1edf1aaa3SAlessandro Zummo /* 2edf1aaa3SAlessandro Zummo * An rtc/i2c driver for the Dallas DS1672 33903586aSAlessandro Zummo * Copyright 2005-06 Tower Technologies 43903586aSAlessandro Zummo * 53903586aSAlessandro Zummo * Author: Alessandro Zummo <a.zummo@towertech.it> 6edf1aaa3SAlessandro Zummo * 7edf1aaa3SAlessandro Zummo * This program is free software; you can redistribute it and/or modify 8edf1aaa3SAlessandro Zummo * it under the terms of the GNU General Public License version 2 as 9edf1aaa3SAlessandro Zummo * published by the Free Software Foundation. 10edf1aaa3SAlessandro Zummo */ 11edf1aaa3SAlessandro Zummo 12edf1aaa3SAlessandro Zummo #include <linux/module.h> 13edf1aaa3SAlessandro Zummo #include <linux/i2c.h> 14edf1aaa3SAlessandro Zummo #include <linux/rtc.h> 15edf1aaa3SAlessandro Zummo 163903586aSAlessandro Zummo #define DRV_VERSION "0.3" 17edf1aaa3SAlessandro Zummo 18edf1aaa3SAlessandro Zummo /* Addresses to scan: none. This chip cannot be detected. */ 19edf1aaa3SAlessandro Zummo static unsigned short normal_i2c[] = { I2C_CLIENT_END }; 20edf1aaa3SAlessandro Zummo 21edf1aaa3SAlessandro Zummo /* Insmod parameters */ 22edf1aaa3SAlessandro Zummo I2C_CLIENT_INSMOD; 23edf1aaa3SAlessandro Zummo 24edf1aaa3SAlessandro Zummo /* Registers */ 25edf1aaa3SAlessandro Zummo 26edf1aaa3SAlessandro Zummo #define DS1672_REG_CNT_BASE 0 27edf1aaa3SAlessandro Zummo #define DS1672_REG_CONTROL 4 28edf1aaa3SAlessandro Zummo #define DS1672_REG_TRICKLE 5 29edf1aaa3SAlessandro Zummo 303903586aSAlessandro Zummo #define DS1672_REG_CONTROL_EOSC 0x80 31edf1aaa3SAlessandro Zummo 32edf1aaa3SAlessandro Zummo /* Prototypes */ 33edf1aaa3SAlessandro Zummo static int ds1672_probe(struct i2c_adapter *adapter, int address, int kind); 34edf1aaa3SAlessandro Zummo 35edf1aaa3SAlessandro Zummo /* 36edf1aaa3SAlessandro Zummo * In the routines that deal directly with the ds1672 hardware, we use 37edf1aaa3SAlessandro Zummo * rtc_time -- month 0-11, hour 0-23, yr = calendar year-epoch 38edf1aaa3SAlessandro Zummo * Epoch is initialized as 2000. Time is set to UTC. 39edf1aaa3SAlessandro Zummo */ 40edf1aaa3SAlessandro Zummo static int ds1672_get_datetime(struct i2c_client *client, struct rtc_time *tm) 41edf1aaa3SAlessandro Zummo { 42edf1aaa3SAlessandro Zummo unsigned long time; 43edf1aaa3SAlessandro Zummo unsigned char addr = DS1672_REG_CNT_BASE; 44edf1aaa3SAlessandro Zummo unsigned char buf[4]; 45edf1aaa3SAlessandro Zummo 46edf1aaa3SAlessandro Zummo struct i2c_msg msgs[] = { 47edf1aaa3SAlessandro Zummo { client->addr, 0, 1, &addr }, /* setup read ptr */ 48edf1aaa3SAlessandro Zummo { client->addr, I2C_M_RD, 4, buf }, /* read date */ 49edf1aaa3SAlessandro Zummo }; 50edf1aaa3SAlessandro Zummo 51edf1aaa3SAlessandro Zummo /* read date registers */ 52edf1aaa3SAlessandro Zummo if ((i2c_transfer(client->adapter, &msgs[0], 2)) != 2) { 53edf1aaa3SAlessandro Zummo dev_err(&client->dev, "%s: read error\n", __FUNCTION__); 54edf1aaa3SAlessandro Zummo return -EIO; 55edf1aaa3SAlessandro Zummo } 56edf1aaa3SAlessandro Zummo 57edf1aaa3SAlessandro Zummo dev_dbg(&client->dev, 58edf1aaa3SAlessandro Zummo "%s: raw read data - counters=%02x,%02x,%02x,%02x\n" 593903586aSAlessandro Zummo __FUNCTION__, buf[0], buf[1], buf[2], buf[3]); 60edf1aaa3SAlessandro Zummo 61edf1aaa3SAlessandro Zummo time = (buf[3] << 24) | (buf[2] << 16) | (buf[1] << 8) | buf[0]; 62edf1aaa3SAlessandro Zummo 63edf1aaa3SAlessandro Zummo rtc_time_to_tm(time, tm); 64edf1aaa3SAlessandro Zummo 65edf1aaa3SAlessandro Zummo dev_dbg(&client->dev, "%s: tm is secs=%d, mins=%d, hours=%d, " 66edf1aaa3SAlessandro Zummo "mday=%d, mon=%d, year=%d, wday=%d\n", 673903586aSAlessandro Zummo __FUNCTION__, tm->tm_sec, tm->tm_min, tm->tm_hour, 68edf1aaa3SAlessandro Zummo tm->tm_mday, tm->tm_mon, tm->tm_year, tm->tm_wday); 69edf1aaa3SAlessandro Zummo 70edf1aaa3SAlessandro Zummo return 0; 71edf1aaa3SAlessandro Zummo } 72edf1aaa3SAlessandro Zummo 73edf1aaa3SAlessandro Zummo static int ds1672_set_mmss(struct i2c_client *client, unsigned long secs) 74edf1aaa3SAlessandro Zummo { 75edf1aaa3SAlessandro Zummo int xfer; 768a95b252SKumar Gala unsigned char buf[6]; 77edf1aaa3SAlessandro Zummo 78edf1aaa3SAlessandro Zummo buf[0] = DS1672_REG_CNT_BASE; 79edf1aaa3SAlessandro Zummo buf[1] = secs & 0x000000FF; 80edf1aaa3SAlessandro Zummo buf[2] = (secs & 0x0000FF00) >> 8; 81edf1aaa3SAlessandro Zummo buf[3] = (secs & 0x00FF0000) >> 16; 82edf1aaa3SAlessandro Zummo buf[4] = (secs & 0xFF000000) >> 24; 838a95b252SKumar Gala buf[5] = 0; /* set control reg to enable counting */ 84edf1aaa3SAlessandro Zummo 858a95b252SKumar Gala xfer = i2c_master_send(client, buf, 6); 868a95b252SKumar Gala if (xfer != 6) { 87edf1aaa3SAlessandro Zummo dev_err(&client->dev, "%s: send: %d\n", __FUNCTION__, xfer); 88edf1aaa3SAlessandro Zummo return -EIO; 89edf1aaa3SAlessandro Zummo } 90edf1aaa3SAlessandro Zummo 91edf1aaa3SAlessandro Zummo return 0; 92edf1aaa3SAlessandro Zummo } 93edf1aaa3SAlessandro Zummo 94edf1aaa3SAlessandro Zummo static int ds1672_set_datetime(struct i2c_client *client, struct rtc_time *tm) 95edf1aaa3SAlessandro Zummo { 96edf1aaa3SAlessandro Zummo unsigned long secs; 97edf1aaa3SAlessandro Zummo 98edf1aaa3SAlessandro Zummo dev_dbg(&client->dev, 99edf1aaa3SAlessandro Zummo "%s: secs=%d, mins=%d, hours=%d, ", 100edf1aaa3SAlessandro Zummo "mday=%d, mon=%d, year=%d, wday=%d\n", 101edf1aaa3SAlessandro Zummo __FUNCTION__, 102edf1aaa3SAlessandro Zummo tm->tm_sec, tm->tm_min, tm->tm_hour, 103edf1aaa3SAlessandro Zummo tm->tm_mday, tm->tm_mon, tm->tm_year, tm->tm_wday); 104edf1aaa3SAlessandro Zummo 105edf1aaa3SAlessandro Zummo rtc_tm_to_time(tm, &secs); 106edf1aaa3SAlessandro Zummo 107edf1aaa3SAlessandro Zummo return ds1672_set_mmss(client, secs); 108edf1aaa3SAlessandro Zummo } 109edf1aaa3SAlessandro Zummo 110edf1aaa3SAlessandro Zummo static int ds1672_rtc_read_time(struct device *dev, struct rtc_time *tm) 111edf1aaa3SAlessandro Zummo { 112edf1aaa3SAlessandro Zummo return ds1672_get_datetime(to_i2c_client(dev), tm); 113edf1aaa3SAlessandro Zummo } 114edf1aaa3SAlessandro Zummo 115edf1aaa3SAlessandro Zummo static int ds1672_rtc_set_time(struct device *dev, struct rtc_time *tm) 116edf1aaa3SAlessandro Zummo { 117edf1aaa3SAlessandro Zummo return ds1672_set_datetime(to_i2c_client(dev), tm); 118edf1aaa3SAlessandro Zummo } 119edf1aaa3SAlessandro Zummo 120edf1aaa3SAlessandro Zummo static int ds1672_rtc_set_mmss(struct device *dev, unsigned long secs) 121edf1aaa3SAlessandro Zummo { 122edf1aaa3SAlessandro Zummo return ds1672_set_mmss(to_i2c_client(dev), secs); 123edf1aaa3SAlessandro Zummo } 124edf1aaa3SAlessandro Zummo 1258a95b252SKumar Gala static int ds1672_get_control(struct i2c_client *client, u8 *status) 1268a95b252SKumar Gala { 1278a95b252SKumar Gala unsigned char addr = DS1672_REG_CONTROL; 1288a95b252SKumar Gala 1298a95b252SKumar Gala struct i2c_msg msgs[] = { 1308a95b252SKumar Gala { client->addr, 0, 1, &addr }, /* setup read ptr */ 1318a95b252SKumar Gala { client->addr, I2C_M_RD, 1, status }, /* read control */ 1328a95b252SKumar Gala }; 1338a95b252SKumar Gala 1348a95b252SKumar Gala /* read control register */ 1358a95b252SKumar Gala if ((i2c_transfer(client->adapter, &msgs[0], 2)) != 2) { 1368a95b252SKumar Gala dev_err(&client->dev, "%s: read error\n", __FUNCTION__); 1378a95b252SKumar Gala return -EIO; 1388a95b252SKumar Gala } 1398a95b252SKumar Gala 1408a95b252SKumar Gala return 0; 1418a95b252SKumar Gala } 1428a95b252SKumar Gala 1438a95b252SKumar Gala /* following are the sysfs callback functions */ 1448a95b252SKumar Gala static ssize_t show_control(struct device *dev, struct device_attribute *attr, char *buf) 1458a95b252SKumar Gala { 1468a95b252SKumar Gala struct i2c_client *client = to_i2c_client(dev); 1478a95b252SKumar Gala u8 control; 1488a95b252SKumar Gala int err; 1498a95b252SKumar Gala 1508a95b252SKumar Gala err = ds1672_get_control(client, &control); 1518a95b252SKumar Gala if (err) 1528a95b252SKumar Gala return err; 1538a95b252SKumar Gala 1543903586aSAlessandro Zummo return sprintf(buf, "%s\n", (control & DS1672_REG_CONTROL_EOSC) 1553903586aSAlessandro Zummo ? "disabled" : "enabled"); 1568a95b252SKumar Gala } 1578a95b252SKumar Gala static DEVICE_ATTR(control, S_IRUGO, show_control, NULL); 1588a95b252SKumar Gala 159*ff8371acSDavid Brownell static const struct rtc_class_ops ds1672_rtc_ops = { 160edf1aaa3SAlessandro Zummo .read_time = ds1672_rtc_read_time, 161edf1aaa3SAlessandro Zummo .set_time = ds1672_rtc_set_time, 162edf1aaa3SAlessandro Zummo .set_mmss = ds1672_rtc_set_mmss, 163edf1aaa3SAlessandro Zummo }; 164edf1aaa3SAlessandro Zummo 165edf1aaa3SAlessandro Zummo static int ds1672_attach(struct i2c_adapter *adapter) 166edf1aaa3SAlessandro Zummo { 167edf1aaa3SAlessandro Zummo return i2c_probe(adapter, &addr_data, ds1672_probe); 168edf1aaa3SAlessandro Zummo } 169edf1aaa3SAlessandro Zummo 170edf1aaa3SAlessandro Zummo static int ds1672_detach(struct i2c_client *client) 171edf1aaa3SAlessandro Zummo { 172edf1aaa3SAlessandro Zummo int err; 173edf1aaa3SAlessandro Zummo struct rtc_device *rtc = i2c_get_clientdata(client); 174edf1aaa3SAlessandro Zummo 175edf1aaa3SAlessandro Zummo if (rtc) 176edf1aaa3SAlessandro Zummo rtc_device_unregister(rtc); 177edf1aaa3SAlessandro Zummo 178edf1aaa3SAlessandro Zummo if ((err = i2c_detach_client(client))) 179edf1aaa3SAlessandro Zummo return err; 180edf1aaa3SAlessandro Zummo 181edf1aaa3SAlessandro Zummo kfree(client); 182edf1aaa3SAlessandro Zummo 183edf1aaa3SAlessandro Zummo return 0; 184edf1aaa3SAlessandro Zummo } 185edf1aaa3SAlessandro Zummo 186edf1aaa3SAlessandro Zummo static struct i2c_driver ds1672_driver = { 187edf1aaa3SAlessandro Zummo .driver = { 188edf1aaa3SAlessandro Zummo .name = "ds1672", 189edf1aaa3SAlessandro Zummo }, 190edf1aaa3SAlessandro Zummo .id = I2C_DRIVERID_DS1672, 191edf1aaa3SAlessandro Zummo .attach_adapter = &ds1672_attach, 192edf1aaa3SAlessandro Zummo .detach_client = &ds1672_detach, 193edf1aaa3SAlessandro Zummo }; 194edf1aaa3SAlessandro Zummo 195edf1aaa3SAlessandro Zummo static int ds1672_probe(struct i2c_adapter *adapter, int address, int kind) 196edf1aaa3SAlessandro Zummo { 197edf1aaa3SAlessandro Zummo int err = 0; 1988a95b252SKumar Gala u8 control; 199edf1aaa3SAlessandro Zummo struct i2c_client *client; 200edf1aaa3SAlessandro Zummo struct rtc_device *rtc; 201edf1aaa3SAlessandro Zummo 202edf1aaa3SAlessandro Zummo dev_dbg(&adapter->dev, "%s\n", __FUNCTION__); 203edf1aaa3SAlessandro Zummo 204edf1aaa3SAlessandro Zummo if (!i2c_check_functionality(adapter, I2C_FUNC_I2C)) { 205edf1aaa3SAlessandro Zummo err = -ENODEV; 206edf1aaa3SAlessandro Zummo goto exit; 207edf1aaa3SAlessandro Zummo } 208edf1aaa3SAlessandro Zummo 209edf1aaa3SAlessandro Zummo if (!(client = kzalloc(sizeof(struct i2c_client), GFP_KERNEL))) { 210edf1aaa3SAlessandro Zummo err = -ENOMEM; 211edf1aaa3SAlessandro Zummo goto exit; 212edf1aaa3SAlessandro Zummo } 213edf1aaa3SAlessandro Zummo 214edf1aaa3SAlessandro Zummo /* I2C client */ 215edf1aaa3SAlessandro Zummo client->addr = address; 216edf1aaa3SAlessandro Zummo client->driver = &ds1672_driver; 217edf1aaa3SAlessandro Zummo client->adapter = adapter; 218edf1aaa3SAlessandro Zummo 219edf1aaa3SAlessandro Zummo strlcpy(client->name, ds1672_driver.driver.name, I2C_NAME_SIZE); 220edf1aaa3SAlessandro Zummo 221edf1aaa3SAlessandro Zummo /* Inform the i2c layer */ 222edf1aaa3SAlessandro Zummo if ((err = i2c_attach_client(client))) 223edf1aaa3SAlessandro Zummo goto exit_kfree; 224edf1aaa3SAlessandro Zummo 225edf1aaa3SAlessandro Zummo dev_info(&client->dev, "chip found, driver version " DRV_VERSION "\n"); 226edf1aaa3SAlessandro Zummo 227edf1aaa3SAlessandro Zummo rtc = rtc_device_register(ds1672_driver.driver.name, &client->dev, 228edf1aaa3SAlessandro Zummo &ds1672_rtc_ops, THIS_MODULE); 229edf1aaa3SAlessandro Zummo 230edf1aaa3SAlessandro Zummo if (IS_ERR(rtc)) { 231edf1aaa3SAlessandro Zummo err = PTR_ERR(rtc); 232edf1aaa3SAlessandro Zummo goto exit_detach; 233edf1aaa3SAlessandro Zummo } 234edf1aaa3SAlessandro Zummo 235edf1aaa3SAlessandro Zummo i2c_set_clientdata(client, rtc); 236edf1aaa3SAlessandro Zummo 2378a95b252SKumar Gala /* read control register */ 2388a95b252SKumar Gala err = ds1672_get_control(client, &control); 2393903586aSAlessandro Zummo if (err) 2408a95b252SKumar Gala goto exit_detach; 2418a95b252SKumar Gala 2428a95b252SKumar Gala if (control & DS1672_REG_CONTROL_EOSC) 2438a95b252SKumar Gala dev_warn(&client->dev, "Oscillator not enabled. " 2448a95b252SKumar Gala "Set time to enable.\n"); 2458a95b252SKumar Gala 2468a95b252SKumar Gala /* Register sysfs hooks */ 2478a95b252SKumar Gala device_create_file(&client->dev, &dev_attr_control); 2488a95b252SKumar Gala 249edf1aaa3SAlessandro Zummo return 0; 250edf1aaa3SAlessandro Zummo 251edf1aaa3SAlessandro Zummo exit_detach: 252edf1aaa3SAlessandro Zummo i2c_detach_client(client); 253edf1aaa3SAlessandro Zummo 254edf1aaa3SAlessandro Zummo exit_kfree: 255edf1aaa3SAlessandro Zummo kfree(client); 256edf1aaa3SAlessandro Zummo 257edf1aaa3SAlessandro Zummo exit: 258edf1aaa3SAlessandro Zummo return err; 259edf1aaa3SAlessandro Zummo } 260edf1aaa3SAlessandro Zummo 261edf1aaa3SAlessandro Zummo static int __init ds1672_init(void) 262edf1aaa3SAlessandro Zummo { 263edf1aaa3SAlessandro Zummo return i2c_add_driver(&ds1672_driver); 264edf1aaa3SAlessandro Zummo } 265edf1aaa3SAlessandro Zummo 266edf1aaa3SAlessandro Zummo static void __exit ds1672_exit(void) 267edf1aaa3SAlessandro Zummo { 268edf1aaa3SAlessandro Zummo i2c_del_driver(&ds1672_driver); 269edf1aaa3SAlessandro Zummo } 270edf1aaa3SAlessandro Zummo 271edf1aaa3SAlessandro Zummo MODULE_AUTHOR("Alessandro Zummo <a.zummo@towertech.it>"); 272edf1aaa3SAlessandro Zummo MODULE_DESCRIPTION("Dallas/Maxim DS1672 timekeeper driver"); 273edf1aaa3SAlessandro Zummo MODULE_LICENSE("GPL"); 274edf1aaa3SAlessandro Zummo MODULE_VERSION(DRV_VERSION); 275edf1aaa3SAlessandro Zummo 276edf1aaa3SAlessandro Zummo module_init(ds1672_init); 277edf1aaa3SAlessandro Zummo module_exit(ds1672_exit); 278