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![Javier Martinez Canillas](/assets/img/avatar_default.png)
The I2C core always reports the MODALIAS uevent as "i2c:<client name" regardless if the driver was matched using the I2C id_table or the of_match_table. So technically there's no need for a driver to export the OF table since currently it's not used. In fact, the I2C device ID table is mandatory for I2C drivers since a i2c_device_id is passed to the driver's probe function even if the I2C core used the OF table to match the driver. And since the I2C core uses different tables, OF-only drivers needs to have duplicated data that has to be kept in sync and also the dev node compatible manufacturer prefix is stripped when reporting the MODALIAS. To avoid the above, the I2C core behavior may be changed in the future to not require an I2C device table for OF-only drivers and report the OF module alias. So, it's better to also export the OF table to prevent breaking module autoloading if that happens. Signed-off-by: Javier Martinez Canillas <javier@osg.samsung.com> Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
302 lines
7.2 KiB
C
302 lines
7.2 KiB
C
/*
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* An I2C driver for the Intersil ISL 12022
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*
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* Author: Roman Fietze <roman.fietze@telemotive.de>
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*
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* Based on the Philips PCF8563 RTC
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* by Alessandro Zummo <a.zummo@towertech.it>.
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License version
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* 2 as 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/err.h>
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#include <linux/of.h>
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#include <linux/of_device.h>
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#define DRV_VERSION "0.1"
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/* ISL register offsets */
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#define ISL12022_REG_SC 0x00
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#define ISL12022_REG_MN 0x01
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#define ISL12022_REG_HR 0x02
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#define ISL12022_REG_DT 0x03
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#define ISL12022_REG_MO 0x04
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#define ISL12022_REG_YR 0x05
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#define ISL12022_REG_DW 0x06
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#define ISL12022_REG_SR 0x07
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#define ISL12022_REG_INT 0x08
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/* ISL register bits */
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#define ISL12022_HR_MIL (1 << 7) /* military or 24 hour time */
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#define ISL12022_SR_LBAT85 (1 << 2)
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#define ISL12022_SR_LBAT75 (1 << 1)
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#define ISL12022_INT_WRTC (1 << 6)
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static struct i2c_driver isl12022_driver;
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struct isl12022 {
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struct rtc_device *rtc;
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bool write_enabled; /* true if write enable is set */
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};
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static int isl12022_read_regs(struct i2c_client *client, uint8_t reg,
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uint8_t *data, size_t n)
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{
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struct i2c_msg msgs[] = {
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{
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.addr = client->addr,
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.flags = 0,
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.len = 1,
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.buf = data
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}, /* setup read ptr */
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{
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.addr = client->addr,
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.flags = I2C_M_RD,
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.len = n,
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.buf = data
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}
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};
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int ret;
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data[0] = reg;
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ret = i2c_transfer(client->adapter, msgs, ARRAY_SIZE(msgs));
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if (ret != ARRAY_SIZE(msgs)) {
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dev_err(&client->dev, "%s: read error, ret=%d\n",
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__func__, ret);
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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 isl12022_write_reg(struct i2c_client *client,
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uint8_t reg, uint8_t val)
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{
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uint8_t data[2] = { reg, val };
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int err;
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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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return 0;
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}
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/*
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* In the routines that deal directly with the isl12022 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 isl12022_get_datetime(struct i2c_client *client, struct rtc_time *tm)
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{
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uint8_t buf[ISL12022_REG_INT + 1];
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int ret;
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ret = isl12022_read_regs(client, ISL12022_REG_SC, buf, sizeof(buf));
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if (ret)
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return ret;
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if (buf[ISL12022_REG_SR] & (ISL12022_SR_LBAT85 | ISL12022_SR_LBAT75)) {
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dev_warn(&client->dev,
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"voltage dropped below %u%%, "
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"date and time is not reliable.\n",
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buf[ISL12022_REG_SR] & ISL12022_SR_LBAT85 ? 85 : 75);
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}
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dev_dbg(&client->dev,
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"%s: raw data is sec=%02x, min=%02x, hr=%02x, "
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"mday=%02x, mon=%02x, year=%02x, wday=%02x, "
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"sr=%02x, int=%02x",
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__func__,
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buf[ISL12022_REG_SC],
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buf[ISL12022_REG_MN],
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buf[ISL12022_REG_HR],
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buf[ISL12022_REG_DT],
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buf[ISL12022_REG_MO],
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buf[ISL12022_REG_YR],
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buf[ISL12022_REG_DW],
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buf[ISL12022_REG_SR],
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buf[ISL12022_REG_INT]);
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tm->tm_sec = bcd2bin(buf[ISL12022_REG_SC] & 0x7F);
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tm->tm_min = bcd2bin(buf[ISL12022_REG_MN] & 0x7F);
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tm->tm_hour = bcd2bin(buf[ISL12022_REG_HR] & 0x3F);
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tm->tm_mday = bcd2bin(buf[ISL12022_REG_DT] & 0x3F);
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tm->tm_wday = buf[ISL12022_REG_DW] & 0x07;
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tm->tm_mon = bcd2bin(buf[ISL12022_REG_MO] & 0x1F) - 1;
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tm->tm_year = bcd2bin(buf[ISL12022_REG_YR]) + 100;
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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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return rtc_valid_tm(tm);
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}
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static int isl12022_set_datetime(struct i2c_client *client, struct rtc_time *tm)
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{
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struct isl12022 *isl12022 = i2c_get_clientdata(client);
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size_t i;
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int ret;
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uint8_t buf[ISL12022_REG_DW + 1];
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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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if (!isl12022->write_enabled) {
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ret = isl12022_read_regs(client, ISL12022_REG_INT, buf, 1);
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if (ret)
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return ret;
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/* Check if WRTC (write rtc enable) is set factory default is
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* 0 (not set) */
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if (!(buf[0] & ISL12022_INT_WRTC)) {
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dev_info(&client->dev,
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"init write enable and 24 hour format\n");
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/* Set the write enable bit. */
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ret = isl12022_write_reg(client,
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ISL12022_REG_INT,
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buf[0] | ISL12022_INT_WRTC);
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if (ret)
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return ret;
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/* Write to any RTC register to start RTC, we use the
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* HR register, setting the MIL bit to use the 24 hour
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* format. */
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ret = isl12022_read_regs(client, ISL12022_REG_HR,
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buf, 1);
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if (ret)
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return ret;
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ret = isl12022_write_reg(client,
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ISL12022_REG_HR,
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buf[0] | ISL12022_HR_MIL);
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if (ret)
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return ret;
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}
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isl12022->write_enabled = 1;
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}
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/* hours, minutes and seconds */
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buf[ISL12022_REG_SC] = bin2bcd(tm->tm_sec);
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buf[ISL12022_REG_MN] = bin2bcd(tm->tm_min);
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buf[ISL12022_REG_HR] = bin2bcd(tm->tm_hour) | ISL12022_HR_MIL;
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buf[ISL12022_REG_DT] = bin2bcd(tm->tm_mday);
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/* month, 1 - 12 */
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buf[ISL12022_REG_MO] = bin2bcd(tm->tm_mon + 1);
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/* year and century */
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buf[ISL12022_REG_YR] = bin2bcd(tm->tm_year % 100);
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buf[ISL12022_REG_DW] = tm->tm_wday & 0x07;
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/* write register's data */
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for (i = 0; i < ARRAY_SIZE(buf); i++) {
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ret = isl12022_write_reg(client, ISL12022_REG_SC + i,
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buf[ISL12022_REG_SC + i]);
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if (ret)
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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 isl12022_rtc_read_time(struct device *dev, struct rtc_time *tm)
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{
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return isl12022_get_datetime(to_i2c_client(dev), tm);
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}
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static int isl12022_rtc_set_time(struct device *dev, struct rtc_time *tm)
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{
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return isl12022_set_datetime(to_i2c_client(dev), tm);
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}
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static const struct rtc_class_ops isl12022_rtc_ops = {
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.read_time = isl12022_rtc_read_time,
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.set_time = isl12022_rtc_set_time,
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};
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static int isl12022_probe(struct i2c_client *client,
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const struct i2c_device_id *id)
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{
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struct isl12022 *isl12022;
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if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C))
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return -ENODEV;
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isl12022 = devm_kzalloc(&client->dev, sizeof(struct isl12022),
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GFP_KERNEL);
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if (!isl12022)
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return -ENOMEM;
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dev_dbg(&client->dev, "chip found, driver version " DRV_VERSION "\n");
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i2c_set_clientdata(client, isl12022);
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isl12022->rtc = devm_rtc_device_register(&client->dev,
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isl12022_driver.driver.name,
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&isl12022_rtc_ops, THIS_MODULE);
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return PTR_ERR_OR_ZERO(isl12022->rtc);
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}
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#ifdef CONFIG_OF
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static const struct of_device_id isl12022_dt_match[] = {
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{ .compatible = "isl,isl12022" }, /* for backward compat., don't use */
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{ .compatible = "isil,isl12022" },
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{ },
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};
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MODULE_DEVICE_TABLE(of, isl12022_dt_match);
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#endif
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static const struct i2c_device_id isl12022_id[] = {
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{ "isl12022", 0 },
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{ }
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};
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MODULE_DEVICE_TABLE(i2c, isl12022_id);
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static struct i2c_driver isl12022_driver = {
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.driver = {
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.name = "rtc-isl12022",
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#ifdef CONFIG_OF
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.of_match_table = of_match_ptr(isl12022_dt_match),
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#endif
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},
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.probe = isl12022_probe,
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.id_table = isl12022_id,
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};
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module_i2c_driver(isl12022_driver);
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MODULE_AUTHOR("roman.fietze@telemotive.de");
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MODULE_DESCRIPTION("ISL 12022 RTC driver");
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MODULE_LICENSE("GPL");
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MODULE_VERSION(DRV_VERSION);
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