1*edf1aaa3SAlessandro Zummo /* 2*edf1aaa3SAlessandro Zummo * An rtc/i2c driver for the Dallas DS1672 3*edf1aaa3SAlessandro Zummo * Copyright 2005 Alessandro Zummo 4*edf1aaa3SAlessandro Zummo * 5*edf1aaa3SAlessandro Zummo * This program is free software; you can redistribute it and/or modify 6*edf1aaa3SAlessandro Zummo * it under the terms of the GNU General Public License version 2 as 7*edf1aaa3SAlessandro Zummo * published by the Free Software Foundation. 8*edf1aaa3SAlessandro Zummo */ 9*edf1aaa3SAlessandro Zummo 10*edf1aaa3SAlessandro Zummo #include <linux/module.h> 11*edf1aaa3SAlessandro Zummo #include <linux/i2c.h> 12*edf1aaa3SAlessandro Zummo #include <linux/rtc.h> 13*edf1aaa3SAlessandro Zummo 14*edf1aaa3SAlessandro Zummo #define DRV_VERSION "0.2" 15*edf1aaa3SAlessandro Zummo 16*edf1aaa3SAlessandro Zummo /* Addresses to scan: none. This chip cannot be detected. */ 17*edf1aaa3SAlessandro Zummo static unsigned short normal_i2c[] = { I2C_CLIENT_END }; 18*edf1aaa3SAlessandro Zummo 19*edf1aaa3SAlessandro Zummo /* Insmod parameters */ 20*edf1aaa3SAlessandro Zummo I2C_CLIENT_INSMOD; 21*edf1aaa3SAlessandro Zummo 22*edf1aaa3SAlessandro Zummo /* Registers */ 23*edf1aaa3SAlessandro Zummo 24*edf1aaa3SAlessandro Zummo #define DS1672_REG_CNT_BASE 0 25*edf1aaa3SAlessandro Zummo #define DS1672_REG_CONTROL 4 26*edf1aaa3SAlessandro Zummo #define DS1672_REG_TRICKLE 5 27*edf1aaa3SAlessandro Zummo 28*edf1aaa3SAlessandro Zummo 29*edf1aaa3SAlessandro Zummo /* Prototypes */ 30*edf1aaa3SAlessandro Zummo static int ds1672_probe(struct i2c_adapter *adapter, int address, int kind); 31*edf1aaa3SAlessandro Zummo 32*edf1aaa3SAlessandro Zummo /* 33*edf1aaa3SAlessandro Zummo * In the routines that deal directly with the ds1672 hardware, we use 34*edf1aaa3SAlessandro Zummo * rtc_time -- month 0-11, hour 0-23, yr = calendar year-epoch 35*edf1aaa3SAlessandro Zummo * Epoch is initialized as 2000. Time is set to UTC. 36*edf1aaa3SAlessandro Zummo */ 37*edf1aaa3SAlessandro Zummo static int ds1672_get_datetime(struct i2c_client *client, struct rtc_time *tm) 38*edf1aaa3SAlessandro Zummo { 39*edf1aaa3SAlessandro Zummo unsigned long time; 40*edf1aaa3SAlessandro Zummo unsigned char addr = DS1672_REG_CNT_BASE; 41*edf1aaa3SAlessandro Zummo unsigned char buf[4]; 42*edf1aaa3SAlessandro Zummo 43*edf1aaa3SAlessandro Zummo struct i2c_msg msgs[] = { 44*edf1aaa3SAlessandro Zummo { client->addr, 0, 1, &addr }, /* setup read ptr */ 45*edf1aaa3SAlessandro Zummo { client->addr, I2C_M_RD, 4, buf }, /* read date */ 46*edf1aaa3SAlessandro Zummo }; 47*edf1aaa3SAlessandro Zummo 48*edf1aaa3SAlessandro Zummo /* read date registers */ 49*edf1aaa3SAlessandro Zummo if ((i2c_transfer(client->adapter, &msgs[0], 2)) != 2) { 50*edf1aaa3SAlessandro Zummo dev_err(&client->dev, "%s: read error\n", __FUNCTION__); 51*edf1aaa3SAlessandro Zummo return -EIO; 52*edf1aaa3SAlessandro Zummo } 53*edf1aaa3SAlessandro Zummo 54*edf1aaa3SAlessandro Zummo dev_dbg(&client->dev, 55*edf1aaa3SAlessandro Zummo "%s: raw read data - counters=%02x,%02x,%02x,%02x\n" 56*edf1aaa3SAlessandro Zummo __FUNCTION__, 57*edf1aaa3SAlessandro Zummo buf[0], buf[1], buf[2], buf[3]); 58*edf1aaa3SAlessandro Zummo 59*edf1aaa3SAlessandro Zummo time = (buf[3] << 24) | (buf[2] << 16) | (buf[1] << 8) | buf[0]; 60*edf1aaa3SAlessandro Zummo 61*edf1aaa3SAlessandro Zummo rtc_time_to_tm(time, tm); 62*edf1aaa3SAlessandro Zummo 63*edf1aaa3SAlessandro Zummo dev_dbg(&client->dev, "%s: tm is secs=%d, mins=%d, hours=%d, " 64*edf1aaa3SAlessandro Zummo "mday=%d, mon=%d, year=%d, wday=%d\n", 65*edf1aaa3SAlessandro Zummo __FUNCTION__, 66*edf1aaa3SAlessandro Zummo tm->tm_sec, tm->tm_min, tm->tm_hour, 67*edf1aaa3SAlessandro Zummo tm->tm_mday, tm->tm_mon, tm->tm_year, tm->tm_wday); 68*edf1aaa3SAlessandro Zummo 69*edf1aaa3SAlessandro Zummo return 0; 70*edf1aaa3SAlessandro Zummo } 71*edf1aaa3SAlessandro Zummo 72*edf1aaa3SAlessandro Zummo static int ds1672_set_mmss(struct i2c_client *client, unsigned long secs) 73*edf1aaa3SAlessandro Zummo { 74*edf1aaa3SAlessandro Zummo int xfer; 75*edf1aaa3SAlessandro Zummo unsigned char buf[5]; 76*edf1aaa3SAlessandro Zummo 77*edf1aaa3SAlessandro Zummo buf[0] = DS1672_REG_CNT_BASE; 78*edf1aaa3SAlessandro Zummo buf[1] = secs & 0x000000FF; 79*edf1aaa3SAlessandro Zummo buf[2] = (secs & 0x0000FF00) >> 8; 80*edf1aaa3SAlessandro Zummo buf[3] = (secs & 0x00FF0000) >> 16; 81*edf1aaa3SAlessandro Zummo buf[4] = (secs & 0xFF000000) >> 24; 82*edf1aaa3SAlessandro Zummo 83*edf1aaa3SAlessandro Zummo xfer = i2c_master_send(client, buf, 5); 84*edf1aaa3SAlessandro Zummo if (xfer != 5) { 85*edf1aaa3SAlessandro Zummo dev_err(&client->dev, "%s: send: %d\n", __FUNCTION__, xfer); 86*edf1aaa3SAlessandro Zummo return -EIO; 87*edf1aaa3SAlessandro Zummo } 88*edf1aaa3SAlessandro Zummo 89*edf1aaa3SAlessandro Zummo return 0; 90*edf1aaa3SAlessandro Zummo } 91*edf1aaa3SAlessandro Zummo 92*edf1aaa3SAlessandro Zummo static int ds1672_set_datetime(struct i2c_client *client, struct rtc_time *tm) 93*edf1aaa3SAlessandro Zummo { 94*edf1aaa3SAlessandro Zummo unsigned long secs; 95*edf1aaa3SAlessandro Zummo 96*edf1aaa3SAlessandro Zummo dev_dbg(&client->dev, 97*edf1aaa3SAlessandro Zummo "%s: secs=%d, mins=%d, hours=%d, ", 98*edf1aaa3SAlessandro Zummo "mday=%d, mon=%d, year=%d, wday=%d\n", 99*edf1aaa3SAlessandro Zummo __FUNCTION__, 100*edf1aaa3SAlessandro Zummo tm->tm_sec, tm->tm_min, tm->tm_hour, 101*edf1aaa3SAlessandro Zummo tm->tm_mday, tm->tm_mon, tm->tm_year, tm->tm_wday); 102*edf1aaa3SAlessandro Zummo 103*edf1aaa3SAlessandro Zummo rtc_tm_to_time(tm, &secs); 104*edf1aaa3SAlessandro Zummo 105*edf1aaa3SAlessandro Zummo return ds1672_set_mmss(client, secs); 106*edf1aaa3SAlessandro Zummo } 107*edf1aaa3SAlessandro Zummo 108*edf1aaa3SAlessandro Zummo static int ds1672_rtc_read_time(struct device *dev, struct rtc_time *tm) 109*edf1aaa3SAlessandro Zummo { 110*edf1aaa3SAlessandro Zummo return ds1672_get_datetime(to_i2c_client(dev), tm); 111*edf1aaa3SAlessandro Zummo } 112*edf1aaa3SAlessandro Zummo 113*edf1aaa3SAlessandro Zummo static int ds1672_rtc_set_time(struct device *dev, struct rtc_time *tm) 114*edf1aaa3SAlessandro Zummo { 115*edf1aaa3SAlessandro Zummo return ds1672_set_datetime(to_i2c_client(dev), tm); 116*edf1aaa3SAlessandro Zummo } 117*edf1aaa3SAlessandro Zummo 118*edf1aaa3SAlessandro Zummo static int ds1672_rtc_set_mmss(struct device *dev, unsigned long secs) 119*edf1aaa3SAlessandro Zummo { 120*edf1aaa3SAlessandro Zummo return ds1672_set_mmss(to_i2c_client(dev), secs); 121*edf1aaa3SAlessandro Zummo } 122*edf1aaa3SAlessandro Zummo 123*edf1aaa3SAlessandro Zummo static struct rtc_class_ops ds1672_rtc_ops = { 124*edf1aaa3SAlessandro Zummo .read_time = ds1672_rtc_read_time, 125*edf1aaa3SAlessandro Zummo .set_time = ds1672_rtc_set_time, 126*edf1aaa3SAlessandro Zummo .set_mmss = ds1672_rtc_set_mmss, 127*edf1aaa3SAlessandro Zummo }; 128*edf1aaa3SAlessandro Zummo 129*edf1aaa3SAlessandro Zummo static int ds1672_attach(struct i2c_adapter *adapter) 130*edf1aaa3SAlessandro Zummo { 131*edf1aaa3SAlessandro Zummo dev_dbg(&adapter->dev, "%s\n", __FUNCTION__); 132*edf1aaa3SAlessandro Zummo return i2c_probe(adapter, &addr_data, ds1672_probe); 133*edf1aaa3SAlessandro Zummo } 134*edf1aaa3SAlessandro Zummo 135*edf1aaa3SAlessandro Zummo static int ds1672_detach(struct i2c_client *client) 136*edf1aaa3SAlessandro Zummo { 137*edf1aaa3SAlessandro Zummo int err; 138*edf1aaa3SAlessandro Zummo struct rtc_device *rtc = i2c_get_clientdata(client); 139*edf1aaa3SAlessandro Zummo 140*edf1aaa3SAlessandro Zummo dev_dbg(&client->dev, "%s\n", __FUNCTION__); 141*edf1aaa3SAlessandro Zummo 142*edf1aaa3SAlessandro Zummo if (rtc) 143*edf1aaa3SAlessandro Zummo rtc_device_unregister(rtc); 144*edf1aaa3SAlessandro Zummo 145*edf1aaa3SAlessandro Zummo if ((err = i2c_detach_client(client))) 146*edf1aaa3SAlessandro Zummo return err; 147*edf1aaa3SAlessandro Zummo 148*edf1aaa3SAlessandro Zummo kfree(client); 149*edf1aaa3SAlessandro Zummo 150*edf1aaa3SAlessandro Zummo return 0; 151*edf1aaa3SAlessandro Zummo } 152*edf1aaa3SAlessandro Zummo 153*edf1aaa3SAlessandro Zummo static struct i2c_driver ds1672_driver = { 154*edf1aaa3SAlessandro Zummo .driver = { 155*edf1aaa3SAlessandro Zummo .name = "ds1672", 156*edf1aaa3SAlessandro Zummo }, 157*edf1aaa3SAlessandro Zummo .id = I2C_DRIVERID_DS1672, 158*edf1aaa3SAlessandro Zummo .attach_adapter = &ds1672_attach, 159*edf1aaa3SAlessandro Zummo .detach_client = &ds1672_detach, 160*edf1aaa3SAlessandro Zummo }; 161*edf1aaa3SAlessandro Zummo 162*edf1aaa3SAlessandro Zummo static int ds1672_probe(struct i2c_adapter *adapter, int address, int kind) 163*edf1aaa3SAlessandro Zummo { 164*edf1aaa3SAlessandro Zummo int err = 0; 165*edf1aaa3SAlessandro Zummo struct i2c_client *client; 166*edf1aaa3SAlessandro Zummo struct rtc_device *rtc; 167*edf1aaa3SAlessandro Zummo 168*edf1aaa3SAlessandro Zummo dev_dbg(&adapter->dev, "%s\n", __FUNCTION__); 169*edf1aaa3SAlessandro Zummo 170*edf1aaa3SAlessandro Zummo if (!i2c_check_functionality(adapter, I2C_FUNC_I2C)) { 171*edf1aaa3SAlessandro Zummo err = -ENODEV; 172*edf1aaa3SAlessandro Zummo goto exit; 173*edf1aaa3SAlessandro Zummo } 174*edf1aaa3SAlessandro Zummo 175*edf1aaa3SAlessandro Zummo if (!(client = kzalloc(sizeof(struct i2c_client), GFP_KERNEL))) { 176*edf1aaa3SAlessandro Zummo err = -ENOMEM; 177*edf1aaa3SAlessandro Zummo goto exit; 178*edf1aaa3SAlessandro Zummo } 179*edf1aaa3SAlessandro Zummo 180*edf1aaa3SAlessandro Zummo /* I2C client */ 181*edf1aaa3SAlessandro Zummo client->addr = address; 182*edf1aaa3SAlessandro Zummo client->driver = &ds1672_driver; 183*edf1aaa3SAlessandro Zummo client->adapter = adapter; 184*edf1aaa3SAlessandro Zummo 185*edf1aaa3SAlessandro Zummo strlcpy(client->name, ds1672_driver.driver.name, I2C_NAME_SIZE); 186*edf1aaa3SAlessandro Zummo 187*edf1aaa3SAlessandro Zummo /* Inform the i2c layer */ 188*edf1aaa3SAlessandro Zummo if ((err = i2c_attach_client(client))) 189*edf1aaa3SAlessandro Zummo goto exit_kfree; 190*edf1aaa3SAlessandro Zummo 191*edf1aaa3SAlessandro Zummo dev_info(&client->dev, "chip found, driver version " DRV_VERSION "\n"); 192*edf1aaa3SAlessandro Zummo 193*edf1aaa3SAlessandro Zummo rtc = rtc_device_register(ds1672_driver.driver.name, &client->dev, 194*edf1aaa3SAlessandro Zummo &ds1672_rtc_ops, THIS_MODULE); 195*edf1aaa3SAlessandro Zummo 196*edf1aaa3SAlessandro Zummo if (IS_ERR(rtc)) { 197*edf1aaa3SAlessandro Zummo err = PTR_ERR(rtc); 198*edf1aaa3SAlessandro Zummo dev_err(&client->dev, 199*edf1aaa3SAlessandro Zummo "unable to register the class device\n"); 200*edf1aaa3SAlessandro Zummo goto exit_detach; 201*edf1aaa3SAlessandro Zummo } 202*edf1aaa3SAlessandro Zummo 203*edf1aaa3SAlessandro Zummo i2c_set_clientdata(client, rtc); 204*edf1aaa3SAlessandro Zummo 205*edf1aaa3SAlessandro Zummo return 0; 206*edf1aaa3SAlessandro Zummo 207*edf1aaa3SAlessandro Zummo exit_detach: 208*edf1aaa3SAlessandro Zummo i2c_detach_client(client); 209*edf1aaa3SAlessandro Zummo 210*edf1aaa3SAlessandro Zummo exit_kfree: 211*edf1aaa3SAlessandro Zummo kfree(client); 212*edf1aaa3SAlessandro Zummo 213*edf1aaa3SAlessandro Zummo exit: 214*edf1aaa3SAlessandro Zummo return err; 215*edf1aaa3SAlessandro Zummo } 216*edf1aaa3SAlessandro Zummo 217*edf1aaa3SAlessandro Zummo static int __init ds1672_init(void) 218*edf1aaa3SAlessandro Zummo { 219*edf1aaa3SAlessandro Zummo return i2c_add_driver(&ds1672_driver); 220*edf1aaa3SAlessandro Zummo } 221*edf1aaa3SAlessandro Zummo 222*edf1aaa3SAlessandro Zummo static void __exit ds1672_exit(void) 223*edf1aaa3SAlessandro Zummo { 224*edf1aaa3SAlessandro Zummo i2c_del_driver(&ds1672_driver); 225*edf1aaa3SAlessandro Zummo } 226*edf1aaa3SAlessandro Zummo 227*edf1aaa3SAlessandro Zummo MODULE_AUTHOR("Alessandro Zummo <a.zummo@towertech.it>"); 228*edf1aaa3SAlessandro Zummo MODULE_DESCRIPTION("Dallas/Maxim DS1672 timekeeper driver"); 229*edf1aaa3SAlessandro Zummo MODULE_LICENSE("GPL"); 230*edf1aaa3SAlessandro Zummo MODULE_VERSION(DRV_VERSION); 231*edf1aaa3SAlessandro Zummo 232*edf1aaa3SAlessandro Zummo module_init(ds1672_init); 233*edf1aaa3SAlessandro Zummo module_exit(ds1672_exit); 234