drivers/rtc/rtc-goldfish.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /* drivers/rtc/rtc-goldfish.c
   3  *
   4  * Copyright (C) 2007 Google, Inc.
   5  * Copyright (C) 2017 Imagination Technologies Ltd.
   6  */
   7
   8 #include <linux/io.h>
   9 #include <linux/module.h>
  10 #include <linux/of.h>
  11 #include <linux/platform_device.h>
  12 #include <linux/rtc.h>
  13 #include <linux/goldfish.h>
  14 #include <clocksource/timer-goldfish.h>
  15
  16 struct goldfish_rtc {
  17         void __iomem *base;
  18         int irq;
  19         struct rtc_device *rtc;
  20 };
  21
  22 static int goldfish_rtc_read_alarm(struct device *dev,
  23                                    struct rtc_wkalrm *alrm)
  24 {
  25         u64 rtc_alarm;
  26         u64 rtc_alarm_low;
  27         u64 rtc_alarm_high;
  28         void __iomem *base;
  29         struct goldfish_rtc *rtcdrv;
  30
  31         rtcdrv = dev_get_drvdata(dev);
  32         base = rtcdrv->base;
  33
  34         rtc_alarm_low = gf_ioread32(base + TIMER_ALARM_LOW);
  35         rtc_alarm_high = gf_ioread32(base + TIMER_ALARM_HIGH);
  36         rtc_alarm = (rtc_alarm_high << 32) | rtc_alarm_low;
  37
  38         do_div(rtc_alarm, NSEC_PER_SEC);
  39         memset(alrm, 0, sizeof(struct rtc_wkalrm));
  40
  41         rtc_time64_to_tm(rtc_alarm, &alrm->time);
  42
  43         if (gf_ioread32(base + TIMER_ALARM_STATUS))
  44                 alrm->enabled = 1;
  45         else
  46                 alrm->enabled = 0;
  47
  48         return 0;
  49 }
  50
  51 static int goldfish_rtc_set_alarm(struct device *dev,
  52                                   struct rtc_wkalrm *alrm)
  53 {
  54         struct goldfish_rtc *rtcdrv;
  55         u64 rtc_alarm64;
  56         u64 rtc_status_reg;
  57         void __iomem *base;
  58
  59         rtcdrv = dev_get_drvdata(dev);
  60         base = rtcdrv->base;
  61
  62         if (alrm->enabled) {
  63                 rtc_alarm64 = rtc_tm_to_time64(&alrm->time) * NSEC_PER_SEC;
  64                 gf_iowrite32((rtc_alarm64 >> 32), base + TIMER_ALARM_HIGH);
  65                 gf_iowrite32(rtc_alarm64, base + TIMER_ALARM_LOW);
  66                 gf_iowrite32(1, base + TIMER_IRQ_ENABLED);
  67         } else {
  68                 /*
  69                  * if this function was called with enabled=0
  70                  * then it could mean that the application is
  71                  * trying to cancel an ongoing alarm
  72                  */
  73                 rtc_status_reg = gf_ioread32(base + TIMER_ALARM_STATUS);
  74                 if (rtc_status_reg)
  75                         gf_iowrite32(1, base + TIMER_CLEAR_ALARM);
  76         }
  77
  78         return 0;
  79 }
  80
  81 static int goldfish_rtc_alarm_irq_enable(struct device *dev,
  82                                          unsigned int enabled)
  83 {
  84         void __iomem *base;
  85         struct goldfish_rtc *rtcdrv;
  86
  87         rtcdrv = dev_get_drvdata(dev);
  88         base = rtcdrv->base;
  89
  90         if (enabled)
  91                 gf_iowrite32(1, base + TIMER_IRQ_ENABLED);
  92         else
  93                 gf_iowrite32(0, base + TIMER_IRQ_ENABLED);
  94
  95         return 0;
  96 }
  97
  98 static irqreturn_t goldfish_rtc_interrupt(int irq, void *dev_id)
  99 {
 100         struct goldfish_rtc *rtcdrv = dev_id;
 101         void __iomem *base = rtcdrv->base;
 102
 103         gf_iowrite32(1, base + TIMER_CLEAR_INTERRUPT);
 104
 105         rtc_update_irq(rtcdrv->rtc, 1, RTC_IRQF | RTC_AF);
 106
 107         return IRQ_HANDLED;
 108 }
 109
 110 static int goldfish_rtc_read_time(struct device *dev, struct rtc_time *tm)
 111 {
 112         struct goldfish_rtc *rtcdrv;
 113         void __iomem *base;
 114         u64 time_high;
 115         u64 time_low;
 116         u64 time;
 117
 118         rtcdrv = dev_get_drvdata(dev);
 119         base = rtcdrv->base;
 120
 121         time_low = gf_ioread32(base + TIMER_TIME_LOW);
 122         time_high = gf_ioread32(base + TIMER_TIME_HIGH);
 123         time = (time_high << 32) | time_low;
 124
 125         do_div(time, NSEC_PER_SEC);
 126
 127         rtc_time64_to_tm(time, tm);
 128
 129         return 0;
 130 }
 131
 132 static int goldfish_rtc_set_time(struct device *dev, struct rtc_time *tm)
 133 {
 134         struct goldfish_rtc *rtcdrv;
 135         void __iomem *base;
 136         u64 now64;
 137
 138         rtcdrv = dev_get_drvdata(dev);
 139         base = rtcdrv->base;
 140
 141         now64 = rtc_tm_to_time64(tm) * NSEC_PER_SEC;
 142         gf_iowrite32((now64 >> 32), base + TIMER_TIME_HIGH);
 143         gf_iowrite32(now64, base + TIMER_TIME_LOW);
 144
 145         return 0;
 146 }
 147
 148 static const struct rtc_class_ops goldfish_rtc_ops = {
 149         .read_time      = goldfish_rtc_read_time,
 150         .set_time       = goldfish_rtc_set_time,
 151         .read_alarm     = goldfish_rtc_read_alarm,
 152         .set_alarm      = goldfish_rtc_set_alarm,
 153         .alarm_irq_enable = goldfish_rtc_alarm_irq_enable
 154 };
 155
 156 static int goldfish_rtc_probe(struct platform_device *pdev)
 157 {
 158         struct goldfish_rtc *rtcdrv;
 159         int err;
 160
 161         rtcdrv = devm_kzalloc(&pdev->dev, sizeof(*rtcdrv), GFP_KERNEL);
 162         if (!rtcdrv)
 163                 return -ENOMEM;
 164
 165         platform_set_drvdata(pdev, rtcdrv);
 166         rtcdrv->base = devm_platform_ioremap_resource(pdev, 0);
 167         if (IS_ERR(rtcdrv->base))
 168                 return PTR_ERR(rtcdrv->base);
 169
 170         rtcdrv->irq = platform_get_irq(pdev, 0);
 171         if (rtcdrv->irq < 0)
 172                 return -ENODEV;
 173
 174         rtcdrv->rtc = devm_rtc_allocate_device(&pdev->dev);
 175         if (IS_ERR(rtcdrv->rtc))
 176                 return PTR_ERR(rtcdrv->rtc);
 177
 178         rtcdrv->rtc->ops = &goldfish_rtc_ops;
 179         rtcdrv->rtc->range_max = U64_MAX / NSEC_PER_SEC;
 180
 181         err = devm_request_irq(&pdev->dev, rtcdrv->irq,
 182                                goldfish_rtc_interrupt,
 183                                0, pdev->name, rtcdrv);
 184         if (err)
 185                 return err;
 186
 187         return devm_rtc_register_device(rtcdrv->rtc);
 188 }
 189
 190 static const struct of_device_id goldfish_rtc_of_match[] = {
 191         { .compatible = "google,goldfish-rtc", },
 192         {},
 193 };
 194 MODULE_DEVICE_TABLE(of, goldfish_rtc_of_match);
 195
 196 static struct platform_driver goldfish_rtc = {
 197         .probe = goldfish_rtc_probe,
 198         .driver = {
 199                 .name = "goldfish_rtc",
 200                 .of_match_table = goldfish_rtc_of_match,
 201         }
 202 };
 203
 204 module_platform_driver(goldfish_rtc);
 205
 206 MODULE_DESCRIPTION("Android Goldfish Real Time Clock driver");
 207 MODULE_LICENSE("GPL v2");