[linux-2.6-block.git] / drivers / rtc / rtc-isl1208.c

/*
 * Intersil ISL1208 rtc class driver
 *
 * Copyright 2005,2006 Hebert Valerio Riedel <hvr@gnu.org>
 *
 *  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/i2c.h>
#include <linux/bcd.h>
#include <linux/rtc.h>

#define DRV_VERSION "0.3"

/* Register map */
/* rtc section */
#define ISL1208_REG_SC  0x00
#define ISL1208_REG_MN  0x01
#define ISL1208_REG_HR  0x02
#define ISL1208_REG_HR_MIL     (1<<7)	/* 24h/12h mode */
#define ISL1208_REG_HR_PM      (1<<5)	/* PM/AM bit in 12h mode */
#define ISL1208_REG_DT  0x03
#define ISL1208_REG_MO  0x04
#define ISL1208_REG_YR  0x05
#define ISL1208_REG_DW  0x06
#define ISL1208_RTC_SECTION_LEN 7

/* control/status section */
#define ISL1208_REG_SR  0x07
#define ISL1208_REG_SR_ARST    (1<<7)	/* auto reset */
#define ISL1208_REG_SR_XTOSCB  (1<<6)	/* crystal oscillator */
#define ISL1208_REG_SR_WRTC    (1<<4)	/* write rtc */
#define ISL1208_REG_SR_ALM     (1<<2)	/* alarm */
#define ISL1208_REG_SR_BAT     (1<<1)	/* battery */
#define ISL1208_REG_SR_RTCF    (1<<0)	/* rtc fail */
#define ISL1208_REG_INT 0x08
#define ISL1208_REG_09  0x09	/* reserved */
#define ISL1208_REG_ATR 0x0a
#define ISL1208_REG_DTR 0x0b

/* alarm section */
#define ISL1208_REG_SCA 0x0c
#define ISL1208_REG_MNA 0x0d
#define ISL1208_REG_HRA 0x0e
#define ISL1208_REG_DTA 0x0f
#define ISL1208_REG_MOA 0x10
#define ISL1208_REG_DWA 0x11
#define ISL1208_ALARM_SECTION_LEN 6

/* user section */
#define ISL1208_REG_USR1 0x12
#define ISL1208_REG_USR2 0x13
#define ISL1208_USR_SECTION_LEN 2

static struct i2c_driver isl1208_driver;

/* block read */
static int
isl1208_i2c_read_regs(struct i2c_client *client, u8 reg, u8 buf[],
		      unsigned len)
{
	u8 reg_addr[1] = { reg };
	struct i2c_msg msgs[2] = {
		{client->addr, 0, sizeof(reg_addr), reg_addr}
		,
		{client->addr, I2C_M_RD, len, buf}
	};
	int ret;

	BUG_ON(reg > ISL1208_REG_USR2);
	BUG_ON(reg + len > ISL1208_REG_USR2 + 1);

	ret = i2c_transfer(client->adapter, msgs, 2);
	if (ret > 0)
		ret = 0;
	return ret;
}

/* block write */
static int
isl1208_i2c_set_regs(struct i2c_client *client, u8 reg, u8 const buf[],
		     unsigned len)
{
	u8 i2c_buf[ISL1208_REG_USR2 + 2];
	struct i2c_msg msgs[1] = {
		{client->addr, 0, len + 1, i2c_buf}
	};
	int ret;

	BUG_ON(reg > ISL1208_REG_USR2);
	BUG_ON(reg + len > ISL1208_REG_USR2 + 1);

	i2c_buf[0] = reg;
	memcpy(&i2c_buf[1], &buf[0], len);

	ret = i2c_transfer(client->adapter, msgs, 1);
	if (ret > 0)
		ret = 0;
	return ret;
}

/* simple check to see wether we have a isl1208 */
static int
isl1208_i2c_validate_client(struct i2c_client *client)
{
	u8 regs[ISL1208_RTC_SECTION_LEN] = { 0, };
	u8 zero_mask[ISL1208_RTC_SECTION_LEN] = {
		0x80, 0x80, 0x40, 0xc0, 0xe0, 0x00, 0xf8
	};
	int i;
	int ret;

	ret = isl1208_i2c_read_regs(client, 0, regs, ISL1208_RTC_SECTION_LEN);
	if (ret < 0)
		return ret;

	for (i = 0; i < ISL1208_RTC_SECTION_LEN; ++i) {
		if (regs[i] & zero_mask[i])	/* check if bits are cleared */
			return -ENODEV;
	}

	return 0;
}

static int
isl1208_i2c_get_sr(struct i2c_client *client)
{
	int sr = i2c_smbus_read_byte_data(client, ISL1208_REG_SR);
	if (sr < 0)
		return -EIO;

	return sr;
}

static int
isl1208_i2c_get_atr(struct i2c_client *client)
{
	int atr = i2c_smbus_read_byte_data(client, ISL1208_REG_ATR);
	if (atr < 0)
		return atr;

	/* The 6bit value in the ATR register controls the load
	 * capacitance C_load * in steps of 0.25pF
	 *
	 * bit (1<<5) of the ATR register is inverted
	 *
	 * C_load(ATR=0x20) =  4.50pF
	 * C_load(ATR=0x00) = 12.50pF
	 * C_load(ATR=0x1f) = 20.25pF
	 *
	 */

	atr &= 0x3f;		/* mask out lsb */
	atr ^= 1 << 5;		/* invert 6th bit */
	atr += 2 * 9;		/* add offset of 4.5pF; unit[atr] = 0.25pF */

	return atr;
}

static int
isl1208_i2c_get_dtr(struct i2c_client *client)
{
	int dtr = i2c_smbus_read_byte_data(client, ISL1208_REG_DTR);
	if (dtr < 0)
		return -EIO;

	/* dtr encodes adjustments of {-60,-40,-20,0,20,40,60} ppm */
	dtr = ((dtr & 0x3) * 20) * (dtr & (1 << 2) ? -1 : 1);

	return dtr;
}

static int
isl1208_i2c_get_usr(struct i2c_client *client)
{
	u8 buf[ISL1208_USR_SECTION_LEN] = { 0, };
	int ret;

	ret = isl1208_i2c_read_regs(client, ISL1208_REG_USR1, buf,
				    ISL1208_USR_SECTION_LEN);
	if (ret < 0)
		return ret;

	return (buf[1] << 8) | buf[0];
}

static int
isl1208_i2c_set_usr(struct i2c_client *client, u16 usr)
{
	u8 buf[ISL1208_USR_SECTION_LEN];

	buf[0] = usr & 0xff;
	buf[1] = (usr >> 8) & 0xff;

	return isl1208_i2c_set_regs(client, ISL1208_REG_USR1, buf,
				    ISL1208_USR_SECTION_LEN);
}

static int
isl1208_rtc_proc(struct device *dev, struct seq_file *seq)
{
	struct i2c_client *const client = to_i2c_client(dev);
	int sr, dtr, atr, usr;

	sr = isl1208_i2c_get_sr(client);
	if (sr < 0) {
		dev_err(&client->dev, "%s: reading SR failed\n", __func__);
		return sr;
	}

	seq_printf(seq, "status_reg\t:%s%s%s%s%s%s (0x%.2x)\n",
		   (sr & ISL1208_REG_SR_RTCF) ? " RTCF" : "",
		   (sr & ISL1208_REG_SR_BAT) ? " BAT" : "",
		   (sr & ISL1208_REG_SR_ALM) ? " ALM" : "",
		   (sr & ISL1208_REG_SR_WRTC) ? " WRTC" : "",
		   (sr & ISL1208_REG_SR_XTOSCB) ? " XTOSCB" : "",
		   (sr & ISL1208_REG_SR_ARST) ? " ARST" : "", sr);

	seq_printf(seq, "batt_status\t: %s\n",
		   (sr & ISL1208_REG_SR_RTCF) ? "bad" : "okay");

	dtr = isl1208_i2c_get_dtr(client);
	if (dtr >= 0 - 1)
		seq_printf(seq, "digital_trim\t: %d ppm\n", dtr);

	atr = isl1208_i2c_get_atr(client);
	if (atr >= 0)
		seq_printf(seq, "analog_trim\t: %d.%.2d pF\n",
			   atr >> 2, (atr & 0x3) * 25);

	usr = isl1208_i2c_get_usr(client);
	if (usr >= 0)
		seq_printf(seq, "user_data\t: 0x%.4x\n", usr);

	return 0;
}

static int
isl1208_i2c_read_time(struct i2c_client *client, struct rtc_time *tm)
{
	int sr;
	u8 regs[ISL1208_RTC_SECTION_LEN] = { 0, };

	sr = isl1208_i2c_get_sr(client);
	if (sr < 0) {
		dev_err(&client->dev, "%s: reading SR failed\n", __func__);
		return -EIO;
	}

	sr = isl1208_i2c_read_regs(client, 0, regs, ISL1208_RTC_SECTION_LEN);
	if (sr < 0) {
		dev_err(&client->dev, "%s: reading RTC section failed\n",
			__func__);
		return sr;
	}

	tm->tm_sec = BCD2BIN(regs[ISL1208_REG_SC]);
	tm->tm_min = BCD2BIN(regs[ISL1208_REG_MN]);

	/* HR field has a more complex interpretation */
	{
		const u8 _hr = regs[ISL1208_REG_HR];
		if (_hr & ISL1208_REG_HR_MIL)	/* 24h format */
			tm->tm_hour = BCD2BIN(_hr & 0x3f);
		else {
			/* 12h format */
			tm->tm_hour = BCD2BIN(_hr & 0x1f);
			if (_hr & ISL1208_REG_HR_PM)	/* PM flag set */
				tm->tm_hour += 12;
		}
	}

	tm->tm_mday = BCD2BIN(regs[ISL1208_REG_DT]);
	tm->tm_mon = BCD2BIN(regs[ISL1208_REG_MO]) - 1;	/* rtc starts at 1 */
	tm->tm_year = BCD2BIN(regs[ISL1208_REG_YR]) + 100;
	tm->tm_wday = BCD2BIN(regs[ISL1208_REG_DW]);

	return 0;
}

static int
isl1208_i2c_read_alarm(struct i2c_client *client, struct rtc_wkalrm *alarm)
{
	struct rtc_time *const tm = &alarm->time;
	u8 regs[ISL1208_ALARM_SECTION_LEN] = { 0, };
	int sr;

	sr = isl1208_i2c_get_sr(client);
	if (sr < 0) {
		dev_err(&client->dev, "%s: reading SR failed\n", __func__);
		return sr;
	}

	sr = isl1208_i2c_read_regs(client, ISL1208_REG_SCA, regs,
				   ISL1208_ALARM_SECTION_LEN);
	if (sr < 0) {
		dev_err(&client->dev, "%s: reading alarm section failed\n",
			__func__);
		return sr;
	}

	/* MSB of each alarm register is an enable bit */
	tm->tm_sec = BCD2BIN(regs[ISL1208_REG_SCA - ISL1208_REG_SCA] & 0x7f);
	tm->tm_min = BCD2BIN(regs[ISL1208_REG_MNA - ISL1208_REG_SCA] & 0x7f);
	tm->tm_hour = BCD2BIN(regs[ISL1208_REG_HRA - ISL1208_REG_SCA] & 0x3f);
	tm->tm_mday = BCD2BIN(regs[ISL1208_REG_DTA - ISL1208_REG_SCA] & 0x3f);
	tm->tm_mon =
		BCD2BIN(regs[ISL1208_REG_MOA - ISL1208_REG_SCA] & 0x1f) - 1;
	tm->tm_wday = BCD2BIN(regs[ISL1208_REG_DWA - ISL1208_REG_SCA] & 0x03);

	return 0;
}

static int
isl1208_rtc_read_time(struct device *dev, struct rtc_time *tm)
{
	return isl1208_i2c_read_time(to_i2c_client(dev), tm);
}

static int
isl1208_i2c_set_time(struct i2c_client *client, struct rtc_time const *tm)
{
	int sr;
	u8 regs[ISL1208_RTC_SECTION_LEN] = { 0, };

	regs[ISL1208_REG_SC] = BIN2BCD(tm->tm_sec);
	regs[ISL1208_REG_MN] = BIN2BCD(tm->tm_min);
	regs[ISL1208_REG_HR] = BIN2BCD(tm->tm_hour) | ISL1208_REG_HR_MIL;

	regs[ISL1208_REG_DT] = BIN2BCD(tm->tm_mday);
	regs[ISL1208_REG_MO] = BIN2BCD(tm->tm_mon + 1);
	regs[ISL1208_REG_YR] = BIN2BCD(tm->tm_year - 100);

	regs[ISL1208_REG_DW] = BIN2BCD(tm->tm_wday & 7);

	sr = isl1208_i2c_get_sr(client);
	if (sr < 0) {
		dev_err(&client->dev, "%s: reading SR failed\n", __func__);
		return sr;
	}

	/* set WRTC */
	sr = i2c_smbus_write_byte_data(client, ISL1208_REG_SR,
				       sr | ISL1208_REG_SR_WRTC);
	if (sr < 0) {
		dev_err(&client->dev, "%s: writing SR failed\n", __func__);
		return sr;
	}

	/* write RTC registers */
	sr = isl1208_i2c_set_regs(client, 0, regs, ISL1208_RTC_SECTION_LEN);
	if (sr < 0) {
		dev_err(&client->dev, "%s: writing RTC section failed\n",
			__func__);
		return sr;
	}

	/* clear WRTC again */
	sr = i2c_smbus_write_byte_data(client, ISL1208_REG_SR,
				       sr & ~ISL1208_REG_SR_WRTC);
	if (sr < 0) {
		dev_err(&client->dev, "%s: writing SR failed\n", __func__);
		return sr;
	}

	return 0;
}


static int
isl1208_rtc_set_time(struct device *dev, struct rtc_time *tm)
{
	return isl1208_i2c_set_time(to_i2c_client(dev), tm);
}

static int
isl1208_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alarm)
{
	return isl1208_i2c_read_alarm(to_i2c_client(dev), alarm);
}

static const struct rtc_class_ops isl1208_rtc_ops = {
	.proc = isl1208_rtc_proc,
	.read_time = isl1208_rtc_read_time,
	.set_time = isl1208_rtc_set_time,
	.read_alarm = isl1208_rtc_read_alarm,
	/*.set_alarm    = isl1208_rtc_set_alarm, */
};

/* sysfs interface */

static ssize_t
isl1208_sysfs_show_atrim(struct device *dev,
			 struct device_attribute *attr, char *buf)
{
	int atr = isl1208_i2c_get_atr(to_i2c_client(dev));
	if (atr < 0)
		return atr;

	return sprintf(buf, "%d.%.2d pF\n", atr >> 2, (atr & 0x3) * 25);
}

static DEVICE_ATTR(atrim, S_IRUGO, isl1208_sysfs_show_atrim, NULL);

static ssize_t
isl1208_sysfs_show_dtrim(struct device *dev,
			 struct device_attribute *attr, char *buf)
{
	int dtr = isl1208_i2c_get_dtr(to_i2c_client(dev));
	if (dtr < 0)
		return dtr;

	return sprintf(buf, "%d ppm\n", dtr);
}

static DEVICE_ATTR(dtrim, S_IRUGO, isl1208_sysfs_show_dtrim, NULL);

static ssize_t
isl1208_sysfs_show_usr(struct device *dev,
		       struct device_attribute *attr, char *buf)
{
	int usr = isl1208_i2c_get_usr(to_i2c_client(dev));
	if (usr < 0)
		return usr;

	return sprintf(buf, "0x%.4x\n", usr);
}

static ssize_t
isl1208_sysfs_store_usr(struct device *dev,
			struct device_attribute *attr,
			const char *buf, size_t count)
{
	int usr = -1;

	if (buf[0] == '0' && (buf[1] == 'x' || buf[1] == 'X')) {
		if (sscanf(buf, "%x", &usr) != 1)
			return -EINVAL;
	} else {
		if (sscanf(buf, "%d", &usr) != 1)
			return -EINVAL;
	}

	if (usr < 0 || usr > 0xffff)
		return -EINVAL;

	return isl1208_i2c_set_usr(to_i2c_client(dev), usr) ? -EIO : count;
}

static DEVICE_ATTR(usr, S_IRUGO | S_IWUSR, isl1208_sysfs_show_usr,
		   isl1208_sysfs_store_usr);

static int
isl1208_sysfs_register(struct device *dev)
{
	int err;

	err = device_create_file(dev, &dev_attr_atrim);
	if (err)
		return err;

	err = device_create_file(dev, &dev_attr_dtrim);
	if (err) {
		device_remove_file(dev, &dev_attr_atrim);
		return err;
	}

	err = device_create_file(dev, &dev_attr_usr);
	if (err) {
		device_remove_file(dev, &dev_attr_atrim);
		device_remove_file(dev, &dev_attr_dtrim);
	}

	return 0;
}

static int
isl1208_sysfs_unregister(struct device *dev)
{
	device_remove_file(dev, &dev_attr_atrim);
	device_remove_file(dev, &dev_attr_atrim);
	device_remove_file(dev, &dev_attr_usr);

	return 0;
}

static int
isl1208_probe(struct i2c_client *client)
{
	int rc = 0;
	struct rtc_device *rtc;

	if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C))
		return -ENODEV;

	if (isl1208_i2c_validate_client(client) < 0)
		return -ENODEV;

	dev_info(&client->dev,
		 "chip found, driver version " DRV_VERSION "\n");

	rtc = rtc_device_register(isl1208_driver.driver.name,
				  &client->dev, &isl1208_rtc_ops,
				  THIS_MODULE);
	if (IS_ERR(rtc))
		return PTR_ERR(rtc);

	i2c_set_clientdata(client, rtc);

	rc = isl1208_i2c_get_sr(client);
	if (rc < 0) {
		dev_err(&client->dev, "reading status failed\n");
		goto exit_unregister;
	}

	if (rc & ISL1208_REG_SR_RTCF)
		dev_warn(&client->dev, "rtc power failure detected, "
			 "please set clock.\n");

	rc = isl1208_sysfs_register(&client->dev);
	if (rc)
		goto exit_unregister;

	return 0;

exit_unregister:
	rtc_device_unregister(rtc);

	return rc;
}

static int
isl1208_remove(struct i2c_client *client)
{
	struct rtc_device *rtc = i2c_get_clientdata(client);

	isl1208_sysfs_unregister(&client->dev);
	rtc_device_unregister(rtc);

	return 0;
}

static struct i2c_driver isl1208_driver = {
	.driver = {
		   .name = "rtc-isl1208",
		   },
	.probe = isl1208_probe,
	.remove = isl1208_remove,
};

static int __init
isl1208_init(void)
{
	return i2c_add_driver(&isl1208_driver);
}

static void __exit
isl1208_exit(void)
{
	i2c_del_driver(&isl1208_driver);
}

MODULE_AUTHOR("Herbert Valerio Riedel <hvr@gnu.org>");
MODULE_DESCRIPTION("Intersil ISL1208 RTC driver");
MODULE_LICENSE("GPL");
MODULE_VERSION(DRV_VERSION);

module_init(isl1208_init);
module_exit(isl1208_exit);
Commit	Line	Data
7e56a7dc HVR	1	/*
	2	* Intersil ISL1208 rtc class driver
	3	*
	4	* Copyright 2005,2006 Hebert Valerio Riedel <hvr@gnu.org>
	5	*
	6	* This program is free software; you can redistribute it and/or modify it
	7	* under the terms of the GNU General Public License as published by the
	8	* Free Software Foundation; either version 2 of the License, or (at your
	9	* option) any later version.
	10	*
	11	*/
	12
	13	#include <linux/module.h>
	14	#include <linux/i2c.h>
	15	#include <linux/bcd.h>
	16	#include <linux/rtc.h>
	17
9edae7bc	18	#define DRV_VERSION "0.3"
7e56a7dc HVR	19
	20	/* Register map */
	21	/* rtc section */
	22	#define ISL1208_REG_SC 0x00
	23	#define ISL1208_REG_MN 0x01
	24	#define ISL1208_REG_HR 0x02
9edae7bc AZ	25	#define ISL1208_REG_HR_MIL (1<<7) /* 24h/12h mode */
9edae7bc AZ	26	#define ISL1208_REG_HR_PM (1<<5) /* PM/AM bit in 12h mode */
7e56a7dc HVR	27	#define ISL1208_REG_DT 0x03
	28	#define ISL1208_REG_MO 0x04
	29	#define ISL1208_REG_YR 0x05
	30	#define ISL1208_REG_DW 0x06
	31	#define ISL1208_RTC_SECTION_LEN 7
	32
	33	/* control/status section */
	34	#define ISL1208_REG_SR 0x07
9edae7bc AZ	35	#define ISL1208_REG_SR_ARST (1<<7) /* auto reset */
	36	#define ISL1208_REG_SR_XTOSCB (1<<6) /* crystal oscillator */
	37	#define ISL1208_REG_SR_WRTC (1<<4) /* write rtc */
	38	#define ISL1208_REG_SR_ALM (1<<2) /* alarm */
	39	#define ISL1208_REG_SR_BAT (1<<1) /* battery */
	40	#define ISL1208_REG_SR_RTCF (1<<0) /* rtc fail */
7e56a7dc	41	#define ISL1208_REG_INT 0x08
9edae7bc	42	#define ISL1208_REG_09 0x09 /* reserved */
7e56a7dc HVR	43	#define ISL1208_REG_ATR 0x0a
	44	#define ISL1208_REG_DTR 0x0b
	45
	46	/* alarm section */
	47	#define ISL1208_REG_SCA 0x0c
	48	#define ISL1208_REG_MNA 0x0d
	49	#define ISL1208_REG_HRA 0x0e
	50	#define ISL1208_REG_DTA 0x0f
	51	#define ISL1208_REG_MOA 0x10
	52	#define ISL1208_REG_DWA 0x11
	53	#define ISL1208_ALARM_SECTION_LEN 6
	54
	55	/* user section */
	56	#define ISL1208_REG_USR1 0x12
	57	#define ISL1208_REG_USR2 0x13
	58	#define ISL1208_USR_SECTION_LEN 2
	59
9edae7bc	60	static struct i2c_driver isl1208_driver;
7e56a7dc HVR	61
	62	/* block read */
	63	static int
	64	isl1208_i2c_read_regs(struct i2c_client *client, u8 reg, u8 buf[],
9edae7bc	65	unsigned len)
7e56a7dc HVR	66	{
	67	u8 reg_addr[1] = { reg };
	68	struct i2c_msg msgs[2] = {
9edae7bc AZ	69	{client->addr, 0, sizeof(reg_addr), reg_addr}
	70	,
	71	{client->addr, I2C_M_RD, len, buf}
7e56a7dc HVR	72	};
	73	int ret;
	74
7e56a7dc HVR	75	BUG_ON(reg > ISL1208_REG_USR2);
	76	BUG_ON(reg + len > ISL1208_REG_USR2 + 1);
	77
	78	ret = i2c_transfer(client->adapter, msgs, 2);
	79	if (ret > 0)
	80	ret = 0;
	81	return ret;
	82	}
	83
	84	/* block write */
	85	static int
	86	isl1208_i2c_set_regs(struct i2c_client *client, u8 reg, u8 const buf[],
9edae7bc	87	unsigned len)
7e56a7dc HVR	88	{
	89	u8 i2c_buf[ISL1208_REG_USR2 + 2];
	90	struct i2c_msg msgs[1] = {
9edae7bc	91	{client->addr, 0, len + 1, i2c_buf}
7e56a7dc HVR	92	};
	93	int ret;
	94
7e56a7dc HVR	95	BUG_ON(reg > ISL1208_REG_USR2);
	96	BUG_ON(reg + len > ISL1208_REG_USR2 + 1);
	97
	98	i2c_buf[0] = reg;
	99	memcpy(&i2c_buf[1], &buf[0], len);
	100
	101	ret = i2c_transfer(client->adapter, msgs, 1);
	102	if (ret > 0)
	103	ret = 0;
	104	return ret;
	105	}
	106
	107	/* simple check to see wether we have a isl1208 */
9edae7bc AZ	108	static int
9edae7bc AZ	109	isl1208_i2c_validate_client(struct i2c_client *client)
7e56a7dc HVR	110	{
	111	u8 regs[ISL1208_RTC_SECTION_LEN] = { 0, };
	112	u8 zero_mask[ISL1208_RTC_SECTION_LEN] = {
	113	0x80, 0x80, 0x40, 0xc0, 0xe0, 0x00, 0xf8
	114	};
	115	int i;
	116	int ret;
	117
	118	ret = isl1208_i2c_read_regs(client, 0, regs, ISL1208_RTC_SECTION_LEN);
	119	if (ret < 0)
	120	return ret;
	121
	122	for (i = 0; i < ISL1208_RTC_SECTION_LEN; ++i) {
9edae7bc	123	if (regs[i] & zero_mask[i]) /* check if bits are cleared */
7e56a7dc HVR	124	return -ENODEV;
	125	}
	126
	127	return 0;
	128	}
	129
9edae7bc AZ	130	static int
9edae7bc AZ	131	isl1208_i2c_get_sr(struct i2c_client *client)
7e56a7dc	132	{
9edae7bc AZ	133	int sr = i2c_smbus_read_byte_data(client, ISL1208_REG_SR);
	134	if (sr < 0)
	135	return -EIO;
	136
	137	return sr;
7e56a7dc HVR	138	}
7e56a7dc HVR	139
9edae7bc AZ	140	static int
9edae7bc AZ	141	isl1208_i2c_get_atr(struct i2c_client *client)
7e56a7dc HVR	142	{
7e56a7dc HVR	143	int atr = i2c_smbus_read_byte_data(client, ISL1208_REG_ATR);
7e56a7dc	144	if (atr < 0)
9edae7bc	145	return atr;
7e56a7dc HVR	146
	147	/* The 6bit value in the ATR register controls the load
	148	* capacitance C_load * in steps of 0.25pF
	149	*
	150	* bit (1<<5) of the ATR register is inverted
	151	*
	152	* C_load(ATR=0x20) = 4.50pF
	153	* C_load(ATR=0x00) = 12.50pF
	154	* C_load(ATR=0x1f) = 20.25pF
	155	*
	156	*/
	157
9edae7bc AZ	158	atr &= 0x3f; /* mask out lsb */
	159	atr ^= 1 << 5; /* invert 6th bit */
	160	atr += 2 * 9; /* add offset of 4.5pF; unit[atr] = 0.25pF */
7e56a7dc HVR	161
	162	return atr;
	163	}
	164
9edae7bc AZ	165	static int
9edae7bc AZ	166	isl1208_i2c_get_dtr(struct i2c_client *client)
7e56a7dc HVR	167	{
7e56a7dc HVR	168	int dtr = i2c_smbus_read_byte_data(client, ISL1208_REG_DTR);
7e56a7dc HVR	169	if (dtr < 0)
	170	return -EIO;
	171
	172	/* dtr encodes adjustments of {-60,-40,-20,0,20,40,60} ppm */
9edae7bc	173	dtr = ((dtr & 0x3) * 20) * (dtr & (1 << 2) ? -1 : 1);
7e56a7dc HVR	174
	175	return dtr;
	176	}
	177
9edae7bc AZ	178	static int
9edae7bc AZ	179	isl1208_i2c_get_usr(struct i2c_client *client)
7e56a7dc HVR	180	{
	181	u8 buf[ISL1208_USR_SECTION_LEN] = { 0, };
	182	int ret;
	183
9edae7bc AZ	184	ret = isl1208_i2c_read_regs(client, ISL1208_REG_USR1, buf,
9edae7bc AZ	185	ISL1208_USR_SECTION_LEN);
7e56a7dc HVR	186	if (ret < 0)
	187	return ret;
	188
	189	return (buf[1] << 8) \| buf[0];
	190	}
	191
9edae7bc AZ	192	static int
9edae7bc AZ	193	isl1208_i2c_set_usr(struct i2c_client *client, u16 usr)
7e56a7dc HVR	194	{
	195	u8 buf[ISL1208_USR_SECTION_LEN];
	196
	197	buf[0] = usr & 0xff;
	198	buf[1] = (usr >> 8) & 0xff;
	199
9edae7bc AZ	200	return isl1208_i2c_set_regs(client, ISL1208_REG_USR1, buf,
9edae7bc AZ	201	ISL1208_USR_SECTION_LEN);
7e56a7dc HVR	202	}
7e56a7dc HVR	203
9edae7bc AZ	204	static int
9edae7bc AZ	205	isl1208_rtc_proc(struct device dev, struct seq_file seq)
7e56a7dc HVR	206	{
	207	struct i2c_client *const client = to_i2c_client(dev);
	208	int sr, dtr, atr, usr;
	209
	210	sr = isl1208_i2c_get_sr(client);
	211	if (sr < 0) {
	212	dev_err(&client->dev, "%s: reading SR failed\n", __func__);
	213	return sr;
	214	}
	215
	216	seq_printf(seq, "status_reg\t:%s%s%s%s%s%s (0x%.2x)\n",
	217	(sr & ISL1208_REG_SR_RTCF) ? " RTCF" : "",
	218	(sr & ISL1208_REG_SR_BAT) ? " BAT" : "",
	219	(sr & ISL1208_REG_SR_ALM) ? " ALM" : "",
	220	(sr & ISL1208_REG_SR_WRTC) ? " WRTC" : "",
	221	(sr & ISL1208_REG_SR_XTOSCB) ? " XTOSCB" : "",
9edae7bc	222	(sr & ISL1208_REG_SR_ARST) ? " ARST" : "", sr);
7e56a7dc HVR	223
	224	seq_printf(seq, "batt_status\t: %s\n",
	225	(sr & ISL1208_REG_SR_RTCF) ? "bad" : "okay");
	226
	227	dtr = isl1208_i2c_get_dtr(client);
9edae7bc	228	if (dtr >= 0 - 1)
7e56a7dc HVR	229	seq_printf(seq, "digital_trim\t: %d ppm\n", dtr);
	230
	231	atr = isl1208_i2c_get_atr(client);
	232	if (atr >= 0)
	233	seq_printf(seq, "analog_trim\t: %d.%.2d pF\n",
9edae7bc	234	atr >> 2, (atr & 0x3) * 25);
7e56a7dc HVR	235
	236	usr = isl1208_i2c_get_usr(client);
	237	if (usr >= 0)
	238	seq_printf(seq, "user_data\t: 0x%.4x\n", usr);
	239
	240	return 0;
	241	}
	242
9edae7bc AZ	243	static int
9edae7bc AZ	244	isl1208_i2c_read_time(struct i2c_client client, struct rtc_time tm)
7e56a7dc HVR	245	{
	246	int sr;
	247	u8 regs[ISL1208_RTC_SECTION_LEN] = { 0, };
	248
	249	sr = isl1208_i2c_get_sr(client);
	250	if (sr < 0) {
	251	dev_err(&client->dev, "%s: reading SR failed\n", __func__);
	252	return -EIO;
	253	}
	254
	255	sr = isl1208_i2c_read_regs(client, 0, regs, ISL1208_RTC_SECTION_LEN);
	256	if (sr < 0) {
	257	dev_err(&client->dev, "%s: reading RTC section failed\n",
	258	__func__);
	259	return sr;
	260	}
	261
	262	tm->tm_sec = BCD2BIN(regs[ISL1208_REG_SC]);
	263	tm->tm_min = BCD2BIN(regs[ISL1208_REG_MN]);
9edae7bc AZ	264
	265	/* HR field has a more complex interpretation */
	266	{
7e56a7dc	267	const u8 _hr = regs[ISL1208_REG_HR];
9edae7bc	268	if (_hr & ISL1208_REG_HR_MIL) /* 24h format */
7e56a7dc	269	tm->tm_hour = BCD2BIN(_hr & 0x3f);
9edae7bc AZ	270	else {
9edae7bc AZ	271	/* 12h format */
7e56a7dc	272	tm->tm_hour = BCD2BIN(_hr & 0x1f);
9edae7bc	273	if (_hr & ISL1208_REG_HR_PM) /* PM flag set */
7e56a7dc HVR	274	tm->tm_hour += 12;
	275	}
	276	}
	277
	278	tm->tm_mday = BCD2BIN(regs[ISL1208_REG_DT]);
9edae7bc	279	tm->tm_mon = BCD2BIN(regs[ISL1208_REG_MO]) - 1; /* rtc starts at 1 */
7e56a7dc HVR	280	tm->tm_year = BCD2BIN(regs[ISL1208_REG_YR]) + 100;
	281	tm->tm_wday = BCD2BIN(regs[ISL1208_REG_DW]);
	282
	283	return 0;
	284	}
	285
9edae7bc AZ	286	static int
9edae7bc AZ	287	isl1208_i2c_read_alarm(struct i2c_client client, struct rtc_wkalrm alarm)
7e56a7dc HVR	288	{
	289	struct rtc_time *const tm = &alarm->time;
	290	u8 regs[ISL1208_ALARM_SECTION_LEN] = { 0, };
	291	int sr;
	292
	293	sr = isl1208_i2c_get_sr(client);
	294	if (sr < 0) {
	295	dev_err(&client->dev, "%s: reading SR failed\n", __func__);
	296	return sr;
	297	}
	298
	299	sr = isl1208_i2c_read_regs(client, ISL1208_REG_SCA, regs,
9edae7bc	300	ISL1208_ALARM_SECTION_LEN);
7e56a7dc HVR	301	if (sr < 0) {
	302	dev_err(&client->dev, "%s: reading alarm section failed\n",
	303	__func__);
	304	return sr;
	305	}
	306
	307	/* MSB of each alarm register is an enable bit */
9edae7bc AZ	308	tm->tm_sec = BCD2BIN(regs[ISL1208_REG_SCA - ISL1208_REG_SCA] & 0x7f);
	309	tm->tm_min = BCD2BIN(regs[ISL1208_REG_MNA - ISL1208_REG_SCA] & 0x7f);
	310	tm->tm_hour = BCD2BIN(regs[ISL1208_REG_HRA - ISL1208_REG_SCA] & 0x3f);
	311	tm->tm_mday = BCD2BIN(regs[ISL1208_REG_DTA - ISL1208_REG_SCA] & 0x3f);
	312	tm->tm_mon =
	313	BCD2BIN(regs[ISL1208_REG_MOA - ISL1208_REG_SCA] & 0x1f) - 1;
	314	tm->tm_wday = BCD2BIN(regs[ISL1208_REG_DWA - ISL1208_REG_SCA] & 0x03);
7e56a7dc HVR	315
	316	return 0;
	317	}
	318
9edae7bc AZ	319	static int
9edae7bc AZ	320	isl1208_rtc_read_time(struct device dev, struct rtc_time tm)
7e56a7dc HVR	321	{
	322	return isl1208_i2c_read_time(to_i2c_client(dev), tm);
	323	}
	324
9edae7bc AZ	325	static int
9edae7bc AZ	326	isl1208_i2c_set_time(struct i2c_client client, struct rtc_time const tm)
7e56a7dc HVR	327	{
	328	int sr;
	329	u8 regs[ISL1208_RTC_SECTION_LEN] = { 0, };
	330
	331	regs[ISL1208_REG_SC] = BIN2BCD(tm->tm_sec);
	332	regs[ISL1208_REG_MN] = BIN2BCD(tm->tm_min);
	333	regs[ISL1208_REG_HR] = BIN2BCD(tm->tm_hour) \| ISL1208_REG_HR_MIL;
	334
	335	regs[ISL1208_REG_DT] = BIN2BCD(tm->tm_mday);
	336	regs[ISL1208_REG_MO] = BIN2BCD(tm->tm_mon + 1);
	337	regs[ISL1208_REG_YR] = BIN2BCD(tm->tm_year - 100);
	338
	339	regs[ISL1208_REG_DW] = BIN2BCD(tm->tm_wday & 7);
	340
	341	sr = isl1208_i2c_get_sr(client);
	342	if (sr < 0) {
	343	dev_err(&client->dev, "%s: reading SR failed\n", __func__);
	344	return sr;
	345	}
	346
	347	/* set WRTC */
9edae7bc	348	sr = i2c_smbus_write_byte_data(client, ISL1208_REG_SR,
7e56a7dc HVR	349	sr \| ISL1208_REG_SR_WRTC);
	350	if (sr < 0) {
	351	dev_err(&client->dev, "%s: writing SR failed\n", __func__);
	352	return sr;
	353	}
	354
	355	/* write RTC registers */
	356	sr = isl1208_i2c_set_regs(client, 0, regs, ISL1208_RTC_SECTION_LEN);
	357	if (sr < 0) {
	358	dev_err(&client->dev, "%s: writing RTC section failed\n",
	359	__func__);
	360	return sr;
	361	}
	362
	363	/* clear WRTC again */
9edae7bc	364	sr = i2c_smbus_write_byte_data(client, ISL1208_REG_SR,
7e56a7dc HVR	365	sr & ~ISL1208_REG_SR_WRTC);
	366	if (sr < 0) {
	367	dev_err(&client->dev, "%s: writing SR failed\n", __func__);
	368	return sr;
	369	}
	370
	371	return 0;
	372	}
	373
	374
9edae7bc AZ	375	static int
9edae7bc AZ	376	isl1208_rtc_set_time(struct device dev, struct rtc_time tm)
7e56a7dc HVR	377	{
	378	return isl1208_i2c_set_time(to_i2c_client(dev), tm);
	379	}
	380
9edae7bc AZ	381	static int
9edae7bc AZ	382	isl1208_rtc_read_alarm(struct device dev, struct rtc_wkalrm alarm)
7e56a7dc HVR	383	{
	384	return isl1208_i2c_read_alarm(to_i2c_client(dev), alarm);
	385	}
	386
ff8371ac	387	static const struct rtc_class_ops isl1208_rtc_ops = {
9edae7bc AZ	388	.proc = isl1208_rtc_proc,
	389	.read_time = isl1208_rtc_read_time,
	390	.set_time = isl1208_rtc_set_time,
	391	.read_alarm = isl1208_rtc_read_alarm,
	392	/.set_alarm = isl1208_rtc_set_alarm, /
7e56a7dc HVR	393	};
	394
	395	/* sysfs interface */
	396
9edae7bc AZ	397	static ssize_t
	398	isl1208_sysfs_show_atrim(struct device *dev,
	399	struct device_attribute attr, char buf)
7e56a7dc	400	{
9edae7bc	401	int atr = isl1208_i2c_get_atr(to_i2c_client(dev));
7e56a7dc HVR	402	if (atr < 0)
	403	return atr;
	404
9edae7bc	405	return sprintf(buf, "%d.%.2d pF\n", atr >> 2, (atr & 0x3) * 25);
7e56a7dc	406	}
9edae7bc	407
7e56a7dc HVR	408	static DEVICE_ATTR(atrim, S_IRUGO, isl1208_sysfs_show_atrim, NULL);
7e56a7dc HVR	409
9edae7bc AZ	410	static ssize_t
	411	isl1208_sysfs_show_dtrim(struct device *dev,
	412	struct device_attribute attr, char buf)
7e56a7dc	413	{
9edae7bc	414	int dtr = isl1208_i2c_get_dtr(to_i2c_client(dev));
7e56a7dc HVR	415	if (dtr < 0)
	416	return dtr;
	417
	418	return sprintf(buf, "%d ppm\n", dtr);
	419	}
9edae7bc	420
7e56a7dc HVR	421	static DEVICE_ATTR(dtrim, S_IRUGO, isl1208_sysfs_show_dtrim, NULL);
7e56a7dc HVR	422
9edae7bc AZ	423	static ssize_t
	424	isl1208_sysfs_show_usr(struct device *dev,
	425	struct device_attribute attr, char buf)
7e56a7dc	426	{
9edae7bc	427	int usr = isl1208_i2c_get_usr(to_i2c_client(dev));
7e56a7dc HVR	428	if (usr < 0)
	429	return usr;
	430
	431	return sprintf(buf, "0x%.4x\n", usr);
	432	}
	433
9edae7bc AZ	434	static ssize_t
	435	isl1208_sysfs_store_usr(struct device *dev,
	436	struct device_attribute *attr,
	437	const char *buf, size_t count)
7e56a7dc HVR	438	{
	439	int usr = -1;
	440
	441	if (buf[0] == '0' && (buf[1] == 'x' \|\| buf[1] == 'X')) {
	442	if (sscanf(buf, "%x", &usr) != 1)
	443	return -EINVAL;
	444	} else {
	445	if (sscanf(buf, "%d", &usr) != 1)
	446	return -EINVAL;
	447	}
	448
	449	if (usr < 0 \|\| usr > 0xffff)
	450	return -EINVAL;
	451
	452	return isl1208_i2c_set_usr(to_i2c_client(dev), usr) ? -EIO : count;
	453	}
9edae7bc	454
7e56a7dc HVR	455	static DEVICE_ATTR(usr, S_IRUGO \| S_IWUSR, isl1208_sysfs_show_usr,
	456	isl1208_sysfs_store_usr);
	457
	458	static int
9edae7bc	459	isl1208_sysfs_register(struct device *dev)
7e56a7dc	460	{
9edae7bc AZ	461	int err;
	462
	463	err = device_create_file(dev, &dev_attr_atrim);
	464	if (err)
	465	return err;
7e56a7dc	466
9edae7bc AZ	467	err = device_create_file(dev, &dev_attr_dtrim);
	468	if (err) {
	469	device_remove_file(dev, &dev_attr_atrim);
	470	return err;
7e56a7dc HVR	471	}
7e56a7dc HVR	472
9edae7bc AZ	473	err = device_create_file(dev, &dev_attr_usr);
	474	if (err) {
	475	device_remove_file(dev, &dev_attr_atrim);
	476	device_remove_file(dev, &dev_attr_dtrim);
7e56a7dc HVR	477	}
7e56a7dc HVR	478
9edae7bc AZ	479	return 0;
9edae7bc AZ	480	}
7e56a7dc	481
9edae7bc AZ	482	static int
	483	isl1208_sysfs_unregister(struct device *dev)
	484	{
	485	device_remove_file(dev, &dev_attr_atrim);
	486	device_remove_file(dev, &dev_attr_atrim);
	487	device_remove_file(dev, &dev_attr_usr);
	488
	489	return 0;
	490	}
	491
	492	static int
	493	isl1208_probe(struct i2c_client *client)
	494	{
	495	int rc = 0;
	496	struct rtc_device *rtc;
7e56a7dc	497
9edae7bc AZ	498	if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C))
9edae7bc AZ	499	return -ENODEV;
7e56a7dc	500
9edae7bc AZ	501	if (isl1208_i2c_validate_client(client) < 0)
	502	return -ENODEV;
	503
	504	dev_info(&client->dev,
7e56a7dc HVR	505	"chip found, driver version " DRV_VERSION "\n");
	506
	507	rtc = rtc_device_register(isl1208_driver.driver.name,
9edae7bc AZ	508	&client->dev, &isl1208_rtc_ops,
	509	THIS_MODULE);
	510	if (IS_ERR(rtc))
	511	return PTR_ERR(rtc);
7e56a7dc	512
9edae7bc	513	i2c_set_clientdata(client, rtc);
7e56a7dc	514
9edae7bc	515	rc = isl1208_i2c_get_sr(client);
7e56a7dc	516	if (rc < 0) {
9edae7bc AZ	517	dev_err(&client->dev, "reading status failed\n");
9edae7bc AZ	518	goto exit_unregister;
7e56a7dc HVR	519	}
	520
	521	if (rc & ISL1208_REG_SR_RTCF)
9edae7bc	522	dev_warn(&client->dev, "rtc power failure detected, "
7e56a7dc HVR	523	"please set clock.\n");
7e56a7dc HVR	524
9edae7bc AZ	525	rc = isl1208_sysfs_register(&client->dev);
	526	if (rc)
	527	goto exit_unregister;
7e56a7dc HVR	528
	529	return 0;
	530
9edae7bc	531	exit_unregister:
7e56a7dc	532	rtc_device_unregister(rtc);
7e56a7dc	533
9edae7bc	534	return rc;
7e56a7dc HVR	535	}
	536
	537	static int
9edae7bc	538	isl1208_remove(struct i2c_client *client)
7e56a7dc	539	{
9edae7bc	540	struct rtc_device *rtc = i2c_get_clientdata(client);
7e56a7dc	541
9edae7bc AZ	542	isl1208_sysfs_unregister(&client->dev);
9edae7bc AZ	543	rtc_device_unregister(rtc);
7e56a7dc HVR	544
	545	return 0;
	546	}
	547
9edae7bc AZ	548	static struct i2c_driver isl1208_driver = {
	549	.driver = {
	550	.name = "rtc-isl1208",
	551	},
	552	.probe = isl1208_probe,
	553	.remove = isl1208_remove,
	554	};
7e56a7dc	555
9edae7bc AZ	556	static int __init
9edae7bc AZ	557	isl1208_init(void)
7e56a7dc HVR	558	{
	559	return i2c_add_driver(&isl1208_driver);
	560	}
	561
9edae7bc AZ	562	static void __exit
9edae7bc AZ	563	isl1208_exit(void)
7e56a7dc HVR	564	{
	565	i2c_del_driver(&isl1208_driver);
	566	}
	567
	568	MODULE_AUTHOR("Herbert Valerio Riedel <hvr@gnu.org>");
	569	MODULE_DESCRIPTION("Intersil ISL1208 RTC driver");
	570	MODULE_LICENSE("GPL");
	571	MODULE_VERSION(DRV_VERSION);
	572
	573	module_init(isl1208_init);
	574	module_exit(isl1208_exit);