Revert "Merge commit 'main-jb-2012.08.03-B4' into t114-0806"
[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_alarm_irq_enable(struct device *dev, unsigned int enabled)
138 {
139         struct rtc_at32ap700x *rtc = dev_get_drvdata(dev);
140         int ret = 0;
141
142         spin_lock_irq(&rtc->lock);
143
144         if(enabled) {
145                 if (rtc_readl(rtc, VAL) > rtc->alarm_time) {
146                         ret = -EINVAL;
147                         goto out;
148                 }
149                 rtc_writel(rtc, CTRL, rtc_readl(rtc, CTRL)
150                                 | RTC_BIT(CTRL_TOPEN));
151                 rtc_writel(rtc, ICR, RTC_BIT(ICR_TOPI));
152                 rtc_writel(rtc, IER, RTC_BIT(IER_TOPI));
153         } else {
154                 rtc_writel(rtc, CTRL, rtc_readl(rtc, CTRL)
155                                 & ~RTC_BIT(CTRL_TOPEN));
156                 rtc_writel(rtc, IDR, RTC_BIT(IDR_TOPI));
157                 rtc_writel(rtc, ICR, RTC_BIT(ICR_TOPI));
158         }
159 out:
160         spin_unlock_irq(&rtc->lock);
161
162         return ret;
163 }
164
165 static irqreturn_t at32_rtc_interrupt(int irq, void *dev_id)
166 {
167         struct rtc_at32ap700x *rtc = (struct rtc_at32ap700x *)dev_id;
168         unsigned long isr = rtc_readl(rtc, ISR);
169         unsigned long events = 0;
170         int ret = IRQ_NONE;
171
172         spin_lock(&rtc->lock);
173
174         if (isr & RTC_BIT(ISR_TOPI)) {
175                 rtc_writel(rtc, ICR, RTC_BIT(ICR_TOPI));
176                 rtc_writel(rtc, IDR, RTC_BIT(IDR_TOPI));
177                 rtc_writel(rtc, CTRL, rtc_readl(rtc, CTRL)
178                                 & ~RTC_BIT(CTRL_TOPEN));
179                 rtc_writel(rtc, VAL, rtc->alarm_time);
180                 events = RTC_AF | RTC_IRQF;
181                 rtc_update_irq(rtc->rtc, 1, events);
182                 ret = IRQ_HANDLED;
183         }
184
185         spin_unlock(&rtc->lock);
186
187         return ret;
188 }
189
190 static struct rtc_class_ops at32_rtc_ops = {
191         .read_time      = at32_rtc_readtime,
192         .set_time       = at32_rtc_settime,
193         .read_alarm     = at32_rtc_readalarm,
194         .set_alarm      = at32_rtc_setalarm,
195         .alarm_irq_enable = at32_rtc_alarm_irq_enable,
196 };
197
198 static int __init at32_rtc_probe(struct platform_device *pdev)
199 {
200         struct resource *regs;
201         struct rtc_at32ap700x *rtc;
202         int irq;
203         int ret;
204
205         rtc = kzalloc(sizeof(struct rtc_at32ap700x), GFP_KERNEL);
206         if (!rtc) {
207                 dev_dbg(&pdev->dev, "out of memory\n");
208                 return -ENOMEM;
209         }
210
211         regs = platform_get_resource(pdev, IORESOURCE_MEM, 0);
212         if (!regs) {
213                 dev_dbg(&pdev->dev, "no mmio resource defined\n");
214                 ret = -ENXIO;
215                 goto out;
216         }
217
218         irq = platform_get_irq(pdev, 0);
219         if (irq <= 0) {
220                 dev_dbg(&pdev->dev, "could not get irq\n");
221                 ret = -ENXIO;
222                 goto out;
223         }
224
225         rtc->irq = irq;
226         rtc->regs = ioremap(regs->start, resource_size(regs));
227         if (!rtc->regs) {
228                 ret = -ENOMEM;
229                 dev_dbg(&pdev->dev, "could not map I/O memory\n");
230                 goto out;
231         }
232         spin_lock_init(&rtc->lock);
233
234         /*
235          * Maybe init RTC: count from zero at 1 Hz, disable wrap irq.
236          *
237          * Do not reset VAL register, as it can hold an old time
238          * from last JTAG reset.
239          */
240         if (!(rtc_readl(rtc, CTRL) & RTC_BIT(CTRL_EN))) {
241                 rtc_writel(rtc, CTRL, RTC_BIT(CTRL_PCLR));
242                 rtc_writel(rtc, IDR, RTC_BIT(IDR_TOPI));
243                 rtc_writel(rtc, CTRL, RTC_BF(CTRL_PSEL, 0xe)
244                                 | RTC_BIT(CTRL_EN));
245         }
246
247         ret = request_irq(irq, at32_rtc_interrupt, IRQF_SHARED, "rtc", rtc);
248         if (ret) {
249                 dev_dbg(&pdev->dev, "could not request irq %d\n", irq);
250                 goto out_iounmap;
251         }
252
253         platform_set_drvdata(pdev, rtc);
254
255         rtc->rtc = rtc_device_register(pdev->name, &pdev->dev,
256                                 &at32_rtc_ops, THIS_MODULE);
257         if (IS_ERR(rtc->rtc)) {
258                 dev_dbg(&pdev->dev, "could not register rtc device\n");
259                 ret = PTR_ERR(rtc->rtc);
260                 goto out_free_irq;
261         }
262
263         device_init_wakeup(&pdev->dev, 1);
264
265         dev_info(&pdev->dev, "Atmel RTC for AT32AP700x at %08lx irq %ld\n",
266                         (unsigned long)rtc->regs, rtc->irq);
267
268         return 0;
269
270 out_free_irq:
271         platform_set_drvdata(pdev, NULL);
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         device_init_wakeup(&pdev->dev, 0);
285
286         free_irq(rtc->irq, rtc);
287         iounmap(rtc->regs);
288         rtc_device_unregister(rtc->rtc);
289         kfree(rtc);
290         platform_set_drvdata(pdev, NULL);
291
292         return 0;
293 }
294
295 MODULE_ALIAS("platform:at32ap700x_rtc");
296
297 static struct platform_driver at32_rtc_driver = {
298         .remove         = __exit_p(at32_rtc_remove),
299         .driver         = {
300                 .name   = "at32ap700x_rtc",
301                 .owner  = THIS_MODULE,
302         },
303 };
304
305 static int __init at32_rtc_init(void)
306 {
307         return platform_driver_probe(&at32_rtc_driver, at32_rtc_probe);
308 }
309 module_init(at32_rtc_init);
310
311 static void __exit at32_rtc_exit(void)
312 {
313         platform_driver_unregister(&at32_rtc_driver);
314 }
315 module_exit(at32_rtc_exit);
316
317 MODULE_AUTHOR("Hans-Christian Egtvedt <hcegtvedt@atmel.com>");
318 MODULE_DESCRIPTION("Real time clock for AVR32 AT32AP700x");
319 MODULE_LICENSE("GPL");