// SPDX-License-Identifier: GPL-2.0-only /* * Driver for Epson's RTC module RX-8025 SA/NB * * Copyright (C) 2009 Wolfgang Grandegger <wg@grandegger.com> * * Copyright (C) 2005 by Digi International Inc. * All rights reserved. * * Modified by fengjh at rising.com.cn * <lm-sensors@lm-sensors.org> * 2006.11 * * Code cleanup by Sergei Poselenov, <sposelenov@emcraft.com> * Converted to new style by Wolfgang Grandegger <wg@grandegger.com> * Alarm and periodic interrupt added by Dmitry Rakhchev <rda@emcraft.com> */ #include <linux/bcd.h> #include <linux/bitops.h> #include <linux/i2c.h> #include <linux/kernel.h> #include <linux/module.h> #include <linux/rtc.h> /* Register definitions */ #define RX8025_REG_SEC 0x00 #define RX8025_REG_MIN 0x01 #define RX8025_REG_HOUR 0x02 #define RX8025_REG_WDAY 0x03 #define RX8025_REG_MDAY 0x04 #define RX8025_REG_MONTH 0x05 #define RX8025_REG_YEAR 0x06 #define RX8025_REG_DIGOFF 0x07 #define RX8025_REG_ALWMIN 0x08 #define RX8025_REG_ALWHOUR 0x09 #define RX8025_REG_ALWWDAY 0x0a #define RX8025_REG_ALDMIN 0x0b #define RX8025_REG_ALDHOUR 0x0c /* 0x0d is reserved */ #define RX8025_REG_CTRL1 0x0e #define RX8025_REG_CTRL2 0x0f #define RX8025_BIT_CTRL1_CT (7 << 0) /* 1 Hz periodic level irq */ #define RX8025_BIT_CTRL1_CT_1HZ 4 #define RX8025_BIT_CTRL1_TEST BIT(3) #define RX8025_BIT_CTRL1_1224 BIT(5) #define RX8025_BIT_CTRL1_DALE BIT(6) #define RX8025_BIT_CTRL1_WALE BIT(7) #define RX8025_BIT_CTRL2_DAFG BIT(0) #define RX8025_BIT_CTRL2_WAFG BIT(1) #define RX8025_BIT_CTRL2_CTFG BIT(2) #define RX8025_BIT_CTRL2_PON BIT(4) #define RX8025_BIT_CTRL2_XST BIT(5) #define RX8025_BIT_CTRL2_VDET BIT(6) /* Clock precision adjustment */ #define RX8025_ADJ_RESOLUTION 3050 /* in ppb */ #define RX8025_ADJ_DATA_MAX 62 #define RX8025_ADJ_DATA_MIN -62 static const struct i2c_device_id rx8025_id[] = { { "rx8025", 0 }, { } }; MODULE_DEVICE_TABLE(i2c, rx8025_id); struct rx8025_data { struct rtc_device *rtc; u8 ctrl1; }; static s32 rx8025_read_reg(const struct i2c_client *client, u8 number) { return i2c_smbus_read_byte_data(client, number << 4); } static int rx8025_read_regs(const struct i2c_client *client, u8 number, u8 length, u8 *values) { int ret = i2c_smbus_read_i2c_block_data(client, number << 4, length, values); if (ret != length) return ret < 0 ? ret : -EIO; return 0; } static s32 rx8025_write_reg(const struct i2c_client *client, u8 number, u8 value) { return i2c_smbus_write_byte_data(client, number << 4, value); } static s32 rx8025_write_regs(const struct i2c_client *client, u8 number, u8 length, const u8 *values) { return i2c_smbus_write_i2c_block_data(client, number << 4, length, values); } static int rx8025_check_validity(struct device *dev) { struct i2c_client *client = to_i2c_client(dev); int ctrl2; ctrl2 = rx8025_read_reg(client, RX8025_REG_CTRL2); if (ctrl2 < 0) return ctrl2; if (ctrl2 & RX8025_BIT_CTRL2_VDET) dev_warn(dev, "power voltage drop detected\n"); if (ctrl2 & RX8025_BIT_CTRL2_PON) { dev_warn(dev, "power-on reset detected, date is invalid\n"); return -EINVAL; } if (!(ctrl2 & RX8025_BIT_CTRL2_XST)) { dev_warn(dev, "crystal stopped, date is invalid\n"); return -EINVAL; } return 0; } static int rx8025_reset_validity(struct i2c_client *client) { int ctrl2 = rx8025_read_reg(client, RX8025_REG_CTRL2); if (ctrl2 < 0) return ctrl2; ctrl2 &= ~(RX8025_BIT_CTRL2_PON | RX8025_BIT_CTRL2_VDET); return rx8025_write_reg(client, RX8025_REG_CTRL2, ctrl2 | RX8025_BIT_CTRL2_XST); } static irqreturn_t rx8025_handle_irq(int irq, void *dev_id) { struct i2c_client *client = dev_id; struct rx8025_data *rx8025 = i2c_get_clientdata(client); struct mutex *lock = &rx8025->rtc->ops_lock; int status; mutex_lock(lock); status = rx8025_read_reg(client, RX8025_REG_CTRL2); if (status < 0) goto out; if (!(status & RX8025_BIT_CTRL2_XST)) dev_warn(&client->dev, "Oscillation stop was detected," "you may have to readjust the clock\n"); if (status & RX8025_BIT_CTRL2_CTFG) { /* periodic */ status &= ~RX8025_BIT_CTRL2_CTFG; rtc_update_irq(rx8025->rtc, 1, RTC_PF | RTC_IRQF); } if (status & RX8025_BIT_CTRL2_DAFG) { /* alarm */ status &= RX8025_BIT_CTRL2_DAFG; if (rx8025_write_reg(client, RX8025_REG_CTRL1, rx8025->ctrl1 & ~RX8025_BIT_CTRL1_DALE)) goto out; rtc_update_irq(rx8025->rtc, 1, RTC_AF | RTC_IRQF); } out: mutex_unlock(lock); return IRQ_HANDLED; } static int rx8025_get_time(struct device *dev, struct rtc_time *dt) { struct i2c_client *client = to_i2c_client(dev); struct rx8025_data *rx8025 = dev_get_drvdata(dev); u8 date[7]; int err; err = rx8025_check_validity(dev); if (err) return err; err = rx8025_read_regs(client, RX8025_REG_SEC, 7, date); if (err) return err; dev_dbg(dev, "%s: read %7ph\n", __func__, date); dt->tm_sec = bcd2bin(date[RX8025_REG_SEC] & 0x7f); dt->tm_min = bcd2bin(date[RX8025_REG_MIN] & 0x7f); if (rx8025->ctrl1 & RX8025_BIT_CTRL1_1224) dt->tm_hour = bcd2bin(date[RX8025_REG_HOUR] & 0x3f); else dt->tm_hour = bcd2bin(date[RX8025_REG_HOUR] & 0x1f) % 12 + (date[RX8025_REG_HOUR] & 0x20 ? 12 : 0); dt->tm_mday = bcd2bin(date[RX8025_REG_MDAY] & 0x3f); dt->tm_mon = bcd2bin(date[RX8025_REG_MONTH] & 0x1f) - 1; dt->tm_year = bcd2bin(date[RX8025_REG_YEAR]) + 100; dev_dbg(dev, "%s: date %ptRr\n", __func__, dt); return 0; } static int rx8025_set_time(struct device *dev, struct rtc_time *dt) { struct i2c_client *client = to_i2c_client(dev); struct rx8025_data *rx8025 = dev_get_drvdata(dev); u8 date[7]; int ret; if ((dt->tm_year < 100) || (dt->tm_year > 199)) return -EINVAL; /* * Here the read-only bits are written as "0". I'm not sure if that * is sound. */ date[RX8025_REG_SEC] = bin2bcd(dt->tm_sec); date[RX8025_REG_MIN] = bin2bcd(dt->tm_min); if (rx8025->ctrl1 & RX8025_BIT_CTRL1_1224) date[RX8025_REG_HOUR] = bin2bcd(dt->tm_hour); else date[RX8025_REG_HOUR] = (dt->tm_hour >= 12 ? 0x20 : 0) | bin2bcd((dt->tm_hour + 11) % 12 + 1); date[RX8025_REG_WDAY] = bin2bcd(dt->tm_wday); date[RX8025_REG_MDAY] = bin2bcd(dt->tm_mday); date[RX8025_REG_MONTH] = bin2bcd(dt->tm_mon + 1); date[RX8025_REG_YEAR] = bin2bcd(dt->tm_year - 100); dev_dbg(dev, "%s: write %7ph\n", __func__, date); ret = rx8025_write_regs(client, RX8025_REG_SEC, 7, date); if (ret < 0) return ret; return rx8025_reset_validity(client); } static int rx8025_init_client(struct i2c_client *client) { struct rx8025_data *rx8025 = i2c_get_clientdata(client); u8 ctrl[2], ctrl2; int need_clear = 0; int err; err = rx8025_read_regs(client, RX8025_REG_CTRL1, 2, ctrl); if (err) goto out; /* Keep test bit zero ! */ rx8025->ctrl1 = ctrl[0] & ~RX8025_BIT_CTRL1_TEST; if (ctrl[1] & (RX8025_BIT_CTRL2_DAFG | RX8025_BIT_CTRL2_WAFG)) { dev_warn(&client->dev, "Alarm was detected\n"); need_clear = 1; } if (ctrl[1] & RX8025_BIT_CTRL2_CTFG) need_clear = 1; if (need_clear) { ctrl2 = ctrl[1]; ctrl2 &= ~(RX8025_BIT_CTRL2_CTFG | RX8025_BIT_CTRL2_WAFG | RX8025_BIT_CTRL2_DAFG); err = rx8025_write_reg(client, RX8025_REG_CTRL2, ctrl2); } out: return err; } /* Alarm support */ static int rx8025_read_alarm(struct device *dev, struct rtc_wkalrm *t) { struct i2c_client *client = to_i2c_client(dev); struct rx8025_data *rx8025 = dev_get_drvdata(dev); u8 ald[2]; int ctrl2, err; if (client->irq <= 0) return -EINVAL; err = rx8025_read_regs(client, RX8025_REG_ALDMIN, 2, ald); if (err) return err; ctrl2 = rx8025_read_reg(client, RX8025_REG_CTRL2); if (ctrl2 < 0) return ctrl2; dev_dbg(dev, "%s: read alarm 0x%02x 0x%02x ctrl2 %02x\n", __func__, ald[0], ald[1], ctrl2); /* Hardware alarms precision is 1 minute! */ t->time.tm_sec = 0; t->time.tm_min = bcd2bin(ald[0] & 0x7f); if (rx8025->ctrl1 & RX8025_BIT_CTRL1_1224) t->time.tm_hour = bcd2bin(ald[1] & 0x3f); else t->time.tm_hour = bcd2bin(ald[1] & 0x1f) % 12 + (ald[1] & 0x20 ? 12 : 0); dev_dbg(dev, "%s: date: %ptRr\n", __func__, &t->time); t->enabled = !!(rx8025->ctrl1 & RX8025_BIT_CTRL1_DALE); t->pending = (ctrl2 & RX8025_BIT_CTRL2_DAFG) && t->enabled; return err; } static int rx8025_set_alarm(struct device *dev, struct rtc_wkalrm *t) { struct i2c_client *client = to_i2c_client(dev); struct rx8025_data *rx8025 = dev_get_drvdata(dev); u8 ald[2]; int err; if (client->irq <= 0) return -EINVAL; /* * Hardware alarm precision is 1 minute! * round up to nearest minute */ if (t->time.tm_sec) { time64_t alarm_time = rtc_tm_to_time64(&t->time); alarm_time += 60 - t->time.tm_sec; rtc_time64_to_tm(alarm_time, &t->time); } ald[0] = bin2bcd(t->time.tm_min); if (rx8025->ctrl1 & RX8025_BIT_CTRL1_1224) ald[1] = bin2bcd(t->time.tm_hour); else ald[1] = (t->time.tm_hour >= 12 ? 0x20 : 0) | bin2bcd((t->time.tm_hour + 11) % 12 + 1); dev_dbg(dev, "%s: write 0x%02x 0x%02x\n", __func__, ald[0], ald[1]); if (rx8025->ctrl1 & RX8025_BIT_CTRL1_DALE) { rx8025->ctrl1 &= ~RX8025_BIT_CTRL1_DALE; err = rx8025_write_reg(client, RX8025_REG_CTRL1, rx8025->ctrl1); if (err) return err; } err = rx8025_write_regs(client, RX8025_REG_ALDMIN, 2, ald); if (err) return err; if (t->enabled) { rx8025->ctrl1 |= RX8025_BIT_CTRL1_DALE; err = rx8025_write_reg(client, RX8025_REG_CTRL1, rx8025->ctrl1); if (err) return err; } return 0; } static int rx8025_alarm_irq_enable(struct device *dev, unsigned int enabled) { struct i2c_client *client = to_i2c_client(dev); struct rx8025_data *rx8025 = dev_get_drvdata(dev); u8 ctrl1; int err; ctrl1 = rx8025->ctrl1; if (enabled) ctrl1 |= RX8025_BIT_CTRL1_DALE; else ctrl1 &= ~RX8025_BIT_CTRL1_DALE; if (ctrl1 != rx8025->ctrl1) { rx8025->ctrl1 = ctrl1; err = rx8025_write_reg(client, RX8025_REG_CTRL1, rx8025->ctrl1); if (err) return err; } return 0; } static const struct rtc_class_ops rx8025_rtc_ops = { .read_time = rx8025_get_time, .set_time = rx8025_set_time, .read_alarm = rx8025_read_alarm, .set_alarm = rx8025_set_alarm, .alarm_irq_enable = rx8025_alarm_irq_enable, }; /* * Clock precision adjustment support * * According to the RX8025 SA/NB application manual the frequency and * temperature characteristics can be approximated using the following * equation: * * df = a * (ut - t)**2 * * df: Frequency deviation in any temperature * a : Coefficient = (-35 +-5) * 10**-9 * ut: Ultimate temperature in degree = +25 +-5 degree * t : Any temperature in degree * * Note that the clock adjustment in ppb must be entered (which is * the negative value of the deviation). */ static int rx8025_get_clock_adjust(struct device *dev, int *adj) { struct i2c_client *client = to_i2c_client(dev); int digoff; digoff = rx8025_read_reg(client, RX8025_REG_DIGOFF); if (digoff < 0) return digoff; *adj = digoff >= 64 ? digoff - 128 : digoff; if (*adj > 0) (*adj)--; *adj *= -RX8025_ADJ_RESOLUTION; return 0; } static int rx8025_set_clock_adjust(struct device *dev, int adj) { struct i2c_client *client = to_i2c_client(dev); u8 digoff; int err; adj /= -RX8025_ADJ_RESOLUTION; if (adj > RX8025_ADJ_DATA_MAX) adj = RX8025_ADJ_DATA_MAX; else if (adj < RX8025_ADJ_DATA_MIN) adj = RX8025_ADJ_DATA_MIN; else if (adj > 0) adj++; else if (adj < 0) adj += 128; digoff = adj; err = rx8025_write_reg(client, RX8025_REG_DIGOFF, digoff); if (err) return err; dev_dbg(dev, "%s: write 0x%02x\n", __func__, digoff); return 0; } static ssize_t rx8025_sysfs_show_clock_adjust(struct device *dev, struct device_attribute *attr, char *buf) { int err, adj; err = rx8025_get_clock_adjust(dev, &adj); if (err) return err; return sprintf(buf, "%d\n", adj); } static ssize_t rx8025_sysfs_store_clock_adjust(struct device *dev, struct device_attribute *attr, const char *buf, size_t count) { int adj, err; if (sscanf(buf, "%i", &adj) != 1) return -EINVAL; err = rx8025_set_clock_adjust(dev, adj); return err ? err : count; } static DEVICE_ATTR(clock_adjust_ppb, S_IRUGO | S_IWUSR, rx8025_sysfs_show_clock_adjust, rx8025_sysfs_store_clock_adjust); static int rx8025_sysfs_register(struct device *dev) { return device_create_file(dev, &dev_attr_clock_adjust_ppb); } static void rx8025_sysfs_unregister(struct device *dev) { device_remove_file(dev, &dev_attr_clock_adjust_ppb); } static int rx8025_probe(struct i2c_client *client, const struct i2c_device_id *id) { struct i2c_adapter *adapter = client->adapter; struct rx8025_data *rx8025; int err = 0; if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA | I2C_FUNC_SMBUS_I2C_BLOCK)) { dev_err(&adapter->dev, "doesn't support required functionality\n"); return -EIO; } rx8025 = devm_kzalloc(&client->dev, sizeof(*rx8025), GFP_KERNEL); if (!rx8025) return -ENOMEM; i2c_set_clientdata(client, rx8025); err = rx8025_init_client(client); if (err) return err; rx8025->rtc = devm_rtc_device_register(&client->dev, client->name, &rx8025_rtc_ops, THIS_MODULE); if (IS_ERR(rx8025->rtc)) { dev_err(&client->dev, "unable to register the class device\n"); return PTR_ERR(rx8025->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, rx8025_handle_irq, IRQF_ONESHOT, "rx8025", client); if (err) { dev_err(&client->dev, "unable to request IRQ, alarms disabled\n"); client->irq = 0; } } rx8025->rtc->max_user_freq = 1; /* the rx8025 alarm only supports a minute accuracy */ rx8025->rtc->uie_unsupported = 1; err = rx8025_sysfs_register(&client->dev); return err; } static int rx8025_remove(struct i2c_client *client) { rx8025_sysfs_unregister(&client->dev); return 0; } static struct i2c_driver rx8025_driver = { .driver = { .name = "rtc-rx8025", }, .probe = rx8025_probe, .remove = rx8025_remove, .id_table = rx8025_id, }; module_i2c_driver(rx8025_driver); MODULE_AUTHOR("Wolfgang Grandegger <wg@grandegger.com>"); MODULE_DESCRIPTION("RX-8025 SA/NB RTC driver"); MODULE_LICENSE("GPL");