linux/drivers/rtc/rtc-ls1x.c
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   1// SPDX-License-Identifier: GPL-2.0-or-later
   2/*
   3 * Copyright (c) 2011 Zhao Zhang <zhzhl555@gmail.com>
   4 *
   5 * Derived from driver/rtc/rtc-au1xxx.c
   6 */
   7
   8#include <linux/module.h>
   9#include <linux/kernel.h>
  10#include <linux/rtc.h>
  11#include <linux/init.h>
  12#include <linux/platform_device.h>
  13#include <linux/delay.h>
  14#include <linux/types.h>
  15#include <linux/io.h>
  16#include <loongson1.h>
  17
  18#define LS1X_RTC_REG_OFFSET     (LS1X_RTC_BASE + 0x20)
  19#define LS1X_RTC_REGS(x) \
  20                ((void __iomem *)KSEG1ADDR(LS1X_RTC_REG_OFFSET + (x)))
  21
  22/*RTC programmable counters 0 and 1*/
  23#define SYS_COUNTER_CNTRL               (LS1X_RTC_REGS(0x20))
  24#define SYS_CNTRL_ERS                   (1 << 23)
  25#define SYS_CNTRL_RTS                   (1 << 20)
  26#define SYS_CNTRL_RM2                   (1 << 19)
  27#define SYS_CNTRL_RM1                   (1 << 18)
  28#define SYS_CNTRL_RM0                   (1 << 17)
  29#define SYS_CNTRL_RS                    (1 << 16)
  30#define SYS_CNTRL_BP                    (1 << 14)
  31#define SYS_CNTRL_REN                   (1 << 13)
  32#define SYS_CNTRL_BRT                   (1 << 12)
  33#define SYS_CNTRL_TEN                   (1 << 11)
  34#define SYS_CNTRL_BTT                   (1 << 10)
  35#define SYS_CNTRL_E0                    (1 << 8)
  36#define SYS_CNTRL_ETS                   (1 << 7)
  37#define SYS_CNTRL_32S                   (1 << 5)
  38#define SYS_CNTRL_TTS                   (1 << 4)
  39#define SYS_CNTRL_TM2                   (1 << 3)
  40#define SYS_CNTRL_TM1                   (1 << 2)
  41#define SYS_CNTRL_TM0                   (1 << 1)
  42#define SYS_CNTRL_TS                    (1 << 0)
  43
  44/* Programmable Counter 0 Registers */
  45#define SYS_TOYTRIM             (LS1X_RTC_REGS(0))
  46#define SYS_TOYWRITE0           (LS1X_RTC_REGS(4))
  47#define SYS_TOYWRITE1           (LS1X_RTC_REGS(8))
  48#define SYS_TOYREAD0            (LS1X_RTC_REGS(0xC))
  49#define SYS_TOYREAD1            (LS1X_RTC_REGS(0x10))
  50#define SYS_TOYMATCH0           (LS1X_RTC_REGS(0x14))
  51#define SYS_TOYMATCH1           (LS1X_RTC_REGS(0x18))
  52#define SYS_TOYMATCH2           (LS1X_RTC_REGS(0x1C))
  53
  54/* Programmable Counter 1 Registers */
  55#define SYS_RTCTRIM             (LS1X_RTC_REGS(0x40))
  56#define SYS_RTCWRITE0           (LS1X_RTC_REGS(0x44))
  57#define SYS_RTCREAD0            (LS1X_RTC_REGS(0x48))
  58#define SYS_RTCMATCH0           (LS1X_RTC_REGS(0x4C))
  59#define SYS_RTCMATCH1           (LS1X_RTC_REGS(0x50))
  60#define SYS_RTCMATCH2           (LS1X_RTC_REGS(0x54))
  61
  62#define LS1X_SEC_OFFSET         (4)
  63#define LS1X_MIN_OFFSET         (10)
  64#define LS1X_HOUR_OFFSET        (16)
  65#define LS1X_DAY_OFFSET         (21)
  66#define LS1X_MONTH_OFFSET       (26)
  67
  68
  69#define LS1X_SEC_MASK           (0x3f)
  70#define LS1X_MIN_MASK           (0x3f)
  71#define LS1X_HOUR_MASK          (0x1f)
  72#define LS1X_DAY_MASK           (0x1f)
  73#define LS1X_MONTH_MASK         (0x3f)
  74#define LS1X_YEAR_MASK          (0xffffffff)
  75
  76#define ls1x_get_sec(t)         (((t) >> LS1X_SEC_OFFSET) & LS1X_SEC_MASK)
  77#define ls1x_get_min(t)         (((t) >> LS1X_MIN_OFFSET) & LS1X_MIN_MASK)
  78#define ls1x_get_hour(t)        (((t) >> LS1X_HOUR_OFFSET) & LS1X_HOUR_MASK)
  79#define ls1x_get_day(t)         (((t) >> LS1X_DAY_OFFSET) & LS1X_DAY_MASK)
  80#define ls1x_get_month(t)       (((t) >> LS1X_MONTH_OFFSET) & LS1X_MONTH_MASK)
  81
  82#define RTC_CNTR_OK (SYS_CNTRL_E0 | SYS_CNTRL_32S)
  83
  84static int ls1x_rtc_read_time(struct device *dev, struct rtc_time *rtm)
  85{
  86        unsigned long v;
  87        time64_t t;
  88
  89        v = readl(SYS_TOYREAD0);
  90        t = readl(SYS_TOYREAD1);
  91
  92        memset(rtm, 0, sizeof(struct rtc_time));
  93        t  = mktime64((t & LS1X_YEAR_MASK), ls1x_get_month(v),
  94                        ls1x_get_day(v), ls1x_get_hour(v),
  95                        ls1x_get_min(v), ls1x_get_sec(v));
  96        rtc_time64_to_tm(t, rtm);
  97
  98        return 0;
  99}
 100
 101static int ls1x_rtc_set_time(struct device *dev, struct  rtc_time *rtm)
 102{
 103        unsigned long v, t, c;
 104        int ret = -ETIMEDOUT;
 105
 106        v = ((rtm->tm_mon + 1)  << LS1X_MONTH_OFFSET)
 107                | (rtm->tm_mday << LS1X_DAY_OFFSET)
 108                | (rtm->tm_hour << LS1X_HOUR_OFFSET)
 109                | (rtm->tm_min  << LS1X_MIN_OFFSET)
 110                | (rtm->tm_sec  << LS1X_SEC_OFFSET);
 111
 112        writel(v, SYS_TOYWRITE0);
 113        c = 0x10000;
 114        /* add timeout check counter, for more safe */
 115        while ((readl(SYS_COUNTER_CNTRL) & SYS_CNTRL_TS) && --c)
 116                usleep_range(1000, 3000);
 117
 118        if (!c) {
 119                dev_err(dev, "set time timeout!\n");
 120                goto err;
 121        }
 122
 123        t = rtm->tm_year + 1900;
 124        writel(t, SYS_TOYWRITE1);
 125        c = 0x10000;
 126        while ((readl(SYS_COUNTER_CNTRL) & SYS_CNTRL_TS) && --c)
 127                usleep_range(1000, 3000);
 128
 129        if (!c) {
 130                dev_err(dev, "set time timeout!\n");
 131                goto err;
 132        }
 133        return 0;
 134err:
 135        return ret;
 136}
 137
 138static const struct rtc_class_ops  ls1x_rtc_ops = {
 139        .read_time      = ls1x_rtc_read_time,
 140        .set_time       = ls1x_rtc_set_time,
 141};
 142
 143static int ls1x_rtc_probe(struct platform_device *pdev)
 144{
 145        struct rtc_device *rtcdev;
 146        unsigned long v;
 147
 148        v = readl(SYS_COUNTER_CNTRL);
 149        if (!(v & RTC_CNTR_OK)) {
 150                dev_err(&pdev->dev, "rtc counters not working\n");
 151                return -ENODEV;
 152        }
 153
 154        /* set to 1 HZ if needed */
 155        if (readl(SYS_TOYTRIM) != 32767) {
 156                v = 0x100000;
 157                while ((readl(SYS_COUNTER_CNTRL) & SYS_CNTRL_TTS) && --v)
 158                        usleep_range(1000, 3000);
 159
 160                if (!v) {
 161                        dev_err(&pdev->dev, "time out\n");
 162                        return -ETIMEDOUT;
 163                }
 164                writel(32767, SYS_TOYTRIM);
 165        }
 166        /* this loop coundn't be endless */
 167        while (readl(SYS_COUNTER_CNTRL) & SYS_CNTRL_TTS)
 168                usleep_range(1000, 3000);
 169
 170        rtcdev = devm_rtc_allocate_device(&pdev->dev);
 171        if (IS_ERR(rtcdev))
 172                return PTR_ERR(rtcdev);
 173
 174        platform_set_drvdata(pdev, rtcdev);
 175        rtcdev->ops = &ls1x_rtc_ops;
 176        rtcdev->range_min = RTC_TIMESTAMP_BEGIN_1900;
 177        rtcdev->range_max = RTC_TIMESTAMP_END_2099;
 178
 179        return rtc_register_device(rtcdev);
 180}
 181
 182static struct platform_driver  ls1x_rtc_driver = {
 183        .driver         = {
 184                .name   = "ls1x-rtc",
 185        },
 186        .probe          = ls1x_rtc_probe,
 187};
 188
 189module_platform_driver(ls1x_rtc_driver);
 190
 191MODULE_AUTHOR("zhao zhang <zhzhl555@gmail.com>");
 192MODULE_LICENSE("GPL");
 193