/* *  x1205.c - An i2c driver for the Xicor X1205 RTC *  Copyright 2004 Karen Spearel *  Copyright 2005 Alessandro Zummo * *  please send all reports to: *	kas11 at tampabay dot rr dot com *      a dot zummo at towertech dot it * *  based on the other drivers in this same directory. * *  This program is free software; you can redistribute it and/or modify *  it under the terms of the GNU General Public License as published by *  the Free Software Foundation; either version 2 of the License, or *  (at your option) any later version. */#include <linux/module.h>#include <linux/init.h>#include <linux/slab.h>#include <linux/i2c.h>#include <linux/string.h>#include <linux/bcd.h>#include <linux/rtc.h>#include <linux/list.h>#include <linux/x1205.h>#define DRV_VERSION "0.9.9"/* Addresses to scan: none. This chip is located at * 0x6f and uses a two bytes register addressing. * Two bytes need to be written to read a single register, * while most other chips just require one and take the second * one as the data to be written. To prevent corrupting * unknown chips, the user must explicitely set the probe parameter. */static unsigned short normal_i2c[] = { I2C_CLIENT_END };/* Insmod parameters */I2C_CLIENT_INSMOD;I2C_CLIENT_MODULE_PARM(hctosys,	"Set the system time from the hardware clock upon initialization");/* offsets into CCR area */#define CCR_SEC			0#define CCR_MIN			1#define CCR_HOUR		2#define CCR_MDAY		3#define CCR_MONTH		4#define CCR_YEAR		5#define CCR_WDAY		6#define CCR_Y2K			7#define X1205_REG_SR		0x3F	/* status register */#define X1205_REG_Y2K		0x37#define X1205_REG_DW		0x36#define X1205_REG_YR		0x35#define X1205_REG_MO		0x34#define X1205_REG_DT		0x33#define X1205_REG_HR		0x32#define X1205_REG_MN		0x31#define X1205_REG_SC		0x30#define X1205_REG_DTR		0x13#define X1205_REG_ATR		0x12#define X1205_REG_INT		0x11#define X1205_REG_0		0x10#define X1205_REG_Y2K1		0x0F#define X1205_REG_DWA1		0x0E#define X1205_REG_YRA1		0x0D#define X1205_REG_MOA1		0x0C#define X1205_REG_DTA1		0x0B#define X1205_REG_HRA1		0x0A#define X1205_REG_MNA1		0x09#define X1205_REG_SCA1		0x08#define X1205_REG_Y2K0		0x07#define X1205_REG_DWA0		0x06#define X1205_REG_YRA0		0x05#define X1205_REG_MOA0		0x04#define X1205_REG_DTA0		0x03#define X1205_REG_HRA0		0x02#define X1205_REG_MNA0		0x01#define X1205_REG_SCA0		0x00#define X1205_CCR_BASE		0x30	/* Base address of CCR */#define X1205_ALM0_BASE		0x00	/* Base address of ALARM0 */#define X1205_SR_RTCF		0x01	/* Clock failure */#define X1205_SR_WEL		0x02	/* Write Enable Latch */#define X1205_SR_RWEL		0x04	/* Register Write Enable */#define X1205_DTR_DTR0		0x01#define X1205_DTR_DTR1		0x02#define X1205_DTR_DTR2		0x04#define X1205_HR_MIL		0x80	/* Set in ccr.hour for 24 hr mode *//* Prototypes */static int x1205_attach(struct i2c_adapter *adapter);static int x1205_detach(struct i2c_client *client);static int x1205_probe(struct i2c_adapter *adapter, int address, int kind);static int x1205_command(struct i2c_client *client, unsigned int cmd,	void *arg);static struct i2c_driver x1205_driver = {	.driver = {		.name	= "x1205",	},	.attach_adapter = &x1205_attach,	.detach_client	= &x1205_detach,};struct x1205_data {	struct i2c_client client;	struct list_head list;	unsigned int epoch;};static const unsigned char days_in_mo[] =	{ 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31 };static LIST_HEAD(x1205_clients);/* Workaround until the I2C subsytem will allow to send * commands to a specific client. This function will send the command * to the first client. */int x1205_do_command(unsigned int cmd, void *arg){	struct list_head *walk;	struct list_head *tmp;	struct x1205_data *data;	list_for_each_safe(walk, tmp, &x1205_clients) {		data = list_entry(walk, struct x1205_data, list);		return x1205_command(&data->client, cmd, arg);	}	return -ENODEV;}#define is_leap(year) \	((year) % 4 == 0 && ((year) % 100 != 0 || (year) % 400 == 0))/* make sure the rtc_time values are in bounds */static int x1205_validate_tm(struct rtc_time *tm){	int year = tm->tm_year + 1900;	if ((tm->tm_year < 70) || (tm->tm_year > 255))		return -EINVAL;	if ((tm->tm_mon > 11) || (tm->tm_mday == 0))		return -EINVAL;	if (tm->tm_mday > days_in_mo[tm->tm_mon]		+ ((tm->tm_mon == 1) && is_leap(year)))		return -EINVAL;	if ((tm->tm_hour >= 24) || (tm->tm_min >= 60) || (tm->tm_sec >= 60))		return -EINVAL;	return 0;}/* * In the routines that deal directly with the x1205 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 x1205_get_datetime(struct i2c_client *client, struct rtc_time *tm,				u8 reg_base){	unsigned char dt_addr[2] = { 0, reg_base };	static unsigned char sr_addr[2] = { 0, X1205_REG_SR };	unsigned char buf[8], sr;	struct i2c_msg msgs[] = {		{ client->addr, 0, 2, sr_addr },	/* setup read ptr */		{ client->addr, I2C_M_RD, 1, &sr }, 	/* read status */		{ client->addr, 0, 2, dt_addr },	/* setup read ptr */		{ client->addr, I2C_M_RD, 8, buf },	/* read date */	};	struct x1205_data *data = i2c_get_clientdata(client);	/* read status register */	if ((i2c_transfer(client->adapter, &msgs[0], 2)) != 2) {		dev_err(&client->dev, "%s: read error\n", __FUNCTION__);		return -EIO;	}	/* check for battery failure */	if (sr & X1205_SR_RTCF) {		dev_warn(&client->dev,			"Clock had a power failure, you must set the date.\n");		return -EINVAL;	}	/* read date registers */	if ((i2c_transfer(client->adapter, &msgs[2], 2)) != 2) {		dev_err(&client->dev, "%s: read error\n", __FUNCTION__);		return -EIO;	}	dev_dbg(&client->dev,		"%s: raw read data - sec=%02x, min=%02x, hr=%02x, "		"mday=%02x, mon=%02x, year=%02x, wday=%02x, y2k=%02x\n",		__FUNCTION__,		buf[0], buf[1], buf[2], buf[3],		buf[4], buf[5], buf[6], buf[7]);	tm->tm_sec = BCD2BIN(buf[CCR_SEC]);	tm->tm_min = BCD2BIN(buf[CCR_MIN]);	tm->tm_hour = BCD2BIN(buf[CCR_HOUR] & 0x3F); /* hr is 0-23 */	tm->tm_mday = BCD2BIN(buf[CCR_MDAY]);	tm->tm_mon = BCD2BIN(buf[CCR_MONTH]);	data->epoch = BCD2BIN(buf[CCR_Y2K]) * 100;	tm->tm_year = BCD2BIN(buf[CCR_YEAR]) + data->epoch - 1900;	tm->tm_wday = buf[CCR_WDAY];	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 x1205_set_datetime(struct i2c_client *client, struct rtc_time *tm,				int datetoo, u8 reg_base){	int i, err, xfer;	unsigned char buf[8];	static const unsigned char wel[3] = { 0, X1205_REG_SR,						X1205_SR_WEL };	static const unsigned char rwel[3] = { 0, X1205_REG_SR,						X1205_SR_WEL | X1205_SR_RWEL };	static const unsigned char diswe[3] = { 0, X1205_REG_SR, 0 };	struct x1205_data *data = i2c_get_clientdata(client);	/* check if all values in the tm struct are correct */	if ((err = x1205_validate_tm(tm)) < 0)		return err;	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[CCR_SEC] = BIN2BCD(tm->tm_sec);	buf[CCR_MIN] = BIN2BCD(tm->tm_min);	/* set hour and 24hr bit */	buf[CCR_HOUR] = BIN2BCD(tm->tm_hour) | X1205_HR_MIL;	/* should we also set the date? */	if (datetoo) {		buf[CCR_MDAY] = BIN2BCD(tm->tm_mday);		/* month, 0 - 11 */		buf[CCR_MONTH] = BIN2BCD(tm->tm_mon);		/* year, since 1900 */		buf[CCR_YEAR] = BIN2BCD(tm->tm_year + 1900 - data->epoch);		buf[CCR_WDAY] = tm->tm_wday & 0x07;		buf[CCR_Y2K] = BIN2BCD(data->epoch / 100);	}	/* this sequence is required to unlock the chip */	xfer = i2c_master_send(client, wel, 3);	if (xfer != 3) {		dev_err(&client->dev, "%s: wel - %d\n", __FUNCTION__, xfer);		return -EIO;	}	xfer = i2c_master_send(client, rwel, 3);	if (xfer != 3) {		dev_err(&client->dev, "%s: rwel - %d\n", __FUNCTION__, xfer);		return -EIO;	}	/* write register's data */	for (i = 0; i < (datetoo ? 8 : 3); i++) {		unsigned char rdata[3] = { 0, reg_base + i, buf[i] };		xfer = i2c_master_send(client, rdata, 3);		if (xfer != 3) {			dev_err(&client->dev,				"%s: xfer=%d addr=%02x, data=%02x\n",				__FUNCTION__,				 xfer, rdata[1], rdata[2]);			return -EIO;		}	};	/* disable further writes */	xfer = i2c_master_send(client, diswe, 3);	if (xfer != 3) {		dev_err(&client->dev, "%s: diswe - %d\n", __FUNCTION__, xfer);		return -EIO;	}	return 0;}static int x1205_get_dtrim(struct i2c_client *client, int *trim){	unsigned char dtr;	static unsigned char dtr_addr[2] = { 0, X1205_REG_DTR };	struct i2c_msg msgs[] = {		{ client->addr, 0, 2, dtr_addr },	/* setup read ptr */		{ client->addr, I2C_M_RD, 1, &dtr }, 	/* read dtr */	};	/* read dtr register */	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 dtr=%x\n", __FUNCTION__, dtr);	*trim = 0;	if (dtr & X1205_DTR_DTR0)		*trim += 20;	if (dtr & X1205_DTR_DTR1)		*trim += 10;	if (dtr & X1205_DTR_DTR2)		*trim = -*trim;	return 0;}static int x1205_get_atrim(struct i2c_client *client, int *trim){