/* * A driver for the I2C members of the Abracon AB x8xx RTC family, * and compatible: AB 1805 and AB 0805 * * Copyright 2014-2015 Macq S.A. * * Author: Philippe De Muyter * Author: Alexandre Belloni * * 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. * */ #include #include #include #include #define ABX8XX_REG_HTH 0x00 #define ABX8XX_REG_SC 0x01 #define ABX8XX_REG_MN 0x02 #define ABX8XX_REG_HR 0x03 #define ABX8XX_REG_DA 0x04 #define ABX8XX_REG_MO 0x05 #define ABX8XX_REG_YR 0x06 #define ABX8XX_REG_WD 0x07 #define ABX8XX_REG_AHTH 0x08 #define ABX8XX_REG_ASC 0x09 #define ABX8XX_REG_AMN 0x0a #define ABX8XX_REG_AHR 0x0b #define ABX8XX_REG_ADA 0x0c #define ABX8XX_REG_AMO 0x0d #define ABX8XX_REG_AWD 0x0e #define ABX8XX_REG_STATUS 0x0f #define ABX8XX_STATUS_AF BIT(2) #define ABX8XX_REG_CTRL1 0x10 #define ABX8XX_CTRL_WRITE BIT(0) #define ABX8XX_CTRL_ARST BIT(2) #define ABX8XX_CTRL_12_24 BIT(6) #define ABX8XX_REG_IRQ 0x12 #define ABX8XX_IRQ_AIE BIT(2) #define ABX8XX_IRQ_IM_1_4 (0x3 << 5) #define ABX8XX_REG_CD_TIMER_CTL 0x18 #define ABX8XX_REG_OSC 0x1c #define ABX8XX_OSC_FOS BIT(3) #define ABX8XX_OSC_BOS BIT(4) #define ABX8XX_OSC_ACAL_512 BIT(5) #define ABX8XX_OSC_ACAL_1024 BIT(6) #define ABX8XX_OSC_OSEL BIT(7) #define ABX8XX_REG_OSS 0x1d #define ABX8XX_OSS_OF BIT(1) #define ABX8XX_OSS_OMODE BIT(4) #define ABX8XX_REG_CFG_KEY 0x1f #define ABX8XX_CFG_KEY_OSC 0xa1 #define ABX8XX_CFG_KEY_MISC 0x9d #define ABX8XX_REG_ID0 0x28 #define ABX8XX_REG_TRICKLE 0x20 #define ABX8XX_TRICKLE_CHARGE_ENABLE 0xa0 #define ABX8XX_TRICKLE_STANDARD_DIODE 0x8 #define ABX8XX_TRICKLE_SCHOTTKY_DIODE 0x4 static u8 trickle_resistors[] = {0, 3, 6, 11}; enum abx80x_chip {AB0801, AB0803, AB0804, AB0805, AB1801, AB1803, AB1804, AB1805, ABX80X}; struct abx80x_cap { u16 pn; bool has_tc; }; static struct abx80x_cap abx80x_caps[] = { [AB0801] = {.pn = 0x0801}, [AB0803] = {.pn = 0x0803}, [AB0804] = {.pn = 0x0804, .has_tc = true}, [AB0805] = {.pn = 0x0805, .has_tc = true}, [AB1801] = {.pn = 0x1801}, [AB1803] = {.pn = 0x1803}, [AB1804] = {.pn = 0x1804, .has_tc = true}, [AB1805] = {.pn = 0x1805, .has_tc = true}, [ABX80X] = {.pn = 0} }; static int abx80x_is_rc_mode(struct i2c_client *client) { int flags = 0; flags = i2c_smbus_read_byte_data(client, ABX8XX_REG_OSS); if (flags < 0) { dev_err(&client->dev, "Failed to read autocalibration attribute\n"); return flags; } return (flags & ABX8XX_OSS_OMODE) ? 1 : 0; } static int abx80x_enable_trickle_charger(struct i2c_client *client, u8 trickle_cfg) { int err; /* * Write the configuration key register to enable access to the Trickle * register */ err = i2c_smbus_write_byte_data(client, ABX8XX_REG_CFG_KEY, ABX8XX_CFG_KEY_MISC); if (err < 0) { dev_err(&client->dev, "Unable to write configuration key\n"); return -EIO; } err = i2c_smbus_write_byte_data(client, ABX8XX_REG_TRICKLE, ABX8XX_TRICKLE_CHARGE_ENABLE | trickle_cfg); if (err < 0) { dev_err(&client->dev, "Unable to write trickle register\n"); return -EIO; } return 0; } static int abx80x_rtc_read_time(struct device *dev, struct rtc_time *tm) { struct i2c_client *client = to_i2c_client(dev); unsigned char buf[8]; int err, flags, rc_mode = 0; /* Read the Oscillator Failure only in XT mode */ rc_mode = abx80x_is_rc_mode(client); if (rc_mode < 0) return rc_mode; if (!rc_mode) { flags = i2c_smbus_read_byte_data(client, ABX8XX_REG_OSS); if (flags < 0) return flags; if (flags & ABX8XX_OSS_OF) { dev_err(dev, "Oscillator failure, data is invalid.\n"); return -EINVAL; } } err = i2c_smbus_read_i2c_block_data(client, ABX8XX_REG_HTH, sizeof(buf), buf); if (err < 0) { dev_err(&client->dev, "Unable to read date\n"); return -EIO; } tm->tm_sec = bcd2bin(buf[ABX8XX_REG_SC] & 0x7F); tm->tm_min = bcd2bin(buf[ABX8XX_REG_MN] & 0x7F); tm->tm_hour = bcd2bin(buf[ABX8XX_REG_HR] & 0x3F); tm->tm_wday = buf[ABX8XX_REG_WD] & 0x7; tm->tm_mday = bcd2bin(buf[ABX8XX_REG_DA] & 0x3F); tm->tm_mon = bcd2bin(buf[ABX8XX_REG_MO] & 0x1F) - 1; tm->tm_year = bcd2bin(buf[ABX8XX_REG_YR]) + 100; err = rtc_valid_tm(tm); if (err < 0) dev_err(&client->dev, "retrieved date/time is not valid.\n"); return err; } static int abx80x_rtc_set_time(struct device *dev, struct rtc_time *tm) { struct i2c_client *client = to_i2c_client(dev); unsigned char buf[8]; int err, flags; if (tm->tm_year < 100) return -EINVAL; buf[ABX8XX_REG_HTH] = 0; buf[ABX8XX_REG_SC] = bin2bcd(tm->tm_sec); buf[ABX8XX_REG_MN] = bin2bcd(tm->tm_min); buf[ABX8XX_REG_HR] = bin2bcd(tm->tm_hour); buf[ABX8XX_REG_DA] = bin2bcd(tm->tm_mday); buf[ABX8XX_REG_MO] = bin2bcd(tm->tm_mon + 1); buf[ABX8XX_REG_YR] = bin2bcd(tm->tm_year - 100); buf[ABX8XX_REG_WD] = tm->tm_wday; err = i2c_smbus_write_i2c_block_data(client, ABX8XX_REG_HTH, sizeof(buf), buf); if (err < 0) { dev_err(&client->dev, "Unable to write to date registers\n"); return -EIO; } /* Clear the OF bit of Oscillator Status Register */ flags = i2c_smbus_read_byte_data(client, ABX8XX_REG_OSS); if (flags < 0) return flags; err = i2c_smbus_write_byte_data(client, ABX8XX_REG_OSS, flags & ~ABX8XX_OSS_OF); if (err < 0) { dev_err(&client->dev, "Unable to write oscillator status register\n"); return err; } return 0; } static irqreturn_t abx80x_handle_irq(int irq, void *dev_id) { struct i2c_client *client = dev_id; struct rtc_device *rtc = i2c_get_clientdata(client); int status; status = i2c_smbus_read_byte_data(client, ABX8XX_REG_STATUS); if (status < 0) return IRQ_NONE; if (status & ABX8XX_STATUS_AF) rtc_update_irq(rtc, 1, RTC_AF | RTC_IRQF); i2c_smbus_write_byte_data(client, ABX8XX_REG_STATUS, 0); return IRQ_HANDLED; } static int abx80x_read_alarm(struct device *dev, struct rtc_wkalrm *t) { struct i2c_client *client = to_i2c_client(dev); unsigned char buf[7]; int irq_mask, err; if (client->irq <= 0) return -EINVAL; err = i2c_smbus_read_i2c_block_data(client, ABX8XX_REG_ASC, sizeof(buf), buf); if (err) return err; irq_mask = i2c_smbus_read_byte_data(client, ABX8XX_REG_IRQ); if (irq_mask < 0) return irq_mask; t->time.tm_sec = bcd2bin(buf[0] & 0x7F); t->time.tm_min = bcd2bin(buf[1] & 0x7F); t->time.tm_hour = bcd2bin(buf[2] & 0x3F); t->time.tm_mday = bcd2bin(buf[3] & 0x3F); t->time.tm_mon = bcd2bin(buf[4] & 0x1F) - 1; t->time.tm_wday = buf[5] & 0x7; t->enabled = !!(irq_mask & ABX8XX_IRQ_AIE); t->pending = (buf[6] & ABX8XX_STATUS_AF) && t->enabled; return err; } static int abx80x_set_alarm(struct device *dev, struct rtc_wkalrm *t) { struct i2c_client *client = to_i2c_client(dev); u8 alarm[6]; int err; if (client->irq <= 0) return -EINVAL; alarm[0] = 0x0; alarm[1] = bin2bcd(t->time.tm_sec); alarm[2] = bin2bcd(t->time.tm_min); alarm[3] = bin2bcd(t->time.tm_hour); alarm[4] = bin2bcd(t->time.tm_mday); alarm[5] = bin2bcd(t->time.tm_mon + 1); err = i2c_smbus_write_i2c_block_data(client, ABX8XX_REG_AHTH, sizeof(alarm), alarm); if (err < 0) { dev_err(&client->dev, "Unable to write alarm registers\n"); return -EIO; } if (t->enabled) { err = i2c_smbus_write_byte_data(client, ABX8XX_REG_IRQ, (ABX8XX_IRQ_IM_1_4 | ABX8XX_IRQ_AIE)); if (err) return err; } return 0; } static int abx80x_rtc_set_autocalibration(struct device *dev, int autocalibration) { struct i2c_client *client = to_i2c_client(dev); int retval, flags = 0; if ((autocalibration != 0) && (autocalibration != 1024) && (autocalibration != 512)) { dev_err(dev, "autocalibration value outside permitted range\n"); return -EINVAL; } flags = i2c_smbus_read_byte_data(client, ABX8XX_REG_OSC); if (flags < 0) return flags; if (autocalibration == 0) { flags &= ~(ABX8XX_OSC_ACAL_512 | ABX8XX_OSC_ACAL_1024); } else if (autocalibration == 1024) { /* 1024 autocalibration is 0x10 */ flags |= ABX8XX_OSC_ACAL_1024; flags &= ~(ABX8XX_OSC_ACAL_512); } else { /* 512 autocalibration is 0x11 */ flags |= (ABX8XX_OSC_ACAL_1024 | ABX8XX_OSC_ACAL_512); } /* Unlock write access to Oscillator Control Register */ retval = i2c_smbus_write_byte_data(client, ABX8XX_REG_CFG_KEY, ABX8XX_CFG_KEY_OSC); if (retval < 0) { dev_err(dev, "Failed to write CONFIG_KEY register\n"); return retval; } retval = i2c_smbus_write_byte_data(client, ABX8XX_REG_OSC, flags); return retval; } static int abx80x_rtc_get_autocalibration(struct device *dev) { struct i2c_client *client = to_i2c_client(dev); int flags = 0, autocalibration; flags = i2c_smbus_read_byte_data(client, ABX8XX_REG_OSC); if (flags < 0) return flags; if (flags & ABX8XX_OSC_ACAL_512) autocalibration = 512; else if (flags & ABX8XX_OSC_ACAL_1024) autocalibration = 1024; else autocalibration = 0; return autocalibration; } static ssize_t autocalibration_store(struct device *dev, struct device_attribute *attr, const char *buf, size_t count) { int retval; unsigned long autocalibration = 0; retval = kstrtoul(buf, 10, &autocalibration); if (retval < 0) { dev_err(dev, "Failed to store RTC autocalibration attribute\n"); return -EINVAL; } retval = abx80x_rtc_set_autocalibration(dev, autocalibration); return retval ? retval : count; } static ssize_t autocalibration_show(struct device *dev, struct device_attribute *attr, char *buf) { int autocalibration = 0; autocalibration = abx80x_rtc_get_autocalibration(dev); if (autocalibration < 0) { dev_err(dev, "Failed to read RTC autocalibration\n"); sprintf(buf, "0\n"); return autocalibration; } return sprintf(buf, "%d\n", autocalibration); } static DEVICE_ATTR_RW(autocalibration); static ssize_t oscillator_store(struct device *dev, struct device_attribute *attr, const char *buf, size_t count) { struct i2c_client *client = to_i2c_client(dev); int retval, flags, rc_mode = 0; if (strncmp(buf, "rc", 2) == 0) { rc_mode = 1; } else if (strncmp(buf, "xtal", 4) == 0) { rc_mode = 0; } else { dev_err(dev, "Oscillator selection value outside permitted ones\n"); return -EINVAL; } flags = i2c_smbus_read_byte_data(client, ABX8XX_REG_OSC); if (flags < 0) return flags; if (rc_mode == 0) flags &= ~(ABX8XX_OSC_OSEL); else flags |= (ABX8XX_OSC_OSEL); /* Unlock write access on Oscillator Control register */ retval = i2c_smbus_write_byte_data(client, ABX8XX_REG_CFG_KEY, ABX8XX_CFG_KEY_OSC); if (retval < 0) { dev_err(dev, "Failed to write CONFIG_KEY register\n"); return retval; } retval = i2c_smbus_write_byte_data(client, ABX8XX_REG_OSC, flags); if (retval < 0) { dev_err(dev, "Failed to write Oscillator Control register\n"); return retval; } return retval ? retval : count; } static ssize_t oscillator_show(struct device *dev, struct device_attribute *attr, char *buf) { int rc_mode = 0; struct i2c_client *client = to_i2c_client(dev); rc_mode = abx80x_is_rc_mode(client); if (rc_mode < 0) { dev_err(dev, "Failed to read RTC oscillator selection\n"); sprintf(buf, "\n"); return rc_mode; } if (rc_mode) return sprintf(buf, "rc\n"); else return sprintf(buf, "xtal\n"); } static DEVICE_ATTR_RW(oscillator); static struct attribute *rtc_calib_attrs[] = { &dev_attr_autocalibration.attr, &dev_attr_oscillator.attr, NULL, }; static const struct attribute_group rtc_calib_attr_group = { .attrs = rtc_calib_attrs, }; static int abx80x_alarm_irq_enable(struct device *dev, unsigned int enabled) { struct i2c_client *client = to_i2c_client(dev); int err; if (enabled) err = i2c_smbus_write_byte_data(client, ABX8XX_REG_IRQ, (ABX8XX_IRQ_IM_1_4 | ABX8XX_IRQ_AIE)); else err = i2c_smbus_write_byte_data(client, ABX8XX_REG_IRQ, ABX8XX_IRQ_IM_1_4); return err; } static const struct rtc_class_ops abx80x_rtc_ops = { .read_time = abx80x_rtc_read_time, .set_time = abx80x_rtc_set_time, .read_alarm = abx80x_read_alarm, .set_alarm = abx80x_set_alarm, .alarm_irq_enable = abx80x_alarm_irq_enable, }; static int abx80x_dt_trickle_cfg(struct device_node *np) { const char *diode; int trickle_cfg = 0; int i, ret; u32 tmp; ret = of_property_read_string(np, "abracon,tc-diode", &diode); if (ret) return ret; if (!strcmp(diode, "standard")) trickle_cfg |= ABX8XX_TRICKLE_STANDARD_DIODE; else if (!strcmp(diode, "schottky")) trickle_cfg |= ABX8XX_TRICKLE_SCHOTTKY_DIODE; else return -EINVAL; ret = of_property_read_u32(np, "abracon,tc-resistor", &tmp); if (ret) return ret; for (i = 0; i < sizeof(trickle_resistors); i++) if (trickle_resistors[i] == tmp) break; if (i == sizeof(trickle_resistors)) return -EINVAL; return (trickle_cfg | i); } static void rtc_calib_remove_sysfs_group(void *_dev) { struct device *dev = _dev; sysfs_remove_group(&dev->kobj, &rtc_calib_attr_group); } static int abx80x_probe(struct i2c_client *client, const struct i2c_device_id *id) { struct device_node *np = client->dev.of_node; struct rtc_device *rtc; int i, data, err, trickle_cfg = -EINVAL; char buf[7]; unsigned int part = id->driver_data; unsigned int partnumber; unsigned int majrev, minrev; unsigned int lot; unsigned int wafer; unsigned int uid; if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) return -ENODEV; err = i2c_smbus_read_i2c_block_data(client, ABX8XX_REG_ID0, sizeof(buf), buf); if (err < 0) { dev_err(&client->dev, "Unable to read partnumber\n"); return -EIO; } partnumber = (buf[0] << 8) | buf[1]; majrev = buf[2] >> 3; minrev = buf[2] & 0x7; lot = ((buf[4] & 0x80) << 2) | ((buf[6] & 0x80) << 1) | buf[3]; uid = ((buf[4] & 0x7f) << 8) | buf[5]; wafer = (buf[6] & 0x7c) >> 2; dev_info(&client->dev, "model %04x, revision %u.%u, lot %x, wafer %x, uid %x\n", partnumber, majrev, minrev, lot, wafer, uid); data = i2c_smbus_read_byte_data(client, ABX8XX_REG_CTRL1); if (data < 0) { dev_err(&client->dev, "Unable to read control register\n"); return -EIO; } err = i2c_smbus_write_byte_data(client, ABX8XX_REG_CTRL1, ((data & ~(ABX8XX_CTRL_12_24 | ABX8XX_CTRL_ARST)) | ABX8XX_CTRL_WRITE)); if (err < 0) { dev_err(&client->dev, "Unable to write control register\n"); return -EIO; } /* part autodetection */ if (part == ABX80X) { for (i = 0; abx80x_caps[i].pn; i++) if (partnumber == abx80x_caps[i].pn) break; if (abx80x_caps[i].pn == 0) { dev_err(&client->dev, "Unknown part: %04x\n", partnumber); return -EINVAL; } part = i; } if (partnumber != abx80x_caps[part].pn) { dev_err(&client->dev, "partnumber mismatch %04x != %04x\n", partnumber, abx80x_caps[part].pn); return -EINVAL; } if (np && abx80x_caps[part].has_tc) trickle_cfg = abx80x_dt_trickle_cfg(np); if (trickle_cfg > 0) { dev_info(&client->dev, "Enabling trickle charger: %02x\n", trickle_cfg); abx80x_enable_trickle_charger(client, trickle_cfg); } err = i2c_smbus_write_byte_data(client, ABX8XX_REG_CD_TIMER_CTL, BIT(2)); if (err) return err; rtc = devm_rtc_device_register(&client->dev, "abx8xx", &abx80x_rtc_ops, THIS_MODULE); if (IS_ERR(rtc)) return PTR_ERR(rtc); i2c_set_clientdata(client, rtc); if (client->irq > 0) { dev_info(&client->dev, "IRQ %d supplied\n", client->irq); err = devm_request_threaded_irq(&client->dev, client->irq, NULL, abx80x_handle_irq, IRQF_SHARED | IRQF_ONESHOT, "abx8xx", client); if (err) { dev_err(&client->dev, "unable to request IRQ, alarms disabled\n"); client->irq = 0; } } /* Export sysfs entries */ err = sysfs_create_group(&(&client->dev)->kobj, &rtc_calib_attr_group); if (err) { dev_err(&client->dev, "Failed to create sysfs group: %d\n", err); return err; } err = devm_add_action_or_reset(&client->dev, rtc_calib_remove_sysfs_group, &client->dev); if (err) dev_err(&client->dev, "Failed to add sysfs cleanup action: %d\n", err); return err; } static int abx80x_remove(struct i2c_client *client) { return 0; } static const struct i2c_device_id abx80x_id[] = { { "abx80x", ABX80X }, { "ab0801", AB0801 }, { "ab0803", AB0803 }, { "ab0804", AB0804 }, { "ab0805", AB0805 }, { "ab1801", AB1801 }, { "ab1803", AB1803 }, { "ab1804", AB1804 }, { "ab1805", AB1805 }, { "rv1805", AB1805 }, { } }; MODULE_DEVICE_TABLE(i2c, abx80x_id); static struct i2c_driver abx80x_driver = { .driver = { .name = "rtc-abx80x", }, .probe = abx80x_probe, .remove = abx80x_remove, .id_table = abx80x_id, }; module_i2c_driver(abx80x_driver); MODULE_AUTHOR("Philippe De Muyter "); MODULE_AUTHOR("Alexandre Belloni "); MODULE_DESCRIPTION("Abracon ABX80X RTC driver"); MODULE_LICENSE("GPL v2");