drivers/rtc/rtc-puv3.c

   1 /*
   2  * RTC driver code specific to PKUnity SoC and UniCore ISA
   3  *
   4  *      Maintained by GUAN Xue-tao <gxt@mprc.pku.edu.cn>
   5  *      Copyright (C) 2001-2010 Guan Xuetao
   6  *
   7  * This program is free software; you can redistribute it and/or modify
   8  * it under the terms of the GNU General Public License version 2 as
   9  * published by the Free Software Foundation.
  10  */
  11
  12 #include <linux/module.h>
  13 #include <linux/fs.h>
  14 #include <linux/string.h>
  15 #include <linux/init.h>
  16 #include <linux/platform_device.h>
  17 #include <linux/interrupt.h>
  18 #include <linux/rtc.h>
  19 #include <linux/bcd.h>
  20 #include <linux/clk.h>
  21 #include <linux/log2.h>
  22 #include <linux/slab.h>
  23 #include <linux/uaccess.h>
  24 #include <linux/io.h>
  25
  26 #include <asm/irq.h>
  27 #include <mach/hardware.h>
  28
  29 static struct resource *puv3_rtc_mem;
  30
  31 static int puv3_rtc_alarmno = IRQ_RTCAlarm;
  32 static int puv3_rtc_tickno  = IRQ_RTC;
  33
  34 static DEFINE_SPINLOCK(puv3_rtc_pie_lock);
  35
  36 /* IRQ Handlers */
  37 static irqreturn_t puv3_rtc_alarmirq(int irq, void *id)
  38 {
  39         struct rtc_device *rdev = id;
  40
  41         writel(readl(RTC_RTSR) | RTC_RTSR_AL, RTC_RTSR);
  42         rtc_update_irq(rdev, 1, RTC_AF | RTC_IRQF);
  43         return IRQ_HANDLED;
  44 }
  45
  46 static irqreturn_t puv3_rtc_tickirq(int irq, void *id)
  47 {
  48         struct rtc_device *rdev = id;
  49
  50         writel(readl(RTC_RTSR) | RTC_RTSR_HZ, RTC_RTSR);
  51         rtc_update_irq(rdev, 1, RTC_PF | RTC_IRQF);
  52         return IRQ_HANDLED;
  53 }
  54
  55 /* Update control registers */
  56 static void puv3_rtc_setaie(int to)
  57 {
  58         unsigned int tmp;
  59
  60         pr_debug("%s: aie=%d\n", __func__, to);
  61
  62         tmp = readl(RTC_RTSR) & ~RTC_RTSR_ALE;
  63
  64         if (to)
  65                 tmp |= RTC_RTSR_ALE;
  66
  67         writel(tmp, RTC_RTSR);
  68 }
  69
  70 static int puv3_rtc_setpie(struct device *dev, int enabled)
  71 {
  72         unsigned int tmp;
  73
  74         pr_debug("%s: pie=%d\n", __func__, enabled);
  75
  76         spin_lock_irq(&puv3_rtc_pie_lock);
  77         tmp = readl(RTC_RTSR) & ~RTC_RTSR_HZE;
  78
  79         if (enabled)
  80                 tmp |= RTC_RTSR_HZE;
  81
  82         writel(tmp, RTC_RTSR);
  83         spin_unlock_irq(&puv3_rtc_pie_lock);
  84
  85         return 0;
  86 }
  87
  88 /* Time read/write */
  89 static int puv3_rtc_gettime(struct device *dev, struct rtc_time *rtc_tm)
  90 {
  91         rtc_time_to_tm(readl(RTC_RCNR), rtc_tm);
  92
  93         pr_debug("read time %02x.%02x.%02x %02x/%02x/%02x\n",
  94                  rtc_tm->tm_year, rtc_tm->tm_mon, rtc_tm->tm_mday,
  95                  rtc_tm->tm_hour, rtc_tm->tm_min, rtc_tm->tm_sec);
  96
  97         return 0;
  98 }
  99
 100 static int puv3_rtc_settime(struct device *dev, struct rtc_time *tm)
 101 {
 102         unsigned long rtc_count = 0;
 103
 104         pr_debug("set time %02d.%02d.%02d %02d/%02d/%02d\n",
 105                  tm->tm_year, tm->tm_mon, tm->tm_mday,
 106                  tm->tm_hour, tm->tm_min, tm->tm_sec);
 107
 108         rtc_tm_to_time(tm, &rtc_count);
 109         writel(rtc_count, RTC_RCNR);
 110
 111         return 0;
 112 }
 113
 114 static int puv3_rtc_getalarm(struct device *dev, struct rtc_wkalrm *alrm)
 115 {
 116         struct rtc_time *alm_tm = &alrm->time;
 117
 118         rtc_time_to_tm(readl(RTC_RTAR), alm_tm);
 119
 120         alrm->enabled = readl(RTC_RTSR) & RTC_RTSR_ALE;
 121
 122         pr_debug("read alarm %02x %02x.%02x.%02x %02x/%02x/%02x\n",
 123                  alrm->enabled,
 124                  alm_tm->tm_year, alm_tm->tm_mon, alm_tm->tm_mday,
 125                  alm_tm->tm_hour, alm_tm->tm_min, alm_tm->tm_sec);
 126
 127         return 0;
 128 }
 129
 130 static int puv3_rtc_setalarm(struct device *dev, struct rtc_wkalrm *alrm)
 131 {
 132         struct rtc_time *tm = &alrm->time;
 133         unsigned long rtcalarm_count = 0;
 134
 135         pr_debug("puv3_rtc_setalarm: %d, %02x/%02x/%02x %02x.%02x.%02x\n",
 136                  alrm->enabled,
 137                  tm->tm_mday & 0xff, tm->tm_mon & 0xff, tm->tm_year & 0xff,
 138                  tm->tm_hour & 0xff, tm->tm_min & 0xff, tm->tm_sec);
 139
 140         rtc_tm_to_time(tm, &rtcalarm_count);
 141         writel(rtcalarm_count, RTC_RTAR);
 142
 143         puv3_rtc_setaie(alrm->enabled);
 144
 145         if (alrm->enabled)
 146                 enable_irq_wake(puv3_rtc_alarmno);
 147         else
 148                 disable_irq_wake(puv3_rtc_alarmno);
 149
 150         return 0;
 151 }
 152
 153 static int puv3_rtc_proc(struct device *dev, struct seq_file *seq)
 154 {
 155         seq_printf(seq, "periodic_IRQ\t: %s\n",
 156                      (readl(RTC_RTSR) & RTC_RTSR_HZE) ? "yes" : "no");
 157         return 0;
 158 }
 159
 160 static int puv3_rtc_open(struct device *dev)
 161 {
 162         struct platform_device *pdev = to_platform_device(dev);
 163         struct rtc_device *rtc_dev = platform_get_drvdata(pdev);
 164         int ret;
 165
 166         ret = request_irq(puv3_rtc_alarmno, puv3_rtc_alarmirq,
 167                         0, "pkunity-rtc alarm", rtc_dev);
 168
 169         if (ret) {
 170                 dev_err(dev, "IRQ%d error %d\n", puv3_rtc_alarmno, ret);
 171                 return ret;
 172         }
 173
 174         ret = request_irq(puv3_rtc_tickno, puv3_rtc_tickirq,
 175                         0, "pkunity-rtc tick", rtc_dev);
 176
 177         if (ret) {
 178                 dev_err(dev, "IRQ%d error %d\n", puv3_rtc_tickno, ret);
 179                 goto tick_err;
 180         }
 181
 182         return ret;
 183
 184  tick_err:
 185         free_irq(puv3_rtc_alarmno, rtc_dev);
 186         return ret;
 187 }
 188
 189 static void puv3_rtc_release(struct device *dev)
 190 {
 191         struct platform_device *pdev = to_platform_device(dev);
 192         struct rtc_device *rtc_dev = platform_get_drvdata(pdev);
 193
 194         /* do not clear AIE here, it may be needed for wake */
 195         puv3_rtc_setpie(dev, 0);
 196         free_irq(puv3_rtc_alarmno, rtc_dev);
 197         free_irq(puv3_rtc_tickno, rtc_dev);
 198 }
 199
 200 static const struct rtc_class_ops puv3_rtcops = {
 201         .open           = puv3_rtc_open,
 202         .release        = puv3_rtc_release,
 203         .read_time      = puv3_rtc_gettime,
 204         .set_time       = puv3_rtc_settime,
 205         .read_alarm     = puv3_rtc_getalarm,
 206         .set_alarm      = puv3_rtc_setalarm,
 207         .proc           = puv3_rtc_proc,
 208 };
 209
 210 static void puv3_rtc_enable(struct platform_device *pdev, int en)
 211 {
 212         if (!en) {
 213                 writel(readl(RTC_RTSR) & ~RTC_RTSR_HZE, RTC_RTSR);
 214         } else {
 215                 /* re-enable the device, and check it is ok */
 216                 if ((readl(RTC_RTSR) & RTC_RTSR_HZE) == 0) {
 217                         dev_info(&pdev->dev, "rtc disabled, re-enabling\n");
 218                         writel(readl(RTC_RTSR) | RTC_RTSR_HZE, RTC_RTSR);
 219                 }
 220         }
 221 }
 222
 223 static int puv3_rtc_remove(struct platform_device *dev)
 224 {
 225         struct rtc_device *rtc = platform_get_drvdata(dev);
 226
 227         platform_set_drvdata(dev, NULL);
 228         rtc_device_unregister(rtc);
 229
 230         puv3_rtc_setpie(&dev->dev, 0);
 231         puv3_rtc_setaie(0);
 232
 233         release_resource(puv3_rtc_mem);
 234         kfree(puv3_rtc_mem);
 235
 236         return 0;
 237 }
 238
 239 static int puv3_rtc_probe(struct platform_device *pdev)
 240 {
 241         struct rtc_device *rtc;
 242         struct resource *res;
 243         int ret;
 244
 245         pr_debug("%s: probe=%p\n", __func__, pdev);
 246
 247         /* find the IRQs */
 248         puv3_rtc_tickno = platform_get_irq(pdev, 1);
 249         if (puv3_rtc_tickno < 0) {
 250                 dev_err(&pdev->dev, "no irq for rtc tick\n");
 251                 return -ENOENT;
 252         }
 253
 254         puv3_rtc_alarmno = platform_get_irq(pdev, 0);
 255         if (puv3_rtc_alarmno < 0) {
 256                 dev_err(&pdev->dev, "no irq for alarm\n");
 257                 return -ENOENT;
 258         }
 259
 260         pr_debug("PKUnity_rtc: tick irq %d, alarm irq %d\n",
 261                  puv3_rtc_tickno, puv3_rtc_alarmno);
 262
 263         /* get the memory region */
 264         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 265         if (res == NULL) {
 266                 dev_err(&pdev->dev, "failed to get memory region resource\n");
 267                 return -ENOENT;
 268         }
 269
 270         puv3_rtc_mem = request_mem_region(res->start, resource_size(res),
 271                                           pdev->name);
 272
 273         if (puv3_rtc_mem == NULL) {
 274                 dev_err(&pdev->dev, "failed to reserve memory region\n");
 275                 ret = -ENOENT;
 276                 goto err_nores;
 277         }
 278
 279         puv3_rtc_enable(pdev, 1);
 280
 281         /* register RTC and exit */
 282         rtc = rtc_device_register("pkunity", &pdev->dev, &puv3_rtcops,
 283                                   THIS_MODULE);
 284
 285         if (IS_ERR(rtc)) {
 286                 dev_err(&pdev->dev, "cannot attach rtc\n");
 287                 ret = PTR_ERR(rtc);
 288                 goto err_nortc;
 289         }
 290
 291         /* platform setup code should have handled this; sigh */
 292         if (!device_can_wakeup(&pdev->dev))
 293                 device_init_wakeup(&pdev->dev, 1);
 294
 295         platform_set_drvdata(pdev, rtc);
 296         return 0;
 297
 298  err_nortc:
 299         puv3_rtc_enable(pdev, 0);
 300         release_resource(puv3_rtc_mem);
 301
 302  err_nores:
 303         return ret;
 304 }
 305
 306 #ifdef CONFIG_PM
 307
 308 static int ticnt_save;
 309
 310 static int puv3_rtc_suspend(struct platform_device *pdev, pm_message_t state)
 311 {
 312         /* save RTAR for anyone using periodic interrupts */
 313         ticnt_save = readl(RTC_RTAR);
 314         puv3_rtc_enable(pdev, 0);
 315         return 0;
 316 }
 317
 318 static int puv3_rtc_resume(struct platform_device *pdev)
 319 {
 320         puv3_rtc_enable(pdev, 1);
 321         writel(ticnt_save, RTC_RTAR);
 322         return 0;
 323 }
 324 #else
 325 #define puv3_rtc_suspend NULL
 326 #define puv3_rtc_resume  NULL
 327 #endif
 328
 329 static struct platform_driver puv3_rtc_driver = {
 330         .probe          = puv3_rtc_probe,
 331         .remove         = puv3_rtc_remove,
 332         .suspend        = puv3_rtc_suspend,
 333         .resume         = puv3_rtc_resume,
 334         .driver         = {
 335                 .name   = "PKUnity-v3-RTC",
 336                 .owner  = THIS_MODULE,
 337         }
 338 };
 339
 340 module_platform_driver(puv3_rtc_driver);
 341
 342 MODULE_DESCRIPTION("RTC Driver for the PKUnity v3 chip");
 343 MODULE_AUTHOR("Hu Dongliang");
 344 MODULE_LICENSE("GPL v2");