linux/drivers/rtc/rtc-ls1x.c
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   1/*
   2 * Copyright (c) 2011 Zhao Zhang <zhzhl555@gmail.com>
   3 *
   4 * Derived from driver/rtc/rtc-au1xxx.c
   5 *
   6 * This program is free software; you can redistribute  it and/or modify it
   7 * under  the terms of  the GNU General  Public License as published by the
   8 * Free Software Foundation;  either version 2 of the  License, or (at your
   9 * option) any later version.
  10 */
  11
  12#include <linux/module.h>
  13#include <linux/kernel.h>
  14#include <linux/rtc.h>
  15#include <linux/init.h>
  16#include <linux/platform_device.h>
  17#include <linux/delay.h>
  18#include <linux/types.h>
  19#include <linux/io.h>
  20#include <asm/mach-loongson1/loongson1.h>
  21
  22#define LS1X_RTC_REG_OFFSET     (LS1X_RTC_BASE + 0x20)
  23#define LS1X_RTC_REGS(x) \
  24                ((void __iomem *)KSEG1ADDR(LS1X_RTC_REG_OFFSET + (x)))
  25
  26/*RTC programmable counters 0 and 1*/
  27#define SYS_COUNTER_CNTRL               (LS1X_RTC_REGS(0x20))
  28#define SYS_CNTRL_ERS                   (1 << 23)
  29#define SYS_CNTRL_RTS                   (1 << 20)
  30#define SYS_CNTRL_RM2                   (1 << 19)
  31#define SYS_CNTRL_RM1                   (1 << 18)
  32#define SYS_CNTRL_RM0                   (1 << 17)
  33#define SYS_CNTRL_RS                    (1 << 16)
  34#define SYS_CNTRL_BP                    (1 << 14)
  35#define SYS_CNTRL_REN                   (1 << 13)
  36#define SYS_CNTRL_BRT                   (1 << 12)
  37#define SYS_CNTRL_TEN                   (1 << 11)
  38#define SYS_CNTRL_BTT                   (1 << 10)
  39#define SYS_CNTRL_E0                    (1 << 8)
  40#define SYS_CNTRL_ETS                   (1 << 7)
  41#define SYS_CNTRL_32S                   (1 << 5)
  42#define SYS_CNTRL_TTS                   (1 << 4)
  43#define SYS_CNTRL_TM2                   (1 << 3)
  44#define SYS_CNTRL_TM1                   (1 << 2)
  45#define SYS_CNTRL_TM0                   (1 << 1)
  46#define SYS_CNTRL_TS                    (1 << 0)
  47
  48/* Programmable Counter 0 Registers */
  49#define SYS_TOYTRIM             (LS1X_RTC_REGS(0))
  50#define SYS_TOYWRITE0           (LS1X_RTC_REGS(4))
  51#define SYS_TOYWRITE1           (LS1X_RTC_REGS(8))
  52#define SYS_TOYREAD0            (LS1X_RTC_REGS(0xC))
  53#define SYS_TOYREAD1            (LS1X_RTC_REGS(0x10))
  54#define SYS_TOYMATCH0           (LS1X_RTC_REGS(0x14))
  55#define SYS_TOYMATCH1           (LS1X_RTC_REGS(0x18))
  56#define SYS_TOYMATCH2           (LS1X_RTC_REGS(0x1C))
  57
  58/* Programmable Counter 1 Registers */
  59#define SYS_RTCTRIM             (LS1X_RTC_REGS(0x40))
  60#define SYS_RTCWRITE0           (LS1X_RTC_REGS(0x44))
  61#define SYS_RTCREAD0            (LS1X_RTC_REGS(0x48))
  62#define SYS_RTCMATCH0           (LS1X_RTC_REGS(0x4C))
  63#define SYS_RTCMATCH1           (LS1X_RTC_REGS(0x50))
  64#define SYS_RTCMATCH2           (LS1X_RTC_REGS(0x54))
  65
  66#define LS1X_SEC_OFFSET         (4)
  67#define LS1X_MIN_OFFSET         (10)
  68#define LS1X_HOUR_OFFSET        (16)
  69#define LS1X_DAY_OFFSET         (21)
  70#define LS1X_MONTH_OFFSET       (26)
  71
  72
  73#define LS1X_SEC_MASK           (0x3f)
  74#define LS1X_MIN_MASK           (0x3f)
  75#define LS1X_HOUR_MASK          (0x1f)
  76#define LS1X_DAY_MASK           (0x1f)
  77#define LS1X_MONTH_MASK         (0x3f)
  78#define LS1X_YEAR_MASK          (0xffffffff)
  79
  80#define ls1x_get_sec(t)         (((t) >> LS1X_SEC_OFFSET) & LS1X_SEC_MASK)
  81#define ls1x_get_min(t)         (((t) >> LS1X_MIN_OFFSET) & LS1X_MIN_MASK)
  82#define ls1x_get_hour(t)        (((t) >> LS1X_HOUR_OFFSET) & LS1X_HOUR_MASK)
  83#define ls1x_get_day(t)         (((t) >> LS1X_DAY_OFFSET) & LS1X_DAY_MASK)
  84#define ls1x_get_month(t)       (((t) >> LS1X_MONTH_OFFSET) & LS1X_MONTH_MASK)
  85
  86#define RTC_CNTR_OK (SYS_CNTRL_E0 | SYS_CNTRL_32S)
  87
  88static int ls1x_rtc_read_time(struct device *dev, struct rtc_time *rtm)
  89{
  90        unsigned long v, t;
  91
  92        v = readl(SYS_TOYREAD0);
  93        t = readl(SYS_TOYREAD1);
  94
  95        memset(rtm, 0, sizeof(struct rtc_time));
  96        t  = mktime((t & LS1X_YEAR_MASK), ls1x_get_month(v),
  97                        ls1x_get_day(v), ls1x_get_hour(v),
  98                        ls1x_get_min(v), ls1x_get_sec(v));
  99        rtc_time_to_tm(t, rtm);
 100
 101        return rtc_valid_tm(rtm);
 102}
 103
 104static int ls1x_rtc_set_time(struct device *dev, struct  rtc_time *rtm)
 105{
 106        unsigned long v, t, c;
 107        int ret = -ETIMEDOUT;
 108
 109        v = ((rtm->tm_mon + 1)  << LS1X_MONTH_OFFSET)
 110                | (rtm->tm_mday << LS1X_DAY_OFFSET)
 111                | (rtm->tm_hour << LS1X_HOUR_OFFSET)
 112                | (rtm->tm_min  << LS1X_MIN_OFFSET)
 113                | (rtm->tm_sec  << LS1X_SEC_OFFSET);
 114
 115        writel(v, SYS_TOYWRITE0);
 116        c = 0x10000;
 117        /* add timeout check counter, for more safe */
 118        while ((readl(SYS_COUNTER_CNTRL) & SYS_CNTRL_TS) && --c)
 119                usleep_range(1000, 3000);
 120
 121        if (!c) {
 122                dev_err(dev, "set time timeout!\n");
 123                goto err;
 124        }
 125
 126        t = rtm->tm_year + 1900;
 127        writel(t, SYS_TOYWRITE1);
 128        c = 0x10000;
 129        while ((readl(SYS_COUNTER_CNTRL) & SYS_CNTRL_TS) && --c)
 130                usleep_range(1000, 3000);
 131
 132        if (!c) {
 133                dev_err(dev, "set time timeout!\n");
 134                goto err;
 135        }
 136        return 0;
 137err:
 138        return ret;
 139}
 140
 141static struct rtc_class_ops  ls1x_rtc_ops = {
 142        .read_time      = ls1x_rtc_read_time,
 143        .set_time       = ls1x_rtc_set_time,
 144};
 145
 146static int __devinit ls1x_rtc_probe(struct platform_device *pdev)
 147{
 148        struct rtc_device *rtcdev;
 149        unsigned long v;
 150        int ret;
 151
 152        v = readl(SYS_COUNTER_CNTRL);
 153        if (!(v & RTC_CNTR_OK)) {
 154                dev_err(&pdev->dev, "rtc counters not working\n");
 155                ret = -ENODEV;
 156                goto err;
 157        }
 158        ret = -ETIMEDOUT;
 159        /* set to 1 HZ if needed */
 160        if (readl(SYS_TOYTRIM) != 32767) {
 161                v = 0x100000;
 162                while ((readl(SYS_COUNTER_CNTRL) & SYS_CNTRL_TTS) && --v)
 163                        usleep_range(1000, 3000);
 164
 165                if (!v) {
 166                        dev_err(&pdev->dev, "time out\n");
 167                        goto err;
 168                }
 169                writel(32767, SYS_TOYTRIM);
 170        }
 171        /* this loop coundn't be endless */
 172        while (readl(SYS_COUNTER_CNTRL) & SYS_CNTRL_TTS)
 173                usleep_range(1000, 3000);
 174
 175        rtcdev = rtc_device_register("ls1x-rtc", &pdev->dev,
 176                                        &ls1x_rtc_ops , THIS_MODULE);
 177        if (IS_ERR(rtcdev)) {
 178                ret = PTR_ERR(rtcdev);
 179                goto err;
 180        }
 181
 182        platform_set_drvdata(pdev, rtcdev);
 183        return 0;
 184err:
 185        return ret;
 186}
 187
 188static int __devexit ls1x_rtc_remove(struct platform_device *pdev)
 189{
 190        struct rtc_device *rtcdev = platform_get_drvdata(pdev);
 191
 192        rtc_device_unregister(rtcdev);
 193        platform_set_drvdata(pdev, NULL);
 194
 195        return 0;
 196}
 197
 198static struct platform_driver  ls1x_rtc_driver = {
 199        .driver         = {
 200                .name   = "ls1x-rtc",
 201                .owner  = THIS_MODULE,
 202        },
 203        .remove         = __devexit_p(ls1x_rtc_remove),
 204        .probe          = ls1x_rtc_probe,
 205};
 206
 207module_platform_driver(ls1x_rtc_driver);
 208
 209MODULE_AUTHOR("zhao zhang <zhzhl555@gmail.com>");
 210MODULE_LICENSE("GPL");
 211
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