// SPDX-License-Identifier: GPL-2.0-only /* * An I2C driver for the Epson RX8581 RTC * * Author: Martyn Welch * Copyright 2008 GE Intelligent Platforms Embedded Systems, Inc. * * Based on: rtc-pcf8563.c (An I2C driver for the Philips PCF8563 RTC) * Copyright 2005-06 Tower Technologies */ #include #include #include #include #include #include #include #include #define RX8581_REG_SC 0x00 /* Second in BCD */ #define RX8581_REG_MN 0x01 /* Minute in BCD */ #define RX8581_REG_HR 0x02 /* Hour in BCD */ #define RX8581_REG_DW 0x03 /* Day of Week */ #define RX8581_REG_DM 0x04 /* Day of Month in BCD */ #define RX8581_REG_MO 0x05 /* Month in BCD */ #define RX8581_REG_YR 0x06 /* Year in BCD */ #define RX8581_REG_RAM 0x07 /* RAM */ #define RX8581_REG_AMN 0x08 /* Alarm Min in BCD*/ #define RX8581_REG_AHR 0x09 /* Alarm Hour in BCD */ #define RX8581_REG_ADM 0x0A #define RX8581_REG_ADW 0x0A #define RX8581_REG_TMR0 0x0B #define RX8581_REG_TMR1 0x0C #define RX8581_REG_EXT 0x0D /* Extension Register */ #define RX8581_REG_FLAG 0x0E /* Flag Register */ #define RX8581_REG_CTRL 0x0F /* Control Register */ /* Flag Register bit definitions */ #define RX8581_FLAG_UF 0x20 /* Update */ #define RX8581_FLAG_TF 0x10 /* Timer */ #define RX8581_FLAG_AF 0x08 /* Alarm */ #define RX8581_FLAG_VLF 0x02 /* Voltage Low */ /* Control Register bit definitions */ #define RX8581_CTRL_UIE 0x20 /* Update Interrupt Enable */ #define RX8581_CTRL_TIE 0x10 /* Timer Interrupt Enable */ #define RX8581_CTRL_AIE 0x08 /* Alarm Interrupt Enable */ #define RX8581_CTRL_STOP 0x02 /* STOP bit */ #define RX8581_CTRL_RESET 0x01 /* RESET bit */ #define RX8571_USER_RAM 0x10 #define RX8571_NVRAM_SIZE 0x10 struct rx8581 { struct regmap *regmap; struct rtc_device *rtc; }; struct rx85x1_config { struct regmap_config regmap; unsigned int num_nvram; }; /* * In the routines that deal directly with the rx8581 hardware, we use * rtc_time -- month 0-11, hour 0-23, yr = calendar year-epoch. */ static int rx8581_rtc_read_time(struct device *dev, struct rtc_time *tm) { struct i2c_client *client = to_i2c_client(dev); unsigned char date[7]; unsigned int data; int err; struct rx8581 *rx8581 = i2c_get_clientdata(client); /* First we ensure that the "update flag" is not set, we read the * time and date then re-read the "update flag". If the update flag * has been set, we know that the time has changed during the read so * we repeat the whole process again. */ err = regmap_read(rx8581->regmap, RX8581_REG_FLAG, &data); if (err < 0) return err; if (data & RX8581_FLAG_VLF) { dev_warn(dev, "low voltage detected, date/time is not reliable.\n"); return -EINVAL; } do { /* If update flag set, clear it */ if (data & RX8581_FLAG_UF) { err = regmap_write(rx8581->regmap, RX8581_REG_FLAG, data & ~RX8581_FLAG_UF); if (err < 0) return err; } /* Now read time and date */ err = regmap_bulk_read(rx8581->regmap, RX8581_REG_SC, date, sizeof(date)); if (err < 0) return err; /* Check flag register */ err = regmap_read(rx8581->regmap, RX8581_REG_FLAG, &data); if (err < 0) return err; } while (data & RX8581_FLAG_UF); dev_dbg(dev, "%s: raw data is sec=%02x, min=%02x, hr=%02x, " "wday=%02x, mday=%02x, mon=%02x, year=%02x\n", __func__, date[0], date[1], date[2], date[3], date[4], date[5], date[6]); tm->tm_sec = bcd2bin(date[RX8581_REG_SC] & 0x7F); tm->tm_min = bcd2bin(date[RX8581_REG_MN] & 0x7F); tm->tm_hour = bcd2bin(date[RX8581_REG_HR] & 0x3F); /* rtc hr 0-23 */ tm->tm_wday = ilog2(date[RX8581_REG_DW] & 0x7F); tm->tm_mday = bcd2bin(date[RX8581_REG_DM] & 0x3F); tm->tm_mon = bcd2bin(date[RX8581_REG_MO] & 0x1F) - 1; /* rtc mn 1-12 */ tm->tm_year = bcd2bin(date[RX8581_REG_YR]) + 100; dev_dbg(dev, "%s: tm is secs=%d, mins=%d, hours=%d, " "mday=%d, mon=%d, year=%d, wday=%d\n", __func__, tm->tm_sec, tm->tm_min, tm->tm_hour, tm->tm_mday, tm->tm_mon, tm->tm_year, tm->tm_wday); return 0; } static int rx8581_rtc_set_time(struct device *dev, struct rtc_time *tm) { struct i2c_client *client = to_i2c_client(dev); int err; unsigned char buf[7]; struct rx8581 *rx8581 = i2c_get_clientdata(client); dev_dbg(dev, "%s: secs=%d, mins=%d, hours=%d, " "mday=%d, mon=%d, year=%d, wday=%d\n", __func__, tm->tm_sec, tm->tm_min, tm->tm_hour, tm->tm_mday, tm->tm_mon, tm->tm_year, tm->tm_wday); /* hours, minutes and seconds */ buf[RX8581_REG_SC] = bin2bcd(tm->tm_sec); buf[RX8581_REG_MN] = bin2bcd(tm->tm_min); buf[RX8581_REG_HR] = bin2bcd(tm->tm_hour); buf[RX8581_REG_DM] = bin2bcd(tm->tm_mday); /* month, 1 - 12 */ buf[RX8581_REG_MO] = bin2bcd(tm->tm_mon + 1); /* year and century */ buf[RX8581_REG_YR] = bin2bcd(tm->tm_year - 100); buf[RX8581_REG_DW] = (0x1 << tm->tm_wday); /* Stop the clock */ err = regmap_update_bits(rx8581->regmap, RX8581_REG_CTRL, RX8581_CTRL_STOP, RX8581_CTRL_STOP); if (err < 0) return err; /* write register's data */ err = regmap_bulk_write(rx8581->regmap, RX8581_REG_SC, buf, sizeof(buf)); if (err < 0) return err; /* get VLF and clear it */ err = regmap_update_bits(rx8581->regmap, RX8581_REG_FLAG, RX8581_FLAG_VLF, 0); if (err < 0) return err; /* Restart the clock */ return regmap_update_bits(rx8581->regmap, RX8581_REG_CTRL, RX8581_CTRL_STOP, 0); } static const struct rtc_class_ops rx8581_rtc_ops = { .read_time = rx8581_rtc_read_time, .set_time = rx8581_rtc_set_time, }; static int rx8571_nvram_read(void *priv, unsigned int offset, void *val, size_t bytes) { struct rx8581 *rx8581 = priv; return regmap_bulk_read(rx8581->regmap, RX8571_USER_RAM + offset, val, bytes); } static int rx8571_nvram_write(void *priv, unsigned int offset, void *val, size_t bytes) { struct rx8581 *rx8581 = priv; return regmap_bulk_write(rx8581->regmap, RX8571_USER_RAM + offset, val, bytes); } static int rx85x1_nvram_read(void *priv, unsigned int offset, void *val, size_t bytes) { struct rx8581 *rx8581 = priv; unsigned int tmp_val; int ret; ret = regmap_read(rx8581->regmap, RX8581_REG_RAM, &tmp_val); (*(unsigned char *)val) = (unsigned char) tmp_val; return ret; } static int rx85x1_nvram_write(void *priv, unsigned int offset, void *val, size_t bytes) { struct rx8581 *rx8581 = priv; unsigned char tmp_val; tmp_val = *((unsigned char *)val); return regmap_write(rx8581->regmap, RX8581_REG_RAM, (unsigned int)tmp_val); } static const struct rx85x1_config rx8581_config = { .regmap = { .reg_bits = 8, .val_bits = 8, .max_register = 0xf, }, .num_nvram = 1 }; static const struct rx85x1_config rx8571_config = { .regmap = { .reg_bits = 8, .val_bits = 8, .max_register = 0x1f, }, .num_nvram = 2 }; static int rx8581_probe(struct i2c_client *client, const struct i2c_device_id *id) { struct rx8581 *rx8581; const struct rx85x1_config *config = &rx8581_config; const void *data = of_device_get_match_data(&client->dev); static struct nvmem_config nvmem_cfg[] = { { .name = "rx85x1-", .word_size = 1, .stride = 1, .size = 1, .reg_read = rx85x1_nvram_read, .reg_write = rx85x1_nvram_write, }, { .name = "rx8571-", .word_size = 1, .stride = 1, .size = RX8571_NVRAM_SIZE, .reg_read = rx8571_nvram_read, .reg_write = rx8571_nvram_write, }, }; int ret, i; dev_dbg(&client->dev, "%s\n", __func__); if (data) config = data; rx8581 = devm_kzalloc(&client->dev, sizeof(struct rx8581), GFP_KERNEL); if (!rx8581) return -ENOMEM; i2c_set_clientdata(client, rx8581); rx8581->regmap = devm_regmap_init_i2c(client, &config->regmap); if (IS_ERR(rx8581->regmap)) return PTR_ERR(rx8581->regmap); rx8581->rtc = devm_rtc_allocate_device(&client->dev); if (IS_ERR(rx8581->rtc)) return PTR_ERR(rx8581->rtc); rx8581->rtc->ops = &rx8581_rtc_ops; rx8581->rtc->range_min = RTC_TIMESTAMP_BEGIN_2000; rx8581->rtc->range_max = RTC_TIMESTAMP_END_2099; rx8581->rtc->start_secs = 0; rx8581->rtc->set_start_time = true; ret = rtc_register_device(rx8581->rtc); for (i = 0; i < config->num_nvram; i++) { nvmem_cfg[i].priv = rx8581; rtc_nvmem_register(rx8581->rtc, &nvmem_cfg[i]); } return ret; } static const struct i2c_device_id rx8581_id[] = { { "rx8581", 0 }, { } }; MODULE_DEVICE_TABLE(i2c, rx8581_id); static const struct of_device_id rx8581_of_match[] = { { .compatible = "epson,rx8571", .data = &rx8571_config }, { .compatible = "epson,rx8581", .data = &rx8581_config }, { /* sentinel */ } }; MODULE_DEVICE_TABLE(of, rx8581_of_match); static struct i2c_driver rx8581_driver = { .driver = { .name = "rtc-rx8581", .of_match_table = of_match_ptr(rx8581_of_match), }, .probe = rx8581_probe, .id_table = rx8581_id, }; module_i2c_driver(rx8581_driver); MODULE_AUTHOR("Martyn Welch "); MODULE_DESCRIPTION("Epson RX-8571/RX-8581 RTC driver"); MODULE_LICENSE("GPL");