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10#include <linux/module.h>
11#include <linux/rtc.h>
12#include <linux/init.h>
13#include <linux/interrupt.h>
14#include <linux/io.h>
15#include <linux/bcd.h>
16#include <linux/platform_device.h>
17#include <linux/slab.h>
18#include <linux/of.h>
19
20
21
22
23#define VT8500_RTC_TS 0x00
24#define VT8500_RTC_DS 0x04
25#define VT8500_RTC_AS 0x08
26#define VT8500_RTC_CR 0x0c
27#define VT8500_RTC_TR 0x10
28#define VT8500_RTC_DR 0x14
29#define VT8500_RTC_WS 0x18
30#define VT8500_RTC_CL 0x20
31#define VT8500_RTC_IS 0x24
32#define VT8500_RTC_ST 0x28
33
34#define INVALID_TIME_BIT (1 << 31)
35
36#define DATE_CENTURY_S 19
37#define DATE_YEAR_S 11
38#define DATE_YEAR_MASK (0xff << DATE_YEAR_S)
39#define DATE_MONTH_S 6
40#define DATE_MONTH_MASK (0x1f << DATE_MONTH_S)
41#define DATE_DAY_MASK 0x3f
42
43#define TIME_DOW_S 20
44#define TIME_DOW_MASK (0x07 << TIME_DOW_S)
45#define TIME_HOUR_S 14
46#define TIME_HOUR_MASK (0x3f << TIME_HOUR_S)
47#define TIME_MIN_S 7
48#define TIME_MIN_MASK (0x7f << TIME_MIN_S)
49#define TIME_SEC_MASK 0x7f
50
51#define ALARM_DAY_S 20
52#define ALARM_DAY_MASK (0x3f << ALARM_DAY_S)
53
54#define ALARM_DAY_BIT (1 << 29)
55#define ALARM_HOUR_BIT (1 << 28)
56#define ALARM_MIN_BIT (1 << 27)
57#define ALARM_SEC_BIT (1 << 26)
58
59#define ALARM_ENABLE_MASK (ALARM_DAY_BIT \
60 | ALARM_HOUR_BIT \
61 | ALARM_MIN_BIT \
62 | ALARM_SEC_BIT)
63
64#define VT8500_RTC_CR_ENABLE (1 << 0)
65#define VT8500_RTC_CR_12H (1 << 1)
66#define VT8500_RTC_CR_SM_ENABLE (1 << 2)
67#define VT8500_RTC_CR_SM_SEC (1 << 3)
68#define VT8500_RTC_CR_CALIB (1 << 4)
69
70#define VT8500_RTC_IS_ALARM (1 << 0)
71
72struct vt8500_rtc {
73 void __iomem *regbase;
74 int irq_alarm;
75 struct rtc_device *rtc;
76 spinlock_t lock;
77};
78
79static irqreturn_t vt8500_rtc_irq(int irq, void *dev_id)
80{
81 struct vt8500_rtc *vt8500_rtc = dev_id;
82 u32 isr;
83 unsigned long events = 0;
84
85 spin_lock(&vt8500_rtc->lock);
86
87
88 isr = readl(vt8500_rtc->regbase + VT8500_RTC_IS);
89 writel(isr, vt8500_rtc->regbase + VT8500_RTC_IS);
90
91 spin_unlock(&vt8500_rtc->lock);
92
93 if (isr & VT8500_RTC_IS_ALARM)
94 events |= RTC_AF | RTC_IRQF;
95
96 rtc_update_irq(vt8500_rtc->rtc, 1, events);
97
98 return IRQ_HANDLED;
99}
100
101static int vt8500_rtc_read_time(struct device *dev, struct rtc_time *tm)
102{
103 struct vt8500_rtc *vt8500_rtc = dev_get_drvdata(dev);
104 u32 date, time;
105
106 date = readl(vt8500_rtc->regbase + VT8500_RTC_DR);
107 time = readl(vt8500_rtc->regbase + VT8500_RTC_TR);
108
109 tm->tm_sec = bcd2bin(time & TIME_SEC_MASK);
110 tm->tm_min = bcd2bin((time & TIME_MIN_MASK) >> TIME_MIN_S);
111 tm->tm_hour = bcd2bin((time & TIME_HOUR_MASK) >> TIME_HOUR_S);
112 tm->tm_mday = bcd2bin(date & DATE_DAY_MASK);
113 tm->tm_mon = bcd2bin((date & DATE_MONTH_MASK) >> DATE_MONTH_S) - 1;
114 tm->tm_year = bcd2bin((date & DATE_YEAR_MASK) >> DATE_YEAR_S)
115 + ((date >> DATE_CENTURY_S) & 1 ? 200 : 100);
116 tm->tm_wday = (time & TIME_DOW_MASK) >> TIME_DOW_S;
117
118 return 0;
119}
120
121static int vt8500_rtc_set_time(struct device *dev, struct rtc_time *tm)
122{
123 struct vt8500_rtc *vt8500_rtc = dev_get_drvdata(dev);
124
125 if (tm->tm_year < 100) {
126 dev_warn(dev, "Only years 2000-2199 are supported by the "
127 "hardware!\n");
128 return -EINVAL;
129 }
130
131 writel((bin2bcd(tm->tm_year % 100) << DATE_YEAR_S)
132 | (bin2bcd(tm->tm_mon + 1) << DATE_MONTH_S)
133 | (bin2bcd(tm->tm_mday))
134 | ((tm->tm_year >= 200) << DATE_CENTURY_S),
135 vt8500_rtc->regbase + VT8500_RTC_DS);
136 writel((bin2bcd(tm->tm_wday) << TIME_DOW_S)
137 | (bin2bcd(tm->tm_hour) << TIME_HOUR_S)
138 | (bin2bcd(tm->tm_min) << TIME_MIN_S)
139 | (bin2bcd(tm->tm_sec)),
140 vt8500_rtc->regbase + VT8500_RTC_TS);
141
142 return 0;
143}
144
145static int vt8500_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alrm)
146{
147 struct vt8500_rtc *vt8500_rtc = dev_get_drvdata(dev);
148 u32 isr, alarm;
149
150 alarm = readl(vt8500_rtc->regbase + VT8500_RTC_AS);
151 isr = readl(vt8500_rtc->regbase + VT8500_RTC_IS);
152
153 alrm->time.tm_mday = bcd2bin((alarm & ALARM_DAY_MASK) >> ALARM_DAY_S);
154 alrm->time.tm_hour = bcd2bin((alarm & TIME_HOUR_MASK) >> TIME_HOUR_S);
155 alrm->time.tm_min = bcd2bin((alarm & TIME_MIN_MASK) >> TIME_MIN_S);
156 alrm->time.tm_sec = bcd2bin((alarm & TIME_SEC_MASK));
157
158 alrm->enabled = (alarm & ALARM_ENABLE_MASK) ? 1 : 0;
159 alrm->pending = (isr & VT8500_RTC_IS_ALARM) ? 1 : 0;
160
161 return rtc_valid_tm(&alrm->time);
162}
163
164static int vt8500_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm)
165{
166 struct vt8500_rtc *vt8500_rtc = dev_get_drvdata(dev);
167
168 writel((alrm->enabled ? ALARM_ENABLE_MASK : 0)
169 | (bin2bcd(alrm->time.tm_mday) << ALARM_DAY_S)
170 | (bin2bcd(alrm->time.tm_hour) << TIME_HOUR_S)
171 | (bin2bcd(alrm->time.tm_min) << TIME_MIN_S)
172 | (bin2bcd(alrm->time.tm_sec)),
173 vt8500_rtc->regbase + VT8500_RTC_AS);
174
175 return 0;
176}
177
178static int vt8500_alarm_irq_enable(struct device *dev, unsigned int enabled)
179{
180 struct vt8500_rtc *vt8500_rtc = dev_get_drvdata(dev);
181 unsigned long tmp = readl(vt8500_rtc->regbase + VT8500_RTC_AS);
182
183 if (enabled)
184 tmp |= ALARM_ENABLE_MASK;
185 else
186 tmp &= ~ALARM_ENABLE_MASK;
187
188 writel(tmp, vt8500_rtc->regbase + VT8500_RTC_AS);
189 return 0;
190}
191
192static const struct rtc_class_ops vt8500_rtc_ops = {
193 .read_time = vt8500_rtc_read_time,
194 .set_time = vt8500_rtc_set_time,
195 .read_alarm = vt8500_rtc_read_alarm,
196 .set_alarm = vt8500_rtc_set_alarm,
197 .alarm_irq_enable = vt8500_alarm_irq_enable,
198};
199
200static int vt8500_rtc_probe(struct platform_device *pdev)
201{
202 struct vt8500_rtc *vt8500_rtc;
203 struct resource *res;
204 int ret;
205
206 vt8500_rtc = devm_kzalloc(&pdev->dev,
207 sizeof(struct vt8500_rtc), GFP_KERNEL);
208 if (!vt8500_rtc)
209 return -ENOMEM;
210
211 spin_lock_init(&vt8500_rtc->lock);
212 platform_set_drvdata(pdev, vt8500_rtc);
213
214 vt8500_rtc->irq_alarm = platform_get_irq(pdev, 0);
215 if (vt8500_rtc->irq_alarm < 0) {
216 dev_err(&pdev->dev, "No alarm IRQ resource defined\n");
217 return vt8500_rtc->irq_alarm;
218 }
219
220 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
221 vt8500_rtc->regbase = devm_ioremap_resource(&pdev->dev, res);
222 if (IS_ERR(vt8500_rtc->regbase))
223 return PTR_ERR(vt8500_rtc->regbase);
224
225
226 writel(VT8500_RTC_CR_ENABLE,
227 vt8500_rtc->regbase + VT8500_RTC_CR);
228
229 vt8500_rtc->rtc = devm_rtc_device_register(&pdev->dev, "vt8500-rtc",
230 &vt8500_rtc_ops, THIS_MODULE);
231 if (IS_ERR(vt8500_rtc->rtc)) {
232 ret = PTR_ERR(vt8500_rtc->rtc);
233 dev_err(&pdev->dev,
234 "Failed to register RTC device -> %d\n", ret);
235 goto err_return;
236 }
237
238 ret = devm_request_irq(&pdev->dev, vt8500_rtc->irq_alarm,
239 vt8500_rtc_irq, 0, "rtc alarm", vt8500_rtc);
240 if (ret < 0) {
241 dev_err(&pdev->dev, "can't get irq %i, err %d\n",
242 vt8500_rtc->irq_alarm, ret);
243 goto err_return;
244 }
245
246 return 0;
247
248err_return:
249 return ret;
250}
251
252static int vt8500_rtc_remove(struct platform_device *pdev)
253{
254 struct vt8500_rtc *vt8500_rtc = platform_get_drvdata(pdev);
255
256
257 writel(0, vt8500_rtc->regbase + VT8500_RTC_IS);
258
259 return 0;
260}
261
262static const struct of_device_id wmt_dt_ids[] = {
263 { .compatible = "via,vt8500-rtc", },
264 {}
265};
266MODULE_DEVICE_TABLE(of, wmt_dt_ids);
267
268static struct platform_driver vt8500_rtc_driver = {
269 .probe = vt8500_rtc_probe,
270 .remove = vt8500_rtc_remove,
271 .driver = {
272 .name = "vt8500-rtc",
273 .of_match_table = wmt_dt_ids,
274 },
275};
276
277module_platform_driver(vt8500_rtc_driver);
278
279MODULE_AUTHOR("Alexey Charkov <alchark@gmail.com>");
280MODULE_DESCRIPTION("VIA VT8500 SoC Realtime Clock Driver (RTC)");
281MODULE_LICENSE("GPL v2");
282MODULE_ALIAS("platform:vt8500-rtc");
283
