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