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_time_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         unsigned long rtc_count = 0;
  98
  99         dev_dbg(dev, "set time %ptRr\n", tm);
 100
 101         rtc_tm_to_time(tm, &rtc_count);
 102         writel(rtc_count, RTC_RCNR);
 103
 104         return 0;
 105 }
 106
 107 static int puv3_rtc_getalarm(struct device *dev, struct rtc_wkalrm *alrm)
 108 {
 109         struct rtc_time *alm_tm = &alrm->time;
 110
 111         rtc_time_to_tm(readl(RTC_RTAR), alm_tm);
 112
 113         alrm->enabled = readl(RTC_RTSR) & RTC_RTSR_ALE;
 114
 115         dev_dbg(dev, "read alarm: %d, %ptRr\n", alrm->enabled, alm_tm);
 116
 117         return 0;
 118 }
 119
 120 static int puv3_rtc_setalarm(struct device *dev, struct rtc_wkalrm *alrm)
 121 {
 122         struct rtc_time *tm = &alrm->time;
 123         unsigned long rtcalarm_count = 0;
 124
 125         dev_dbg(dev, "set alarm: %d, %ptRr\n", alrm->enabled, tm);
 126
 127         rtc_tm_to_time(tm, &rtcalarm_count);
 128         writel(rtcalarm_count, RTC_RTAR);
 129
 130         puv3_rtc_setaie(dev, alrm->enabled);
 131
 132         if (alrm->enabled)
 133                 enable_irq_wake(puv3_rtc_alarmno);
 134         else
 135                 disable_irq_wake(puv3_rtc_alarmno);
 136
 137         return 0;
 138 }
 139
 140 static int puv3_rtc_proc(struct device *dev, struct seq_file *seq)
 141 {
 142         seq_printf(seq, "periodic_IRQ\t: %s\n",
 143                      (readl(RTC_RTSR) & RTC_RTSR_HZE) ? "yes" : "no");
 144         return 0;
 145 }
 146
 147 static const struct rtc_class_ops puv3_rtcops = {
 148         .read_time      = puv3_rtc_gettime,
 149         .set_time       = puv3_rtc_settime,
 150         .read_alarm     = puv3_rtc_getalarm,
 151         .set_alarm      = puv3_rtc_setalarm,
 152         .proc           = puv3_rtc_proc,
 153 };
 154
 155 static void puv3_rtc_enable(struct device *dev, int en)
 156 {
 157         if (!en) {
 158                 writel(readl(RTC_RTSR) & ~RTC_RTSR_HZE, RTC_RTSR);
 159         } else {
 160                 /* re-enable the device, and check it is ok */
 161                 if ((readl(RTC_RTSR) & RTC_RTSR_HZE) == 0) {
 162                         dev_info(dev, "rtc disabled, re-enabling\n");
 163                         writel(readl(RTC_RTSR) | RTC_RTSR_HZE, RTC_RTSR);
 164                 }
 165         }
 166 }
 167
 168 static int puv3_rtc_remove(struct platform_device *dev)
 169 {
 170         puv3_rtc_setpie(&dev->dev, 0);
 171         puv3_rtc_setaie(&dev->dev, 0);
 172
 173         release_resource(puv3_rtc_mem);
 174         kfree(puv3_rtc_mem);
 175
 176         return 0;
 177 }
 178
 179 static int puv3_rtc_probe(struct platform_device *pdev)
 180 {
 181         struct rtc_device *rtc;
 182         struct resource *res;
 183         int ret;
 184
 185         dev_dbg(&pdev->dev, "%s: probe=%p\n", __func__, pdev);
 186
 187         /* find the IRQs */
 188         puv3_rtc_tickno = platform_get_irq(pdev, 1);
 189         if (puv3_rtc_tickno < 0)
 190                 return -ENOENT;
 191
 192         puv3_rtc_alarmno = platform_get_irq(pdev, 0);
 193         if (puv3_rtc_alarmno < 0)
 194                 return -ENOENT;
 195
 196         dev_dbg(&pdev->dev, "PKUnity_rtc: tick irq %d, alarm irq %d\n",
 197                  puv3_rtc_tickno, puv3_rtc_alarmno);
 198
 199         rtc = devm_rtc_allocate_device(&pdev->dev);
 200         if (IS_ERR(rtc))
 201                 return PTR_ERR(rtc);
 202
 203         ret = devm_request_irq(&pdev->dev, puv3_rtc_alarmno, puv3_rtc_alarmirq,
 204                                0, "pkunity-rtc alarm", rtc);
 205         if (ret) {
 206                 dev_err(&pdev->dev, "IRQ%d error %d\n", puv3_rtc_alarmno, ret);
 207                 return ret;
 208         }
 209
 210         ret = devm_request_irq(&pdev->dev, puv3_rtc_tickno, puv3_rtc_tickirq,
 211                                0, "pkunity-rtc tick", rtc);
 212         if (ret) {
 213                 dev_err(&pdev->dev, "IRQ%d error %d\n", puv3_rtc_tickno, ret);
 214                 return ret;
 215         }
 216
 217         /* get the memory region */
 218         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 219         if (res == NULL) {
 220                 dev_err(&pdev->dev, "failed to get memory region resource\n");
 221                 return -ENOENT;
 222         }
 223
 224         puv3_rtc_mem = request_mem_region(res->start, resource_size(res),
 225                                           pdev->name);
 226
 227         if (puv3_rtc_mem == NULL) {
 228                 dev_err(&pdev->dev, "failed to reserve memory region\n");
 229                 ret = -ENOENT;
 230                 goto err_nores;
 231         }
 232
 233         puv3_rtc_enable(&pdev->dev, 1);
 234
 235         /* register RTC and exit */
 236         rtc->ops = &puv3_rtcops;
 237         ret = rtc_register_device(rtc);
 238         if (ret)
 239                 goto err_nortc;
 240
 241         /* platform setup code should have handled this; sigh */
 242         if (!device_can_wakeup(&pdev->dev))
 243                 device_init_wakeup(&pdev->dev, 1);
 244
 245         platform_set_drvdata(pdev, rtc);
 246         return 0;
 247
 248  err_nortc:
 249         puv3_rtc_enable(&pdev->dev, 0);
 250         release_resource(puv3_rtc_mem);
 251
 252  err_nores:
 253         return ret;
 254 }
 255
 256 #ifdef CONFIG_PM_SLEEP
 257 static int ticnt_save;
 258
 259 static int puv3_rtc_suspend(struct device *dev)
 260 {
 261         /* save RTAR for anyone using periodic interrupts */
 262         ticnt_save = readl(RTC_RTAR);
 263         puv3_rtc_enable(dev, 0);
 264         return 0;
 265 }
 266
 267 static int puv3_rtc_resume(struct device *dev)
 268 {
 269         puv3_rtc_enable(dev, 1);
 270         writel(ticnt_save, RTC_RTAR);
 271         return 0;
 272 }
 273 #endif
 274
 275 static SIMPLE_DEV_PM_OPS(puv3_rtc_pm_ops, puv3_rtc_suspend, puv3_rtc_resume);
 276
 277 static struct platform_driver puv3_rtc_driver = {
 278         .probe          = puv3_rtc_probe,
 279         .remove         = puv3_rtc_remove,
 280         .driver         = {
 281                 .name   = "PKUnity-v3-RTC",
 282                 .pm     = &puv3_rtc_pm_ops,
 283         }
 284 };
 285
 286 module_platform_driver(puv3_rtc_driver);
 287
 288 MODULE_DESCRIPTION("RTC Driver for the PKUnity v3 chip");
 289 MODULE_AUTHOR("Hu Dongliang");
 290 MODULE_LICENSE("GPL v2");