Version:  2.0.40 2.2.26 2.4.37 3.1 3.2 3.3 3.4 3.5 3.6 3.7 3.8 3.9 3.10 3.11 3.12 3.13 3.14 3.15 3.16 3.17

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