Commit | Line | Data |
---|---|---|
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> | |
5ec3e4b7 | 16 | #include <linux/kernel.h> |
5a0e3ad6 | 17 | #include <linux/gfp.h> |
5ec3e4b7 AN |
18 | #include <linux/delay.h> |
19 | #include <linux/jiffies.h> | |
20 | #include <linux/rtc.h> | |
663b3524 AS |
21 | #include <linux/of.h> |
22 | #include <linux/of_device.h> | |
5ec3e4b7 AN |
23 | #include <linux/platform_device.h> |
24 | #include <linux/io.h> | |
2113852b | 25 | #include <linux/module.h> |
5ec3e4b7 | 26 | |
ac18eb62 | 27 | #define DRV_VERSION "0.4" |
5ec3e4b7 | 28 | |
f9231a0c | 29 | #define RTC_SIZE 8 |
5ec3e4b7 | 30 | |
f9231a0c TER |
31 | #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 | |
5ec3e4b7 AN |
40 | |
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 | ||
55 | struct rtc_plat_data { | |
f9231a0c TER |
56 | void __iomem *ioaddr_nvram; |
57 | void __iomem *ioaddr_rtc; | |
58 | size_t size_nvram; | |
5ec3e4b7 | 59 | unsigned long last_jiffies; |
3a729700 | 60 | struct bin_attribute nvram_attr; |
5ec3e4b7 AN |
61 | }; |
62 | ||
63 | static 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); | |
f9231a0c | 67 | void __iomem *ioaddr = pdata->ioaddr_rtc; |
5ec3e4b7 AN |
68 | u8 century; |
69 | ||
fe20ba70 | 70 | century = bin2bcd((tm->tm_year + 1900) / 100); |
5ec3e4b7 AN |
71 | |
72 | writeb(RTC_WRITE, ioaddr + RTC_CONTROL); | |
73 | ||
fe20ba70 AB |
74 | 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); | |
5ec3e4b7 AN |
81 | |
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 | ||
88 | static 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); | |
f9231a0c | 92 | void __iomem *ioaddr = pdata->ioaddr_rtc; |
5ec3e4b7 AN |
93 | 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); | |
fe20ba70 AB |
110 | 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; | |
5ec3e4b7 | 116 | /* year is 1900 + tm->tm_year */ |
fe20ba70 | 117 | tm->tm_year = bcd2bin(year) + bcd2bin(century) * 100 - 1900; |
5ec3e4b7 | 118 | |
1735be4b | 119 | return rtc_valid_tm(tm); |
5ec3e4b7 AN |
120 | } |
121 | ||
ff8371ac | 122 | static const struct rtc_class_ops ds1742_rtc_ops = { |
5ec3e4b7 AN |
123 | .read_time = ds1742_rtc_read_time, |
124 | .set_time = ds1742_rtc_set_time, | |
125 | }; | |
126 | ||
2c3c8bea | 127 | static ssize_t ds1742_nvram_read(struct file *filp, struct kobject *kobj, |
91a69029 ZR |
128 | struct bin_attribute *bin_attr, |
129 | char *buf, loff_t pos, size_t size) | |
5ec3e4b7 | 130 | { |
50e49bee AN |
131 | struct device *dev = container_of(kobj, struct device, kobj); |
132 | struct platform_device *pdev = to_platform_device(dev); | |
5ec3e4b7 | 133 | struct rtc_plat_data *pdata = platform_get_drvdata(pdev); |
f9231a0c | 134 | void __iomem *ioaddr = pdata->ioaddr_nvram; |
5ec3e4b7 AN |
135 | ssize_t count; |
136 | ||
f9231a0c | 137 | for (count = 0; size > 0 && pos < pdata->size_nvram; count++, size--) |
5ec3e4b7 AN |
138 | *buf++ = readb(ioaddr + pos++); |
139 | return count; | |
140 | } | |
141 | ||
2c3c8bea | 142 | static ssize_t ds1742_nvram_write(struct file *filp, struct kobject *kobj, |
91a69029 ZR |
143 | struct bin_attribute *bin_attr, |
144 | char *buf, loff_t pos, size_t size) | |
5ec3e4b7 | 145 | { |
50e49bee AN |
146 | struct device *dev = container_of(kobj, struct device, kobj); |
147 | struct platform_device *pdev = to_platform_device(dev); | |
5ec3e4b7 | 148 | struct rtc_plat_data *pdata = platform_get_drvdata(pdev); |
f9231a0c | 149 | void __iomem *ioaddr = pdata->ioaddr_nvram; |
5ec3e4b7 AN |
150 | ssize_t count; |
151 | ||
f9231a0c | 152 | for (count = 0; size > 0 && pos < pdata->size_nvram; count++, size--) |
5ec3e4b7 AN |
153 | writeb(*buf++, ioaddr + pos++); |
154 | return count; | |
155 | } | |
156 | ||
5a167f45 | 157 | static int ds1742_rtc_probe(struct platform_device *pdev) |
5ec3e4b7 AN |
158 | { |
159 | struct rtc_device *rtc; | |
160 | struct resource *res; | |
161 | unsigned int cen, sec; | |
ac18eb62 AN |
162 | struct rtc_plat_data *pdata; |
163 | void __iomem *ioaddr; | |
5ec3e4b7 AN |
164 | int ret = 0; |
165 | ||
ac18eb62 | 166 | pdata = devm_kzalloc(&pdev->dev, sizeof(*pdata), GFP_KERNEL); |
5ec3e4b7 AN |
167 | if (!pdata) |
168 | return -ENOMEM; | |
25e2818e AS |
169 | |
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); | |
ac18eb62 | 174 | |
f9231a0c | 175 | pdata->ioaddr_nvram = ioaddr; |
25e2818e | 176 | pdata->size_nvram = resource_size(res) - RTC_SIZE; |
f9231a0c | 177 | pdata->ioaddr_rtc = ioaddr + pdata->size_nvram; |
5ec3e4b7 | 178 | |
f937331b | 179 | sysfs_bin_attr_init(&pdata->nvram_attr); |
3a729700 TER |
180 | 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 | ||
5ec3e4b7 | 186 | /* turn RTC on if it was not on */ |
f9231a0c | 187 | ioaddr = pdata->ioaddr_rtc; |
5ec3e4b7 AN |
188 | 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 | } | |
391b1fe6 | 196 | if (!(readb(ioaddr + RTC_DAY) & RTC_BATT_FLAG)) |
5ec3e4b7 AN |
197 | dev_warn(&pdev->dev, "voltage-low detected.\n"); |
198 | ||
ac18eb62 AN |
199 | pdata->last_jiffies = jiffies; |
200 | platform_set_drvdata(pdev, pdata); | |
f7cfdea0 | 201 | rtc = devm_rtc_device_register(&pdev->dev, pdev->name, |
5ec3e4b7 | 202 | &ds1742_rtc_ops, THIS_MODULE); |
ac18eb62 AN |
203 | if (IS_ERR(rtc)) |
204 | return PTR_ERR(rtc); | |
3a729700 TER |
205 | |
206 | ret = sysfs_create_bin_file(&pdev->dev.kobj, &pdata->nvram_attr); | |
4071ea25 AZ |
207 | if (ret) |
208 | dev_err(&pdev->dev, "Unable to create sysfs entry: %s\n", | |
209 | pdata->nvram_attr.attr.name); | |
f7cfdea0 | 210 | |
4071ea25 | 211 | return 0; |
5ec3e4b7 AN |
212 | } |
213 | ||
5a167f45 | 214 | static int ds1742_rtc_remove(struct platform_device *pdev) |
5ec3e4b7 AN |
215 | { |
216 | struct rtc_plat_data *pdata = platform_get_drvdata(pdev); | |
217 | ||
3a729700 | 218 | sysfs_remove_bin_file(&pdev->dev.kobj, &pdata->nvram_attr); |
5ec3e4b7 AN |
219 | return 0; |
220 | } | |
221 | ||
9d203572 | 222 | static const struct of_device_id __maybe_unused ds1742_rtc_of_match[] = { |
663b3524 AS |
223 | { .compatible = "maxim,ds1742", }, |
224 | { } | |
225 | }; | |
226 | MODULE_DEVICE_TABLE(of, ds1742_rtc_of_match); | |
227 | ||
5ec3e4b7 AN |
228 | static struct platform_driver ds1742_rtc_driver = { |
229 | .probe = ds1742_rtc_probe, | |
5a167f45 | 230 | .remove = ds1742_rtc_remove, |
5ec3e4b7 | 231 | .driver = { |
a95e23a2 | 232 | .name = "rtc-ds1742", |
5ec3e4b7 | 233 | .owner = THIS_MODULE, |
3710f597 | 234 | .of_match_table = of_match_ptr(ds1742_rtc_of_match), |
5ec3e4b7 AN |
235 | }, |
236 | }; | |
237 | ||
0c4eae66 | 238 | module_platform_driver(ds1742_rtc_driver); |
5ec3e4b7 AN |
239 | |
240 | MODULE_AUTHOR("Atsushi Nemoto <anemo@mba.ocn.ne.jp>"); | |
241 | MODULE_DESCRIPTION("Dallas DS1742 RTC driver"); | |
242 | MODULE_LICENSE("GPL"); | |
243 | MODULE_VERSION(DRV_VERSION); | |
ad28a07b | 244 | MODULE_ALIAS("platform:rtc-ds1742"); |