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path: root/drivers/rtc/rtc-rs5c372.c
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-rw-r--r--drivers/rtc/rtc-rs5c372.c294
1 files changed, 294 insertions, 0 deletions
diff --git a/drivers/rtc/rtc-rs5c372.c b/drivers/rtc/rtc-rs5c372.c
new file mode 100644
index 000000000000..396c8681f66c
--- /dev/null
+++ b/drivers/rtc/rtc-rs5c372.c
@@ -0,0 +1,294 @@
1/*
2 * An I2C driver for the Ricoh RS5C372 RTC
3 *
4 * Copyright (C) 2005 Pavel Mironchik <pmironchik@optifacio.net>
5 * Copyright (C) 2006 Tower Technologies
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
12#include <linux/i2c.h>
13#include <linux/rtc.h>
14#include <linux/bcd.h>
15
16#define DRV_VERSION "0.2"
17
18/* Addresses to scan */
19static unsigned short normal_i2c[] = { /* 0x32,*/ I2C_CLIENT_END };
20
21/* Insmod parameters */
22I2C_CLIENT_INSMOD;
23
24#define RS5C372_REG_SECS 0
25#define RS5C372_REG_MINS 1
26#define RS5C372_REG_HOURS 2
27#define RS5C372_REG_WDAY 3
28#define RS5C372_REG_DAY 4
29#define RS5C372_REG_MONTH 5
30#define RS5C372_REG_YEAR 6
31#define RS5C372_REG_TRIM 7
32
33#define RS5C372_TRIM_XSL 0x80
34#define RS5C372_TRIM_MASK 0x7F
35
36#define RS5C372_REG_BASE 0
37
38static int rs5c372_attach(struct i2c_adapter *adapter);
39static int rs5c372_detach(struct i2c_client *client);
40static int rs5c372_probe(struct i2c_adapter *adapter, int address, int kind);
41
42static struct i2c_driver rs5c372_driver = {
43 .driver = {
44 .name = "rs5c372",
45 },
46 .attach_adapter = &rs5c372_attach,
47 .detach_client = &rs5c372_detach,
48};
49
50static int rs5c372_get_datetime(struct i2c_client *client, struct rtc_time *tm)
51{
52 unsigned char buf[7] = { RS5C372_REG_BASE };
53
54 /* this implements the 1st reading method, according
55 * to the datasheet. buf[0] is initialized with
56 * address ptr and transmission format register.
57 */
58 struct i2c_msg msgs[] = {
59 { client->addr, 0, 1, buf },
60 { client->addr, I2C_M_RD, 7, buf },
61 };
62
63 if ((i2c_transfer(client->adapter, msgs, 2)) != 2) {
64 dev_err(&client->dev, "%s: read error\n", __FUNCTION__);
65 return -EIO;
66 }
67
68 tm->tm_sec = BCD2BIN(buf[RS5C372_REG_SECS] & 0x7f);
69 tm->tm_min = BCD2BIN(buf[RS5C372_REG_MINS] & 0x7f);
70 tm->tm_hour = BCD2BIN(buf[RS5C372_REG_HOURS] & 0x3f);
71 tm->tm_wday = BCD2BIN(buf[RS5C372_REG_WDAY] & 0x07);
72 tm->tm_mday = BCD2BIN(buf[RS5C372_REG_DAY] & 0x3f);
73
74 /* tm->tm_mon is zero-based */
75 tm->tm_mon = BCD2BIN(buf[RS5C372_REG_MONTH] & 0x1f) - 1;
76
77 /* year is 1900 + tm->tm_year */
78 tm->tm_year = BCD2BIN(buf[RS5C372_REG_YEAR]) + 100;
79
80 dev_dbg(&client->dev, "%s: tm is secs=%d, mins=%d, hours=%d, "
81 "mday=%d, mon=%d, year=%d, wday=%d\n",
82 __FUNCTION__,
83 tm->tm_sec, tm->tm_min, tm->tm_hour,
84 tm->tm_mday, tm->tm_mon, tm->tm_year, tm->tm_wday);
85
86 return 0;
87}
88
89static int rs5c372_set_datetime(struct i2c_client *client, struct rtc_time *tm)
90{
91 unsigned char buf[8] = { RS5C372_REG_BASE };
92
93 dev_dbg(&client->dev,
94 "%s: secs=%d, mins=%d, hours=%d ",
95 "mday=%d, mon=%d, year=%d, wday=%d\n",
96 __FUNCTION__, tm->tm_sec, tm->tm_min, tm->tm_hour,
97 tm->tm_mday, tm->tm_mon, tm->tm_year, tm->tm_wday);
98
99 buf[1] = BIN2BCD(tm->tm_sec);
100 buf[2] = BIN2BCD(tm->tm_min);
101 buf[3] = BIN2BCD(tm->tm_hour);
102 buf[4] = BIN2BCD(tm->tm_wday);
103 buf[5] = BIN2BCD(tm->tm_mday);
104 buf[6] = BIN2BCD(tm->tm_mon + 1);
105 buf[7] = BIN2BCD(tm->tm_year - 100);
106
107 if ((i2c_master_send(client, buf, 8)) != 8) {
108 dev_err(&client->dev, "%s: write error\n", __FUNCTION__);
109 return -EIO;
110 }
111
112 return 0;
113}
114
115static int rs5c372_get_trim(struct i2c_client *client, int *osc, int *trim)
116{
117 unsigned char buf = RS5C372_REG_TRIM;
118
119 struct i2c_msg msgs[] = {
120 { client->addr, 0, 1, &buf },
121 { client->addr, I2C_M_RD, 1, &buf },
122 };
123
124 if ((i2c_transfer(client->adapter, msgs, 2)) != 2) {
125 dev_err(&client->dev, "%s: read error\n", __FUNCTION__);
126 return -EIO;
127 }
128
129 dev_dbg(&client->dev, "%s: raw trim=%x\n", __FUNCTION__, trim);
130
131 if (osc)
132 *osc = (buf & RS5C372_TRIM_XSL) ? 32000 : 32768;
133
134 if (trim)
135 *trim = buf & RS5C372_TRIM_MASK;
136
137 return 0;
138}
139
140static int rs5c372_rtc_read_time(struct device *dev, struct rtc_time *tm)
141{
142 return rs5c372_get_datetime(to_i2c_client(dev), tm);
143}
144
145static int rs5c372_rtc_set_time(struct device *dev, struct rtc_time *tm)
146{
147 return rs5c372_set_datetime(to_i2c_client(dev), tm);
148}
149
150static int rs5c372_rtc_proc(struct device *dev, struct seq_file *seq)
151{
152 int err, osc, trim;
153
154 seq_printf(seq, "24hr\t\t: yes\n");
155
156 if ((err = rs5c372_get_trim(to_i2c_client(dev), &osc, &trim)) == 0) {
157 seq_printf(seq, "%d.%03d KHz\n", osc / 1000, osc % 1000);
158 seq_printf(seq, "trim\t: %d\n", trim);
159 }
160
161 return 0;
162}
163
164static struct rtc_class_ops rs5c372_rtc_ops = {
165 .proc = rs5c372_rtc_proc,
166 .read_time = rs5c372_rtc_read_time,
167 .set_time = rs5c372_rtc_set_time,
168};
169
170static ssize_t rs5c372_sysfs_show_trim(struct device *dev,
171 struct device_attribute *attr, char *buf)
172{
173 int trim;
174
175 if (rs5c372_get_trim(to_i2c_client(dev), NULL, &trim) == 0)
176 return sprintf(buf, "0x%2x\n", trim);
177
178 return 0;
179}
180static DEVICE_ATTR(trim, S_IRUGO, rs5c372_sysfs_show_trim, NULL);
181
182static ssize_t rs5c372_sysfs_show_osc(struct device *dev,
183 struct device_attribute *attr, char *buf)
184{
185 int osc;
186
187 if (rs5c372_get_trim(to_i2c_client(dev), &osc, NULL) == 0)
188 return sprintf(buf, "%d.%03d KHz\n", osc / 1000, osc % 1000);
189
190 return 0;
191}
192static DEVICE_ATTR(osc, S_IRUGO, rs5c372_sysfs_show_osc, NULL);
193
194static int rs5c372_attach(struct i2c_adapter *adapter)
195{
196 dev_dbg(&adapter->dev, "%s\n", __FUNCTION__);
197 return i2c_probe(adapter, &addr_data, rs5c372_probe);
198}
199
200static int rs5c372_probe(struct i2c_adapter *adapter, int address, int kind)
201{
202 int err = 0;
203 struct i2c_client *client;
204 struct rtc_device *rtc;
205
206 dev_dbg(&adapter->dev, "%s\n", __FUNCTION__);
207
208 if (!i2c_check_functionality(adapter, I2C_FUNC_I2C)) {
209 err = -ENODEV;
210 goto exit;
211 }
212
213 if (!(client = kzalloc(sizeof(struct i2c_client), GFP_KERNEL))) {
214 err = -ENOMEM;
215 goto exit;
216 }
217
218 /* I2C client */
219 client->addr = address;
220 client->driver = &rs5c372_driver;
221 client->adapter = adapter;
222
223 strlcpy(client->name, rs5c372_driver.driver.name, I2C_NAME_SIZE);
224
225 /* Inform the i2c layer */
226 if ((err = i2c_attach_client(client)))
227 goto exit_kfree;
228
229 dev_info(&client->dev, "chip found, driver version " DRV_VERSION "\n");
230
231 rtc = rtc_device_register(rs5c372_driver.driver.name, &client->dev,
232 &rs5c372_rtc_ops, THIS_MODULE);
233
234 if (IS_ERR(rtc)) {
235 err = PTR_ERR(rtc);
236 dev_err(&client->dev,
237 "unable to register the class device\n");
238 goto exit_detach;
239 }
240
241 i2c_set_clientdata(client, rtc);
242
243 device_create_file(&client->dev, &dev_attr_trim);
244 device_create_file(&client->dev, &dev_attr_osc);
245
246 return 0;
247
248exit_detach:
249 i2c_detach_client(client);
250
251exit_kfree:
252 kfree(client);
253
254exit:
255 return err;
256}
257
258static int rs5c372_detach(struct i2c_client *client)
259{
260 int err;
261 struct rtc_device *rtc = i2c_get_clientdata(client);
262
263 dev_dbg(&client->dev, "%s\n", __FUNCTION__);
264
265 if (rtc)
266 rtc_device_unregister(rtc);
267
268 if ((err = i2c_detach_client(client)))
269 return err;
270
271 kfree(client);
272
273 return 0;
274}
275
276static __init int rs5c372_init(void)
277{
278 return i2c_add_driver(&rs5c372_driver);
279}
280
281static __exit void rs5c372_exit(void)
282{
283 i2c_del_driver(&rs5c372_driver);
284}
285
286module_init(rs5c372_init);
287module_exit(rs5c372_exit);
288
289MODULE_AUTHOR(
290 "Pavel Mironchik <pmironchik@optifacio.net>, "
291 "Alessandro Zummo <a.zummo@towertech.it>");
292MODULE_DESCRIPTION("Ricoh RS5C372 RTC driver");
293MODULE_LICENSE("GPL");
294MODULE_VERSION(DRV_VERSION);