/* * An rtc/i2c driver for the Dallas DS1672 * Copyright 2005-06 Tower Technologies * * Author: Alessandro Zummo <a.zummo@towertech.it> * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License version 2 as * published by the Free Software Foundation. */ #include <linux/module.h> #include <linux/i2c.h> #include <linux/rtc.h> #define DRV_VERSION "0.3" /* Addresses to scan: none. This chip cannot be detected. */ static unsigned short normal_i2c[] = { I2C_CLIENT_END }; /* Insmod parameters */ I2C_CLIENT_INSMOD; /* Registers */ #define DS1672_REG_CNT_BASE 0 #define DS1672_REG_CONTROL 4 #define DS1672_REG_TRICKLE 5 #define DS1672_REG_CONTROL_EOSC 0x80 /* Prototypes */ static int ds1672_probe(struct i2c_adapter *adapter, int address, int kind); /* * In the routines that deal directly with the ds1672 hardware, we use * rtc_time -- month 0-11, hour 0-23, yr = calendar year-epoch * Epoch is initialized as 2000. Time is set to UTC. */ static int ds1672_get_datetime(struct i2c_client *client, struct rtc_time *tm) { unsigned long time; unsigned char addr = DS1672_REG_CNT_BASE; unsigned char buf[4]; struct i2c_msg msgs[] = { { client->addr, 0, 1, &addr }, /* setup read ptr */ { client->addr, I2C_M_RD, 4, buf }, /* read date */ }; /* read date registers */ if ((i2c_transfer(client->adapter, &msgs[0], 2)) != 2) { dev_err(&client->dev, "%s: read error\n", __FUNCTION__); return -EIO; } dev_dbg(&client->dev, "%s: raw read data - counters=%02x,%02x,%02x,%02x\n" __FUNCTION__, buf[0], buf[1], buf[2], buf[3]); time = (buf[3] << 24) | (buf[2] << 16) | (buf[1] << 8) | buf[0]; rtc_time_to_tm(time, tm); dev_dbg(&client->dev, "%s: tm is secs=%d, mins=%d, hours=%d, " "mday=%d, mon=%d, year=%d, wday=%d\n", __FUNCTION__, tm->tm_sec, tm->tm_min, tm->tm_hour, tm->tm_mday, tm->tm_mon, tm->tm_year, tm->tm_wday); return 0; } static int ds1672_set_mmss(struct i2c_client *client, unsigned long secs) { int xfer; unsigned char buf[6]; buf[0] = DS1672_REG_CNT_BASE; buf[1] = secs & 0x000000FF; buf[2] = (secs & 0x0000FF00) >> 8; buf[3] = (secs & 0x00FF0000) >> 16; buf[4] = (secs & 0xFF000000) >> 24; buf[5] = 0; /* set control reg to enable counting */ xfer = i2c_master_send(client, buf, 6); if (xfer != 6) { dev_err(&client->dev, "%s: send: %d\n", __FUNCTION__, xfer); return -EIO; } return 0; } static int ds1672_set_datetime(struct i2c_client *client, struct rtc_time *tm) { unsigned long secs; dev_dbg(&client->dev, "%s: secs=%d, mins=%d, hours=%d, ", "mday=%d, mon=%d, year=%d, wday=%d\n", __FUNCTION__, tm->tm_sec, tm->tm_min, tm->tm_hour, tm->tm_mday, tm->tm_mon, tm->tm_year, tm->tm_wday); rtc_tm_to_time(tm, &secs); return ds1672_set_mmss(client, secs); } static int ds1672_rtc_read_time(struct device *dev, struct rtc_time *tm) { return ds1672_get_datetime(to_i2c_client(dev), tm); } static int ds1672_rtc_set_time(struct device *dev, struct rtc_time *tm) { return ds1672_set_datetime(to_i2c_client(dev), tm); } static int ds1672_rtc_set_mmss(struct device *dev, unsigned long secs) { return ds1672_set_mmss(to_i2c_client(dev), secs); } static int ds1672_get_control(struct i2c_client *client, u8 *status) { unsigned char addr = DS1672_REG_CONTROL; struct i2c_msg msgs[] = { { client->addr, 0, 1, &addr }, /* setup read ptr */ { client->addr, I2C_M_RD, 1, status }, /* read control */ }; /* read control register */ if ((i2c_transfer(client->adapter, &msgs[0], 2)) != 2) { dev_err(&client->dev, "%s: read error\n", __FUNCTION__); return -EIO; } return 0; } /* following are the sysfs callback functions */ static ssize_t show_control(struct device *dev, struct device_attribute *attr, char *buf) { struct i2c_client *client = to_i2c_client(dev); u8 control; int err; err = ds1672_get_control(client, &control); if (err) return err; return sprintf(buf, "%s\n", (control & DS1672_REG_CONTROL_EOSC) ? "disabled" : "enabled"); } static DEVICE_ATTR(control, S_IRUGO, show_control, NULL); static struct rtc_class_ops ds1672_rtc_ops = { .read_time = ds1672_rtc_read_time, .set_time = ds1672_rtc_set_time, .set_mmss = ds1672_rtc_set_mmss, }; static int ds1672_attach(struct i2c_adapter *adapter) { return i2c_probe(adapter, &addr_data, ds1672_probe); } static int ds1672_detach(struct i2c_client *client) { int err; struct rtc_device *rtc = i2c_get_clientdata(client); if (rtc) rtc_device_unregister(rtc); if ((err = i2c_detach_client(client))) return err; kfree(client); return 0; } static struct i2c_driver ds1672_driver = { .driver = { .name = "ds1672", }, .id = I2C_DRIVERID_DS1672, .attach_adapter = &ds1672_attach, .detach_client = &ds1672_detach, }; static int ds1672_probe(struct i2c_adapter *adapter, int address, int kind) { int err = 0; u8 control; struct i2c_client *client; struct rtc_device *rtc; dev_dbg(&adapter->dev, "%s\n", __FUNCTION__); if (!i2c_check_functionality(adapter, I2C_FUNC_I2C)) { err = -ENODEV; goto exit; } if (!(client = kzalloc(sizeof(struct i2c_client), GFP_KERNEL))) { err = -ENOMEM; goto exit; } /* I2C client */ client->addr = address; client->driver = &ds1672_driver; client->adapter = adapter; strlcpy(client->name, ds1672_driver.driver.name, I2C_NAME_SIZE); /* Inform the i2c layer */ if ((err = i2c_attach_client(client))) goto exit_kfree; dev_info(&client->dev, "chip found, driver version " DRV_VERSION "\n"); rtc = rtc_device_register(ds1672_driver.driver.name, &client->dev, &ds1672_rtc_ops, THIS_MODULE); if (IS_ERR(rtc)) { err = PTR_ERR(rtc); goto exit_detach; } i2c_set_clientdata(client, rtc); /* read control register */ err = ds1672_get_control(client, &control); if (err) goto exit_detach; if (control & DS1672_REG_CONTROL_EOSC) dev_warn(&client->dev, "Oscillator not enabled. " "Set time to enable.\n"); /* Register sysfs hooks */ device_create_file(&client->dev, &dev_attr_control); return 0; exit_detach: i2c_detach_client(client); exit_kfree: kfree(client); exit: return err; } static int __init ds1672_init(void) { return i2c_add_driver(&ds1672_driver); } static void __exit ds1672_exit(void) { i2c_del_driver(&ds1672_driver); } MODULE_AUTHOR("Alessandro Zummo <a.zummo@towertech.it>"); MODULE_DESCRIPTION("Dallas/Maxim DS1672 timekeeper driver"); MODULE_LICENSE("GPL"); MODULE_VERSION(DRV_VERSION); module_init(ds1672_init); module_exit(ds1672_exit);