1 // SPDX-License-Identifier: GPL-2.0+
4 * Tor Krill, Excito Elektronik i Skåne , tor@excito.com
6 * Modelled after the ds1337 driver
10 * Date & Time support (no alarms) for Intersil
11 * ISL1208 Real Time Clock (RTC).
20 /*---------------------------------------------------------------------*/
22 #define DEBUGR(fmt,args...) printf(fmt ,##args)
24 #define DEBUGR(fmt,args...)
26 /*---------------------------------------------------------------------*/
29 * RTC register addresses
32 #define RTC_SEC_REG_ADDR 0x0
33 #define RTC_MIN_REG_ADDR 0x1
34 #define RTC_HR_REG_ADDR 0x2
35 #define RTC_DATE_REG_ADDR 0x3
36 #define RTC_MON_REG_ADDR 0x4
37 #define RTC_YR_REG_ADDR 0x5
38 #define RTC_DAY_REG_ADDR 0x6
39 #define RTC_STAT_REG_ADDR 0x7
41 * RTC control register bits
45 * RTC status register bits
47 #define RTC_STAT_BIT_ARST 0x80 /* AUTO RESET ENABLE BIT */
48 #define RTC_STAT_BIT_XTOSCB 0x40 /* CRYSTAL OSCILLATOR ENABLE BIT */
49 #define RTC_STAT_BIT_WRTC 0x10 /* WRITE RTC ENABLE BIT */
50 #define RTC_STAT_BIT_ALM 0x04 /* ALARM BIT */
51 #define RTC_STAT_BIT_BAT 0x02 /* BATTERY BIT */
52 #define RTC_STAT_BIT_RTCF 0x01 /* REAL TIME CLOCK FAIL BIT */
55 * Read an RTC register
58 static int isl1208_rtc_read8(struct udevice *dev, unsigned int reg)
60 return dm_i2c_reg_read(dev, reg);
64 * Write an RTC register
67 static int isl1208_rtc_write8(struct udevice *dev, unsigned int reg, int val)
69 return dm_i2c_reg_write(dev, reg, val);
73 * Get the current time from the RTC
76 static int isl1208_rtc_get(struct udevice *dev, struct rtc_time *tmp)
81 ret = dm_i2c_read(dev, 0, buf, sizeof(buf));
85 if (buf[RTC_STAT_REG_ADDR] & RTC_STAT_BIT_RTCF) {
86 printf ("### Warning: RTC oscillator has stopped\n");
87 ret = dm_i2c_read(dev, RTC_STAT_REG_ADDR, &val, sizeof(val));
91 val = val & ~(RTC_STAT_BIT_BAT | RTC_STAT_BIT_RTCF);
92 ret = dm_i2c_write(dev, RTC_STAT_REG_ADDR, &val, sizeof(val));
97 tmp->tm_sec = bcd2bin(buf[RTC_SEC_REG_ADDR] & 0x7F);
98 tmp->tm_min = bcd2bin(buf[RTC_MIN_REG_ADDR] & 0x7F);
99 tmp->tm_hour = bcd2bin(buf[RTC_HR_REG_ADDR] & 0x3F);
100 tmp->tm_mday = bcd2bin(buf[RTC_DATE_REG_ADDR] & 0x3F);
101 tmp->tm_mon = bcd2bin(buf[RTC_MON_REG_ADDR] & 0x1F);
102 tmp->tm_year = bcd2bin(buf[RTC_YR_REG_ADDR]) + 2000;
103 tmp->tm_wday = bcd2bin(buf[RTC_DAY_REG_ADDR] & 0x07);
107 DEBUGR ("Get DATE: %4d-%02d-%02d (wday=%d) TIME: %2d:%02d:%02d\n",
108 tmp->tm_year, tmp->tm_mon, tmp->tm_mday, tmp->tm_wday,
109 tmp->tm_hour, tmp->tm_min, tmp->tm_sec);
117 static int isl1208_rtc_set(struct udevice *dev, const struct rtc_time *tmp)
122 DEBUGR ("Set DATE: %4d-%02d-%02d (wday=%d) TIME: %2d:%02d:%02d\n",
123 tmp->tm_year, tmp->tm_mon, tmp->tm_mday, tmp->tm_wday,
124 tmp->tm_hour, tmp->tm_min, tmp->tm_sec);
126 if (tmp->tm_year < 2000 || tmp->tm_year > 2099)
127 printf("WARNING: year should be between 2000 and 2099!\n");
130 ret = dm_i2c_read(dev, RTC_STAT_REG_ADDR, &val, sizeof(val));
134 val = val | RTC_STAT_BIT_WRTC;
136 ret = dm_i2c_write(dev, RTC_STAT_REG_ADDR, &val, sizeof(val));
140 buf[RTC_YR_REG_ADDR] = bin2bcd(tmp->tm_year % 100);
141 buf[RTC_MON_REG_ADDR] = bin2bcd(tmp->tm_mon);
142 buf[RTC_DAY_REG_ADDR] = bin2bcd(tmp->tm_wday);
143 buf[RTC_DATE_REG_ADDR] = bin2bcd(tmp->tm_mday);
144 buf[RTC_HR_REG_ADDR] = bin2bcd(tmp->tm_hour) | 0x80; /* 24h clock */
145 buf[RTC_MIN_REG_ADDR] = bin2bcd(tmp->tm_min);
146 buf[RTC_SEC_REG_ADDR] = bin2bcd(tmp->tm_sec);
148 ret = dm_i2c_write(dev, 0, buf, sizeof(buf));
153 ret = dm_i2c_read(dev, RTC_STAT_REG_ADDR, &val, sizeof(val));
157 val = val & ~RTC_STAT_BIT_WRTC;
158 ret = dm_i2c_write(dev, RTC_STAT_REG_ADDR, &val, sizeof(val));
165 static int isl1208_rtc_reset(struct udevice *dev)
170 static int isl1208_probe(struct udevice *dev)
172 i2c_set_chip_flags(dev, DM_I2C_CHIP_RD_ADDRESS |
173 DM_I2C_CHIP_WR_ADDRESS);
178 static const struct rtc_ops isl1208_rtc_ops = {
179 .get = isl1208_rtc_get,
180 .set = isl1208_rtc_set,
181 .reset = isl1208_rtc_reset,
182 .read8 = isl1208_rtc_read8,
183 .write8 = isl1208_rtc_write8,
186 static const struct udevice_id isl1208_rtc_ids[] = {
187 { .compatible = "isil,isl1208" },
191 U_BOOT_DRIVER(rtc_isl1208) = {
192 .name = "rtc-isl1208",
194 .probe = isl1208_probe,
195 .of_match = isl1208_rtc_ids,
196 .ops = &isl1208_rtc_ops,