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Commit 7520b94d authored by Alessandro Zummo's avatar Alessandro Zummo Committed by Linus Torvalds
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[PATCH] RTC subsystem: RS5C372 driver 



RTC class aware driver for the Ricoh RS5C372 chip used, among others, on the
Synology DS101.

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 b5a82d62

drivers/rtc/Kconfig

+10 −0
Original line number Diff line number Diff line
@@ -107,6 +107,16 @@ config RTC_DRV_PCF8563 
	  This driver can also be built as a module. If so, the module

	  will be called rtc-pcf8563.



config RTC_DRV_RS5C372

	tristate "Ricoh RS5C372A/B"

	depends on RTC_CLASS && I2C

	help

	  If you say yes here you get support for the

	  Ricoh RS5C372A and RS5C372B RTC chips.



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

	  will be called rtc-rs5c372.



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
@@ -15,4 +15,5 @@ obj-$(CONFIG_RTC_DRV_X1205) += rtc-x1205.o 
obj-$(CONFIG_RTC_DRV_TEST)	+= rtc-test.o

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

obj-$(CONFIG_RTC_DRV_PCF8563)	+= rtc-pcf8563.o

obj-$(CONFIG_RTC_DRV_RS5C372)	+= rtc-rs5c372.o

drivers/rtc/rtc-rs5c372.c

0 → 100644
+294 −0
Original line number Diff line number Diff line 
/*

 * An I2C driver for the Ricoh RS5C372 RTC

 *

 * Copyright (C) 2005 Pavel Mironchik <pmironchik@optifacio.net>

 * Copyright (C) 2006 Tower Technologies

 *

 * 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/i2c.h>

#include <linux/rtc.h>

#include <linux/bcd.h>



#define DRV_VERSION "0.2"



/* Addresses to scan */

static unsigned short normal_i2c[] = { /* 0x32,*/ I2C_CLIENT_END };



/* Insmod parameters */

I2C_CLIENT_INSMOD;



#define RS5C372_REG_SECS	0

#define RS5C372_REG_MINS	1

#define RS5C372_REG_HOURS	2

#define RS5C372_REG_WDAY	3

#define RS5C372_REG_DAY		4

#define RS5C372_REG_MONTH	5

#define RS5C372_REG_YEAR	6

#define RS5C372_REG_TRIM	7



#define RS5C372_TRIM_XSL	0x80

#define RS5C372_TRIM_MASK	0x7F



#define RS5C372_REG_BASE	0



static int rs5c372_attach(struct i2c_adapter *adapter);

static int rs5c372_detach(struct i2c_client *client);

static int rs5c372_probe(struct i2c_adapter *adapter, int address, int kind);



static struct i2c_driver rs5c372_driver = {

	.driver		= {

		.name	= "rs5c372",

	},

	.attach_adapter	= &rs5c372_attach,

	.detach_client	= &rs5c372_detach,

};



static int rs5c372_get_datetime(struct i2c_client *client, struct rtc_time *tm)

{

	unsigned char buf[7] = { RS5C372_REG_BASE };



	/* this implements the 1st reading method, according

	 * to the datasheet. buf[0] is initialized with

	 * address ptr and transmission format register.

	 */

	struct i2c_msg msgs[] = {

		{ client->addr, 0, 1, buf },

		{ client->addr, I2C_M_RD, 7, buf },

	};



	if ((i2c_transfer(client->adapter, msgs, 2)) != 2) {

		dev_err(&client->dev, "%s: read error\n", __FUNCTION__);

		return -EIO;

	}



	tm->tm_sec = BCD2BIN(buf[RS5C372_REG_SECS] & 0x7f);

	tm->tm_min = BCD2BIN(buf[RS5C372_REG_MINS] & 0x7f);

	tm->tm_hour = BCD2BIN(buf[RS5C372_REG_HOURS] & 0x3f);

	tm->tm_wday = BCD2BIN(buf[RS5C372_REG_WDAY] & 0x07);

	tm->tm_mday = BCD2BIN(buf[RS5C372_REG_DAY] & 0x3f);



	/* tm->tm_mon is zero-based */

	tm->tm_mon = BCD2BIN(buf[RS5C372_REG_MONTH] & 0x1f) - 1;



	/* year is 1900 + tm->tm_year */

	tm->tm_year = BCD2BIN(buf[RS5C372_REG_YEAR]) + 100;



	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 rs5c372_set_datetime(struct i2c_client *client, struct rtc_time *tm)

{

	unsigned char buf[8] = { RS5C372_REG_BASE };



	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);



	buf[1] = BIN2BCD(tm->tm_sec);

	buf[2] = BIN2BCD(tm->tm_min);

	buf[3] = BIN2BCD(tm->tm_hour);

	buf[4] = BIN2BCD(tm->tm_wday);

	buf[5] = BIN2BCD(tm->tm_mday);

	buf[6] = BIN2BCD(tm->tm_mon + 1);

	buf[7] = BIN2BCD(tm->tm_year - 100);



	if ((i2c_master_send(client, buf, 8)) != 8) {

		dev_err(&client->dev, "%s: write error\n", __FUNCTION__);

		return -EIO;

	}



	return 0;

}



static int rs5c372_get_trim(struct i2c_client *client, int *osc, int *trim)

{

	unsigned char buf = RS5C372_REG_TRIM;



	struct i2c_msg msgs[] = {

		{ client->addr, 0, 1, &buf },

		{ client->addr, I2C_M_RD, 1, &buf },

	};



	if ((i2c_transfer(client->adapter, msgs, 2)) != 2) {

		dev_err(&client->dev, "%s: read error\n", __FUNCTION__);

		return -EIO;

	}



	dev_dbg(&client->dev, "%s: raw trim=%x\n", __FUNCTION__, trim);



	if (osc)

		*osc = (buf & RS5C372_TRIM_XSL) ? 32000 : 32768;



	if (trim)

		*trim = buf & RS5C372_TRIM_MASK;



	return 0;

}



static int rs5c372_rtc_read_time(struct device *dev, struct rtc_time *tm)

{

	return rs5c372_get_datetime(to_i2c_client(dev), tm);

}



static int rs5c372_rtc_set_time(struct device *dev, struct rtc_time *tm)

{

	return rs5c372_set_datetime(to_i2c_client(dev), tm);

}



static int rs5c372_rtc_proc(struct device *dev, struct seq_file *seq)

{

	int err, osc, trim;



	seq_printf(seq, "24hr\t\t: yes\n");



	if ((err = rs5c372_get_trim(to_i2c_client(dev), &osc, &trim)) == 0) {

		seq_printf(seq, "%d.%03d KHz\n", osc / 1000, osc % 1000);

		seq_printf(seq, "trim\t: %d\n", trim);

	}



	return 0;

}



static struct rtc_class_ops rs5c372_rtc_ops = {

	.proc		= rs5c372_rtc_proc,

	.read_time	= rs5c372_rtc_read_time,

	.set_time	= rs5c372_rtc_set_time,

};



static ssize_t rs5c372_sysfs_show_trim(struct device *dev,

				struct device_attribute *attr, char *buf)

{

	int trim;



	if (rs5c372_get_trim(to_i2c_client(dev), NULL, &trim) == 0)

		return sprintf(buf, "0x%2x\n", trim);



	return 0;

}

static DEVICE_ATTR(trim, S_IRUGO, rs5c372_sysfs_show_trim, NULL);



static ssize_t rs5c372_sysfs_show_osc(struct device *dev,

				struct device_attribute *attr, char *buf)

{

	int osc;



	if (rs5c372_get_trim(to_i2c_client(dev), &osc, NULL) == 0)

		return sprintf(buf, "%d.%03d KHz\n", osc / 1000, osc % 1000);



	return 0;

}

static DEVICE_ATTR(osc, S_IRUGO, rs5c372_sysfs_show_osc, NULL);



static int rs5c372_attach(struct i2c_adapter *adapter)

{

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

	return i2c_probe(adapter, &addr_data, rs5c372_probe);

}



static int rs5c372_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 = &rs5c372_driver;

	client->adapter = adapter;



	strlcpy(client->name, rs5c372_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(rs5c372_driver.driver.name, &client->dev,

				&rs5c372_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);



	device_create_file(&client->dev, &dev_attr_trim);

	device_create_file(&client->dev, &dev_attr_osc);



	return 0;



exit_detach:

	i2c_detach_client(client);



exit_kfree:

	kfree(client);



exit:

	return err;

}



static int rs5c372_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 __init int rs5c372_init(void)

{

	return i2c_add_driver(&rs5c372_driver);

}



static __exit void rs5c372_exit(void)

{

	i2c_del_driver(&rs5c372_driver);

}



module_init(rs5c372_init);

module_exit(rs5c372_exit);



MODULE_AUTHOR(

		"Pavel Mironchik <pmironchik@optifacio.net>, "

		"Alessandro Zummo <a.zummo@towertech.it>");

MODULE_DESCRIPTION("Ricoh RS5C372 RTC driver");

MODULE_LICENSE("GPL");

MODULE_VERSION(DRV_VERSION);