drivers/rtc/rtc-puv3.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * RTC driver code specific to PKUnity SoC and UniCore ISA
   4  *
   5  *      Maintained by GUAN Xue-tao <gxt@mprc.pku.edu.cn>
   6  *      Copyright (C) 2001-2010 Guan Xuetao
   7  */
   8
   9 #include <linux/module.h>
  10 #include <linux/fs.h>
  11 #include <linux/string.h>
  12 #include <linux/init.h>
  13 #include <linux/platform_device.h>
  14 #include <linux/interrupt.h>
  15 #include <linux/rtc.h>
  16 #include <linux/bcd.h>
  17 #include <linux/clk.h>
  18 #include <linux/log2.h>
  19 #include <linux/slab.h>
  20 #include <linux/uaccess.h>
  21 #include <linux/io.h>
  22
  23 #include <asm/irq.h>
  24 #include <mach/hardware.h>
  25
  26 static struct resource *puv3_rtc_mem;
  27
  28 static int puv3_rtc_alarmno = IRQ_RTCAlarm;
  29 static int puv3_rtc_tickno  = IRQ_RTC;
  30
  31 static DEFINE_SPINLOCK(puv3_rtc_pie_lock);
  32
  33 /* IRQ Handlers */
  34 static irqreturn_t puv3_rtc_alarmirq(int irq, void *id)
  35 {
  36         struct rtc_device *rdev = id;
  37
  38         writel(readl(RTC_RTSR) | RTC_RTSR_AL, RTC_RTSR);
  39         rtc_update_irq(rdev, 1, RTC_AF | RTC_IRQF);
  40         return IRQ_HANDLED;
  41 }
  42
  43 static irqreturn_t puv3_rtc_tickirq(int irq, void *id)
  44 {
  45         struct rtc_device *rdev = id;
  46
  47         writel(readl(RTC_RTSR) | RTC_RTSR_HZ, RTC_RTSR);
  48         rtc_update_irq(rdev, 1, RTC_PF | RTC_IRQF);
  49         return IRQ_HANDLED;
  50 }
  51
  52 /* Update control registers */
  53 static void puv3_rtc_setaie(struct device *dev, int to)
  54 {
  55         unsigned int tmp;
  56
  57         dev_dbg(dev, "%s: aie=%d\n", __func__, to);
  58
  59         tmp = readl(RTC_RTSR) & ~RTC_RTSR_ALE;
  60
  61         if (to)
  62                 tmp |= RTC_RTSR_ALE;
  63
  64         writel(tmp, RTC_RTSR);
  65 }
  66
  67 static int puv3_rtc_setpie(struct device *dev, int enabled)
  68 {
  69         unsigned int tmp;
  70
  71         dev_dbg(dev, "%s: pie=%d\n", __func__, enabled);
  72
  73         spin_lock_irq(&puv3_rtc_pie_lock);
  74         tmp = readl(RTC_RTSR) & ~RTC_RTSR_HZE;
  75
  76         if (enabled)
  77                 tmp |= RTC_RTSR_HZE;
  78
  79         writel(tmp, RTC_RTSR);
  80         spin_unlock_irq(&puv3_rtc_pie_lock);
  81
  82         return 0;
  83 }
  84
  85 /* Time read/write */
  86 static int puv3_rtc_gettime(struct device *dev, struct rtc_time *rtc_tm)
  87 {
  88         rtc_time64_to_tm(readl(RTC_RCNR), rtc_tm);
  89
  90         dev_dbg(dev, "read time %ptRr\n", rtc_tm);
  91
  92         return 0;
  93 }
  94
  95 static int puv3_rtc_settime(struct device *dev, struct rtc_time *tm)
  96 {
  97         dev_dbg(dev, "set time %ptRr\n", tm);
  98
  99         writel(rtc_tm_to_time64(tm), RTC_RCNR);
 100
 101         return 0;
 102 }
 103
 104 static int puv3_rtc_getalarm(struct device *dev, struct rtc_wkalrm *alrm)
 105 {
 106         struct rtc_time *alm_tm = &alrm->time;
 107
 108         rtc_time64_to_tm(readl(RTC_RTAR), alm_tm);
 109
 110         alrm->enabled = readl(RTC_RTSR) & RTC_RTSR_ALE;
 111
 112         dev_dbg(dev, "read alarm: %d, %ptRr\n", alrm->enabled, alm_tm);
 113
 114         return 0;
 115 }
 116
 117 static int puv3_rtc_setalarm(struct device *dev, struct rtc_wkalrm *alrm)
 118 {
 119         struct rtc_time *tm = &alrm->time;
 120
 121         dev_dbg(dev, "set alarm: %d, %ptRr\n", alrm->enabled, tm);
 122
 123         writel(rtc_tm_to_time64(tm), RTC_RTAR);
 124
 125         puv3_rtc_setaie(dev, alrm->enabled);
 126
 127         if (alrm->enabled)
 128                 enable_irq_wake(puv3_rtc_alarmno);
 129         else
 130                 disable_irq_wake(puv3_rtc_alarmno);
 131
 132         return 0;
 133 }
 134
 135 static int puv3_rtc_proc(struct device *dev, struct seq_file *seq)
 136 {
 137         seq_printf(seq, "periodic_IRQ\t: %s\n",
 138                      (readl(RTC_RTSR) & RTC_RTSR_HZE) ? "yes" : "no");
 139         return 0;
 140 }
 141
 142 static const struct rtc_class_ops puv3_rtcops = {
 143         .read_time      = puv3_rtc_gettime,
 144         .set_time       = puv3_rtc_settime,
 145         .read_alarm     = puv3_rtc_getalarm,
 146         .set_alarm      = puv3_rtc_setalarm,
 147         .proc           = puv3_rtc_proc,
 148 };
 149
 150 static void puv3_rtc_enable(struct device *dev, int en)
 151 {
 152         if (!en) {
 153                 writel(readl(RTC_RTSR) & ~RTC_RTSR_HZE, RTC_RTSR);
 154         } else {
 155                 /* re-enable the device, and check it is ok */
 156                 if ((readl(RTC_RTSR) & RTC_RTSR_HZE) == 0) {
 157                         dev_info(dev, "rtc disabled, re-enabling\n");
 158                         writel(readl(RTC_RTSR) | RTC_RTSR_HZE, RTC_RTSR);
 159                 }
 160         }
 161 }
 162
 163 static int puv3_rtc_remove(struct platform_device *dev)
 164 {
 165         puv3_rtc_setpie(&dev->dev, 0);
 166         puv3_rtc_setaie(&dev->dev, 0);
 167
 168         release_resource(puv3_rtc_mem);
 169         kfree(puv3_rtc_mem);
 170
 171         return 0;
 172 }
 173
 174 static int puv3_rtc_probe(struct platform_device *pdev)
 175 {
 176         struct rtc_device *rtc;
 177         struct resource *res;
 178         int ret;
 179
 180         dev_dbg(&pdev->dev, "%s: probe=%p\n", __func__, pdev);
 181
 182         /* find the IRQs */
 183         puv3_rtc_tickno = platform_get_irq(pdev, 1);
 184         if (puv3_rtc_tickno < 0)
 185                 return -ENOENT;
 186
 187         puv3_rtc_alarmno = platform_get_irq(pdev, 0);
 188         if (puv3_rtc_alarmno < 0)
 189                 return -ENOENT;
 190
 191         dev_dbg(&pdev->dev, "PKUnity_rtc: tick irq %d, alarm irq %d\n",
 192                  puv3_rtc_tickno, puv3_rtc_alarmno);
 193
 194         rtc = devm_rtc_allocate_device(&pdev->dev);
 195         if (IS_ERR(rtc))
 196                 return PTR_ERR(rtc);
 197
 198         ret = devm_request_irq(&pdev->dev, puv3_rtc_alarmno, puv3_rtc_alarmirq,
 199                                0, "pkunity-rtc alarm", rtc);
 200         if (ret) {
 201                 dev_err(&pdev->dev, "IRQ%d error %d\n", puv3_rtc_alarmno, ret);
 202                 return ret;
 203         }
 204
 205         ret = devm_request_irq(&pdev->dev, puv3_rtc_tickno, puv3_rtc_tickirq,
 206                                0, "pkunity-rtc tick", rtc);
 207         if (ret) {
 208                 dev_err(&pdev->dev, "IRQ%d error %d\n", puv3_rtc_tickno, ret);
 209                 return ret;
 210         }
 211
 212         /* get the memory region */
 213         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 214         if (res == NULL) {
 215                 dev_err(&pdev->dev, "failed to get memory region resource\n");
 216                 return -ENOENT;
 217         }
 218
 219         puv3_rtc_mem = request_mem_region(res->start, resource_size(res),
 220                                           pdev->name);
 221
 222         if (puv3_rtc_mem == NULL) {
 223                 dev_err(&pdev->dev, "failed to reserve memory region\n");
 224                 ret = -ENOENT;
 225                 goto err_nores;
 226         }
 227
 228         puv3_rtc_enable(&pdev->dev, 1);
 229
 230         /* register RTC and exit */
 231         rtc->ops = &puv3_rtcops;
 232         rtc->range_max = U32_MAX;
 233         ret = rtc_register_device(rtc);
 234         if (ret)
 235                 goto err_nortc;
 236
 237         /* platform setup code should have handled this; sigh */
 238         if (!device_can_wakeup(&pdev->dev))
 239                 device_init_wakeup(&pdev->dev, 1);
 240
 241         platform_set_drvdata(pdev, rtc);
 242         return 0;
 243
 244  err_nortc:
 245         puv3_rtc_enable(&pdev->dev, 0);
 246         release_resource(puv3_rtc_mem);
 247
 248  err_nores:
 249         return ret;
 250 }
 251
 252 #ifdef CONFIG_PM_SLEEP
 253 static int ticnt_save;
 254
 255 static int puv3_rtc_suspend(struct device *dev)
 256 {
 257         /* save RTAR for anyone using periodic interrupts */
 258         ticnt_save = readl(RTC_RTAR);
 259         puv3_rtc_enable(dev, 0);
 260         return 0;
 261 }
 262
 263 static int puv3_rtc_resume(struct device *dev)
 264 {
 265         puv3_rtc_enable(dev, 1);
 266         writel(ticnt_save, RTC_RTAR);
 267         return 0;
 268 }
 269 #endif
 270
 271 static SIMPLE_DEV_PM_OPS(puv3_rtc_pm_ops, puv3_rtc_suspend, puv3_rtc_resume);
 272
 273 static struct platform_driver puv3_rtc_driver = {
 274         .probe          = puv3_rtc_probe,
 275         .remove         = puv3_rtc_remove,
 276         .driver         = {
 277                 .name   = "PKUnity-v3-RTC",
 278                 .pm     = &puv3_rtc_pm_ops,
 279         }
 280 };
 281
 282 module_platform_driver(puv3_rtc_driver);
 283
 284 MODULE_DESCRIPTION("RTC Driver for the PKUnity v3 chip");
 285 MODULE_AUTHOR("Hu Dongliang");
 286 MODULE_LICENSE("GPL v2");