linux/drivers/rtc/rtc-puv3.c
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   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
  29static struct resource *puv3_rtc_mem;
  30
  31static int puv3_rtc_alarmno = IRQ_RTCAlarm;
  32static int puv3_rtc_tickno  = IRQ_RTC;
  33
  34static DEFINE_SPINLOCK(puv3_rtc_pie_lock);
  35
  36/* IRQ Handlers */
  37static 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
  46static 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 */
  56static 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
  70static 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 */
  89static 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
 100static 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
 114static 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
 130static 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
 153static 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
 160static 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
 189static 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
 200static 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
 210static 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
 223static 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
 239static 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
 308static int ticnt_save;
 309
 310static 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
 318static 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
 329static 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
 340module_platform_driver(puv3_rtc_driver);
 341
 342MODULE_DESCRIPTION("RTC Driver for the PKUnity v3 chip");
 343MODULE_AUTHOR("Hu Dongliang");
 344MODULE_LICENSE("GPL v2");
 345
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