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> 22907b3262SAkinobu Mita #include <linux/regmap.h> 2318cb6368SRenaud Cerrato 2418cb6368SRenaud Cerrato #define PCF2127_REG_CTRL1 (0x00) /* Control Register 1 */ 2518cb6368SRenaud Cerrato #define PCF2127_REG_CTRL2 (0x01) /* Control Register 2 */ 26f97cfddcSUwe Kleine-König 2718cb6368SRenaud Cerrato #define PCF2127_REG_CTRL3 (0x02) /* Control Register 3 */ 28f97cfddcSUwe Kleine-König #define PCF2127_REG_CTRL3_BLF BIT(2) 29f97cfddcSUwe Kleine-König 3018cb6368SRenaud Cerrato #define PCF2127_REG_SC (0x03) /* datetime */ 3118cb6368SRenaud Cerrato #define PCF2127_REG_MN (0x04) 3218cb6368SRenaud Cerrato #define PCF2127_REG_HR (0x05) 3318cb6368SRenaud Cerrato #define PCF2127_REG_DM (0x06) 3418cb6368SRenaud Cerrato #define PCF2127_REG_DW (0x07) 3518cb6368SRenaud Cerrato #define PCF2127_REG_MO (0x08) 3618cb6368SRenaud Cerrato #define PCF2127_REG_YR (0x09) 3718cb6368SRenaud Cerrato 38653ebd75SAndrea Scian #define PCF2127_OSF BIT(7) /* Oscillator Fail flag */ 39653ebd75SAndrea Scian 4018cb6368SRenaud Cerrato struct pcf2127 { 4118cb6368SRenaud Cerrato struct rtc_device *rtc; 42907b3262SAkinobu Mita struct regmap *regmap; 4318cb6368SRenaud Cerrato }; 4418cb6368SRenaud Cerrato 4518cb6368SRenaud Cerrato /* 4618cb6368SRenaud Cerrato * In the routines that deal directly with the pcf2127 hardware, we use 4718cb6368SRenaud Cerrato * rtc_time -- month 0-11, hour 0-23, yr = calendar year-epoch. 4818cb6368SRenaud Cerrato */ 49907b3262SAkinobu Mita static int pcf2127_rtc_read_time(struct device *dev, struct rtc_time *tm) 5018cb6368SRenaud Cerrato { 51907b3262SAkinobu Mita struct pcf2127 *pcf2127 = dev_get_drvdata(dev); 52907b3262SAkinobu Mita unsigned char buf[10]; 53907b3262SAkinobu Mita int ret; 5418cb6368SRenaud Cerrato 55907b3262SAkinobu Mita ret = regmap_bulk_read(pcf2127->regmap, PCF2127_REG_CTRL1, buf, 56907b3262SAkinobu Mita sizeof(buf)); 57907b3262SAkinobu Mita if (ret) { 58907b3262SAkinobu Mita dev_err(dev, "%s: read error\n", __func__); 59907b3262SAkinobu Mita return ret; 6018cb6368SRenaud Cerrato } 6118cb6368SRenaud Cerrato 62f97cfddcSUwe Kleine-König if (buf[PCF2127_REG_CTRL3] & PCF2127_REG_CTRL3_BLF) 63907b3262SAkinobu Mita dev_info(dev, 64653ebd75SAndrea Scian "low voltage detected, check/replace RTC battery.\n"); 65653ebd75SAndrea Scian 66653ebd75SAndrea Scian if (buf[PCF2127_REG_SC] & PCF2127_OSF) { 67653ebd75SAndrea Scian /* 68653ebd75SAndrea Scian * no need clear the flag here, 69653ebd75SAndrea Scian * it will be cleared once the new date is saved 70653ebd75SAndrea Scian */ 71907b3262SAkinobu Mita dev_warn(dev, 72653ebd75SAndrea Scian "oscillator stop detected, date/time is not reliable\n"); 73653ebd75SAndrea Scian return -EINVAL; 7418cb6368SRenaud Cerrato } 7518cb6368SRenaud Cerrato 76907b3262SAkinobu Mita dev_dbg(dev, 7718cb6368SRenaud Cerrato "%s: raw data is cr1=%02x, cr2=%02x, cr3=%02x, " 7818cb6368SRenaud Cerrato "sec=%02x, min=%02x, hr=%02x, " 7918cb6368SRenaud Cerrato "mday=%02x, wday=%02x, mon=%02x, year=%02x\n", 8018cb6368SRenaud Cerrato __func__, 8118cb6368SRenaud Cerrato buf[0], buf[1], buf[2], 8218cb6368SRenaud Cerrato buf[3], buf[4], buf[5], 8318cb6368SRenaud Cerrato buf[6], buf[7], buf[8], buf[9]); 8418cb6368SRenaud Cerrato 8518cb6368SRenaud Cerrato 8618cb6368SRenaud Cerrato tm->tm_sec = bcd2bin(buf[PCF2127_REG_SC] & 0x7F); 8718cb6368SRenaud Cerrato tm->tm_min = bcd2bin(buf[PCF2127_REG_MN] & 0x7F); 8818cb6368SRenaud Cerrato tm->tm_hour = bcd2bin(buf[PCF2127_REG_HR] & 0x3F); /* rtc hr 0-23 */ 8918cb6368SRenaud Cerrato tm->tm_mday = bcd2bin(buf[PCF2127_REG_DM] & 0x3F); 9018cb6368SRenaud Cerrato tm->tm_wday = buf[PCF2127_REG_DW] & 0x07; 9118cb6368SRenaud Cerrato tm->tm_mon = bcd2bin(buf[PCF2127_REG_MO] & 0x1F) - 1; /* rtc mn 1-12 */ 9218cb6368SRenaud Cerrato tm->tm_year = bcd2bin(buf[PCF2127_REG_YR]); 9318cb6368SRenaud Cerrato if (tm->tm_year < 70) 9418cb6368SRenaud Cerrato tm->tm_year += 100; /* assume we are in 1970...2069 */ 9518cb6368SRenaud Cerrato 96907b3262SAkinobu Mita dev_dbg(dev, "%s: tm is secs=%d, mins=%d, hours=%d, " 9718cb6368SRenaud Cerrato "mday=%d, mon=%d, year=%d, wday=%d\n", 9818cb6368SRenaud Cerrato __func__, 9918cb6368SRenaud Cerrato tm->tm_sec, tm->tm_min, tm->tm_hour, 10018cb6368SRenaud Cerrato tm->tm_mday, tm->tm_mon, tm->tm_year, tm->tm_wday); 10118cb6368SRenaud Cerrato 102821f51c4SAndrea Scian return rtc_valid_tm(tm); 10318cb6368SRenaud Cerrato } 10418cb6368SRenaud Cerrato 105907b3262SAkinobu Mita static int pcf2127_rtc_set_time(struct device *dev, struct rtc_time *tm) 10618cb6368SRenaud Cerrato { 107907b3262SAkinobu Mita struct pcf2127 *pcf2127 = dev_get_drvdata(dev); 108907b3262SAkinobu Mita unsigned char buf[7]; 10918cb6368SRenaud Cerrato int i = 0, err; 11018cb6368SRenaud Cerrato 111907b3262SAkinobu Mita dev_dbg(dev, "%s: secs=%d, mins=%d, hours=%d, " 11218cb6368SRenaud Cerrato "mday=%d, mon=%d, year=%d, wday=%d\n", 11318cb6368SRenaud Cerrato __func__, 11418cb6368SRenaud Cerrato tm->tm_sec, tm->tm_min, tm->tm_hour, 11518cb6368SRenaud Cerrato tm->tm_mday, tm->tm_mon, tm->tm_year, tm->tm_wday); 11618cb6368SRenaud Cerrato 11718cb6368SRenaud Cerrato /* hours, minutes and seconds */ 118653ebd75SAndrea Scian buf[i++] = bin2bcd(tm->tm_sec); /* this will also clear OSF flag */ 11918cb6368SRenaud Cerrato buf[i++] = bin2bcd(tm->tm_min); 12018cb6368SRenaud Cerrato buf[i++] = bin2bcd(tm->tm_hour); 12118cb6368SRenaud Cerrato buf[i++] = bin2bcd(tm->tm_mday); 12218cb6368SRenaud Cerrato buf[i++] = tm->tm_wday & 0x07; 12318cb6368SRenaud Cerrato 12418cb6368SRenaud Cerrato /* month, 1 - 12 */ 12518cb6368SRenaud Cerrato buf[i++] = bin2bcd(tm->tm_mon + 1); 12618cb6368SRenaud Cerrato 12718cb6368SRenaud Cerrato /* year */ 12818cb6368SRenaud Cerrato buf[i++] = bin2bcd(tm->tm_year % 100); 12918cb6368SRenaud Cerrato 13018cb6368SRenaud Cerrato /* write register's data */ 131907b3262SAkinobu Mita err = regmap_bulk_write(pcf2127->regmap, PCF2127_REG_SC, buf, i); 132907b3262SAkinobu Mita if (err) { 133907b3262SAkinobu Mita dev_err(dev, 13418cb6368SRenaud Cerrato "%s: err=%d", __func__, err); 135907b3262SAkinobu Mita return err; 13618cb6368SRenaud Cerrato } 13718cb6368SRenaud Cerrato 13818cb6368SRenaud Cerrato return 0; 13918cb6368SRenaud Cerrato } 14018cb6368SRenaud Cerrato 14118cb6368SRenaud Cerrato #ifdef CONFIG_RTC_INTF_DEV 14218cb6368SRenaud Cerrato static int pcf2127_rtc_ioctl(struct device *dev, 14318cb6368SRenaud Cerrato unsigned int cmd, unsigned long arg) 14418cb6368SRenaud Cerrato { 145907b3262SAkinobu Mita struct pcf2127 *pcf2127 = dev_get_drvdata(dev); 146f97cfddcSUwe Kleine-König int touser; 147f97cfddcSUwe Kleine-König int ret; 14818cb6368SRenaud Cerrato 14918cb6368SRenaud Cerrato switch (cmd) { 15018cb6368SRenaud Cerrato case RTC_VL_READ: 151907b3262SAkinobu Mita ret = regmap_read(pcf2127->regmap, PCF2127_REG_CTRL3, &touser); 152907b3262SAkinobu Mita if (ret) 153f97cfddcSUwe Kleine-König return ret; 15418cb6368SRenaud Cerrato 155907b3262SAkinobu Mita touser = touser & PCF2127_REG_CTRL3_BLF ? 1 : 0; 156f97cfddcSUwe Kleine-König 157f97cfddcSUwe Kleine-König if (copy_to_user((void __user *)arg, &touser, sizeof(int))) 15818cb6368SRenaud Cerrato return -EFAULT; 15918cb6368SRenaud Cerrato return 0; 16018cb6368SRenaud Cerrato default: 16118cb6368SRenaud Cerrato return -ENOIOCTLCMD; 16218cb6368SRenaud Cerrato } 16318cb6368SRenaud Cerrato } 16418cb6368SRenaud Cerrato #else 16518cb6368SRenaud Cerrato #define pcf2127_rtc_ioctl NULL 16618cb6368SRenaud Cerrato #endif 16718cb6368SRenaud Cerrato 16818cb6368SRenaud Cerrato static const struct rtc_class_ops pcf2127_rtc_ops = { 16918cb6368SRenaud Cerrato .ioctl = pcf2127_rtc_ioctl, 17018cb6368SRenaud Cerrato .read_time = pcf2127_rtc_read_time, 17118cb6368SRenaud Cerrato .set_time = pcf2127_rtc_set_time, 17218cb6368SRenaud Cerrato }; 17318cb6368SRenaud Cerrato 174907b3262SAkinobu Mita static int pcf2127_probe(struct device *dev, struct regmap *regmap, 175907b3262SAkinobu Mita const char *name) 17618cb6368SRenaud Cerrato { 17718cb6368SRenaud Cerrato struct pcf2127 *pcf2127; 17818cb6368SRenaud Cerrato 179907b3262SAkinobu Mita dev_dbg(dev, "%s\n", __func__); 18018cb6368SRenaud Cerrato 181907b3262SAkinobu Mita pcf2127 = devm_kzalloc(dev, sizeof(*pcf2127), GFP_KERNEL); 18218cb6368SRenaud Cerrato if (!pcf2127) 18318cb6368SRenaud Cerrato return -ENOMEM; 18418cb6368SRenaud Cerrato 185907b3262SAkinobu Mita pcf2127->regmap = regmap; 18618cb6368SRenaud Cerrato 187907b3262SAkinobu Mita dev_set_drvdata(dev, pcf2127); 188907b3262SAkinobu Mita 189907b3262SAkinobu Mita pcf2127->rtc = devm_rtc_device_register(dev, name, &pcf2127_rtc_ops, 190907b3262SAkinobu Mita THIS_MODULE); 19118cb6368SRenaud Cerrato 1927ab26cd1SDuan Jiong return PTR_ERR_OR_ZERO(pcf2127->rtc); 19318cb6368SRenaud Cerrato } 19418cb6368SRenaud Cerrato 19518cb6368SRenaud Cerrato #ifdef CONFIG_OF 19618cb6368SRenaud Cerrato static const struct of_device_id pcf2127_of_match[] = { 19718cb6368SRenaud Cerrato { .compatible = "nxp,pcf2127" }, 19818cb6368SRenaud Cerrato {} 19918cb6368SRenaud Cerrato }; 20018cb6368SRenaud Cerrato MODULE_DEVICE_TABLE(of, pcf2127_of_match); 20118cb6368SRenaud Cerrato #endif 20218cb6368SRenaud Cerrato 203907b3262SAkinobu Mita static int pcf2127_i2c_write(void *context, const void *data, size_t count) 204907b3262SAkinobu Mita { 205907b3262SAkinobu Mita struct device *dev = context; 206907b3262SAkinobu Mita struct i2c_client *client = to_i2c_client(dev); 207907b3262SAkinobu Mita int ret; 208907b3262SAkinobu Mita 209907b3262SAkinobu Mita ret = i2c_master_send(client, data, count); 210907b3262SAkinobu Mita if (ret != count) 211907b3262SAkinobu Mita return ret < 0 ? ret : -EIO; 212907b3262SAkinobu Mita 213907b3262SAkinobu Mita return 0; 214907b3262SAkinobu Mita } 215907b3262SAkinobu Mita 216907b3262SAkinobu Mita static int pcf2127_i2c_gather_write(void *context, 217907b3262SAkinobu Mita const void *reg, size_t reg_size, 218907b3262SAkinobu Mita const void *val, size_t val_size) 219907b3262SAkinobu Mita { 220907b3262SAkinobu Mita struct device *dev = context; 221907b3262SAkinobu Mita struct i2c_client *client = to_i2c_client(dev); 222907b3262SAkinobu Mita int ret; 223907b3262SAkinobu Mita void *buf; 224907b3262SAkinobu Mita 225907b3262SAkinobu Mita if (WARN_ON(reg_size != 1)) 226907b3262SAkinobu Mita return -EINVAL; 227907b3262SAkinobu Mita 228907b3262SAkinobu Mita buf = kmalloc(val_size + 1, GFP_KERNEL); 229907b3262SAkinobu Mita if (!buf) 230907b3262SAkinobu Mita return -ENOMEM; 231907b3262SAkinobu Mita 232907b3262SAkinobu Mita memcpy(buf, reg, 1); 233907b3262SAkinobu Mita memcpy(buf + 1, val, val_size); 234907b3262SAkinobu Mita 235907b3262SAkinobu Mita ret = i2c_master_send(client, buf, val_size + 1); 236907b3262SAkinobu Mita if (ret != val_size + 1) 237907b3262SAkinobu Mita return ret < 0 ? ret : -EIO; 238907b3262SAkinobu Mita 239907b3262SAkinobu Mita return 0; 240907b3262SAkinobu Mita } 241907b3262SAkinobu Mita 242907b3262SAkinobu Mita static int pcf2127_i2c_read(void *context, const void *reg, size_t reg_size, 243907b3262SAkinobu Mita void *val, size_t val_size) 244907b3262SAkinobu Mita { 245907b3262SAkinobu Mita struct device *dev = context; 246907b3262SAkinobu Mita struct i2c_client *client = to_i2c_client(dev); 247907b3262SAkinobu Mita int ret; 248907b3262SAkinobu Mita 249907b3262SAkinobu Mita if (WARN_ON(reg_size != 1)) 250907b3262SAkinobu Mita return -EINVAL; 251907b3262SAkinobu Mita 252907b3262SAkinobu Mita ret = i2c_master_send(client, reg, 1); 253907b3262SAkinobu Mita if (ret != 1) 254907b3262SAkinobu Mita return ret < 0 ? ret : -EIO; 255907b3262SAkinobu Mita 256907b3262SAkinobu Mita ret = i2c_master_recv(client, val, val_size); 257907b3262SAkinobu Mita if (ret != val_size) 258907b3262SAkinobu Mita return ret < 0 ? ret : -EIO; 259907b3262SAkinobu Mita 260907b3262SAkinobu Mita return 0; 261907b3262SAkinobu Mita } 262907b3262SAkinobu Mita 263907b3262SAkinobu Mita /* 264907b3262SAkinobu Mita * The reason we need this custom regmap_bus instead of using regmap_init_i2c() 265907b3262SAkinobu Mita * is that the STOP condition is required between set register address and 266907b3262SAkinobu Mita * read register data when reading from registers. 267907b3262SAkinobu Mita */ 268907b3262SAkinobu Mita static const struct regmap_bus pcf2127_i2c_regmap = { 269907b3262SAkinobu Mita .write = pcf2127_i2c_write, 270907b3262SAkinobu Mita .gather_write = pcf2127_i2c_gather_write, 271907b3262SAkinobu Mita .read = pcf2127_i2c_read, 27218cb6368SRenaud Cerrato }; 27318cb6368SRenaud Cerrato 274907b3262SAkinobu Mita static struct i2c_driver pcf2127_i2c_driver; 275907b3262SAkinobu Mita 276907b3262SAkinobu Mita static int pcf2127_i2c_probe(struct i2c_client *client, 277907b3262SAkinobu Mita const struct i2c_device_id *id) 278907b3262SAkinobu Mita { 279907b3262SAkinobu Mita struct regmap *regmap; 280907b3262SAkinobu Mita static const struct regmap_config config = { 281907b3262SAkinobu Mita .reg_bits = 8, 282907b3262SAkinobu Mita .val_bits = 8, 283907b3262SAkinobu Mita }; 284907b3262SAkinobu Mita 285907b3262SAkinobu Mita if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) 286907b3262SAkinobu Mita return -ENODEV; 287907b3262SAkinobu Mita 288907b3262SAkinobu Mita regmap = devm_regmap_init(&client->dev, &pcf2127_i2c_regmap, 289907b3262SAkinobu Mita &client->dev, &config); 290907b3262SAkinobu Mita if (IS_ERR(regmap)) { 291907b3262SAkinobu Mita dev_err(&client->dev, "%s: regmap allocation failed: %ld\n", 292907b3262SAkinobu Mita __func__, PTR_ERR(regmap)); 293907b3262SAkinobu Mita return PTR_ERR(regmap); 294907b3262SAkinobu Mita } 295907b3262SAkinobu Mita 296907b3262SAkinobu Mita return pcf2127_probe(&client->dev, regmap, 297907b3262SAkinobu Mita pcf2127_i2c_driver.driver.name); 298907b3262SAkinobu Mita } 299907b3262SAkinobu Mita 300907b3262SAkinobu Mita static const struct i2c_device_id pcf2127_i2c_id[] = { 301907b3262SAkinobu Mita { "pcf2127", 0 }, 302907b3262SAkinobu Mita { } 303907b3262SAkinobu Mita }; 304907b3262SAkinobu Mita MODULE_DEVICE_TABLE(i2c, pcf2127_i2c_id); 305907b3262SAkinobu Mita 306907b3262SAkinobu Mita static struct i2c_driver pcf2127_i2c_driver = { 307907b3262SAkinobu Mita .driver = { 308907b3262SAkinobu Mita .name = "rtc-pcf2127-i2c", 309907b3262SAkinobu Mita .of_match_table = of_match_ptr(pcf2127_of_match), 310907b3262SAkinobu Mita }, 311907b3262SAkinobu Mita .probe = pcf2127_i2c_probe, 312907b3262SAkinobu Mita .id_table = pcf2127_i2c_id, 313907b3262SAkinobu Mita }; 314907b3262SAkinobu Mita module_i2c_driver(pcf2127_i2c_driver); 31518cb6368SRenaud Cerrato 31618cb6368SRenaud Cerrato MODULE_AUTHOR("Renaud Cerrato <r.cerrato@til-technologies.fr>"); 31718cb6368SRenaud Cerrato MODULE_DESCRIPTION("NXP PCF2127 RTC driver"); 3184d8318bcSUwe Kleine-König MODULE_LICENSE("GPL v2"); 319