1 /* 2 * drivers/rtc/rtc-pcf85363.c 3 * 4 * Driver for NXP PCF85363 real-time clock. 5 * 6 * Copyright (C) 2017 Eric Nelson 7 * 8 * This program is free software; you can redistribute it and/or modify 9 * it under the terms of the GNU General Public License version 2 as 10 * published by the Free Software Foundation. 11 * 12 * Based loosely on rtc-8583 by Russell King, Wolfram Sang and Juergen Beisert 13 */ 14 #include <linux/module.h> 15 #include <linux/i2c.h> 16 #include <linux/slab.h> 17 #include <linux/rtc.h> 18 #include <linux/init.h> 19 #include <linux/err.h> 20 #include <linux/errno.h> 21 #include <linux/bcd.h> 22 #include <linux/of.h> 23 #include <linux/of_device.h> 24 #include <linux/regmap.h> 25 26 /* 27 * Date/Time registers 28 */ 29 #define DT_100THS 0x00 30 #define DT_SECS 0x01 31 #define DT_MINUTES 0x02 32 #define DT_HOURS 0x03 33 #define DT_DAYS 0x04 34 #define DT_WEEKDAYS 0x05 35 #define DT_MONTHS 0x06 36 #define DT_YEARS 0x07 37 38 /* 39 * Alarm registers 40 */ 41 #define DT_SECOND_ALM1 0x08 42 #define DT_MINUTE_ALM1 0x09 43 #define DT_HOUR_ALM1 0x0a 44 #define DT_DAY_ALM1 0x0b 45 #define DT_MONTH_ALM1 0x0c 46 #define DT_MINUTE_ALM2 0x0d 47 #define DT_HOUR_ALM2 0x0e 48 #define DT_WEEKDAY_ALM2 0x0f 49 #define DT_ALARM_EN 0x10 50 51 /* 52 * Time stamp registers 53 */ 54 #define DT_TIMESTAMP1 0x11 55 #define DT_TIMESTAMP2 0x17 56 #define DT_TIMESTAMP3 0x1d 57 #define DT_TS_MODE 0x23 58 59 /* 60 * control registers 61 */ 62 #define CTRL_OFFSET 0x24 63 #define CTRL_OSCILLATOR 0x25 64 #define CTRL_BATTERY 0x26 65 #define CTRL_PIN_IO 0x27 66 #define CTRL_FUNCTION 0x28 67 #define CTRL_INTA_EN 0x29 68 #define CTRL_INTB_EN 0x2a 69 #define CTRL_FLAGS 0x2b 70 #define CTRL_RAMBYTE 0x2c 71 #define CTRL_WDOG 0x2d 72 #define CTRL_STOP_EN 0x2e 73 #define CTRL_RESETS 0x2f 74 #define CTRL_RAM 0x40 75 76 #define NVRAM_SIZE 0x40 77 78 static struct i2c_driver pcf85363_driver; 79 80 struct pcf85363 { 81 struct device *dev; 82 struct rtc_device *rtc; 83 struct nvmem_config nvmem_cfg; 84 struct regmap *regmap; 85 }; 86 87 static int pcf85363_rtc_read_time(struct device *dev, struct rtc_time *tm) 88 { 89 struct pcf85363 *pcf85363 = dev_get_drvdata(dev); 90 unsigned char buf[DT_YEARS + 1]; 91 int ret, len = sizeof(buf); 92 93 /* read the RTC date and time registers all at once */ 94 ret = regmap_bulk_read(pcf85363->regmap, DT_100THS, buf, len); 95 if (ret) { 96 dev_err(dev, "%s: error %d\n", __func__, ret); 97 return ret; 98 } 99 100 tm->tm_year = bcd2bin(buf[DT_YEARS]); 101 /* adjust for 1900 base of rtc_time */ 102 tm->tm_year += 100; 103 104 tm->tm_wday = buf[DT_WEEKDAYS] & 7; 105 buf[DT_SECS] &= 0x7F; 106 tm->tm_sec = bcd2bin(buf[DT_SECS]); 107 buf[DT_MINUTES] &= 0x7F; 108 tm->tm_min = bcd2bin(buf[DT_MINUTES]); 109 tm->tm_hour = bcd2bin(buf[DT_HOURS]); 110 tm->tm_mday = bcd2bin(buf[DT_DAYS]); 111 tm->tm_mon = bcd2bin(buf[DT_MONTHS]) - 1; 112 113 return 0; 114 } 115 116 static int pcf85363_rtc_set_time(struct device *dev, struct rtc_time *tm) 117 { 118 struct pcf85363 *pcf85363 = dev_get_drvdata(dev); 119 unsigned char buf[DT_YEARS + 1]; 120 int len = sizeof(buf); 121 122 buf[DT_100THS] = 0; 123 buf[DT_SECS] = bin2bcd(tm->tm_sec); 124 buf[DT_MINUTES] = bin2bcd(tm->tm_min); 125 buf[DT_HOURS] = bin2bcd(tm->tm_hour); 126 buf[DT_DAYS] = bin2bcd(tm->tm_mday); 127 buf[DT_WEEKDAYS] = tm->tm_wday; 128 buf[DT_MONTHS] = bin2bcd(tm->tm_mon + 1); 129 buf[DT_YEARS] = bin2bcd(tm->tm_year % 100); 130 131 return regmap_bulk_write(pcf85363->regmap, DT_100THS, 132 buf, len); 133 } 134 135 static const struct rtc_class_ops rtc_ops = { 136 .read_time = pcf85363_rtc_read_time, 137 .set_time = pcf85363_rtc_set_time, 138 }; 139 140 static int pcf85363_nvram_read(void *priv, unsigned int offset, void *val, 141 size_t bytes) 142 { 143 struct pcf85363 *pcf85363 = priv; 144 145 return regmap_bulk_read(pcf85363->regmap, CTRL_RAM + offset, 146 val, bytes); 147 } 148 149 static int pcf85363_nvram_write(void *priv, unsigned int offset, void *val, 150 size_t bytes) 151 { 152 struct pcf85363 *pcf85363 = priv; 153 154 return regmap_bulk_write(pcf85363->regmap, CTRL_RAM + offset, 155 val, bytes); 156 } 157 158 static const struct regmap_config regmap_config = { 159 .reg_bits = 8, 160 .val_bits = 8, 161 }; 162 163 static int pcf85363_probe(struct i2c_client *client, 164 const struct i2c_device_id *id) 165 { 166 struct pcf85363 *pcf85363; 167 168 if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) 169 return -ENODEV; 170 171 pcf85363 = devm_kzalloc(&client->dev, sizeof(struct pcf85363), 172 GFP_KERNEL); 173 if (!pcf85363) 174 return -ENOMEM; 175 176 pcf85363->regmap = devm_regmap_init_i2c(client, ®map_config); 177 if (IS_ERR(pcf85363->regmap)) { 178 dev_err(&client->dev, "regmap allocation failed\n"); 179 return PTR_ERR(pcf85363->regmap); 180 } 181 182 pcf85363->dev = &client->dev; 183 i2c_set_clientdata(client, pcf85363); 184 185 pcf85363->rtc = devm_rtc_allocate_device(pcf85363->dev); 186 if (IS_ERR(pcf85363->rtc)) 187 return PTR_ERR(pcf85363->rtc); 188 189 pcf85363->nvmem_cfg.name = "pcf85363-"; 190 pcf85363->nvmem_cfg.word_size = 1; 191 pcf85363->nvmem_cfg.stride = 1; 192 pcf85363->nvmem_cfg.size = NVRAM_SIZE; 193 pcf85363->nvmem_cfg.reg_read = pcf85363_nvram_read; 194 pcf85363->nvmem_cfg.reg_write = pcf85363_nvram_write; 195 pcf85363->nvmem_cfg.priv = pcf85363; 196 pcf85363->rtc->nvmem_config = &pcf85363->nvmem_cfg; 197 pcf85363->rtc->ops = &rtc_ops; 198 199 return rtc_register_device(pcf85363->rtc); 200 } 201 202 static const struct of_device_id dev_ids[] = { 203 { .compatible = "nxp,pcf85363" }, 204 {} 205 }; 206 MODULE_DEVICE_TABLE(of, dev_ids); 207 208 static struct i2c_driver pcf85363_driver = { 209 .driver = { 210 .name = "pcf85363", 211 .of_match_table = of_match_ptr(dev_ids), 212 }, 213 .probe = pcf85363_probe, 214 }; 215 216 module_i2c_driver(pcf85363_driver); 217 218 MODULE_AUTHOR("Eric Nelson"); 219 MODULE_DESCRIPTION("pcf85363 I2C RTC driver"); 220 MODULE_LICENSE("GPL"); 221