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Commit 7e56a7dc authored by Herbert Valerio Riedel's avatar Herbert Valerio Riedel Committed by Linus Torvalds
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[PATCH] RTC subsystem, Add ISL1208 support 



Add support for the I2C-attached Intersil ISL1208 RTC chip.

[akpm@osdl.org: cleanups, fixlets]
Signed-off-by: default avatarHerbert Valerio Riedel <hvr@gnu.org>
Cc: Alessandro Zummo <a.zummo@towertech.it>
Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
parent bef317e3

drivers/rtc/Kconfig

+10 −0
Original line number Diff line number Diff line
@@ -121,6 +121,16 @@ config RTC_DRV_DS1553 
	  This driver can also be built as a module. If so, the module

	  will be called rtc-ds1553.



config RTC_DRV_ISL1208

	tristate "Intersil 1208"

	depends on RTC_CLASS && I2C

	help

	  If you say yes here you get support for the

	  Intersil 1208 RTC chip.



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

	  will be called rtc-isl1208.



config RTC_DRV_DS1672

	tristate "Dallas/Maxim DS1672"

	depends on RTC_CLASS && I2C

drivers/rtc/Makefile

+1 −0
Original line number Diff line number Diff line
@@ -12,6 +12,7 @@ obj-$(CONFIG_RTC_INTF_PROC) += rtc-proc.o 
obj-$(CONFIG_RTC_INTF_DEV)	+= rtc-dev.o



obj-$(CONFIG_RTC_DRV_X1205)	+= rtc-x1205.o

obj-$(CONFIG_RTC_DRV_ISL1208)	+= rtc-isl1208.o

obj-$(CONFIG_RTC_DRV_TEST)	+= rtc-test.o

obj-$(CONFIG_RTC_DRV_DS1307)	+= rtc-ds1307.o

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

drivers/rtc/rtc-isl1208.c

0 → 100644
+591 −0
Original line number Diff line number Diff line 
/*

 * 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_NAME "isl1208"

#define DRV_VERSION "0.2"



/* 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



/* i2c configuration */

#define ISL1208_I2C_ADDR 0xde



static unsigned short normal_i2c[] = {

	ISL1208_I2C_ADDR>>1, I2C_CLIENT_END

};

I2C_CLIENT_INSMOD; /* defines addr_data */



static int isl1208_attach_adapter(struct i2c_adapter *adapter);

static int isl1208_detach_client(struct i2c_client *client);



static struct i2c_driver isl1208_driver = {

	.driver		= {

		.name	= DRV_NAME,

	},

	.id		= I2C_DRIVERID_ISL1208,

	.attach_adapter = &isl1208_attach_adapter,

	.detach_client	= &isl1208_detach_client,

};



/* 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, client->flags, sizeof(reg_addr), reg_addr },

		{ client->addr, client->flags | I2C_M_RD, len, buf }

	};

	int ret;



	BUG_ON(len == 0);

	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, client->flags, len + 1, i2c_buf }

	};

	int ret;



	BUG_ON(len == 0);

	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)

{

	return i2c_smbus_read_byte_data(client, ISL1208_REG_SR) == -1 ? -EIO:0;

}



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 -EIO;



	/* 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 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;



	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;



	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;



	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_probe(struct i2c_adapter *adapter, int addr, int kind)

{

	int rc = 0;

	struct i2c_client *new_client = NULL;

	struct rtc_device *rtc = NULL;



	if (!i2c_check_functionality(adapter, I2C_FUNC_I2C)) {

		rc = -ENODEV;

		goto failout;

	}



	new_client = kzalloc(sizeof(struct i2c_client), GFP_KERNEL);

	if (new_client == NULL) {

		rc = -ENOMEM;

		goto failout;

	}



	new_client->addr = addr;

	new_client->adapter = adapter;

	new_client->driver = &isl1208_driver;

	new_client->flags = 0;

	strcpy(new_client->name, DRV_NAME);



	if (kind < 0) {

		rc = isl1208_i2c_validate_client(new_client);

		if (rc < 0)

			goto failout;

	}



	rc = i2c_attach_client(new_client);

	if (rc < 0)

		goto failout;



	dev_info(&new_client->dev,

		 "chip found, driver version " DRV_VERSION "\n");



	rtc = rtc_device_register(isl1208_driver.driver.name,

				  &new_client->dev,

				  &isl1208_rtc_ops, THIS_MODULE);



	if (IS_ERR(rtc)) {

		rc = PTR_ERR(rtc);

		goto failout_detach;

	}



	i2c_set_clientdata(new_client, rtc);



	rc = isl1208_i2c_get_sr(new_client);

	if (rc < 0) {

		dev_err(&new_client->dev, "reading status failed\n");

		goto failout_unregister;

	}



	if (rc & ISL1208_REG_SR_RTCF)

		dev_warn(&new_client->dev, "rtc power failure detected, "

			 "please set clock.\n");



	rc = device_create_file(&new_client->dev, &dev_attr_atrim);

	if (rc < 0)

		goto failout_unregister;

	rc = device_create_file(&new_client->dev, &dev_attr_dtrim);

	if (rc < 0)

		goto failout_atrim;

	rc = device_create_file(&new_client->dev, &dev_attr_usr);

	if (rc < 0)

		goto failout_dtrim;



	return 0;



 failout_dtrim:

	device_remove_file(&new_client->dev, &dev_attr_dtrim);

 failout_atrim:

	device_remove_file(&new_client->dev, &dev_attr_atrim);

 failout_unregister:

	rtc_device_unregister(rtc);

 failout_detach:

	i2c_detach_client(new_client);

 failout:

	kfree(new_client);

	return rc;

}



static int

isl1208_attach_adapter (struct i2c_adapter *adapter)

{

	return i2c_probe(adapter, &addr_data, isl1208_probe);

}



static int

isl1208_detach_client(struct i2c_client *client)

{

	int rc;

	struct rtc_device *const rtc = i2c_get_clientdata(client);



	if (rtc)

		rtc_device_unregister(rtc); /* do we need to kfree? */



	rc = i2c_detach_client(client);

	if (rc)

		return rc;



	kfree(client);



	return 0;

}



/* module management */



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);

include/linux/i2c-id.h

+1 −0
Original line number Diff line number Diff line
@@ -115,6 +115,7 @@ 
#define I2C_DRIVERID_BT866	85	/* Conexant bt866 video encoder */

#define I2C_DRIVERID_KS0127	86	/* Samsung ks0127 video decoder */

#define I2C_DRIVERID_TLV320AIC23B 87	/* TI TLV320AIC23B audio codec  */

#define I2C_DRIVERID_ISL1208	88	/* Intersil ISL1208 RTC		*/



#define I2C_DRIVERID_I2CDEV	900

#define I2C_DRIVERID_ARP        902    /* SMBus ARP Client              */