// SPDX-License-Identifier: GPL-2.0+ /* * (C) Copyright 2007 * Matthias Fuchs, esd gmbh, matthias.fuchs@esd-electronics.com. */ /* * Epson RX8025 RTC driver. */ #include #include #include #include #include /*---------------------------------------------------------------------*/ #undef DEBUG_RTC #ifdef DEBUG_RTC #define DEBUGR(fmt,args...) printf(fmt ,##args) #else #define DEBUGR(fmt,args...) #endif /*---------------------------------------------------------------------*/ enum rx_model { model_rx_8025, model_rx_8035, }; /* * RTC register addresses */ #define RTC_SEC_REG_ADDR 0x00 #define RTC_MIN_REG_ADDR 0x01 #define RTC_HR_REG_ADDR 0x02 #define RTC_DAY_REG_ADDR 0x03 #define RTC_DATE_REG_ADDR 0x04 #define RTC_MON_REG_ADDR 0x05 #define RTC_YR_REG_ADDR 0x06 #define RTC_OFFSET_REG_ADDR 0x07 #define RTC_CTL1_REG_ADDR 0x0e #define RTC_CTL2_REG_ADDR 0x0f /* * Control register 1 bits */ #define RTC_CTL1_BIT_2412 0x20 /* * Control register 2 bits */ #define RTC_CTL2_BIT_PON 0x10 #define RTC_CTL2_BIT_VDET 0x40 #define RTC_CTL2_BIT_XST 0x20 #define RTC_CTL2_BIT_VDSL 0x80 /* * Note: the RX8025 I2C RTC requires register * reads and write to consist of a single bus * cycle. It is not allowed to write the register * address in a first cycle that is terminated by * a STOP condition. The chips needs a 'restart' * sequence (start sequence without a prior stop). */ #define rtc_read(reg) buf[(reg) & 0xf] static int rtc_write(struct udevice *dev, uchar reg, uchar val); static int rx8025_is_osc_stopped(enum rx_model model, int ctrl2) { int xstp = ctrl2 & RTC_CTL2_BIT_XST; /* XSTP bit has different polarity on RX-8025 vs RX-8035. * RX-8025: 0 == oscillator stopped * RX-8035: 1 == oscillator stopped */ if (model == model_rx_8025) xstp = !xstp; return xstp; } /* * Get the current time from the RTC */ static int rx8025_rtc_get(struct udevice *dev, struct rtc_time *tmp) { int rel = 0; uchar sec, min, hour, mday, wday, mon, year, ctl2; uchar buf[16]; if (dm_i2c_read(dev, 0, buf, sizeof(buf))) { printf("Error reading from RTC\n"); return -EIO; } sec = rtc_read(RTC_SEC_REG_ADDR); min = rtc_read(RTC_MIN_REG_ADDR); hour = rtc_read(RTC_HR_REG_ADDR); wday = rtc_read(RTC_DAY_REG_ADDR); mday = rtc_read(RTC_DATE_REG_ADDR); mon = rtc_read(RTC_MON_REG_ADDR); year = rtc_read(RTC_YR_REG_ADDR); DEBUGR("Get RTC year: %02x mon: %02x mday: %02x wday: %02x " "hr: %02x min: %02x sec: %02x\n", year, mon, mday, wday, hour, min, sec); /* dump status */ ctl2 = rtc_read(RTC_CTL2_REG_ADDR); if (ctl2 & RTC_CTL2_BIT_PON) { printf("RTC: power-on detected\n"); rel = -1; } if (ctl2 & RTC_CTL2_BIT_VDET) { printf("RTC: voltage drop detected\n"); rel = -1; } if (rx8025_is_osc_stopped(dev->driver_data, ctl2)) { printf("RTC: oscillator stop detected\n"); rel = -1; } tmp->tm_sec = bcd2bin(sec & 0x7F); tmp->tm_min = bcd2bin(min & 0x7F); if (rtc_read(RTC_CTL1_REG_ADDR) & RTC_CTL1_BIT_2412) tmp->tm_hour = bcd2bin(hour & 0x3F); else tmp->tm_hour = bcd2bin(hour & 0x1F) % 12 + ((hour & 0x20) ? 12 : 0); tmp->tm_mday = bcd2bin (mday & 0x3F); tmp->tm_mon = bcd2bin (mon & 0x1F); tmp->tm_year = bcd2bin (year) + ( bcd2bin (year) >= 70 ? 1900 : 2000); tmp->tm_wday = bcd2bin (wday & 0x07); tmp->tm_yday = 0; tmp->tm_isdst= 0; DEBUGR("Get DATE: %4d-%02d-%02d (wday=%d) TIME: %2d:%02d:%02d\n", tmp->tm_year, tmp->tm_mon, tmp->tm_mday, tmp->tm_wday, tmp->tm_hour, tmp->tm_min, tmp->tm_sec); return rel; } /* * Set the RTC */ static int rx8025_rtc_set(struct udevice *dev, const struct rtc_time *tmp) { /* To work around the read/write cycle issue mentioned * at the top of this file, write all the time registers * in one I2C transaction */ u8 write_op[8]; /* 2412 flag must be set before doing a RTC write, * otherwise the seconds and minute register * will be cleared when the flag is set */ if (rtc_write(dev, RTC_CTL1_REG_ADDR, RTC_CTL1_BIT_2412)) return -EIO; DEBUGR("Set DATE: %4d-%02d-%02d (wday=%d) TIME: %2d:%02d:%02d\n", tmp->tm_year, tmp->tm_mon, tmp->tm_mday, tmp->tm_wday, tmp->tm_hour, tmp->tm_min, tmp->tm_sec); if (tmp->tm_year < 1970 || tmp->tm_year > 2069) printf("WARNING: year should be between 1970 and 2069!\n"); write_op[RTC_SEC_REG_ADDR] = bin2bcd(tmp->tm_sec); write_op[RTC_MIN_REG_ADDR] = bin2bcd(tmp->tm_min); write_op[RTC_HR_REG_ADDR] = bin2bcd(tmp->tm_hour); write_op[RTC_DAY_REG_ADDR] = bin2bcd(tmp->tm_wday); write_op[RTC_DATE_REG_ADDR] = bin2bcd(tmp->tm_mday); write_op[RTC_MON_REG_ADDR] = bin2bcd(tmp->tm_mon); write_op[RTC_YR_REG_ADDR] = bin2bcd(tmp->tm_year % 100); write_op[RTC_OFFSET_REG_ADDR] = 0; return dm_i2c_write(dev, 0, &write_op[0], 8); } /* * Reset the RTC */ static int rx8025_rtc_reset(struct udevice *dev) { uchar buf[16]; uchar ctl2; if (dm_i2c_read(dev, 0, buf, sizeof(buf))) { printf("Error reading from RTC\n"); return -EIO; } ctl2 = rtc_read(RTC_CTL2_REG_ADDR); ctl2 &= ~(RTC_CTL2_BIT_PON | RTC_CTL2_BIT_VDET); if (dev->driver_data == model_rx_8035) ctl2 &= ~(RTC_CTL2_BIT_XST); else ctl2 |= RTC_CTL2_BIT_XST; return rtc_write(dev, RTC_CTL2_REG_ADDR, ctl2); } /* * Helper functions */ static int rtc_write(struct udevice *dev, uchar reg, uchar val) { /* The RX8025/RX8035 uses the top 4 bits of the * 'offset' byte as the start register address, * and the bottom 4 bits as a 'transfer' mode setting * (only applicable for reads) */ u8 offset = (reg << 4); if (dm_i2c_reg_write(dev, offset, val)) { printf("Error writing to RTC\n"); return -EIO; } return 0; } static int rx8025_probe(struct udevice *dev) { uchar buf[16]; int ret = 0; if (i2c_get_chip_offset_len(dev) != 1) ret = i2c_set_chip_offset_len(dev, 1); if (ret) return ret; return dm_i2c_read(dev, 0, buf, sizeof(buf)); } static const struct rtc_ops rx8025_rtc_ops = { .get = rx8025_rtc_get, .set = rx8025_rtc_set, .reset = rx8025_rtc_reset, }; static const struct udevice_id rx8025_rtc_ids[] = { { .compatible = "epson,rx8025", .data = model_rx_8025 }, { .compatible = "epson,rx8035", .data = model_rx_8035 }, { } }; U_BOOT_DRIVER(rx8025_rtc) = { .name = "rx8025_rtc", .id = UCLASS_RTC, .probe = rx8025_probe, .of_match = rx8025_rtc_ids, .ops = &rx8025_rtc_ops, };