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5ec3e4b7 AN |
1 | /* |
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. | |
f9231a0c TER |
9 | * |
10 | * Copyright (C) 2006 Torsten Ertbjerg Rasmussen <tr@newtec.dk> | |
11 | * - nvram size determined from resource | |
12 | * - this ds1742 driver now supports ds1743. | |
5ec3e4b7 AN |
13 | */ |
14 | ||
15 | #include <linux/bcd.h> | |
16 | #include <linux/init.h> | |
17 | #include <linux/kernel.h> | |
5a0e3ad6 | 18 | #include <linux/gfp.h> |
5ec3e4b7 AN |
19 | #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> | |
2113852b | 24 | #include <linux/module.h> |
5ec3e4b7 | 25 | |
ac18eb62 | 26 | #define DRV_VERSION "0.4" |
5ec3e4b7 | 27 | |
f9231a0c | 28 | #define RTC_SIZE 8 |
5ec3e4b7 | 29 | |
f9231a0c TER |
30 | #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 | |
5ec3e4b7 AN |
39 | |
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 | ||
54 | struct rtc_plat_data { | |
55 | struct rtc_device *rtc; | |
f9231a0c TER |
56 | void __iomem *ioaddr_nvram; |
57 | void __iomem *ioaddr_rtc; | |
58 | size_t size_nvram; | |
59 | size_t size; | |
5ec3e4b7 | 60 | unsigned long last_jiffies; |
3a729700 | 61 | struct bin_attribute nvram_attr; |
5ec3e4b7 AN |
62 | }; |
63 | ||
64 | static 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); | |
f9231a0c | 68 | void __iomem *ioaddr = pdata->ioaddr_rtc; |
5ec3e4b7 AN |
69 | u8 century; |
70 | ||
fe20ba70 | 71 | century = bin2bcd((tm->tm_year + 1900) / 100); |
5ec3e4b7 AN |
72 | |
73 | writeb(RTC_WRITE, ioaddr + RTC_CONTROL); | |
74 | ||
fe20ba70 AB |
75 | 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); | |
5ec3e4b7 AN |
82 | |
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 | ||
89 | static 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); | |
f9231a0c | 93 | void __iomem *ioaddr = pdata->ioaddr_rtc; |
5ec3e4b7 AN |
94 | 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); | |
fe20ba70 AB |
111 | 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; | |
5ec3e4b7 | 117 | /* year is 1900 + tm->tm_year */ |
fe20ba70 | 118 | tm->tm_year = bcd2bin(year) + bcd2bin(century) * 100 - 1900; |
5ec3e4b7 AN |
119 | |
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 | ||
ff8371ac | 127 | static const struct rtc_class_ops ds1742_rtc_ops = { |
5ec3e4b7 AN |
128 | .read_time = ds1742_rtc_read_time, |
129 | .set_time = ds1742_rtc_set_time, | |
130 | }; | |
131 | ||
2c3c8bea | 132 | static ssize_t ds1742_nvram_read(struct file *filp, struct kobject *kobj, |
91a69029 ZR |
133 | struct bin_attribute *bin_attr, |
134 | char *buf, loff_t pos, size_t size) | |
5ec3e4b7 | 135 | { |
50e49bee AN |
136 | struct device *dev = container_of(kobj, struct device, kobj); |
137 | struct platform_device *pdev = to_platform_device(dev); | |
5ec3e4b7 | 138 | struct rtc_plat_data *pdata = platform_get_drvdata(pdev); |
f9231a0c | 139 | void __iomem *ioaddr = pdata->ioaddr_nvram; |
5ec3e4b7 AN |
140 | ssize_t count; |
141 | ||
f9231a0c | 142 | for (count = 0; size > 0 && pos < pdata->size_nvram; count++, size--) |
5ec3e4b7 AN |
143 | *buf++ = readb(ioaddr + pos++); |
144 | return count; | |
145 | } | |
146 | ||
2c3c8bea | 147 | static ssize_t ds1742_nvram_write(struct file *filp, struct kobject *kobj, |
91a69029 ZR |
148 | struct bin_attribute *bin_attr, |
149 | char *buf, loff_t pos, size_t size) | |
5ec3e4b7 | 150 | { |
50e49bee AN |
151 | struct device *dev = container_of(kobj, struct device, kobj); |
152 | struct platform_device *pdev = to_platform_device(dev); | |
5ec3e4b7 | 153 | struct rtc_plat_data *pdata = platform_get_drvdata(pdev); |
f9231a0c | 154 | void __iomem *ioaddr = pdata->ioaddr_nvram; |
5ec3e4b7 AN |
155 | ssize_t count; |
156 | ||
f9231a0c | 157 | for (count = 0; size > 0 && pos < pdata->size_nvram; count++, size--) |
5ec3e4b7 AN |
158 | writeb(*buf++, ioaddr + pos++); |
159 | return count; | |
160 | } | |
161 | ||
5a167f45 | 162 | static int ds1742_rtc_probe(struct platform_device *pdev) |
5ec3e4b7 AN |
163 | { |
164 | struct rtc_device *rtc; | |
165 | struct resource *res; | |
166 | unsigned int cen, sec; | |
ac18eb62 AN |
167 | struct rtc_plat_data *pdata; |
168 | void __iomem *ioaddr; | |
5ec3e4b7 AN |
169 | int ret = 0; |
170 | ||
171 | res = platform_get_resource(pdev, IORESOURCE_MEM, 0); | |
172 | if (!res) | |
173 | return -ENODEV; | |
ac18eb62 | 174 | pdata = devm_kzalloc(&pdev->dev, sizeof(*pdata), GFP_KERNEL); |
5ec3e4b7 AN |
175 | if (!pdata) |
176 | return -ENOMEM; | |
28f65c11 | 177 | pdata->size = resource_size(res); |
ac18eb62 AN |
178 | 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 | ||
f9231a0c TER |
185 | pdata->ioaddr_nvram = ioaddr; |
186 | pdata->size_nvram = pdata->size - RTC_SIZE; | |
187 | pdata->ioaddr_rtc = ioaddr + pdata->size_nvram; | |
5ec3e4b7 | 188 | |
f937331b | 189 | sysfs_bin_attr_init(&pdata->nvram_attr); |
3a729700 TER |
190 | 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 | ||
5ec3e4b7 | 196 | /* turn RTC on if it was not on */ |
f9231a0c | 197 | ioaddr = pdata->ioaddr_rtc; |
5ec3e4b7 AN |
198 | 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 | } | |
391b1fe6 | 206 | if (!(readb(ioaddr + RTC_DAY) & RTC_BATT_FLAG)) |
5ec3e4b7 AN |
207 | dev_warn(&pdev->dev, "voltage-low detected.\n"); |
208 | ||
ac18eb62 AN |
209 | pdata->last_jiffies = jiffies; |
210 | platform_set_drvdata(pdev, pdata); | |
5ec3e4b7 AN |
211 | rtc = rtc_device_register(pdev->name, &pdev->dev, |
212 | &ds1742_rtc_ops, THIS_MODULE); | |
ac18eb62 AN |
213 | if (IS_ERR(rtc)) |
214 | return PTR_ERR(rtc); | |
5ec3e4b7 | 215 | pdata->rtc = rtc; |
3a729700 TER |
216 | |
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"); | |
ac18eb62 | 220 | rtc_device_unregister(rtc); |
3a729700 | 221 | } |
5ec3e4b7 AN |
222 | return ret; |
223 | } | |
224 | ||
5a167f45 | 225 | static int ds1742_rtc_remove(struct platform_device *pdev) |
5ec3e4b7 AN |
226 | { |
227 | struct rtc_plat_data *pdata = platform_get_drvdata(pdev); | |
228 | ||
3a729700 | 229 | sysfs_remove_bin_file(&pdev->dev.kobj, &pdata->nvram_attr); |
5ec3e4b7 | 230 | rtc_device_unregister(pdata->rtc); |
5ec3e4b7 AN |
231 | return 0; |
232 | } | |
233 | ||
234 | static struct platform_driver ds1742_rtc_driver = { | |
235 | .probe = ds1742_rtc_probe, | |
5a167f45 | 236 | .remove = ds1742_rtc_remove, |
5ec3e4b7 | 237 | .driver = { |
a95e23a2 | 238 | .name = "rtc-ds1742", |
5ec3e4b7 AN |
239 | .owner = THIS_MODULE, |
240 | }, | |
241 | }; | |
242 | ||
0c4eae66 | 243 | module_platform_driver(ds1742_rtc_driver); |
5ec3e4b7 AN |
244 | |
245 | MODULE_AUTHOR("Atsushi Nemoto <anemo@mba.ocn.ne.jp>"); | |
246 | MODULE_DESCRIPTION("Dallas DS1742 RTC driver"); | |
247 | MODULE_LICENSE("GPL"); | |
248 | MODULE_VERSION(DRV_VERSION); | |
ad28a07b | 249 | MODULE_ALIAS("platform:rtc-ds1742"); |