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183 lines
5.3 KiB
183 lines
5.3 KiB
/* |
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* ST M48T86 / Dallas DS12887 RTC driver |
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* Copyright (c) 2006 Tower Technologies |
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* |
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* Author: 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 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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* This drivers only supports the clock running in BCD and 24H mode. |
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* If it will be ever adapted to binary and 12H mode, care must be taken |
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* to not introduce bugs. |
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*/ |
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#include <linux/module.h> |
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#include <linux/rtc.h> |
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#include <linux/platform_device.h> |
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#include <linux/m48t86.h> |
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#include <linux/bcd.h> |
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#define M48T86_REG_SEC 0x00 |
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#define M48T86_REG_SECALRM 0x01 |
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#define M48T86_REG_MIN 0x02 |
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#define M48T86_REG_MINALRM 0x03 |
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#define M48T86_REG_HOUR 0x04 |
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#define M48T86_REG_HOURALRM 0x05 |
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#define M48T86_REG_DOW 0x06 /* 1 = sunday */ |
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#define M48T86_REG_DOM 0x07 |
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#define M48T86_REG_MONTH 0x08 /* 1 - 12 */ |
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#define M48T86_REG_YEAR 0x09 /* 0 - 99 */ |
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#define M48T86_REG_A 0x0A |
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#define M48T86_REG_B 0x0B |
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#define M48T86_REG_C 0x0C |
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#define M48T86_REG_D 0x0D |
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#define M48T86_REG_B_H24 (1 << 1) |
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#define M48T86_REG_B_DM (1 << 2) |
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#define M48T86_REG_B_SET (1 << 7) |
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#define M48T86_REG_D_VRT (1 << 7) |
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#define DRV_VERSION "0.1" |
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static int m48t86_rtc_read_time(struct device *dev, struct rtc_time *tm) |
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{ |
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unsigned char reg; |
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struct platform_device *pdev = to_platform_device(dev); |
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struct m48t86_ops *ops = dev_get_platdata(&pdev->dev); |
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reg = ops->readbyte(M48T86_REG_B); |
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if (reg & M48T86_REG_B_DM) { |
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/* data (binary) mode */ |
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tm->tm_sec = ops->readbyte(M48T86_REG_SEC); |
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tm->tm_min = ops->readbyte(M48T86_REG_MIN); |
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tm->tm_hour = ops->readbyte(M48T86_REG_HOUR) & 0x3F; |
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tm->tm_mday = ops->readbyte(M48T86_REG_DOM); |
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/* tm_mon is 0-11 */ |
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tm->tm_mon = ops->readbyte(M48T86_REG_MONTH) - 1; |
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tm->tm_year = ops->readbyte(M48T86_REG_YEAR) + 100; |
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tm->tm_wday = ops->readbyte(M48T86_REG_DOW); |
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} else { |
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/* bcd mode */ |
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tm->tm_sec = bcd2bin(ops->readbyte(M48T86_REG_SEC)); |
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tm->tm_min = bcd2bin(ops->readbyte(M48T86_REG_MIN)); |
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tm->tm_hour = bcd2bin(ops->readbyte(M48T86_REG_HOUR) & 0x3F); |
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tm->tm_mday = bcd2bin(ops->readbyte(M48T86_REG_DOM)); |
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/* tm_mon is 0-11 */ |
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tm->tm_mon = bcd2bin(ops->readbyte(M48T86_REG_MONTH)) - 1; |
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tm->tm_year = bcd2bin(ops->readbyte(M48T86_REG_YEAR)) + 100; |
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tm->tm_wday = bcd2bin(ops->readbyte(M48T86_REG_DOW)); |
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} |
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/* correct the hour if the clock is in 12h mode */ |
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if (!(reg & M48T86_REG_B_H24)) |
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if (ops->readbyte(M48T86_REG_HOUR) & 0x80) |
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tm->tm_hour += 12; |
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return rtc_valid_tm(tm); |
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} |
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static int m48t86_rtc_set_time(struct device *dev, struct rtc_time *tm) |
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{ |
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unsigned char reg; |
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struct platform_device *pdev = to_platform_device(dev); |
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struct m48t86_ops *ops = dev_get_platdata(&pdev->dev); |
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reg = ops->readbyte(M48T86_REG_B); |
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/* update flag and 24h mode */ |
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reg |= M48T86_REG_B_SET | M48T86_REG_B_H24; |
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ops->writebyte(reg, M48T86_REG_B); |
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if (reg & M48T86_REG_B_DM) { |
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/* data (binary) mode */ |
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ops->writebyte(tm->tm_sec, M48T86_REG_SEC); |
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ops->writebyte(tm->tm_min, M48T86_REG_MIN); |
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ops->writebyte(tm->tm_hour, M48T86_REG_HOUR); |
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ops->writebyte(tm->tm_mday, M48T86_REG_DOM); |
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ops->writebyte(tm->tm_mon + 1, M48T86_REG_MONTH); |
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ops->writebyte(tm->tm_year % 100, M48T86_REG_YEAR); |
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ops->writebyte(tm->tm_wday, M48T86_REG_DOW); |
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} else { |
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/* bcd mode */ |
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ops->writebyte(bin2bcd(tm->tm_sec), M48T86_REG_SEC); |
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ops->writebyte(bin2bcd(tm->tm_min), M48T86_REG_MIN); |
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ops->writebyte(bin2bcd(tm->tm_hour), M48T86_REG_HOUR); |
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ops->writebyte(bin2bcd(tm->tm_mday), M48T86_REG_DOM); |
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ops->writebyte(bin2bcd(tm->tm_mon + 1), M48T86_REG_MONTH); |
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ops->writebyte(bin2bcd(tm->tm_year % 100), M48T86_REG_YEAR); |
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ops->writebyte(bin2bcd(tm->tm_wday), M48T86_REG_DOW); |
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} |
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/* update ended */ |
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reg &= ~M48T86_REG_B_SET; |
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ops->writebyte(reg, M48T86_REG_B); |
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return 0; |
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} |
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static int m48t86_rtc_proc(struct device *dev, struct seq_file *seq) |
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{ |
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unsigned char reg; |
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struct platform_device *pdev = to_platform_device(dev); |
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struct m48t86_ops *ops = dev_get_platdata(&pdev->dev); |
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reg = ops->readbyte(M48T86_REG_B); |
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seq_printf(seq, "mode\t\t: %s\n", |
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(reg & M48T86_REG_B_DM) ? "binary" : "bcd"); |
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reg = ops->readbyte(M48T86_REG_D); |
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seq_printf(seq, "battery\t\t: %s\n", |
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(reg & M48T86_REG_D_VRT) ? "ok" : "exhausted"); |
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return 0; |
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} |
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static const struct rtc_class_ops m48t86_rtc_ops = { |
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.read_time = m48t86_rtc_read_time, |
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.set_time = m48t86_rtc_set_time, |
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.proc = m48t86_rtc_proc, |
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}; |
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static int m48t86_rtc_probe(struct platform_device *dev) |
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{ |
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unsigned char reg; |
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struct m48t86_ops *ops = dev_get_platdata(&dev->dev); |
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struct rtc_device *rtc; |
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rtc = devm_rtc_device_register(&dev->dev, "m48t86", |
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&m48t86_rtc_ops, THIS_MODULE); |
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if (IS_ERR(rtc)) |
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return PTR_ERR(rtc); |
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platform_set_drvdata(dev, rtc); |
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/* read battery status */ |
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reg = ops->readbyte(M48T86_REG_D); |
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dev_info(&dev->dev, "battery %s\n", |
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(reg & M48T86_REG_D_VRT) ? "ok" : "exhausted"); |
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return 0; |
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} |
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static struct platform_driver m48t86_rtc_platform_driver = { |
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.driver = { |
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.name = "rtc-m48t86", |
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.owner = THIS_MODULE, |
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}, |
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.probe = m48t86_rtc_probe, |
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}; |
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module_platform_driver(m48t86_rtc_platform_driver); |
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MODULE_AUTHOR("Alessandro Zummo <a.zummo@towertech.it>"); |
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MODULE_DESCRIPTION("M48T86 RTC driver"); |
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MODULE_LICENSE("GPL"); |
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MODULE_VERSION(DRV_VERSION); |
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MODULE_ALIAS("platform:rtc-m48t86");
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