118cb6368SRenaud Cerrato /* 218cb6368SRenaud Cerrato * An I2C driver for the NXP PCF2127 RTC 318cb6368SRenaud Cerrato * Copyright 2013 Til-Technologies 418cb6368SRenaud Cerrato * 518cb6368SRenaud Cerrato * Author: Renaud Cerrato <r.cerrato@til-technologies.fr> 618cb6368SRenaud Cerrato * 718cb6368SRenaud Cerrato * based on the other drivers in this same directory. 818cb6368SRenaud Cerrato * 918cb6368SRenaud Cerrato * http://www.nxp.com/documents/data_sheet/PCF2127AT.pdf 1018cb6368SRenaud Cerrato * 1118cb6368SRenaud Cerrato * This program is free software; you can redistribute it and/or modify 1218cb6368SRenaud Cerrato * it under the terms of the GNU General Public License version 2 as 1318cb6368SRenaud Cerrato * published by the Free Software Foundation. 1418cb6368SRenaud Cerrato */ 1518cb6368SRenaud Cerrato 1618cb6368SRenaud Cerrato #include <linux/i2c.h> 1718cb6368SRenaud Cerrato #include <linux/bcd.h> 1818cb6368SRenaud Cerrato #include <linux/rtc.h> 1918cb6368SRenaud Cerrato #include <linux/slab.h> 2018cb6368SRenaud Cerrato #include <linux/module.h> 2118cb6368SRenaud Cerrato #include <linux/of.h> 2218cb6368SRenaud Cerrato 2318cb6368SRenaud Cerrato #define DRV_VERSION "0.0.1" 2418cb6368SRenaud Cerrato 2518cb6368SRenaud Cerrato #define PCF2127_REG_CTRL1 (0x00) /* Control Register 1 */ 2618cb6368SRenaud Cerrato #define PCF2127_REG_CTRL2 (0x01) /* Control Register 2 */ 2718cb6368SRenaud Cerrato #define PCF2127_REG_CTRL3 (0x02) /* Control Register 3 */ 2818cb6368SRenaud Cerrato #define PCF2127_REG_SC (0x03) /* datetime */ 2918cb6368SRenaud Cerrato #define PCF2127_REG_MN (0x04) 3018cb6368SRenaud Cerrato #define PCF2127_REG_HR (0x05) 3118cb6368SRenaud Cerrato #define PCF2127_REG_DM (0x06) 3218cb6368SRenaud Cerrato #define PCF2127_REG_DW (0x07) 3318cb6368SRenaud Cerrato #define PCF2127_REG_MO (0x08) 3418cb6368SRenaud Cerrato #define PCF2127_REG_YR (0x09) 3518cb6368SRenaud Cerrato 3618cb6368SRenaud Cerrato static struct i2c_driver pcf2127_driver; 3718cb6368SRenaud Cerrato 3818cb6368SRenaud Cerrato struct pcf2127 { 3918cb6368SRenaud Cerrato struct rtc_device *rtc; 4018cb6368SRenaud Cerrato int voltage_low; /* indicates if a low_voltage was detected */ 4118cb6368SRenaud Cerrato }; 4218cb6368SRenaud Cerrato 4318cb6368SRenaud Cerrato /* 4418cb6368SRenaud Cerrato * In the routines that deal directly with the pcf2127 hardware, we use 4518cb6368SRenaud Cerrato * rtc_time -- month 0-11, hour 0-23, yr = calendar year-epoch. 4618cb6368SRenaud Cerrato */ 4718cb6368SRenaud Cerrato static int pcf2127_get_datetime(struct i2c_client *client, struct rtc_time *tm) 4818cb6368SRenaud Cerrato { 4918cb6368SRenaud Cerrato struct pcf2127 *pcf2127 = i2c_get_clientdata(client); 5018cb6368SRenaud Cerrato unsigned char buf[10] = { PCF2127_REG_CTRL1 }; 5118cb6368SRenaud Cerrato 5218cb6368SRenaud Cerrato /* read registers */ 5318cb6368SRenaud Cerrato if (i2c_master_send(client, buf, 1) != 1 || 5418cb6368SRenaud Cerrato i2c_master_recv(client, buf, sizeof(buf)) != sizeof(buf)) { 5518cb6368SRenaud Cerrato dev_err(&client->dev, "%s: read error\n", __func__); 5618cb6368SRenaud Cerrato return -EIO; 5718cb6368SRenaud Cerrato } 5818cb6368SRenaud Cerrato 5918cb6368SRenaud Cerrato if (buf[PCF2127_REG_CTRL3] & 0x04) { 6018cb6368SRenaud Cerrato pcf2127->voltage_low = 1; 6118cb6368SRenaud Cerrato dev_info(&client->dev, 6218cb6368SRenaud Cerrato "low voltage detected, date/time is not reliable.\n"); 6318cb6368SRenaud Cerrato } 6418cb6368SRenaud Cerrato 6518cb6368SRenaud Cerrato dev_dbg(&client->dev, 6618cb6368SRenaud Cerrato "%s: raw data is cr1=%02x, cr2=%02x, cr3=%02x, " 6718cb6368SRenaud Cerrato "sec=%02x, min=%02x, hr=%02x, " 6818cb6368SRenaud Cerrato "mday=%02x, wday=%02x, mon=%02x, year=%02x\n", 6918cb6368SRenaud Cerrato __func__, 7018cb6368SRenaud Cerrato buf[0], buf[1], buf[2], 7118cb6368SRenaud Cerrato buf[3], buf[4], buf[5], 7218cb6368SRenaud Cerrato buf[6], buf[7], buf[8], buf[9]); 7318cb6368SRenaud Cerrato 7418cb6368SRenaud Cerrato 7518cb6368SRenaud Cerrato tm->tm_sec = bcd2bin(buf[PCF2127_REG_SC] & 0x7F); 7618cb6368SRenaud Cerrato tm->tm_min = bcd2bin(buf[PCF2127_REG_MN] & 0x7F); 7718cb6368SRenaud Cerrato tm->tm_hour = bcd2bin(buf[PCF2127_REG_HR] & 0x3F); /* rtc hr 0-23 */ 7818cb6368SRenaud Cerrato tm->tm_mday = bcd2bin(buf[PCF2127_REG_DM] & 0x3F); 7918cb6368SRenaud Cerrato tm->tm_wday = buf[PCF2127_REG_DW] & 0x07; 8018cb6368SRenaud Cerrato tm->tm_mon = bcd2bin(buf[PCF2127_REG_MO] & 0x1F) - 1; /* rtc mn 1-12 */ 8118cb6368SRenaud Cerrato tm->tm_year = bcd2bin(buf[PCF2127_REG_YR]); 8218cb6368SRenaud Cerrato if (tm->tm_year < 70) 8318cb6368SRenaud Cerrato tm->tm_year += 100; /* assume we are in 1970...2069 */ 8418cb6368SRenaud Cerrato 8518cb6368SRenaud Cerrato dev_dbg(&client->dev, "%s: tm is secs=%d, mins=%d, hours=%d, " 8618cb6368SRenaud Cerrato "mday=%d, mon=%d, year=%d, wday=%d\n", 8718cb6368SRenaud Cerrato __func__, 8818cb6368SRenaud Cerrato tm->tm_sec, tm->tm_min, tm->tm_hour, 8918cb6368SRenaud Cerrato tm->tm_mday, tm->tm_mon, tm->tm_year, tm->tm_wday); 9018cb6368SRenaud Cerrato 91821f51c4SAndrea Scian return rtc_valid_tm(tm); 9218cb6368SRenaud Cerrato } 9318cb6368SRenaud Cerrato 9418cb6368SRenaud Cerrato static int pcf2127_set_datetime(struct i2c_client *client, struct rtc_time *tm) 9518cb6368SRenaud Cerrato { 9618cb6368SRenaud Cerrato unsigned char buf[8]; 9718cb6368SRenaud Cerrato int i = 0, err; 9818cb6368SRenaud Cerrato 9918cb6368SRenaud Cerrato dev_dbg(&client->dev, "%s: secs=%d, mins=%d, hours=%d, " 10018cb6368SRenaud Cerrato "mday=%d, mon=%d, year=%d, wday=%d\n", 10118cb6368SRenaud Cerrato __func__, 10218cb6368SRenaud Cerrato tm->tm_sec, tm->tm_min, tm->tm_hour, 10318cb6368SRenaud Cerrato tm->tm_mday, tm->tm_mon, tm->tm_year, tm->tm_wday); 10418cb6368SRenaud Cerrato 10518cb6368SRenaud Cerrato /* start register address */ 10618cb6368SRenaud Cerrato buf[i++] = PCF2127_REG_SC; 10718cb6368SRenaud Cerrato 10818cb6368SRenaud Cerrato /* hours, minutes and seconds */ 10918cb6368SRenaud Cerrato buf[i++] = bin2bcd(tm->tm_sec); 11018cb6368SRenaud Cerrato buf[i++] = bin2bcd(tm->tm_min); 11118cb6368SRenaud Cerrato buf[i++] = bin2bcd(tm->tm_hour); 11218cb6368SRenaud Cerrato buf[i++] = bin2bcd(tm->tm_mday); 11318cb6368SRenaud Cerrato buf[i++] = tm->tm_wday & 0x07; 11418cb6368SRenaud Cerrato 11518cb6368SRenaud Cerrato /* month, 1 - 12 */ 11618cb6368SRenaud Cerrato buf[i++] = bin2bcd(tm->tm_mon + 1); 11718cb6368SRenaud Cerrato 11818cb6368SRenaud Cerrato /* year */ 11918cb6368SRenaud Cerrato buf[i++] = bin2bcd(tm->tm_year % 100); 12018cb6368SRenaud Cerrato 12118cb6368SRenaud Cerrato /* write register's data */ 12218cb6368SRenaud Cerrato err = i2c_master_send(client, buf, i); 12318cb6368SRenaud Cerrato if (err != i) { 12418cb6368SRenaud Cerrato dev_err(&client->dev, 12518cb6368SRenaud Cerrato "%s: err=%d", __func__, err); 12618cb6368SRenaud Cerrato return -EIO; 12718cb6368SRenaud Cerrato } 12818cb6368SRenaud Cerrato 12918cb6368SRenaud Cerrato return 0; 13018cb6368SRenaud Cerrato } 13118cb6368SRenaud Cerrato 13218cb6368SRenaud Cerrato #ifdef CONFIG_RTC_INTF_DEV 13318cb6368SRenaud Cerrato static int pcf2127_rtc_ioctl(struct device *dev, 13418cb6368SRenaud Cerrato unsigned int cmd, unsigned long arg) 13518cb6368SRenaud Cerrato { 13618cb6368SRenaud Cerrato struct pcf2127 *pcf2127 = i2c_get_clientdata(to_i2c_client(dev)); 13718cb6368SRenaud Cerrato 13818cb6368SRenaud Cerrato switch (cmd) { 13918cb6368SRenaud Cerrato case RTC_VL_READ: 14018cb6368SRenaud Cerrato if (pcf2127->voltage_low) 14118cb6368SRenaud Cerrato dev_info(dev, "low voltage detected, date/time is not reliable.\n"); 14218cb6368SRenaud Cerrato 14318cb6368SRenaud Cerrato if (copy_to_user((void __user *)arg, &pcf2127->voltage_low, 14418cb6368SRenaud Cerrato sizeof(int))) 14518cb6368SRenaud Cerrato return -EFAULT; 14618cb6368SRenaud Cerrato return 0; 14718cb6368SRenaud Cerrato default: 14818cb6368SRenaud Cerrato return -ENOIOCTLCMD; 14918cb6368SRenaud Cerrato } 15018cb6368SRenaud Cerrato } 15118cb6368SRenaud Cerrato #else 15218cb6368SRenaud Cerrato #define pcf2127_rtc_ioctl NULL 15318cb6368SRenaud Cerrato #endif 15418cb6368SRenaud Cerrato 15518cb6368SRenaud Cerrato static int pcf2127_rtc_read_time(struct device *dev, struct rtc_time *tm) 15618cb6368SRenaud Cerrato { 15718cb6368SRenaud Cerrato return pcf2127_get_datetime(to_i2c_client(dev), tm); 15818cb6368SRenaud Cerrato } 15918cb6368SRenaud Cerrato 16018cb6368SRenaud Cerrato static int pcf2127_rtc_set_time(struct device *dev, struct rtc_time *tm) 16118cb6368SRenaud Cerrato { 16218cb6368SRenaud Cerrato return pcf2127_set_datetime(to_i2c_client(dev), tm); 16318cb6368SRenaud Cerrato } 16418cb6368SRenaud Cerrato 16518cb6368SRenaud Cerrato static const struct rtc_class_ops pcf2127_rtc_ops = { 16618cb6368SRenaud Cerrato .ioctl = pcf2127_rtc_ioctl, 16718cb6368SRenaud Cerrato .read_time = pcf2127_rtc_read_time, 16818cb6368SRenaud Cerrato .set_time = pcf2127_rtc_set_time, 16918cb6368SRenaud Cerrato }; 17018cb6368SRenaud Cerrato 17118cb6368SRenaud Cerrato static int pcf2127_probe(struct i2c_client *client, 17218cb6368SRenaud Cerrato const struct i2c_device_id *id) 17318cb6368SRenaud Cerrato { 17418cb6368SRenaud Cerrato struct pcf2127 *pcf2127; 17518cb6368SRenaud Cerrato 17618cb6368SRenaud Cerrato dev_dbg(&client->dev, "%s\n", __func__); 17718cb6368SRenaud Cerrato 17818cb6368SRenaud Cerrato if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) 17918cb6368SRenaud Cerrato return -ENODEV; 18018cb6368SRenaud Cerrato 18118cb6368SRenaud Cerrato pcf2127 = devm_kzalloc(&client->dev, sizeof(struct pcf2127), 18218cb6368SRenaud Cerrato GFP_KERNEL); 18318cb6368SRenaud Cerrato if (!pcf2127) 18418cb6368SRenaud Cerrato return -ENOMEM; 18518cb6368SRenaud Cerrato 18618cb6368SRenaud Cerrato dev_info(&client->dev, "chip found, driver version " DRV_VERSION "\n"); 18718cb6368SRenaud Cerrato 18818cb6368SRenaud Cerrato i2c_set_clientdata(client, pcf2127); 18918cb6368SRenaud Cerrato 19018cb6368SRenaud Cerrato pcf2127->rtc = devm_rtc_device_register(&client->dev, 19118cb6368SRenaud Cerrato pcf2127_driver.driver.name, 19218cb6368SRenaud Cerrato &pcf2127_rtc_ops, THIS_MODULE); 19318cb6368SRenaud Cerrato 1947ab26cd1SDuan Jiong return PTR_ERR_OR_ZERO(pcf2127->rtc); 19518cb6368SRenaud Cerrato } 19618cb6368SRenaud Cerrato 19718cb6368SRenaud Cerrato static const struct i2c_device_id pcf2127_id[] = { 19818cb6368SRenaud Cerrato { "pcf2127", 0 }, 19918cb6368SRenaud Cerrato { } 20018cb6368SRenaud Cerrato }; 20118cb6368SRenaud Cerrato MODULE_DEVICE_TABLE(i2c, pcf2127_id); 20218cb6368SRenaud Cerrato 20318cb6368SRenaud Cerrato #ifdef CONFIG_OF 20418cb6368SRenaud Cerrato static const struct of_device_id pcf2127_of_match[] = { 20518cb6368SRenaud Cerrato { .compatible = "nxp,pcf2127" }, 20618cb6368SRenaud Cerrato {} 20718cb6368SRenaud Cerrato }; 20818cb6368SRenaud Cerrato MODULE_DEVICE_TABLE(of, pcf2127_of_match); 20918cb6368SRenaud Cerrato #endif 21018cb6368SRenaud Cerrato 21118cb6368SRenaud Cerrato static struct i2c_driver pcf2127_driver = { 21218cb6368SRenaud Cerrato .driver = { 21318cb6368SRenaud Cerrato .name = "rtc-pcf2127", 21418cb6368SRenaud Cerrato .owner = THIS_MODULE, 21518cb6368SRenaud Cerrato .of_match_table = of_match_ptr(pcf2127_of_match), 21618cb6368SRenaud Cerrato }, 21718cb6368SRenaud Cerrato .probe = pcf2127_probe, 21818cb6368SRenaud Cerrato .id_table = pcf2127_id, 21918cb6368SRenaud Cerrato }; 22018cb6368SRenaud Cerrato 22118cb6368SRenaud Cerrato module_i2c_driver(pcf2127_driver); 22218cb6368SRenaud Cerrato 22318cb6368SRenaud Cerrato MODULE_AUTHOR("Renaud Cerrato <r.cerrato@til-technologies.fr>"); 22418cb6368SRenaud Cerrato MODULE_DESCRIPTION("NXP PCF2127 RTC driver"); 22518cb6368SRenaud Cerrato MODULE_LICENSE("GPL"); 22618cb6368SRenaud Cerrato MODULE_VERSION(DRV_VERSION); 227