Version:  2.0.40 2.2.26 2.4.37 3.6 3.7 3.8 3.9 3.10 3.11 3.12 3.13 3.14 3.15 3.16 3.17 3.18 3.19 4.0 4.1 4.2

Linux/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 #endif
328 
329 static struct platform_driver mv_rtc_driver = {
330         .remove         = __exit_p(mv_rtc_remove),
331         .driver         = {
332                 .name   = "rtc-mv",
333                 .of_match_table = of_match_ptr(rtc_mv_of_match_table),
334         },
335 };
336 
337 module_platform_driver_probe(mv_rtc_driver, mv_rtc_probe);
338 
339 MODULE_AUTHOR("Saeed Bishara <saeed@marvell.com>");
340 MODULE_DESCRIPTION("Marvell RTC driver");
341 MODULE_LICENSE("GPL");
342 MODULE_ALIAS("platform:rtc-mv");
343 

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