LXR linux/drivers/rtc/rtc-pl030.c

   1/*
   2 *  linux/drivers/rtc/rtc-pl030.c
   3 *
   4 *  Copyright (C) 2000-2001 Deep Blue Solutions Ltd.
   5 *
   6 * This program is free software; you can redistribute it and/or modify
   7 * it under the terms of the GNU General Public License version 2 as
   8 * published by the Free Software Foundation.
   9 */
  10#include <linux/module.h>
  11#include <linux/rtc.h>
  12#include <linux/init.h>
  13#include <linux/interrupt.h>
  14#include <linux/amba/bus.h>
  15#include <linux/io.h>
  16
  17#define RTC_DR          (0)
  18#define RTC_MR          (4)
  19#define RTC_STAT        (8)
  20#define RTC_EOI         (8)
  21#define RTC_LR          (12)
  22#define RTC_CR          (16)
  23#define RTC_CR_MIE      (1 << 0)
  24
  25struct pl030_rtc {
  26        struct rtc_device       *rtc;
  27        void __iomem            *base;
  28};
  29
  30static irqreturn_t pl030_interrupt(int irq, void *dev_id)
  31{
  32        struct pl030_rtc *rtc = dev_id;
  33        writel(0, rtc->base + RTC_EOI);
  34        return IRQ_HANDLED;
  35}
  36
  37static int pl030_ioctl(struct device *dev, unsigned int cmd, unsigned long arg)
  38{
  39        return -ENOIOCTLCMD;
  40}
  41
  42static int pl030_read_alarm(struct device *dev, struct rtc_wkalrm *alrm)
  43{
  44        struct pl030_rtc *rtc = dev_get_drvdata(dev);
  45
  46        rtc_time_to_tm(readl(rtc->base + RTC_MR), &alrm->time);
  47        return 0;
  48}
  49
  50static int pl030_set_alarm(struct device *dev, struct rtc_wkalrm *alrm)
  51{
  52        struct pl030_rtc *rtc = dev_get_drvdata(dev);
  53        unsigned long time;
  54        int ret;
  55
  56        /*
  57         * At the moment, we can only deal with non-wildcarded alarm times.
  58         */
  59        ret = rtc_valid_tm(&alrm->time);
  60        if (ret == 0)
  61                ret = rtc_tm_to_time(&alrm->time, &time);
  62        if (ret == 0)
  63                writel(time, rtc->base + RTC_MR);
  64        return ret;
  65}
  66
  67static int pl030_read_time(struct device *dev, struct rtc_time *tm)
  68{
  69        struct pl030_rtc *rtc = dev_get_drvdata(dev);
  70
  71        rtc_time_to_tm(readl(rtc->base + RTC_DR), tm);
  72
  73        return 0;
  74}
  75
  76/*
  77 * Set the RTC time.  Unfortunately, we can't accurately set
  78 * the point at which the counter updates.
  79 *
  80 * Also, since RTC_LR is transferred to RTC_CR on next rising
  81 * edge of the 1Hz clock, we must write the time one second
  82 * in advance.
  83 */
  84static int pl030_set_time(struct device *dev, struct rtc_time *tm)
  85{
  86        struct pl030_rtc *rtc = dev_get_drvdata(dev);
  87        unsigned long time;
  88        int ret;
  89
  90        ret = rtc_tm_to_time(tm, &time);
  91        if (ret == 0)
  92                writel(time + 1, rtc->base + RTC_LR);
  93
  94        return ret;
  95}
  96
  97static const struct rtc_class_ops pl030_ops = {
  98        .ioctl          = pl030_ioctl,
  99        .read_time      = pl030_read_time,
 100        .set_time       = pl030_set_time,
 101        .read_alarm     = pl030_read_alarm,
 102        .set_alarm      = pl030_set_alarm,
 103};
 104
 105static int pl030_probe(struct amba_device *dev, struct amba_id *id)
 106{
 107        struct pl030_rtc *rtc;
 108        int ret;
 109
 110        ret = amba_request_regions(dev, NULL);
 111        if (ret)
 112                goto err_req;
 113
 114        rtc = kmalloc(sizeof(*rtc), GFP_KERNEL);
 115        if (!rtc) {
 116                ret = -ENOMEM;
 117                goto err_rtc;
 118        }
 119
 120        rtc->base = ioremap(dev->res.start, SZ_4K);
 121        if (!rtc->base) {
 122                ret = -ENOMEM;
 123                goto err_map;
 124        }
 125
 126        __raw_writel(0, rtc->base + RTC_CR);
 127        __raw_writel(0, rtc->base + RTC_EOI);
 128
 129        amba_set_drvdata(dev, rtc);
 130
 131        ret = request_irq(dev->irq[0], pl030_interrupt, IRQF_DISABLED,
 132                          "rtc-pl030", rtc);
 133        if (ret)
 134                goto err_irq;
 135
 136        rtc->rtc = rtc_device_register("pl030", &dev->dev, &pl030_ops,
 137                                       THIS_MODULE);
 138        if (IS_ERR(rtc->rtc)) {
 139                ret = PTR_ERR(rtc->rtc);
 140                goto err_reg;
 141        }
 142
 143        return 0;
 144
 145 err_reg:
 146        free_irq(dev->irq[0], rtc);
 147 err_irq:
 148        iounmap(rtc->base);
 149 err_map:
 150        kfree(rtc);
 151 err_rtc:
 152        amba_release_regions(dev);
 153 err_req:
 154        return ret;
 155}
 156
 157static int pl030_remove(struct amba_device *dev)
 158{
 159        struct pl030_rtc *rtc = amba_get_drvdata(dev);
 160
 161        amba_set_drvdata(dev, NULL);
 162
 163        writel(0, rtc->base + RTC_CR);
 164
 165        free_irq(dev->irq[0], rtc);
 166        rtc_device_unregister(rtc->rtc);
 167        iounmap(rtc->base);
 168        kfree(rtc);
 169        amba_release_regions(dev);
 170
 171        return 0;
 172}
 173
 174static struct amba_id pl030_ids[] = {
 175        {
 176                .id     = 0x00041030,
 177                .mask   = 0x000fffff,
 178        },
 179        { 0, 0 },
 180};
 181
 182static struct amba_driver pl030_driver = {
 183        .drv            = {
 184                .name   = "rtc-pl030",
 185        },
 186        .probe          = pl030_probe,
 187        .remove         = pl030_remove,
 188        .id_table       = pl030_ids,
 189};
 190
 191static int __init pl030_init(void)
 192{
 193        return amba_driver_register(&pl030_driver);
 194}
 195
 196static void __exit pl030_exit(void)
 197{
 198        amba_driver_unregister(&pl030_driver);
 199}
 200
 201module_init(pl030_init);
 202module_exit(pl030_exit);
 203
 204MODULE_AUTHOR("Russell King <rmk@arm.linux.org.uk>");
 205MODULE_DESCRIPTION("ARM AMBA PL030 RTC Driver");
 206MODULE_LICENSE("GPL");
 207