rtc: rtc-s35390a.c needs the bitreverse library
[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         rtc_time_to_tm(rtc->alarm_time, &alrm->time);
98         alrm->pending = rtc_readl(rtc, IMR) & RTC_BIT(IMR_TOPI) ? 1 : 0;
99
100         return 0;
101 }
102
103 static int at32_rtc_setalarm(struct device *dev, struct rtc_wkalrm *alrm)
104 {
105         struct rtc_at32ap700x *rtc = dev_get_drvdata(dev);
106         unsigned long rtc_unix_time;
107         unsigned long alarm_unix_time;
108         int ret;
109
110         rtc_unix_time = rtc_readl(rtc, VAL);
111
112         ret = rtc_tm_to_time(&alrm->time, &alarm_unix_time);
113         if (ret)
114                 return ret;
115
116         if (alarm_unix_time < rtc_unix_time)
117                 return -EINVAL;
118
119         spin_lock_irq(&rtc->lock);
120         rtc->alarm_time = alarm_unix_time;
121         rtc_writel(rtc, TOP, rtc->alarm_time);
122         if (alrm->pending)
123                 rtc_writel(rtc, CTRL, rtc_readl(rtc, CTRL)
124                                 | RTC_BIT(CTRL_TOPEN));
125         else
126                 rtc_writel(rtc, CTRL, rtc_readl(rtc, CTRL)
127                                 & ~RTC_BIT(CTRL_TOPEN));
128         spin_unlock_irq(&rtc->lock);
129
130         return ret;
131 }
132
133 static int at32_rtc_ioctl(struct device *dev, unsigned int cmd,
134                         unsigned long arg)
135 {
136         struct rtc_at32ap700x *rtc = dev_get_drvdata(dev);
137         int ret = 0;
138
139         spin_lock_irq(&rtc->lock);
140
141         switch (cmd) {
142         case RTC_AIE_ON:
143                 if (rtc_readl(rtc, VAL) > rtc->alarm_time) {
144                         ret = -EINVAL;
145                         break;
146                 }
147                 rtc_writel(rtc, CTRL, rtc_readl(rtc, CTRL)
148                                 | RTC_BIT(CTRL_TOPEN));
149                 rtc_writel(rtc, ICR, RTC_BIT(ICR_TOPI));
150                 rtc_writel(rtc, IER, RTC_BIT(IER_TOPI));
151                 break;
152         case RTC_AIE_OFF:
153                 rtc_writel(rtc, CTRL, rtc_readl(rtc, CTRL)
154                                 & ~RTC_BIT(CTRL_TOPEN));
155                 rtc_writel(rtc, IDR, RTC_BIT(IDR_TOPI));
156                 rtc_writel(rtc, ICR, RTC_BIT(ICR_TOPI));
157                 break;
158         default:
159                 ret = -ENOIOCTLCMD;
160                 break;
161         }
162
163         spin_unlock_irq(&rtc->lock);
164
165         return ret;
166 }
167
168 static irqreturn_t at32_rtc_interrupt(int irq, void *dev_id)
169 {
170         struct rtc_at32ap700x *rtc = (struct rtc_at32ap700x *)dev_id;
171         unsigned long isr = rtc_readl(rtc, ISR);
172         unsigned long events = 0;
173         int ret = IRQ_NONE;
174
175         spin_lock(&rtc->lock);
176
177         if (isr & RTC_BIT(ISR_TOPI)) {
178                 rtc_writel(rtc, ICR, RTC_BIT(ICR_TOPI));
179                 rtc_writel(rtc, IDR, RTC_BIT(IDR_TOPI));
180                 rtc_writel(rtc, CTRL, rtc_readl(rtc, CTRL)
181                                 & ~RTC_BIT(CTRL_TOPEN));
182                 rtc_writel(rtc, VAL, rtc->alarm_time);
183                 events = RTC_AF | RTC_IRQF;
184                 rtc_update_irq(rtc->rtc, 1, events);
185                 ret = IRQ_HANDLED;
186         }
187
188         spin_unlock(&rtc->lock);
189
190         return ret;
191 }
192
193 static struct rtc_class_ops at32_rtc_ops = {
194         .ioctl          = at32_rtc_ioctl,
195         .read_time      = at32_rtc_readtime,
196         .set_time       = at32_rtc_settime,
197         .read_alarm     = at32_rtc_readalarm,
198         .set_alarm      = at32_rtc_setalarm,
199 };
200
201 static int __init at32_rtc_probe(struct platform_device *pdev)
202 {
203         struct resource *regs;
204         struct rtc_at32ap700x *rtc;
205         int irq = -1;
206         int ret;
207
208         rtc = kzalloc(sizeof(struct rtc_at32ap700x), GFP_KERNEL);
209         if (!rtc) {
210                 dev_dbg(&pdev->dev, "out of memory\n");
211                 return -ENOMEM;
212         }
213
214         regs = platform_get_resource(pdev, IORESOURCE_MEM, 0);
215         if (!regs) {
216                 dev_dbg(&pdev->dev, "no mmio resource defined\n");
217                 ret = -ENXIO;
218                 goto out;
219         }
220
221         irq = platform_get_irq(pdev, 0);
222         if (irq < 0) {
223                 dev_dbg(&pdev->dev, "could not get irq\n");
224                 ret = -ENXIO;
225                 goto out;
226         }
227
228         rtc->irq = irq;
229         rtc->regs = ioremap(regs->start, regs->end - regs->start + 1);
230         if (!rtc->regs) {
231                 ret = -ENOMEM;
232                 dev_dbg(&pdev->dev, "could not map I/O memory\n");
233                 goto out;
234         }
235         spin_lock_init(&rtc->lock);
236
237         /*
238          * Maybe init RTC: count from zero at 1 Hz, disable wrap irq.
239          *
240          * Do not reset VAL register, as it can hold an old time
241          * from last JTAG reset.
242          */
243         if (!(rtc_readl(rtc, CTRL) & RTC_BIT(CTRL_EN))) {
244                 rtc_writel(rtc, CTRL, RTC_BIT(CTRL_PCLR));
245                 rtc_writel(rtc, IDR, RTC_BIT(IDR_TOPI));
246                 rtc_writel(rtc, CTRL, RTC_BF(CTRL_PSEL, 0xe)
247                                 | RTC_BIT(CTRL_EN));
248         }
249
250         ret = request_irq(irq, at32_rtc_interrupt, IRQF_SHARED, "rtc", rtc);
251         if (ret) {
252                 dev_dbg(&pdev->dev, "could not request irq %d\n", irq);
253                 goto out_iounmap;
254         }
255
256         rtc->rtc = rtc_device_register(pdev->name, &pdev->dev,
257                                 &at32_rtc_ops, THIS_MODULE);
258         if (IS_ERR(rtc->rtc)) {
259                 dev_dbg(&pdev->dev, "could not register rtc device\n");
260                 ret = PTR_ERR(rtc->rtc);
261                 goto out_free_irq;
262         }
263
264         platform_set_drvdata(pdev, rtc);
265
266         dev_info(&pdev->dev, "Atmel RTC for AT32AP700x at %08lx irq %ld\n",
267                         (unsigned long)rtc->regs, rtc->irq);
268
269         return 0;
270
271 out_free_irq:
272         free_irq(irq, rtc);
273 out_iounmap:
274         iounmap(rtc->regs);
275 out:
276         kfree(rtc);
277         return ret;
278 }
279
280 static int __exit at32_rtc_remove(struct platform_device *pdev)
281 {
282         struct rtc_at32ap700x *rtc = platform_get_drvdata(pdev);
283
284         free_irq(rtc->irq, rtc);
285         iounmap(rtc->regs);
286         rtc_device_unregister(rtc->rtc);
287         kfree(rtc);
288         platform_set_drvdata(pdev, NULL);
289
290         return 0;
291 }
292
293 MODULE_ALIAS("at32ap700x_rtc");
294
295 static struct platform_driver at32_rtc_driver = {
296         .remove         = __exit_p(at32_rtc_remove),
297         .driver         = {
298                 .name   = "at32ap700x_rtc",
299                 .owner  = THIS_MODULE,
300         },
301 };
302
303 static int __init at32_rtc_init(void)
304 {
305         return platform_driver_probe(&at32_rtc_driver, at32_rtc_probe);
306 }
307 module_init(at32_rtc_init);
308
309 static void __exit at32_rtc_exit(void)
310 {
311         platform_driver_unregister(&at32_rtc_driver);
312 }
313 module_exit(at32_rtc_exit);
314
315 MODULE_AUTHOR("Hans-Christian Egtvedt <hcegtvedt@atmel.com>");
316 MODULE_DESCRIPTION("Real time clock for AVR32 AT32AP700x");
317 MODULE_LICENSE("GPL");