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 %ptRr\n", rtc_tm);
  94
  95         return 0;
  96 }
  97
  98 static int puv3_rtc_settime(struct device *dev, struct rtc_time *tm)
  99 {
 100         unsigned long rtc_count = 0;
 101
 102         dev_dbg(dev, "set time %ptRr\n", tm);
 103
 104         rtc_tm_to_time(tm, &rtc_count);
 105         writel(rtc_count, RTC_RCNR);
 106
 107         return 0;
 108 }
 109
 110 static int puv3_rtc_getalarm(struct device *dev, struct rtc_wkalrm *alrm)
 111 {
 112         struct rtc_time *alm_tm = &alrm->time;
 113
 114         rtc_time_to_tm(readl(RTC_RTAR), alm_tm);
 115
 116         alrm->enabled = readl(RTC_RTSR) & RTC_RTSR_ALE;
 117
 118         dev_dbg(dev, "read alarm: %d, %ptRr\n", alrm->enabled, alm_tm);
 119
 120         return 0;
 121 }
 122
 123 static int puv3_rtc_setalarm(struct device *dev, struct rtc_wkalrm *alrm)
 124 {
 125         struct rtc_time *tm = &alrm->time;
 126         unsigned long rtcalarm_count = 0;
 127
 128         dev_dbg(dev, "set alarm: %d, %ptRr\n", alrm->enabled, tm);
 129
 130         rtc_tm_to_time(tm, &rtcalarm_count);
 131         writel(rtcalarm_count, RTC_RTAR);
 132
 133         puv3_rtc_setaie(dev, alrm->enabled);
 134
 135         if (alrm->enabled)
 136                 enable_irq_wake(puv3_rtc_alarmno);
 137         else
 138                 disable_irq_wake(puv3_rtc_alarmno);
 139
 140         return 0;
 141 }
 142
 143 static int puv3_rtc_proc(struct device *dev, struct seq_file *seq)
 144 {
 145         seq_printf(seq, "periodic_IRQ\t: %s\n",
 146                      (readl(RTC_RTSR) & RTC_RTSR_HZE) ? "yes" : "no");
 147         return 0;
 148 }
 149
 150 static const struct rtc_class_ops puv3_rtcops = {
 151         .read_time      = puv3_rtc_gettime,
 152         .set_time       = puv3_rtc_settime,
 153         .read_alarm     = puv3_rtc_getalarm,
 154         .set_alarm      = puv3_rtc_setalarm,
 155         .proc           = puv3_rtc_proc,
 156 };
 157
 158 static void puv3_rtc_enable(struct device *dev, int en)
 159 {
 160         if (!en) {
 161                 writel(readl(RTC_RTSR) & ~RTC_RTSR_HZE, RTC_RTSR);
 162         } else {
 163                 /* re-enable the device, and check it is ok */
 164                 if ((readl(RTC_RTSR) & RTC_RTSR_HZE) == 0) {
 165                         dev_info(dev, "rtc disabled, re-enabling\n");
 166                         writel(readl(RTC_RTSR) | RTC_RTSR_HZE, RTC_RTSR);
 167                 }
 168         }
 169 }
 170
 171 static int puv3_rtc_remove(struct platform_device *dev)
 172 {
 173         puv3_rtc_setpie(&dev->dev, 0);
 174         puv3_rtc_setaie(&dev->dev, 0);
 175
 176         release_resource(puv3_rtc_mem);
 177         kfree(puv3_rtc_mem);
 178
 179         return 0;
 180 }
 181
 182 static int puv3_rtc_probe(struct platform_device *pdev)
 183 {
 184         struct rtc_device *rtc;
 185         struct resource *res;
 186         int ret;
 187
 188         dev_dbg(&pdev->dev, "%s: probe=%p\n", __func__, pdev);
 189
 190         /* find the IRQs */
 191         puv3_rtc_tickno = platform_get_irq(pdev, 1);
 192         if (puv3_rtc_tickno < 0) {
 193                 dev_err(&pdev->dev, "no irq for rtc tick\n");
 194                 return -ENOENT;
 195         }
 196
 197         puv3_rtc_alarmno = platform_get_irq(pdev, 0);
 198         if (puv3_rtc_alarmno < 0) {
 199                 dev_err(&pdev->dev, "no irq for alarm\n");
 200                 return -ENOENT;
 201         }
 202
 203         dev_dbg(&pdev->dev, "PKUnity_rtc: tick irq %d, alarm irq %d\n",
 204                  puv3_rtc_tickno, puv3_rtc_alarmno);
 205
 206         rtc = devm_rtc_allocate_device(&pdev->dev);
 207         if (IS_ERR(rtc))
 208                 return PTR_ERR(rtc);
 209
 210         ret = devm_request_irq(&pdev->dev, puv3_rtc_alarmno, puv3_rtc_alarmirq,
 211                                0, "pkunity-rtc alarm", rtc);
 212         if (ret) {
 213                 dev_err(&pdev->dev, "IRQ%d error %d\n", puv3_rtc_alarmno, ret);
 214                 return ret;
 215         }
 216
 217         ret = devm_request_irq(&pdev->dev, puv3_rtc_tickno, puv3_rtc_tickirq,
 218                                0, "pkunity-rtc tick", rtc);
 219         if (ret) {
 220                 dev_err(&pdev->dev, "IRQ%d error %d\n", puv3_rtc_tickno, ret);
 221                 return ret;
 222         }
 223
 224         /* get the memory region */
 225         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 226         if (res == NULL) {
 227                 dev_err(&pdev->dev, "failed to get memory region resource\n");
 228                 return -ENOENT;
 229         }
 230
 231         puv3_rtc_mem = request_mem_region(res->start, resource_size(res),
 232                                           pdev->name);
 233
 234         if (puv3_rtc_mem == NULL) {
 235                 dev_err(&pdev->dev, "failed to reserve memory region\n");
 236                 ret = -ENOENT;
 237                 goto err_nores;
 238         }
 239
 240         puv3_rtc_enable(&pdev->dev, 1);
 241
 242         /* register RTC and exit */
 243         rtc->ops = &puv3_rtcops;
 244         ret = rtc_register_device(rtc);
 245         if (ret) {
 246                 dev_err(&pdev->dev, "cannot attach rtc\n");
 247                 goto err_nortc;
 248         }
 249
 250         /* platform setup code should have handled this; sigh */
 251         if (!device_can_wakeup(&pdev->dev))
 252                 device_init_wakeup(&pdev->dev, 1);
 253
 254         platform_set_drvdata(pdev, rtc);
 255         return 0;
 256
 257  err_nortc:
 258         puv3_rtc_enable(&pdev->dev, 0);
 259         release_resource(puv3_rtc_mem);
 260
 261  err_nores:
 262         return ret;
 263 }
 264
 265 #ifdef CONFIG_PM_SLEEP
 266 static int ticnt_save;
 267
 268 static int puv3_rtc_suspend(struct device *dev)
 269 {
 270         /* save RTAR for anyone using periodic interrupts */
 271         ticnt_save = readl(RTC_RTAR);
 272         puv3_rtc_enable(dev, 0);
 273         return 0;
 274 }
 275
 276 static int puv3_rtc_resume(struct device *dev)
 277 {
 278         puv3_rtc_enable(dev, 1);
 279         writel(ticnt_save, RTC_RTAR);
 280         return 0;
 281 }
 282 #endif
 283
 284 static SIMPLE_DEV_PM_OPS(puv3_rtc_pm_ops, puv3_rtc_suspend, puv3_rtc_resume);
 285
 286 static struct platform_driver puv3_rtc_driver = {
 287         .probe          = puv3_rtc_probe,
 288         .remove         = puv3_rtc_remove,
 289         .driver         = {
 290                 .name   = "PKUnity-v3-RTC",
 291                 .pm     = &puv3_rtc_pm_ops,
 292         }
 293 };
 294
 295 module_platform_driver(puv3_rtc_driver);
 296
 297 MODULE_DESCRIPTION("RTC Driver for the PKUnity v3 chip");
 298 MODULE_AUTHOR("Hu Dongliang");
 299 MODULE_LICENSE("GPL v2");