1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * Driver for the RTC in Marvell SoCs.
4 */
5
6 #include <linux/init.h>
7 #include <linux/kernel.h>
8 #include <linux/rtc.h>
9 #include <linux/bcd.h>
10 #include <linux/bitops.h>
11 #include <linux/io.h>
12 #include <linux/platform_device.h>
13 #include <linux/of.h>
14 #include <linux/delay.h>
15 #include <linux/clk.h>
16 #include <linux/gfp.h>
17 #include <linux/module.h>
18
19
20 #define RTC_TIME_REG_OFFS 0
21 #define RTC_SECONDS_OFFS 0
22 #define RTC_MINUTES_OFFS 8
23 #define RTC_HOURS_OFFS 16
24 #define RTC_WDAY_OFFS 24
25 #define RTC_HOURS_12H_MODE BIT(22) /* 12 hour mode */
26
27 #define RTC_DATE_REG_OFFS 4
28 #define RTC_MDAY_OFFS 0
29 #define RTC_MONTH_OFFS 8
30 #define RTC_YEAR_OFFS 16
31
32 #define RTC_ALARM_TIME_REG_OFFS 8
33 #define RTC_ALARM_DATE_REG_OFFS 0xc
34 #define RTC_ALARM_VALID BIT(7)
35
36 #define RTC_ALARM_INTERRUPT_MASK_REG_OFFS 0x10
37 #define RTC_ALARM_INTERRUPT_CASUE_REG_OFFS 0x14
38
39 struct rtc_plat_data {
40 struct rtc_device *rtc;
41 void __iomem *ioaddr;
42 int irq;
43 struct clk *clk;
44 };
45
mv_rtc_set_time(struct device * dev,struct rtc_time * tm)46 static int mv_rtc_set_time(struct device *dev, struct rtc_time *tm)
47 {
48 struct rtc_plat_data *pdata = dev_get_drvdata(dev);
49 void __iomem *ioaddr = pdata->ioaddr;
50 u32 rtc_reg;
51
52 rtc_reg = (bin2bcd(tm->tm_sec) << RTC_SECONDS_OFFS) |
53 (bin2bcd(tm->tm_min) << RTC_MINUTES_OFFS) |
54 (bin2bcd(tm->tm_hour) << RTC_HOURS_OFFS) |
55 (bin2bcd(tm->tm_wday) << RTC_WDAY_OFFS);
56 writel(rtc_reg, ioaddr + RTC_TIME_REG_OFFS);
57
58 rtc_reg = (bin2bcd(tm->tm_mday) << RTC_MDAY_OFFS) |
59 (bin2bcd(tm->tm_mon + 1) << RTC_MONTH_OFFS) |
60 (bin2bcd(tm->tm_year - 100) << RTC_YEAR_OFFS);
61 writel(rtc_reg, ioaddr + RTC_DATE_REG_OFFS);
62
63 return 0;
64 }
65
mv_rtc_read_time(struct device * dev,struct rtc_time * tm)66 static int mv_rtc_read_time(struct device *dev, struct rtc_time *tm)
67 {
68 struct rtc_plat_data *pdata = dev_get_drvdata(dev);
69 void __iomem *ioaddr = pdata->ioaddr;
70 u32 rtc_time, rtc_date;
71 unsigned int year, month, day, hour, minute, second, wday;
72
73 rtc_time = readl(ioaddr + RTC_TIME_REG_OFFS);
74 rtc_date = readl(ioaddr + RTC_DATE_REG_OFFS);
75
76 second = rtc_time & 0x7f;
77 minute = (rtc_time >> RTC_MINUTES_OFFS) & 0x7f;
78 hour = (rtc_time >> RTC_HOURS_OFFS) & 0x3f; /* assume 24 hour mode */
79 wday = (rtc_time >> RTC_WDAY_OFFS) & 0x7;
80
81 day = rtc_date & 0x3f;
82 month = (rtc_date >> RTC_MONTH_OFFS) & 0x3f;
83 year = (rtc_date >> RTC_YEAR_OFFS) & 0xff;
84
85 tm->tm_sec = bcd2bin(second);
86 tm->tm_min = bcd2bin(minute);
87 tm->tm_hour = bcd2bin(hour);
88 tm->tm_mday = bcd2bin(day);
89 tm->tm_wday = bcd2bin(wday);
90 tm->tm_mon = bcd2bin(month) - 1;
91 /* hw counts from year 2000, but tm_year is relative to 1900 */
92 tm->tm_year = bcd2bin(year) + 100;
93
94 return 0;
95 }
96
mv_rtc_read_alarm(struct device * dev,struct rtc_wkalrm * alm)97 static int mv_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alm)
98 {
99 struct rtc_plat_data *pdata = dev_get_drvdata(dev);
100 void __iomem *ioaddr = pdata->ioaddr;
101 u32 rtc_time, rtc_date;
102 unsigned int year, month, day, hour, minute, second, wday;
103
104 rtc_time = readl(ioaddr + RTC_ALARM_TIME_REG_OFFS);
105 rtc_date = readl(ioaddr + RTC_ALARM_DATE_REG_OFFS);
106
107 second = rtc_time & 0x7f;
108 minute = (rtc_time >> RTC_MINUTES_OFFS) & 0x7f;
109 hour = (rtc_time >> RTC_HOURS_OFFS) & 0x3f; /* assume 24 hour mode */
110 wday = (rtc_time >> RTC_WDAY_OFFS) & 0x7;
111
112 day = rtc_date & 0x3f;
113 month = (rtc_date >> RTC_MONTH_OFFS) & 0x3f;
114 year = (rtc_date >> RTC_YEAR_OFFS) & 0xff;
115
116 alm->time.tm_sec = bcd2bin(second);
117 alm->time.tm_min = bcd2bin(minute);
118 alm->time.tm_hour = bcd2bin(hour);
119 alm->time.tm_mday = bcd2bin(day);
120 alm->time.tm_wday = bcd2bin(wday);
121 alm->time.tm_mon = bcd2bin(month) - 1;
122 /* hw counts from year 2000, but tm_year is relative to 1900 */
123 alm->time.tm_year = bcd2bin(year) + 100;
124
125 alm->enabled = !!readl(ioaddr + RTC_ALARM_INTERRUPT_MASK_REG_OFFS);
126
127 return rtc_valid_tm(&alm->time);
128 }
129
mv_rtc_set_alarm(struct device * dev,struct rtc_wkalrm * alm)130 static int mv_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alm)
131 {
132 struct rtc_plat_data *pdata = dev_get_drvdata(dev);
133 void __iomem *ioaddr = pdata->ioaddr;
134 u32 rtc_reg = 0;
135
136 if (alm->time.tm_sec >= 0)
137 rtc_reg |= (RTC_ALARM_VALID | bin2bcd(alm->time.tm_sec))
138 << RTC_SECONDS_OFFS;
139 if (alm->time.tm_min >= 0)
140 rtc_reg |= (RTC_ALARM_VALID | bin2bcd(alm->time.tm_min))
141 << RTC_MINUTES_OFFS;
142 if (alm->time.tm_hour >= 0)
143 rtc_reg |= (RTC_ALARM_VALID | bin2bcd(alm->time.tm_hour))
144 << RTC_HOURS_OFFS;
145
146 writel(rtc_reg, ioaddr + RTC_ALARM_TIME_REG_OFFS);
147
148 if (alm->time.tm_mday >= 0)
149 rtc_reg = (RTC_ALARM_VALID | bin2bcd(alm->time.tm_mday))
150 << RTC_MDAY_OFFS;
151 else
152 rtc_reg = 0;
153
154 if (alm->time.tm_mon >= 0)
155 rtc_reg |= (RTC_ALARM_VALID | bin2bcd(alm->time.tm_mon + 1))
156 << RTC_MONTH_OFFS;
157
158 if (alm->time.tm_year >= 0)
159 rtc_reg |= (RTC_ALARM_VALID | bin2bcd(alm->time.tm_year - 100))
160 << RTC_YEAR_OFFS;
161
162 writel(rtc_reg, ioaddr + RTC_ALARM_DATE_REG_OFFS);
163 writel(0, ioaddr + RTC_ALARM_INTERRUPT_CASUE_REG_OFFS);
164 writel(alm->enabled ? 1 : 0,
165 ioaddr + RTC_ALARM_INTERRUPT_MASK_REG_OFFS);
166
167 return 0;
168 }
169
mv_rtc_alarm_irq_enable(struct device * dev,unsigned int enabled)170 static int mv_rtc_alarm_irq_enable(struct device *dev, unsigned int enabled)
171 {
172 struct rtc_plat_data *pdata = dev_get_drvdata(dev);
173 void __iomem *ioaddr = pdata->ioaddr;
174
175 if (pdata->irq < 0)
176 return -EINVAL; /* fall back into rtc-dev's emulation */
177
178 if (enabled)
179 writel(1, ioaddr + RTC_ALARM_INTERRUPT_MASK_REG_OFFS);
180 else
181 writel(0, ioaddr + RTC_ALARM_INTERRUPT_MASK_REG_OFFS);
182 return 0;
183 }
184
mv_rtc_interrupt(int irq,void * data)185 static irqreturn_t mv_rtc_interrupt(int irq, void *data)
186 {
187 struct rtc_plat_data *pdata = data;
188 void __iomem *ioaddr = pdata->ioaddr;
189
190 /* alarm irq? */
191 if (!readl(ioaddr + RTC_ALARM_INTERRUPT_CASUE_REG_OFFS))
192 return IRQ_NONE;
193
194 /* clear interrupt */
195 writel(0, ioaddr + RTC_ALARM_INTERRUPT_CASUE_REG_OFFS);
196 rtc_update_irq(pdata->rtc, 1, RTC_IRQF | RTC_AF);
197 return IRQ_HANDLED;
198 }
199
200 static const struct rtc_class_ops mv_rtc_ops = {
201 .read_time = mv_rtc_read_time,
202 .set_time = mv_rtc_set_time,
203 .read_alarm = mv_rtc_read_alarm,
204 .set_alarm = mv_rtc_set_alarm,
205 .alarm_irq_enable = mv_rtc_alarm_irq_enable,
206 };
207
mv_rtc_probe(struct platform_device * pdev)208 static int __init mv_rtc_probe(struct platform_device *pdev)
209 {
210 struct rtc_plat_data *pdata;
211 u32 rtc_time;
212 int ret = 0;
213
214 pdata = devm_kzalloc(&pdev->dev, sizeof(*pdata), GFP_KERNEL);
215 if (!pdata)
216 return -ENOMEM;
217
218 pdata->ioaddr = devm_platform_ioremap_resource(pdev, 0);
219 if (IS_ERR(pdata->ioaddr))
220 return PTR_ERR(pdata->ioaddr);
221
222 pdata->clk = devm_clk_get(&pdev->dev, NULL);
223 /* Not all SoCs require a clock.*/
224 if (!IS_ERR(pdata->clk))
225 clk_prepare_enable(pdata->clk);
226
227 /* make sure the 24 hour mode is enabled */
228 rtc_time = readl(pdata->ioaddr + RTC_TIME_REG_OFFS);
229 if (rtc_time & RTC_HOURS_12H_MODE) {
230 dev_err(&pdev->dev, "12 Hour mode is enabled but not supported.\n");
231 ret = -EINVAL;
232 goto out;
233 }
234
235 /* make sure it is actually functional */
236 if (rtc_time == 0x01000000) {
237 ssleep(1);
238 rtc_time = readl(pdata->ioaddr + RTC_TIME_REG_OFFS);
239 if (rtc_time == 0x01000000) {
240 dev_err(&pdev->dev, "internal RTC not ticking\n");
241 ret = -ENODEV;
242 goto out;
243 }
244 }
245
246 pdata->irq = platform_get_irq(pdev, 0);
247
248 platform_set_drvdata(pdev, pdata);
249
250 pdata->rtc = devm_rtc_allocate_device(&pdev->dev);
251 if (IS_ERR(pdata->rtc)) {
252 ret = PTR_ERR(pdata->rtc);
253 goto out;
254 }
255
256 if (pdata->irq >= 0) {
257 writel(0, pdata->ioaddr + RTC_ALARM_INTERRUPT_MASK_REG_OFFS);
258 if (devm_request_irq(&pdev->dev, pdata->irq, mv_rtc_interrupt,
259 IRQF_SHARED,
260 pdev->name, pdata) < 0) {
261 dev_warn(&pdev->dev, "interrupt not available.\n");
262 pdata->irq = -1;
263 }
264 }
265
266 if (pdata->irq >= 0)
267 device_init_wakeup(&pdev->dev, 1);
268 else
269 clear_bit(RTC_FEATURE_ALARM, pdata->rtc->features);
270
271 pdata->rtc->ops = &mv_rtc_ops;
272 pdata->rtc->range_min = RTC_TIMESTAMP_BEGIN_2000;
273 pdata->rtc->range_max = RTC_TIMESTAMP_END_2099;
274
275 ret = devm_rtc_register_device(pdata->rtc);
276 if (!ret)
277 return 0;
278 out:
279 if (!IS_ERR(pdata->clk))
280 clk_disable_unprepare(pdata->clk);
281
282 return ret;
283 }
284
mv_rtc_remove(struct platform_device * pdev)285 static int __exit mv_rtc_remove(struct platform_device *pdev)
286 {
287 struct rtc_plat_data *pdata = platform_get_drvdata(pdev);
288
289 if (pdata->irq >= 0)
290 device_init_wakeup(&pdev->dev, 0);
291
292 if (!IS_ERR(pdata->clk))
293 clk_disable_unprepare(pdata->clk);
294
295 return 0;
296 }
297
298 #ifdef CONFIG_OF
299 static const struct of_device_id rtc_mv_of_match_table[] = {
300 { .compatible = "marvell,orion-rtc", },
301 {}
302 };
303 MODULE_DEVICE_TABLE(of, rtc_mv_of_match_table);
304 #endif
305
306 static struct platform_driver mv_rtc_driver = {
307 .remove = __exit_p(mv_rtc_remove),
308 .driver = {
309 .name = "rtc-mv",
310 .of_match_table = of_match_ptr(rtc_mv_of_match_table),
311 },
312 };
313
314 module_platform_driver_probe(mv_rtc_driver, mv_rtc_probe);
315
316 MODULE_AUTHOR("Saeed Bishara <saeed@marvell.com>");
317 MODULE_DESCRIPTION("Marvell RTC driver");
318 MODULE_LICENSE("GPL");
319 MODULE_ALIAS("platform:rtc-mv");
320