OPS (&jz4740_pm_ops)
343
344#else
345#define JZ4740_RTC_PM_OPS NULL
346#endif  /* CONFIG_PM */
347
348static struct platform_driver jz4740_rtc_driver = {
349	.probe	 = jz4740_rtc_probe,
350	.remove	 = __devexit_p(jz4740_rtc_remove),
351	.driver	 = {
352		.name  = "jz4740-rtc",
353		.owner = THIS_MODULE,
354		.pm    = JZ4740_RTC_PM_OPS,
355	},
356};
357
358module_platform_driver(jz4740_rtc_driver);
 
 
 
 
 
 
 
 
 
 
359
360MODULE_AUTHOR("Lars-Peter Clausen <lars@metafoo.de>");
361MODULE_LICENSE("GPL");
362MODULE_DESCRIPTION("RTC driver for the JZ4740 SoC\n");
363MODULE_ALIAS("platform:jz4740-rtc");
v3.1
  1/*
  2 *  Copyright (C) 2009-2010, Lars-Peter Clausen <lars@metafoo.de>
  3 *  Copyright (C) 2010, Paul Cercueil <paul@crapouillou.net>
  4 *	 JZ4740 SoC RTC driver
  5 *
  6 *  This program is free software; you can redistribute it and/or modify it
  7 *  under  the terms of  the GNU General Public License as published by the
  8 *  Free Software Foundation;  either version 2 of the License, or (at your
  9 *  option) any later version.
 10 *
 11 *  You should have received a copy of the GNU General Public License along
 12 *  with this program; if not, write to the Free Software Foundation, Inc.,
 13 *  675 Mass Ave, Cambridge, MA 02139, USA.
 14 *
 15 */
 16
 17#include <linux/kernel.h>
 18#include <linux/module.h>
 19#include <linux/platform_device.h>
 20#include <linux/rtc.h>
 21#include <linux/slab.h>
 22#include <linux/spinlock.h>
 23
 24#define JZ_REG_RTC_CTRL		0x00
 25#define JZ_REG_RTC_SEC		0x04
 26#define JZ_REG_RTC_SEC_ALARM	0x08
 27#define JZ_REG_RTC_REGULATOR	0x0C
 28#define JZ_REG_RTC_HIBERNATE	0x20
 29#define JZ_REG_RTC_SCRATCHPAD	0x34
 30
 31#define JZ_RTC_CTRL_WRDY	BIT(7)
 32#define JZ_RTC_CTRL_1HZ		BIT(6)
 33#define JZ_RTC_CTRL_1HZ_IRQ	BIT(5)
 34#define JZ_RTC_CTRL_AF		BIT(4)
 35#define JZ_RTC_CTRL_AF_IRQ	BIT(3)
 36#define JZ_RTC_CTRL_AE		BIT(2)
 37#define JZ_RTC_CTRL_ENABLE	BIT(0)
 38
 39struct jz4740_rtc {
 40	struct resource *mem;
 41	void __iomem *base;
 42
 43	struct rtc_device *rtc;
 44
 45	unsigned int irq;
 46
 47	spinlock_t lock;
 48};
 49
 50static inline uint32_t jz4740_rtc_reg_read(struct jz4740_rtc *rtc, size_t reg)
 51{
 52	return readl(rtc->base + reg);
 53}
 54
 55static int jz4740_rtc_wait_write_ready(struct jz4740_rtc *rtc)
 56{
 57	uint32_t ctrl;
 58	int timeout = 1000;
 59
 60	do {
 61		ctrl = jz4740_rtc_reg_read(rtc, JZ_REG_RTC_CTRL);
 62	} while (!(ctrl & JZ_RTC_CTRL_WRDY) && --timeout);
 63
 64	return timeout ? 0 : -EIO;
 65}
 66
 67static inline int jz4740_rtc_reg_write(struct jz4740_rtc *rtc, size_t reg,
 68	uint32_t val)
 69{
 70	int ret;
 71	ret = jz4740_rtc_wait_write_ready(rtc);
 72	if (ret == 0)
 73		writel(val, rtc->base + reg);
 74
 75	return ret;
 76}
 77
 78static int jz4740_rtc_ctrl_set_bits(struct jz4740_rtc *rtc, uint32_t mask,
 79	bool set)
 80{
 81	int ret;
 82	unsigned long flags;
 83	uint32_t ctrl;
 84
 85	spin_lock_irqsave(&rtc->lock, flags);
 86
 87	ctrl = jz4740_rtc_reg_read(rtc, JZ_REG_RTC_CTRL);
 88
 89	/* Don't clear interrupt flags by accident */
 90	ctrl |= JZ_RTC_CTRL_1HZ | JZ_RTC_CTRL_AF;
 91
 92	if (set)
 93		ctrl |= mask;
 94	else
 95		ctrl &= ~mask;
 96
 97	ret = jz4740_rtc_reg_write(rtc, JZ_REG_RTC_CTRL, ctrl);
 98
 99	spin_unlock_irqrestore(&rtc->lock, flags);
100
101	return ret;
102}
103
104static int jz4740_rtc_read_time(struct device *dev, struct rtc_time *time)
105{
106	struct jz4740_rtc *rtc = dev_get_drvdata(dev);
107	uint32_t secs, secs2;
108	int timeout = 5;
109
110	/* If the seconds register is read while it is updated, it can contain a
111	 * bogus value. This can be avoided by making sure that two consecutive
112	 * reads have the same value.
113	 */
114	secs = jz4740_rtc_reg_read(rtc, JZ_REG_RTC_SEC);
115	secs2 = jz4740_rtc_reg_read(rtc, JZ_REG_RTC_SEC);
116
117	while (secs != secs2 && --timeout) {
118		secs = secs2;
119		secs2 = jz4740_rtc_reg_read(rtc, JZ_REG_RTC_SEC);
120	}
121
122	if (timeout == 0)
123		return -EIO;
124
125	rtc_time_to_tm(secs, time);
126
127	return rtc_valid_tm(time);
128}
129
130static int jz4740_rtc_set_mmss(struct device *dev, unsigned long secs)
131{
132	struct jz4740_rtc *rtc = dev_get_drvdata(dev);
133
134	return jz4740_rtc_reg_write(rtc, JZ_REG_RTC_SEC, secs);
135}
136
137static int jz4740_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alrm)
138{
139	struct jz4740_rtc *rtc = dev_get_drvdata(dev);
140	uint32_t secs;
141	uint32_t ctrl;
142
143	secs = jz4740_rtc_reg_read(rtc, JZ_REG_RTC_SEC_ALARM);
144
145	ctrl = jz4740_rtc_reg_read(rtc, JZ_REG_RTC_CTRL);
146
147	alrm->enabled = !!(ctrl & JZ_RTC_CTRL_AE);
148	alrm->pending = !!(ctrl & JZ_RTC_CTRL_AF);
149
150	rtc_time_to_tm(secs, &alrm->time);
151
152	return rtc_valid_tm(&alrm->time);
153}
154
155static int jz4740_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm)
156{
157	int ret;
158	struct jz4740_rtc *rtc = dev_get_drvdata(dev);
159	unsigned long secs;
160
161	rtc_tm_to_time(&alrm->time, &secs);
162
163	ret = jz4740_rtc_reg_write(rtc, JZ_REG_RTC_SEC_ALARM, secs);
164	if (!ret)
165		ret = jz4740_rtc_ctrl_set_bits(rtc,
166			JZ_RTC_CTRL_AE | JZ_RTC_CTRL_AF_IRQ, alrm->enabled);
167
168	return ret;
169}
170
171static int jz4740_rtc_alarm_irq_enable(struct device *dev, unsigned int enable)
172{
173	struct jz4740_rtc *rtc = dev_get_drvdata(dev);
174	return jz4740_rtc_ctrl_set_bits(rtc, JZ_RTC_CTRL_AF_IRQ, enable);
175}
176
177static struct rtc_class_ops jz4740_rtc_ops = {
178	.read_time	= jz4740_rtc_read_time,
179	.set_mmss	= jz4740_rtc_set_mmss,
180	.read_alarm	= jz4740_rtc_read_alarm,
181	.set_alarm	= jz4740_rtc_set_alarm,
182	.alarm_irq_enable = jz4740_rtc_alarm_irq_enable,
183};
184
185static irqreturn_t jz4740_rtc_irq(int irq, void *data)
186{
187	struct jz4740_rtc *rtc = data;
188	uint32_t ctrl;
189	unsigned long events = 0;
190
191	ctrl = jz4740_rtc_reg_read(rtc, JZ_REG_RTC_CTRL);
192
193	if (ctrl & JZ_RTC_CTRL_1HZ)
194		events |= (RTC_UF | RTC_IRQF);
195
196	if (ctrl & JZ_RTC_CTRL_AF)
197		events |= (RTC_AF | RTC_IRQF);
198
199	rtc_update_irq(rtc->rtc, 1, events);
200
201	jz4740_rtc_ctrl_set_bits(rtc, JZ_RTC_CTRL_1HZ | JZ_RTC_CTRL_AF, false);
202
203	return IRQ_HANDLED;
204}
205
206void jz4740_rtc_poweroff(struct device *dev)
207{
208	struct jz4740_rtc *rtc = dev_get_drvdata(dev);
209	jz4740_rtc_reg_write(rtc, JZ_REG_RTC_HIBERNATE, 1);
210}
211EXPORT_SYMBOL_GPL(jz4740_rtc_poweroff);
212
213static int __devinit jz4740_rtc_probe(struct platform_device *pdev)
214{
215	int ret;
216	struct jz4740_rtc *rtc;
217	uint32_t scratchpad;
218
219	rtc = kzalloc(sizeof(*rtc), GFP_KERNEL);
220	if (!rtc)
221		return -ENOMEM;
222
223	rtc->irq = platform_get_irq(pdev, 0);
224	if (rtc->irq < 0) {
225		ret = -ENOENT;
226		dev_err(&pdev->dev, "Failed to get platform irq\n");
227		goto err_free;
228	}
229
230	rtc->mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
231	if (!rtc->mem) {
232		ret = -ENOENT;
233		dev_err(&pdev->dev, "Failed to get platform mmio memory\n");
234		goto err_free;
235	}
236
237	rtc->mem = request_mem_region(rtc->mem->start, resource_size(rtc->mem),
238					pdev->name);
239	if (!rtc->mem) {
240		ret = -EBUSY;
241		dev_err(&pdev->dev, "Failed to request mmio memory region\n");
242		goto err_free;
243	}
244
245	rtc->base = ioremap_nocache(rtc->mem->start, resource_size(rtc->mem));
246	if (!rtc->base) {
247		ret = -EBUSY;
248		dev_err(&pdev->dev, "Failed to ioremap mmio memory\n");
249		goto err_release_mem_region;
250	}
251
252	spin_lock_init(&rtc->lock);
253
254	platform_set_drvdata(pdev, rtc);
255
256	device_init_wakeup(&pdev->dev, 1);
257
258	rtc->rtc = rtc_device_register(pdev->name, &pdev->dev, &jz4740_rtc_ops,
259					THIS_MODULE);
260	if (IS_ERR(rtc->rtc)) {
261		ret = PTR_ERR(rtc->rtc);
262		dev_err(&pdev->dev, "Failed to register rtc device: %d\n", ret);
263		goto err_iounmap;
264	}
265
266	ret = request_irq(rtc->irq, jz4740_rtc_irq, 0,
267				pdev->name, rtc);
268	if (ret) {
269		dev_err(&pdev->dev, "Failed to request rtc irq: %d\n", ret);
270		goto err_unregister_rtc;
271	}
272
273	scratchpad = jz4740_rtc_reg_read(rtc, JZ_REG_RTC_SCRATCHPAD);
274	if (scratchpad != 0x12345678) {
275		ret = jz4740_rtc_reg_write(rtc, JZ_REG_RTC_SCRATCHPAD, 0x12345678);
276		ret = jz4740_rtc_reg_write(rtc, JZ_REG_RTC_SEC, 0);
277		if (ret) {
278			dev_err(&pdev->dev, "Could not write write to RTC registers\n");
279			goto err_free_irq;
280		}
281	}
282
283	return 0;
284
285err_free_irq:
286	free_irq(rtc->irq, rtc);
287err_unregister_rtc:
288	rtc_device_unregister(rtc->rtc);
289err_iounmap:
290	platform_set_drvdata(pdev, NULL);
291	iounmap(rtc->base);
292err_release_mem_region:
293	release_mem_region(rtc->mem->start, resource_size(rtc->mem));
294err_free:
295	kfree(rtc);
296
297	return ret;
298}
299
300static int __devexit jz4740_rtc_remove(struct platform_device *pdev)
301{
302	struct jz4740_rtc *rtc = platform_get_drvdata(pdev);
303
304	free_irq(rtc->irq, rtc);
305
306	rtc_device_unregister(rtc->rtc);
307
308	iounmap(rtc->base);
309	release_mem_region(rtc->mem->start, resource_size(rtc->mem));
310
311	kfree(rtc);
312
313	platform_set_drvdata(pdev, NULL);
314
315	return 0;
316}
317
318
319#ifdef CONFIG_PM
320static int jz4740_rtc_suspend(struct device *dev)
321{
322	struct jz4740_rtc *rtc = dev_get_drvdata(dev);
323
324	if (device_may_wakeup(dev))
325		enable_irq_wake(rtc->irq);
326	return 0;
327}
328
329static int jz4740_rtc_resume(struct device *dev)
330{
331	struct jz4740_rtc *rtc = dev_get_drvdata(dev);
332
333	if (device_may_wakeup(dev))
334		disable_irq_wake(rtc->irq);
335	return 0;
336}
337
338static const struct dev_pm_ops jz4740_pm_ops = {
339	.suspend = jz4740_rtc_suspend,
340	.resume  = jz4740_rtc_resume,
341};
342#define JZ4740_RTC_PM_OPS (&jz4740_pm_ops)
343
344#else
345#define JZ4740_RTC_PM_OPS NULL
346#endif  /* CONFIG_PM */
347
348struct platform_driver jz4740_rtc_driver = {
349	.probe	 = jz4740_rtc_probe,
350	.remove	 = __devexit_p(jz4740_rtc_remove),
351	.driver	 = {
352		.name  = "jz4740-rtc",
353		.owner = THIS_MODULE,
354		.pm    = JZ4740_RTC_PM_OPS,
355	},
356};
357
358static int __init jz4740_rtc_init(void)
359{
360	return platform_driver_register(&jz4740_rtc_driver);
361}
362module_init(jz4740_rtc_init);
363
364static void __exit jz4740_rtc_exit(void)
365{
366	platform_driver_unregister(&jz4740_rtc_driver);
367}
368module_exit(jz4740_rtc_exit);
369
370MODULE_AUTHOR("Lars-Peter Clausen <lars@metafoo.de>");
371MODULE_LICENSE("GPL");
372MODULE_DESCRIPTION("RTC driver for the JZ4740 SoC\n");
373MODULE_ALIAS("platform:jz4740-rtc");