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159 lines
3.7 KiB
159 lines
3.7 KiB
// SPDX-License-Identifier: GPL-2.0-only |
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/* |
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* An rtc/i2c driver for the EM Microelectronic EM3027 |
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* Copyright 2011 CompuLab, Ltd. |
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* |
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* Author: Mike Rapoport <[email protected]> |
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* |
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* Based on rtc-ds1672.c by Alessandro Zummo <[email protected]> |
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*/ |
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#include <linux/i2c.h> |
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#include <linux/rtc.h> |
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#include <linux/bcd.h> |
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#include <linux/module.h> |
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#include <linux/of.h> |
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/* Registers */ |
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#define EM3027_REG_ON_OFF_CTRL 0x00 |
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#define EM3027_REG_IRQ_CTRL 0x01 |
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#define EM3027_REG_IRQ_FLAGS 0x02 |
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#define EM3027_REG_STATUS 0x03 |
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#define EM3027_REG_RST_CTRL 0x04 |
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#define EM3027_REG_WATCH_SEC 0x08 |
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#define EM3027_REG_WATCH_MIN 0x09 |
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#define EM3027_REG_WATCH_HOUR 0x0a |
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#define EM3027_REG_WATCH_DATE 0x0b |
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#define EM3027_REG_WATCH_DAY 0x0c |
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#define EM3027_REG_WATCH_MON 0x0d |
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#define EM3027_REG_WATCH_YEAR 0x0e |
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#define EM3027_REG_ALARM_SEC 0x10 |
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#define EM3027_REG_ALARM_MIN 0x11 |
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#define EM3027_REG_ALARM_HOUR 0x12 |
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#define EM3027_REG_ALARM_DATE 0x13 |
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#define EM3027_REG_ALARM_DAY 0x14 |
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#define EM3027_REG_ALARM_MON 0x15 |
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#define EM3027_REG_ALARM_YEAR 0x16 |
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static struct i2c_driver em3027_driver; |
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static int em3027_get_time(struct device *dev, struct rtc_time *tm) |
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{ |
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struct i2c_client *client = to_i2c_client(dev); |
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unsigned char addr = EM3027_REG_WATCH_SEC; |
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unsigned char buf[7]; |
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struct i2c_msg msgs[] = { |
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{/* setup read addr */ |
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.addr = client->addr, |
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.len = 1, |
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.buf = &addr |
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}, |
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{/* read time/date */ |
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.addr = client->addr, |
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.flags = I2C_M_RD, |
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.len = 7, |
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.buf = buf |
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}, |
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}; |
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/* read time/date registers */ |
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if ((i2c_transfer(client->adapter, &msgs[0], 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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tm->tm_sec = bcd2bin(buf[0]); |
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tm->tm_min = bcd2bin(buf[1]); |
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tm->tm_hour = bcd2bin(buf[2]); |
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tm->tm_mday = bcd2bin(buf[3]); |
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tm->tm_wday = bcd2bin(buf[4]); |
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tm->tm_mon = bcd2bin(buf[5]) - 1; |
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tm->tm_year = bcd2bin(buf[6]) + 100; |
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return 0; |
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} |
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static int em3027_set_time(struct device *dev, struct rtc_time *tm) |
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{ |
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struct i2c_client *client = to_i2c_client(dev); |
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unsigned char buf[8]; |
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struct i2c_msg msg = { |
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.addr = client->addr, |
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.len = 8, |
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.buf = buf, /* write time/date */ |
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}; |
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buf[0] = EM3027_REG_WATCH_SEC; |
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buf[1] = bin2bcd(tm->tm_sec); |
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buf[2] = bin2bcd(tm->tm_min); |
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buf[3] = bin2bcd(tm->tm_hour); |
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buf[4] = bin2bcd(tm->tm_mday); |
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buf[5] = bin2bcd(tm->tm_wday); |
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buf[6] = bin2bcd(tm->tm_mon + 1); |
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buf[7] = bin2bcd(tm->tm_year % 100); |
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/* write time/date registers */ |
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if ((i2c_transfer(client->adapter, &msg, 1)) != 1) { |
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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 const struct rtc_class_ops em3027_rtc_ops = { |
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.read_time = em3027_get_time, |
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.set_time = em3027_set_time, |
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}; |
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static int em3027_probe(struct i2c_client *client, |
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const struct i2c_device_id *id) |
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{ |
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struct rtc_device *rtc; |
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if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) |
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return -ENODEV; |
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rtc = devm_rtc_device_register(&client->dev, em3027_driver.driver.name, |
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&em3027_rtc_ops, THIS_MODULE); |
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if (IS_ERR(rtc)) |
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return PTR_ERR(rtc); |
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i2c_set_clientdata(client, rtc); |
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return 0; |
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} |
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static const struct i2c_device_id em3027_id[] = { |
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{ "em3027", 0 }, |
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{ } |
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}; |
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MODULE_DEVICE_TABLE(i2c, em3027_id); |
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#ifdef CONFIG_OF |
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static const struct of_device_id em3027_of_match[] = { |
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{ .compatible = "emmicro,em3027", }, |
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{} |
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}; |
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MODULE_DEVICE_TABLE(of, em3027_of_match); |
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#endif |
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static struct i2c_driver em3027_driver = { |
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.driver = { |
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.name = "rtc-em3027", |
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.of_match_table = of_match_ptr(em3027_of_match), |
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}, |
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.probe = &em3027_probe, |
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.id_table = em3027_id, |
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}; |
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module_i2c_driver(em3027_driver); |
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MODULE_AUTHOR("Mike Rapoport <[email protected]>"); |
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MODULE_DESCRIPTION("EM Microelectronic EM3027 RTC driver"); |
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MODULE_LICENSE("GPL");
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