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1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 | // SPDX-License-Identifier: GPL-2.0-only /* * An rtc/i2c driver for the EM Microelectronic EM3027 * Copyright 2011 CompuLab, Ltd. * * Author: Mike Rapoport <mike@compulab.co.il> * * Based on rtc-ds1672.c by Alessandro Zummo <a.zummo@towertech.it> */ #include <linux/i2c.h> #include <linux/rtc.h> #include <linux/bcd.h> #include <linux/module.h> #include <linux/of.h> /* Registers */ #define EM3027_REG_ON_OFF_CTRL 0x00 #define EM3027_REG_IRQ_CTRL 0x01 #define EM3027_REG_IRQ_FLAGS 0x02 #define EM3027_REG_STATUS 0x03 #define EM3027_REG_RST_CTRL 0x04 #define EM3027_REG_WATCH_SEC 0x08 #define EM3027_REG_WATCH_MIN 0x09 #define EM3027_REG_WATCH_HOUR 0x0a #define EM3027_REG_WATCH_DATE 0x0b #define EM3027_REG_WATCH_DAY 0x0c #define EM3027_REG_WATCH_MON 0x0d #define EM3027_REG_WATCH_YEAR 0x0e #define EM3027_REG_ALARM_SEC 0x10 #define EM3027_REG_ALARM_MIN 0x11 #define EM3027_REG_ALARM_HOUR 0x12 #define EM3027_REG_ALARM_DATE 0x13 #define EM3027_REG_ALARM_DAY 0x14 #define EM3027_REG_ALARM_MON 0x15 #define EM3027_REG_ALARM_YEAR 0x16 static struct i2c_driver em3027_driver; static int em3027_get_time(struct device *dev, struct rtc_time *tm) { struct i2c_client *client = to_i2c_client(dev); unsigned char addr = EM3027_REG_WATCH_SEC; unsigned char buf[7]; struct i2c_msg msgs[] = { {/* setup read addr */ .addr = client->addr, .len = 1, .buf = &addr }, {/* read time/date */ .addr = client->addr, .flags = I2C_M_RD, .len = 7, .buf = buf }, }; /* read time/date registers */ if ((i2c_transfer(client->adapter, &msgs[0], 2)) != 2) { dev_err(&client->dev, "%s: read error\n", __func__); return -EIO; } tm->tm_sec = bcd2bin(buf[0]); tm->tm_min = bcd2bin(buf[1]); tm->tm_hour = bcd2bin(buf[2]); tm->tm_mday = bcd2bin(buf[3]); tm->tm_wday = bcd2bin(buf[4]); tm->tm_mon = bcd2bin(buf[5]) - 1; tm->tm_year = bcd2bin(buf[6]) + 100; return 0; } static int em3027_set_time(struct device *dev, struct rtc_time *tm) { struct i2c_client *client = to_i2c_client(dev); unsigned char buf[8]; struct i2c_msg msg = { .addr = client->addr, .len = 8, .buf = buf, /* write time/date */ }; buf[0] = EM3027_REG_WATCH_SEC; buf[1] = bin2bcd(tm->tm_sec); buf[2] = bin2bcd(tm->tm_min); buf[3] = bin2bcd(tm->tm_hour); buf[4] = bin2bcd(tm->tm_mday); buf[5] = bin2bcd(tm->tm_wday); buf[6] = bin2bcd(tm->tm_mon + 1); buf[7] = bin2bcd(tm->tm_year % 100); /* write time/date registers */ if ((i2c_transfer(client->adapter, &msg, 1)) != 1) { dev_err(&client->dev, "%s: write error\n", __func__); return -EIO; } return 0; } static const struct rtc_class_ops em3027_rtc_ops = { .read_time = em3027_get_time, .set_time = em3027_set_time, }; static int em3027_probe(struct i2c_client *client) { struct rtc_device *rtc; if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) return -ENODEV; rtc = devm_rtc_device_register(&client->dev, em3027_driver.driver.name, &em3027_rtc_ops, THIS_MODULE); if (IS_ERR(rtc)) return PTR_ERR(rtc); i2c_set_clientdata(client, rtc); return 0; } static const struct i2c_device_id em3027_id[] = { { "em3027", 0 }, { } }; MODULE_DEVICE_TABLE(i2c, em3027_id); #ifdef CONFIG_OF static const struct of_device_id em3027_of_match[] = { { .compatible = "emmicro,em3027", }, {} }; MODULE_DEVICE_TABLE(of, em3027_of_match); #endif static struct i2c_driver em3027_driver = { .driver = { .name = "rtc-em3027", .of_match_table = of_match_ptr(em3027_of_match), }, .probe_new = em3027_probe, .id_table = em3027_id, }; module_i2c_driver(em3027_driver); MODULE_AUTHOR("Mike Rapoport <mike@compulab.co.il>"); MODULE_DESCRIPTION("EM Microelectronic EM3027 RTC driver"); MODULE_LICENSE("GPL"); |