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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 | ||
3760f736 JD |
37 | static const struct i2c_device_id s35390a_id[] = { |
38 | { "s35390a", 0 }, | |
39 | { } | |
40 | }; | |
41 | MODULE_DEVICE_TABLE(i2c, s35390a_id); | |
42 | ||
c46288b0 BB |
43 | struct s35390a { |
44 | struct i2c_client *client[8]; | |
45 | struct rtc_device *rtc; | |
46 | int twentyfourhour; | |
47 | }; | |
48 | ||
49 | static int s35390a_set_reg(struct s35390a *s35390a, int reg, char *buf, int len) | |
50 | { | |
51 | struct i2c_client *client = s35390a->client[reg]; | |
52 | struct i2c_msg msg[] = { | |
53 | { client->addr, 0, len, buf }, | |
54 | }; | |
55 | ||
56 | if ((i2c_transfer(client->adapter, msg, 1)) != 1) | |
57 | return -EIO; | |
58 | ||
59 | return 0; | |
60 | } | |
61 | ||
62 | static int s35390a_get_reg(struct s35390a *s35390a, int reg, char *buf, int len) | |
63 | { | |
64 | struct i2c_client *client = s35390a->client[reg]; | |
65 | struct i2c_msg msg[] = { | |
66 | { client->addr, I2C_M_RD, len, buf }, | |
67 | }; | |
68 | ||
69 | if ((i2c_transfer(client->adapter, msg, 1)) != 1) | |
70 | return -EIO; | |
71 | ||
72 | return 0; | |
73 | } | |
74 | ||
75 | static int s35390a_reset(struct s35390a *s35390a) | |
76 | { | |
77 | char buf[1]; | |
78 | ||
79 | if (s35390a_get_reg(s35390a, S35390A_CMD_STATUS1, buf, sizeof(buf)) < 0) | |
80 | return -EIO; | |
81 | ||
82 | if (!(buf[0] & (S35390A_FLAG_POC | S35390A_FLAG_BLD))) | |
83 | return 0; | |
84 | ||
85 | buf[0] |= (S35390A_FLAG_RESET | S35390A_FLAG_24H); | |
86 | buf[0] &= 0xf0; | |
87 | return s35390a_set_reg(s35390a, S35390A_CMD_STATUS1, buf, sizeof(buf)); | |
88 | } | |
89 | ||
90 | static int s35390a_disable_test_mode(struct s35390a *s35390a) | |
91 | { | |
92 | char buf[1]; | |
93 | ||
94 | if (s35390a_get_reg(s35390a, S35390A_CMD_STATUS2, buf, sizeof(buf)) < 0) | |
95 | return -EIO; | |
96 | ||
97 | if (!(buf[0] & S35390A_FLAG_TEST)) | |
98 | return 0; | |
99 | ||
100 | buf[0] &= ~S35390A_FLAG_TEST; | |
101 | return s35390a_set_reg(s35390a, S35390A_CMD_STATUS2, buf, sizeof(buf)); | |
102 | } | |
103 | ||
104 | static char s35390a_hr2reg(struct s35390a *s35390a, int hour) | |
105 | { | |
106 | if (s35390a->twentyfourhour) | |
fe20ba70 | 107 | return bin2bcd(hour); |
c46288b0 BB |
108 | |
109 | if (hour < 12) | |
fe20ba70 | 110 | return bin2bcd(hour); |
c46288b0 | 111 | |
fe20ba70 | 112 | return 0x40 | bin2bcd(hour - 12); |
c46288b0 BB |
113 | } |
114 | ||
115 | static int s35390a_reg2hr(struct s35390a *s35390a, char reg) | |
116 | { | |
117 | unsigned hour; | |
118 | ||
119 | if (s35390a->twentyfourhour) | |
fe20ba70 | 120 | return bcd2bin(reg & 0x3f); |
c46288b0 | 121 | |
fe20ba70 | 122 | hour = bcd2bin(reg & 0x3f); |
c46288b0 BB |
123 | if (reg & 0x40) |
124 | hour += 12; | |
125 | ||
126 | return hour; | |
127 | } | |
128 | ||
129 | static int s35390a_set_datetime(struct i2c_client *client, struct rtc_time *tm) | |
130 | { | |
131 | struct s35390a *s35390a = i2c_get_clientdata(client); | |
132 | int i, err; | |
133 | char buf[7]; | |
134 | ||
135 | dev_dbg(&client->dev, "%s: tm is secs=%d, mins=%d, hours=%d mday=%d, " | |
136 | "mon=%d, year=%d, wday=%d\n", __func__, tm->tm_sec, | |
137 | tm->tm_min, tm->tm_hour, tm->tm_mday, tm->tm_mon, tm->tm_year, | |
138 | tm->tm_wday); | |
139 | ||
fe20ba70 AB |
140 | buf[S35390A_BYTE_YEAR] = bin2bcd(tm->tm_year - 100); |
141 | buf[S35390A_BYTE_MONTH] = bin2bcd(tm->tm_mon + 1); | |
142 | buf[S35390A_BYTE_DAY] = bin2bcd(tm->tm_mday); | |
143 | buf[S35390A_BYTE_WDAY] = bin2bcd(tm->tm_wday); | |
c46288b0 | 144 | buf[S35390A_BYTE_HOURS] = s35390a_hr2reg(s35390a, tm->tm_hour); |
fe20ba70 AB |
145 | buf[S35390A_BYTE_MINS] = bin2bcd(tm->tm_min); |
146 | buf[S35390A_BYTE_SECS] = bin2bcd(tm->tm_sec); | |
c46288b0 BB |
147 | |
148 | /* This chip expects the bits of each byte to be in reverse order */ | |
149 | for (i = 0; i < 7; ++i) | |
150 | buf[i] = bitrev8(buf[i]); | |
151 | ||
152 | err = s35390a_set_reg(s35390a, S35390A_CMD_TIME1, buf, sizeof(buf)); | |
153 | ||
154 | return err; | |
155 | } | |
156 | ||
157 | static int s35390a_get_datetime(struct i2c_client *client, struct rtc_time *tm) | |
158 | { | |
159 | struct s35390a *s35390a = i2c_get_clientdata(client); | |
160 | char buf[7]; | |
161 | int i, err; | |
162 | ||
163 | err = s35390a_get_reg(s35390a, S35390A_CMD_TIME1, buf, sizeof(buf)); | |
164 | if (err < 0) | |
165 | return err; | |
166 | ||
167 | /* This chip returns the bits of each byte in reverse order */ | |
168 | for (i = 0; i < 7; ++i) | |
169 | buf[i] = bitrev8(buf[i]); | |
170 | ||
fe20ba70 AB |
171 | tm->tm_sec = bcd2bin(buf[S35390A_BYTE_SECS]); |
172 | tm->tm_min = bcd2bin(buf[S35390A_BYTE_MINS]); | |
c46288b0 | 173 | tm->tm_hour = s35390a_reg2hr(s35390a, buf[S35390A_BYTE_HOURS]); |
fe20ba70 AB |
174 | tm->tm_wday = bcd2bin(buf[S35390A_BYTE_WDAY]); |
175 | tm->tm_mday = bcd2bin(buf[S35390A_BYTE_DAY]); | |
176 | tm->tm_mon = bcd2bin(buf[S35390A_BYTE_MONTH]) - 1; | |
177 | tm->tm_year = bcd2bin(buf[S35390A_BYTE_YEAR]) + 100; | |
c46288b0 BB |
178 | |
179 | dev_dbg(&client->dev, "%s: tm is secs=%d, mins=%d, hours=%d, mday=%d, " | |
180 | "mon=%d, year=%d, wday=%d\n", __func__, tm->tm_sec, | |
181 | tm->tm_min, tm->tm_hour, tm->tm_mday, tm->tm_mon, tm->tm_year, | |
182 | tm->tm_wday); | |
183 | ||
184 | return rtc_valid_tm(tm); | |
185 | } | |
186 | ||
187 | static int s35390a_rtc_read_time(struct device *dev, struct rtc_time *tm) | |
188 | { | |
189 | return s35390a_get_datetime(to_i2c_client(dev), tm); | |
190 | } | |
191 | ||
192 | static int s35390a_rtc_set_time(struct device *dev, struct rtc_time *tm) | |
193 | { | |
194 | return s35390a_set_datetime(to_i2c_client(dev), tm); | |
195 | } | |
196 | ||
197 | static const struct rtc_class_ops s35390a_rtc_ops = { | |
198 | .read_time = s35390a_rtc_read_time, | |
199 | .set_time = s35390a_rtc_set_time, | |
200 | }; | |
201 | ||
202 | static struct i2c_driver s35390a_driver; | |
203 | ||
d2653e92 JD |
204 | static int s35390a_probe(struct i2c_client *client, |
205 | const struct i2c_device_id *id) | |
c46288b0 BB |
206 | { |
207 | int err; | |
208 | unsigned int i; | |
209 | struct s35390a *s35390a; | |
210 | struct rtc_time tm; | |
211 | char buf[1]; | |
212 | ||
213 | if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) { | |
214 | err = -ENODEV; | |
215 | goto exit; | |
216 | } | |
217 | ||
218 | s35390a = kzalloc(sizeof(struct s35390a), GFP_KERNEL); | |
219 | if (!s35390a) { | |
220 | err = -ENOMEM; | |
221 | goto exit; | |
222 | } | |
223 | ||
224 | s35390a->client[0] = client; | |
225 | i2c_set_clientdata(client, s35390a); | |
226 | ||
227 | /* This chip uses multiple addresses, use dummy devices for them */ | |
228 | for (i = 1; i < 8; ++i) { | |
229 | s35390a->client[i] = i2c_new_dummy(client->adapter, | |
60b129d7 | 230 | client->addr + i); |
c46288b0 BB |
231 | if (!s35390a->client[i]) { |
232 | dev_err(&client->dev, "Address %02x unavailable\n", | |
233 | client->addr + i); | |
234 | err = -EBUSY; | |
235 | goto exit_dummy; | |
236 | } | |
237 | } | |
238 | ||
239 | err = s35390a_reset(s35390a); | |
240 | if (err < 0) { | |
241 | dev_err(&client->dev, "error resetting chip\n"); | |
242 | goto exit_dummy; | |
243 | } | |
244 | ||
245 | err = s35390a_disable_test_mode(s35390a); | |
246 | if (err < 0) { | |
247 | dev_err(&client->dev, "error disabling test mode\n"); | |
248 | goto exit_dummy; | |
249 | } | |
250 | ||
251 | err = s35390a_get_reg(s35390a, S35390A_CMD_STATUS1, buf, sizeof(buf)); | |
252 | if (err < 0) { | |
253 | dev_err(&client->dev, "error checking 12/24 hour mode\n"); | |
254 | goto exit_dummy; | |
255 | } | |
256 | if (buf[0] & S35390A_FLAG_24H) | |
257 | s35390a->twentyfourhour = 1; | |
258 | else | |
259 | s35390a->twentyfourhour = 0; | |
260 | ||
261 | if (s35390a_get_datetime(client, &tm) < 0) | |
262 | dev_warn(&client->dev, "clock needs to be set\n"); | |
263 | ||
264 | s35390a->rtc = rtc_device_register(s35390a_driver.driver.name, | |
265 | &client->dev, &s35390a_rtc_ops, THIS_MODULE); | |
266 | ||
267 | if (IS_ERR(s35390a->rtc)) { | |
268 | err = PTR_ERR(s35390a->rtc); | |
269 | goto exit_dummy; | |
270 | } | |
271 | return 0; | |
272 | ||
273 | exit_dummy: | |
274 | for (i = 1; i < 8; ++i) | |
275 | if (s35390a->client[i]) | |
276 | i2c_unregister_device(s35390a->client[i]); | |
277 | kfree(s35390a); | |
c46288b0 BB |
278 | |
279 | exit: | |
280 | return err; | |
281 | } | |
282 | ||
283 | static int s35390a_remove(struct i2c_client *client) | |
284 | { | |
285 | unsigned int i; | |
286 | ||
287 | struct s35390a *s35390a = i2c_get_clientdata(client); | |
288 | for (i = 1; i < 8; ++i) | |
289 | if (s35390a->client[i]) | |
290 | i2c_unregister_device(s35390a->client[i]); | |
291 | ||
292 | rtc_device_unregister(s35390a->rtc); | |
293 | kfree(s35390a); | |
c46288b0 BB |
294 | |
295 | return 0; | |
296 | } | |
297 | ||
298 | static struct i2c_driver s35390a_driver = { | |
299 | .driver = { | |
300 | .name = "rtc-s35390a", | |
301 | }, | |
302 | .probe = s35390a_probe, | |
303 | .remove = s35390a_remove, | |
3760f736 | 304 | .id_table = s35390a_id, |
c46288b0 BB |
305 | }; |
306 | ||
0abc9201 | 307 | module_i2c_driver(s35390a_driver); |
c46288b0 BB |
308 | |
309 | MODULE_AUTHOR("Byron Bradley <byron.bbradley@gmail.com>"); | |
310 | MODULE_DESCRIPTION("S35390A RTC driver"); | |
311 | MODULE_LICENSE("GPL"); |