1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
|
/*
* An RTC driver for the AVR32 AT32AP700x processor series.
*
* Copyright (C) 2007 Atmel Corporation
*
* This program is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 2 as published
* by the Free Software Foundation.
*/
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/platform_device.h>
#include <linux/slab.h>
#include <linux/rtc.h>
#include <linux/io.h>
/*
* This is a bare-bones RTC. It runs during most system sleep states, but has
* no battery backup and gets reset during system restart. It must be
* initialized from an external clock (network, I2C, etc) before it can be of
* much use.
*
* The alarm functionality is limited by the hardware, not supporting
* periodic interrupts.
*/
#define RTC_CTRL 0x00
#define RTC_CTRL_EN 0
#define RTC_CTRL_PCLR 1
#define RTC_CTRL_TOPEN 2
#define RTC_CTRL_PSEL 8
#define RTC_VAL 0x04
#define RTC_TOP 0x08
#define RTC_IER 0x10
#define RTC_IER_TOPI 0
#define RTC_IDR 0x14
#define RTC_IDR_TOPI 0
#define RTC_IMR 0x18
#define RTC_IMR_TOPI 0
#define RTC_ISR 0x1c
#define RTC_ISR_TOPI 0
#define RTC_ICR 0x20
#define RTC_ICR_TOPI 0
#define RTC_BIT(name) (1 << RTC_##name)
#define RTC_BF(name, value) ((value) << RTC_##name)
#define rtc_readl(dev, reg) \
__raw_readl((dev)->regs + RTC_##reg)
#define rtc_writel(dev, reg, value) \
__raw_writel((value), (dev)->regs + RTC_##reg)
struct rtc_at32ap700x {
struct rtc_device *rtc;
void __iomem *regs;
unsigned long alarm_time;
unsigned long irq;
/* Protect against concurrent register access. */
spinlock_t lock;
};
static int at32_rtc_readtime(struct device *dev, struct rtc_time *tm)
{
struct rtc_at32ap700x *rtc = dev_get_drvdata(dev);
unsigned long now;
now = rtc_readl(rtc, VAL);
rtc_time_to_tm(now, tm);
return 0;
}
static int at32_rtc_settime(struct device *dev, struct rtc_time *tm)
{
struct rtc_at32ap700x *rtc = dev_get_drvdata(dev);
unsigned long now;
int ret;
ret = rtc_tm_to_time(tm, &now);
if (ret == 0)
rtc_writel(rtc, VAL, now);
return ret;
}
static int at32_rtc_readalarm(struct device *dev, struct rtc_wkalrm *alrm)
{
struct rtc_at32ap700x *rtc = dev_get_drvdata(dev);
spin_lock_irq(&rtc->lock);
rtc_time_to_tm(rtc->alarm_time, &alrm->time);
alrm->enabled = rtc_readl(rtc, IMR) & RTC_BIT(IMR_TOPI) ? 1 : 0;
alrm->pending = rtc_readl(rtc, ISR) & RTC_BIT(ISR_TOPI) ? 1 : 0;
spin_unlock_irq(&rtc->lock);
return 0;
}
static int at32_rtc_setalarm(struct device *dev, struct rtc_wkalrm *alrm)
{
struct rtc_at32ap700x *rtc = dev_get_drvdata(dev);
unsigned long rtc_unix_time;
unsigned long alarm_unix_time;
int ret;
rtc_unix_time = rtc_readl(rtc, VAL);
ret = rtc_tm_to_time(&alrm->time, &alarm_unix_time);
if (ret)
return ret;
if (alarm_unix_time < rtc_unix_time)
return -EINVAL;
spin_lock_irq(&rtc->lock);
rtc->alarm_time = alarm_unix_time;
rtc_writel(rtc, TOP, rtc->alarm_time);
if (alrm->enabled)
rtc_writel(rtc, CTRL, rtc_readl(rtc, CTRL)
| RTC_BIT(CTRL_TOPEN));
else
rtc_writel(rtc, CTRL, rtc_readl(rtc, CTRL)
& ~RTC_BIT(CTRL_TOPEN));
spin_unlock_irq(&rtc->lock);
return ret;
}
static int at32_rtc_alarm_irq_enable(struct device *dev, unsigned int enabled)
{
struct rtc_at32ap700x *rtc = dev_get_drvdata(dev);
int ret = 0;
spin_lock_irq(&rtc->lock);
if(enabled) {
if (rtc_readl(rtc, VAL) > rtc->alarm_time) {
ret = -EINVAL;
goto out;
}
rtc_writel(rtc, CTRL, rtc_readl(rtc, CTRL)
| RTC_BIT(CTRL_TOPEN));
rtc_writel(rtc, ICR, RTC_BIT(ICR_TOPI));
rtc_writel(rtc, IER, RTC_BIT(IER_TOPI));
} else {
rtc_writel(rtc, CTRL, rtc_readl(rtc, CTRL)
& ~RTC_BIT(CTRL_TOPEN));
rtc_writel(rtc, IDR, RTC_BIT(IDR_TOPI));
rtc_writel(rtc, ICR, RTC_BIT(ICR_TOPI));
}
out:
spin_unlock_irq(&rtc->lock);
return ret;
}
static irqreturn_t at32_rtc_interrupt(int irq, void *dev_id)
{
struct rtc_at32ap700x *rtc = (struct rtc_at32ap700x *)dev_id;
unsigned long isr = rtc_readl(rtc, ISR);
unsigned long events = 0;
int ret = IRQ_NONE;
spin_lock(&rtc->lock);
if (isr & RTC_BIT(ISR_TOPI)) {
rtc_writel(rtc, ICR, RTC_BIT(ICR_TOPI));
rtc_writel(rtc, IDR, RTC_BIT(IDR_TOPI));
rtc_writel(rtc, CTRL, rtc_readl(rtc, CTRL)
& ~RTC_BIT(CTRL_TOPEN));
rtc_writel(rtc, VAL, rtc->alarm_time);
events = RTC_AF | RTC_IRQF;
rtc_update_irq(rtc->rtc, 1, events);
ret = IRQ_HANDLED;
}
spin_unlock(&rtc->lock);
return ret;
}
static struct rtc_class_ops at32_rtc_ops = {
.read_time = at32_rtc_readtime,
.set_time = at32_rtc_settime,
.read_alarm = at32_rtc_readalarm,
.set_alarm = at32_rtc_setalarm,
.alarm_irq_enable = at32_rtc_alarm_irq_enable,
};
static int __init at32_rtc_probe(struct platform_device *pdev)
{
struct resource *regs;
struct rtc_at32ap700x *rtc;
int irq;
int ret;
rtc = devm_kzalloc(&pdev->dev, sizeof(struct rtc_at32ap700x),
GFP_KERNEL);
if (!rtc) {
dev_dbg(&pdev->dev, "out of memory\n");
return -ENOMEM;
}
regs = platform_get_resource(pdev, IORESOURCE_MEM, 0);
if (!regs) {
dev_dbg(&pdev->dev, "no mmio resource defined\n");
ret = -ENXIO;
goto out;
}
irq = platform_get_irq(pdev, 0);
if (irq <= 0) {
dev_dbg(&pdev->dev, "could not get irq\n");
ret = -ENXIO;
goto out;
}
rtc->irq = irq;
rtc->regs = devm_ioremap(&pdev->dev, regs->start, resource_size(regs));
if (!rtc->regs) {
ret = -ENOMEM;
dev_dbg(&pdev->dev, "could not map I/O memory\n");
goto out;
}
spin_lock_init(&rtc->lock);
/*
* Maybe init RTC: count from zero at 1 Hz, disable wrap irq.
*
* Do not reset VAL register, as it can hold an old time
* from last JTAG reset.
*/
if (!(rtc_readl(rtc, CTRL) & RTC_BIT(CTRL_EN))) {
rtc_writel(rtc, CTRL, RTC_BIT(CTRL_PCLR));
rtc_writel(rtc, IDR, RTC_BIT(IDR_TOPI));
rtc_writel(rtc, CTRL, RTC_BF(CTRL_PSEL, 0xe)
| RTC_BIT(CTRL_EN));
}
ret = devm_request_irq(&pdev->dev, irq, at32_rtc_interrupt, IRQF_SHARED,
"rtc", rtc);
if (ret) {
dev_dbg(&pdev->dev, "could not request irq %d\n", irq);
goto out;
}
platform_set_drvdata(pdev, rtc);
rtc->rtc = devm_rtc_device_register(&pdev->dev, pdev->name,
&at32_rtc_ops, THIS_MODULE);
if (IS_ERR(rtc->rtc)) {
dev_dbg(&pdev->dev, "could not register rtc device\n");
ret = PTR_ERR(rtc->rtc);
goto out;
}
device_init_wakeup(&pdev->dev, 1);
dev_info(&pdev->dev, "Atmel RTC for AT32AP700x at %08lx irq %ld\n",
(unsigned long)rtc->regs, rtc->irq);
return 0;
out:
platform_set_drvdata(pdev, NULL);
return ret;
}
static int __exit at32_rtc_remove(struct platform_device *pdev)
{
device_init_wakeup(&pdev->dev, 0);
platform_set_drvdata(pdev, NULL);
return 0;
}
MODULE_ALIAS("platform:at32ap700x_rtc");
static struct platform_driver at32_rtc_driver = {
.remove = __exit_p(at32_rtc_remove),
.driver = {
.name = "at32ap700x_rtc",
.owner = THIS_MODULE,
},
};
module_platform_driver_probe(at32_rtc_driver, at32_rtc_probe);
MODULE_AUTHOR("Hans-Christian Egtvedt <hcegtvedt@atmel.com>");
MODULE_DESCRIPTION("Real time clock for AVR32 AT32AP700x");
MODULE_LICENSE("GPL");
|
