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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>
Atsushi Nemoto5ec3e4b2006-06-25 05:48:29 -070016#include <linux/kernel.h>
Tejun Heo5a0e3ad2010-03-24 17:04:11 +090017#include <linux/gfp.h>
Atsushi Nemoto5ec3e4b2006-06-25 05:48:29 -070018#include <linux/delay.h>
19#include <linux/jiffies.h>
20#include <linux/rtc.h>
Alexander Shiyan663b3522014-01-23 15:55:06 -080021#include <linux/of.h>
22#include <linux/of_device.h>
Atsushi Nemoto5ec3e4b2006-06-25 05:48:29 -070023#include <linux/platform_device.h>
24#include <linux/io.h>
Paul Gortmaker21138522011-05-27 09:57:25 -040025#include <linux/module.h>
Atsushi Nemoto5ec3e4b2006-06-25 05:48:29 -070026
Atsushi Nemotoac18eb62009-12-15 16:46:02 -080027#define DRV_VERSION "0.4"
Atsushi Nemoto5ec3e4b2006-06-25 05:48:29 -070028
Torsten Ertbjerg Rasmussenf9231a02006-12-06 20:39:41 -080029#define RTC_SIZE 8
Atsushi Nemoto5ec3e4b2006-06-25 05:48:29 -070030
Torsten Ertbjerg Rasmussenf9231a02006-12-06 20:39:41 -080031#define RTC_CONTROL 0
32#define RTC_CENTURY 0
33#define RTC_SECONDS 1
34#define RTC_MINUTES 2
35#define RTC_HOURS 3
36#define RTC_DAY 4
37#define RTC_DATE 5
38#define RTC_MONTH 6
39#define RTC_YEAR 7
Atsushi Nemoto5ec3e4b2006-06-25 05:48:29 -070040
41#define RTC_CENTURY_MASK 0x3f
42#define RTC_SECONDS_MASK 0x7f
43#define RTC_DAY_MASK 0x07
44
45/* Bits in the Control/Century register */
46#define RTC_WRITE 0x80
47#define RTC_READ 0x40
48
49/* Bits in the Seconds register */
50#define RTC_STOP 0x80
51
52/* Bits in the Day register */
53#define RTC_BATT_FLAG 0x80
54
55struct rtc_plat_data {
Torsten Ertbjerg Rasmussenf9231a02006-12-06 20:39:41 -080056 void __iomem *ioaddr_nvram;
57 void __iomem *ioaddr_rtc;
58 size_t size_nvram;
Atsushi Nemoto5ec3e4b2006-06-25 05:48:29 -070059 unsigned long last_jiffies;
Torsten Ertbjerg Rasmussen3a729702009-06-17 16:26:07 -070060 struct bin_attribute nvram_attr;
Atsushi Nemoto5ec3e4b2006-06-25 05:48:29 -070061};
62
63static int ds1742_rtc_set_time(struct device *dev, struct rtc_time *tm)
64{
65 struct platform_device *pdev = to_platform_device(dev);
66 struct rtc_plat_data *pdata = platform_get_drvdata(pdev);
Torsten Ertbjerg Rasmussenf9231a02006-12-06 20:39:41 -080067 void __iomem *ioaddr = pdata->ioaddr_rtc;
Atsushi Nemoto5ec3e4b2006-06-25 05:48:29 -070068 u8 century;
69
Adrian Bunkfe20ba72008-10-18 20:28:41 -070070 century = bin2bcd((tm->tm_year + 1900) / 100);
Atsushi Nemoto5ec3e4b2006-06-25 05:48:29 -070071
72 writeb(RTC_WRITE, ioaddr + RTC_CONTROL);
73
Adrian Bunkfe20ba72008-10-18 20:28:41 -070074 writeb(bin2bcd(tm->tm_year % 100), ioaddr + RTC_YEAR);
75 writeb(bin2bcd(tm->tm_mon + 1), ioaddr + RTC_MONTH);
76 writeb(bin2bcd(tm->tm_wday) & RTC_DAY_MASK, ioaddr + RTC_DAY);
77 writeb(bin2bcd(tm->tm_mday), ioaddr + RTC_DATE);
78 writeb(bin2bcd(tm->tm_hour), ioaddr + RTC_HOURS);
79 writeb(bin2bcd(tm->tm_min), ioaddr + RTC_MINUTES);
80 writeb(bin2bcd(tm->tm_sec) & RTC_SECONDS_MASK, ioaddr + RTC_SECONDS);
Atsushi Nemoto5ec3e4b2006-06-25 05:48:29 -070081
82 /* RTC_CENTURY and RTC_CONTROL share same register */
83 writeb(RTC_WRITE | (century & RTC_CENTURY_MASK), ioaddr + RTC_CENTURY);
84 writeb(century & RTC_CENTURY_MASK, ioaddr + RTC_CONTROL);
85 return 0;
86}
87
88static int ds1742_rtc_read_time(struct device *dev, struct rtc_time *tm)
89{
90 struct platform_device *pdev = to_platform_device(dev);
91 struct rtc_plat_data *pdata = platform_get_drvdata(pdev);
Torsten Ertbjerg Rasmussenf9231a02006-12-06 20:39:41 -080092 void __iomem *ioaddr = pdata->ioaddr_rtc;
Atsushi Nemoto5ec3e4b2006-06-25 05:48:29 -070093 unsigned int year, month, day, hour, minute, second, week;
94 unsigned int century;
95
96 /* give enough time to update RTC in case of continuous read */
97 if (pdata->last_jiffies == jiffies)
98 msleep(1);
99 pdata->last_jiffies = jiffies;
100 writeb(RTC_READ, ioaddr + RTC_CONTROL);
101 second = readb(ioaddr + RTC_SECONDS) & RTC_SECONDS_MASK;
102 minute = readb(ioaddr + RTC_MINUTES);
103 hour = readb(ioaddr + RTC_HOURS);
104 day = readb(ioaddr + RTC_DATE);
105 week = readb(ioaddr + RTC_DAY) & RTC_DAY_MASK;
106 month = readb(ioaddr + RTC_MONTH);
107 year = readb(ioaddr + RTC_YEAR);
108 century = readb(ioaddr + RTC_CENTURY) & RTC_CENTURY_MASK;
109 writeb(0, ioaddr + RTC_CONTROL);
Adrian Bunkfe20ba72008-10-18 20:28:41 -0700110 tm->tm_sec = bcd2bin(second);
111 tm->tm_min = bcd2bin(minute);
112 tm->tm_hour = bcd2bin(hour);
113 tm->tm_mday = bcd2bin(day);
114 tm->tm_wday = bcd2bin(week);
115 tm->tm_mon = bcd2bin(month) - 1;
Atsushi Nemoto5ec3e4b2006-06-25 05:48:29 -0700116 /* year is 1900 + tm->tm_year */
Adrian Bunkfe20ba72008-10-18 20:28:41 -0700117 tm->tm_year = bcd2bin(year) + bcd2bin(century) * 100 - 1900;
Atsushi Nemoto5ec3e4b2006-06-25 05:48:29 -0700118
Alexander Shiyan1735be42013-09-11 14:24:26 -0700119 return rtc_valid_tm(tm);
Atsushi Nemoto5ec3e4b2006-06-25 05:48:29 -0700120}
121
David Brownellff8371a2006-09-30 23:28:17 -0700122static const struct rtc_class_ops ds1742_rtc_ops = {
Atsushi Nemoto5ec3e4b2006-06-25 05:48:29 -0700123 .read_time = ds1742_rtc_read_time,
124 .set_time = ds1742_rtc_set_time,
125};
126
Chris Wright2c3c8be2010-05-12 18:28:57 -0700127static ssize_t ds1742_nvram_read(struct file *filp, struct kobject *kobj,
Zhang Rui91a69022007-06-09 13:57:22 +0800128 struct bin_attribute *bin_attr,
129 char *buf, loff_t pos, size_t size)
Atsushi Nemoto5ec3e4b2006-06-25 05:48:29 -0700130{
Atsushi Nemoto50e49be2009-12-15 16:46:04 -0800131 struct device *dev = container_of(kobj, struct device, kobj);
132 struct platform_device *pdev = to_platform_device(dev);
Atsushi Nemoto5ec3e4b2006-06-25 05:48:29 -0700133 struct rtc_plat_data *pdata = platform_get_drvdata(pdev);
Torsten Ertbjerg Rasmussenf9231a02006-12-06 20:39:41 -0800134 void __iomem *ioaddr = pdata->ioaddr_nvram;
Atsushi Nemoto5ec3e4b2006-06-25 05:48:29 -0700135 ssize_t count;
136
Torsten Ertbjerg Rasmussenf9231a02006-12-06 20:39:41 -0800137 for (count = 0; size > 0 && pos < pdata->size_nvram; count++, size--)
Atsushi Nemoto5ec3e4b2006-06-25 05:48:29 -0700138 *buf++ = readb(ioaddr + pos++);
139 return count;
140}
141
Chris Wright2c3c8be2010-05-12 18:28:57 -0700142static ssize_t ds1742_nvram_write(struct file *filp, struct kobject *kobj,
Zhang Rui91a69022007-06-09 13:57:22 +0800143 struct bin_attribute *bin_attr,
144 char *buf, loff_t pos, size_t size)
Atsushi Nemoto5ec3e4b2006-06-25 05:48:29 -0700145{
Atsushi Nemoto50e49be2009-12-15 16:46:04 -0800146 struct device *dev = container_of(kobj, struct device, kobj);
147 struct platform_device *pdev = to_platform_device(dev);
Atsushi Nemoto5ec3e4b2006-06-25 05:48:29 -0700148 struct rtc_plat_data *pdata = platform_get_drvdata(pdev);
Torsten Ertbjerg Rasmussenf9231a02006-12-06 20:39:41 -0800149 void __iomem *ioaddr = pdata->ioaddr_nvram;
Atsushi Nemoto5ec3e4b2006-06-25 05:48:29 -0700150 ssize_t count;
151
Torsten Ertbjerg Rasmussenf9231a02006-12-06 20:39:41 -0800152 for (count = 0; size > 0 && pos < pdata->size_nvram; count++, size--)
Atsushi Nemoto5ec3e4b2006-06-25 05:48:29 -0700153 writeb(*buf++, ioaddr + pos++);
154 return count;
155}
156
Greg Kroah-Hartman5a167f42012-12-21 13:09:38 -0800157static int ds1742_rtc_probe(struct platform_device *pdev)
Atsushi Nemoto5ec3e4b2006-06-25 05:48:29 -0700158{
159 struct rtc_device *rtc;
160 struct resource *res;
161 unsigned int cen, sec;
Atsushi Nemotoac18eb62009-12-15 16:46:02 -0800162 struct rtc_plat_data *pdata;
163 void __iomem *ioaddr;
Atsushi Nemoto5ec3e4b2006-06-25 05:48:29 -0700164 int ret = 0;
165
Atsushi Nemotoac18eb62009-12-15 16:46:02 -0800166 pdata = devm_kzalloc(&pdev->dev, sizeof(*pdata), GFP_KERNEL);
Atsushi Nemoto5ec3e4b2006-06-25 05:48:29 -0700167 if (!pdata)
168 return -ENOMEM;
Alexander Shiyan25e28182013-09-11 14:24:24 -0700169
170 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
171 ioaddr = devm_ioremap_resource(&pdev->dev, res);
172 if (IS_ERR(ioaddr))
173 return PTR_ERR(ioaddr);
Atsushi Nemotoac18eb62009-12-15 16:46:02 -0800174
Torsten Ertbjerg Rasmussenf9231a02006-12-06 20:39:41 -0800175 pdata->ioaddr_nvram = ioaddr;
Alexander Shiyan25e28182013-09-11 14:24:24 -0700176 pdata->size_nvram = resource_size(res) - RTC_SIZE;
Torsten Ertbjerg Rasmussenf9231a02006-12-06 20:39:41 -0800177 pdata->ioaddr_rtc = ioaddr + pdata->size_nvram;
Atsushi Nemoto5ec3e4b2006-06-25 05:48:29 -0700178
Wolfram Sangf9373312010-03-15 01:29:41 +0100179 sysfs_bin_attr_init(&pdata->nvram_attr);
Torsten Ertbjerg Rasmussen3a729702009-06-17 16:26:07 -0700180 pdata->nvram_attr.attr.name = "nvram";
181 pdata->nvram_attr.attr.mode = S_IRUGO | S_IWUSR;
182 pdata->nvram_attr.read = ds1742_nvram_read;
183 pdata->nvram_attr.write = ds1742_nvram_write;
184 pdata->nvram_attr.size = pdata->size_nvram;
185
Atsushi Nemoto5ec3e4b2006-06-25 05:48:29 -0700186 /* turn RTC on if it was not on */
Torsten Ertbjerg Rasmussenf9231a02006-12-06 20:39:41 -0800187 ioaddr = pdata->ioaddr_rtc;
Atsushi Nemoto5ec3e4b2006-06-25 05:48:29 -0700188 sec = readb(ioaddr + RTC_SECONDS);
189 if (sec & RTC_STOP) {
190 sec &= RTC_SECONDS_MASK;
191 cen = readb(ioaddr + RTC_CENTURY) & RTC_CENTURY_MASK;
192 writeb(RTC_WRITE, ioaddr + RTC_CONTROL);
193 writeb(sec, ioaddr + RTC_SECONDS);
194 writeb(cen & RTC_CENTURY_MASK, ioaddr + RTC_CONTROL);
195 }
Atsushi Nemoto391b1fe2006-09-30 23:28:18 -0700196 if (!(readb(ioaddr + RTC_DAY) & RTC_BATT_FLAG))
Atsushi Nemoto5ec3e4b2006-06-25 05:48:29 -0700197 dev_warn(&pdev->dev, "voltage-low detected.\n");
198
Atsushi Nemoto5ec3e4b2006-06-25 05:48:29 -0700199 pdata->last_jiffies = jiffies;
200 platform_set_drvdata(pdev, pdata);
Jingoo Hanf7cfdea2013-04-29 16:19:01 -0700201 rtc = devm_rtc_device_register(&pdev->dev, pdev->name,
Atsushi Nemotoac18eb62009-12-15 16:46:02 -0800202 &ds1742_rtc_ops, THIS_MODULE);
203 if (IS_ERR(rtc))
204 return PTR_ERR(rtc);
Torsten Ertbjerg Rasmussen3a729702009-06-17 16:26:07 -0700205
206 ret = sysfs_create_bin_file(&pdev->dev.kobj, &pdata->nvram_attr);
Alessandro Zummo4071ea22014-04-03 14:49:36 -0700207 if (ret)
208 dev_err(&pdev->dev, "Unable to create sysfs entry: %s\n",
209 pdata->nvram_attr.attr.name);
Jingoo Hanf7cfdea2013-04-29 16:19:01 -0700210
Alessandro Zummo4071ea22014-04-03 14:49:36 -0700211 return 0;
Atsushi Nemoto5ec3e4b2006-06-25 05:48:29 -0700212}
213
Greg Kroah-Hartman5a167f42012-12-21 13:09:38 -0800214static int ds1742_rtc_remove(struct platform_device *pdev)
Atsushi Nemoto5ec3e4b2006-06-25 05:48:29 -0700215{
216 struct rtc_plat_data *pdata = platform_get_drvdata(pdev);
217
Torsten Ertbjerg Rasmussen3a729702009-06-17 16:26:07 -0700218 sysfs_remove_bin_file(&pdev->dev.kobj, &pdata->nvram_attr);
Atsushi Nemoto5ec3e4b2006-06-25 05:48:29 -0700219 return 0;
220}
221
Jingoo Han9d203572014-06-06 14:35:54 -0700222static const struct of_device_id __maybe_unused ds1742_rtc_of_match[] = {
Alexander Shiyan663b3522014-01-23 15:55:06 -0800223 { .compatible = "maxim,ds1742", },
224 { }
225};
226MODULE_DEVICE_TABLE(of, ds1742_rtc_of_match);
227
Atsushi Nemoto5ec3e4b2006-06-25 05:48:29 -0700228static struct platform_driver ds1742_rtc_driver = {
229 .probe = ds1742_rtc_probe,
Greg Kroah-Hartman5a167f42012-12-21 13:09:38 -0800230 .remove = ds1742_rtc_remove,
Atsushi Nemoto5ec3e4b2006-06-25 05:48:29 -0700231 .driver = {
Atsushi Nemotoa95e23a2007-10-16 01:28:18 -0700232 .name = "rtc-ds1742",
Atsushi Nemoto5ec3e4b2006-06-25 05:48:29 -0700233 .owner = THIS_MODULE,
Alexander Shiyan3710f592014-08-08 14:20:07 -0700234 .of_match_table = of_match_ptr(ds1742_rtc_of_match),
Atsushi Nemoto5ec3e4b2006-06-25 05:48:29 -0700235 },
236};
237
Axel Lin0c4eae62012-01-10 15:10:48 -0800238module_platform_driver(ds1742_rtc_driver);
Atsushi Nemoto5ec3e4b2006-06-25 05:48:29 -0700239
240MODULE_AUTHOR("Atsushi Nemoto <anemo@mba.ocn.ne.jp>");
241MODULE_DESCRIPTION("Dallas DS1742 RTC driver");
242MODULE_LICENSE("GPL");
243MODULE_VERSION(DRV_VERSION);
Kay Sieversad28a072008-04-10 21:29:25 -0700244MODULE_ALIAS("platform:rtc-ds1742");