// SPDX-License-Identifier: GPL-2.0+ /* * (C) Copyright 2018 Theobroma Systems Design und Consulting GmbH * * Based on a the Linux rtc-rv3029c2.c driver written by: * Gregory Hermant <gregory.hermant@calao-systems.com> * Michael Buesch <m@bues.ch> */ #include <common.h> #include <command.h> #include <dm.h> #include <eeprom.h> #include <i2c.h> #include <log.h> #include <rtc.h> #include <dm/device_compat.h> #include <linux/bitops.h> #include <linux/delay.h> #define RTC_RV3029_PAGE_LEN 7 /* control section */ #define RV3029_ONOFF_CTRL 0x00 #define RV3029_ONOFF_CTRL_WE BIT(0) #define RV3029_ONOFF_CTRL_TE BIT(1) #define RV3029_ONOFF_CTRL_TAR BIT(2) #define RV3029_ONOFF_CTRL_EERE BIT(3) #define RV3029_ONOFF_CTRL_SRON BIT(4) #define RV3029_ONOFF_CTRL_TD0 BIT(5) #define RV3029_ONOFF_CTRL_TD1 BIT(6) #define RV3029_ONOFF_CTRL_CLKINT BIT(7) #define RV3029_IRQ_CTRL 0x01 #define RV3029_IRQ_CTRL_AIE BIT(0) #define RV3029_IRQ_CTRL_TIE BIT(1) #define RV3029_IRQ_CTRL_V1IE BIT(2) #define RV3029_IRQ_CTRL_V2IE BIT(3) #define RV3029_IRQ_CTRL_SRIE BIT(4) #define RV3029_IRQ_FLAGS 0x02 #define RV3029_IRQ_FLAGS_AF BIT(0) #define RV3029_IRQ_FLAGS_TF BIT(1) #define RV3029_IRQ_FLAGS_V1IF BIT(2) #define RV3029_IRQ_FLAGS_V2IF BIT(3) #define RV3029_IRQ_FLAGS_SRF BIT(4) #define RV3029_STATUS 0x03 #define RV3029_STATUS_VLOW1 BIT(2) #define RV3029_STATUS_VLOW2 BIT(3) #define RV3029_STATUS_SR BIT(4) #define RV3029_STATUS_PON BIT(5) #define RV3029_STATUS_EEBUSY BIT(7) #define RV3029_RST_CTRL 0x04 #define RV3029_RST_CTRL_SYSR BIT(4) #define RV3029_CONTROL_SECTION_LEN 0x05 /* watch section */ #define RV3029_W_SEC 0x08 #define RV3029_W_MINUTES 0x09 #define RV3029_W_HOURS 0x0A #define RV3029_REG_HR_12_24 BIT(6) /* 24h/12h mode */ #define RV3029_REG_HR_PM BIT(5) /* PM/AM bit in 12h mode */ #define RV3029_W_DATE 0x0B #define RV3029_W_DAYS 0x0C #define RV3029_W_MONTHS 0x0D #define RV3029_W_YEARS 0x0E /* eeprom control section */ #define RV3029_CONTROL_E2P_EECTRL 0x30 #define RV3029_TRICKLE_1K BIT(4) /* 1.5K resistance */ #define RV3029_TRICKLE_5K BIT(5) /* 5K resistance */ #define RV3029_TRICKLE_20K BIT(6) /* 20K resistance */ #define RV3029_TRICKLE_80K BIT(7) /* 80K resistance */ #define RV3029_TRICKLE_MASK (RV3029_TRICKLE_1K |\ RV3029_TRICKLE_5K |\ RV3029_TRICKLE_20K |\ RV3029_TRICKLE_80K) #define RV3029_TRICKLE_SHIFT 4 static int rv3029_rtc_get(struct udevice *dev, struct rtc_time *tm) { u8 regs[RTC_RV3029_PAGE_LEN]; int ret; ret = dm_i2c_read(dev, RV3029_W_SEC, regs, sizeof(regs)); if (ret < 0) { printf("%s: error reading RTC: %x\n", __func__, ret); return -EIO; } tm->tm_sec = bcd2bin(regs[RV3029_W_SEC - RV3029_W_SEC]); tm->tm_min = bcd2bin(regs[RV3029_W_MINUTES - RV3029_W_SEC]); /* HR field has a more complex interpretation */ { const u8 _hr = regs[RV3029_W_HOURS - RV3029_W_SEC]; if (_hr & RV3029_REG_HR_12_24) { /* 12h format */ tm->tm_hour = bcd2bin(_hr & 0x1f); if (_hr & RV3029_REG_HR_PM) /* PM flag set */ tm->tm_hour += 12; } else { /* 24h format */ tm->tm_hour = bcd2bin(_hr & 0x3f); } } tm->tm_mday = bcd2bin(regs[RV3029_W_DATE - RV3029_W_SEC]); tm->tm_mon = bcd2bin(regs[RV3029_W_MONTHS - RV3029_W_SEC]) - 1; /* RTC supports only years > 1999 */ tm->tm_year = bcd2bin(regs[RV3029_W_YEARS - RV3029_W_SEC]) + 2000; tm->tm_wday = bcd2bin(regs[RV3029_W_DAYS - RV3029_W_SEC]) - 1; tm->tm_yday = 0; tm->tm_isdst = 0; debug("%s: %4d-%02d-%02d (wday=%d) %2d:%02d:%02d\n", __func__, tm->tm_year, tm->tm_mon, tm->tm_mday, tm->tm_wday, tm->tm_hour, tm->tm_min, tm->tm_sec); return 0; } static int rv3029_rtc_set(struct udevice *dev, const struct rtc_time *tm) { u8 regs[RTC_RV3029_PAGE_LEN]; debug("%s: %4d-%02d-%02d (wday=%d( %2d:%02d:%02d\n", __func__, tm->tm_year, tm->tm_mon, tm->tm_mday, tm->tm_wday, tm->tm_hour, tm->tm_min, tm->tm_sec); if (tm->tm_year < 2000) { printf("%s: year %d (before 2000) not supported\n", __func__, tm->tm_year); return -EINVAL; } regs[RV3029_W_SEC - RV3029_W_SEC] = bin2bcd(tm->tm_sec); regs[RV3029_W_MINUTES - RV3029_W_SEC] = bin2bcd(tm->tm_min); regs[RV3029_W_HOURS - RV3029_W_SEC] = bin2bcd(tm->tm_hour); regs[RV3029_W_DATE - RV3029_W_SEC] = bin2bcd(tm->tm_mday); regs[RV3029_W_MONTHS - RV3029_W_SEC] = bin2bcd(tm->tm_mon + 1); regs[RV3029_W_DAYS - RV3029_W_SEC] = bin2bcd(tm->tm_wday + 1) & 0x7; regs[RV3029_W_YEARS - RV3029_W_SEC] = bin2bcd(tm->tm_year - 2000); return dm_i2c_write(dev, RV3029_W_SEC, regs, sizeof(regs)); } static int rv3029_rtc_reset(struct udevice *dev) { u8 ctrl = RV3029_RST_CTRL_SYSR; unsigned long start; const unsigned long timeout_ms = 10000; int ret; /* trigger the system-reset */ ret = dm_i2c_write(dev, RV3029_RST_CTRL, &ctrl, 1); if (ret < 0) return -EIO; /* wait for the system-reset to complete */ start = get_timer(0); do { if (get_timer(start) > timeout_ms) return -ETIMEDOUT; ret = dm_i2c_read(dev, RV3029_RST_CTRL, &ctrl, 1); if (ret < 0) return -EIO; } while (ctrl & RV3029_RST_CTRL_SYSR); return 0; } static int rv3029_rtc_read8(struct udevice *dev, unsigned int reg) { u8 data; int ret; ret = dm_i2c_read(dev, reg, &data, sizeof(data)); return ret < 0 ? ret : data; } static int rv3029_rtc_write8(struct udevice *dev, unsigned int reg, int val) { u8 data = val; return dm_i2c_write(dev, reg, &data, 1); } #if defined(OF_CONTROL) static int rv3029_get_sr(struct udevice *dev, u8 *buf) { int ret = dm_i2c_read(dev, RV3029_STATUS, buf, 1); if (ret < 0) return -EIO; dev_dbg(dev, "status = 0x%.2x (%d)\n", buf[0], buf[0]); return 0; } static int rv3029_set_sr(struct udevice *dev, u8 val) { int ret; ret = dm_i2c_read(dev, RV3029_STATUS, &val, 1); if (ret < 0) return -EIO; dev_dbg(dev, "status = 0x%.2x (%d)\n", val, val); return 0; } static int rv3029_eeprom_busywait(struct udevice *dev) { int i, ret; u8 sr; for (i = 100; i > 0; i--) { ret = rv3029_get_sr(dev, &sr); if (ret < 0) break; if (!(sr & RV3029_STATUS_EEBUSY)) break; udelay(10000); } if (i <= 0) { dev_err(dev, "EEPROM busy wait timeout.\n"); return -ETIMEDOUT; } return ret; } static int rv3029_update_bits(struct udevice *dev, u8 reg, u8 mask, u8 set) { u8 buf; int ret; ret = dm_i2c_read(dev, reg, &buf, 1); if (ret < 0) return ret; if ((buf & mask) == (set && mask)) return 0; buf = (buf & ~mask) | (set & mask); ret = dm_i2c_read(dev, reg, &buf, 1); if (ret < 0) return ret; return 0; } static int rv3029_eeprom_exit(struct udevice *dev) { /* Re-enable eeprom refresh */ return rv3029_update_bits(dev, RV3029_ONOFF_CTRL, RV3029_ONOFF_CTRL_EERE, RV3029_ONOFF_CTRL_EERE); } static int rv3029_eeprom_enter(struct udevice *dev) { int ret; u8 sr; /* Check whether we are in the allowed voltage range. */ ret = rv3029_get_sr(dev, &sr); if (ret < 0) return ret; if (sr & (RV3029_STATUS_VLOW1 | RV3029_STATUS_VLOW2)) { /* We clear the bits and retry once just in case * we had a brown out in early startup. */ sr &= ~RV3029_STATUS_VLOW1; sr &= ~RV3029_STATUS_VLOW2; ret = rv3029_set_sr(dev, sr); if (ret < 0) return ret; udelay(10000); ret = rv3029_get_sr(dev, &sr); if (ret < 0) return ret; if (sr & (RV3029_STATUS_VLOW1 | RV3029_STATUS_VLOW2)) { dev_err(dev, "Supply voltage is too low to safely access the EEPROM.\n"); return -ENODEV; } } /* Disable eeprom refresh. */ ret = rv3029_update_bits(dev, RV3029_ONOFF_CTRL, RV3029_ONOFF_CTRL_EERE, 0); if (ret < 0) return ret; /* Wait for any previous eeprom accesses to finish. */ ret = rv3029_eeprom_busywait(dev); if (ret < 0) rv3029_eeprom_exit(dev); return ret; } static int rv3029_eeprom_read(struct udevice *dev, u8 reg, u8 buf[], size_t len) { int ret, err; err = rv3029_eeprom_enter(dev); if (err < 0) return err; ret = dm_i2c_read(dev, reg, buf, len); err = rv3029_eeprom_exit(dev); if (err < 0) return err; return ret; } static int rv3029_eeprom_write(struct udevice *dev, u8 reg, u8 const buf[], size_t len) { int ret; size_t i; u8 tmp; ret = rv3029_eeprom_enter(dev); if (ret < 0) return ret; for (i = 0; i < len; i++, reg++) { ret = dm_i2c_read(dev, reg, &tmp, 1); if (ret < 0) break; if (tmp != buf[i]) { ret = dm_i2c_write(dev, reg, &buf[i], 1); if (ret < 0) break; } ret = rv3029_eeprom_busywait(dev); if (ret < 0) break; } ret = rv3029_eeprom_exit(dev); if (ret < 0) return ret; return 0; } static int rv3029_eeprom_update_bits(struct udevice *dev, u8 reg, u8 mask, u8 set) { u8 buf; int ret; ret = rv3029_eeprom_read(dev, reg, &buf, 1); if (ret < 0) return ret; /* * If the EEPROM already reads the correct bitpattern, we don't need * to update it. */ if ((buf & mask) == (set & mask)) return 0; buf = (buf & ~mask) | (set & mask); ret = rv3029_eeprom_write(dev, reg, &buf, 1); if (ret < 0) return ret; return 0; } static void rv3029_trickle_config(struct udevice *dev) { static const struct rv3029_trickle_tab_elem { u32 r; /* resistance in ohms */ u8 conf; /* trickle config bits */ } rv3029_trickle_tab[] = { { .r = 1076, .conf = RV3029_TRICKLE_1K | RV3029_TRICKLE_5K | RV3029_TRICKLE_20K | RV3029_TRICKLE_80K, }, { .r = 1091, .conf = RV3029_TRICKLE_1K | RV3029_TRICKLE_5K | RV3029_TRICKLE_20K, }, { .r = 1137, .conf = RV3029_TRICKLE_1K | RV3029_TRICKLE_5K | RV3029_TRICKLE_80K, }, { .r = 1154, .conf = RV3029_TRICKLE_1K | RV3029_TRICKLE_5K, }, { .r = 1371, .conf = RV3029_TRICKLE_1K | RV3029_TRICKLE_20K | RV3029_TRICKLE_80K, }, { .r = 1395, .conf = RV3029_TRICKLE_1K | RV3029_TRICKLE_20K, }, { .r = 1472, .conf = RV3029_TRICKLE_1K | RV3029_TRICKLE_80K, }, { .r = 1500, .conf = RV3029_TRICKLE_1K, }, { .r = 3810, .conf = RV3029_TRICKLE_5K | RV3029_TRICKLE_20K | RV3029_TRICKLE_80K, }, { .r = 4000, .conf = RV3029_TRICKLE_5K | RV3029_TRICKLE_20K, }, { .r = 4706, .conf = RV3029_TRICKLE_5K | RV3029_TRICKLE_80K, }, { .r = 5000, .conf = RV3029_TRICKLE_5K, }, { .r = 16000, .conf = RV3029_TRICKLE_20K | RV3029_TRICKLE_80K, }, { .r = 20000, .conf = RV3029_TRICKLE_20K, }, { .r = 80000, .conf = RV3029_TRICKLE_80K, }, }; int err; u32 ohms; u8 trickle_set_bits = 0; /* Configure the trickle charger. */ err = dev_read_u32(dev, "trickle-resistor-ohms", &ohms); if (!err) { /* Find trickle-charger config */ for (int i = 0; i < ARRAY_SIZE(rv3029_trickle_tab); i++) if (rv3029_trickle_tab[i].r >= ohms) { dev_dbg(dev, "trickle charger at %d ohms\n", rv3029_trickle_tab[i].r); trickle_set_bits = rv3029_trickle_tab[i].conf; break; } } dev_dbg(dev, "trickle charger config 0x%x\n", trickle_set_bits); err = rv3029_eeprom_update_bits(dev, RV3029_CONTROL_E2P_EECTRL, RV3029_TRICKLE_MASK, trickle_set_bits); if (err < 0) dev_dbg(dev, "failed to update trickle charger\n"); } #else static inline void rv3029_trickle_config(struct udevice *dev) { } #endif static int rv3029_probe(struct udevice *dev) { i2c_set_chip_flags(dev, DM_I2C_CHIP_RD_ADDRESS | DM_I2C_CHIP_WR_ADDRESS); rv3029_trickle_config(dev); return 0; } static const struct rtc_ops rv3029_rtc_ops = { .get = rv3029_rtc_get, .set = rv3029_rtc_set, .read8 = rv3029_rtc_read8, .write8 = rv3029_rtc_write8, .reset = rv3029_rtc_reset, }; static const struct udevice_id rv3029_rtc_ids[] = { { .compatible = "mc,rv3029" }, { .compatible = "mc,rv3029c2" }, { } }; U_BOOT_DRIVER(rtc_rv3029) = { .name = "rtc-rv3029", .id = UCLASS_RTC, .probe = rv3029_probe, .of_match = rv3029_rtc_ids, .ops = &rv3029_rtc_ops, };