drivers/rtc/mxsrtc.c

   1 /*
   2  * Freescale i.MX28 RTC Driver
   3  *
   4  * Copyright (C) 2011 Marek Vasut <marek.vasut@gmail.com>
   5  * on behalf of DENX Software Engineering GmbH
   6  *
   7  * SPDX-License-Identifier:     GPL-2.0+
   8  */
   9
  10 #include <common.h>
  11 #include <rtc.h>
  12 #include <asm/io.h>
  13 #include <asm/arch/imx-regs.h>
  14 #include <asm/arch/sys_proto.h>
  15
  16 #define MXS_RTC_MAX_TIMEOUT     1000000
  17
  18 /* Set time in seconds since 1970-01-01 */
  19 int mxs_rtc_set_time(uint32_t secs)
  20 {
  21         struct mxs_rtc_regs *rtc_regs = (struct mxs_rtc_regs *)MXS_RTC_BASE;
  22         int ret;
  23
  24         writel(secs, &rtc_regs->hw_rtc_seconds);
  25
  26         /*
  27          * The 0x80 here means seconds were copied to analog. This information
  28          * is taken from the linux kernel driver for the STMP37xx RTC since
  29          * documentation doesn't mention it.
  30          */
  31         ret = mxs_wait_mask_clr(&rtc_regs->hw_rtc_stat_reg,
  32                 0x80 << RTC_STAT_STALE_REGS_OFFSET, MXS_RTC_MAX_TIMEOUT);
  33
  34         if (ret)
  35                 printf("MXS RTC: Timeout waiting for update\n");
  36
  37         return ret;
  38 }
  39
  40 int rtc_get(struct rtc_time *time)
  41 {
  42         struct mxs_rtc_regs *rtc_regs = (struct mxs_rtc_regs *)MXS_RTC_BASE;
  43         uint32_t secs;
  44
  45         secs = readl(&rtc_regs->hw_rtc_seconds);
  46         rtc_to_tm(secs, time);
  47
  48         return 0;
  49 }
  50
  51 int rtc_set(struct rtc_time *time)
  52 {
  53         uint32_t secs;
  54
  55         secs = rtc_mktime(time);
  56
  57         return mxs_rtc_set_time(secs);
  58 }
  59
  60 void rtc_reset(void)
  61 {
  62         struct mxs_rtc_regs *rtc_regs = (struct mxs_rtc_regs *)MXS_RTC_BASE;
  63         int ret;
  64
  65         /* Set time to 1970-01-01 */
  66         mxs_rtc_set_time(0);
  67
  68         /* Reset the RTC block */
  69         ret = mxs_reset_block(&rtc_regs->hw_rtc_ctrl_reg);
  70         if (ret)
  71                 printf("MXS RTC: Block reset timeout\n");
  72 }