Merge branch 'release' of git://git.kernel.org/pub/scm/linux/kernel/git/lenb/linux...
[linux-2.6.git] / drivers / rtc / rtc-at32ap700x.c
1 /*
2  * An RTC driver for the AVR32 AT32AP700x processor series.
3  *
4  * Copyright (C) 2007 Atmel Corporation
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 version 2 as published
8  * by the Free Software Foundation.
9  */
10
11 #include <linux/module.h>
12 #include <linux/kernel.h>
13 #include <linux/platform_device.h>
14 #include <linux/slab.h>
15 #include <linux/rtc.h>
16 #include <linux/io.h>
17
18 /*
19  * This is a bare-bones RTC. It runs during most system sleep states, but has
20  * no battery backup and gets reset during system restart.  It must be
21  * initialized from an external clock (network, I2C, etc) before it can be of
22  * much use.
23  *
24  * The alarm functionality is limited by the hardware, not supporting
25  * periodic interrupts.
26  */
27
28 #define RTC_CTRL                0x00
29 #define RTC_CTRL_EN                0
30 #define RTC_CTRL_PCLR              1
31 #define RTC_CTRL_TOPEN             2
32 #define RTC_CTRL_PSEL              8
33
34 #define RTC_VAL                 0x04
35
36 #define RTC_TOP                 0x08
37
38 #define RTC_IER                 0x10
39 #define RTC_IER_TOPI               0
40
41 #define RTC_IDR                 0x14
42 #define RTC_IDR_TOPI               0
43
44 #define RTC_IMR                 0x18
45 #define RTC_IMR_TOPI               0
46
47 #define RTC_ISR                 0x1c
48 #define RTC_ISR_TOPI               0
49
50 #define RTC_ICR                 0x20
51 #define RTC_ICR_TOPI               0
52
53 #define RTC_BIT(name)           (1 << RTC_##name)
54 #define RTC_BF(name, value)     ((value) << RTC_##name)
55
56 #define rtc_readl(dev, reg)                             \
57         __raw_readl((dev)->regs + RTC_##reg)
58 #define rtc_writel(dev, reg, value)                     \
59         __raw_writel((value), (dev)->regs + RTC_##reg)
60
61 struct rtc_at32ap700x {
62         struct rtc_device       *rtc;
63         void __iomem            *regs;
64         unsigned long           alarm_time;
65         unsigned long           irq;
66         /* Protect against concurrent register access. */
67         spinlock_t              lock;
68 };
69
70 static int at32_rtc_readtime(struct device *dev, struct rtc_time *tm)
71 {
72         struct rtc_at32ap700x *rtc = dev_get_drvdata(dev);
73         unsigned long now;
74
75         now = rtc_readl(rtc, VAL);
76         rtc_time_to_tm(now, tm);
77
78         return 0;
79 }
80
81 static int at32_rtc_settime(struct device *dev, struct rtc_time *tm)
82 {
83         struct rtc_at32ap700x *rtc = dev_get_drvdata(dev);
84         unsigned long now;
85         int ret;
86
87         ret = rtc_tm_to_time(tm, &now);
88         if (ret == 0)
89                 rtc_writel(rtc, VAL, now);
90
91         return ret;
92 }
93
94 static int at32_rtc_readalarm(struct device *dev, struct rtc_wkalrm *alrm)
95 {
96         struct rtc_at32ap700x *rtc = dev_get_drvdata(dev);
97
98         spin_lock_irq(&rtc->lock);
99         rtc_time_to_tm(rtc->alarm_time, &alrm->time);
100         alrm->enabled = rtc_readl(rtc, IMR) & RTC_BIT(IMR_TOPI) ? 1 : 0;
101         alrm->pending = rtc_readl(rtc, ISR) & RTC_BIT(ISR_TOPI) ? 1 : 0;
102         spin_unlock_irq(&rtc->lock);
103
104         return 0;
105 }
106
107 static int at32_rtc_setalarm(struct device *dev, struct rtc_wkalrm *alrm)
108 {
109         struct rtc_at32ap700x *rtc = dev_get_drvdata(dev);
110         unsigned long rtc_unix_time;
111         unsigned long alarm_unix_time;
112         int ret;
113
114         rtc_unix_time = rtc_readl(rtc, VAL);
115
116         ret = rtc_tm_to_time(&alrm->time, &alarm_unix_time);
117         if (ret)
118                 return ret;
119
120         if (alarm_unix_time < rtc_unix_time)
121                 return -EINVAL;
122
123         spin_lock_irq(&rtc->lock);
124         rtc->alarm_time = alarm_unix_time;
125         rtc_writel(rtc, TOP, rtc->alarm_time);
126         if (alrm->enabled)
127                 rtc_writel(rtc, CTRL, rtc_readl(rtc, CTRL)
128                                 | RTC_BIT(CTRL_TOPEN));
129         else
130                 rtc_writel(rtc, CTRL, rtc_readl(rtc, CTRL)
131                                 & ~RTC_BIT(CTRL_TOPEN));
132         spin_unlock_irq(&rtc->lock);
133
134         return ret;
135 }
136
137 static int at32_rtc_ioctl(struct device *dev, unsigned int cmd,
138                         unsigned long arg)
139 {
140         struct rtc_at32ap700x *rtc = dev_get_drvdata(dev);
141         int ret = 0;
142
143         spin_lock_irq(&rtc->lock);
144
145         switch (cmd) {
146         case RTC_AIE_ON:
147                 if (rtc_readl(rtc, VAL) > rtc->alarm_time) {
148                         ret = -EINVAL;
149                         break;
150                 }
151                 rtc_writel(rtc, CTRL, rtc_readl(rtc, CTRL)
152                                 | RTC_BIT(CTRL_TOPEN));
153                 rtc_writel(rtc, ICR, RTC_BIT(ICR_TOPI));
154                 rtc_writel(rtc, IER, RTC_BIT(IER_TOPI));
155                 break;
156         case RTC_AIE_OFF:
157                 rtc_writel(rtc, CTRL, rtc_readl(rtc, CTRL)
158                                 & ~RTC_BIT(CTRL_TOPEN));
159                 rtc_writel(rtc, IDR, RTC_BIT(IDR_TOPI));
160                 rtc_writel(rtc, ICR, RTC_BIT(ICR_TOPI));
161                 break;
162         default:
163                 ret = -ENOIOCTLCMD;
164                 break;
165         }
166
167         spin_unlock_irq(&rtc->lock);
168
169         return ret;
170 }
171
172 static irqreturn_t at32_rtc_interrupt(int irq, void *dev_id)
173 {
174         struct rtc_at32ap700x *rtc = (struct rtc_at32ap700x *)dev_id;
175         unsigned long isr = rtc_readl(rtc, ISR);
176         unsigned long events = 0;
177         int ret = IRQ_NONE;
178
179         spin_lock(&rtc->lock);
180
181         if (isr & RTC_BIT(ISR_TOPI)) {
182                 rtc_writel(rtc, ICR, RTC_BIT(ICR_TOPI));
183                 rtc_writel(rtc, IDR, RTC_BIT(IDR_TOPI));
184                 rtc_writel(rtc, CTRL, rtc_readl(rtc, CTRL)
185                                 & ~RTC_BIT(CTRL_TOPEN));
186                 rtc_writel(rtc, VAL, rtc->alarm_time);
187                 events = RTC_AF | RTC_IRQF;
188                 rtc_update_irq(rtc->rtc, 1, events);
189                 ret = IRQ_HANDLED;
190         }
191
192         spin_unlock(&rtc->lock);
193
194         return ret;
195 }
196
197 static struct rtc_class_ops at32_rtc_ops = {
198         .ioctl          = at32_rtc_ioctl,
199         .read_time      = at32_rtc_readtime,
200         .set_time       = at32_rtc_settime,
201         .read_alarm     = at32_rtc_readalarm,
202         .set_alarm      = at32_rtc_setalarm,
203 };
204
205 static int __init at32_rtc_probe(struct platform_device *pdev)
206 {
207         struct resource *regs;
208         struct rtc_at32ap700x *rtc;
209         int irq;
210         int ret;
211
212         rtc = kzalloc(sizeof(struct rtc_at32ap700x), GFP_KERNEL);
213         if (!rtc) {
214                 dev_dbg(&pdev->dev, "out of memory\n");
215                 return -ENOMEM;
216         }
217
218         regs = platform_get_resource(pdev, IORESOURCE_MEM, 0);
219         if (!regs) {
220                 dev_dbg(&pdev->dev, "no mmio resource defined\n");
221                 ret = -ENXIO;
222                 goto out;
223         }
224
225         irq = platform_get_irq(pdev, 0);
226         if (irq <= 0) {
227                 dev_dbg(&pdev->dev, "could not get irq\n");
228                 ret = -ENXIO;
229                 goto out;
230         }
231
232         rtc->irq = irq;
233         rtc->regs = ioremap(regs->start, regs->end - regs->start + 1);
234         if (!rtc->regs) {
235                 ret = -ENOMEM;
236                 dev_dbg(&pdev->dev, "could not map I/O memory\n");
237                 goto out;
238         }
239         spin_lock_init(&rtc->lock);
240
241         /*
242          * Maybe init RTC: count from zero at 1 Hz, disable wrap irq.
243          *
244          * Do not reset VAL register, as it can hold an old time
245          * from last JTAG reset.
246          */
247         if (!(rtc_readl(rtc, CTRL) & RTC_BIT(CTRL_EN))) {
248                 rtc_writel(rtc, CTRL, RTC_BIT(CTRL_PCLR));
249                 rtc_writel(rtc, IDR, RTC_BIT(IDR_TOPI));
250                 rtc_writel(rtc, CTRL, RTC_BF(CTRL_PSEL, 0xe)
251                                 | RTC_BIT(CTRL_EN));
252         }
253
254         ret = request_irq(irq, at32_rtc_interrupt, IRQF_SHARED, "rtc", rtc);
255         if (ret) {
256                 dev_dbg(&pdev->dev, "could not request irq %d\n", irq);
257                 goto out_iounmap;
258         }
259
260         platform_set_drvdata(pdev, rtc);
261
262         rtc->rtc = rtc_device_register(pdev->name, &pdev->dev,
263                                 &at32_rtc_ops, THIS_MODULE);
264         if (IS_ERR(rtc->rtc)) {
265                 dev_dbg(&pdev->dev, "could not register rtc device\n");
266                 ret = PTR_ERR(rtc->rtc);
267                 goto out_free_irq;
268         }
269
270         device_init_wakeup(&pdev->dev, 1);
271
272         dev_info(&pdev->dev, "Atmel RTC for AT32AP700x at %08lx irq %ld\n",
273                         (unsigned long)rtc->regs, rtc->irq);
274
275         return 0;
276
277 out_free_irq:
278         platform_set_drvdata(pdev, NULL);
279         free_irq(irq, rtc);
280 out_iounmap:
281         iounmap(rtc->regs);
282 out:
283         kfree(rtc);
284         return ret;
285 }
286
287 static int __exit at32_rtc_remove(struct platform_device *pdev)
288 {
289         struct rtc_at32ap700x *rtc = platform_get_drvdata(pdev);
290
291         device_init_wakeup(&pdev->dev, 0);
292
293         free_irq(rtc->irq, rtc);
294         iounmap(rtc->regs);
295         rtc_device_unregister(rtc->rtc);
296         kfree(rtc);
297         platform_set_drvdata(pdev, NULL);
298
299         return 0;
300 }
301
302 MODULE_ALIAS("platform:at32ap700x_rtc");
303
304 static struct platform_driver at32_rtc_driver = {
305         .remove         = __exit_p(at32_rtc_remove),
306         .driver         = {
307                 .name   = "at32ap700x_rtc",
308                 .owner  = THIS_MODULE,
309         },
310 };
311
312 static int __init at32_rtc_init(void)
313 {
314         return platform_driver_probe(&at32_rtc_driver, at32_rtc_probe);
315 }
316 module_init(at32_rtc_init);
317
318 static void __exit at32_rtc_exit(void)
319 {
320         platform_driver_unregister(&at32_rtc_driver);
321 }
322 module_exit(at32_rtc_exit);
323
324 MODULE_AUTHOR("Hans-Christian Egtvedt <hcegtvedt@atmel.com>");
325 MODULE_DESCRIPTION("Real time clock for AVR32 AT32AP700x");
326 MODULE_LICENSE("GPL");