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(struct device *dev, int to)
  57 {
  58         unsigned int tmp;
  59
  60         dev_dbg(dev, "%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         dev_dbg(dev, "%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         dev_dbg(dev, "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         dev_dbg(dev, "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         dev_dbg(dev, "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         dev_dbg(dev, "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(dev, 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 const struct rtc_class_ops puv3_rtcops = {
 161         .read_time      = puv3_rtc_gettime,
 162         .set_time       = puv3_rtc_settime,
 163         .read_alarm     = puv3_rtc_getalarm,
 164         .set_alarm      = puv3_rtc_setalarm,
 165         .proc           = puv3_rtc_proc,
 166 };
 167
 168 static void puv3_rtc_enable(struct device *dev, int en)
 169 {
 170         if (!en) {
 171                 writel(readl(RTC_RTSR) & ~RTC_RTSR_HZE, RTC_RTSR);
 172         } else {
 173                 /* re-enable the device, and check it is ok */
 174                 if ((readl(RTC_RTSR) & RTC_RTSR_HZE) == 0) {
 175                         dev_info(dev, "rtc disabled, re-enabling\n");
 176                         writel(readl(RTC_RTSR) | RTC_RTSR_HZE, RTC_RTSR);
 177                 }
 178         }
 179 }
 180
 181 static int puv3_rtc_remove(struct platform_device *dev)
 182 {
 183         puv3_rtc_setpie(&dev->dev, 0);
 184         puv3_rtc_setaie(&dev->dev, 0);
 185
 186         release_resource(puv3_rtc_mem);
 187         kfree(puv3_rtc_mem);
 188
 189         return 0;
 190 }
 191
 192 static int puv3_rtc_probe(struct platform_device *pdev)
 193 {
 194         struct rtc_device *rtc;
 195         struct resource *res;
 196         int ret;
 197
 198         dev_dbg(&pdev->dev, "%s: probe=%p\n", __func__, pdev);
 199
 200         /* find the IRQs */
 201         puv3_rtc_tickno = platform_get_irq(pdev, 1);
 202         if (puv3_rtc_tickno < 0) {
 203                 dev_err(&pdev->dev, "no irq for rtc tick\n");
 204                 return -ENOENT;
 205         }
 206
 207         puv3_rtc_alarmno = platform_get_irq(pdev, 0);
 208         if (puv3_rtc_alarmno < 0) {
 209                 dev_err(&pdev->dev, "no irq for alarm\n");
 210                 return -ENOENT;
 211         }
 212
 213         dev_dbg(&pdev->dev, "PKUnity_rtc: tick irq %d, alarm irq %d\n",
 214                  puv3_rtc_tickno, puv3_rtc_alarmno);
 215
 216         rtc = devm_rtc_allocate_device(&pdev->dev);
 217         if (IS_ERR(rtc))
 218                 return PTR_ERR(rtc);
 219
 220         ret = devm_request_irq(&pdev->dev, puv3_rtc_alarmno, puv3_rtc_alarmirq,
 221                                0, "pkunity-rtc alarm", rtc);
 222         if (ret) {
 223                 dev_err(&pdev->dev, "IRQ%d error %d\n", puv3_rtc_alarmno, ret);
 224                 return ret;
 225         }
 226
 227         ret = devm_request_irq(&pdev->dev, puv3_rtc_tickno, puv3_rtc_tickirq,
 228                                0, "pkunity-rtc tick", rtc);
 229         if (ret) {
 230                 dev_err(&pdev->dev, "IRQ%d error %d\n", puv3_rtc_tickno, ret);
 231                 return ret;
 232         }
 233
 234         /* get the memory region */
 235         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 236         if (res == NULL) {
 237                 dev_err(&pdev->dev, "failed to get memory region resource\n");
 238                 return -ENOENT;
 239         }
 240
 241         puv3_rtc_mem = request_mem_region(res->start, resource_size(res),
 242                                           pdev->name);
 243
 244         if (puv3_rtc_mem == NULL) {
 245                 dev_err(&pdev->dev, "failed to reserve memory region\n");
 246                 ret = -ENOENT;
 247                 goto err_nores;
 248         }
 249
 250         puv3_rtc_enable(&pdev->dev, 1);
 251
 252         /* register RTC and exit */
 253         rtc->ops = &puv3_rtcops;
 254         ret = rtc_register_device(rtc);
 255         if (ret) {
 256                 dev_err(&pdev->dev, "cannot attach rtc\n");
 257                 goto err_nortc;
 258         }
 259
 260         /* platform setup code should have handled this; sigh */
 261         if (!device_can_wakeup(&pdev->dev))
 262                 device_init_wakeup(&pdev->dev, 1);
 263
 264         platform_set_drvdata(pdev, rtc);
 265         return 0;
 266
 267  err_nortc:
 268         puv3_rtc_enable(&pdev->dev, 0);
 269         release_resource(puv3_rtc_mem);
 270
 271  err_nores:
 272         return ret;
 273 }
 274
 275 #ifdef CONFIG_PM_SLEEP
 276 static int ticnt_save;
 277
 278 static int puv3_rtc_suspend(struct device *dev)
 279 {
 280         /* save RTAR for anyone using periodic interrupts */
 281         ticnt_save = readl(RTC_RTAR);
 282         puv3_rtc_enable(dev, 0);
 283         return 0;
 284 }
 285
 286 static int puv3_rtc_resume(struct device *dev)
 287 {
 288         puv3_rtc_enable(dev, 1);
 289         writel(ticnt_save, RTC_RTAR);
 290         return 0;
 291 }
 292 #endif
 293
 294 static SIMPLE_DEV_PM_OPS(puv3_rtc_pm_ops, puv3_rtc_suspend, puv3_rtc_resume);
 295
 296 static struct platform_driver puv3_rtc_driver = {
 297         .probe          = puv3_rtc_probe,
 298         .remove         = puv3_rtc_remove,
 299         .driver         = {
 300                 .name   = "PKUnity-v3-RTC",
 301                 .pm     = &puv3_rtc_pm_ops,
 302         }
 303 };
 304
 305 module_platform_driver(puv3_rtc_driver);
 306
 307 MODULE_DESCRIPTION("RTC Driver for the PKUnity v3 chip");
 308 MODULE_AUTHOR("Hu Dongliang");
 309 MODULE_LICENSE("GPL v2");