| /* |
| * Driver for Epson RTC-7301SF/DG |
| * |
| * Copyright (C) 2009 Jose Vasconcellos |
| * |
| * 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. |
| */ |
| |
| #include <linux/module.h> |
| #include <linux/rtc.h> |
| #include <linux/platform_device.h> |
| #include <linux/io.h> |
| #include <linux/delay.h> |
| #include <linux/bcd.h> |
| |
| #define RTC_NAME "rtc7301" |
| #define RTC_VERSION "0.1" |
| |
| /* Epson RTC-7301 register addresses */ |
| #define RTC7301_SEC 0x00 |
| #define RTC7301_SEC10 0x01 |
| #define RTC7301_MIN 0x02 |
| #define RTC7301_MIN10 0x03 |
| #define RTC7301_HOUR 0x04 |
| #define RTC7301_HOUR10 0x05 |
| #define RTC7301_WEEKDAY 0x06 |
| #define RTC7301_DAY 0x07 |
| #define RTC7301_DAY10 0x08 |
| #define RTC7301_MON 0x09 |
| #define RTC7301_MON10 0x0A |
| #define RTC7301_YEAR 0x0B |
| #define RTC7301_YEAR10 0x0C |
| #define RTC7301_YEAR100 0x0D |
| #define RTC7301_YEAR1000 0x0E |
| #define RTC7301_CTRLREG 0x0F |
| |
| static uint8_t __iomem *rtc7301_base; |
| |
| #define read_reg(offset) (readb(rtc7301_base + offset) & 0xf) |
| #define write_reg(offset, data) writeb(data, rtc7301_base + (offset)) |
| |
| #define rtc7301_isbusy() (read_reg(RTC7301_CTRLREG) & 1) |
| |
| static void rtc7301_init_settings(void) |
| { |
| int i; |
| |
| write_reg(RTC7301_CTRLREG, 2); |
| write_reg(RTC7301_YEAR1000, 2); |
| udelay(122); |
| |
| /* bank 1 */ |
| write_reg(RTC7301_CTRLREG, 6); |
| for (i=0; i<15; i++) |
| write_reg(i, 0); |
| |
| /* bank 2 */ |
| write_reg(RTC7301_CTRLREG, 14); |
| for (i=0; i<15; i++) |
| write_reg(i, 0); |
| write_reg(RTC7301_CTRLREG, 0); |
| } |
| |
| static int rtc7301_get_datetime(struct device *dev, struct rtc_time *dt) |
| { |
| int cnt; |
| uint8_t buf[16]; |
| |
| cnt = 0; |
| while (rtc7301_isbusy()) { |
| udelay(244); |
| if (cnt++ > 100) { |
| dev_err(dev, "%s: timeout error %x\n", __func__, rtc7301_base[RTC7301_CTRLREG]); |
| return -EIO; |
| } |
| } |
| |
| for (cnt=0; cnt<16; cnt++) |
| buf[cnt] = read_reg(cnt); |
| |
| if (buf[RTC7301_SEC10] & 8) { |
| dev_err(dev, "%s: RTC not set\n", __func__); |
| return -EINVAL; |
| } |
| |
| memset(dt, 0, sizeof(*dt)); |
| |
| dt->tm_sec = buf[RTC7301_SEC] + buf[RTC7301_SEC10]*10; |
| dt->tm_min = buf[RTC7301_MIN] + buf[RTC7301_MIN10]*10; |
| dt->tm_hour = buf[RTC7301_HOUR] + buf[RTC7301_HOUR10]*10; |
| |
| dt->tm_mday = buf[RTC7301_DAY] + buf[RTC7301_DAY10]*10; |
| dt->tm_mon = buf[RTC7301_MON] + buf[RTC7301_MON10]*10 - 1; |
| dt->tm_year = buf[RTC7301_YEAR] + buf[RTC7301_YEAR10]*10 + |
| buf[RTC7301_YEAR100]*100 + |
| ((buf[RTC7301_YEAR1000] & 3)*1000) - 1900; |
| |
| /* the rtc device may contain illegal values on power up |
| * according to the data sheet. make sure they are valid. |
| */ |
| |
| return rtc_valid_tm(dt); |
| } |
| |
| static int rtc7301_set_datetime(struct device *dev, struct rtc_time *dt) |
| { |
| int data; |
| |
| data = dt->tm_year + 1900; |
| if (data >= 2100 || data < 1900) |
| return -EINVAL; |
| |
| write_reg(RTC7301_CTRLREG, 2); |
| udelay(122); |
| |
| data = bin2bcd(dt->tm_sec); |
| write_reg(RTC7301_SEC, data); |
| write_reg(RTC7301_SEC10, (data >> 4)); |
| |
| data = bin2bcd(dt->tm_min); |
| write_reg(RTC7301_MIN, data ); |
| write_reg(RTC7301_MIN10, (data >> 4)); |
| |
| data = bin2bcd(dt->tm_hour); |
| write_reg(RTC7301_HOUR, data); |
| write_reg(RTC7301_HOUR10, (data >> 4)); |
| |
| data = bin2bcd(dt->tm_mday); |
| write_reg(RTC7301_DAY, data); |
| write_reg(RTC7301_DAY10, (data>> 4)); |
| |
| data = bin2bcd(dt->tm_mon + 1); |
| write_reg(RTC7301_MON, data); |
| write_reg(RTC7301_MON10, (data >> 4)); |
| |
| data = bin2bcd(dt->tm_year % 100); |
| write_reg(RTC7301_YEAR, data); |
| write_reg(RTC7301_YEAR10, (data >> 4)); |
| data = bin2bcd((1900 + dt->tm_year) / 100); |
| write_reg(RTC7301_YEAR100, data); |
| |
| data = bin2bcd(dt->tm_wday); |
| write_reg(RTC7301_WEEKDAY, data); |
| |
| write_reg(RTC7301_CTRLREG, 0); |
| |
| return 0; |
| } |
| |
| static const struct rtc_class_ops rtc7301_rtc_ops = { |
| .read_time = rtc7301_get_datetime, |
| .set_time = rtc7301_set_datetime, |
| }; |
| |
| static int __devinit rtc7301_probe(struct platform_device *pdev) |
| { |
| struct rtc_device *rtc; |
| struct resource *res; |
| |
| res = platform_get_resource(pdev, IORESOURCE_MEM, 0); |
| if (!res) |
| return -ENOENT; |
| |
| rtc7301_base = ioremap_nocache(res->start, 0x1000 /*res->end - res->start + 1*/); |
| if (!rtc7301_base) |
| return -EINVAL; |
| |
| rtc = rtc_device_register(RTC_NAME, &pdev->dev, |
| &rtc7301_rtc_ops, THIS_MODULE); |
| if (IS_ERR(rtc)) { |
| iounmap(rtc7301_base); |
| return PTR_ERR(rtc); |
| } |
| |
| platform_set_drvdata(pdev, rtc); |
| |
| rtc7301_init_settings(); |
| return 0; |
| } |
| |
| static int __devexit rtc7301_remove(struct platform_device *pdev) |
| { |
| struct rtc_device *rtc = platform_get_drvdata(pdev); |
| |
| if (rtc) |
| rtc_device_unregister(rtc); |
| if (rtc7301_base) |
| iounmap(rtc7301_base); |
| return 0; |
| } |
| |
| static struct platform_driver rtc7301_driver = { |
| .driver = { |
| .name = RTC_NAME, |
| .owner = THIS_MODULE, |
| }, |
| .probe = rtc7301_probe, |
| .remove = __devexit_p(rtc7301_remove), |
| }; |
| |
| static __init int rtc7301_init(void) |
| { |
| return platform_driver_register(&rtc7301_driver); |
| } |
| module_init(rtc7301_init); |
| |
| static __exit void rtc7301_exit(void) |
| { |
| platform_driver_unregister(&rtc7301_driver); |
| } |
| module_exit(rtc7301_exit); |
| |
| MODULE_DESCRIPTION("Epson 7301 RTC driver"); |
| MODULE_AUTHOR("Jose Vasconcellos <jvasco@verizon.net>"); |
| MODULE_LICENSE("GPL"); |
| MODULE_ALIAS("platform:" RTC_NAME); |
| MODULE_VERSION(RTC_VERSION); |