Loading...
1/*
2 * ST M48T86 / Dallas DS12887 RTC driver
3 * Copyright (c) 2006 Tower Technologies
4 *
5 * Author: Alessandro Zummo <a.zummo@towertech.it>
6 *
7 * This program is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License version 2 as
9 * published by the Free Software Foundation.
10 *
11 * This drivers only supports the clock running in BCD and 24H mode.
12 * If it will be ever adapted to binary and 12H mode, care must be taken
13 * to not introduce bugs.
14 */
15
16#include <linux/module.h>
17#include <linux/rtc.h>
18#include <linux/platform_device.h>
19#include <linux/m48t86.h>
20#include <linux/bcd.h>
21
22#define M48T86_REG_SEC 0x00
23#define M48T86_REG_SECALRM 0x01
24#define M48T86_REG_MIN 0x02
25#define M48T86_REG_MINALRM 0x03
26#define M48T86_REG_HOUR 0x04
27#define M48T86_REG_HOURALRM 0x05
28#define M48T86_REG_DOW 0x06 /* 1 = sunday */
29#define M48T86_REG_DOM 0x07
30#define M48T86_REG_MONTH 0x08 /* 1 - 12 */
31#define M48T86_REG_YEAR 0x09 /* 0 - 99 */
32#define M48T86_REG_A 0x0A
33#define M48T86_REG_B 0x0B
34#define M48T86_REG_C 0x0C
35#define M48T86_REG_D 0x0D
36
37#define M48T86_REG_B_H24 (1 << 1)
38#define M48T86_REG_B_DM (1 << 2)
39#define M48T86_REG_B_SET (1 << 7)
40#define M48T86_REG_D_VRT (1 << 7)
41
42#define DRV_VERSION "0.1"
43
44
45static int m48t86_rtc_read_time(struct device *dev, struct rtc_time *tm)
46{
47 unsigned char reg;
48 struct platform_device *pdev = to_platform_device(dev);
49 struct m48t86_ops *ops = pdev->dev.platform_data;
50
51 reg = ops->readbyte(M48T86_REG_B);
52
53 if (reg & M48T86_REG_B_DM) {
54 /* data (binary) mode */
55 tm->tm_sec = ops->readbyte(M48T86_REG_SEC);
56 tm->tm_min = ops->readbyte(M48T86_REG_MIN);
57 tm->tm_hour = ops->readbyte(M48T86_REG_HOUR) & 0x3F;
58 tm->tm_mday = ops->readbyte(M48T86_REG_DOM);
59 /* tm_mon is 0-11 */
60 tm->tm_mon = ops->readbyte(M48T86_REG_MONTH) - 1;
61 tm->tm_year = ops->readbyte(M48T86_REG_YEAR) + 100;
62 tm->tm_wday = ops->readbyte(M48T86_REG_DOW);
63 } else {
64 /* bcd mode */
65 tm->tm_sec = bcd2bin(ops->readbyte(M48T86_REG_SEC));
66 tm->tm_min = bcd2bin(ops->readbyte(M48T86_REG_MIN));
67 tm->tm_hour = bcd2bin(ops->readbyte(M48T86_REG_HOUR) & 0x3F);
68 tm->tm_mday = bcd2bin(ops->readbyte(M48T86_REG_DOM));
69 /* tm_mon is 0-11 */
70 tm->tm_mon = bcd2bin(ops->readbyte(M48T86_REG_MONTH)) - 1;
71 tm->tm_year = bcd2bin(ops->readbyte(M48T86_REG_YEAR)) + 100;
72 tm->tm_wday = bcd2bin(ops->readbyte(M48T86_REG_DOW));
73 }
74
75 /* correct the hour if the clock is in 12h mode */
76 if (!(reg & M48T86_REG_B_H24))
77 if (ops->readbyte(M48T86_REG_HOUR) & 0x80)
78 tm->tm_hour += 12;
79
80 return rtc_valid_tm(tm);
81}
82
83static int m48t86_rtc_set_time(struct device *dev, struct rtc_time *tm)
84{
85 unsigned char reg;
86 struct platform_device *pdev = to_platform_device(dev);
87 struct m48t86_ops *ops = pdev->dev.platform_data;
88
89 reg = ops->readbyte(M48T86_REG_B);
90
91 /* update flag and 24h mode */
92 reg |= M48T86_REG_B_SET | M48T86_REG_B_H24;
93 ops->writebyte(reg, M48T86_REG_B);
94
95 if (reg & M48T86_REG_B_DM) {
96 /* data (binary) mode */
97 ops->writebyte(tm->tm_sec, M48T86_REG_SEC);
98 ops->writebyte(tm->tm_min, M48T86_REG_MIN);
99 ops->writebyte(tm->tm_hour, M48T86_REG_HOUR);
100 ops->writebyte(tm->tm_mday, M48T86_REG_DOM);
101 ops->writebyte(tm->tm_mon + 1, M48T86_REG_MONTH);
102 ops->writebyte(tm->tm_year % 100, M48T86_REG_YEAR);
103 ops->writebyte(tm->tm_wday, M48T86_REG_DOW);
104 } else {
105 /* bcd mode */
106 ops->writebyte(bin2bcd(tm->tm_sec), M48T86_REG_SEC);
107 ops->writebyte(bin2bcd(tm->tm_min), M48T86_REG_MIN);
108 ops->writebyte(bin2bcd(tm->tm_hour), M48T86_REG_HOUR);
109 ops->writebyte(bin2bcd(tm->tm_mday), M48T86_REG_DOM);
110 ops->writebyte(bin2bcd(tm->tm_mon + 1), M48T86_REG_MONTH);
111 ops->writebyte(bin2bcd(tm->tm_year % 100), M48T86_REG_YEAR);
112 ops->writebyte(bin2bcd(tm->tm_wday), M48T86_REG_DOW);
113 }
114
115 /* update ended */
116 reg &= ~M48T86_REG_B_SET;
117 ops->writebyte(reg, M48T86_REG_B);
118
119 return 0;
120}
121
122static int m48t86_rtc_proc(struct device *dev, struct seq_file *seq)
123{
124 unsigned char reg;
125 struct platform_device *pdev = to_platform_device(dev);
126 struct m48t86_ops *ops = pdev->dev.platform_data;
127
128 reg = ops->readbyte(M48T86_REG_B);
129
130 seq_printf(seq, "mode\t\t: %s\n",
131 (reg & M48T86_REG_B_DM) ? "binary" : "bcd");
132
133 reg = ops->readbyte(M48T86_REG_D);
134
135 seq_printf(seq, "battery\t\t: %s\n",
136 (reg & M48T86_REG_D_VRT) ? "ok" : "exhausted");
137
138 return 0;
139}
140
141static const struct rtc_class_ops m48t86_rtc_ops = {
142 .read_time = m48t86_rtc_read_time,
143 .set_time = m48t86_rtc_set_time,
144 .proc = m48t86_rtc_proc,
145};
146
147static int __devinit m48t86_rtc_probe(struct platform_device *dev)
148{
149 unsigned char reg;
150 struct m48t86_ops *ops = dev->dev.platform_data;
151 struct rtc_device *rtc = rtc_device_register("m48t86",
152 &dev->dev, &m48t86_rtc_ops, THIS_MODULE);
153
154 if (IS_ERR(rtc))
155 return PTR_ERR(rtc);
156
157 platform_set_drvdata(dev, rtc);
158
159 /* read battery status */
160 reg = ops->readbyte(M48T86_REG_D);
161 dev_info(&dev->dev, "battery %s\n",
162 (reg & M48T86_REG_D_VRT) ? "ok" : "exhausted");
163
164 return 0;
165}
166
167static int __devexit m48t86_rtc_remove(struct platform_device *dev)
168{
169 struct rtc_device *rtc = platform_get_drvdata(dev);
170
171 if (rtc)
172 rtc_device_unregister(rtc);
173
174 platform_set_drvdata(dev, NULL);
175
176 return 0;
177}
178
179static struct platform_driver m48t86_rtc_platform_driver = {
180 .driver = {
181 .name = "rtc-m48t86",
182 .owner = THIS_MODULE,
183 },
184 .probe = m48t86_rtc_probe,
185 .remove = __devexit_p(m48t86_rtc_remove),
186};
187
188module_platform_driver(m48t86_rtc_platform_driver);
189
190MODULE_AUTHOR("Alessandro Zummo <a.zummo@towertech.it>");
191MODULE_DESCRIPTION("M48T86 RTC driver");
192MODULE_LICENSE("GPL");
193MODULE_VERSION(DRV_VERSION);
194MODULE_ALIAS("platform:rtc-m48t86");
1/*
2 * ST M48T86 / Dallas DS12887 RTC driver
3 * Copyright (c) 2006 Tower Technologies
4 *
5 * Author: Alessandro Zummo <a.zummo@towertech.it>
6 *
7 * This program is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License version 2 as
9 * published by the Free Software Foundation.
10 *
11 * This drivers only supports the clock running in BCD and 24H mode.
12 * If it will be ever adapted to binary and 12H mode, care must be taken
13 * to not introduce bugs.
14 */
15
16#include <linux/module.h>
17#include <linux/rtc.h>
18#include <linux/platform_device.h>
19#include <linux/platform_data/rtc-m48t86.h>
20#include <linux/bcd.h>
21
22#define M48T86_REG_SEC 0x00
23#define M48T86_REG_SECALRM 0x01
24#define M48T86_REG_MIN 0x02
25#define M48T86_REG_MINALRM 0x03
26#define M48T86_REG_HOUR 0x04
27#define M48T86_REG_HOURALRM 0x05
28#define M48T86_REG_DOW 0x06 /* 1 = sunday */
29#define M48T86_REG_DOM 0x07
30#define M48T86_REG_MONTH 0x08 /* 1 - 12 */
31#define M48T86_REG_YEAR 0x09 /* 0 - 99 */
32#define M48T86_REG_A 0x0A
33#define M48T86_REG_B 0x0B
34#define M48T86_REG_C 0x0C
35#define M48T86_REG_D 0x0D
36
37#define M48T86_REG_B_H24 (1 << 1)
38#define M48T86_REG_B_DM (1 << 2)
39#define M48T86_REG_B_SET (1 << 7)
40#define M48T86_REG_D_VRT (1 << 7)
41
42static int m48t86_rtc_read_time(struct device *dev, struct rtc_time *tm)
43{
44 unsigned char reg;
45 struct platform_device *pdev = to_platform_device(dev);
46 struct m48t86_ops *ops = dev_get_platdata(&pdev->dev);
47
48 reg = ops->readbyte(M48T86_REG_B);
49
50 if (reg & M48T86_REG_B_DM) {
51 /* data (binary) mode */
52 tm->tm_sec = ops->readbyte(M48T86_REG_SEC);
53 tm->tm_min = ops->readbyte(M48T86_REG_MIN);
54 tm->tm_hour = ops->readbyte(M48T86_REG_HOUR) & 0x3F;
55 tm->tm_mday = ops->readbyte(M48T86_REG_DOM);
56 /* tm_mon is 0-11 */
57 tm->tm_mon = ops->readbyte(M48T86_REG_MONTH) - 1;
58 tm->tm_year = ops->readbyte(M48T86_REG_YEAR) + 100;
59 tm->tm_wday = ops->readbyte(M48T86_REG_DOW);
60 } else {
61 /* bcd mode */
62 tm->tm_sec = bcd2bin(ops->readbyte(M48T86_REG_SEC));
63 tm->tm_min = bcd2bin(ops->readbyte(M48T86_REG_MIN));
64 tm->tm_hour = bcd2bin(ops->readbyte(M48T86_REG_HOUR) & 0x3F);
65 tm->tm_mday = bcd2bin(ops->readbyte(M48T86_REG_DOM));
66 /* tm_mon is 0-11 */
67 tm->tm_mon = bcd2bin(ops->readbyte(M48T86_REG_MONTH)) - 1;
68 tm->tm_year = bcd2bin(ops->readbyte(M48T86_REG_YEAR)) + 100;
69 tm->tm_wday = bcd2bin(ops->readbyte(M48T86_REG_DOW));
70 }
71
72 /* correct the hour if the clock is in 12h mode */
73 if (!(reg & M48T86_REG_B_H24))
74 if (ops->readbyte(M48T86_REG_HOUR) & 0x80)
75 tm->tm_hour += 12;
76
77 return rtc_valid_tm(tm);
78}
79
80static int m48t86_rtc_set_time(struct device *dev, struct rtc_time *tm)
81{
82 unsigned char reg;
83 struct platform_device *pdev = to_platform_device(dev);
84 struct m48t86_ops *ops = dev_get_platdata(&pdev->dev);
85
86 reg = ops->readbyte(M48T86_REG_B);
87
88 /* update flag and 24h mode */
89 reg |= M48T86_REG_B_SET | M48T86_REG_B_H24;
90 ops->writebyte(reg, M48T86_REG_B);
91
92 if (reg & M48T86_REG_B_DM) {
93 /* data (binary) mode */
94 ops->writebyte(tm->tm_sec, M48T86_REG_SEC);
95 ops->writebyte(tm->tm_min, M48T86_REG_MIN);
96 ops->writebyte(tm->tm_hour, M48T86_REG_HOUR);
97 ops->writebyte(tm->tm_mday, M48T86_REG_DOM);
98 ops->writebyte(tm->tm_mon + 1, M48T86_REG_MONTH);
99 ops->writebyte(tm->tm_year % 100, M48T86_REG_YEAR);
100 ops->writebyte(tm->tm_wday, M48T86_REG_DOW);
101 } else {
102 /* bcd mode */
103 ops->writebyte(bin2bcd(tm->tm_sec), M48T86_REG_SEC);
104 ops->writebyte(bin2bcd(tm->tm_min), M48T86_REG_MIN);
105 ops->writebyte(bin2bcd(tm->tm_hour), M48T86_REG_HOUR);
106 ops->writebyte(bin2bcd(tm->tm_mday), M48T86_REG_DOM);
107 ops->writebyte(bin2bcd(tm->tm_mon + 1), M48T86_REG_MONTH);
108 ops->writebyte(bin2bcd(tm->tm_year % 100), M48T86_REG_YEAR);
109 ops->writebyte(bin2bcd(tm->tm_wday), M48T86_REG_DOW);
110 }
111
112 /* update ended */
113 reg &= ~M48T86_REG_B_SET;
114 ops->writebyte(reg, M48T86_REG_B);
115
116 return 0;
117}
118
119static int m48t86_rtc_proc(struct device *dev, struct seq_file *seq)
120{
121 unsigned char reg;
122 struct platform_device *pdev = to_platform_device(dev);
123 struct m48t86_ops *ops = dev_get_platdata(&pdev->dev);
124
125 reg = ops->readbyte(M48T86_REG_B);
126
127 seq_printf(seq, "mode\t\t: %s\n",
128 (reg & M48T86_REG_B_DM) ? "binary" : "bcd");
129
130 reg = ops->readbyte(M48T86_REG_D);
131
132 seq_printf(seq, "battery\t\t: %s\n",
133 (reg & M48T86_REG_D_VRT) ? "ok" : "exhausted");
134
135 return 0;
136}
137
138static const struct rtc_class_ops m48t86_rtc_ops = {
139 .read_time = m48t86_rtc_read_time,
140 .set_time = m48t86_rtc_set_time,
141 .proc = m48t86_rtc_proc,
142};
143
144static int m48t86_rtc_probe(struct platform_device *dev)
145{
146 unsigned char reg;
147 struct m48t86_ops *ops = dev_get_platdata(&dev->dev);
148 struct rtc_device *rtc;
149
150 rtc = devm_rtc_device_register(&dev->dev, "m48t86",
151 &m48t86_rtc_ops, THIS_MODULE);
152
153 if (IS_ERR(rtc))
154 return PTR_ERR(rtc);
155
156 platform_set_drvdata(dev, rtc);
157
158 /* read battery status */
159 reg = ops->readbyte(M48T86_REG_D);
160 dev_info(&dev->dev, "battery %s\n",
161 (reg & M48T86_REG_D_VRT) ? "ok" : "exhausted");
162
163 return 0;
164}
165
166static struct platform_driver m48t86_rtc_platform_driver = {
167 .driver = {
168 .name = "rtc-m48t86",
169 },
170 .probe = m48t86_rtc_probe,
171};
172
173module_platform_driver(m48t86_rtc_platform_driver);
174
175MODULE_AUTHOR("Alessandro Zummo <a.zummo@towertech.it>");
176MODULE_DESCRIPTION("M48T86 RTC driver");
177MODULE_LICENSE("GPL");
178MODULE_ALIAS("platform:rtc-m48t86");