kernel/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 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 device *dev, 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(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         rtc_device_unregister(rtc);
 228
 229         puv3_rtc_setpie(&dev->dev, 0);
 230         puv3_rtc_setaie(&dev->dev, 0);
 231
 232         release_resource(puv3_rtc_mem);
 233         kfree(puv3_rtc_mem);
 234
 235         return 0;
 236 }
 237
 238 static int puv3_rtc_probe(struct platform_device *pdev)
 239 {
 240         struct rtc_device *rtc;
 241         struct resource *res;
 242         int ret;
 243
 244         dev_dbg(&pdev->dev, "%s: probe=%p\n", __func__, pdev);
 245
 246         /* find the IRQs */
 247         puv3_rtc_tickno = platform_get_irq(pdev, 1);
 248         if (puv3_rtc_tickno < 0) {
 249                 dev_err(&pdev->dev, "no irq for rtc tick\n");
 250                 return -ENOENT;
 251         }
 252
 253         puv3_rtc_alarmno = platform_get_irq(pdev, 0);
 254         if (puv3_rtc_alarmno < 0) {
 255                 dev_err(&pdev->dev, "no irq for alarm\n");
 256                 return -ENOENT;
 257         }
 258
 259         dev_dbg(&pdev->dev, "PKUnity_rtc: tick irq %d, alarm irq %d\n",
 260                  puv3_rtc_tickno, puv3_rtc_alarmno);
 261
 262         /* get the memory region */
 263         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 264         if (res == NULL) {
 265                 dev_err(&pdev->dev, "failed to get memory region resource\n");
 266                 return -ENOENT;
 267         }
 268
 269         puv3_rtc_mem = request_mem_region(res->start, resource_size(res),
 270                                           pdev->name);
 271
 272         if (puv3_rtc_mem == NULL) {
 273                 dev_err(&pdev->dev, "failed to reserve memory region\n");
 274                 ret = -ENOENT;
 275                 goto err_nores;
 276         }
 277
 278         puv3_rtc_enable(&pdev->dev, 1);
 279
 280         /* register RTC and exit */
 281         rtc = rtc_device_register("pkunity", &pdev->dev, &puv3_rtcops,
 282                                   THIS_MODULE);
 283
 284         if (IS_ERR(rtc)) {
 285                 dev_err(&pdev->dev, "cannot attach rtc\n");
 286                 ret = PTR_ERR(rtc);
 287                 goto err_nortc;
 288         }
 289
 290         /* platform setup code should have handled this; sigh */
 291         if (!device_can_wakeup(&pdev->dev))
 292                 device_init_wakeup(&pdev->dev, 1);
 293
 294         platform_set_drvdata(pdev, rtc);
 295         return 0;
 296
 297  err_nortc:
 298         puv3_rtc_enable(&pdev->dev, 0);
 299         release_resource(puv3_rtc_mem);
 300
 301  err_nores:
 302         return ret;
 303 }
 304
 305 #ifdef CONFIG_PM_SLEEP
 306 static int ticnt_save;
 307
 308 static int puv3_rtc_suspend(struct device *dev)
 309 {
 310         /* save RTAR for anyone using periodic interrupts */
 311         ticnt_save = readl(RTC_RTAR);
 312         puv3_rtc_enable(dev, 0);
 313         return 0;
 314 }
 315
 316 static int puv3_rtc_resume(struct device *dev)
 317 {
 318         puv3_rtc_enable(dev, 1);
 319         writel(ticnt_save, RTC_RTAR);
 320         return 0;
 321 }
 322 #endif
 323
 324 static SIMPLE_DEV_PM_OPS(puv3_rtc_pm_ops, puv3_rtc_suspend, puv3_rtc_resume);
 325
 326 static struct platform_driver puv3_rtc_driver = {
 327         .probe          = puv3_rtc_probe,
 328         .remove         = puv3_rtc_remove,
 329         .driver         = {
 330                 .name   = "PKUnity-v3-RTC",
 331                 .pm     = &puv3_rtc_pm_ops,
 332         }
 333 };
 334
 335 module_platform_driver(puv3_rtc_driver);
 336
 337 MODULE_DESCRIPTION("RTC Driver for the PKUnity v3 chip");
 338 MODULE_AUTHOR("Hu Dongliang");
 339 MODULE_LICENSE("GPL v2");