272 строки
7.3 KiB
C
272 строки
7.3 KiB
C
/*
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* An I2C driver for the Philips PCF8563 RTC
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* Copyright 2005-06 Tower Technologies
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*
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* Author: Alessandro Zummo <a.zummo@towertech.it>
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* Maintainers: http://www.nslu2-linux.org/
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*
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* based on the other drivers in this same directory.
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*
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* http://www.semiconductors.philips.com/acrobat/datasheets/PCF8563-04.pdf
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License version 2 as
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* published by the Free Software Foundation.
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*/
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#include <linux/i2c.h>
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#include <linux/bcd.h>
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#include <linux/rtc.h>
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#include <linux/slab.h>
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#include <linux/module.h>
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#define DRV_VERSION "0.4.3"
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#define PCF8563_REG_ST1 0x00 /* status */
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#define PCF8563_REG_ST2 0x01
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#define PCF8563_REG_SC 0x02 /* datetime */
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#define PCF8563_REG_MN 0x03
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#define PCF8563_REG_HR 0x04
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#define PCF8563_REG_DM 0x05
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#define PCF8563_REG_DW 0x06
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#define PCF8563_REG_MO 0x07
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#define PCF8563_REG_YR 0x08
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#define PCF8563_REG_AMN 0x09 /* alarm */
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#define PCF8563_REG_AHR 0x0A
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#define PCF8563_REG_ADM 0x0B
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#define PCF8563_REG_ADW 0x0C
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#define PCF8563_REG_CLKO 0x0D /* clock out */
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#define PCF8563_REG_TMRC 0x0E /* timer control */
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#define PCF8563_REG_TMR 0x0F /* timer */
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#define PCF8563_SC_LV 0x80 /* low voltage */
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#define PCF8563_MO_C 0x80 /* century */
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static struct i2c_driver pcf8563_driver;
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struct pcf8563 {
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struct rtc_device *rtc;
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/*
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* The meaning of MO_C bit varies by the chip type.
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* From PCF8563 datasheet: this bit is toggled when the years
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* register overflows from 99 to 00
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* 0 indicates the century is 20xx
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* 1 indicates the century is 19xx
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* From RTC8564 datasheet: this bit indicates change of
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* century. When the year digit data overflows from 99 to 00,
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* this bit is set. By presetting it to 0 while still in the
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* 20th century, it will be set in year 2000, ...
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* There seems no reliable way to know how the system use this
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* bit. So let's do it heuristically, assuming we are live in
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* 1970...2069.
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*/
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int c_polarity; /* 0: MO_C=1 means 19xx, otherwise MO_C=1 means 20xx */
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};
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/*
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* In the routines that deal directly with the pcf8563 hardware, we use
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* rtc_time -- month 0-11, hour 0-23, yr = calendar year-epoch.
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*/
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static int pcf8563_get_datetime(struct i2c_client *client, struct rtc_time *tm)
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{
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struct pcf8563 *pcf8563 = i2c_get_clientdata(client);
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unsigned char buf[13] = { PCF8563_REG_ST1 };
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struct i2c_msg msgs[] = {
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{ client->addr, 0, 1, buf }, /* setup read ptr */
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{ client->addr, I2C_M_RD, 13, buf }, /* read status + date */
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};
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/* read registers */
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if ((i2c_transfer(client->adapter, msgs, 2)) != 2) {
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dev_err(&client->dev, "%s: read error\n", __func__);
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return -EIO;
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}
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if (buf[PCF8563_REG_SC] & PCF8563_SC_LV)
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dev_info(&client->dev,
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"low voltage detected, date/time is not reliable.\n");
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dev_dbg(&client->dev,
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"%s: raw data is st1=%02x, st2=%02x, sec=%02x, min=%02x, hr=%02x, "
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"mday=%02x, wday=%02x, mon=%02x, year=%02x\n",
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__func__,
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buf[0], buf[1], buf[2], buf[3],
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buf[4], buf[5], buf[6], buf[7],
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buf[8]);
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tm->tm_sec = bcd2bin(buf[PCF8563_REG_SC] & 0x7F);
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tm->tm_min = bcd2bin(buf[PCF8563_REG_MN] & 0x7F);
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tm->tm_hour = bcd2bin(buf[PCF8563_REG_HR] & 0x3F); /* rtc hr 0-23 */
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tm->tm_mday = bcd2bin(buf[PCF8563_REG_DM] & 0x3F);
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tm->tm_wday = buf[PCF8563_REG_DW] & 0x07;
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tm->tm_mon = bcd2bin(buf[PCF8563_REG_MO] & 0x1F) - 1; /* rtc mn 1-12 */
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tm->tm_year = bcd2bin(buf[PCF8563_REG_YR]);
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if (tm->tm_year < 70)
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tm->tm_year += 100; /* assume we are in 1970...2069 */
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/* detect the polarity heuristically. see note above. */
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pcf8563->c_polarity = (buf[PCF8563_REG_MO] & PCF8563_MO_C) ?
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(tm->tm_year >= 100) : (tm->tm_year < 100);
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dev_dbg(&client->dev, "%s: tm is secs=%d, mins=%d, hours=%d, "
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"mday=%d, mon=%d, year=%d, wday=%d\n",
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__func__,
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tm->tm_sec, tm->tm_min, tm->tm_hour,
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tm->tm_mday, tm->tm_mon, tm->tm_year, tm->tm_wday);
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/* the clock can give out invalid datetime, but we cannot return
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* -EINVAL otherwise hwclock will refuse to set the time on bootup.
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*/
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if (rtc_valid_tm(tm) < 0)
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dev_err(&client->dev, "retrieved date/time is not valid.\n");
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return 0;
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}
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static int pcf8563_set_datetime(struct i2c_client *client, struct rtc_time *tm)
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{
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struct pcf8563 *pcf8563 = i2c_get_clientdata(client);
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int i, err;
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unsigned char buf[9];
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dev_dbg(&client->dev, "%s: secs=%d, mins=%d, hours=%d, "
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"mday=%d, mon=%d, year=%d, wday=%d\n",
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__func__,
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tm->tm_sec, tm->tm_min, tm->tm_hour,
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tm->tm_mday, tm->tm_mon, tm->tm_year, tm->tm_wday);
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/* hours, minutes and seconds */
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buf[PCF8563_REG_SC] = bin2bcd(tm->tm_sec);
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buf[PCF8563_REG_MN] = bin2bcd(tm->tm_min);
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buf[PCF8563_REG_HR] = bin2bcd(tm->tm_hour);
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buf[PCF8563_REG_DM] = bin2bcd(tm->tm_mday);
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/* month, 1 - 12 */
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buf[PCF8563_REG_MO] = bin2bcd(tm->tm_mon + 1);
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/* year and century */
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buf[PCF8563_REG_YR] = bin2bcd(tm->tm_year % 100);
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if (pcf8563->c_polarity ? (tm->tm_year >= 100) : (tm->tm_year < 100))
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buf[PCF8563_REG_MO] |= PCF8563_MO_C;
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buf[PCF8563_REG_DW] = tm->tm_wday & 0x07;
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/* write register's data */
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for (i = 0; i < 7; i++) {
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unsigned char data[2] = { PCF8563_REG_SC + i,
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buf[PCF8563_REG_SC + i] };
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err = i2c_master_send(client, data, sizeof(data));
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if (err != sizeof(data)) {
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dev_err(&client->dev,
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"%s: err=%d addr=%02x, data=%02x\n",
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__func__, err, data[0], data[1]);
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return -EIO;
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}
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};
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return 0;
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}
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static int pcf8563_rtc_read_time(struct device *dev, struct rtc_time *tm)
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{
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return pcf8563_get_datetime(to_i2c_client(dev), tm);
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}
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static int pcf8563_rtc_set_time(struct device *dev, struct rtc_time *tm)
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{
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return pcf8563_set_datetime(to_i2c_client(dev), tm);
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}
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static const struct rtc_class_ops pcf8563_rtc_ops = {
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.read_time = pcf8563_rtc_read_time,
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.set_time = pcf8563_rtc_set_time,
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};
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static int pcf8563_probe(struct i2c_client *client,
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const struct i2c_device_id *id)
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{
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struct pcf8563 *pcf8563;
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int err = 0;
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dev_dbg(&client->dev, "%s\n", __func__);
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if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C))
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return -ENODEV;
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pcf8563 = kzalloc(sizeof(struct pcf8563), GFP_KERNEL);
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if (!pcf8563)
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return -ENOMEM;
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dev_info(&client->dev, "chip found, driver version " DRV_VERSION "\n");
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i2c_set_clientdata(client, pcf8563);
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pcf8563->rtc = rtc_device_register(pcf8563_driver.driver.name,
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&client->dev, &pcf8563_rtc_ops, THIS_MODULE);
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if (IS_ERR(pcf8563->rtc)) {
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err = PTR_ERR(pcf8563->rtc);
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goto exit_kfree;
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}
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return 0;
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exit_kfree:
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kfree(pcf8563);
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return err;
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}
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static int pcf8563_remove(struct i2c_client *client)
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{
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struct pcf8563 *pcf8563 = i2c_get_clientdata(client);
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if (pcf8563->rtc)
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rtc_device_unregister(pcf8563->rtc);
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kfree(pcf8563);
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return 0;
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}
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static const struct i2c_device_id pcf8563_id[] = {
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{ "pcf8563", 0 },
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{ "rtc8564", 0 },
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{ }
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};
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MODULE_DEVICE_TABLE(i2c, pcf8563_id);
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static struct i2c_driver pcf8563_driver = {
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.driver = {
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.name = "rtc-pcf8563",
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},
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.probe = pcf8563_probe,
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.remove = pcf8563_remove,
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.id_table = pcf8563_id,
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};
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static int __init pcf8563_init(void)
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{
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return i2c_add_driver(&pcf8563_driver);
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}
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static void __exit pcf8563_exit(void)
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{
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i2c_del_driver(&pcf8563_driver);
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}
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MODULE_AUTHOR("Alessandro Zummo <a.zummo@towertech.it>");
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MODULE_DESCRIPTION("Philips PCF8563/Epson RTC8564 RTC driver");
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MODULE_LICENSE("GPL");
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MODULE_VERSION(DRV_VERSION);
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module_init(pcf8563_init);
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module_exit(pcf8563_exit);
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