Commit | Line | Data |
---|---|---|
d6c7428f RF |
1 | /* |
2 | * An I2C driver for the Intersil ISL 12022 | |
3 | * | |
4 | * Author: Roman Fietze <roman.fietze@telemotive.de> | |
5 | * | |
6 | * Based on the Philips PCF8563 RTC | |
7 | * by Alessandro Zummo <a.zummo@towertech.it>. | |
8 | * | |
9 | * This program is free software; you can redistribute it and/or | |
10 | * modify it under the terms of the GNU General Public License version | |
11 | * 2 as published by the Free Software Foundation. | |
12 | */ | |
13 | ||
14 | #include <linux/i2c.h> | |
15 | #include <linux/bcd.h> | |
16 | #include <linux/rtc.h> | |
17 | #include <linux/slab.h> | |
2113852b | 18 | #include <linux/module.h> |
d6c7428f RF |
19 | |
20 | #define DRV_VERSION "0.1" | |
21 | ||
22 | /* ISL register offsets */ | |
23 | #define ISL12022_REG_SC 0x00 | |
24 | #define ISL12022_REG_MN 0x01 | |
25 | #define ISL12022_REG_HR 0x02 | |
26 | #define ISL12022_REG_DT 0x03 | |
27 | #define ISL12022_REG_MO 0x04 | |
28 | #define ISL12022_REG_YR 0x05 | |
29 | #define ISL12022_REG_DW 0x06 | |
30 | ||
31 | #define ISL12022_REG_SR 0x07 | |
32 | #define ISL12022_REG_INT 0x08 | |
33 | ||
34 | /* ISL register bits */ | |
35 | #define ISL12022_HR_MIL (1 << 7) /* military or 24 hour time */ | |
36 | ||
37 | #define ISL12022_SR_LBAT85 (1 << 2) | |
38 | #define ISL12022_SR_LBAT75 (1 << 1) | |
39 | ||
40 | #define ISL12022_INT_WRTC (1 << 6) | |
41 | ||
42 | ||
43 | static struct i2c_driver isl12022_driver; | |
44 | ||
45 | struct isl12022 { | |
46 | struct rtc_device *rtc; | |
47 | ||
48 | bool write_enabled; /* true if write enable is set */ | |
49 | }; | |
50 | ||
51 | ||
52 | static int isl12022_read_regs(struct i2c_client *client, uint8_t reg, | |
53 | uint8_t *data, size_t n) | |
54 | { | |
55 | struct i2c_msg msgs[] = { | |
56 | { | |
57 | .addr = client->addr, | |
58 | .flags = 0, | |
59 | .len = 1, | |
60 | .buf = data | |
61 | }, /* setup read ptr */ | |
62 | { | |
63 | .addr = client->addr, | |
64 | .flags = I2C_M_RD, | |
65 | .len = n, | |
66 | .buf = data | |
67 | } | |
68 | }; | |
69 | ||
70 | int ret; | |
71 | ||
72 | data[0] = reg; | |
73 | ret = i2c_transfer(client->adapter, msgs, ARRAY_SIZE(msgs)); | |
74 | if (ret != ARRAY_SIZE(msgs)) { | |
75 | dev_err(&client->dev, "%s: read error, ret=%d\n", | |
76 | __func__, ret); | |
77 | return -EIO; | |
78 | } | |
79 | ||
80 | return 0; | |
81 | } | |
82 | ||
83 | ||
84 | static int isl12022_write_reg(struct i2c_client *client, | |
85 | uint8_t reg, uint8_t val) | |
86 | { | |
87 | uint8_t data[2] = { reg, val }; | |
88 | int err; | |
89 | ||
90 | err = i2c_master_send(client, data, sizeof(data)); | |
91 | if (err != sizeof(data)) { | |
92 | dev_err(&client->dev, | |
93 | "%s: err=%d addr=%02x, data=%02x\n", | |
94 | __func__, err, data[0], data[1]); | |
95 | return -EIO; | |
96 | } | |
97 | ||
98 | return 0; | |
99 | } | |
100 | ||
101 | ||
102 | /* | |
103 | * In the routines that deal directly with the isl12022 hardware, we use | |
104 | * rtc_time -- month 0-11, hour 0-23, yr = calendar year-epoch. | |
105 | */ | |
106 | static int isl12022_get_datetime(struct i2c_client *client, struct rtc_time *tm) | |
107 | { | |
108 | uint8_t buf[ISL12022_REG_INT + 1]; | |
109 | int ret; | |
110 | ||
111 | ret = isl12022_read_regs(client, ISL12022_REG_SC, buf, sizeof(buf)); | |
112 | if (ret) | |
113 | return ret; | |
114 | ||
115 | if (buf[ISL12022_REG_SR] & (ISL12022_SR_LBAT85 | ISL12022_SR_LBAT75)) { | |
116 | dev_warn(&client->dev, | |
117 | "voltage dropped below %u%%, " | |
118 | "date and time is not reliable.\n", | |
119 | buf[ISL12022_REG_SR] & ISL12022_SR_LBAT85 ? 85 : 75); | |
120 | } | |
121 | ||
122 | dev_dbg(&client->dev, | |
123 | "%s: raw data is sec=%02x, min=%02x, hr=%02x, " | |
124 | "mday=%02x, mon=%02x, year=%02x, wday=%02x, " | |
125 | "sr=%02x, int=%02x", | |
126 | __func__, | |
127 | buf[ISL12022_REG_SC], | |
128 | buf[ISL12022_REG_MN], | |
129 | buf[ISL12022_REG_HR], | |
130 | buf[ISL12022_REG_DT], | |
131 | buf[ISL12022_REG_MO], | |
132 | buf[ISL12022_REG_YR], | |
133 | buf[ISL12022_REG_DW], | |
134 | buf[ISL12022_REG_SR], | |
135 | buf[ISL12022_REG_INT]); | |
136 | ||
137 | tm->tm_sec = bcd2bin(buf[ISL12022_REG_SC] & 0x7F); | |
138 | tm->tm_min = bcd2bin(buf[ISL12022_REG_MN] & 0x7F); | |
139 | tm->tm_hour = bcd2bin(buf[ISL12022_REG_HR] & 0x3F); | |
140 | tm->tm_mday = bcd2bin(buf[ISL12022_REG_DT] & 0x3F); | |
141 | tm->tm_wday = buf[ISL12022_REG_DW] & 0x07; | |
142 | tm->tm_mon = bcd2bin(buf[ISL12022_REG_MO] & 0x1F) - 1; | |
143 | tm->tm_year = bcd2bin(buf[ISL12022_REG_YR]) + 100; | |
144 | ||
145 | dev_dbg(&client->dev, "%s: secs=%d, mins=%d, hours=%d, " | |
146 | "mday=%d, mon=%d, year=%d, wday=%d\n", | |
147 | __func__, | |
148 | tm->tm_sec, tm->tm_min, tm->tm_hour, | |
149 | tm->tm_mday, tm->tm_mon, tm->tm_year, tm->tm_wday); | |
150 | ||
151 | /* The clock can give out invalid datetime, but we cannot return | |
152 | * -EINVAL otherwise hwclock will refuse to set the time on bootup. */ | |
153 | if (rtc_valid_tm(tm) < 0) | |
154 | dev_err(&client->dev, "retrieved date and time is invalid.\n"); | |
155 | ||
156 | return 0; | |
157 | } | |
158 | ||
159 | static int isl12022_set_datetime(struct i2c_client *client, struct rtc_time *tm) | |
160 | { | |
161 | struct isl12022 *isl12022 = i2c_get_clientdata(client); | |
162 | size_t i; | |
163 | int ret; | |
164 | uint8_t buf[ISL12022_REG_DW + 1]; | |
165 | ||
166 | dev_dbg(&client->dev, "%s: secs=%d, mins=%d, hours=%d, " | |
167 | "mday=%d, mon=%d, year=%d, wday=%d\n", | |
168 | __func__, | |
169 | tm->tm_sec, tm->tm_min, tm->tm_hour, | |
170 | tm->tm_mday, tm->tm_mon, tm->tm_year, tm->tm_wday); | |
171 | ||
172 | if (!isl12022->write_enabled) { | |
173 | ||
174 | ret = isl12022_read_regs(client, ISL12022_REG_INT, buf, 1); | |
175 | if (ret) | |
176 | return ret; | |
177 | ||
178 | /* Check if WRTC (write rtc enable) is set factory default is | |
179 | * 0 (not set) */ | |
180 | if (!(buf[0] & ISL12022_INT_WRTC)) { | |
181 | dev_info(&client->dev, | |
182 | "init write enable and 24 hour format\n"); | |
183 | ||
184 | /* Set the write enable bit. */ | |
185 | ret = isl12022_write_reg(client, | |
186 | ISL12022_REG_INT, | |
187 | buf[0] | ISL12022_INT_WRTC); | |
188 | if (ret) | |
189 | return ret; | |
190 | ||
191 | /* Write to any RTC register to start RTC, we use the | |
192 | * HR register, setting the MIL bit to use the 24 hour | |
193 | * format. */ | |
194 | ret = isl12022_read_regs(client, ISL12022_REG_HR, | |
195 | buf, 1); | |
196 | if (ret) | |
197 | return ret; | |
198 | ||
199 | ret = isl12022_write_reg(client, | |
200 | ISL12022_REG_HR, | |
201 | buf[0] | ISL12022_HR_MIL); | |
202 | if (ret) | |
203 | return ret; | |
204 | } | |
205 | ||
206 | isl12022->write_enabled = 1; | |
207 | } | |
208 | ||
209 | /* hours, minutes and seconds */ | |
210 | buf[ISL12022_REG_SC] = bin2bcd(tm->tm_sec); | |
211 | buf[ISL12022_REG_MN] = bin2bcd(tm->tm_min); | |
6d23b258 | 212 | buf[ISL12022_REG_HR] = bin2bcd(tm->tm_hour) | ISL12022_HR_MIL; |
d6c7428f RF |
213 | |
214 | buf[ISL12022_REG_DT] = bin2bcd(tm->tm_mday); | |
215 | ||
216 | /* month, 1 - 12 */ | |
217 | buf[ISL12022_REG_MO] = bin2bcd(tm->tm_mon + 1); | |
218 | ||
219 | /* year and century */ | |
220 | buf[ISL12022_REG_YR] = bin2bcd(tm->tm_year % 100); | |
221 | ||
222 | buf[ISL12022_REG_DW] = tm->tm_wday & 0x07; | |
223 | ||
224 | /* write register's data */ | |
225 | for (i = 0; i < ARRAY_SIZE(buf); i++) { | |
226 | ret = isl12022_write_reg(client, ISL12022_REG_SC + i, | |
227 | buf[ISL12022_REG_SC + i]); | |
228 | if (ret) | |
229 | return -EIO; | |
230 | }; | |
231 | ||
232 | return 0; | |
233 | } | |
234 | ||
235 | static int isl12022_rtc_read_time(struct device *dev, struct rtc_time *tm) | |
236 | { | |
237 | return isl12022_get_datetime(to_i2c_client(dev), tm); | |
238 | } | |
239 | ||
240 | static int isl12022_rtc_set_time(struct device *dev, struct rtc_time *tm) | |
241 | { | |
242 | return isl12022_set_datetime(to_i2c_client(dev), tm); | |
243 | } | |
244 | ||
245 | static const struct rtc_class_ops isl12022_rtc_ops = { | |
246 | .read_time = isl12022_rtc_read_time, | |
247 | .set_time = isl12022_rtc_set_time, | |
248 | }; | |
249 | ||
250 | static int isl12022_probe(struct i2c_client *client, | |
251 | const struct i2c_device_id *id) | |
252 | { | |
253 | struct isl12022 *isl12022; | |
254 | ||
255 | int ret = 0; | |
256 | ||
257 | if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) | |
258 | return -ENODEV; | |
259 | ||
260 | isl12022 = kzalloc(sizeof(struct isl12022), GFP_KERNEL); | |
261 | if (!isl12022) | |
262 | return -ENOMEM; | |
263 | ||
264 | dev_dbg(&client->dev, "chip found, driver version " DRV_VERSION "\n"); | |
265 | ||
266 | i2c_set_clientdata(client, isl12022); | |
267 | ||
268 | isl12022->rtc = rtc_device_register(isl12022_driver.driver.name, | |
269 | &client->dev, | |
270 | &isl12022_rtc_ops, | |
271 | THIS_MODULE); | |
272 | ||
273 | if (IS_ERR(isl12022->rtc)) { | |
274 | ret = PTR_ERR(isl12022->rtc); | |
275 | goto exit_kfree; | |
276 | } | |
277 | ||
278 | return 0; | |
279 | ||
280 | exit_kfree: | |
281 | kfree(isl12022); | |
282 | ||
283 | return ret; | |
284 | } | |
285 | ||
286 | static int isl12022_remove(struct i2c_client *client) | |
287 | { | |
288 | struct isl12022 *isl12022 = i2c_get_clientdata(client); | |
289 | ||
290 | rtc_device_unregister(isl12022->rtc); | |
291 | kfree(isl12022); | |
292 | ||
293 | return 0; | |
294 | } | |
295 | ||
296 | static const struct i2c_device_id isl12022_id[] = { | |
297 | { "isl12022", 0 }, | |
298 | { "rtc8564", 0 }, | |
299 | { } | |
300 | }; | |
301 | MODULE_DEVICE_TABLE(i2c, isl12022_id); | |
302 | ||
303 | static struct i2c_driver isl12022_driver = { | |
304 | .driver = { | |
305 | .name = "rtc-isl12022", | |
306 | }, | |
307 | .probe = isl12022_probe, | |
308 | .remove = isl12022_remove, | |
309 | .id_table = isl12022_id, | |
310 | }; | |
311 | ||
0abc9201 | 312 | module_i2c_driver(isl12022_driver); |
d6c7428f RF |
313 | |
314 | MODULE_AUTHOR("roman.fietze@telemotive.de"); | |
315 | MODULE_DESCRIPTION("ISL 12022 RTC driver"); | |
316 | MODULE_LICENSE("GPL"); | |
317 | MODULE_VERSION(DRV_VERSION); |