Commit | Line | Data |
---|---|---|
fa04e78b HCE |
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 | ||
fa04e78b HCE |
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"); | |
8d431dbe | 233 | goto out; |
fa04e78b HCE |
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 | ||
8d431dbe DB |
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 | ||
fa04e78b HCE |
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); | |
8d431dbe | 261 | goto out_free_irq; |
fa04e78b HCE |
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 | ||
fa04e78b HCE |
271 | out_free_irq: |
272 | free_irq(irq, rtc); | |
8d431dbe DB |
273 | out_iounmap: |
274 | iounmap(rtc->regs); | |
fa04e78b HCE |
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 | ||
ad28a07b | 293 | MODULE_ALIAS("platform:at32ap700x_rtc"); |
fa04e78b HCE |
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"); |