/* * An I2C and SPI driver for the NXP PCF2127/29 RTC * Copyright 2013 Til-Technologies * * Author: Renaud Cerrato <r.cerrato@til-technologies.fr> * * based on the other drivers in this same directory. * * Datasheet: http://cache.nxp.com/documents/data_sheet/PCF2127.pdf * * 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 <linux/i2c.h> #include <linux/spi/spi.h> #include <linux/bcd.h> #include <linux/rtc.h> #include <linux/slab.h> #include <linux/module.h> #include <linux/of.h> #include <linux/regmap.h> #define PCF2127_REG_CTRL1 (0x00) /* Control Register 1 */ #define PCF2127_REG_CTRL2 (0x01) /* Control Register 2 */ #define PCF2127_REG_CTRL3 (0x02) /* Control Register 3 */ #define PCF2127_REG_CTRL3_BLF BIT(2) #define PCF2127_REG_SC (0x03) /* datetime */ #define PCF2127_REG_MN (0x04) #define PCF2127_REG_HR (0x05) #define PCF2127_REG_DM (0x06) #define PCF2127_REG_DW (0x07) #define PCF2127_REG_MO (0x08) #define PCF2127_REG_YR (0x09) /* the pcf2127 has 512 bytes nvmem, pcf2129 doesn't */ #define PCF2127_REG_RAM_addr_MSB 0x1a #define PCF2127_REG_RAM_wrt_cmd 0x1c #define PCF2127_REG_RAM_rd_cmd 0x1d #define PCF2127_OSF BIT(7) /* Oscillator Fail flag */ struct pcf2127 { struct rtc_device *rtc; struct regmap *regmap; }; /* * In the routines that deal directly with the pcf2127 hardware, we use * rtc_time -- month 0-11, hour 0-23, yr = calendar year-epoch. */ static int pcf2127_rtc_read_time(struct device *dev, struct rtc_time *tm) { struct pcf2127 *pcf2127 = dev_get_drvdata(dev); unsigned char buf[10]; int ret; int i; for (i = 0; i <= PCF2127_REG_CTRL3; i++) { ret = regmap_read(pcf2127->regmap, PCF2127_REG_CTRL1 + i, (unsigned int *)(buf + i)); if (ret) { dev_err(dev, "%s: read error\n", __func__); return ret; } } ret = regmap_bulk_read(pcf2127->regmap, PCF2127_REG_SC, (buf + PCF2127_REG_SC), ARRAY_SIZE(buf) - PCF2127_REG_SC); if (ret) { dev_err(dev, "%s: read error\n", __func__); return ret; } if (buf[PCF2127_REG_CTRL3] & PCF2127_REG_CTRL3_BLF) dev_info(dev, "low voltage detected, check/replace RTC battery.\n"); if (buf[PCF2127_REG_SC] & PCF2127_OSF) { /* * no need clear the flag here, * it will be cleared once the new date is saved */ dev_warn(dev, "oscillator stop detected, date/time is not reliable\n"); return -EINVAL; } dev_dbg(dev, "%s: raw data is cr1=%02x, cr2=%02x, cr3=%02x, " "sec=%02x, min=%02x, hr=%02x, " "mday=%02x, wday=%02x, mon=%02x, year=%02x\n", __func__, buf[0], buf[1], buf[2], buf[3], buf[4], buf[5], buf[6], buf[7], buf[8], buf[9]); tm->tm_sec = bcd2bin(buf[PCF2127_REG_SC] & 0x7F); tm->tm_min = bcd2bin(buf[PCF2127_REG_MN] & 0x7F); tm->tm_hour = bcd2bin(buf[PCF2127_REG_HR] & 0x3F); /* rtc hr 0-23 */ tm->tm_mday = bcd2bin(buf[PCF2127_REG_DM] & 0x3F); tm->tm_wday = buf[PCF2127_REG_DW] & 0x07; tm->tm_mon = bcd2bin(buf[PCF2127_REG_MO] & 0x1F) - 1; /* rtc mn 1-12 */ tm->tm_year = bcd2bin(buf[PCF2127_REG_YR]); if (tm->tm_year < 70) tm->tm_year += 100; /* assume we are in 1970...2069 */ 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 pcf2127_rtc_set_time(struct device *dev, struct rtc_time *tm) { struct pcf2127 *pcf2127 = dev_get_drvdata(dev); unsigned char buf[7]; int i = 0, err; 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[i++] = bin2bcd(tm->tm_sec); /* this will also clear OSF flag */ buf[i++] = bin2bcd(tm->tm_min); buf[i++] = bin2bcd(tm->tm_hour); buf[i++] = bin2bcd(tm->tm_mday); buf[i++] = tm->tm_wday & 0x07; /* month, 1 - 12 */ buf[i++] = bin2bcd(tm->tm_mon + 1); /* year */ buf[i++] = bin2bcd(tm->tm_year % 100); /* write register's data */ err = regmap_bulk_write(pcf2127->regmap, PCF2127_REG_SC, buf, i); if (err) { dev_err(dev, "%s: err=%d", __func__, err); return err; } return 0; } #ifdef CONFIG_RTC_INTF_DEV static int pcf2127_rtc_ioctl(struct device *dev, unsigned int cmd, unsigned long arg) { struct pcf2127 *pcf2127 = dev_get_drvdata(dev); int touser; int ret; switch (cmd) { case RTC_VL_READ: ret = regmap_read(pcf2127->regmap, PCF2127_REG_CTRL3, &touser); if (ret) return ret; touser = touser & PCF2127_REG_CTRL3_BLF ? 1 : 0; if (copy_to_user((void __user *)arg, &touser, sizeof(int))) return -EFAULT; return 0; default: return -ENOIOCTLCMD; } } #else #define pcf2127_rtc_ioctl NULL #endif static const struct rtc_class_ops pcf2127_rtc_ops = { .ioctl = pcf2127_rtc_ioctl, .read_time = pcf2127_rtc_read_time, .set_time = pcf2127_rtc_set_time, }; static int pcf2127_nvmem_read(void *priv, unsigned int offset, void *val, size_t bytes) { struct pcf2127 *pcf2127 = priv; int ret; unsigned char offsetbuf[] = { offset >> 8, offset }; ret = regmap_bulk_write(pcf2127->regmap, PCF2127_REG_RAM_addr_MSB, offsetbuf, 2); if (ret) return ret; ret = regmap_bulk_read(pcf2127->regmap, PCF2127_REG_RAM_rd_cmd, val, bytes); return ret ?: bytes; } static int pcf2127_nvmem_write(void *priv, unsigned int offset, void *val, size_t bytes) { struct pcf2127 *pcf2127 = priv; int ret; unsigned char offsetbuf[] = { offset >> 8, offset }; ret = regmap_bulk_write(pcf2127->regmap, PCF2127_REG_RAM_addr_MSB, offsetbuf, 2); if (ret) return ret; ret = regmap_bulk_write(pcf2127->regmap, PCF2127_REG_RAM_wrt_cmd, val, bytes); return ret ?: bytes; } static int pcf2127_probe(struct device *dev, struct regmap *regmap, const char *name, bool has_nvmem) { struct pcf2127 *pcf2127; int ret = 0; dev_dbg(dev, "%s\n", __func__); pcf2127 = devm_kzalloc(dev, sizeof(*pcf2127), GFP_KERNEL); if (!pcf2127) return -ENOMEM; pcf2127->regmap = regmap; dev_set_drvdata(dev, pcf2127); pcf2127->rtc = devm_rtc_device_register(dev, name, &pcf2127_rtc_ops, THIS_MODULE); if (IS_ERR(pcf2127->rtc)) return PTR_ERR(pcf2127->rtc); if (has_nvmem) { struct nvmem_config nvmem_cfg = { .priv = pcf2127, .reg_read = pcf2127_nvmem_read, .reg_write = pcf2127_nvmem_write, .size = 512, }; ret = rtc_nvmem_register(pcf2127->rtc, &nvmem_cfg); } return ret; } #ifdef CONFIG_OF static const struct of_device_id pcf2127_of_match[] = { { .compatible = "nxp,pcf2127" }, { .compatible = "nxp,pcf2129" }, {} }; MODULE_DEVICE_TABLE(of, pcf2127_of_match); #endif #if IS_ENABLED(CONFIG_I2C) static int pcf2127_i2c_write(void *context, const void *data, size_t count) { struct device *dev = context; struct i2c_client *client = to_i2c_client(dev); int ret; ret = i2c_master_send(client, data, count); if (ret != count) return ret < 0 ? ret : -EIO; return 0; } static int pcf2127_i2c_gather_write(void *context, const void *reg, size_t reg_size, const void *val, size_t val_size) { struct device *dev = context; struct i2c_client *client = to_i2c_client(dev); int ret; void *buf; if (WARN_ON(reg_size != 1)) return -EINVAL; buf = kmalloc(val_size + 1, GFP_KERNEL); if (!buf) return -ENOMEM; memcpy(buf, reg, 1); memcpy(buf + 1, val, val_size); ret = i2c_master_send(client, buf, val_size + 1); kfree(buf); if (ret != val_size + 1) return ret < 0 ? ret : -EIO; return 0; } static int pcf2127_i2c_read(void *context, const void *reg, size_t reg_size, void *val, size_t val_size) { struct device *dev = context; struct i2c_client *client = to_i2c_client(dev); int ret; if (WARN_ON(reg_size != 1)) return -EINVAL; ret = i2c_master_send(client, reg, 1); if (ret != 1) return ret < 0 ? ret : -EIO; ret = i2c_master_recv(client, val, val_size); if (ret != val_size) return ret < 0 ? ret : -EIO; return 0; } /* * The reason we need this custom regmap_bus instead of using regmap_init_i2c() * is that the STOP condition is required between set register address and * read register data when reading from registers. */ static const struct regmap_bus pcf2127_i2c_regmap = { .write = pcf2127_i2c_write, .gather_write = pcf2127_i2c_gather_write, .read = pcf2127_i2c_read, }; static struct i2c_driver pcf2127_i2c_driver; static int pcf2127_i2c_probe(struct i2c_client *client, const struct i2c_device_id *id) { struct regmap *regmap; static const struct regmap_config config = { .reg_bits = 8, .val_bits = 8, }; if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) return -ENODEV; regmap = devm_regmap_init(&client->dev, &pcf2127_i2c_regmap, &client->dev, &config); if (IS_ERR(regmap)) { dev_err(&client->dev, "%s: regmap allocation failed: %ld\n", __func__, PTR_ERR(regmap)); return PTR_ERR(regmap); } return pcf2127_probe(&client->dev, regmap, pcf2127_i2c_driver.driver.name, id->driver_data); } static const struct i2c_device_id pcf2127_i2c_id[] = { { "pcf2127", 1 }, { "pcf2129", 0 }, { } }; MODULE_DEVICE_TABLE(i2c, pcf2127_i2c_id); static struct i2c_driver pcf2127_i2c_driver = { .driver = { .name = "rtc-pcf2127-i2c", .of_match_table = of_match_ptr(pcf2127_of_match), }, .probe = pcf2127_i2c_probe, .id_table = pcf2127_i2c_id, }; static int pcf2127_i2c_register_driver(void) { return i2c_add_driver(&pcf2127_i2c_driver); } static void pcf2127_i2c_unregister_driver(void) { i2c_del_driver(&pcf2127_i2c_driver); } #else static int pcf2127_i2c_register_driver(void) { return 0; } static void pcf2127_i2c_unregister_driver(void) { } #endif #if IS_ENABLED(CONFIG_SPI_MASTER) static struct spi_driver pcf2127_spi_driver; static int pcf2127_spi_probe(struct spi_device *spi) { static const struct regmap_config config = { .reg_bits = 8, .val_bits = 8, .read_flag_mask = 0xa0, .write_flag_mask = 0x20, }; struct regmap *regmap; regmap = devm_regmap_init_spi(spi, &config); if (IS_ERR(regmap)) { dev_err(&spi->dev, "%s: regmap allocation failed: %ld\n", __func__, PTR_ERR(regmap)); return PTR_ERR(regmap); } return pcf2127_probe(&spi->dev, regmap, pcf2127_spi_driver.driver.name, spi_get_device_id(spi)->driver_data); } static const struct spi_device_id pcf2127_spi_id[] = { { "pcf2127", 1 }, { "pcf2129", 0 }, { } }; MODULE_DEVICE_TABLE(spi, pcf2127_spi_id); static struct spi_driver pcf2127_spi_driver = { .driver = { .name = "rtc-pcf2127-spi", .of_match_table = of_match_ptr(pcf2127_of_match), }, .probe = pcf2127_spi_probe, .id_table = pcf2127_spi_id, }; static int pcf2127_spi_register_driver(void) { return spi_register_driver(&pcf2127_spi_driver); } static void pcf2127_spi_unregister_driver(void) { spi_unregister_driver(&pcf2127_spi_driver); } #else static int pcf2127_spi_register_driver(void) { return 0; } static void pcf2127_spi_unregister_driver(void) { } #endif static int __init pcf2127_init(void) { int ret; ret = pcf2127_i2c_register_driver(); if (ret) { pr_err("Failed to register pcf2127 i2c driver: %d\n", ret); return ret; } ret = pcf2127_spi_register_driver(); if (ret) { pr_err("Failed to register pcf2127 spi driver: %d\n", ret); pcf2127_i2c_unregister_driver(); } return ret; } module_init(pcf2127_init) static void __exit pcf2127_exit(void) { pcf2127_spi_unregister_driver(); pcf2127_i2c_unregister_driver(); } module_exit(pcf2127_exit) MODULE_AUTHOR("Renaud Cerrato <r.cerrato@til-technologies.fr>"); MODULE_DESCRIPTION("NXP PCF2127/29 RTC driver"); MODULE_LICENSE("GPL v2");