2 * Copyright (C) 2009, Lars-Peter Clausen <lars@metafoo.de>
3 * JZ4720/JZ4740 SoC RTC driver
5 * This program is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License as published by the
7 * Free Software Foundation; either version 2 of the License, or (at your
8 * option) any later version.
10 * You should have received a copy of the GNU General Public License along
11 * with this program; if not, write to the Free Software Foundation, Inc.,
12 * 675 Mass Ave, Cambridge, MA 02139, USA.
16 #include <linux/kernel.h>
17 #include <linux/module.h>
18 #include <linux/platform_device.h>
19 #include <linux/spinlock.h>
20 #include <linux/rtc.h>
22 #define JZ_REG_RTC_CTRL 0x00
23 #define JZ_REG_RTC_SEC 0x04
24 #define JZ_REG_RTC_SEC_ALARM 0x08
25 #define JZ_REG_REGULATOR 0x0C
27 #define JZ_RTC_CTRL_WRDY BIT(7)
28 #define JZ_RTC_CTRL_1HZ BIT(6)
29 #define JZ_RTC_CTRL_1HZ_IRQ BIT(5)
30 #define JZ_RTC_CTRL_AF BIT(4)
31 #define JZ_RTC_CTRL_AF_IRQ BIT(3)
32 #define JZ_RTC_CTRL_AE BIT(2)
33 #define JZ_RTC_CTRL_ENABLE BIT(0)
39 struct rtc_device *rtc;
46 static inline uint32_t jz4740_rtc_reg_read(struct jz4740_rtc *rtc, size_t reg)
48 return readl(rtc->base + reg);
51 static inline void jz4740_rtc_wait_write_ready(struct jz4740_rtc *rtc)
55 ctrl = jz4740_rtc_reg_read(rtc, JZ_REG_RTC_CTRL);
56 } while (!(ctrl & JZ_RTC_CTRL_WRDY));
60 static inline void jz4740_rtc_reg_write(struct jz4740_rtc *rtc, size_t reg,
63 jz4740_rtc_wait_write_ready(rtc);
64 writel(val, rtc->base + reg);
67 static void jz4740_rtc_ctrl_set_bits(struct jz4740_rtc *rtc, uint32_t mask,
73 spin_lock_irqsave(&rtc->lock, flags);
75 ctrl = jz4740_rtc_reg_read(rtc, JZ_REG_RTC_CTRL);
77 /* Don't clear interrupt flags by accident */
78 ctrl |= JZ_RTC_CTRL_1HZ | JZ_RTC_CTRL_AF;
83 jz4740_rtc_reg_write(rtc, JZ_REG_RTC_CTRL, ctrl);
85 spin_unlock_irqrestore(&rtc->lock, flags);
88 static inline struct jz4740_rtc *dev_to_rtc(struct device *dev)
90 return dev_get_drvdata(dev);
93 static int jz4740_rtc_read_time(struct device *dev, struct rtc_time *time)
95 struct jz4740_rtc *rtc = dev_to_rtc(dev);
98 secs = jz4740_rtc_reg_read(rtc, JZ_REG_RTC_SEC);
99 secs2 = jz4740_rtc_reg_read(rtc, JZ_REG_RTC_SEC);
101 while (secs != secs2) {
103 secs2 = jz4740_rtc_reg_read(rtc, JZ_REG_RTC_SEC);
106 rtc_time_to_tm(secs, time);
108 return rtc_valid_tm(time);
111 static int jz4740_rtc_set_mmss(struct device *dev, unsigned long secs)
113 struct jz4740_rtc *rtc = dev_to_rtc(dev);
115 if ((uint32_t)secs != secs)
118 jz4740_rtc_reg_write(rtc, JZ_REG_RTC_SEC, secs);
123 static int jz4740_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alrm)
125 struct jz4740_rtc *rtc = dev_to_rtc(dev);
126 uint32_t secs, secs2;
129 secs = jz4740_rtc_reg_read(rtc, JZ_REG_RTC_SEC_ALARM);
130 secs2 = jz4740_rtc_reg_read(rtc, JZ_REG_RTC_SEC_ALARM);
132 while (secs != secs2){
134 secs2 = jz4740_rtc_reg_read(rtc, JZ_REG_RTC_SEC_ALARM);
137 ctrl = jz4740_rtc_reg_read(rtc, JZ_REG_RTC_CTRL);
139 alrm->enabled = !!(ctrl & JZ_RTC_CTRL_AE);
140 alrm->pending = !!(ctrl & JZ_RTC_CTRL_AF);
142 rtc_time_to_tm(secs, &alrm->time);
144 return rtc_valid_tm(&alrm->time);
147 static int jz4740_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm)
149 struct jz4740_rtc *rtc = dev_to_rtc(dev);
152 rtc_tm_to_time(&alrm->time, &secs);
154 if ((uint32_t)secs != secs)
157 jz4740_rtc_reg_write(rtc, JZ_REG_RTC_SEC_ALARM, (uint32_t)secs);
158 jz4740_rtc_ctrl_set_bits(rtc, JZ_RTC_CTRL_AE,
159 alrm->enabled ? JZ_RTC_CTRL_AE : 0);
164 static int jz4740_rtc_update_irq_enable(struct device *dev, unsigned int enabled)
166 struct jz4740_rtc *rtc = dev_to_rtc(dev);
167 jz4740_rtc_ctrl_set_bits(rtc, JZ_RTC_CTRL_1HZ_IRQ,
168 enabled ? JZ_RTC_CTRL_1HZ_IRQ : 0);
173 static int jz4740_rtc_alarm_irq_enable(struct device *dev, unsigned int enabled)
175 struct jz4740_rtc *rtc = dev_to_rtc(dev);
176 jz4740_rtc_ctrl_set_bits(rtc, JZ_RTC_CTRL_AF_IRQ,
177 enabled ? JZ_RTC_CTRL_AF_IRQ : 0);
181 static struct rtc_class_ops jz4740_rtc_ops = {
182 .read_time = jz4740_rtc_read_time,
183 .set_mmss = jz4740_rtc_set_mmss,
184 .read_alarm = jz4740_rtc_read_alarm,
185 .set_alarm = jz4740_rtc_set_alarm,
186 .update_irq_enable = jz4740_rtc_update_irq_enable,
187 .alarm_irq_enable = jz4740_rtc_alarm_irq_enable,
190 static irqreturn_t jz4740_rtc_irq(int irq, void *data)
192 struct jz4740_rtc *rtc = data;
194 unsigned long events = 0;
195 ctrl = jz4740_rtc_reg_read(rtc, JZ_REG_RTC_CTRL);
197 if (ctrl & JZ_RTC_CTRL_1HZ)
198 events |= (RTC_UF | RTC_IRQF);
200 if (ctrl & JZ_RTC_CTRL_AF)
201 events |= (RTC_AF | RTC_IRQF);
203 rtc_update_irq(rtc->rtc, 1, events);
205 jz4740_rtc_ctrl_set_bits(rtc, JZ_RTC_CTRL_1HZ | JZ_RTC_CTRL_AF, 0);
210 static int __devinit jz4740_rtc_probe(struct platform_device *pdev)
213 struct jz4740_rtc *rtc;
215 rtc = kmalloc(sizeof(*rtc), GFP_KERNEL);
217 rtc->irq = platform_get_irq(pdev, 0);
221 dev_err(&pdev->dev, "Failed to get platform irq\n");
225 rtc->mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
228 dev_err(&pdev->dev, "Failed to get platform mmio memory\n");
232 rtc->mem = request_mem_region(rtc->mem->start, resource_size(rtc->mem),
237 dev_err(&pdev->dev, "Failed to request mmio memory region\n");
241 rtc->base = ioremap_nocache(rtc->mem->start, resource_size(rtc->mem));
245 dev_err(&pdev->dev, "Failed to ioremap mmio memory\n");
246 goto err_release_mem_region;
249 platform_set_drvdata(pdev, rtc);
251 rtc->rtc = rtc_device_register(pdev->name, &pdev->dev, &jz4740_rtc_ops,
254 if (IS_ERR(rtc->rtc)) {
255 ret = PTR_ERR(rtc->rtc);
256 dev_err(&pdev->dev, "Failed to register rtc device: %d\n", ret);
260 ret = request_irq(rtc->irq, jz4740_rtc_irq, 0,
264 dev_err(&pdev->dev, "Failed to request rtc irq: %d\n", ret);
265 goto err_unregister_rtc;
267 printk("rtc-ctrl: %d\n", jz4740_rtc_reg_read(rtc, JZ_REG_RTC_CTRL));
272 rtc_device_unregister(rtc->rtc);
274 platform_set_drvdata(pdev, NULL);
276 err_release_mem_region:
277 release_mem_region(rtc->mem->start, resource_size(rtc->mem));
284 static int __devexit jz4740_rtc_remove(struct platform_device *pdev)
286 struct jz4740_rtc *rtc = platform_get_drvdata(pdev);
288 rtc_device_unregister(rtc->rtc);
291 release_mem_region(rtc->mem->start, resource_size(rtc->mem));
295 platform_set_drvdata(pdev, NULL);
300 struct platform_driver jz4740_rtc_driver = {
301 .probe = jz4740_rtc_probe,
302 .remove = __devexit_p(jz4740_rtc_remove),
304 .name = "jz4740-rtc",
305 .owner = THIS_MODULE,
309 static int __init jz4740_rtc_init(void)
311 return platform_driver_register(&jz4740_rtc_driver);
313 module_init(jz4740_rtc_init);
315 static void __exit jz4740_rtc_exit(void)
317 platform_driver_unregister(&jz4740_rtc_driver);
319 module_exit(jz4740_rtc_exit);
321 MODULE_AUTHOR("Lars-Peter Clausen <lars@metafoo.de>");
322 MODULE_LICENSE("GPL");
323 MODULE_DESCRIPTION("RTC driver for the JZ4720/JZ4740 SoC\n");
324 MODULE_ALIAS("platform:jz4740-rtc");
325 MODULE_ALIAS("platform:jz4720-rtc");