drivers/rtc/mc146818.c

   1 /*
   2  * (C) Copyright 2001
   3  * Denis Peter MPL AG Switzerland. d.peter@mpl.ch
   4  *
   5  * SPDX-License-Identifier:     GPL-2.0+
   6  */
   7
   8 /*
   9  * Date & Time support for the MC146818 (PIXX4) RTC
  10  */
  11
  12 #include <common.h>
  13 #include <command.h>
  14 #include <dm.h>
  15 #include <rtc.h>
  16
  17 #if defined(__I386__) || defined(CONFIG_MALTA)
  18 #include <asm/io.h>
  19 #define in8(p) inb(p)
  20 #define out8(p, v) outb(v, p)
  21 #endif
  22
  23 #if defined(CONFIG_CMD_DATE)
  24
  25 /* Set this to 1 to clear the CMOS RAM */
  26 #define CLEAR_CMOS              0
  27
  28 #define RTC_PORT_MC146818       CONFIG_SYS_ISA_IO_BASE_ADDRESS + 0x70
  29 #define RTC_SECONDS             0x00
  30 #define RTC_SECONDS_ALARM       0x01
  31 #define RTC_MINUTES             0x02
  32 #define RTC_MINUTES_ALARM       0x03
  33 #define RTC_HOURS               0x04
  34 #define RTC_HOURS_ALARM         0x05
  35 #define RTC_DAY_OF_WEEK         0x06
  36 #define RTC_DATE_OF_MONTH       0x07
  37 #define RTC_MONTH               0x08
  38 #define RTC_YEAR                0x09
  39 #define RTC_CONFIG_A            0x0a
  40 #define RTC_CONFIG_B            0x0b
  41 #define RTC_CONFIG_C            0x0c
  42 #define RTC_CONFIG_D            0x0d
  43 #define RTC_REG_SIZE            0x80
  44
  45 #define RTC_CONFIG_A_REF_CLCK_32KHZ     (1 << 5)
  46 #define RTC_CONFIG_A_RATE_1024HZ        6
  47
  48 #define RTC_CONFIG_B_24H                (1 << 1)
  49
  50 #define RTC_CONFIG_D_VALID_RAM_AND_TIME 0x80
  51
  52 static int mc146818_read8(int reg)
  53 {
  54 #ifdef CONFIG_SYS_RTC_REG_BASE_ADDR
  55         return in8(CONFIG_SYS_RTC_REG_BASE_ADDR + reg);
  56 #else
  57         int ofs = 0;
  58
  59         if (reg >= 128) {
  60                 ofs = 2;
  61                 reg -= 128;
  62         }
  63         out8(RTC_PORT_MC146818 + ofs, reg);
  64
  65         return in8(RTC_PORT_MC146818 + ofs + 1);
  66 #endif
  67 }
  68
  69 static void mc146818_write8(int reg, uchar val)
  70 {
  71 #ifdef CONFIG_SYS_RTC_REG_BASE_ADDR
  72         out8(CONFIG_SYS_RTC_REG_BASE_ADDR + reg, val);
  73 #else
  74         int ofs = 0;
  75
  76         if (reg >= 128) {
  77                 ofs = 2;
  78                 reg -= 128;
  79         }
  80         out8(RTC_PORT_MC146818 + ofs, reg);
  81         out8(RTC_PORT_MC146818 + ofs + 1, val);
  82 #endif
  83 }
  84
  85 static int mc146818_get(struct rtc_time *tmp)
  86 {
  87         uchar sec, min, hour, mday, wday, mon, year;
  88
  89         /* here check if rtc can be accessed */
  90         while ((mc146818_read8(RTC_CONFIG_A) & 0x80) == 0x80)
  91                 ;
  92
  93         sec     = mc146818_read8(RTC_SECONDS);
  94         min     = mc146818_read8(RTC_MINUTES);
  95         hour    = mc146818_read8(RTC_HOURS);
  96         mday    = mc146818_read8(RTC_DATE_OF_MONTH);
  97         wday    = mc146818_read8(RTC_DAY_OF_WEEK);
  98         mon     = mc146818_read8(RTC_MONTH);
  99         year    = mc146818_read8(RTC_YEAR);
 100 #ifdef RTC_DEBUG
 101         printf("Get RTC year: %02x mon/cent: %02x mday: %02x wday: %02x hr: %02x min: %02x sec: %02x\n",
 102                year, mon, mday, wday, hour, min, sec);
 103         printf("Alarms: month: %02x hour: %02x min: %02x sec: %02x\n",
 104                mc146818_read8(RTC_CONFIG_D) & 0x3f,
 105                mc146818_read8(RTC_HOURS_ALARM),
 106                mc146818_read8(RTC_MINUTES_ALARM),
 107                mc146818_read8(RTC_SECONDS_ALARM));
 108 #endif
 109         tmp->tm_sec  = bcd2bin(sec & 0x7f);
 110         tmp->tm_min  = bcd2bin(min & 0x7f);
 111         tmp->tm_hour = bcd2bin(hour & 0x3f);
 112         tmp->tm_mday = bcd2bin(mday & 0x3f);
 113         tmp->tm_mon  = bcd2bin(mon & 0x1f);
 114         tmp->tm_year = bcd2bin(year);
 115         tmp->tm_wday = bcd2bin(wday & 0x07);
 116
 117         if (tmp->tm_year < 70)
 118                 tmp->tm_year += 2000;
 119         else
 120                 tmp->tm_year += 1900;
 121
 122         tmp->tm_yday = 0;
 123         tmp->tm_isdst = 0;
 124 #ifdef RTC_DEBUG
 125         printf("Get DATE: %4d-%02d-%02d (wday=%d)  TIME: %2d:%02d:%02d\n",
 126                tmp->tm_year, tmp->tm_mon, tmp->tm_mday, tmp->tm_wday,
 127                tmp->tm_hour, tmp->tm_min, tmp->tm_sec);
 128 #endif
 129
 130         return 0;
 131 }
 132
 133 static int mc146818_set(struct rtc_time *tmp)
 134 {
 135 #ifdef RTC_DEBUG
 136         printf("Set DATE: %4d-%02d-%02d (wday=%d)  TIME: %2d:%02d:%02d\n",
 137                tmp->tm_year, tmp->tm_mon, tmp->tm_mday, tmp->tm_wday,
 138                tmp->tm_hour, tmp->tm_min, tmp->tm_sec);
 139 #endif
 140         /* Disable the RTC to update the regs */
 141         mc146818_write8(RTC_CONFIG_B, 0x82);
 142
 143         mc146818_write8(RTC_YEAR, bin2bcd(tmp->tm_year % 100));
 144         mc146818_write8(RTC_MONTH, bin2bcd(tmp->tm_mon));
 145         mc146818_write8(RTC_DAY_OF_WEEK, bin2bcd(tmp->tm_wday));
 146         mc146818_write8(RTC_DATE_OF_MONTH, bin2bcd(tmp->tm_mday));
 147         mc146818_write8(RTC_HOURS, bin2bcd(tmp->tm_hour));
 148         mc146818_write8(RTC_MINUTES, bin2bcd(tmp->tm_min));
 149         mc146818_write8(RTC_SECONDS, bin2bcd(tmp->tm_sec));
 150
 151         /* Enable the RTC to update the regs */
 152         mc146818_write8(RTC_CONFIG_B, 0x02);
 153
 154         return 0;
 155 }
 156
 157 static void mc146818_reset(void)
 158 {
 159         /* Disable the RTC to update the regs */
 160         mc146818_write8(RTC_CONFIG_B, 0x82);
 161
 162         /* Normal OP */
 163         mc146818_write8(RTC_CONFIG_A, 0x20);
 164         mc146818_write8(RTC_CONFIG_B, 0x00);
 165         mc146818_write8(RTC_CONFIG_B, 0x00);
 166
 167         /* Enable the RTC to update the regs */
 168         mc146818_write8(RTC_CONFIG_B, 0x02);
 169 }
 170
 171 static void mc146818_init(void)
 172 {
 173 #if CLEAR_CMOS
 174         int i;
 175
 176         rtc_write8(RTC_SECONDS_ALARM, 0);
 177         rtc_write8(RTC_MINUTES_ALARM, 0);
 178         rtc_write8(RTC_HOURS_ALARM, 0);
 179         for (i = RTC_CONFIG_A; i < RTC_REG_SIZE; i++)
 180                 rtc_write8(i, 0);
 181         printf("RTC: zeroing CMOS RAM\n");
 182 #endif
 183
 184         /* Setup the real time clock */
 185         mc146818_write8(RTC_CONFIG_B, RTC_CONFIG_B_24H);
 186         /* Setup the frequency it operates at */
 187         mc146818_write8(RTC_CONFIG_A, RTC_CONFIG_A_REF_CLCK_32KHZ |
 188                         RTC_CONFIG_A_RATE_1024HZ);
 189         /* Ensure all reserved bits are 0 in register D */
 190         mc146818_write8(RTC_CONFIG_D, RTC_CONFIG_D_VALID_RAM_AND_TIME);
 191
 192         /* Clear any pending interrupts */
 193         mc146818_read8(RTC_CONFIG_C);
 194 }
 195 #endif /* CONFIG_CMD_DATE */
 196
 197 #ifdef CONFIG_DM_RTC
 198
 199 static int rtc_mc146818_get(struct udevice *dev, struct rtc_time *time)
 200 {
 201         return mc146818_get(time);
 202 }
 203
 204 static int rtc_mc146818_set(struct udevice *dev, const struct rtc_time *time)
 205 {
 206         return mc146818_set((struct rtc_time *)time);
 207 }
 208
 209 static int rtc_mc146818_reset(struct udevice *dev)
 210 {
 211         mc146818_reset();
 212
 213         return 0;
 214 }
 215
 216 static int rtc_mc146818_read8(struct udevice *dev, unsigned int reg)
 217 {
 218         return mc146818_read8(reg);
 219 }
 220
 221 static int rtc_mc146818_write8(struct udevice *dev, unsigned int reg, int val)
 222 {
 223         mc146818_write8(reg, val);
 224
 225         return 0;
 226 }
 227
 228 static int rtc_mc146818_probe(struct udevice *dev)
 229 {
 230         mc146818_init();
 231
 232         return 0;
 233 }
 234
 235 static const struct rtc_ops rtc_mc146818_ops = {
 236         .get = rtc_mc146818_get,
 237         .set = rtc_mc146818_set,
 238         .reset = rtc_mc146818_reset,
 239         .read8 = rtc_mc146818_read8,
 240         .write8 = rtc_mc146818_write8,
 241 };
 242
 243 static const struct udevice_id rtc_mc146818_ids[] = {
 244         { .compatible = "motorola,mc146818" },
 245         { }
 246 };
 247
 248 U_BOOT_DRIVER(rtc_mc146818) = {
 249         .name = "rtc_mc146818",
 250         .id = UCLASS_RTC,
 251         .of_match = rtc_mc146818_ids,
 252         .probe = rtc_mc146818_probe,
 253         .ops = &rtc_mc146818_ops,
 254 };
 255
 256 #else /* !CONFIG_DM_RTC */
 257
 258 int rtc_get(struct rtc_time *tmp)
 259 {
 260         return mc146818_get(tmp);
 261 }
 262
 263 int rtc_set(struct rtc_time *tmp)
 264 {
 265         return mc146818_set(tmp);
 266 }
 267
 268 void rtc_reset(void)
 269 {
 270         mc146818_reset();
 271 }
 272
 273 int rtc_read8(int reg)
 274 {
 275         return mc146818_read8(reg);
 276 }
 277
 278 void rtc_write8(int reg, uchar val)
 279 {
 280         mc146818_write8(reg, val);
 281 }
 282
 283 u32 rtc_read32(int reg)
 284 {
 285         u32 value = 0;
 286         int i;
 287
 288         for (i = 0; i < sizeof(value); i++)
 289                 value |= rtc_read8(reg + i) << (i << 3);
 290
 291         return value;
 292 }
 293
 294 void rtc_write32(int reg, u32 value)
 295 {
 296         int i;
 297
 298         for (i = 0; i < sizeof(value); i++)
 299                 rtc_write8(reg + i, (value >> (i << 3)) & 0xff);
 300 }
 301
 302 void rtc_init(void)
 303 {
 304         mc146818_init();
 305 }
 306
 307 #endif /* CONFIG_DM_RTC */