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18#include <linux/module.h>
19#include <linux/rtc.h>
20#include <linux/init.h>
21#include <linux/interrupt.h>
22#include <linux/io.h>
23#include <linux/bcd.h>
24#include <linux/platform_device.h>
25#include <linux/slab.h>
26#include <linux/of.h>
27
28
29
30
31#define VT8500_RTC_TS 0x00
32#define VT8500_RTC_DS 0x04
33#define VT8500_RTC_AS 0x08
34#define VT8500_RTC_CR 0x0c
35#define VT8500_RTC_TR 0x10
36#define VT8500_RTC_DR 0x14
37#define VT8500_RTC_WS 0x18
38#define VT8500_RTC_CL 0x20
39#define VT8500_RTC_IS 0x24
40#define VT8500_RTC_ST 0x28
41
42#define INVALID_TIME_BIT (1 << 31)
43
44#define DATE_CENTURY_S 19
45#define DATE_YEAR_S 11
46#define DATE_YEAR_MASK (0xff << DATE_YEAR_S)
47#define DATE_MONTH_S 6
48#define DATE_MONTH_MASK (0x1f << DATE_MONTH_S)
49#define DATE_DAY_MASK 0x3f
50
51#define TIME_DOW_S 20
52#define TIME_DOW_MASK (0x07 << TIME_DOW_S)
53#define TIME_HOUR_S 14
54#define TIME_HOUR_MASK (0x3f << TIME_HOUR_S)
55#define TIME_MIN_S 7
56#define TIME_MIN_MASK (0x7f << TIME_MIN_S)
57#define TIME_SEC_MASK 0x7f
58
59#define ALARM_DAY_S 20
60#define ALARM_DAY_MASK (0x3f << ALARM_DAY_S)
61
62#define ALARM_DAY_BIT (1 << 29)
63#define ALARM_HOUR_BIT (1 << 28)
64#define ALARM_MIN_BIT (1 << 27)
65#define ALARM_SEC_BIT (1 << 26)
66
67#define ALARM_ENABLE_MASK (ALARM_DAY_BIT \
68 | ALARM_HOUR_BIT \
69 | ALARM_MIN_BIT \
70 | ALARM_SEC_BIT)
71
72#define VT8500_RTC_CR_ENABLE (1 << 0)
73#define VT8500_RTC_CR_12H (1 << 1)
74#define VT8500_RTC_CR_SM_ENABLE (1 << 2)
75#define VT8500_RTC_CR_SM_SEC (1 << 3)
76#define VT8500_RTC_CR_CALIB (1 << 4)
77
78#define VT8500_RTC_IS_ALARM (1 << 0)
79
80struct vt8500_rtc {
81 void __iomem *regbase;
82 int irq_alarm;
83 struct rtc_device *rtc;
84 spinlock_t lock;
85};
86
87static irqreturn_t vt8500_rtc_irq(int irq, void *dev_id)
88{
89 struct vt8500_rtc *vt8500_rtc = dev_id;
90 u32 isr;
91 unsigned long events = 0;
92
93 spin_lock(&vt8500_rtc->lock);
94
95
96 isr = readl(vt8500_rtc->regbase + VT8500_RTC_IS);
97 writel(isr, vt8500_rtc->regbase + VT8500_RTC_IS);
98
99 spin_unlock(&vt8500_rtc->lock);
100
101 if (isr & VT8500_RTC_IS_ALARM)
102 events |= RTC_AF | RTC_IRQF;
103
104 rtc_update_irq(vt8500_rtc->rtc, 1, events);
105
106 return IRQ_HANDLED;
107}
108
109static int vt8500_rtc_read_time(struct device *dev, struct rtc_time *tm)
110{
111 struct vt8500_rtc *vt8500_rtc = dev_get_drvdata(dev);
112 u32 date, time;
113
114 date = readl(vt8500_rtc->regbase + VT8500_RTC_DR);
115 time = readl(vt8500_rtc->regbase + VT8500_RTC_TR);
116
117 tm->tm_sec = bcd2bin(time & TIME_SEC_MASK);
118 tm->tm_min = bcd2bin((time & TIME_MIN_MASK) >> TIME_MIN_S);
119 tm->tm_hour = bcd2bin((time & TIME_HOUR_MASK) >> TIME_HOUR_S);
120 tm->tm_mday = bcd2bin(date & DATE_DAY_MASK);
121 tm->tm_mon = bcd2bin((date & DATE_MONTH_MASK) >> DATE_MONTH_S) - 1;
122 tm->tm_year = bcd2bin((date & DATE_YEAR_MASK) >> DATE_YEAR_S)
123 + ((date >> DATE_CENTURY_S) & 1 ? 200 : 100);
124 tm->tm_wday = (time & TIME_DOW_MASK) >> TIME_DOW_S;
125
126 return 0;
127}
128
129static int vt8500_rtc_set_time(struct device *dev, struct rtc_time *tm)
130{
131 struct vt8500_rtc *vt8500_rtc = dev_get_drvdata(dev);
132
133 if (tm->tm_year < 100) {
134 dev_warn(dev, "Only years 2000-2199 are supported by the "
135 "hardware!\n");
136 return -EINVAL;
137 }
138
139 writel((bin2bcd(tm->tm_year % 100) << DATE_YEAR_S)
140 | (bin2bcd(tm->tm_mon + 1) << DATE_MONTH_S)
141 | (bin2bcd(tm->tm_mday))
142 | ((tm->tm_year >= 200) << DATE_CENTURY_S),
143 vt8500_rtc->regbase + VT8500_RTC_DS);
144 writel((bin2bcd(tm->tm_wday) << TIME_DOW_S)
145 | (bin2bcd(tm->tm_hour) << TIME_HOUR_S)
146 | (bin2bcd(tm->tm_min) << TIME_MIN_S)
147 | (bin2bcd(tm->tm_sec)),
148 vt8500_rtc->regbase + VT8500_RTC_TS);
149
150 return 0;
151}
152
153static int vt8500_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alrm)
154{
155 struct vt8500_rtc *vt8500_rtc = dev_get_drvdata(dev);
156 u32 isr, alarm;
157
158 alarm = readl(vt8500_rtc->regbase + VT8500_RTC_AS);
159 isr = readl(vt8500_rtc->regbase + VT8500_RTC_IS);
160
161 alrm->time.tm_mday = bcd2bin((alarm & ALARM_DAY_MASK) >> ALARM_DAY_S);
162 alrm->time.tm_hour = bcd2bin((alarm & TIME_HOUR_MASK) >> TIME_HOUR_S);
163 alrm->time.tm_min = bcd2bin((alarm & TIME_MIN_MASK) >> TIME_MIN_S);
164 alrm->time.tm_sec = bcd2bin((alarm & TIME_SEC_MASK));
165
166 alrm->enabled = (alarm & ALARM_ENABLE_MASK) ? 1 : 0;
167 alrm->pending = (isr & VT8500_RTC_IS_ALARM) ? 1 : 0;
168
169 return rtc_valid_tm(&alrm->time);
170}
171
172static int vt8500_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm)
173{
174 struct vt8500_rtc *vt8500_rtc = dev_get_drvdata(dev);
175
176 writel((alrm->enabled ? ALARM_ENABLE_MASK : 0)
177 | (bin2bcd(alrm->time.tm_mday) << ALARM_DAY_S)
178 | (bin2bcd(alrm->time.tm_hour) << TIME_HOUR_S)
179 | (bin2bcd(alrm->time.tm_min) << TIME_MIN_S)
180 | (bin2bcd(alrm->time.tm_sec)),
181 vt8500_rtc->regbase + VT8500_RTC_AS);
182
183 return 0;
184}
185
186static int vt8500_alarm_irq_enable(struct device *dev, unsigned int enabled)
187{
188 struct vt8500_rtc *vt8500_rtc = dev_get_drvdata(dev);
189 unsigned long tmp = readl(vt8500_rtc->regbase + VT8500_RTC_AS);
190
191 if (enabled)
192 tmp |= ALARM_ENABLE_MASK;
193 else
194 tmp &= ~ALARM_ENABLE_MASK;
195
196 writel(tmp, vt8500_rtc->regbase + VT8500_RTC_AS);
197 return 0;
198}
199
200static const struct rtc_class_ops vt8500_rtc_ops = {
201 .read_time = vt8500_rtc_read_time,
202 .set_time = vt8500_rtc_set_time,
203 .read_alarm = vt8500_rtc_read_alarm,
204 .set_alarm = vt8500_rtc_set_alarm,
205 .alarm_irq_enable = vt8500_alarm_irq_enable,
206};
207
208static int vt8500_rtc_probe(struct platform_device *pdev)
209{
210 struct vt8500_rtc *vt8500_rtc;
211 struct resource *res;
212 int ret;
213
214 vt8500_rtc = devm_kzalloc(&pdev->dev,
215 sizeof(struct vt8500_rtc), GFP_KERNEL);
216 if (!vt8500_rtc)
217 return -ENOMEM;
218
219 spin_lock_init(&vt8500_rtc->lock);
220 platform_set_drvdata(pdev, vt8500_rtc);
221
222 vt8500_rtc->irq_alarm = platform_get_irq(pdev, 0);
223 if (vt8500_rtc->irq_alarm < 0) {
224 dev_err(&pdev->dev, "No alarm IRQ resource defined\n");
225 return vt8500_rtc->irq_alarm;
226 }
227
228 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
229 vt8500_rtc->regbase = devm_ioremap_resource(&pdev->dev, res);
230 if (IS_ERR(vt8500_rtc->regbase))
231 return PTR_ERR(vt8500_rtc->regbase);
232
233
234 writel(VT8500_RTC_CR_ENABLE,
235 vt8500_rtc->regbase + VT8500_RTC_CR);
236
237 vt8500_rtc->rtc = devm_rtc_device_register(&pdev->dev, "vt8500-rtc",
238 &vt8500_rtc_ops, THIS_MODULE);
239 if (IS_ERR(vt8500_rtc->rtc)) {
240 ret = PTR_ERR(vt8500_rtc->rtc);
241 dev_err(&pdev->dev,
242 "Failed to register RTC device -> %d\n", ret);
243 goto err_return;
244 }
245
246 ret = devm_request_irq(&pdev->dev, vt8500_rtc->irq_alarm,
247 vt8500_rtc_irq, 0, "rtc alarm", vt8500_rtc);
248 if (ret < 0) {
249 dev_err(&pdev->dev, "can't get irq %i, err %d\n",
250 vt8500_rtc->irq_alarm, ret);
251 goto err_return;
252 }
253
254 return 0;
255
256err_return:
257 return ret;
258}
259
260static int vt8500_rtc_remove(struct platform_device *pdev)
261{
262 struct vt8500_rtc *vt8500_rtc = platform_get_drvdata(pdev);
263
264
265 writel(0, vt8500_rtc->regbase + VT8500_RTC_IS);
266
267 return 0;
268}
269
270static const struct of_device_id wmt_dt_ids[] = {
271 { .compatible = "via,vt8500-rtc", },
272 {}
273};
274MODULE_DEVICE_TABLE(of, wmt_dt_ids);
275
276static struct platform_driver vt8500_rtc_driver = {
277 .probe = vt8500_rtc_probe,
278 .remove = vt8500_rtc_remove,
279 .driver = {
280 .name = "vt8500-rtc",
281 .of_match_table = wmt_dt_ids,
282 },
283};
284
285module_platform_driver(vt8500_rtc_driver);
286
287MODULE_AUTHOR("Alexey Charkov <alchark@gmail.com>");
288MODULE_DESCRIPTION("VIA VT8500 SoC Realtime Clock Driver (RTC)");
289MODULE_LICENSE("GPL v2");
290MODULE_ALIAS("platform:vt8500-rtc");
291
