--- /dev/null
+/*
+ * 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);
git://git.onelab.eu / linux-2.6.git / blobdiff