/* * Micro Crystal RV-3029 rtc class driver * * Author: Gregory Hermant * Michael Buesch * * based on previously existing rtc class drivers * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License version 2 as * published by the Free Software Foundation. * * NOTE: Currently this driver only supports the bare minimum for read * and write the RTC and alarms. The extra features provided by this chip * (trickle charger, eeprom, T° compensation) are unavailable. */ #include #include #include #include #include #include /* Register map */ /* 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 #define RV3029_WATCH_SECTION_LEN 0x07 /* alarm section */ #define RV3029_A_SC 0x10 #define RV3029_A_MN 0x11 #define RV3029_A_HR 0x12 #define RV3029_A_DT 0x13 #define RV3029_A_DW 0x14 #define RV3029_A_MO 0x15 #define RV3029_A_YR 0x16 #define RV3029_ALARM_SECTION_LEN 0x07 /* timer section */ #define RV3029_TIMER_LOW 0x18 #define RV3029_TIMER_HIGH 0x19 /* temperature section */ #define RV3029_TEMP_PAGE 0x20 /* eeprom data section */ #define RV3029_E2P_EEDATA1 0x28 #define RV3029_E2P_EEDATA2 0x29 #define RV3029_E2PDATA_SECTION_LEN 0x02 /* eeprom control section */ #define RV3029_CONTROL_E2P_EECTRL 0x30 #define RV3029_EECTRL_THP BIT(0) /* temp scan interval */ #define RV3029_EECTRL_THE BIT(1) /* thermometer enable */ #define RV3029_EECTRL_FD0 BIT(2) /* CLKOUT */ #define RV3029_EECTRL_FD1 BIT(3) /* CLKOUT */ #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 #define RV3029_CONTROL_E2P_XOFFS 0x31 /* XTAL offset */ #define RV3029_CONTROL_E2P_XOFFS_SIGN BIT(7) /* Sign: 1->pos, 0->neg */ #define RV3029_CONTROL_E2P_QCOEF 0x32 /* XTAL temp drift coef */ #define RV3029_CONTROL_E2P_TURNOVER 0x33 /* XTAL turnover temp (in *C) */ #define RV3029_CONTROL_E2P_TOV_MASK 0x3F /* XTAL turnover temp mask */ /* user ram section */ #define RV3029_USR1_RAM_PAGE 0x38 #define RV3029_USR1_SECTION_LEN 0x04 #define RV3029_USR2_RAM_PAGE 0x3C #define RV3029_USR2_SECTION_LEN 0x04 static int rv3029_i2c_read_regs(struct i2c_client *client, u8 reg, u8 *buf, unsigned len) { int ret; if ((reg > RV3029_USR1_RAM_PAGE + 7) || (reg + len > RV3029_USR1_RAM_PAGE + 8)) return -EINVAL; ret = i2c_smbus_read_i2c_block_data(client, reg, len, buf); if (ret < 0) return ret; if (ret < len) return -EIO; return 0; } static int rv3029_i2c_write_regs(struct i2c_client *client, u8 reg, u8 const buf[], unsigned len) { if ((reg > RV3029_USR1_RAM_PAGE + 7) || (reg + len > RV3029_USR1_RAM_PAGE + 8)) return -EINVAL; return i2c_smbus_write_i2c_block_data(client, reg, len, buf); } static int rv3029_i2c_update_bits(struct i2c_client *client, u8 reg, u8 mask, u8 set) { u8 buf; int ret; ret = rv3029_i2c_read_regs(client, reg, &buf, 1); if (ret < 0) return ret; buf &= ~mask; buf |= set & mask; ret = rv3029_i2c_write_regs(client, reg, &buf, 1); if (ret < 0) return ret; return 0; } static int rv3029_i2c_get_sr(struct i2c_client *client, u8 *buf) { int ret = rv3029_i2c_read_regs(client, RV3029_STATUS, buf, 1); if (ret < 0) return -EIO; dev_dbg(&client->dev, "status = 0x%.2x (%d)\n", buf[0], buf[0]); return 0; } static int rv3029_i2c_set_sr(struct i2c_client *client, u8 val) { u8 buf[1]; int sr; buf[0] = val; sr = rv3029_i2c_write_regs(client, RV3029_STATUS, buf, 1); dev_dbg(&client->dev, "status = 0x%.2x (%d)\n", buf[0], buf[0]); if (sr < 0) return -EIO; return 0; } static int rv3029_eeprom_busywait(struct i2c_client *client) { int i, ret; u8 sr; for (i = 100; i > 0; i--) { ret = rv3029_i2c_get_sr(client, &sr); if (ret < 0) break; if (!(sr & RV3029_STATUS_EEBUSY)) break; usleep_range(1000, 10000); } if (i <= 0) { dev_err(&client->dev, "EEPROM busy wait timeout.\n"); return -ETIMEDOUT; } return ret; } static int rv3029_eeprom_exit(struct i2c_client *client) { /* Re-enable eeprom refresh */ return rv3029_i2c_update_bits(client, RV3029_ONOFF_CTRL, RV3029_ONOFF_CTRL_EERE, RV3029_ONOFF_CTRL_EERE); } static int rv3029_eeprom_enter(struct i2c_client *client) { int ret; u8 sr; /* Check whether we are in the allowed voltage range. */ ret = rv3029_i2c_get_sr(client, &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_i2c_set_sr(client, sr); if (ret < 0) return ret; usleep_range(1000, 10000); ret = rv3029_i2c_get_sr(client, &sr); if (ret < 0) return ret; if (sr & (RV3029_STATUS_VLOW1 | RV3029_STATUS_VLOW2)) { dev_err(&client->dev, "Supply voltage is too low to safely access the EEPROM.\n"); return -ENODEV; } } /* Disable eeprom refresh. */ ret = rv3029_i2c_update_bits(client, 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(client); if (ret < 0) rv3029_eeprom_exit(client); return ret; } static int rv3029_eeprom_read(struct i2c_client *client, u8 reg, u8 buf[], size_t len) { int ret, err; err = rv3029_eeprom_enter(client); if (err < 0) return err; ret = rv3029_i2c_read_regs(client, reg, buf, len); err = rv3029_eeprom_exit(client); if (err < 0) return err; return ret; } static int rv3029_eeprom_write(struct i2c_client *client, u8 reg, u8 const buf[], size_t len) { int ret, err; size_t i; u8 tmp; err = rv3029_eeprom_enter(client); if (err < 0) return err; for (i = 0; i < len; i++, reg++) { ret = rv3029_i2c_read_regs(client, reg, &tmp, 1); if (ret < 0) break; if (tmp != buf[i]) { ret = rv3029_i2c_write_regs(client, reg, &buf[i], 1); if (ret < 0) break; } ret = rv3029_eeprom_busywait(client); if (ret < 0) break; } err = rv3029_eeprom_exit(client); if (err < 0) return err; return ret; } static int rv3029_i2c_read_time(struct i2c_client *client, struct rtc_time *tm) { u8 buf[1]; int ret; u8 regs[RV3029_WATCH_SECTION_LEN] = { 0, }; ret = rv3029_i2c_get_sr(client, buf); if (ret < 0) { dev_err(&client->dev, "%s: reading SR failed\n", __func__); return -EIO; } ret = rv3029_i2c_read_regs(client, RV3029_W_SEC, regs, RV3029_WATCH_SECTION_LEN); if (ret < 0) { dev_err(&client->dev, "%s: reading RTC section failed\n", __func__); return ret; } 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; tm->tm_year = bcd2bin(regs[RV3029_W_YEARS-RV3029_W_SEC]) + 100; tm->tm_wday = bcd2bin(regs[RV3029_W_DAYS-RV3029_W_SEC]) - 1; return 0; } static int rv3029_rtc_read_time(struct device *dev, struct rtc_time *tm) { return rv3029_i2c_read_time(to_i2c_client(dev), tm); } static int rv3029_i2c_read_alarm(struct i2c_client *client, struct rtc_wkalrm *alarm) { struct rtc_time *const tm = &alarm->time; int ret; u8 regs[8]; ret = rv3029_i2c_get_sr(client, regs); if (ret < 0) { dev_err(&client->dev, "%s: reading SR failed\n", __func__); return -EIO; } ret = rv3029_i2c_read_regs(client, RV3029_A_SC, regs, RV3029_ALARM_SECTION_LEN); if (ret < 0) { dev_err(&client->dev, "%s: reading alarm section failed\n", __func__); return ret; } tm->tm_sec = bcd2bin(regs[RV3029_A_SC-RV3029_A_SC] & 0x7f); tm->tm_min = bcd2bin(regs[RV3029_A_MN-RV3029_A_SC] & 0x7f); tm->tm_hour = bcd2bin(regs[RV3029_A_HR-RV3029_A_SC] & 0x3f); tm->tm_mday = bcd2bin(regs[RV3029_A_DT-RV3029_A_SC] & 0x3f); tm->tm_mon = bcd2bin(regs[RV3029_A_MO-RV3029_A_SC] & 0x1f) - 1; tm->tm_year = bcd2bin(regs[RV3029_A_YR-RV3029_A_SC] & 0x7f) + 100; tm->tm_wday = bcd2bin(regs[RV3029_A_DW-RV3029_A_SC] & 0x07) - 1; return 0; } static int rv3029_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alarm) { return rv3029_i2c_read_alarm(to_i2c_client(dev), alarm); } static int rv3029_rtc_i2c_alarm_set_irq(struct i2c_client *client, int enable) { int ret; /* enable/disable AIE irq */ ret = rv3029_i2c_update_bits(client, RV3029_IRQ_CTRL, RV3029_IRQ_CTRL_AIE, (enable ? RV3029_IRQ_CTRL_AIE : 0)); if (ret < 0) { dev_err(&client->dev, "can't update INT reg\n"); return ret; } return 0; } static int rv3029_rtc_i2c_set_alarm(struct i2c_client *client, struct rtc_wkalrm *alarm) { struct rtc_time *const tm = &alarm->time; int ret; u8 regs[8]; /* * The clock has an 8 bit wide bcd-coded register (they never learn) * for the year. tm_year is an offset from 1900 and we are interested * in the 2000-2099 range, so any value less than 100 is invalid. */ if (tm->tm_year < 100) return -EINVAL; ret = rv3029_i2c_get_sr(client, regs); if (ret < 0) { dev_err(&client->dev, "%s: reading SR failed\n", __func__); return -EIO; } regs[RV3029_A_SC-RV3029_A_SC] = bin2bcd(tm->tm_sec & 0x7f); regs[RV3029_A_MN-RV3029_A_SC] = bin2bcd(tm->tm_min & 0x7f); regs[RV3029_A_HR-RV3029_A_SC] = bin2bcd(tm->tm_hour & 0x3f); regs[RV3029_A_DT-RV3029_A_SC] = bin2bcd(tm->tm_mday & 0x3f); regs[RV3029_A_MO-RV3029_A_SC] = bin2bcd((tm->tm_mon & 0x1f) - 1); regs[RV3029_A_DW-RV3029_A_SC] = bin2bcd((tm->tm_wday & 7) - 1); regs[RV3029_A_YR-RV3029_A_SC] = bin2bcd((tm->tm_year & 0x7f) - 100); ret = rv3029_i2c_write_regs(client, RV3029_A_SC, regs, RV3029_ALARM_SECTION_LEN); if (ret < 0) return ret; if (alarm->enabled) { /* clear AF flag */ ret = rv3029_i2c_update_bits(client, RV3029_IRQ_FLAGS, RV3029_IRQ_FLAGS_AF, 0); if (ret < 0) { dev_err(&client->dev, "can't clear alarm flag\n"); return ret; } /* enable AIE irq */ ret = rv3029_rtc_i2c_alarm_set_irq(client, 1); if (ret) return ret; dev_dbg(&client->dev, "alarm IRQ armed\n"); } else { /* disable AIE irq */ ret = rv3029_rtc_i2c_alarm_set_irq(client, 0); if (ret) return ret; dev_dbg(&client->dev, "alarm IRQ disabled\n"); } return 0; } static int rv3029_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alarm) { return rv3029_rtc_i2c_set_alarm(to_i2c_client(dev), alarm); } static int rv3029_i2c_set_time(struct i2c_client *client, struct rtc_time const *tm) { u8 regs[8]; int ret; /* * The clock has an 8 bit wide bcd-coded register (they never learn) * for the year. tm_year is an offset from 1900 and we are interested * in the 2000-2099 range, so any value less than 100 is invalid. */ if (tm->tm_year < 100) 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 & 7)+1); regs[RV3029_W_YEARS-RV3029_W_SEC] = bin2bcd(tm->tm_year - 100); ret = rv3029_i2c_write_regs(client, RV3029_W_SEC, regs, RV3029_WATCH_SECTION_LEN); if (ret < 0) return ret; ret = rv3029_i2c_get_sr(client, regs); if (ret < 0) { dev_err(&client->dev, "%s: reading SR failed\n", __func__); return ret; } /* clear PON bit */ ret = rv3029_i2c_set_sr(client, (regs[0] & ~RV3029_STATUS_PON)); if (ret < 0) { dev_err(&client->dev, "%s: reading SR failed\n", __func__); return ret; } return 0; } static int rv3029_rtc_set_time(struct device *dev, struct rtc_time *tm) { return rv3029_i2c_set_time(to_i2c_client(dev), tm); } static const struct rtc_class_ops rv3029_rtc_ops = { .read_time = rv3029_rtc_read_time, .set_time = rv3029_rtc_set_time, .read_alarm = rv3029_rtc_read_alarm, .set_alarm = rv3029_rtc_set_alarm, }; static struct i2c_device_id rv3029_id[] = { { "rv3029", 0 }, { "rv3029c2", 0 }, { } }; MODULE_DEVICE_TABLE(i2c, rv3029_id); static int rv3029_probe(struct i2c_client *client, const struct i2c_device_id *id) { struct rtc_device *rtc; int rc = 0; u8 buf[1]; if (!i2c_check_functionality(client->adapter, I2C_FUNC_SMBUS_EMUL)) return -ENODEV; rc = rv3029_i2c_get_sr(client, buf); if (rc < 0) { dev_err(&client->dev, "reading status failed\n"); return rc; } rtc = devm_rtc_device_register(&client->dev, client->name, &rv3029_rtc_ops, THIS_MODULE); if (IS_ERR(rtc)) return PTR_ERR(rtc); i2c_set_clientdata(client, rtc); return 0; } static struct i2c_driver rv3029_driver = { .driver = { .name = "rtc-rv3029c2", }, .probe = rv3029_probe, .id_table = rv3029_id, }; module_i2c_driver(rv3029_driver); MODULE_AUTHOR("Gregory Hermant "); MODULE_AUTHOR("Michael Buesch "); MODULE_DESCRIPTION("Micro Crystal RV3029 RTC driver"); MODULE_LICENSE("GPL");