drivers/rtc/rtc-mv.c

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