Commit | Line | Data |
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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> | |
18 | #include <linux/delay.h> | |
19 | #include <linux/jiffies.h> | |
20 | #include <linux/rtc.h> | |
21 | #include <linux/platform_device.h> | |
22 | #include <linux/io.h> | |
23 | ||
f9231a0c | 24 | #define DRV_VERSION "0.3" |
5ec3e4b7 | 25 | |
f9231a0c | 26 | #define RTC_SIZE 8 |
5ec3e4b7 | 27 | |
f9231a0c TER |
28 | #define RTC_CONTROL 0 |
29 | #define RTC_CENTURY 0 | |
30 | #define RTC_SECONDS 1 | |
31 | #define RTC_MINUTES 2 | |
32 | #define RTC_HOURS 3 | |
33 | #define RTC_DAY 4 | |
34 | #define RTC_DATE 5 | |
35 | #define RTC_MONTH 6 | |
36 | #define RTC_YEAR 7 | |
5ec3e4b7 AN |
37 | |
38 | #define RTC_CENTURY_MASK 0x3f | |
39 | #define RTC_SECONDS_MASK 0x7f | |
40 | #define RTC_DAY_MASK 0x07 | |
41 | ||
42 | /* Bits in the Control/Century register */ | |
43 | #define RTC_WRITE 0x80 | |
44 | #define RTC_READ 0x40 | |
45 | ||
46 | /* Bits in the Seconds register */ | |
47 | #define RTC_STOP 0x80 | |
48 | ||
49 | /* Bits in the Day register */ | |
50 | #define RTC_BATT_FLAG 0x80 | |
51 | ||
52 | struct rtc_plat_data { | |
53 | struct rtc_device *rtc; | |
f9231a0c TER |
54 | void __iomem *ioaddr_nvram; |
55 | void __iomem *ioaddr_rtc; | |
56 | size_t size_nvram; | |
57 | size_t size; | |
2e3e31c0 | 58 | resource_size_t baseaddr; |
5ec3e4b7 AN |
59 | unsigned long last_jiffies; |
60 | }; | |
61 | ||
62 | static int ds1742_rtc_set_time(struct device *dev, struct rtc_time *tm) | |
63 | { | |
64 | struct platform_device *pdev = to_platform_device(dev); | |
65 | struct rtc_plat_data *pdata = platform_get_drvdata(pdev); | |
f9231a0c | 66 | void __iomem *ioaddr = pdata->ioaddr_rtc; |
5ec3e4b7 AN |
67 | u8 century; |
68 | ||
69 | century = BIN2BCD((tm->tm_year + 1900) / 100); | |
70 | ||
71 | writeb(RTC_WRITE, ioaddr + RTC_CONTROL); | |
72 | ||
73 | writeb(BIN2BCD(tm->tm_year % 100), ioaddr + RTC_YEAR); | |
74 | writeb(BIN2BCD(tm->tm_mon + 1), ioaddr + RTC_MONTH); | |
75 | writeb(BIN2BCD(tm->tm_wday) & RTC_DAY_MASK, ioaddr + RTC_DAY); | |
76 | writeb(BIN2BCD(tm->tm_mday), ioaddr + RTC_DATE); | |
77 | writeb(BIN2BCD(tm->tm_hour), ioaddr + RTC_HOURS); | |
78 | writeb(BIN2BCD(tm->tm_min), ioaddr + RTC_MINUTES); | |
79 | writeb(BIN2BCD(tm->tm_sec) & RTC_SECONDS_MASK, ioaddr + RTC_SECONDS); | |
80 | ||
81 | /* RTC_CENTURY and RTC_CONTROL share same register */ | |
82 | writeb(RTC_WRITE | (century & RTC_CENTURY_MASK), ioaddr + RTC_CENTURY); | |
83 | writeb(century & RTC_CENTURY_MASK, ioaddr + RTC_CONTROL); | |
84 | return 0; | |
85 | } | |
86 | ||
87 | static int ds1742_rtc_read_time(struct device *dev, struct rtc_time *tm) | |
88 | { | |
89 | struct platform_device *pdev = to_platform_device(dev); | |
90 | struct rtc_plat_data *pdata = platform_get_drvdata(pdev); | |
f9231a0c | 91 | void __iomem *ioaddr = pdata->ioaddr_rtc; |
5ec3e4b7 AN |
92 | unsigned int year, month, day, hour, minute, second, week; |
93 | unsigned int century; | |
94 | ||
95 | /* give enough time to update RTC in case of continuous read */ | |
96 | if (pdata->last_jiffies == jiffies) | |
97 | msleep(1); | |
98 | pdata->last_jiffies = jiffies; | |
99 | writeb(RTC_READ, ioaddr + RTC_CONTROL); | |
100 | second = readb(ioaddr + RTC_SECONDS) & RTC_SECONDS_MASK; | |
101 | minute = readb(ioaddr + RTC_MINUTES); | |
102 | hour = readb(ioaddr + RTC_HOURS); | |
103 | day = readb(ioaddr + RTC_DATE); | |
104 | week = readb(ioaddr + RTC_DAY) & RTC_DAY_MASK; | |
105 | month = readb(ioaddr + RTC_MONTH); | |
106 | year = readb(ioaddr + RTC_YEAR); | |
107 | century = readb(ioaddr + RTC_CENTURY) & RTC_CENTURY_MASK; | |
108 | writeb(0, ioaddr + RTC_CONTROL); | |
109 | tm->tm_sec = BCD2BIN(second); | |
110 | tm->tm_min = BCD2BIN(minute); | |
111 | tm->tm_hour = BCD2BIN(hour); | |
112 | tm->tm_mday = BCD2BIN(day); | |
113 | tm->tm_wday = BCD2BIN(week); | |
114 | tm->tm_mon = BCD2BIN(month) - 1; | |
115 | /* year is 1900 + tm->tm_year */ | |
116 | tm->tm_year = BCD2BIN(year) + BCD2BIN(century) * 100 - 1900; | |
117 | ||
118 | if (rtc_valid_tm(tm) < 0) { | |
119 | dev_err(dev, "retrieved date/time is not valid.\n"); | |
120 | rtc_time_to_tm(0, tm); | |
121 | } | |
122 | return 0; | |
123 | } | |
124 | ||
ff8371ac | 125 | static const struct rtc_class_ops ds1742_rtc_ops = { |
5ec3e4b7 AN |
126 | .read_time = ds1742_rtc_read_time, |
127 | .set_time = ds1742_rtc_set_time, | |
128 | }; | |
129 | ||
91a69029 ZR |
130 | static ssize_t ds1742_nvram_read(struct kobject *kobj, |
131 | struct bin_attribute *bin_attr, | |
132 | char *buf, loff_t pos, size_t size) | |
5ec3e4b7 AN |
133 | { |
134 | struct platform_device *pdev = | |
135 | to_platform_device(container_of(kobj, struct device, kobj)); | |
136 | struct rtc_plat_data *pdata = platform_get_drvdata(pdev); | |
f9231a0c | 137 | void __iomem *ioaddr = pdata->ioaddr_nvram; |
5ec3e4b7 AN |
138 | ssize_t count; |
139 | ||
f9231a0c | 140 | for (count = 0; size > 0 && pos < pdata->size_nvram; count++, size--) |
5ec3e4b7 AN |
141 | *buf++ = readb(ioaddr + pos++); |
142 | return count; | |
143 | } | |
144 | ||
91a69029 ZR |
145 | static ssize_t ds1742_nvram_write(struct kobject *kobj, |
146 | struct bin_attribute *bin_attr, | |
147 | char *buf, loff_t pos, size_t size) | |
5ec3e4b7 AN |
148 | { |
149 | struct platform_device *pdev = | |
150 | to_platform_device(container_of(kobj, struct device, kobj)); | |
151 | struct rtc_plat_data *pdata = platform_get_drvdata(pdev); | |
f9231a0c | 152 | void __iomem *ioaddr = pdata->ioaddr_nvram; |
5ec3e4b7 AN |
153 | ssize_t count; |
154 | ||
f9231a0c | 155 | for (count = 0; size > 0 && pos < pdata->size_nvram; count++, size--) |
5ec3e4b7 AN |
156 | writeb(*buf++, ioaddr + pos++); |
157 | return count; | |
158 | } | |
159 | ||
160 | static struct bin_attribute ds1742_nvram_attr = { | |
161 | .attr = { | |
162 | .name = "nvram", | |
a4b1d50e | 163 | .mode = S_IRUGO | S_IWUSR, |
5ec3e4b7 | 164 | }, |
5ec3e4b7 AN |
165 | .read = ds1742_nvram_read, |
166 | .write = ds1742_nvram_write, | |
a4b1d50e DB |
167 | /* REVISIT: size in sysfs won't match actual size... if it's |
168 | * not a constant, each RTC should have its own attribute. | |
169 | */ | |
5ec3e4b7 AN |
170 | }; |
171 | ||
c239122d | 172 | static int __devinit ds1742_rtc_probe(struct platform_device *pdev) |
5ec3e4b7 AN |
173 | { |
174 | struct rtc_device *rtc; | |
175 | struct resource *res; | |
176 | unsigned int cen, sec; | |
177 | struct rtc_plat_data *pdata = NULL; | |
178 | void __iomem *ioaddr = NULL; | |
179 | int ret = 0; | |
180 | ||
181 | res = platform_get_resource(pdev, IORESOURCE_MEM, 0); | |
182 | if (!res) | |
183 | return -ENODEV; | |
184 | pdata = kzalloc(sizeof(*pdata), GFP_KERNEL); | |
185 | if (!pdata) | |
186 | return -ENOMEM; | |
f9231a0c TER |
187 | pdata->size = res->end - res->start + 1; |
188 | if (!request_mem_region(res->start, pdata->size, pdev->name)) { | |
5ec3e4b7 AN |
189 | ret = -EBUSY; |
190 | goto out; | |
191 | } | |
192 | pdata->baseaddr = res->start; | |
f9231a0c | 193 | ioaddr = ioremap(pdata->baseaddr, pdata->size); |
5ec3e4b7 AN |
194 | if (!ioaddr) { |
195 | ret = -ENOMEM; | |
196 | goto out; | |
197 | } | |
f9231a0c TER |
198 | pdata->ioaddr_nvram = ioaddr; |
199 | pdata->size_nvram = pdata->size - RTC_SIZE; | |
200 | pdata->ioaddr_rtc = ioaddr + pdata->size_nvram; | |
5ec3e4b7 AN |
201 | |
202 | /* turn RTC on if it was not on */ | |
f9231a0c | 203 | ioaddr = pdata->ioaddr_rtc; |
5ec3e4b7 AN |
204 | sec = readb(ioaddr + RTC_SECONDS); |
205 | if (sec & RTC_STOP) { | |
206 | sec &= RTC_SECONDS_MASK; | |
207 | cen = readb(ioaddr + RTC_CENTURY) & RTC_CENTURY_MASK; | |
208 | writeb(RTC_WRITE, ioaddr + RTC_CONTROL); | |
209 | writeb(sec, ioaddr + RTC_SECONDS); | |
210 | writeb(cen & RTC_CENTURY_MASK, ioaddr + RTC_CONTROL); | |
211 | } | |
391b1fe6 | 212 | if (!(readb(ioaddr + RTC_DAY) & RTC_BATT_FLAG)) |
5ec3e4b7 AN |
213 | dev_warn(&pdev->dev, "voltage-low detected.\n"); |
214 | ||
215 | rtc = rtc_device_register(pdev->name, &pdev->dev, | |
216 | &ds1742_rtc_ops, THIS_MODULE); | |
217 | if (IS_ERR(rtc)) { | |
218 | ret = PTR_ERR(rtc); | |
219 | goto out; | |
220 | } | |
221 | pdata->rtc = rtc; | |
222 | pdata->last_jiffies = jiffies; | |
223 | platform_set_drvdata(pdev, pdata); | |
f9231a0c TER |
224 | ds1742_nvram_attr.size = max(ds1742_nvram_attr.size, |
225 | pdata->size_nvram); | |
391b1fe6 AN |
226 | ret = sysfs_create_bin_file(&pdev->dev.kobj, &ds1742_nvram_attr); |
227 | if (ret) | |
228 | goto out; | |
5ec3e4b7 AN |
229 | return 0; |
230 | out: | |
391b1fe6 AN |
231 | if (pdata->rtc) |
232 | rtc_device_unregister(pdata->rtc); | |
f9231a0c TER |
233 | if (pdata->ioaddr_nvram) |
234 | iounmap(pdata->ioaddr_nvram); | |
5ec3e4b7 | 235 | if (pdata->baseaddr) |
f9231a0c | 236 | release_mem_region(pdata->baseaddr, pdata->size); |
5ec3e4b7 AN |
237 | kfree(pdata); |
238 | return ret; | |
239 | } | |
240 | ||
241 | static int __devexit ds1742_rtc_remove(struct platform_device *pdev) | |
242 | { | |
243 | struct rtc_plat_data *pdata = platform_get_drvdata(pdev); | |
244 | ||
245 | sysfs_remove_bin_file(&pdev->dev.kobj, &ds1742_nvram_attr); | |
246 | rtc_device_unregister(pdata->rtc); | |
f9231a0c TER |
247 | iounmap(pdata->ioaddr_nvram); |
248 | release_mem_region(pdata->baseaddr, pdata->size); | |
5ec3e4b7 AN |
249 | kfree(pdata); |
250 | return 0; | |
251 | } | |
252 | ||
253 | static struct platform_driver ds1742_rtc_driver = { | |
254 | .probe = ds1742_rtc_probe, | |
255 | .remove = __devexit_p(ds1742_rtc_remove), | |
256 | .driver = { | |
a95e23a2 | 257 | .name = "rtc-ds1742", |
5ec3e4b7 AN |
258 | .owner = THIS_MODULE, |
259 | }, | |
260 | }; | |
261 | ||
262 | static __init int ds1742_init(void) | |
263 | { | |
264 | return platform_driver_register(&ds1742_rtc_driver); | |
265 | } | |
266 | ||
267 | static __exit void ds1742_exit(void) | |
268 | { | |
ef154ec6 | 269 | platform_driver_unregister(&ds1742_rtc_driver); |
5ec3e4b7 AN |
270 | } |
271 | ||
272 | module_init(ds1742_init); | |
273 | module_exit(ds1742_exit); | |
274 | ||
275 | MODULE_AUTHOR("Atsushi Nemoto <anemo@mba.ocn.ne.jp>"); | |
276 | MODULE_DESCRIPTION("Dallas DS1742 RTC driver"); | |
277 | MODULE_LICENSE("GPL"); | |
278 | MODULE_VERSION(DRV_VERSION); | |
ad28a07b | 279 | MODULE_ALIAS("platform:rtc-ds1742"); |