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c46288b0 BB |
1 | /* |
2 | * Seiko Instruments S-35390A RTC Driver | |
3 | * | |
4 | * Copyright (c) 2007 Byron Bradley | |
5 | * | |
6 | * This program is free software; you can redistribute it and/or | |
7 | * modify it under the terms of the GNU General Public License | |
8 | * as published by the Free Software Foundation; either version | |
9 | * 2 of the License, or (at your option) any later version. | |
10 | */ | |
11 | ||
12 | #include <linux/module.h> | |
13 | #include <linux/rtc.h> | |
14 | #include <linux/i2c.h> | |
15 | #include <linux/bitrev.h> | |
16 | #include <linux/bcd.h> | |
17 | #include <linux/slab.h> | |
18 | ||
19 | #define S35390A_CMD_STATUS1 0 | |
20 | #define S35390A_CMD_STATUS2 1 | |
21 | #define S35390A_CMD_TIME1 2 | |
22 | ||
23 | #define S35390A_BYTE_YEAR 0 | |
24 | #define S35390A_BYTE_MONTH 1 | |
25 | #define S35390A_BYTE_DAY 2 | |
26 | #define S35390A_BYTE_WDAY 3 | |
27 | #define S35390A_BYTE_HOURS 4 | |
28 | #define S35390A_BYTE_MINS 5 | |
29 | #define S35390A_BYTE_SECS 6 | |
30 | ||
31 | #define S35390A_FLAG_POC 0x01 | |
32 | #define S35390A_FLAG_BLD 0x02 | |
33 | #define S35390A_FLAG_24H 0x40 | |
34 | #define S35390A_FLAG_RESET 0x80 | |
35 | #define S35390A_FLAG_TEST 0x01 | |
36 | ||
37 | struct s35390a { | |
38 | struct i2c_client *client[8]; | |
39 | struct rtc_device *rtc; | |
40 | int twentyfourhour; | |
41 | }; | |
42 | ||
43 | static int s35390a_set_reg(struct s35390a *s35390a, int reg, char *buf, int len) | |
44 | { | |
45 | struct i2c_client *client = s35390a->client[reg]; | |
46 | struct i2c_msg msg[] = { | |
47 | { client->addr, 0, len, buf }, | |
48 | }; | |
49 | ||
50 | if ((i2c_transfer(client->adapter, msg, 1)) != 1) | |
51 | return -EIO; | |
52 | ||
53 | return 0; | |
54 | } | |
55 | ||
56 | static int s35390a_get_reg(struct s35390a *s35390a, int reg, char *buf, int len) | |
57 | { | |
58 | struct i2c_client *client = s35390a->client[reg]; | |
59 | struct i2c_msg msg[] = { | |
60 | { client->addr, I2C_M_RD, len, buf }, | |
61 | }; | |
62 | ||
63 | if ((i2c_transfer(client->adapter, msg, 1)) != 1) | |
64 | return -EIO; | |
65 | ||
66 | return 0; | |
67 | } | |
68 | ||
69 | static int s35390a_reset(struct s35390a *s35390a) | |
70 | { | |
71 | char buf[1]; | |
72 | ||
73 | if (s35390a_get_reg(s35390a, S35390A_CMD_STATUS1, buf, sizeof(buf)) < 0) | |
74 | return -EIO; | |
75 | ||
76 | if (!(buf[0] & (S35390A_FLAG_POC | S35390A_FLAG_BLD))) | |
77 | return 0; | |
78 | ||
79 | buf[0] |= (S35390A_FLAG_RESET | S35390A_FLAG_24H); | |
80 | buf[0] &= 0xf0; | |
81 | return s35390a_set_reg(s35390a, S35390A_CMD_STATUS1, buf, sizeof(buf)); | |
82 | } | |
83 | ||
84 | static int s35390a_disable_test_mode(struct s35390a *s35390a) | |
85 | { | |
86 | char buf[1]; | |
87 | ||
88 | if (s35390a_get_reg(s35390a, S35390A_CMD_STATUS2, buf, sizeof(buf)) < 0) | |
89 | return -EIO; | |
90 | ||
91 | if (!(buf[0] & S35390A_FLAG_TEST)) | |
92 | return 0; | |
93 | ||
94 | buf[0] &= ~S35390A_FLAG_TEST; | |
95 | return s35390a_set_reg(s35390a, S35390A_CMD_STATUS2, buf, sizeof(buf)); | |
96 | } | |
97 | ||
98 | static char s35390a_hr2reg(struct s35390a *s35390a, int hour) | |
99 | { | |
100 | if (s35390a->twentyfourhour) | |
101 | return BIN2BCD(hour); | |
102 | ||
103 | if (hour < 12) | |
104 | return BIN2BCD(hour); | |
105 | ||
106 | return 0x40 | BIN2BCD(hour - 12); | |
107 | } | |
108 | ||
109 | static int s35390a_reg2hr(struct s35390a *s35390a, char reg) | |
110 | { | |
111 | unsigned hour; | |
112 | ||
113 | if (s35390a->twentyfourhour) | |
114 | return BCD2BIN(reg & 0x3f); | |
115 | ||
116 | hour = BCD2BIN(reg & 0x3f); | |
117 | if (reg & 0x40) | |
118 | hour += 12; | |
119 | ||
120 | return hour; | |
121 | } | |
122 | ||
123 | static int s35390a_set_datetime(struct i2c_client *client, struct rtc_time *tm) | |
124 | { | |
125 | struct s35390a *s35390a = i2c_get_clientdata(client); | |
126 | int i, err; | |
127 | char buf[7]; | |
128 | ||
129 | dev_dbg(&client->dev, "%s: tm is secs=%d, mins=%d, hours=%d mday=%d, " | |
130 | "mon=%d, year=%d, wday=%d\n", __func__, tm->tm_sec, | |
131 | tm->tm_min, tm->tm_hour, tm->tm_mday, tm->tm_mon, tm->tm_year, | |
132 | tm->tm_wday); | |
133 | ||
134 | buf[S35390A_BYTE_YEAR] = BIN2BCD(tm->tm_year - 100); | |
135 | buf[S35390A_BYTE_MONTH] = BIN2BCD(tm->tm_mon + 1); | |
136 | buf[S35390A_BYTE_DAY] = BIN2BCD(tm->tm_mday); | |
137 | buf[S35390A_BYTE_WDAY] = BIN2BCD(tm->tm_wday); | |
138 | buf[S35390A_BYTE_HOURS] = s35390a_hr2reg(s35390a, tm->tm_hour); | |
139 | buf[S35390A_BYTE_MINS] = BIN2BCD(tm->tm_min); | |
140 | buf[S35390A_BYTE_SECS] = BIN2BCD(tm->tm_sec); | |
141 | ||
142 | /* This chip expects the bits of each byte to be in reverse order */ | |
143 | for (i = 0; i < 7; ++i) | |
144 | buf[i] = bitrev8(buf[i]); | |
145 | ||
146 | err = s35390a_set_reg(s35390a, S35390A_CMD_TIME1, buf, sizeof(buf)); | |
147 | ||
148 | return err; | |
149 | } | |
150 | ||
151 | static int s35390a_get_datetime(struct i2c_client *client, struct rtc_time *tm) | |
152 | { | |
153 | struct s35390a *s35390a = i2c_get_clientdata(client); | |
154 | char buf[7]; | |
155 | int i, err; | |
156 | ||
157 | err = s35390a_get_reg(s35390a, S35390A_CMD_TIME1, buf, sizeof(buf)); | |
158 | if (err < 0) | |
159 | return err; | |
160 | ||
161 | /* This chip returns the bits of each byte in reverse order */ | |
162 | for (i = 0; i < 7; ++i) | |
163 | buf[i] = bitrev8(buf[i]); | |
164 | ||
165 | tm->tm_sec = BCD2BIN(buf[S35390A_BYTE_SECS]); | |
166 | tm->tm_min = BCD2BIN(buf[S35390A_BYTE_MINS]); | |
167 | tm->tm_hour = s35390a_reg2hr(s35390a, buf[S35390A_BYTE_HOURS]); | |
168 | tm->tm_wday = BCD2BIN(buf[S35390A_BYTE_WDAY]); | |
169 | tm->tm_mday = BCD2BIN(buf[S35390A_BYTE_DAY]); | |
170 | tm->tm_mon = BCD2BIN(buf[S35390A_BYTE_MONTH]) - 1; | |
171 | tm->tm_year = BCD2BIN(buf[S35390A_BYTE_YEAR]) + 100; | |
172 | ||
173 | dev_dbg(&client->dev, "%s: tm is secs=%d, mins=%d, hours=%d, mday=%d, " | |
174 | "mon=%d, year=%d, wday=%d\n", __func__, tm->tm_sec, | |
175 | tm->tm_min, tm->tm_hour, tm->tm_mday, tm->tm_mon, tm->tm_year, | |
176 | tm->tm_wday); | |
177 | ||
178 | return rtc_valid_tm(tm); | |
179 | } | |
180 | ||
181 | static int s35390a_rtc_read_time(struct device *dev, struct rtc_time *tm) | |
182 | { | |
183 | return s35390a_get_datetime(to_i2c_client(dev), tm); | |
184 | } | |
185 | ||
186 | static int s35390a_rtc_set_time(struct device *dev, struct rtc_time *tm) | |
187 | { | |
188 | return s35390a_set_datetime(to_i2c_client(dev), tm); | |
189 | } | |
190 | ||
191 | static const struct rtc_class_ops s35390a_rtc_ops = { | |
192 | .read_time = s35390a_rtc_read_time, | |
193 | .set_time = s35390a_rtc_set_time, | |
194 | }; | |
195 | ||
196 | static struct i2c_driver s35390a_driver; | |
197 | ||
d2653e92 JD |
198 | static int s35390a_probe(struct i2c_client *client, |
199 | const struct i2c_device_id *id) | |
c46288b0 BB |
200 | { |
201 | int err; | |
202 | unsigned int i; | |
203 | struct s35390a *s35390a; | |
204 | struct rtc_time tm; | |
205 | char buf[1]; | |
206 | ||
207 | if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) { | |
208 | err = -ENODEV; | |
209 | goto exit; | |
210 | } | |
211 | ||
212 | s35390a = kzalloc(sizeof(struct s35390a), GFP_KERNEL); | |
213 | if (!s35390a) { | |
214 | err = -ENOMEM; | |
215 | goto exit; | |
216 | } | |
217 | ||
218 | s35390a->client[0] = client; | |
219 | i2c_set_clientdata(client, s35390a); | |
220 | ||
221 | /* This chip uses multiple addresses, use dummy devices for them */ | |
222 | for (i = 1; i < 8; ++i) { | |
223 | s35390a->client[i] = i2c_new_dummy(client->adapter, | |
224 | client->addr + i, "rtc-s35390a"); | |
225 | if (!s35390a->client[i]) { | |
226 | dev_err(&client->dev, "Address %02x unavailable\n", | |
227 | client->addr + i); | |
228 | err = -EBUSY; | |
229 | goto exit_dummy; | |
230 | } | |
231 | } | |
232 | ||
233 | err = s35390a_reset(s35390a); | |
234 | if (err < 0) { | |
235 | dev_err(&client->dev, "error resetting chip\n"); | |
236 | goto exit_dummy; | |
237 | } | |
238 | ||
239 | err = s35390a_disable_test_mode(s35390a); | |
240 | if (err < 0) { | |
241 | dev_err(&client->dev, "error disabling test mode\n"); | |
242 | goto exit_dummy; | |
243 | } | |
244 | ||
245 | err = s35390a_get_reg(s35390a, S35390A_CMD_STATUS1, buf, sizeof(buf)); | |
246 | if (err < 0) { | |
247 | dev_err(&client->dev, "error checking 12/24 hour mode\n"); | |
248 | goto exit_dummy; | |
249 | } | |
250 | if (buf[0] & S35390A_FLAG_24H) | |
251 | s35390a->twentyfourhour = 1; | |
252 | else | |
253 | s35390a->twentyfourhour = 0; | |
254 | ||
255 | if (s35390a_get_datetime(client, &tm) < 0) | |
256 | dev_warn(&client->dev, "clock needs to be set\n"); | |
257 | ||
258 | s35390a->rtc = rtc_device_register(s35390a_driver.driver.name, | |
259 | &client->dev, &s35390a_rtc_ops, THIS_MODULE); | |
260 | ||
261 | if (IS_ERR(s35390a->rtc)) { | |
262 | err = PTR_ERR(s35390a->rtc); | |
263 | goto exit_dummy; | |
264 | } | |
265 | return 0; | |
266 | ||
267 | exit_dummy: | |
268 | for (i = 1; i < 8; ++i) | |
269 | if (s35390a->client[i]) | |
270 | i2c_unregister_device(s35390a->client[i]); | |
271 | kfree(s35390a); | |
272 | i2c_set_clientdata(client, NULL); | |
273 | ||
274 | exit: | |
275 | return err; | |
276 | } | |
277 | ||
278 | static int s35390a_remove(struct i2c_client *client) | |
279 | { | |
280 | unsigned int i; | |
281 | ||
282 | struct s35390a *s35390a = i2c_get_clientdata(client); | |
283 | for (i = 1; i < 8; ++i) | |
284 | if (s35390a->client[i]) | |
285 | i2c_unregister_device(s35390a->client[i]); | |
286 | ||
287 | rtc_device_unregister(s35390a->rtc); | |
288 | kfree(s35390a); | |
289 | i2c_set_clientdata(client, NULL); | |
290 | ||
291 | return 0; | |
292 | } | |
293 | ||
294 | static struct i2c_driver s35390a_driver = { | |
295 | .driver = { | |
296 | .name = "rtc-s35390a", | |
297 | }, | |
298 | .probe = s35390a_probe, | |
299 | .remove = s35390a_remove, | |
300 | }; | |
301 | ||
302 | static int __init s35390a_rtc_init(void) | |
303 | { | |
304 | return i2c_add_driver(&s35390a_driver); | |
305 | } | |
306 | ||
307 | static void __exit s35390a_rtc_exit(void) | |
308 | { | |
309 | i2c_del_driver(&s35390a_driver); | |
310 | } | |
311 | ||
312 | MODULE_AUTHOR("Byron Bradley <byron.bbradley@gmail.com>"); | |
313 | MODULE_DESCRIPTION("S35390A RTC driver"); | |
314 | MODULE_LICENSE("GPL"); | |
315 | ||
316 | module_init(s35390a_rtc_init); | |
317 | module_exit(s35390a_rtc_exit); |