arch/unicore32/kernel/rtc.c

   1 /*
   2  * linux/arch/unicore32/kernel/rtc.c
   3  *
   4  * Code specific to PKUnity SoC and UniCore ISA
   5  *
   6  *      Maintained by GUAN Xue-tao <gxt@mprc.pku.edu.cn>
   7  *      Copyright (C) 2001-2010 Guan Xuetao
   8  *
   9  * This program is free software; you can redistribute it and/or modify
  10  * it under the terms of the GNU General Public License version 2 as
  11  * published by the Free Software Foundation.
  12  */
  13
  14 #include <linux/module.h>
  15 #include <linux/fs.h>
  16 #include <linux/string.h>
  17 #include <linux/init.h>
  18 #include <linux/platform_device.h>
  19 #include <linux/interrupt.h>
  20 #include <linux/rtc.h>
  21 #include <linux/bcd.h>
  22 #include <linux/clk.h>
  23 #include <linux/log2.h>
  24 #include <linux/slab.h>
  25 #include <linux/uaccess.h>
  26 #include <linux/io.h>
  27
  28 #include <asm/irq.h>
  29 #include <mach/hardware.h>
  30
  31 static struct resource *puv3_rtc_mem;
  32
  33 static int puv3_rtc_alarmno = IRQ_RTCAlarm;
  34 static int puv3_rtc_tickno  = IRQ_RTC;
  35
  36 static DEFINE_SPINLOCK(puv3_rtc_pie_lock);
  37
  38 /* IRQ Handlers */
  39
  40 static irqreturn_t puv3_rtc_alarmirq(int irq, void *id)
  41 {
  42         struct rtc_device *rdev = id;
  43
  44         writel(readl(RTC_RTSR) | RTC_RTSR_AL, RTC_RTSR);
  45         rtc_update_irq(rdev, 1, RTC_AF | RTC_IRQF);
  46         return IRQ_HANDLED;
  47 }
  48
  49 static irqreturn_t puv3_rtc_tickirq(int irq, void *id)
  50 {
  51         struct rtc_device *rdev = id;
  52
  53         writel(readl(RTC_RTSR) | RTC_RTSR_HZ, RTC_RTSR);
  54         rtc_update_irq(rdev, 1, RTC_PF | RTC_IRQF);
  55         return IRQ_HANDLED;
  56 }
  57
  58 /* Update control registers */
  59 static void puv3_rtc_setaie(int to)
  60 {
  61         unsigned int tmp;
  62
  63         pr_debug("%s: aie=%d\n", __func__, to);
  64
  65         tmp = readl(RTC_RTSR) & ~RTC_RTSR_ALE;
  66
  67         if (to)
  68                 tmp |= RTC_RTSR_ALE;
  69
  70         writel(tmp, RTC_RTSR);
  71 }
  72
  73 static int puv3_rtc_setpie(struct device *dev, int enabled)
  74 {
  75         unsigned int tmp;
  76
  77         pr_debug("%s: pie=%d\n", __func__, enabled);
  78
  79         spin_lock_irq(&puv3_rtc_pie_lock);
  80         tmp = readl(RTC_RTSR) & ~RTC_RTSR_HZE;
  81
  82         if (enabled)
  83                 tmp |= RTC_RTSR_HZE;
  84
  85         writel(tmp, RTC_RTSR);
  86         spin_unlock_irq(&puv3_rtc_pie_lock);
  87
  88         return 0;
  89 }
  90
  91 static int puv3_rtc_setfreq(struct device *dev, int freq)
  92 {
  93         return 0;
  94 }
  95
  96 /* Time read/write */
  97
  98 static int puv3_rtc_gettime(struct device *dev, struct rtc_time *rtc_tm)
  99 {
 100         rtc_time_to_tm(readl(RTC_RCNR), rtc_tm);
 101
 102         pr_debug("read time %02x.%02x.%02x %02x/%02x/%02x\n",
 103                  rtc_tm->tm_year, rtc_tm->tm_mon, rtc_tm->tm_mday,
 104                  rtc_tm->tm_hour, rtc_tm->tm_min, rtc_tm->tm_sec);
 105
 106         return 0;
 107 }
 108
 109 static int puv3_rtc_settime(struct device *dev, struct rtc_time *tm)
 110 {
 111         unsigned long rtc_count = 0;
 112
 113         pr_debug("set time %02d.%02d.%02d %02d/%02d/%02d\n",
 114                  tm->tm_year, tm->tm_mon, tm->tm_mday,
 115                  tm->tm_hour, tm->tm_min, tm->tm_sec);
 116
 117         rtc_tm_to_time(tm, &rtc_count);
 118         writel(rtc_count, RTC_RCNR);
 119
 120         return 0;
 121 }
 122
 123 static int puv3_rtc_getalarm(struct device *dev, struct rtc_wkalrm *alrm)
 124 {
 125         struct rtc_time *alm_tm = &alrm->time;
 126
 127         rtc_time_to_tm(readl(RTC_RTAR), alm_tm);
 128
 129         alrm->enabled = readl(RTC_RTSR) & RTC_RTSR_ALE;
 130
 131         pr_debug("read alarm %02x %02x.%02x.%02x %02x/%02x/%02x\n",
 132                  alrm->enabled,
 133                  alm_tm->tm_year, alm_tm->tm_mon, alm_tm->tm_mday,
 134                  alm_tm->tm_hour, alm_tm->tm_min, alm_tm->tm_sec);
 135
 136         return 0;
 137 }
 138
 139 static int puv3_rtc_setalarm(struct device *dev, struct rtc_wkalrm *alrm)
 140 {
 141         struct rtc_time *tm = &alrm->time;
 142         unsigned long rtcalarm_count = 0;
 143
 144         pr_debug("puv3_rtc_setalarm: %d, %02x/%02x/%02x %02x.%02x.%02x\n",
 145                  alrm->enabled,
 146                  tm->tm_mday & 0xff, tm->tm_mon & 0xff, tm->tm_year & 0xff,
 147                  tm->tm_hour & 0xff, tm->tm_min & 0xff, tm->tm_sec);
 148
 149         rtc_tm_to_time(tm, &rtcalarm_count);
 150         writel(rtcalarm_count, RTC_RTAR);
 151
 152         puv3_rtc_setaie(alrm->enabled);
 153
 154         if (alrm->enabled)
 155                 enable_irq_wake(puv3_rtc_alarmno);
 156         else
 157                 disable_irq_wake(puv3_rtc_alarmno);
 158
 159         return 0;
 160 }
 161
 162 static int puv3_rtc_proc(struct device *dev, struct seq_file *seq)
 163 {
 164         seq_printf(seq, "periodic_IRQ\t: %s\n",
 165                      (readl(RTC_RTSR) & RTC_RTSR_HZE) ? "yes" : "no");
 166         return 0;
 167 }
 168
 169 static int puv3_rtc_open(struct device *dev)
 170 {
 171         struct platform_device *pdev = to_platform_device(dev);
 172         struct rtc_device *rtc_dev = platform_get_drvdata(pdev);
 173         int ret;
 174
 175         ret = request_irq(puv3_rtc_alarmno, puv3_rtc_alarmirq,
 176                           IRQF_DISABLED,  "pkunity-rtc alarm", rtc_dev);
 177
 178         if (ret) {
 179                 dev_err(dev, "IRQ%d error %d\n", puv3_rtc_alarmno, ret);
 180                 return ret;
 181         }
 182
 183         ret = request_irq(puv3_rtc_tickno, puv3_rtc_tickirq,
 184                           IRQF_DISABLED,  "pkunity-rtc tick", rtc_dev);
 185
 186         if (ret) {
 187                 dev_err(dev, "IRQ%d error %d\n", puv3_rtc_tickno, ret);
 188                 goto tick_err;
 189         }
 190
 191         return ret;
 192
 193  tick_err:
 194         free_irq(puv3_rtc_alarmno, rtc_dev);
 195         return ret;
 196 }
 197
 198 static void puv3_rtc_release(struct device *dev)
 199 {
 200         struct platform_device *pdev = to_platform_device(dev);
 201         struct rtc_device *rtc_dev = platform_get_drvdata(pdev);
 202
 203         /* do not clear AIE here, it may be needed for wake */
 204
 205         puv3_rtc_setpie(dev, 0);
 206         free_irq(puv3_rtc_alarmno, rtc_dev);
 207         free_irq(puv3_rtc_tickno, rtc_dev);
 208 }
 209
 210 static const struct rtc_class_ops puv3_rtcops = {
 211         .open           = puv3_rtc_open,
 212         .release        = puv3_rtc_release,
 213         .read_time      = puv3_rtc_gettime,
 214         .set_time       = puv3_rtc_settime,
 215         .read_alarm     = puv3_rtc_getalarm,
 216         .set_alarm      = puv3_rtc_setalarm,
 217         .irq_set_freq   = puv3_rtc_setfreq,
 218         .irq_set_state  = puv3_rtc_setpie,
 219         .proc           = puv3_rtc_proc,
 220 };
 221
 222 static void puv3_rtc_enable(struct platform_device *pdev, int en)
 223 {
 224         if (!en) {
 225                 writel(readl(RTC_RTSR) & ~RTC_RTSR_HZE, RTC_RTSR);
 226         } else {
 227                 /* re-enable the device, and check it is ok */
 228
 229                 if ((readl(RTC_RTSR) & RTC_RTSR_HZE) == 0) {
 230                         dev_info(&pdev->dev, "rtc disabled, re-enabling\n");
 231                         writel(readl(RTC_RTSR) | RTC_RTSR_HZE, RTC_RTSR);
 232                 }
 233         }
 234 }
 235
 236 static int puv3_rtc_remove(struct platform_device *dev)
 237 {
 238         struct rtc_device *rtc = platform_get_drvdata(dev);
 239
 240         platform_set_drvdata(dev, NULL);
 241         rtc_device_unregister(rtc);
 242
 243         puv3_rtc_setpie(&dev->dev, 0);
 244         puv3_rtc_setaie(0);
 245
 246         release_resource(puv3_rtc_mem);
 247         kfree(puv3_rtc_mem);
 248
 249         return 0;
 250 }
 251
 252 static int puv3_rtc_probe(struct platform_device *pdev)
 253 {
 254         struct rtc_device *rtc;
 255         struct resource *res;
 256         int ret;
 257
 258         pr_debug("%s: probe=%p\n", __func__, pdev);
 259
 260         /* find the IRQs */
 261
 262         puv3_rtc_tickno = platform_get_irq(pdev, 1);
 263         if (puv3_rtc_tickno < 0) {
 264                 dev_err(&pdev->dev, "no irq for rtc tick\n");
 265                 return -ENOENT;
 266         }
 267
 268         puv3_rtc_alarmno = platform_get_irq(pdev, 0);
 269         if (puv3_rtc_alarmno < 0) {
 270                 dev_err(&pdev->dev, "no irq for alarm\n");
 271                 return -ENOENT;
 272         }
 273
 274         pr_debug("PKUnity_rtc: tick irq %d, alarm irq %d\n",
 275                  puv3_rtc_tickno, puv3_rtc_alarmno);
 276
 277         /* get the memory region */
 278
 279         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 280         if (res == NULL) {
 281                 dev_err(&pdev->dev, "failed to get memory region resource\n");
 282                 return -ENOENT;
 283         }
 284
 285         puv3_rtc_mem = request_mem_region(res->start,
 286                                          res->end-res->start+1,
 287                                          pdev->name);
 288
 289         if (puv3_rtc_mem == NULL) {
 290                 dev_err(&pdev->dev, "failed to reserve memory region\n");
 291                 ret = -ENOENT;
 292                 goto err_nores;
 293         }
 294
 295         puv3_rtc_enable(pdev, 1);
 296
 297         puv3_rtc_setfreq(&pdev->dev, 1);
 298
 299         /* register RTC and exit */
 300
 301         rtc = rtc_device_register("pkunity", &pdev->dev, &puv3_rtcops,
 302                                   THIS_MODULE);
 303
 304         if (IS_ERR(rtc)) {
 305                 dev_err(&pdev->dev, "cannot attach rtc\n");
 306                 ret = PTR_ERR(rtc);
 307                 goto err_nortc;
 308         }
 309
 310         /* platform setup code should have handled this; sigh */
 311         if (!device_can_wakeup(&pdev->dev))
 312                 device_init_wakeup(&pdev->dev, 1);
 313
 314         platform_set_drvdata(pdev, rtc);
 315         return 0;
 316
 317  err_nortc:
 318         puv3_rtc_enable(pdev, 0);
 319         release_resource(puv3_rtc_mem);
 320
 321  err_nores:
 322         return ret;
 323 }
 324
 325 #ifdef CONFIG_PM
 326
 327 /* RTC Power management control */
 328
 329 static int ticnt_save;
 330
 331 static int puv3_rtc_suspend(struct platform_device *pdev, pm_message_t state)
 332 {
 333         /* save RTAR for anyone using periodic interrupts */
 334         ticnt_save = readl(RTC_RTAR);
 335         puv3_rtc_enable(pdev, 0);
 336         return 0;
 337 }
 338
 339 static int puv3_rtc_resume(struct platform_device *pdev)
 340 {
 341         puv3_rtc_enable(pdev, 1);
 342         writel(ticnt_save, RTC_RTAR);
 343         return 0;
 344 }
 345 #else
 346 #define puv3_rtc_suspend NULL
 347 #define puv3_rtc_resume  NULL
 348 #endif
 349
 350 static struct platform_driver puv3_rtcdrv = {
 351         .probe          = puv3_rtc_probe,
 352         .remove         = __devexit_p(puv3_rtc_remove),
 353         .suspend        = puv3_rtc_suspend,
 354         .resume         = puv3_rtc_resume,
 355         .driver         = {
 356                 .name   = "PKUnity-v3-RTC",
 357                 .owner  = THIS_MODULE,
 358         }
 359 };
 360
 361 static char __initdata banner[] = "PKUnity-v3 RTC, (c) 2009 PKUnity Co.\n";
 362
 363 static int __init puv3_rtc_init(void)
 364 {
 365         printk(banner);
 366         return platform_driver_register(&puv3_rtcdrv);
 367 }
 368
 369 static void __exit puv3_rtc_exit(void)
 370 {
 371         platform_driver_unregister(&puv3_rtcdrv);
 372 }
 373
 374 module_init(puv3_rtc_init);
 375 module_exit(puv3_rtc_exit);
 376
 377 MODULE_DESCRIPTION("RTC Driver for the PKUnity v3 chip");
 378 MODULE_AUTHOR("Hu Dongliang");
 379 MODULE_LICENSE("GPL v2");
 380