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 /* Time read/write */
  92
  93 static int puv3_rtc_gettime(struct device *dev, struct rtc_time *rtc_tm)
  94 {
  95         rtc_time_to_tm(readl(RTC_RCNR), rtc_tm);
  96
  97         pr_debug("read time %02x.%02x.%02x %02x/%02x/%02x\n",
  98                  rtc_tm->tm_year, rtc_tm->tm_mon, rtc_tm->tm_mday,
  99                  rtc_tm->tm_hour, rtc_tm->tm_min, rtc_tm->tm_sec);
 100
 101         return 0;
 102 }
 103
 104 static int puv3_rtc_settime(struct device *dev, struct rtc_time *tm)
 105 {
 106         unsigned long rtc_count = 0;
 107
 108         pr_debug("set time %02d.%02d.%02d %02d/%02d/%02d\n",
 109                  tm->tm_year, tm->tm_mon, tm->tm_mday,
 110                  tm->tm_hour, tm->tm_min, tm->tm_sec);
 111
 112         rtc_tm_to_time(tm, &rtc_count);
 113         writel(rtc_count, RTC_RCNR);
 114
 115         return 0;
 116 }
 117
 118 static int puv3_rtc_getalarm(struct device *dev, struct rtc_wkalrm *alrm)
 119 {
 120         struct rtc_time *alm_tm = &alrm->time;
 121
 122         rtc_time_to_tm(readl(RTC_RTAR), alm_tm);
 123
 124         alrm->enabled = readl(RTC_RTSR) & RTC_RTSR_ALE;
 125
 126         pr_debug("read alarm %02x %02x.%02x.%02x %02x/%02x/%02x\n",
 127                  alrm->enabled,
 128                  alm_tm->tm_year, alm_tm->tm_mon, alm_tm->tm_mday,
 129                  alm_tm->tm_hour, alm_tm->tm_min, alm_tm->tm_sec);
 130
 131         return 0;
 132 }
 133
 134 static int puv3_rtc_setalarm(struct device *dev, struct rtc_wkalrm *alrm)
 135 {
 136         struct rtc_time *tm = &alrm->time;
 137         unsigned long rtcalarm_count = 0;
 138
 139         pr_debug("puv3_rtc_setalarm: %d, %02x/%02x/%02x %02x.%02x.%02x\n",
 140                  alrm->enabled,
 141                  tm->tm_mday & 0xff, tm->tm_mon & 0xff, tm->tm_year & 0xff,
 142                  tm->tm_hour & 0xff, tm->tm_min & 0xff, tm->tm_sec);
 143
 144         rtc_tm_to_time(tm, &rtcalarm_count);
 145         writel(rtcalarm_count, RTC_RTAR);
 146
 147         puv3_rtc_setaie(alrm->enabled);
 148
 149         if (alrm->enabled)
 150                 enable_irq_wake(puv3_rtc_alarmno);
 151         else
 152                 disable_irq_wake(puv3_rtc_alarmno);
 153
 154         return 0;
 155 }
 156
 157 static int puv3_rtc_proc(struct device *dev, struct seq_file *seq)
 158 {
 159         seq_printf(seq, "periodic_IRQ\t: %s\n",
 160                      (readl(RTC_RTSR) & RTC_RTSR_HZE) ? "yes" : "no");
 161         return 0;
 162 }
 163
 164 static int puv3_rtc_open(struct device *dev)
 165 {
 166         struct platform_device *pdev = to_platform_device(dev);
 167         struct rtc_device *rtc_dev = platform_get_drvdata(pdev);
 168         int ret;
 169
 170         ret = request_irq(puv3_rtc_alarmno, puv3_rtc_alarmirq,
 171                           IRQF_DISABLED,  "pkunity-rtc alarm", rtc_dev);
 172
 173         if (ret) {
 174                 dev_err(dev, "IRQ%d error %d\n", puv3_rtc_alarmno, ret);
 175                 return ret;
 176         }
 177
 178         ret = request_irq(puv3_rtc_tickno, puv3_rtc_tickirq,
 179                           IRQF_DISABLED,  "pkunity-rtc tick", rtc_dev);
 180
 181         if (ret) {
 182                 dev_err(dev, "IRQ%d error %d\n", puv3_rtc_tickno, ret);
 183                 goto tick_err;
 184         }
 185
 186         return ret;
 187
 188  tick_err:
 189         free_irq(puv3_rtc_alarmno, rtc_dev);
 190         return ret;
 191 }
 192
 193 static void puv3_rtc_release(struct device *dev)
 194 {
 195         struct platform_device *pdev = to_platform_device(dev);
 196         struct rtc_device *rtc_dev = platform_get_drvdata(pdev);
 197
 198         /* do not clear AIE here, it may be needed for wake */
 199
 200         puv3_rtc_setpie(dev, 0);
 201         free_irq(puv3_rtc_alarmno, rtc_dev);
 202         free_irq(puv3_rtc_tickno, rtc_dev);
 203 }
 204
 205 static const struct rtc_class_ops puv3_rtcops = {
 206         .open           = puv3_rtc_open,
 207         .release        = puv3_rtc_release,
 208         .read_time      = puv3_rtc_gettime,
 209         .set_time       = puv3_rtc_settime,
 210         .read_alarm     = puv3_rtc_getalarm,
 211         .set_alarm      = puv3_rtc_setalarm,
 212         .proc           = puv3_rtc_proc,
 213 };
 214
 215 static void puv3_rtc_enable(struct platform_device *pdev, int en)
 216 {
 217         if (!en) {
 218                 writel(readl(RTC_RTSR) & ~RTC_RTSR_HZE, RTC_RTSR);
 219         } else {
 220                 /* re-enable the device, and check it is ok */
 221
 222                 if ((readl(RTC_RTSR) & RTC_RTSR_HZE) == 0) {
 223                         dev_info(&pdev->dev, "rtc disabled, re-enabling\n");
 224                         writel(readl(RTC_RTSR) | RTC_RTSR_HZE, RTC_RTSR);
 225                 }
 226         }
 227 }
 228
 229 static int puv3_rtc_remove(struct platform_device *dev)
 230 {
 231         struct rtc_device *rtc = platform_get_drvdata(dev);
 232
 233         platform_set_drvdata(dev, NULL);
 234         rtc_device_unregister(rtc);
 235
 236         puv3_rtc_setpie(&dev->dev, 0);
 237         puv3_rtc_setaie(0);
 238
 239         release_resource(puv3_rtc_mem);
 240         kfree(puv3_rtc_mem);
 241
 242         return 0;
 243 }
 244
 245 static int puv3_rtc_probe(struct platform_device *pdev)
 246 {
 247         struct rtc_device *rtc;
 248         struct resource *res;
 249         int ret;
 250
 251         pr_debug("%s: probe=%p\n", __func__, pdev);
 252
 253         /* find the IRQs */
 254
 255         puv3_rtc_tickno = platform_get_irq(pdev, 1);
 256         if (puv3_rtc_tickno < 0) {
 257                 dev_err(&pdev->dev, "no irq for rtc tick\n");
 258                 return -ENOENT;
 259         }
 260
 261         puv3_rtc_alarmno = platform_get_irq(pdev, 0);
 262         if (puv3_rtc_alarmno < 0) {
 263                 dev_err(&pdev->dev, "no irq for alarm\n");
 264                 return -ENOENT;
 265         }
 266
 267         pr_debug("PKUnity_rtc: tick irq %d, alarm irq %d\n",
 268                  puv3_rtc_tickno, puv3_rtc_alarmno);
 269
 270         /* get the memory region */
 271
 272         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 273         if (res == NULL) {
 274                 dev_err(&pdev->dev, "failed to get memory region resource\n");
 275                 return -ENOENT;
 276         }
 277
 278         puv3_rtc_mem = request_mem_region(res->start,
 279                                          res->end-res->start+1,
 280                                          pdev->name);
 281
 282         if (puv3_rtc_mem == NULL) {
 283                 dev_err(&pdev->dev, "failed to reserve memory region\n");
 284                 ret = -ENOENT;
 285                 goto err_nores;
 286         }
 287
 288         puv3_rtc_enable(pdev, 1);
 289
 290         /* register RTC and exit */
 291
 292         rtc = rtc_device_register("pkunity", &pdev->dev, &puv3_rtcops,
 293                                   THIS_MODULE);
 294
 295         if (IS_ERR(rtc)) {
 296                 dev_err(&pdev->dev, "cannot attach rtc\n");
 297                 ret = PTR_ERR(rtc);
 298                 goto err_nortc;
 299         }
 300
 301         /* platform setup code should have handled this; sigh */
 302         if (!device_can_wakeup(&pdev->dev))
 303                 device_init_wakeup(&pdev->dev, 1);
 304
 305         platform_set_drvdata(pdev, rtc);
 306         return 0;
 307
 308  err_nortc:
 309         puv3_rtc_enable(pdev, 0);
 310         release_resource(puv3_rtc_mem);
 311
 312  err_nores:
 313         return ret;
 314 }
 315
 316 #ifdef CONFIG_PM
 317
 318 /* RTC Power management control */
 319
 320 static int ticnt_save;
 321
 322 static int puv3_rtc_suspend(struct platform_device *pdev, pm_message_t state)
 323 {
 324         /* save RTAR for anyone using periodic interrupts */
 325         ticnt_save = readl(RTC_RTAR);
 326         puv3_rtc_enable(pdev, 0);
 327         return 0;
 328 }
 329
 330 static int puv3_rtc_resume(struct platform_device *pdev)
 331 {
 332         puv3_rtc_enable(pdev, 1);
 333         writel(ticnt_save, RTC_RTAR);
 334         return 0;
 335 }
 336 #else
 337 #define puv3_rtc_suspend NULL
 338 #define puv3_rtc_resume  NULL
 339 #endif
 340
 341 static struct platform_driver puv3_rtcdrv = {
 342         .probe          = puv3_rtc_probe,
 343         .remove         = __devexit_p(puv3_rtc_remove),
 344         .suspend        = puv3_rtc_suspend,
 345         .resume         = puv3_rtc_resume,
 346         .driver         = {
 347                 .name   = "PKUnity-v3-RTC",
 348                 .owner  = THIS_MODULE,
 349         }
 350 };
 351
 352 static char __initdata banner[] = "PKUnity-v3 RTC, (c) 2009 PKUnity Co.\n";
 353
 354 static int __init puv3_rtc_init(void)
 355 {
 356         printk(banner);
 357         return platform_driver_register(&puv3_rtcdrv);
 358 }
 359
 360 static void __exit puv3_rtc_exit(void)
 361 {
 362         platform_driver_unregister(&puv3_rtcdrv);
 363 }
 364
 365 module_init(puv3_rtc_init);
 366 module_exit(puv3_rtc_exit);
 367
 368 MODULE_DESCRIPTION("RTC Driver for the PKUnity v3 chip");
 369 MODULE_AUTHOR("Hu Dongliang");
 370 MODULE_LICENSE("GPL v2");
 371