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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
39struct rtc_plat_data {
40 struct rtc_device *rtc;
41 void __iomem *ioaddr;
42 int irq;
43 struct clk *clk;
44};
45
46static 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
66static 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
97static 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
130static 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
170static 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
185static 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
200static const struct rtc_class_ops mv_rtc_ops = {
201 .read_time = mv_rtc_read_time,
202 .set_time = mv_rtc_set_time,
203};
204
205static const struct rtc_class_ops mv_rtc_alarm_ops = {
206 .read_time = mv_rtc_read_time,
207 .set_time = mv_rtc_set_time,
208 .read_alarm = mv_rtc_read_alarm,
209 .set_alarm = mv_rtc_set_alarm,
210 .alarm_irq_enable = mv_rtc_alarm_irq_enable,
211};
212
213static int __init mv_rtc_probe(struct platform_device *pdev)
214{
215 struct resource *res;
216 struct rtc_plat_data *pdata;
217 u32 rtc_time;
218 int ret = 0;
219
220 pdata = devm_kzalloc(&pdev->dev, sizeof(*pdata), GFP_KERNEL);
221 if (!pdata)
222 return -ENOMEM;
223
224 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
225 pdata->ioaddr = devm_ioremap_resource(&pdev->dev, res);
226 if (IS_ERR(pdata->ioaddr))
227 return PTR_ERR(pdata->ioaddr);
228
229 pdata->clk = devm_clk_get(&pdev->dev, NULL);
230 /* Not all SoCs require a clock.*/
231 if (!IS_ERR(pdata->clk))
232 clk_prepare_enable(pdata->clk);
233
234 /* make sure the 24 hour mode is enabled */
235 rtc_time = readl(pdata->ioaddr + RTC_TIME_REG_OFFS);
236 if (rtc_time & RTC_HOURS_12H_MODE) {
237 dev_err(&pdev->dev, "12 Hour mode is enabled but not supported.\n");
238 ret = -EINVAL;
239 goto out;
240 }
241
242 /* make sure it is actually functional */
243 if (rtc_time == 0x01000000) {
244 ssleep(1);
245 rtc_time = readl(pdata->ioaddr + RTC_TIME_REG_OFFS);
246 if (rtc_time == 0x01000000) {
247 dev_err(&pdev->dev, "internal RTC not ticking\n");
248 ret = -ENODEV;
249 goto out;
250 }
251 }
252
253 pdata->irq = platform_get_irq(pdev, 0);
254
255 platform_set_drvdata(pdev, pdata);
256
257 pdata->rtc = devm_rtc_allocate_device(&pdev->dev);
258 if (IS_ERR(pdata->rtc)) {
259 ret = PTR_ERR(pdata->rtc);
260 goto out;
261 }
262
263 if (pdata->irq >= 0) {
264 writel(0, pdata->ioaddr + RTC_ALARM_INTERRUPT_MASK_REG_OFFS);
265 if (devm_request_irq(&pdev->dev, pdata->irq, mv_rtc_interrupt,
266 IRQF_SHARED,
267 pdev->name, pdata) < 0) {
268 dev_warn(&pdev->dev, "interrupt not available.\n");
269 pdata->irq = -1;
270 }
271 }
272
273 if (pdata->irq >= 0) {
274 device_init_wakeup(&pdev->dev, 1);
275 pdata->rtc->ops = &mv_rtc_alarm_ops;
276 } else {
277 pdata->rtc->ops = &mv_rtc_ops;
278 }
279
280 pdata->rtc->range_min = RTC_TIMESTAMP_BEGIN_2000;
281 pdata->rtc->range_max = RTC_TIMESTAMP_END_2099;
282
283 ret = rtc_register_device(pdata->rtc);
284 if (!ret)
285 return 0;
286out:
287 if (!IS_ERR(pdata->clk))
288 clk_disable_unprepare(pdata->clk);
289
290 return ret;
291}
292
293static int __exit mv_rtc_remove(struct platform_device *pdev)
294{
295 struct rtc_plat_data *pdata = platform_get_drvdata(pdev);
296
297 if (pdata->irq >= 0)
298 device_init_wakeup(&pdev->dev, 0);
299
300 if (!IS_ERR(pdata->clk))
301 clk_disable_unprepare(pdata->clk);
302
303 return 0;
304}
305
306#ifdef CONFIG_OF
307static const struct of_device_id rtc_mv_of_match_table[] = {
308 { .compatible = "marvell,orion-rtc", },
309 {}
310};
311MODULE_DEVICE_TABLE(of, rtc_mv_of_match_table);
312#endif
313
314static struct platform_driver mv_rtc_driver = {
315 .remove = __exit_p(mv_rtc_remove),
316 .driver = {
317 .name = "rtc-mv",
318 .of_match_table = of_match_ptr(rtc_mv_of_match_table),
319 },
320};
321
322module_platform_driver_probe(mv_rtc_driver, mv_rtc_probe);
323
324MODULE_AUTHOR("Saeed Bishara <saeed@marvell.com>");
325MODULE_DESCRIPTION("Marvell RTC driver");
326MODULE_LICENSE("GPL");
327MODULE_ALIAS("platform:rtc-mv");