Alessandro Zummo | 1d98af8 | 2006-03-27 01:16:47 -0800 | [diff] [blame] | 1 | /* |
| 2 | * ST M48T86 / Dallas DS12887 RTC driver |
| 3 | * Copyright (c) 2006 Tower Technologies |
| 4 | * |
| 5 | * Author: Alessandro Zummo <a.zummo@towertech.it> |
| 6 | * |
| 7 | * This program is free software; you can redistribute it and/or modify |
| 8 | * it under the terms of the GNU General Public License version 2 as |
| 9 | * published by the Free Software Foundation. |
| 10 | * |
| 11 | * This drivers only supports the clock running in BCD and 24H mode. |
| 12 | * If it will be ever adapted to binary and 12H mode, care must be taken |
| 13 | * to not introduce bugs. |
| 14 | */ |
| 15 | |
| 16 | #include <linux/module.h> |
| 17 | #include <linux/rtc.h> |
| 18 | #include <linux/platform_device.h> |
| 19 | #include <linux/m48t86.h> |
| 20 | #include <linux/bcd.h> |
| 21 | |
| 22 | #define M48T86_REG_SEC 0x00 |
| 23 | #define M48T86_REG_SECALRM 0x01 |
| 24 | #define M48T86_REG_MIN 0x02 |
| 25 | #define M48T86_REG_MINALRM 0x03 |
Alessandro Zummo | f90a650 | 2006-04-10 22:54:42 -0700 | [diff] [blame] | 26 | #define M48T86_REG_HOUR 0x04 |
Alessandro Zummo | 1d98af8 | 2006-03-27 01:16:47 -0800 | [diff] [blame] | 27 | #define M48T86_REG_HOURALRM 0x05 |
| 28 | #define M48T86_REG_DOW 0x06 /* 1 = sunday */ |
| 29 | #define M48T86_REG_DOM 0x07 |
| 30 | #define M48T86_REG_MONTH 0x08 /* 1 - 12 */ |
| 31 | #define M48T86_REG_YEAR 0x09 /* 0 - 99 */ |
| 32 | #define M48T86_REG_A 0x0A |
| 33 | #define M48T86_REG_B 0x0B |
| 34 | #define M48T86_REG_C 0x0C |
| 35 | #define M48T86_REG_D 0x0D |
| 36 | |
| 37 | #define M48T86_REG_B_H24 (1 << 1) |
| 38 | #define M48T86_REG_B_DM (1 << 2) |
| 39 | #define M48T86_REG_B_SET (1 << 7) |
| 40 | #define M48T86_REG_D_VRT (1 << 7) |
| 41 | |
| 42 | #define DRV_VERSION "0.1" |
| 43 | |
| 44 | |
| 45 | static int m48t86_rtc_read_time(struct device *dev, struct rtc_time *tm) |
| 46 | { |
| 47 | unsigned char reg; |
| 48 | struct platform_device *pdev = to_platform_device(dev); |
| 49 | struct m48t86_ops *ops = pdev->dev.platform_data; |
| 50 | |
Andrew Morton | 2d7b20c | 2006-06-04 02:51:42 -0700 | [diff] [blame] | 51 | reg = ops->readbyte(M48T86_REG_B); |
Alessandro Zummo | 1d98af8 | 2006-03-27 01:16:47 -0800 | [diff] [blame] | 52 | |
| 53 | if (reg & M48T86_REG_B_DM) { |
| 54 | /* data (binary) mode */ |
Andrew Morton | 2d7b20c | 2006-06-04 02:51:42 -0700 | [diff] [blame] | 55 | tm->tm_sec = ops->readbyte(M48T86_REG_SEC); |
| 56 | tm->tm_min = ops->readbyte(M48T86_REG_MIN); |
| 57 | tm->tm_hour = ops->readbyte(M48T86_REG_HOUR) & 0x3F; |
| 58 | tm->tm_mday = ops->readbyte(M48T86_REG_DOM); |
Alessandro Zummo | 1d98af8 | 2006-03-27 01:16:47 -0800 | [diff] [blame] | 59 | /* tm_mon is 0-11 */ |
Andrew Morton | 2d7b20c | 2006-06-04 02:51:42 -0700 | [diff] [blame] | 60 | tm->tm_mon = ops->readbyte(M48T86_REG_MONTH) - 1; |
| 61 | tm->tm_year = ops->readbyte(M48T86_REG_YEAR) + 100; |
| 62 | tm->tm_wday = ops->readbyte(M48T86_REG_DOW); |
Alessandro Zummo | 1d98af8 | 2006-03-27 01:16:47 -0800 | [diff] [blame] | 63 | } else { |
| 64 | /* bcd mode */ |
Adrian Bunk | fe20ba7 | 2008-10-18 20:28:41 -0700 | [diff] [blame] | 65 | tm->tm_sec = bcd2bin(ops->readbyte(M48T86_REG_SEC)); |
| 66 | tm->tm_min = bcd2bin(ops->readbyte(M48T86_REG_MIN)); |
| 67 | tm->tm_hour = bcd2bin(ops->readbyte(M48T86_REG_HOUR) & 0x3F); |
| 68 | tm->tm_mday = bcd2bin(ops->readbyte(M48T86_REG_DOM)); |
Alessandro Zummo | 1d98af8 | 2006-03-27 01:16:47 -0800 | [diff] [blame] | 69 | /* tm_mon is 0-11 */ |
Adrian Bunk | fe20ba7 | 2008-10-18 20:28:41 -0700 | [diff] [blame] | 70 | tm->tm_mon = bcd2bin(ops->readbyte(M48T86_REG_MONTH)) - 1; |
| 71 | tm->tm_year = bcd2bin(ops->readbyte(M48T86_REG_YEAR)) + 100; |
| 72 | tm->tm_wday = bcd2bin(ops->readbyte(M48T86_REG_DOW)); |
Alessandro Zummo | 1d98af8 | 2006-03-27 01:16:47 -0800 | [diff] [blame] | 73 | } |
| 74 | |
| 75 | /* correct the hour if the clock is in 12h mode */ |
| 76 | if (!(reg & M48T86_REG_B_H24)) |
Andrew Morton | 2d7b20c | 2006-06-04 02:51:42 -0700 | [diff] [blame] | 77 | if (ops->readbyte(M48T86_REG_HOUR) & 0x80) |
Alessandro Zummo | 1d98af8 | 2006-03-27 01:16:47 -0800 | [diff] [blame] | 78 | tm->tm_hour += 12; |
| 79 | |
Wan ZongShun | 52142ed | 2010-08-10 18:02:17 -0700 | [diff] [blame^] | 80 | return rtc_valid_tm(tm); |
Alessandro Zummo | 1d98af8 | 2006-03-27 01:16:47 -0800 | [diff] [blame] | 81 | } |
| 82 | |
| 83 | static int m48t86_rtc_set_time(struct device *dev, struct rtc_time *tm) |
| 84 | { |
| 85 | unsigned char reg; |
| 86 | struct platform_device *pdev = to_platform_device(dev); |
| 87 | struct m48t86_ops *ops = pdev->dev.platform_data; |
| 88 | |
Andrew Morton | 2d7b20c | 2006-06-04 02:51:42 -0700 | [diff] [blame] | 89 | reg = ops->readbyte(M48T86_REG_B); |
Alessandro Zummo | 1d98af8 | 2006-03-27 01:16:47 -0800 | [diff] [blame] | 90 | |
| 91 | /* update flag and 24h mode */ |
| 92 | reg |= M48T86_REG_B_SET | M48T86_REG_B_H24; |
Andrew Morton | 2d7b20c | 2006-06-04 02:51:42 -0700 | [diff] [blame] | 93 | ops->writebyte(reg, M48T86_REG_B); |
Alessandro Zummo | 1d98af8 | 2006-03-27 01:16:47 -0800 | [diff] [blame] | 94 | |
| 95 | if (reg & M48T86_REG_B_DM) { |
| 96 | /* data (binary) mode */ |
Andrew Morton | 2d7b20c | 2006-06-04 02:51:42 -0700 | [diff] [blame] | 97 | ops->writebyte(tm->tm_sec, M48T86_REG_SEC); |
| 98 | ops->writebyte(tm->tm_min, M48T86_REG_MIN); |
| 99 | ops->writebyte(tm->tm_hour, M48T86_REG_HOUR); |
| 100 | ops->writebyte(tm->tm_mday, M48T86_REG_DOM); |
| 101 | ops->writebyte(tm->tm_mon + 1, M48T86_REG_MONTH); |
| 102 | ops->writebyte(tm->tm_year % 100, M48T86_REG_YEAR); |
| 103 | ops->writebyte(tm->tm_wday, M48T86_REG_DOW); |
Alessandro Zummo | 1d98af8 | 2006-03-27 01:16:47 -0800 | [diff] [blame] | 104 | } else { |
| 105 | /* bcd mode */ |
Adrian Bunk | fe20ba7 | 2008-10-18 20:28:41 -0700 | [diff] [blame] | 106 | ops->writebyte(bin2bcd(tm->tm_sec), M48T86_REG_SEC); |
| 107 | ops->writebyte(bin2bcd(tm->tm_min), M48T86_REG_MIN); |
| 108 | ops->writebyte(bin2bcd(tm->tm_hour), M48T86_REG_HOUR); |
| 109 | ops->writebyte(bin2bcd(tm->tm_mday), M48T86_REG_DOM); |
| 110 | ops->writebyte(bin2bcd(tm->tm_mon + 1), M48T86_REG_MONTH); |
| 111 | ops->writebyte(bin2bcd(tm->tm_year % 100), M48T86_REG_YEAR); |
| 112 | ops->writebyte(bin2bcd(tm->tm_wday), M48T86_REG_DOW); |
Alessandro Zummo | 1d98af8 | 2006-03-27 01:16:47 -0800 | [diff] [blame] | 113 | } |
| 114 | |
| 115 | /* update ended */ |
| 116 | reg &= ~M48T86_REG_B_SET; |
Andrew Morton | 2d7b20c | 2006-06-04 02:51:42 -0700 | [diff] [blame] | 117 | ops->writebyte(reg, M48T86_REG_B); |
Alessandro Zummo | 1d98af8 | 2006-03-27 01:16:47 -0800 | [diff] [blame] | 118 | |
| 119 | return 0; |
| 120 | } |
| 121 | |
| 122 | static int m48t86_rtc_proc(struct device *dev, struct seq_file *seq) |
| 123 | { |
| 124 | unsigned char reg; |
| 125 | struct platform_device *pdev = to_platform_device(dev); |
| 126 | struct m48t86_ops *ops = pdev->dev.platform_data; |
| 127 | |
Andrew Morton | 2d7b20c | 2006-06-04 02:51:42 -0700 | [diff] [blame] | 128 | reg = ops->readbyte(M48T86_REG_B); |
Alessandro Zummo | 1d98af8 | 2006-03-27 01:16:47 -0800 | [diff] [blame] | 129 | |
Alessandro Zummo | 1d98af8 | 2006-03-27 01:16:47 -0800 | [diff] [blame] | 130 | seq_printf(seq, "mode\t\t: %s\n", |
| 131 | (reg & M48T86_REG_B_DM) ? "binary" : "bcd"); |
| 132 | |
Andrew Morton | 2d7b20c | 2006-06-04 02:51:42 -0700 | [diff] [blame] | 133 | reg = ops->readbyte(M48T86_REG_D); |
Alessandro Zummo | 1d98af8 | 2006-03-27 01:16:47 -0800 | [diff] [blame] | 134 | |
| 135 | seq_printf(seq, "battery\t\t: %s\n", |
| 136 | (reg & M48T86_REG_D_VRT) ? "ok" : "exhausted"); |
| 137 | |
| 138 | return 0; |
| 139 | } |
| 140 | |
David Brownell | ff8371a | 2006-09-30 23:28:17 -0700 | [diff] [blame] | 141 | static const struct rtc_class_ops m48t86_rtc_ops = { |
Alessandro Zummo | 1d98af8 | 2006-03-27 01:16:47 -0800 | [diff] [blame] | 142 | .read_time = m48t86_rtc_read_time, |
| 143 | .set_time = m48t86_rtc_set_time, |
| 144 | .proc = m48t86_rtc_proc, |
| 145 | }; |
| 146 | |
| 147 | static int __devinit m48t86_rtc_probe(struct platform_device *dev) |
| 148 | { |
| 149 | unsigned char reg; |
| 150 | struct m48t86_ops *ops = dev->dev.platform_data; |
| 151 | struct rtc_device *rtc = rtc_device_register("m48t86", |
| 152 | &dev->dev, &m48t86_rtc_ops, THIS_MODULE); |
| 153 | |
Alessandro Zummo | d1d65b7 | 2006-04-10 22:54:45 -0700 | [diff] [blame] | 154 | if (IS_ERR(rtc)) |
Alessandro Zummo | 1d98af8 | 2006-03-27 01:16:47 -0800 | [diff] [blame] | 155 | return PTR_ERR(rtc); |
Alessandro Zummo | 1d98af8 | 2006-03-27 01:16:47 -0800 | [diff] [blame] | 156 | |
| 157 | platform_set_drvdata(dev, rtc); |
| 158 | |
| 159 | /* read battery status */ |
Andrew Morton | 2d7b20c | 2006-06-04 02:51:42 -0700 | [diff] [blame] | 160 | reg = ops->readbyte(M48T86_REG_D); |
Alessandro Zummo | 1d98af8 | 2006-03-27 01:16:47 -0800 | [diff] [blame] | 161 | dev_info(&dev->dev, "battery %s\n", |
| 162 | (reg & M48T86_REG_D_VRT) ? "ok" : "exhausted"); |
| 163 | |
| 164 | return 0; |
| 165 | } |
| 166 | |
| 167 | static int __devexit m48t86_rtc_remove(struct platform_device *dev) |
| 168 | { |
| 169 | struct rtc_device *rtc = platform_get_drvdata(dev); |
| 170 | |
| 171 | if (rtc) |
| 172 | rtc_device_unregister(rtc); |
| 173 | |
| 174 | platform_set_drvdata(dev, NULL); |
| 175 | |
| 176 | return 0; |
| 177 | } |
| 178 | |
| 179 | static struct platform_driver m48t86_rtc_platform_driver = { |
| 180 | .driver = { |
| 181 | .name = "rtc-m48t86", |
| 182 | .owner = THIS_MODULE, |
| 183 | }, |
| 184 | .probe = m48t86_rtc_probe, |
| 185 | .remove = __devexit_p(m48t86_rtc_remove), |
| 186 | }; |
| 187 | |
| 188 | static int __init m48t86_rtc_init(void) |
| 189 | { |
| 190 | return platform_driver_register(&m48t86_rtc_platform_driver); |
| 191 | } |
| 192 | |
| 193 | static void __exit m48t86_rtc_exit(void) |
| 194 | { |
| 195 | platform_driver_unregister(&m48t86_rtc_platform_driver); |
| 196 | } |
| 197 | |
| 198 | MODULE_AUTHOR("Alessandro Zummo <a.zummo@towertech.it>"); |
| 199 | MODULE_DESCRIPTION("M48T86 RTC driver"); |
| 200 | MODULE_LICENSE("GPL"); |
| 201 | MODULE_VERSION(DRV_VERSION); |
Kay Sievers | ad28a07 | 2008-04-10 21:29:25 -0700 | [diff] [blame] | 202 | MODULE_ALIAS("platform:rtc-m48t86"); |
Alessandro Zummo | 1d98af8 | 2006-03-27 01:16:47 -0800 | [diff] [blame] | 203 | |
| 204 | module_init(m48t86_rtc_init); |
| 205 | module_exit(m48t86_rtc_exit); |