Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit edf1aaa3 authored by Alessandro Zummo's avatar Alessandro Zummo Committed by Linus Torvalds
Browse files

[PATCH] RTC subsystem: DS1672 driver 

Driver for the Dallas/Maxim DS1672 chip, found on the Loft
(http://www.giantshoulderinc.com

).

Signed-off-by: default avatarAlessandro Zummo <a.zummo@towertech.it>
Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
parent a95579cd

drivers/rtc/Kconfig

+10 −0
Original line number Diff line number Diff line
@@ -86,6 +86,16 @@ config RTC_DRV_X1205 
	  This driver can also be built as a module. If so, the module

	  will be called rtc-x1205.



config RTC_DRV_DS1672

	tristate "Dallas/Maxim DS1672"

	depends on RTC_CLASS && I2C

	help

	  If you say yes here you get support for the

	  Dallas/Maxim DS1672 timekeeping chip.



	  This driver can also be built as a module. If so, the module

	  will be called rtc-ds1672.



config RTC_DRV_TEST

	tristate "Test driver/device"

	depends on RTC_CLASS

drivers/rtc/Makefile

+1 −0
Original line number Diff line number Diff line
@@ -13,4 +13,5 @@ obj-$(CONFIG_RTC_INTF_DEV) += rtc-dev.o 


obj-$(CONFIG_RTC_DRV_X1205)	+= rtc-x1205.o

obj-$(CONFIG_RTC_DRV_TEST)	+= rtc-test.o

obj-$(CONFIG_RTC_DRV_DS1672)	+= rtc-ds1672.o

drivers/rtc/rtc-ds1672.c

0 → 100644
+233 −0
Original line number Diff line number Diff line 
/*

 * An rtc/i2c driver for the Dallas DS1672

 * Copyright 2005 Alessandro Zummo

 *

 * 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 "0.2"



/* 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





/* 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[5];



	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;



	xfer = i2c_master_send(client, buf, 5);

	if (xfer != 5) {

		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 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)

{

	dev_dbg(&adapter->dev, "%s\n", __FUNCTION__);

	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);



	dev_dbg(&client->dev, "%s\n", __FUNCTION__);



 	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;

	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);

		dev_err(&client->dev,

			"unable to register the class device\n");

		goto exit_detach;

	}



	i2c_set_clientdata(client, rtc);



	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);