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Atsushi Nemoto5ec3e4b2006-06-25 05:48:29 -07001/*
2 * An rtc driver for the Dallas DS1742
3 *
4 * Copyright (C) 2006 Atsushi Nemoto <anemo@mba.ocn.ne.jp>
5 *
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License version 2 as
8 * published by the Free Software Foundation.
Torsten Ertbjerg Rasmussenf9231a02006-12-06 20:39:41 -08009 *
10 * Copyright (C) 2006 Torsten Ertbjerg Rasmussen <tr@newtec.dk>
11 * - nvram size determined from resource
12 * - this ds1742 driver now supports ds1743.
Atsushi Nemoto5ec3e4b2006-06-25 05:48:29 -070013 */
14
15#include <linux/bcd.h>
16#include <linux/init.h>
17#include <linux/kernel.h>
Tejun Heo5a0e3ad2010-03-24 17:04:11 +090018#include <linux/gfp.h>
Atsushi Nemoto5ec3e4b2006-06-25 05:48:29 -070019#include <linux/delay.h>
20#include <linux/jiffies.h>
21#include <linux/rtc.h>
22#include <linux/platform_device.h>
23#include <linux/io.h>
Paul Gortmaker21138522011-05-27 09:57:25 -040024#include <linux/module.h>
Atsushi Nemoto5ec3e4b2006-06-25 05:48:29 -070025
Atsushi Nemotoac18eb62009-12-15 16:46:02 -080026#define DRV_VERSION "0.4"
Atsushi Nemoto5ec3e4b2006-06-25 05:48:29 -070027
Torsten Ertbjerg Rasmussenf9231a02006-12-06 20:39:41 -080028#define RTC_SIZE 8
Atsushi Nemoto5ec3e4b2006-06-25 05:48:29 -070029
Torsten Ertbjerg Rasmussenf9231a02006-12-06 20:39:41 -080030#define RTC_CONTROL 0
31#define RTC_CENTURY 0
32#define RTC_SECONDS 1
33#define RTC_MINUTES 2
34#define RTC_HOURS 3
35#define RTC_DAY 4
36#define RTC_DATE 5
37#define RTC_MONTH 6
38#define RTC_YEAR 7
Atsushi Nemoto5ec3e4b2006-06-25 05:48:29 -070039
40#define RTC_CENTURY_MASK 0x3f
41#define RTC_SECONDS_MASK 0x7f
42#define RTC_DAY_MASK 0x07
43
44/* Bits in the Control/Century register */
45#define RTC_WRITE 0x80
46#define RTC_READ 0x40
47
48/* Bits in the Seconds register */
49#define RTC_STOP 0x80
50
51/* Bits in the Day register */
52#define RTC_BATT_FLAG 0x80
53
54struct rtc_plat_data {
55 struct rtc_device *rtc;
Torsten Ertbjerg Rasmussenf9231a02006-12-06 20:39:41 -080056 void __iomem *ioaddr_nvram;
57 void __iomem *ioaddr_rtc;
58 size_t size_nvram;
59 size_t size;
Atsushi Nemoto5ec3e4b2006-06-25 05:48:29 -070060 unsigned long last_jiffies;
Torsten Ertbjerg Rasmussen3a729702009-06-17 16:26:07 -070061 struct bin_attribute nvram_attr;
Atsushi Nemoto5ec3e4b2006-06-25 05:48:29 -070062};
63
64static int ds1742_rtc_set_time(struct device *dev, struct rtc_time *tm)
65{
66 struct platform_device *pdev = to_platform_device(dev);
67 struct rtc_plat_data *pdata = platform_get_drvdata(pdev);
Torsten Ertbjerg Rasmussenf9231a02006-12-06 20:39:41 -080068 void __iomem *ioaddr = pdata->ioaddr_rtc;
Atsushi Nemoto5ec3e4b2006-06-25 05:48:29 -070069 u8 century;
70
Adrian Bunkfe20ba72008-10-18 20:28:41 -070071 century = bin2bcd((tm->tm_year + 1900) / 100);
Atsushi Nemoto5ec3e4b2006-06-25 05:48:29 -070072
73 writeb(RTC_WRITE, ioaddr + RTC_CONTROL);
74
Adrian Bunkfe20ba72008-10-18 20:28:41 -070075 writeb(bin2bcd(tm->tm_year % 100), ioaddr + RTC_YEAR);
76 writeb(bin2bcd(tm->tm_mon + 1), ioaddr + RTC_MONTH);
77 writeb(bin2bcd(tm->tm_wday) & RTC_DAY_MASK, ioaddr + RTC_DAY);
78 writeb(bin2bcd(tm->tm_mday), ioaddr + RTC_DATE);
79 writeb(bin2bcd(tm->tm_hour), ioaddr + RTC_HOURS);
80 writeb(bin2bcd(tm->tm_min), ioaddr + RTC_MINUTES);
81 writeb(bin2bcd(tm->tm_sec) & RTC_SECONDS_MASK, ioaddr + RTC_SECONDS);
Atsushi Nemoto5ec3e4b2006-06-25 05:48:29 -070082
83 /* RTC_CENTURY and RTC_CONTROL share same register */
84 writeb(RTC_WRITE | (century & RTC_CENTURY_MASK), ioaddr + RTC_CENTURY);
85 writeb(century & RTC_CENTURY_MASK, ioaddr + RTC_CONTROL);
86 return 0;
87}
88
89static int ds1742_rtc_read_time(struct device *dev, struct rtc_time *tm)
90{
91 struct platform_device *pdev = to_platform_device(dev);
92 struct rtc_plat_data *pdata = platform_get_drvdata(pdev);
Torsten Ertbjerg Rasmussenf9231a02006-12-06 20:39:41 -080093 void __iomem *ioaddr = pdata->ioaddr_rtc;
Atsushi Nemoto5ec3e4b2006-06-25 05:48:29 -070094 unsigned int year, month, day, hour, minute, second, week;
95 unsigned int century;
96
97 /* give enough time to update RTC in case of continuous read */
98 if (pdata->last_jiffies == jiffies)
99 msleep(1);
100 pdata->last_jiffies = jiffies;
101 writeb(RTC_READ, ioaddr + RTC_CONTROL);
102 second = readb(ioaddr + RTC_SECONDS) & RTC_SECONDS_MASK;
103 minute = readb(ioaddr + RTC_MINUTES);
104 hour = readb(ioaddr + RTC_HOURS);
105 day = readb(ioaddr + RTC_DATE);
106 week = readb(ioaddr + RTC_DAY) & RTC_DAY_MASK;
107 month = readb(ioaddr + RTC_MONTH);
108 year = readb(ioaddr + RTC_YEAR);
109 century = readb(ioaddr + RTC_CENTURY) & RTC_CENTURY_MASK;
110 writeb(0, ioaddr + RTC_CONTROL);
Adrian Bunkfe20ba72008-10-18 20:28:41 -0700111 tm->tm_sec = bcd2bin(second);
112 tm->tm_min = bcd2bin(minute);
113 tm->tm_hour = bcd2bin(hour);
114 tm->tm_mday = bcd2bin(day);
115 tm->tm_wday = bcd2bin(week);
116 tm->tm_mon = bcd2bin(month) - 1;
Atsushi Nemoto5ec3e4b2006-06-25 05:48:29 -0700117 /* year is 1900 + tm->tm_year */
Adrian Bunkfe20ba72008-10-18 20:28:41 -0700118 tm->tm_year = bcd2bin(year) + bcd2bin(century) * 100 - 1900;
Atsushi Nemoto5ec3e4b2006-06-25 05:48:29 -0700119
120 if (rtc_valid_tm(tm) < 0) {
121 dev_err(dev, "retrieved date/time is not valid.\n");
122 rtc_time_to_tm(0, tm);
123 }
124 return 0;
125}
126
David Brownellff8371a2006-09-30 23:28:17 -0700127static const struct rtc_class_ops ds1742_rtc_ops = {
Atsushi Nemoto5ec3e4b2006-06-25 05:48:29 -0700128 .read_time = ds1742_rtc_read_time,
129 .set_time = ds1742_rtc_set_time,
130};
131
Chris Wright2c3c8be2010-05-12 18:28:57 -0700132static ssize_t ds1742_nvram_read(struct file *filp, struct kobject *kobj,
Zhang Rui91a69022007-06-09 13:57:22 +0800133 struct bin_attribute *bin_attr,
134 char *buf, loff_t pos, size_t size)
Atsushi Nemoto5ec3e4b2006-06-25 05:48:29 -0700135{
Atsushi Nemoto50e49be2009-12-15 16:46:04 -0800136 struct device *dev = container_of(kobj, struct device, kobj);
137 struct platform_device *pdev = to_platform_device(dev);
Atsushi Nemoto5ec3e4b2006-06-25 05:48:29 -0700138 struct rtc_plat_data *pdata = platform_get_drvdata(pdev);
Torsten Ertbjerg Rasmussenf9231a02006-12-06 20:39:41 -0800139 void __iomem *ioaddr = pdata->ioaddr_nvram;
Atsushi Nemoto5ec3e4b2006-06-25 05:48:29 -0700140 ssize_t count;
141
Torsten Ertbjerg Rasmussenf9231a02006-12-06 20:39:41 -0800142 for (count = 0; size > 0 && pos < pdata->size_nvram; count++, size--)
Atsushi Nemoto5ec3e4b2006-06-25 05:48:29 -0700143 *buf++ = readb(ioaddr + pos++);
144 return count;
145}
146
Chris Wright2c3c8be2010-05-12 18:28:57 -0700147static ssize_t ds1742_nvram_write(struct file *filp, struct kobject *kobj,
Zhang Rui91a69022007-06-09 13:57:22 +0800148 struct bin_attribute *bin_attr,
149 char *buf, loff_t pos, size_t size)
Atsushi Nemoto5ec3e4b2006-06-25 05:48:29 -0700150{
Atsushi Nemoto50e49be2009-12-15 16:46:04 -0800151 struct device *dev = container_of(kobj, struct device, kobj);
152 struct platform_device *pdev = to_platform_device(dev);
Atsushi Nemoto5ec3e4b2006-06-25 05:48:29 -0700153 struct rtc_plat_data *pdata = platform_get_drvdata(pdev);
Torsten Ertbjerg Rasmussenf9231a02006-12-06 20:39:41 -0800154 void __iomem *ioaddr = pdata->ioaddr_nvram;
Atsushi Nemoto5ec3e4b2006-06-25 05:48:29 -0700155 ssize_t count;
156
Torsten Ertbjerg Rasmussenf9231a02006-12-06 20:39:41 -0800157 for (count = 0; size > 0 && pos < pdata->size_nvram; count++, size--)
Atsushi Nemoto5ec3e4b2006-06-25 05:48:29 -0700158 writeb(*buf++, ioaddr + pos++);
159 return count;
160}
161
Greg Kroah-Hartman5a167f42012-12-21 13:09:38 -0800162static int ds1742_rtc_probe(struct platform_device *pdev)
Atsushi Nemoto5ec3e4b2006-06-25 05:48:29 -0700163{
164 struct rtc_device *rtc;
165 struct resource *res;
166 unsigned int cen, sec;
Atsushi Nemotoac18eb62009-12-15 16:46:02 -0800167 struct rtc_plat_data *pdata;
168 void __iomem *ioaddr;
Atsushi Nemoto5ec3e4b2006-06-25 05:48:29 -0700169 int ret = 0;
170
171 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
172 if (!res)
173 return -ENODEV;
Atsushi Nemotoac18eb62009-12-15 16:46:02 -0800174 pdata = devm_kzalloc(&pdev->dev, sizeof(*pdata), GFP_KERNEL);
Atsushi Nemoto5ec3e4b2006-06-25 05:48:29 -0700175 if (!pdata)
176 return -ENOMEM;
Joe Perches28f65c112011-06-09 09:13:32 -0700177 pdata->size = resource_size(res);
Atsushi Nemotoac18eb62009-12-15 16:46:02 -0800178 if (!devm_request_mem_region(&pdev->dev, res->start, pdata->size,
179 pdev->name))
180 return -EBUSY;
181 ioaddr = devm_ioremap(&pdev->dev, res->start, pdata->size);
182 if (!ioaddr)
183 return -ENOMEM;
184
Torsten Ertbjerg Rasmussenf9231a02006-12-06 20:39:41 -0800185 pdata->ioaddr_nvram = ioaddr;
186 pdata->size_nvram = pdata->size - RTC_SIZE;
187 pdata->ioaddr_rtc = ioaddr + pdata->size_nvram;
Atsushi Nemoto5ec3e4b2006-06-25 05:48:29 -0700188
Wolfram Sangf9373312010-03-15 01:29:41 +0100189 sysfs_bin_attr_init(&pdata->nvram_attr);
Torsten Ertbjerg Rasmussen3a729702009-06-17 16:26:07 -0700190 pdata->nvram_attr.attr.name = "nvram";
191 pdata->nvram_attr.attr.mode = S_IRUGO | S_IWUSR;
192 pdata->nvram_attr.read = ds1742_nvram_read;
193 pdata->nvram_attr.write = ds1742_nvram_write;
194 pdata->nvram_attr.size = pdata->size_nvram;
195
Atsushi Nemoto5ec3e4b2006-06-25 05:48:29 -0700196 /* turn RTC on if it was not on */
Torsten Ertbjerg Rasmussenf9231a02006-12-06 20:39:41 -0800197 ioaddr = pdata->ioaddr_rtc;
Atsushi Nemoto5ec3e4b2006-06-25 05:48:29 -0700198 sec = readb(ioaddr + RTC_SECONDS);
199 if (sec & RTC_STOP) {
200 sec &= RTC_SECONDS_MASK;
201 cen = readb(ioaddr + RTC_CENTURY) & RTC_CENTURY_MASK;
202 writeb(RTC_WRITE, ioaddr + RTC_CONTROL);
203 writeb(sec, ioaddr + RTC_SECONDS);
204 writeb(cen & RTC_CENTURY_MASK, ioaddr + RTC_CONTROL);
205 }
Atsushi Nemoto391b1fe2006-09-30 23:28:18 -0700206 if (!(readb(ioaddr + RTC_DAY) & RTC_BATT_FLAG))
Atsushi Nemoto5ec3e4b2006-06-25 05:48:29 -0700207 dev_warn(&pdev->dev, "voltage-low detected.\n");
208
Atsushi Nemoto5ec3e4b2006-06-25 05:48:29 -0700209 pdata->last_jiffies = jiffies;
210 platform_set_drvdata(pdev, pdata);
Atsushi Nemotoac18eb62009-12-15 16:46:02 -0800211 rtc = rtc_device_register(pdev->name, &pdev->dev,
212 &ds1742_rtc_ops, THIS_MODULE);
213 if (IS_ERR(rtc))
214 return PTR_ERR(rtc);
215 pdata->rtc = rtc;
Torsten Ertbjerg Rasmussen3a729702009-06-17 16:26:07 -0700216
217 ret = sysfs_create_bin_file(&pdev->dev.kobj, &pdata->nvram_attr);
218 if (ret) {
219 dev_err(&pdev->dev, "creating nvram file in sysfs failed\n");
Atsushi Nemotoac18eb62009-12-15 16:46:02 -0800220 rtc_device_unregister(rtc);
Torsten Ertbjerg Rasmussen3a729702009-06-17 16:26:07 -0700221 }
Atsushi Nemoto5ec3e4b2006-06-25 05:48:29 -0700222 return ret;
223}
224
Greg Kroah-Hartman5a167f42012-12-21 13:09:38 -0800225static int ds1742_rtc_remove(struct platform_device *pdev)
Atsushi Nemoto5ec3e4b2006-06-25 05:48:29 -0700226{
227 struct rtc_plat_data *pdata = platform_get_drvdata(pdev);
228
Torsten Ertbjerg Rasmussen3a729702009-06-17 16:26:07 -0700229 sysfs_remove_bin_file(&pdev->dev.kobj, &pdata->nvram_attr);
Atsushi Nemoto5ec3e4b2006-06-25 05:48:29 -0700230 rtc_device_unregister(pdata->rtc);
Atsushi Nemoto5ec3e4b2006-06-25 05:48:29 -0700231 return 0;
232}
233
234static struct platform_driver ds1742_rtc_driver = {
235 .probe = ds1742_rtc_probe,
Greg Kroah-Hartman5a167f42012-12-21 13:09:38 -0800236 .remove = ds1742_rtc_remove,
Atsushi Nemoto5ec3e4b2006-06-25 05:48:29 -0700237 .driver = {
Atsushi Nemotoa95e23a2007-10-16 01:28:18 -0700238 .name = "rtc-ds1742",
Atsushi Nemoto5ec3e4b2006-06-25 05:48:29 -0700239 .owner = THIS_MODULE,
240 },
241};
242
Axel Lin0c4eae62012-01-10 15:10:48 -0800243module_platform_driver(ds1742_rtc_driver);
Atsushi Nemoto5ec3e4b2006-06-25 05:48:29 -0700244
245MODULE_AUTHOR("Atsushi Nemoto <anemo@mba.ocn.ne.jp>");
246MODULE_DESCRIPTION("Dallas DS1742 RTC driver");
247MODULE_LICENSE("GPL");
248MODULE_VERSION(DRV_VERSION);
Kay Sieversad28a072008-04-10 21:29:25 -0700249MODULE_ALIAS("platform:rtc-ds1742");