forked from mirrors/linux
		
	[PATCH] RTC subsystem: DS1672 driver
Driver for the Dallas/Maxim DS1672 chip, found on the Loft (http://www.giantshoulderinc.com). Signed-off-by: Alessandro Zummo <a.zummo@towertech.it> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
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		|  | @ -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 | ||||
|  |  | |||
|  | @ -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 | ||||
| 
 | ||||
|  |  | |||
							
								
								
									
										233
									
								
								drivers/rtc/rtc-ds1672.c
									
									
									
									
									
										Normal file
									
								
							
							
						
						
									
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								drivers/rtc/rtc-ds1672.c
									
									
									
									
									
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							|  | @ -0,0 +1,233 @@ | |||
| /*
 | ||||
|  * 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); | ||||
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	 Alessandro Zummo
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