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