[linux.git] / drivers / rtc / rtc-x1205.c

/*
 * An i2c driver for the Xicor/Intersil X1205 RTC
 * Copyright 2004 Karen Spearel
 * Copyright 2005 Alessandro Zummo
 *
 * please send all reports to:
 * 	Karen Spearel <kas111 at gmail dot com>
 *	Alessandro Zummo <[email protected]>
 *
 * based on a lot of other RTC drivers.
 *
 * 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/bcd.h>
#include <linux/rtc.h>
#include <linux/delay.h>

#define DRV_VERSION "1.0.7"

/* 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;

/* 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 struct i2c_driver x1205_driver = {
	.driver		= {
		.name	= "x1205",
	},
	.id		= I2C_DRIVERID_X1205,
	.attach_adapter = &x1205_attach,
	.detach_client	= &x1205_detach,
};

/*
 * 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,
				unsigned char reg_base)
{
	unsigned char dt_addr[2] = { 0, reg_base };

	unsigned char buf[8];

	struct i2c_msg msgs[] = {
		{ client->addr, 0, 2, dt_addr },	/* setup read ptr */
		{ client->addr, I2C_M_RD, 8, 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 - 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]) - 1; /* mon is 0-11 */
	tm->tm_year = BCD2BIN(buf[CCR_YEAR])
			+ (BCD2BIN(buf[CCR_Y2K]) * 100) - 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_get_status(struct i2c_client *client, unsigned char *sr)
{
	static unsigned char sr_addr[2] = { 0, X1205_REG_SR };

	struct i2c_msg msgs[] = {
		{ client->addr, 0, 2, sr_addr },	/* setup read ptr */
		{ client->addr, I2C_M_RD, 1, sr },	/* read status */
	};

	/* read status register */
	if ((i2c_transfer(client->adapter, &msgs[0], 2)) != 2) {
		dev_err(&client->dev, "%s: read error\n", __FUNCTION__);
		return -EIO;
	}

	return 0;
}

static int x1205_set_datetime(struct i2c_client *client, struct rtc_time *tm,
				int datetoo, u8 reg_base)
{
	int i, 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 };

	dev_dbg(&client->dev,
		"%s: secs=%d, mins=%d, hours=%d\n",
		__FUNCTION__,
		tm->tm_sec, tm->tm_min, tm->tm_hour);

	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) {
		dev_dbg(&client->dev,
			"%s: mday=%d, mon=%d, year=%d, wday=%d\n",
			__FUNCTION__,
			tm->tm_mday, tm->tm_mon, tm->tm_year, tm->tm_wday);

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

		/* month, 1 - 12 */
		buf[CCR_MONTH] = BIN2BCD(tm->tm_mon + 1);

		/* year, since the rtc epoch*/
		buf[CCR_YEAR] = BIN2BCD(tm->tm_year % 100);
		buf[CCR_WDAY] = tm->tm_wday & 0x07;
		buf[CCR_Y2K] = BIN2BCD(tm->tm_year / 100);
	}

	/* this sequence is required to unlock the chip */
	if ((xfer = i2c_master_send(client, wel, 3)) != 3) {
		dev_err(&client->dev, "%s: wel - %d\n", __FUNCTION__, xfer);
		return -EIO;
	}

	if ((xfer = i2c_master_send(client, rwel, 3)) != 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 */
	if ((xfer = i2c_master_send(client, diswe, 3)) != 3) {
		dev_err(&client->dev, "%s: diswe - %d\n", __FUNCTION__, xfer);
		return -EIO;
	}

	return 0;
}

static int x1205_fix_osc(struct i2c_client *client)
{
	int err;
	struct rtc_time tm;

	tm.tm_hour = tm.tm_min = tm.tm_sec = 0;

	if ((err = x1205_set_datetime(client, &tm, 0, X1205_CCR_BASE)) < 0)
		dev_err(&client->dev,
			"unable to restart the oscillator\n");

	return err;
}

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)
{
	s8 atr;
	static unsigned char atr_addr[2] = { 0, X1205_REG_ATR };

	struct i2c_msg msgs[] = {
		{ client->addr, 0, 2, atr_addr },	/* setup read ptr */
		{ client->addr, I2C_M_RD, 1, &atr }, 	/* read atr */
	};

	/* read atr 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 atr=%x\n", __FUNCTION__, atr);

	/* atr is a two's complement value on 6 bits,
	 * perform sign extension. The formula is
	 * Catr = (atr * 0.25pF) + 11.00pF.
	 */
	if (atr & 0x20)
		atr |= 0xC0;

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

	*trim = (atr * 250) + 11000;

	dev_dbg(&client->dev, "%s: real=%d\n", __FUNCTION__, *trim);

	return 0;
}

struct x1205_limit
{
	unsigned char reg, mask, min, max;
};

static int x1205_validate_client(struct i2c_client *client)
{
	int i, xfer;

	/* Probe array. We will read the register at the specified
	 * address and check if the given bits are zero.
	 */
	static const unsigned char probe_zero_pattern[] = {
		/* register, mask */
		X1205_REG_SR,	0x18,
		X1205_REG_DTR,	0xF8,
		X1205_REG_ATR,	0xC0,
		X1205_REG_INT,	0x18,
		X1205_REG_0,	0xFF,
	};

	static const struct x1205_limit probe_limits_pattern[] = {
		/* register, mask, min, max */
		{ X1205_REG_Y2K,	0xFF,	19,	20	},
		{ X1205_REG_DW,		0xFF,	0,	6	},
		{ X1205_REG_YR,		0xFF,	0,	99	},
		{ X1205_REG_MO,		0xFF,	0,	12	},
		{ X1205_REG_DT,		0xFF,	0,	31	},
		{ X1205_REG_HR,		0x7F,	0,	23	},
		{ X1205_REG_MN,		0xFF,	0,	59	},
		{ X1205_REG_SC,		0xFF,	0,	59	},
		{ X1205_REG_Y2K1,	0xFF,	19,	20	},
		{ X1205_REG_Y2K0,	0xFF,	19,	20	},
	};

	/* check that registers have bits a 0 where expected */
	for (i = 0; i < ARRAY_SIZE(probe_zero_pattern); i += 2) {
		unsigned char buf;

		unsigned char addr[2] = { 0, probe_zero_pattern[i] };

		struct i2c_msg msgs[2] = {
			{ client->addr, 0, 2, addr },
			{ client->addr, I2C_M_RD, 1, &buf },
		};

		if ((xfer = i2c_transfer(client->adapter, msgs, 2)) != 2) {
			dev_err(&client->dev,
				"%s: could not read register %x\n",
				__FUNCTION__, probe_zero_pattern[i]);

			return -EIO;
		}

		if ((buf & probe_zero_pattern[i+1]) != 0) {
			dev_err(&client->dev,
				"%s: register=%02x, zero pattern=%d, value=%x\n",
				__FUNCTION__, probe_zero_pattern[i], i, buf);

			return -ENODEV;
		}
	}

	/* check limits (only registers with bcd values) */
	for (i = 0; i < ARRAY_SIZE(probe_limits_pattern); i++) {
		unsigned char reg, value;

		unsigned char addr[2] = { 0, probe_limits_pattern[i].reg };

		struct i2c_msg msgs[2] = {
			{ client->addr, 0, 2, addr },
			{ client->addr, I2C_M_RD, 1, &reg },
		};

		if ((xfer = i2c_transfer(client->adapter, msgs, 2)) != 2) {
			dev_err(&client->dev,
				"%s: could not read register %x\n",
				__FUNCTION__, probe_limits_pattern[i].reg);

			return -EIO;
		}

		value = BCD2BIN(reg & probe_limits_pattern[i].mask);

		if (value > probe_limits_pattern[i].max ||
			value < probe_limits_pattern[i].min) {
			dev_dbg(&client->dev,
				"%s: register=%x, lim pattern=%d, value=%d\n",
				__FUNCTION__, probe_limits_pattern[i].reg,
				i, value);

			return -ENODEV;
		}
	}

	return 0;
}

static int x1205_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alrm)
{
	return x1205_get_datetime(to_i2c_client(dev),
		&alrm->time, X1205_ALM0_BASE);
}

static int x1205_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm)
{
	return x1205_set_datetime(to_i2c_client(dev),
		&alrm->time, 1, X1205_ALM0_BASE);
}

static int x1205_rtc_read_time(struct device *dev, struct rtc_time *tm)
{
	return x1205_get_datetime(to_i2c_client(dev),
		tm, X1205_CCR_BASE);
}

static int x1205_rtc_set_time(struct device *dev, struct rtc_time *tm)
{
	return x1205_set_datetime(to_i2c_client(dev),
		tm, 1, X1205_CCR_BASE);
}

static int x1205_rtc_proc(struct device *dev, struct seq_file *seq)
{
	int err, dtrim, atrim;

	if ((err = x1205_get_dtrim(to_i2c_client(dev), &dtrim)) == 0)
		seq_printf(seq, "digital_trim\t: %d ppm\n", dtrim);

	if ((err = x1205_get_atrim(to_i2c_client(dev), &atrim)) == 0)
		seq_printf(seq, "analog_trim\t: %d.%02d pF\n",
			atrim / 1000, atrim % 1000);
	return 0;
}

static const struct rtc_class_ops x1205_rtc_ops = {
	.proc		= x1205_rtc_proc,
	.read_time	= x1205_rtc_read_time,
	.set_time	= x1205_rtc_set_time,
	.read_alarm	= x1205_rtc_read_alarm,
	.set_alarm	= x1205_rtc_set_alarm,
};

static ssize_t x1205_sysfs_show_atrim(struct device *dev,
				struct device_attribute *attr, char *buf)
{
	int err, atrim;

	err = x1205_get_atrim(to_i2c_client(dev), &atrim);
	if (err)
		return err;

	return sprintf(buf, "%d.%02d pF\n", atrim / 1000, atrim % 1000);
}
static DEVICE_ATTR(atrim, S_IRUGO, x1205_sysfs_show_atrim, NULL);

static ssize_t x1205_sysfs_show_dtrim(struct device *dev,
				struct device_attribute *attr, char *buf)
{
	int err, dtrim;

	err = x1205_get_dtrim(to_i2c_client(dev), &dtrim);
	if (err)
		return err;

	return sprintf(buf, "%d ppm\n", dtrim);
}
static DEVICE_ATTR(dtrim, S_IRUGO, x1205_sysfs_show_dtrim, NULL);

static int x1205_attach(struct i2c_adapter *adapter)
{
	return i2c_probe(adapter, &addr_data, x1205_probe);
}

static int x1205_probe(struct i2c_adapter *adapter, int address, int kind)
{
	int err = 0;
	unsigned char sr;
	struct i2c_client *client;
	struct rtc_device *rtc;

	dev_dbg(adapter->class_dev.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 = &x1205_driver;
	client->adapter	= adapter;

	strlcpy(client->name, x1205_driver.driver.name, I2C_NAME_SIZE);

	/* Verify the chip is really an X1205 */
	if (kind < 0) {
		if (x1205_validate_client(client) < 0) {
			err = -ENODEV;
			goto exit_kfree;
		}
	}

	/* 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(x1205_driver.driver.name, &client->dev,
				&x1205_rtc_ops, THIS_MODULE);

	if (IS_ERR(rtc)) {
		err = PTR_ERR(rtc);
		goto exit_detach;
	}

	i2c_set_clientdata(client, rtc);

	/* Check for power failures and eventualy enable the osc */
	if ((err = x1205_get_status(client, &sr)) == 0) {
		if (sr & X1205_SR_RTCF) {
			dev_err(&client->dev,
				"power failure detected, "
				"please set the clock\n");
			udelay(50);
			x1205_fix_osc(client);
		}
	}
	else
		dev_err(&client->dev, "couldn't read status\n");

	err = device_create_file(&client->dev, &dev_attr_atrim);
	if (err) goto exit_devreg;
	err = device_create_file(&client->dev, &dev_attr_dtrim);
	if (err) goto exit_atrim;

	return 0;

exit_atrim:
	device_remove_file(&client->dev, &dev_attr_atrim);

exit_devreg:
	rtc_device_unregister(rtc);

exit_detach:
	i2c_detach_client(client);

exit_kfree:
	kfree(client);

exit:
	return err;
}

static int x1205_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 int __init x1205_init(void)
{
	return i2c_add_driver(&x1205_driver);
}

static void __exit x1205_exit(void)
{
	i2c_del_driver(&x1205_driver);
}

MODULE_AUTHOR(
	"Karen Spearel <kas111 at gmail dot com>, "
	"Alessandro Zummo <[email protected]>");
MODULE_DESCRIPTION("Xicor/Intersil X1205 RTC driver");
MODULE_LICENSE("GPL");
MODULE_VERSION(DRV_VERSION);

module_init(x1205_init);
module_exit(x1205_exit);
Commit	Line	Data
1fec7c66 AZ	1	/*
	2	* An i2c driver for the Xicor/Intersil X1205 RTC
	3	* Copyright 2004 Karen Spearel
	4	* Copyright 2005 Alessandro Zummo
	5	*
	6	* please send all reports to:
	7	* Karen Spearel <kas111 at gmail dot com>
	8	* Alessandro Zummo <[email protected]>
	9	*
	10	* based on a lot of other RTC drivers.
	11	*
	12	* This program is free software; you can redistribute it and/or modify
	13	* it under the terms of the GNU General Public License version 2 as
	14	* published by the Free Software Foundation.
	15	*/
	16
	17	#include <linux/i2c.h>
	18	#include <linux/bcd.h>
	19	#include <linux/rtc.h>
	20	#include <linux/delay.h>
	21
015aefbb	22	#define DRV_VERSION "1.0.7"
1fec7c66 AZ	23
	24	/* Addresses to scan: none. This chip is located at
	25	* 0x6f and uses a two bytes register addressing.
	26	* Two bytes need to be written to read a single register,
	27	* while most other chips just require one and take the second
	28	* one as the data to be written. To prevent corrupting
	29	* unknown chips, the user must explicitely set the probe parameter.
	30	*/
	31
	32	static unsigned short normal_i2c[] = { I2C_CLIENT_END };
	33
	34	/* Insmod parameters */
	35	I2C_CLIENT_INSMOD;
	36
	37	/* offsets into CCR area */
	38
	39	#define CCR_SEC 0
	40	#define CCR_MIN 1
	41	#define CCR_HOUR 2
	42	#define CCR_MDAY 3
	43	#define CCR_MONTH 4
	44	#define CCR_YEAR 5
	45	#define CCR_WDAY 6
	46	#define CCR_Y2K 7
	47
	48	#define X1205_REG_SR 0x3F /* status register */
	49	#define X1205_REG_Y2K 0x37
	50	#define X1205_REG_DW 0x36
	51	#define X1205_REG_YR 0x35
	52	#define X1205_REG_MO 0x34
	53	#define X1205_REG_DT 0x33
	54	#define X1205_REG_HR 0x32
	55	#define X1205_REG_MN 0x31
	56	#define X1205_REG_SC 0x30
	57	#define X1205_REG_DTR 0x13
	58	#define X1205_REG_ATR 0x12
	59	#define X1205_REG_INT 0x11
	60	#define X1205_REG_0 0x10
	61	#define X1205_REG_Y2K1 0x0F
	62	#define X1205_REG_DWA1 0x0E
	63	#define X1205_REG_YRA1 0x0D
	64	#define X1205_REG_MOA1 0x0C
	65	#define X1205_REG_DTA1 0x0B
	66	#define X1205_REG_HRA1 0x0A
	67	#define X1205_REG_MNA1 0x09
	68	#define X1205_REG_SCA1 0x08
	69	#define X1205_REG_Y2K0 0x07
	70	#define X1205_REG_DWA0 0x06
	71	#define X1205_REG_YRA0 0x05
	72	#define X1205_REG_MOA0 0x04
	73	#define X1205_REG_DTA0 0x03
	74	#define X1205_REG_HRA0 0x02
	75	#define X1205_REG_MNA0 0x01
	76	#define X1205_REG_SCA0 0x00
	77
	78	#define X1205_CCR_BASE 0x30 /* Base address of CCR */
	79	#define X1205_ALM0_BASE 0x00 /* Base address of ALARM0 */
	80
	81	#define X1205_SR_RTCF 0x01 /* Clock failure */
	82	#define X1205_SR_WEL 0x02 /* Write Enable Latch */
	83	#define X1205_SR_RWEL 0x04 /* Register Write Enable */
	84
	85	#define X1205_DTR_DTR0 0x01
	86	#define X1205_DTR_DTR1 0x02
87	#define X1205_DTR_DTR2 0x04
88
89	#define X1205_HR_MIL 0x80 /* Set in ccr.hour for 24 hr mode */
90
91	/* Prototypes */
92	static int x1205_attach(struct i2c_adapter *adapter);
93	static int x1205_detach(struct i2c_client *client);
94	static int x1205_probe(struct i2c_adapter *adapter, int address, int kind);
95
96	static struct i2c_driver x1205_driver = {
97	.driver = {
98	.name = "x1205",
99	},
100	.id = I2C_DRIVERID_X1205,
101	.attach_adapter = &x1205_attach,
102	.detach_client = &x1205_detach,
103	};
104
105	/*
106	* In the routines that deal directly with the x1205 hardware, we use
107	* rtc_time -- month 0-11, hour 0-23, yr = calendar year-epoch
108	* Epoch is initialized as 2000. Time is set to UTC.
109	*/
110	static int x1205_get_datetime(struct i2c_client client, struct rtc_time tm,
111	unsigned char reg_base)
112	{
113	unsigned char dt_addr[2] = { 0, reg_base };
114
115	unsigned char buf[8];
116
117	struct i2c_msg msgs[] = {
118	{ client->addr, 0, 2, dt_addr }, /* setup read ptr */
119	{ client->addr, I2C_M_RD, 8, buf }, /* read date */
120	};
121
122	/* read date registers */
123	if ((i2c_transfer(client->adapter, &msgs[0], 2)) != 2) {
124	dev_err(&client->dev, "%s: read error\n", __FUNCTION__);
125	return -EIO;
126	}
127
128	dev_dbg(&client->dev,
129	"%s: raw read data - sec=%02x, min=%02x, hr=%02x, "
130	"mday=%02x, mon=%02x, year=%02x, wday=%02x, y2k=%02x\n",
131	__FUNCTION__,
132	buf[0], buf[1], buf[2], buf[3],
133	buf[4], buf[5], buf[6], buf[7]);
134
135	tm->tm_sec = BCD2BIN(buf[CCR_SEC]);
136	tm->tm_min = BCD2BIN(buf[CCR_MIN]);
137	tm->tm_hour = BCD2BIN(buf[CCR_HOUR] & 0x3F); /* hr is 0-23 */
138	tm->tm_mday = BCD2BIN(buf[CCR_MDAY]);
139	tm->tm_mon = BCD2BIN(buf[CCR_MONTH]) - 1; /* mon is 0-11 */
140	tm->tm_year = BCD2BIN(buf[CCR_YEAR])
141	+ (BCD2BIN(buf[CCR_Y2K]) * 100) - 1900;
142	tm->tm_wday = buf[CCR_WDAY];
143
144	dev_dbg(&client->dev, "%s: tm is secs=%d, mins=%d, hours=%d, "
145	"mday=%d, mon=%d, year=%d, wday=%d\n",
146	__FUNCTION__,
147	tm->tm_sec, tm->tm_min, tm->tm_hour,
148	tm->tm_mday, tm->tm_mon, tm->tm_year, tm->tm_wday);
149
150	return 0;
151	}
152
153	static int x1205_get_status(struct i2c_client client, unsigned char sr)
154	{
155	static unsigned char sr_addr[2] = { 0, X1205_REG_SR };
156
157	struct i2c_msg msgs[] = {
158	{ client->addr, 0, 2, sr_addr }, /* setup read ptr */
159	{ client->addr, I2C_M_RD, 1, sr }, /* read status */
160	};
161
162	/* read status register */
163	if ((i2c_transfer(client->adapter, &msgs[0], 2)) != 2) {
164	dev_err(&client->dev, "%s: read error\n", __FUNCTION__);
165	return -EIO;
166	}
167
168	return 0;
169	}
170
171	static int x1205_set_datetime(struct i2c_client client, struct rtc_time tm,
172	int datetoo, u8 reg_base)
173	{
174	int i, xfer;
175	unsigned char buf[8];
176
177	static const unsigned char wel[3] = { 0, X1205_REG_SR,
178	X1205_SR_WEL };
179
180	static const unsigned char rwel[3] = { 0, X1205_REG_SR,
181	X1205_SR_WEL \| X1205_SR_RWEL };
182
183	static const unsigned char diswe[3] = { 0, X1205_REG_SR, 0 };
184
185	dev_dbg(&client->dev,
186	"%s: secs=%d, mins=%d, hours=%d\n",
187	__FUNCTION__,
188	tm->tm_sec, tm->tm_min, tm->tm_hour);
189
190	buf[CCR_SEC] = BIN2BCD(tm->tm_sec);
191	buf[CCR_MIN] = BIN2BCD(tm->tm_min);
192
193	/* set hour and 24hr bit */
194	buf[CCR_HOUR] = BIN2BCD(tm->tm_hour) \| X1205_HR_MIL;
195
196	/* should we also set the date? */
197	if (datetoo) {
198	dev_dbg(&client->dev,
199	"%s: mday=%d, mon=%d, year=%d, wday=%d\n",
200	__FUNCTION__,
201	tm->tm_mday, tm->tm_mon, tm->tm_year, tm->tm_wday);
202
203	buf[CCR_MDAY] = BIN2BCD(tm->tm_mday);
204
205	/* month, 1 - 12 */
206	buf[CCR_MONTH] = BIN2BCD(tm->tm_mon + 1);
207
208	/* year, since the rtc epoch*/
209	buf[CCR_YEAR] = BIN2BCD(tm->tm_year % 100);
210	buf[CCR_WDAY] = tm->tm_wday & 0x07;
211	buf[CCR_Y2K] = BIN2BCD(tm->tm_year / 100);
212	}
213
214	/* this sequence is required to unlock the chip */
215	if ((xfer = i2c_master_send(client, wel, 3)) != 3) {
216	dev_err(&client->dev, "%s: wel - %d\n", __FUNCTION__, xfer);
217	return -EIO;
218	}
219
220	if ((xfer = i2c_master_send(client, rwel, 3)) != 3) {
221	dev_err(&client->dev, "%s: rwel - %d\n", __FUNCTION__, xfer);
222	return -EIO;
223	}
224
225	/* write register's data */
226	for (i = 0; i < (datetoo ? 8 : 3); i++) {
227	unsigned char rdata[3] = { 0, reg_base + i, buf[i] };
228
229	xfer = i2c_master_send(client, rdata, 3);
230	if (xfer != 3) {
231	dev_err(&client->dev,
232	"%s: xfer=%d addr=%02x, data=%02x\n",
233	__FUNCTION__,
234	xfer, rdata[1], rdata[2]);
235	return -EIO;
236	}
237	};
238
239	/* disable further writes */
240	if ((xfer = i2c_master_send(client, diswe, 3)) != 3) {
241	dev_err(&client->dev, "%s: diswe - %d\n", __FUNCTION__, xfer);
242	return -EIO;
243	}
244
245	return 0;
246	}
247
248	static int x1205_fix_osc(struct i2c_client *client)
249	{
250	int err;
251	struct rtc_time tm;
252
253	tm.tm_hour = tm.tm_min = tm.tm_sec = 0;
254
255	if ((err = x1205_set_datetime(client, &tm, 0, X1205_CCR_BASE)) < 0)
256	dev_err(&client->dev,
257	"unable to restart the oscillator\n");
258
259	return err;
260	}
261
262	static int x1205_get_dtrim(struct i2c_client client, int trim)
263	{
264	unsigned char dtr;
265	static unsigned char dtr_addr[2] = { 0, X1205_REG_DTR };
266
267	struct i2c_msg msgs[] = {
268	{ client->addr, 0, 2, dtr_addr }, /* setup read ptr */
269	{ client->addr, I2C_M_RD, 1, &dtr }, /* read dtr */
270	};
271
272	/* read dtr register */
273	if ((i2c_transfer(client->adapter, &msgs[0], 2)) != 2) {
274	dev_err(&client->dev, "%s: read error\n", __FUNCTION__);
275	return -EIO;
276	}
277
278	dev_dbg(&client->dev, "%s: raw dtr=%x\n", __FUNCTION__, dtr);
279
280	*trim = 0;
281
282	if (dtr & X1205_DTR_DTR0)
283	*trim += 20;
284
285	if (dtr & X1205_DTR_DTR1)
286	*trim += 10;
287
288	if (dtr & X1205_DTR_DTR2)
289	trim = -trim;
290
291	return 0;
292	}
293
294	static int x1205_get_atrim(struct i2c_client client, int trim)
295	{
296	s8 atr;
297	static unsigned char atr_addr[2] = { 0, X1205_REG_ATR };
298
299	struct i2c_msg msgs[] = {
300	{ client->addr, 0, 2, atr_addr }, /* setup read ptr */
301	{ client->addr, I2C_M_RD, 1, &atr }, /* read atr */
302	};
303
304	/* read atr register */
305	if ((i2c_transfer(client->adapter, &msgs[0], 2)) != 2) {
306	dev_err(&client->dev, "%s: read error\n", __FUNCTION__);
307	return -EIO;
308	}
309
310	dev_dbg(&client->dev, "%s: raw atr=%x\n", __FUNCTION__, atr);
311
312	/* atr is a two's complement value on 6 bits,
313	* perform sign extension. The formula is
314	* Catr = (atr * 0.25pF) + 11.00pF.
315	*/
316	if (atr & 0x20)
317	atr \|= 0xC0;
318
319	dev_dbg(&client->dev, "%s: raw atr=%x (%d)\n", __FUNCTION__, atr, atr);
320
321	trim = (atr 250) + 11000;
322
323	dev_dbg(&client->dev, "%s: real=%d\n", __FUNCTION__, *trim);
324
325	return 0;
326	}
327
328	struct x1205_limit
329	{
330	unsigned char reg, mask, min, max;
331	};
332
333	static int x1205_validate_client(struct i2c_client *client)
334	{
335	int i, xfer;
336
337	/* Probe array. We will read the register at the specified
338	* address and check if the given bits are zero.
339	*/
340	static const unsigned char probe_zero_pattern[] = {
341	/* register, mask */
342	X1205_REG_SR, 0x18,
343	X1205_REG_DTR, 0xF8,
344	X1205_REG_ATR, 0xC0,
345	X1205_REG_INT, 0x18,
346	X1205_REG_0, 0xFF,
347	};
348
349	static const struct x1205_limit probe_limits_pattern[] = {
350	/* register, mask, min, max */
351	{ X1205_REG_Y2K, 0xFF, 19, 20 },
352	{ X1205_REG_DW, 0xFF, 0, 6 },
353	{ X1205_REG_YR, 0xFF, 0, 99 },
354	{ X1205_REG_MO, 0xFF, 0, 12 },
355	{ X1205_REG_DT, 0xFF, 0, 31 },
356	{ X1205_REG_HR, 0x7F, 0, 23 },
357	{ X1205_REG_MN, 0xFF, 0, 59 },
358	{ X1205_REG_SC, 0xFF, 0, 59 },
359	{ X1205_REG_Y2K1, 0xFF, 19, 20 },
360	{ X1205_REG_Y2K0, 0xFF, 19, 20 },
361	};
362
363	/* check that registers have bits a 0 where expected */
364	for (i = 0; i < ARRAY_SIZE(probe_zero_pattern); i += 2) {
365	unsigned char buf;
366
367	unsigned char addr[2] = { 0, probe_zero_pattern[i] };
368
369	struct i2c_msg msgs[2] = {
370	{ client->addr, 0, 2, addr },
371	{ client->addr, I2C_M_RD, 1, &buf },
372	};
373
374	if ((xfer = i2c_transfer(client->adapter, msgs, 2)) != 2) {
a14e1893	375	dev_err(&client->dev,
1fec7c66 AZ	376	"%s: could not read register %x\n",
	377	__FUNCTION__, probe_zero_pattern[i]);
	378
	379	return -EIO;
	380	}
	381
	382	if ((buf & probe_zero_pattern[i+1]) != 0) {
a14e1893	383	dev_err(&client->dev,
1fec7c66 AZ	384	"%s: register=%02x, zero pattern=%d, value=%x\n",
	385	__FUNCTION__, probe_zero_pattern[i], i, buf);
	386
	387	return -ENODEV;
	388	}
	389	}
	390
	391	/* check limits (only registers with bcd values) */
	392	for (i = 0; i < ARRAY_SIZE(probe_limits_pattern); i++) {
	393	unsigned char reg, value;
	394
	395	unsigned char addr[2] = { 0, probe_limits_pattern[i].reg };
	396
	397	struct i2c_msg msgs[2] = {
	398	{ client->addr, 0, 2, addr },
	399	{ client->addr, I2C_M_RD, 1, &reg },
	400	};
	401
	402	if ((xfer = i2c_transfer(client->adapter, msgs, 2)) != 2) {
a14e1893	403	dev_err(&client->dev,
1fec7c66 AZ	404	"%s: could not read register %x\n",
	405	__FUNCTION__, probe_limits_pattern[i].reg);
	406
	407	return -EIO;
	408	}
	409
	410	value = BCD2BIN(reg & probe_limits_pattern[i].mask);
	411
	412	if (value > probe_limits_pattern[i].max \|\|
	413	value < probe_limits_pattern[i].min) {
a14e1893	414	dev_dbg(&client->dev,
1fec7c66 AZ	415	"%s: register=%x, lim pattern=%d, value=%d\n",
	416	__FUNCTION__, probe_limits_pattern[i].reg,
	417	i, value);
	418
	419	return -ENODEV;
	420	}
	421	}
	422
	423	return 0;
	424	}
	425
	426	static int x1205_rtc_read_alarm(struct device dev, struct rtc_wkalrm alrm)
	427	{
	428	return x1205_get_datetime(to_i2c_client(dev),
	429	&alrm->time, X1205_ALM0_BASE);
	430	}
	431
	432	static int x1205_rtc_set_alarm(struct device dev, struct rtc_wkalrm alrm)
	433	{
	434	return x1205_set_datetime(to_i2c_client(dev),
	435	&alrm->time, 1, X1205_ALM0_BASE);
	436	}
	437
	438	static int x1205_rtc_read_time(struct device dev, struct rtc_time tm)
	439	{
	440	return x1205_get_datetime(to_i2c_client(dev),
	441	tm, X1205_CCR_BASE);
	442	}
	443
	444	static int x1205_rtc_set_time(struct device dev, struct rtc_time tm)
	445	{
	446	return x1205_set_datetime(to_i2c_client(dev),
	447	tm, 1, X1205_CCR_BASE);
	448	}
	449
	450	static int x1205_rtc_proc(struct device dev, struct seq_file seq)
	451	{
	452	int err, dtrim, atrim;
	453
1fec7c66 AZ	454	if ((err = x1205_get_dtrim(to_i2c_client(dev), &dtrim)) == 0)
	455	seq_printf(seq, "digital_trim\t: %d ppm\n", dtrim);
	456
	457	if ((err = x1205_get_atrim(to_i2c_client(dev), &atrim)) == 0)
	458	seq_printf(seq, "analog_trim\t: %d.%02d pF\n",
	459	atrim / 1000, atrim % 1000);
	460	return 0;
	461	}
	462
ff8371ac	463	static const struct rtc_class_ops x1205_rtc_ops = {
1fec7c66 AZ	464	.proc = x1205_rtc_proc,
	465	.read_time = x1205_rtc_read_time,
	466	.set_time = x1205_rtc_set_time,
	467	.read_alarm = x1205_rtc_read_alarm,
	468	.set_alarm = x1205_rtc_set_alarm,
	469	};
	470
	471	static ssize_t x1205_sysfs_show_atrim(struct device *dev,
	472	struct device_attribute attr, char buf)
	473	{
015aefbb	474	int err, atrim;
1fec7c66	475
015aefbb AZ	476	err = x1205_get_atrim(to_i2c_client(dev), &atrim);
	477	if (err)
	478	return err;
	479
	480	return sprintf(buf, "%d.%02d pF\n", atrim / 1000, atrim % 1000);
1fec7c66 AZ	481	}
	482	static DEVICE_ATTR(atrim, S_IRUGO, x1205_sysfs_show_atrim, NULL);
	483
	484	static ssize_t x1205_sysfs_show_dtrim(struct device *dev,
	485	struct device_attribute attr, char buf)
	486	{
015aefbb	487	int err, dtrim;
1fec7c66	488
015aefbb AZ	489	err = x1205_get_dtrim(to_i2c_client(dev), &dtrim);
	490	if (err)
	491	return err;
1fec7c66	492
015aefbb	493	return sprintf(buf, "%d ppm\n", dtrim);
1fec7c66 AZ	494	}
	495	static DEVICE_ATTR(dtrim, S_IRUGO, x1205_sysfs_show_dtrim, NULL);
	496
	497	static int x1205_attach(struct i2c_adapter *adapter)
	498	{
1fec7c66 AZ	499	return i2c_probe(adapter, &addr_data, x1205_probe);
	500	}
	501
	502	static int x1205_probe(struct i2c_adapter *adapter, int address, int kind)
	503	{
	504	int err = 0;
	505	unsigned char sr;
	506	struct i2c_client *client;
	507	struct rtc_device *rtc;
	508
a14e1893	509	dev_dbg(adapter->class_dev.dev, "%s\n", __FUNCTION__);
1fec7c66 AZ	510
	511	if (!i2c_check_functionality(adapter, I2C_FUNC_I2C)) {
	512	err = -ENODEV;
	513	goto exit;
	514	}
	515
	516	if (!(client = kzalloc(sizeof(struct i2c_client), GFP_KERNEL))) {
	517	err = -ENOMEM;
	518	goto exit;
	519	}
	520
	521	/* I2C client */
	522	client->addr = address;
	523	client->driver = &x1205_driver;
	524	client->adapter = adapter;
	525
	526	strlcpy(client->name, x1205_driver.driver.name, I2C_NAME_SIZE);
	527
	528	/* Verify the chip is really an X1205 */
	529	if (kind < 0) {
	530	if (x1205_validate_client(client) < 0) {
	531	err = -ENODEV;
	532	goto exit_kfree;
	533	}
	534	}
	535
	536	/* Inform the i2c layer */
	537	if ((err = i2c_attach_client(client)))
	538	goto exit_kfree;
	539
	540	dev_info(&client->dev, "chip found, driver version " DRV_VERSION "\n");
	541
	542	rtc = rtc_device_register(x1205_driver.driver.name, &client->dev,
	543	&x1205_rtc_ops, THIS_MODULE);
	544
	545	if (IS_ERR(rtc)) {
	546	err = PTR_ERR(rtc);
1fec7c66 AZ	547	goto exit_detach;
	548	}
	549
	550	i2c_set_clientdata(client, rtc);
	551
	552	/* Check for power failures and eventualy enable the osc */
	553	if ((err = x1205_get_status(client, &sr)) == 0) {
	554	if (sr & X1205_SR_RTCF) {
	555	dev_err(&client->dev,
	556	"power failure detected, "
	557	"please set the clock\n");
	558	udelay(50);
	559	x1205_fix_osc(client);
	560	}
	561	}
	562	else
	563	dev_err(&client->dev, "couldn't read status\n");
	564
91046a8a JG	565	err = device_create_file(&client->dev, &dev_attr_atrim);
	566	if (err) goto exit_devreg;
	567	err = device_create_file(&client->dev, &dev_attr_dtrim);
	568	if (err) goto exit_atrim;
1fec7c66 AZ	569
	570	return 0;
	571
91046a8a JG	572	exit_atrim:
	573	device_remove_file(&client->dev, &dev_attr_atrim);
	574
	575	exit_devreg:
	576	rtc_device_unregister(rtc);
	577
1fec7c66 AZ	578	exit_detach:
	579	i2c_detach_client(client);
	580
	581	exit_kfree:
	582	kfree(client);
	583
	584	exit:
	585	return err;
	586	}
	587
	588	static int x1205_detach(struct i2c_client *client)
	589	{
	590	int err;
	591	struct rtc_device *rtc = i2c_get_clientdata(client);
	592
1fec7c66 AZ	593	if (rtc)
	594	rtc_device_unregister(rtc);
	595
	596	if ((err = i2c_detach_client(client)))
	597	return err;
	598
	599	kfree(client);
	600
	601	return 0;
	602	}
	603
	604	static int __init x1205_init(void)
	605	{
	606	return i2c_add_driver(&x1205_driver);
	607	}
	608
	609	static void __exit x1205_exit(void)
	610	{
	611	i2c_del_driver(&x1205_driver);
	612	}
	613
	614	MODULE_AUTHOR(
	615	"Karen Spearel <kas111 at gmail dot com>, "
	616	"Alessandro Zummo <[email protected]>");
	617	MODULE_DESCRIPTION("Xicor/Intersil X1205 RTC driver");
	618	MODULE_LICENSE("GPL");
	619	MODULE_VERSION(DRV_VERSION);
	620
	621	module_init(x1205_init);
	622	module_exit(x1205_exit);