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UBUNTU: Ubuntu-4.15.0-96.97
[mirror_ubuntu-bionic-kernel.git] / drivers / rtc / rtc-mv.c
1 /*
2 * Driver for the RTC in Marvell SoCs.
3 *
4 * This file is licensed under the terms of the GNU General Public
5 * License version 2. This program is licensed "as is" without any
6 * warranty of any kind, whether express or implied.
7 */
8
9 #include <linux/init.h>
10 #include <linux/kernel.h>
11 #include <linux/rtc.h>
12 #include <linux/bcd.h>
13 #include <linux/bitops.h>
14 #include <linux/io.h>
15 #include <linux/platform_device.h>
16 #include <linux/of.h>
17 #include <linux/delay.h>
18 #include <linux/clk.h>
19 #include <linux/gfp.h>
20 #include <linux/module.h>
21
22
23 #define RTC_TIME_REG_OFFS 0
24 #define RTC_SECONDS_OFFS 0
25 #define RTC_MINUTES_OFFS 8
26 #define RTC_HOURS_OFFS 16
27 #define RTC_WDAY_OFFS 24
28 #define RTC_HOURS_12H_MODE BIT(22) /* 12 hour mode */
29
30 #define RTC_DATE_REG_OFFS 4
31 #define RTC_MDAY_OFFS 0
32 #define RTC_MONTH_OFFS 8
33 #define RTC_YEAR_OFFS 16
34
35 #define RTC_ALARM_TIME_REG_OFFS 8
36 #define RTC_ALARM_DATE_REG_OFFS 0xc
37 #define RTC_ALARM_VALID BIT(7)
38
39 #define RTC_ALARM_INTERRUPT_MASK_REG_OFFS 0x10
40 #define RTC_ALARM_INTERRUPT_CASUE_REG_OFFS 0x14
41
42 struct rtc_plat_data {
43 struct rtc_device *rtc;
44 void __iomem *ioaddr;
45 int irq;
46 struct clk *clk;
47 };
48
49 static int mv_rtc_set_time(struct device *dev, struct rtc_time *tm)
50 {
51 struct rtc_plat_data *pdata = dev_get_drvdata(dev);
52 void __iomem *ioaddr = pdata->ioaddr;
53 u32 rtc_reg;
54
55 rtc_reg = (bin2bcd(tm->tm_sec) << RTC_SECONDS_OFFS) |
56 (bin2bcd(tm->tm_min) << RTC_MINUTES_OFFS) |
57 (bin2bcd(tm->tm_hour) << RTC_HOURS_OFFS) |
58 (bin2bcd(tm->tm_wday) << RTC_WDAY_OFFS);
59 writel(rtc_reg, ioaddr + RTC_TIME_REG_OFFS);
60
61 rtc_reg = (bin2bcd(tm->tm_mday) << RTC_MDAY_OFFS) |
62 (bin2bcd(tm->tm_mon + 1) << RTC_MONTH_OFFS) |
63 (bin2bcd(tm->tm_year % 100) << RTC_YEAR_OFFS);
64 writel(rtc_reg, ioaddr + RTC_DATE_REG_OFFS);
65
66 return 0;
67 }
68
69 static int mv_rtc_read_time(struct device *dev, struct rtc_time *tm)
70 {
71 struct rtc_plat_data *pdata = dev_get_drvdata(dev);
72 void __iomem *ioaddr = pdata->ioaddr;
73 u32 rtc_time, rtc_date;
74 unsigned int year, month, day, hour, minute, second, wday;
75
76 rtc_time = readl(ioaddr + RTC_TIME_REG_OFFS);
77 rtc_date = readl(ioaddr + RTC_DATE_REG_OFFS);
78
79 second = rtc_time & 0x7f;
80 minute = (rtc_time >> RTC_MINUTES_OFFS) & 0x7f;
81 hour = (rtc_time >> RTC_HOURS_OFFS) & 0x3f; /* assume 24 hour mode */
82 wday = (rtc_time >> RTC_WDAY_OFFS) & 0x7;
83
84 day = rtc_date & 0x3f;
85 month = (rtc_date >> RTC_MONTH_OFFS) & 0x3f;
86 year = (rtc_date >> RTC_YEAR_OFFS) & 0xff;
87
88 tm->tm_sec = bcd2bin(second);
89 tm->tm_min = bcd2bin(minute);
90 tm->tm_hour = bcd2bin(hour);
91 tm->tm_mday = bcd2bin(day);
92 tm->tm_wday = bcd2bin(wday);
93 tm->tm_mon = bcd2bin(month) - 1;
94 /* hw counts from year 2000, but tm_year is relative to 1900 */
95 tm->tm_year = bcd2bin(year) + 100;
96
97 return rtc_valid_tm(tm);
98 }
99
100 static int mv_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alm)
101 {
102 struct rtc_plat_data *pdata = dev_get_drvdata(dev);
103 void __iomem *ioaddr = pdata->ioaddr;
104 u32 rtc_time, rtc_date;
105 unsigned int year, month, day, hour, minute, second, wday;
106
107 rtc_time = readl(ioaddr + RTC_ALARM_TIME_REG_OFFS);
108 rtc_date = readl(ioaddr + RTC_ALARM_DATE_REG_OFFS);
109
110 second = rtc_time & 0x7f;
111 minute = (rtc_time >> RTC_MINUTES_OFFS) & 0x7f;
112 hour = (rtc_time >> RTC_HOURS_OFFS) & 0x3f; /* assume 24 hour mode */
113 wday = (rtc_time >> RTC_WDAY_OFFS) & 0x7;
114
115 day = rtc_date & 0x3f;
116 month = (rtc_date >> RTC_MONTH_OFFS) & 0x3f;
117 year = (rtc_date >> RTC_YEAR_OFFS) & 0xff;
118
119 alm->time.tm_sec = bcd2bin(second);
120 alm->time.tm_min = bcd2bin(minute);
121 alm->time.tm_hour = bcd2bin(hour);
122 alm->time.tm_mday = bcd2bin(day);
123 alm->time.tm_wday = bcd2bin(wday);
124 alm->time.tm_mon = bcd2bin(month) - 1;
125 /* hw counts from year 2000, but tm_year is relative to 1900 */
126 alm->time.tm_year = bcd2bin(year) + 100;
127
128 if (rtc_valid_tm(&alm->time) < 0) {
129 dev_err(dev, "retrieved alarm date/time is not valid.\n");
130 rtc_time_to_tm(0, &alm->time);
131 }
132
133 alm->enabled = !!readl(ioaddr + RTC_ALARM_INTERRUPT_MASK_REG_OFFS);
134 return 0;
135 }
136
137 static int mv_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alm)
138 {
139 struct rtc_plat_data *pdata = dev_get_drvdata(dev);
140 void __iomem *ioaddr = pdata->ioaddr;
141 u32 rtc_reg = 0;
142
143 if (alm->time.tm_sec >= 0)
144 rtc_reg |= (RTC_ALARM_VALID | bin2bcd(alm->time.tm_sec))
145 << RTC_SECONDS_OFFS;
146 if (alm->time.tm_min >= 0)
147 rtc_reg |= (RTC_ALARM_VALID | bin2bcd(alm->time.tm_min))
148 << RTC_MINUTES_OFFS;
149 if (alm->time.tm_hour >= 0)
150 rtc_reg |= (RTC_ALARM_VALID | bin2bcd(alm->time.tm_hour))
151 << RTC_HOURS_OFFS;
152
153 writel(rtc_reg, ioaddr + RTC_ALARM_TIME_REG_OFFS);
154
155 if (alm->time.tm_mday >= 0)
156 rtc_reg = (RTC_ALARM_VALID | bin2bcd(alm->time.tm_mday))
157 << RTC_MDAY_OFFS;
158 else
159 rtc_reg = 0;
160
161 if (alm->time.tm_mon >= 0)
162 rtc_reg |= (RTC_ALARM_VALID | bin2bcd(alm->time.tm_mon + 1))
163 << RTC_MONTH_OFFS;
164
165 if (alm->time.tm_year >= 0)
166 rtc_reg |= (RTC_ALARM_VALID | bin2bcd(alm->time.tm_year % 100))
167 << RTC_YEAR_OFFS;
168
169 writel(rtc_reg, ioaddr + RTC_ALARM_DATE_REG_OFFS);
170 writel(0, ioaddr + RTC_ALARM_INTERRUPT_CASUE_REG_OFFS);
171 writel(alm->enabled ? 1 : 0,
172 ioaddr + RTC_ALARM_INTERRUPT_MASK_REG_OFFS);
173
174 return 0;
175 }
176
177 static int mv_rtc_alarm_irq_enable(struct device *dev, unsigned int enabled)
178 {
179 struct platform_device *pdev = to_platform_device(dev);
180 struct rtc_plat_data *pdata = platform_get_drvdata(pdev);
181 void __iomem *ioaddr = pdata->ioaddr;
182
183 if (pdata->irq < 0)
184 return -EINVAL; /* fall back into rtc-dev's emulation */
185
186 if (enabled)
187 writel(1, ioaddr + RTC_ALARM_INTERRUPT_MASK_REG_OFFS);
188 else
189 writel(0, ioaddr + RTC_ALARM_INTERRUPT_MASK_REG_OFFS);
190 return 0;
191 }
192
193 static irqreturn_t mv_rtc_interrupt(int irq, void *data)
194 {
195 struct rtc_plat_data *pdata = data;
196 void __iomem *ioaddr = pdata->ioaddr;
197
198 /* alarm irq? */
199 if (!readl(ioaddr + RTC_ALARM_INTERRUPT_CASUE_REG_OFFS))
200 return IRQ_NONE;
201
202 /* clear interrupt */
203 writel(0, ioaddr + RTC_ALARM_INTERRUPT_CASUE_REG_OFFS);
204 rtc_update_irq(pdata->rtc, 1, RTC_IRQF | RTC_AF);
205 return IRQ_HANDLED;
206 }
207
208 static const struct rtc_class_ops mv_rtc_ops = {
209 .read_time = mv_rtc_read_time,
210 .set_time = mv_rtc_set_time,
211 };
212
213 static const struct rtc_class_ops mv_rtc_alarm_ops = {
214 .read_time = mv_rtc_read_time,
215 .set_time = mv_rtc_set_time,
216 .read_alarm = mv_rtc_read_alarm,
217 .set_alarm = mv_rtc_set_alarm,
218 .alarm_irq_enable = mv_rtc_alarm_irq_enable,
219 };
220
221 static int __init mv_rtc_probe(struct platform_device *pdev)
222 {
223 struct resource *res;
224 struct rtc_plat_data *pdata;
225 u32 rtc_time;
226 u32 rtc_date;
227 int ret = 0;
228
229 pdata = devm_kzalloc(&pdev->dev, sizeof(*pdata), GFP_KERNEL);
230 if (!pdata)
231 return -ENOMEM;
232
233 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
234 pdata->ioaddr = devm_ioremap_resource(&pdev->dev, res);
235 if (IS_ERR(pdata->ioaddr))
236 return PTR_ERR(pdata->ioaddr);
237
238 pdata->clk = devm_clk_get(&pdev->dev, NULL);
239 /* Not all SoCs require a clock.*/
240 if (!IS_ERR(pdata->clk))
241 clk_prepare_enable(pdata->clk);
242
243 /* make sure the 24 hour mode is enabled */
244 rtc_time = readl(pdata->ioaddr + RTC_TIME_REG_OFFS);
245 if (rtc_time & RTC_HOURS_12H_MODE) {
246 dev_err(&pdev->dev, "12 Hour mode is enabled but not supported.\n");
247 ret = -EINVAL;
248 goto out;
249 }
250
251 /* make sure it is actually functional */
252 if (rtc_time == 0x01000000) {
253 ssleep(1);
254 rtc_time = readl(pdata->ioaddr + RTC_TIME_REG_OFFS);
255 if (rtc_time == 0x01000000) {
256 dev_err(&pdev->dev, "internal RTC not ticking\n");
257 ret = -ENODEV;
258 goto out;
259 }
260 }
261
262 /*
263 * A date after January 19th, 2038 does not fit on 32 bits and
264 * will confuse the kernel and userspace. Reset to a sane date
265 * (January 1st, 2013) if we're after 2038.
266 */
267 rtc_date = readl(pdata->ioaddr + RTC_DATE_REG_OFFS);
268 if (bcd2bin((rtc_date >> RTC_YEAR_OFFS) & 0xff) >= 38) {
269 dev_info(&pdev->dev, "invalid RTC date, resetting to January 1st, 2013\n");
270 writel(0x130101, pdata->ioaddr + RTC_DATE_REG_OFFS);
271 }
272
273 pdata->irq = platform_get_irq(pdev, 0);
274
275 platform_set_drvdata(pdev, pdata);
276
277 if (pdata->irq >= 0) {
278 device_init_wakeup(&pdev->dev, 1);
279 pdata->rtc = devm_rtc_device_register(&pdev->dev, pdev->name,
280 &mv_rtc_alarm_ops,
281 THIS_MODULE);
282 } else {
283 pdata->rtc = devm_rtc_device_register(&pdev->dev, pdev->name,
284 &mv_rtc_ops, THIS_MODULE);
285 }
286 if (IS_ERR(pdata->rtc)) {
287 ret = PTR_ERR(pdata->rtc);
288 goto out;
289 }
290
291 if (pdata->irq >= 0) {
292 writel(0, pdata->ioaddr + RTC_ALARM_INTERRUPT_MASK_REG_OFFS);
293 if (devm_request_irq(&pdev->dev, pdata->irq, mv_rtc_interrupt,
294 IRQF_SHARED,
295 pdev->name, pdata) < 0) {
296 dev_warn(&pdev->dev, "interrupt not available.\n");
297 pdata->irq = -1;
298 }
299 }
300
301 return 0;
302 out:
303 if (!IS_ERR(pdata->clk))
304 clk_disable_unprepare(pdata->clk);
305
306 return ret;
307 }
308
309 static int __exit mv_rtc_remove(struct platform_device *pdev)
310 {
311 struct rtc_plat_data *pdata = platform_get_drvdata(pdev);
312
313 if (pdata->irq >= 0)
314 device_init_wakeup(&pdev->dev, 0);
315
316 if (!IS_ERR(pdata->clk))
317 clk_disable_unprepare(pdata->clk);
318
319 return 0;
320 }
321
322 #ifdef CONFIG_OF
323 static const struct of_device_id rtc_mv_of_match_table[] = {
324 { .compatible = "marvell,orion-rtc", },
325 {}
326 };
327 MODULE_DEVICE_TABLE(of, rtc_mv_of_match_table);
328 #endif
329
330 static struct platform_driver mv_rtc_driver = {
331 .remove = __exit_p(mv_rtc_remove),
332 .driver = {
333 .name = "rtc-mv",
334 .of_match_table = of_match_ptr(rtc_mv_of_match_table),
335 },
336 };
337
338 module_platform_driver_probe(mv_rtc_driver, mv_rtc_probe);
339
340 MODULE_AUTHOR("Saeed Bishara <saeed@marvell.com>");
341 MODULE_DESCRIPTION("Marvell RTC driver");
342 MODULE_LICENSE("GPL");
343 MODULE_ALIAS("platform:rtc-mv");