499 lines
13 KiB
C
499 lines
13 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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#include <linux/of.h>
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#include <linux/err.h>
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#define DRV_VERSION "0.4.4"
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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_BIT_AIE (1 << 1)
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#define PCF8563_BIT_AF (1 << 3)
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#define PCF8563_BITS_ST2_N (7 << 5)
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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_CLKO 0x0D /* clock out */
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#define PCF8563_REG_TMRC 0x0E /* timer control */
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#define PCF8563_TMRC_ENABLE BIT(7)
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#define PCF8563_TMRC_4096 0
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#define PCF8563_TMRC_64 1
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#define PCF8563_TMRC_1 2
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#define PCF8563_TMRC_1_60 3
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#define PCF8563_TMRC_MASK 3
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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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int voltage_low; /* incicates if a low_voltage was detected */
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struct i2c_client *client;
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};
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static int pcf8563_read_block_data(struct i2c_client *client, unsigned char reg,
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unsigned char length, unsigned char *buf)
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{
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struct i2c_msg msgs[] = {
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{/* setup read ptr */
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.addr = client->addr,
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.len = 1,
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.buf = ®,
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},
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{
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.addr = client->addr,
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.flags = I2C_M_RD,
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.len = length,
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.buf = buf
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},
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};
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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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return 0;
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}
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static int pcf8563_write_block_data(struct i2c_client *client,
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unsigned char reg, unsigned char length,
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unsigned char *buf)
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{
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int i, err;
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for (i = 0; i < length; i++) {
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unsigned char data[2] = { reg + i, buf[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_set_alarm_mode(struct i2c_client *client, bool on)
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{
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unsigned char buf;
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int err;
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err = pcf8563_read_block_data(client, PCF8563_REG_ST2, 1, &buf);
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if (err < 0)
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return err;
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if (on)
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buf |= PCF8563_BIT_AIE;
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else
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buf &= ~PCF8563_BIT_AIE;
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buf &= ~(PCF8563_BIT_AF | PCF8563_BITS_ST2_N);
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err = pcf8563_write_block_data(client, PCF8563_REG_ST2, 1, &buf);
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if (err < 0) {
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dev_err(&client->dev, "%s: write error\n", __func__);
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return -EIO;
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}
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return 0;
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}
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static int pcf8563_get_alarm_mode(struct i2c_client *client, unsigned char *en,
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unsigned char *pen)
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{
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unsigned char buf;
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int err;
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err = pcf8563_read_block_data(client, PCF8563_REG_ST2, 1, &buf);
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if (err)
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return err;
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if (en)
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*en = !!(buf & PCF8563_BIT_AIE);
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if (pen)
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*pen = !!(buf & PCF8563_BIT_AF);
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return 0;
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}
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static irqreturn_t pcf8563_irq(int irq, void *dev_id)
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{
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struct pcf8563 *pcf8563 = i2c_get_clientdata(dev_id);
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int err;
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char pending;
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err = pcf8563_get_alarm_mode(pcf8563->client, NULL, &pending);
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if (err)
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return IRQ_NONE;
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if (pending) {
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rtc_update_irq(pcf8563->rtc, 1, RTC_IRQF | RTC_AF);
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pcf8563_set_alarm_mode(pcf8563->client, 1);
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return IRQ_HANDLED;
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}
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return IRQ_NONE;
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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[9];
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int err;
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err = pcf8563_read_block_data(client, PCF8563_REG_ST1, 9, buf);
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if (err)
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return err;
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if (buf[PCF8563_REG_SC] & PCF8563_SC_LV) {
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pcf8563->voltage_low = 1;
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dev_err(&client->dev,
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"low voltage detected, date/time is not reliable.\n");
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return -EINVAL;
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}
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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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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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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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return pcf8563_write_block_data(client, PCF8563_REG_SC,
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9 - PCF8563_REG_SC, buf + PCF8563_REG_SC);
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}
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#ifdef CONFIG_RTC_INTF_DEV
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static int pcf8563_rtc_ioctl(struct device *dev, unsigned int cmd, unsigned long arg)
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{
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struct pcf8563 *pcf8563 = i2c_get_clientdata(to_i2c_client(dev));
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struct rtc_time tm;
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switch (cmd) {
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case RTC_VL_READ:
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if (pcf8563->voltage_low)
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dev_info(dev, "low voltage detected, date/time is not reliable.\n");
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if (copy_to_user((void __user *)arg, &pcf8563->voltage_low,
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sizeof(int)))
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return -EFAULT;
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return 0;
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case RTC_VL_CLR:
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/*
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* Clear the VL bit in the seconds register in case
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* the time has not been set already (which would
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* have cleared it). This does not really matter
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* because of the cached voltage_low value but do it
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* anyway for consistency.
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*/
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if (pcf8563_get_datetime(to_i2c_client(dev), &tm))
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pcf8563_set_datetime(to_i2c_client(dev), &tm);
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/* Clear the cached value. */
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pcf8563->voltage_low = 0;
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return 0;
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default:
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return -ENOIOCTLCMD;
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}
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}
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#else
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#define pcf8563_rtc_ioctl NULL
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#endif
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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 int pcf8563_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *tm)
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{
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struct i2c_client *client = to_i2c_client(dev);
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unsigned char buf[4];
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int err;
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err = pcf8563_read_block_data(client, PCF8563_REG_AMN, 4, buf);
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if (err)
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return err;
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dev_dbg(&client->dev,
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"%s: raw data is min=%02x, hr=%02x, mday=%02x, wday=%02x\n",
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__func__, buf[0], buf[1], buf[2], buf[3]);
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tm->time.tm_min = bcd2bin(buf[0] & 0x7F);
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tm->time.tm_hour = bcd2bin(buf[1] & 0x3F);
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tm->time.tm_mday = bcd2bin(buf[2] & 0x3F);
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tm->time.tm_wday = bcd2bin(buf[3] & 0x7);
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tm->time.tm_mon = -1;
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tm->time.tm_year = -1;
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tm->time.tm_yday = -1;
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tm->time.tm_isdst = -1;
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err = pcf8563_get_alarm_mode(client, &tm->enabled, &tm->pending);
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if (err < 0)
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return err;
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dev_dbg(&client->dev, "%s: tm is mins=%d, hours=%d, mday=%d, wday=%d,"
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" enabled=%d, pending=%d\n", __func__, tm->time.tm_min,
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tm->time.tm_hour, tm->time.tm_mday, tm->time.tm_wday,
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tm->enabled, tm->pending);
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return 0;
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}
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static int pcf8563_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *tm)
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{
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struct i2c_client *client = to_i2c_client(dev);
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unsigned char buf[4];
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int err;
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/* The alarm has no seconds, round up to nearest minute */
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if (tm->time.tm_sec) {
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time64_t alarm_time = rtc_tm_to_time64(&tm->time);
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alarm_time += 60 - tm->time.tm_sec;
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rtc_time64_to_tm(alarm_time, &tm->time);
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}
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dev_dbg(dev, "%s, min=%d hour=%d wday=%d mday=%d "
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"enabled=%d pending=%d\n", __func__,
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tm->time.tm_min, tm->time.tm_hour, tm->time.tm_wday,
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tm->time.tm_mday, tm->enabled, tm->pending);
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buf[0] = bin2bcd(tm->time.tm_min);
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buf[1] = bin2bcd(tm->time.tm_hour);
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buf[2] = bin2bcd(tm->time.tm_mday);
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buf[3] = tm->time.tm_wday & 0x07;
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err = pcf8563_write_block_data(client, PCF8563_REG_AMN, 4, buf);
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if (err)
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return err;
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return pcf8563_set_alarm_mode(client, 1);
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}
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static int pcf8563_irq_enable(struct device *dev, unsigned int enabled)
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{
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dev_dbg(dev, "%s: en=%d\n", __func__, enabled);
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return pcf8563_set_alarm_mode(to_i2c_client(dev), !!enabled);
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}
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static const struct rtc_class_ops pcf8563_rtc_ops = {
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.ioctl = pcf8563_rtc_ioctl,
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.read_time = pcf8563_rtc_read_time,
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.set_time = pcf8563_rtc_set_time,
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.read_alarm = pcf8563_rtc_read_alarm,
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.set_alarm = pcf8563_rtc_set_alarm,
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.alarm_irq_enable = pcf8563_irq_enable,
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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;
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unsigned char buf;
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unsigned char alm_pending;
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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 = devm_kzalloc(&client->dev, sizeof(struct pcf8563),
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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->client = client;
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device_set_wakeup_capable(&client->dev, 1);
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/* Set timer to lowest frequency to save power (ref Haoyu datasheet) */
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buf = PCF8563_TMRC_1_60;
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err = pcf8563_write_block_data(client, PCF8563_REG_TMRC, 1, &buf);
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if (err < 0) {
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dev_err(&client->dev, "%s: write error\n", __func__);
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return err;
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}
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err = pcf8563_get_alarm_mode(client, NULL, &alm_pending);
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if (err) {
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dev_err(&client->dev, "%s: read error\n", __func__);
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return err;
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}
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if (alm_pending)
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pcf8563_set_alarm_mode(client, 0);
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pcf8563->rtc = devm_rtc_device_register(&client->dev,
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pcf8563_driver.driver.name,
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&pcf8563_rtc_ops, THIS_MODULE);
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if (IS_ERR(pcf8563->rtc))
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return PTR_ERR(pcf8563->rtc);
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if (client->irq > 0) {
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err = devm_request_threaded_irq(&client->dev, client->irq,
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NULL, pcf8563_irq,
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IRQF_SHARED|IRQF_ONESHOT|IRQF_TRIGGER_FALLING,
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pcf8563->rtc->name, client);
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if (err) {
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dev_err(&client->dev, "unable to request IRQ %d\n",
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client->irq);
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return err;
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}
|
|
|
|
}
|
|
|
|
/* the pcf8563 alarm only supports a minute accuracy */
|
|
pcf8563->rtc->uie_unsupported = 1;
|
|
|
|
return 0;
|
|
}
|
|
|
|
static const struct i2c_device_id pcf8563_id[] = {
|
|
{ "pcf8563", 0 },
|
|
{ "rtc8564", 0 },
|
|
{ }
|
|
};
|
|
MODULE_DEVICE_TABLE(i2c, pcf8563_id);
|
|
|
|
#ifdef CONFIG_OF
|
|
static const struct of_device_id pcf8563_of_match[] = {
|
|
{ .compatible = "nxp,pcf8563" },
|
|
{}
|
|
};
|
|
MODULE_DEVICE_TABLE(of, pcf8563_of_match);
|
|
#endif
|
|
|
|
static struct i2c_driver pcf8563_driver = {
|
|
.driver = {
|
|
.name = "rtc-pcf8563",
|
|
.owner = THIS_MODULE,
|
|
.of_match_table = of_match_ptr(pcf8563_of_match),
|
|
},
|
|
.probe = pcf8563_probe,
|
|
.id_table = pcf8563_id,
|
|
};
|
|
|
|
module_i2c_driver(pcf8563_driver);
|
|
|
|
MODULE_AUTHOR("Alessandro Zummo <a.zummo@towertech.it>");
|
|
MODULE_DESCRIPTION("Philips PCF8563/Epson RTC8564 RTC driver");
|
|
MODULE_LICENSE("GPL");
|
|
MODULE_VERSION(DRV_VERSION);
|