Commit | Line | Data |
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4d61ff6b PDM |
1 | /* |
2 | * A driver for the I2C members of the Abracon AB x8xx RTC family, | |
3 | * and compatible: AB 1805 and AB 0805 | |
4 | * | |
5 | * Copyright 2014-2015 Macq S.A. | |
6 | * | |
7 | * Author: Philippe De Muyter <phdm@macqel.be> | |
8 | * Author: Alexandre Belloni <alexandre.belloni@free-electrons.com> | |
9 | * | |
10 | * This program is free software; you can redistribute it and/or modify | |
11 | * it under the terms of the GNU General Public License version 2 as | |
12 | * published by the Free Software Foundation. | |
13 | * | |
14 | */ | |
15 | ||
16 | #include <linux/bcd.h> | |
17 | #include <linux/i2c.h> | |
18 | #include <linux/module.h> | |
19 | #include <linux/rtc.h> | |
20 | ||
21 | #define ABX8XX_REG_HTH 0x00 | |
22 | #define ABX8XX_REG_SC 0x01 | |
23 | #define ABX8XX_REG_MN 0x02 | |
24 | #define ABX8XX_REG_HR 0x03 | |
25 | #define ABX8XX_REG_DA 0x04 | |
26 | #define ABX8XX_REG_MO 0x05 | |
27 | #define ABX8XX_REG_YR 0x06 | |
28 | #define ABX8XX_REG_WD 0x07 | |
29 | ||
718a820a AB |
30 | #define ABX8XX_REG_AHTH 0x08 |
31 | #define ABX8XX_REG_ASC 0x09 | |
32 | #define ABX8XX_REG_AMN 0x0a | |
33 | #define ABX8XX_REG_AHR 0x0b | |
34 | #define ABX8XX_REG_ADA 0x0c | |
35 | #define ABX8XX_REG_AMO 0x0d | |
36 | #define ABX8XX_REG_AWD 0x0e | |
37 | ||
38 | #define ABX8XX_REG_STATUS 0x0f | |
39 | #define ABX8XX_STATUS_AF BIT(2) | |
40 | ||
4d61ff6b | 41 | #define ABX8XX_REG_CTRL1 0x10 |
5f1b2f77 | 42 | #define ABX8XX_CTRL_WRITE BIT(0) |
718a820a | 43 | #define ABX8XX_CTRL_ARST BIT(2) |
4d61ff6b PDM |
44 | #define ABX8XX_CTRL_12_24 BIT(6) |
45 | ||
718a820a AB |
46 | #define ABX8XX_REG_IRQ 0x12 |
47 | #define ABX8XX_IRQ_AIE BIT(2) | |
48 | #define ABX8XX_IRQ_IM_1_4 (0x3 << 5) | |
49 | ||
50 | #define ABX8XX_REG_CD_TIMER_CTL 0x18 | |
51 | ||
4d61ff6b PDM |
52 | #define ABX8XX_REG_CFG_KEY 0x1f |
53 | #define ABX8XX_CFG_KEY_MISC 0x9d | |
54 | ||
55 | #define ABX8XX_REG_ID0 0x28 | |
56 | ||
57 | #define ABX8XX_REG_TRICKLE 0x20 | |
58 | #define ABX8XX_TRICKLE_CHARGE_ENABLE 0xa0 | |
59 | #define ABX8XX_TRICKLE_STANDARD_DIODE 0x8 | |
60 | #define ABX8XX_TRICKLE_SCHOTTKY_DIODE 0x4 | |
61 | ||
62 | static u8 trickle_resistors[] = {0, 3, 6, 11}; | |
63 | ||
64 | enum abx80x_chip {AB0801, AB0803, AB0804, AB0805, | |
65 | AB1801, AB1803, AB1804, AB1805, ABX80X}; | |
66 | ||
67 | struct abx80x_cap { | |
68 | u16 pn; | |
69 | bool has_tc; | |
70 | }; | |
71 | ||
72 | static struct abx80x_cap abx80x_caps[] = { | |
73 | [AB0801] = {.pn = 0x0801}, | |
74 | [AB0803] = {.pn = 0x0803}, | |
75 | [AB0804] = {.pn = 0x0804, .has_tc = true}, | |
76 | [AB0805] = {.pn = 0x0805, .has_tc = true}, | |
77 | [AB1801] = {.pn = 0x1801}, | |
78 | [AB1803] = {.pn = 0x1803}, | |
79 | [AB1804] = {.pn = 0x1804, .has_tc = true}, | |
80 | [AB1805] = {.pn = 0x1805, .has_tc = true}, | |
81 | [ABX80X] = {.pn = 0} | |
82 | }; | |
83 | ||
4d61ff6b PDM |
84 | static int abx80x_enable_trickle_charger(struct i2c_client *client, |
85 | u8 trickle_cfg) | |
86 | { | |
87 | int err; | |
88 | ||
89 | /* | |
90 | * Write the configuration key register to enable access to the Trickle | |
91 | * register | |
92 | */ | |
93 | err = i2c_smbus_write_byte_data(client, ABX8XX_REG_CFG_KEY, | |
94 | ABX8XX_CFG_KEY_MISC); | |
95 | if (err < 0) { | |
96 | dev_err(&client->dev, "Unable to write configuration key\n"); | |
97 | return -EIO; | |
98 | } | |
99 | ||
100 | err = i2c_smbus_write_byte_data(client, ABX8XX_REG_TRICKLE, | |
101 | ABX8XX_TRICKLE_CHARGE_ENABLE | | |
102 | trickle_cfg); | |
103 | if (err < 0) { | |
104 | dev_err(&client->dev, "Unable to write trickle register\n"); | |
105 | return -EIO; | |
106 | } | |
107 | ||
108 | return 0; | |
109 | } | |
110 | ||
111 | static int abx80x_rtc_read_time(struct device *dev, struct rtc_time *tm) | |
112 | { | |
113 | struct i2c_client *client = to_i2c_client(dev); | |
114 | unsigned char buf[8]; | |
115 | int err; | |
116 | ||
117 | err = i2c_smbus_read_i2c_block_data(client, ABX8XX_REG_HTH, | |
118 | sizeof(buf), buf); | |
119 | if (err < 0) { | |
120 | dev_err(&client->dev, "Unable to read date\n"); | |
121 | return -EIO; | |
122 | } | |
123 | ||
124 | tm->tm_sec = bcd2bin(buf[ABX8XX_REG_SC] & 0x7F); | |
125 | tm->tm_min = bcd2bin(buf[ABX8XX_REG_MN] & 0x7F); | |
126 | tm->tm_hour = bcd2bin(buf[ABX8XX_REG_HR] & 0x3F); | |
127 | tm->tm_wday = buf[ABX8XX_REG_WD] & 0x7; | |
128 | tm->tm_mday = bcd2bin(buf[ABX8XX_REG_DA] & 0x3F); | |
129 | tm->tm_mon = bcd2bin(buf[ABX8XX_REG_MO] & 0x1F) - 1; | |
130 | tm->tm_year = bcd2bin(buf[ABX8XX_REG_YR]) + 100; | |
131 | ||
132 | err = rtc_valid_tm(tm); | |
133 | if (err < 0) | |
134 | dev_err(&client->dev, "retrieved date/time is not valid.\n"); | |
135 | ||
136 | return err; | |
137 | } | |
138 | ||
139 | static int abx80x_rtc_set_time(struct device *dev, struct rtc_time *tm) | |
140 | { | |
141 | struct i2c_client *client = to_i2c_client(dev); | |
142 | unsigned char buf[8]; | |
143 | int err; | |
144 | ||
145 | if (tm->tm_year < 100) | |
146 | return -EINVAL; | |
147 | ||
148 | buf[ABX8XX_REG_HTH] = 0; | |
149 | buf[ABX8XX_REG_SC] = bin2bcd(tm->tm_sec); | |
150 | buf[ABX8XX_REG_MN] = bin2bcd(tm->tm_min); | |
151 | buf[ABX8XX_REG_HR] = bin2bcd(tm->tm_hour); | |
152 | buf[ABX8XX_REG_DA] = bin2bcd(tm->tm_mday); | |
153 | buf[ABX8XX_REG_MO] = bin2bcd(tm->tm_mon + 1); | |
154 | buf[ABX8XX_REG_YR] = bin2bcd(tm->tm_year - 100); | |
155 | buf[ABX8XX_REG_WD] = tm->tm_wday; | |
156 | ||
157 | err = i2c_smbus_write_i2c_block_data(client, ABX8XX_REG_HTH, | |
158 | sizeof(buf), buf); | |
159 | if (err < 0) { | |
160 | dev_err(&client->dev, "Unable to write to date registers\n"); | |
161 | return -EIO; | |
162 | } | |
163 | ||
164 | return 0; | |
165 | } | |
166 | ||
718a820a AB |
167 | static irqreturn_t abx80x_handle_irq(int irq, void *dev_id) |
168 | { | |
169 | struct i2c_client *client = dev_id; | |
170 | struct rtc_device *rtc = i2c_get_clientdata(client); | |
171 | int status; | |
172 | ||
173 | status = i2c_smbus_read_byte_data(client, ABX8XX_REG_STATUS); | |
174 | if (status < 0) | |
175 | return IRQ_NONE; | |
176 | ||
177 | if (status & ABX8XX_STATUS_AF) | |
178 | rtc_update_irq(rtc, 1, RTC_AF | RTC_IRQF); | |
179 | ||
180 | i2c_smbus_write_byte_data(client, ABX8XX_REG_STATUS, 0); | |
181 | ||
182 | return IRQ_HANDLED; | |
183 | } | |
184 | ||
185 | static int abx80x_read_alarm(struct device *dev, struct rtc_wkalrm *t) | |
186 | { | |
187 | struct i2c_client *client = to_i2c_client(dev); | |
188 | unsigned char buf[7]; | |
189 | ||
190 | int irq_mask, err; | |
191 | ||
192 | if (client->irq <= 0) | |
193 | return -EINVAL; | |
194 | ||
195 | err = i2c_smbus_read_i2c_block_data(client, ABX8XX_REG_ASC, | |
196 | sizeof(buf), buf); | |
197 | if (err) | |
198 | return err; | |
199 | ||
200 | irq_mask = i2c_smbus_read_byte_data(client, ABX8XX_REG_IRQ); | |
201 | if (irq_mask < 0) | |
202 | return irq_mask; | |
203 | ||
204 | t->time.tm_sec = bcd2bin(buf[0] & 0x7F); | |
205 | t->time.tm_min = bcd2bin(buf[1] & 0x7F); | |
206 | t->time.tm_hour = bcd2bin(buf[2] & 0x3F); | |
207 | t->time.tm_mday = bcd2bin(buf[3] & 0x3F); | |
208 | t->time.tm_mon = bcd2bin(buf[4] & 0x1F) - 1; | |
209 | t->time.tm_wday = buf[5] & 0x7; | |
210 | ||
211 | t->enabled = !!(irq_mask & ABX8XX_IRQ_AIE); | |
212 | t->pending = (buf[6] & ABX8XX_STATUS_AF) && t->enabled; | |
213 | ||
214 | return err; | |
215 | } | |
216 | ||
217 | static int abx80x_set_alarm(struct device *dev, struct rtc_wkalrm *t) | |
218 | { | |
219 | struct i2c_client *client = to_i2c_client(dev); | |
220 | u8 alarm[6]; | |
221 | int err; | |
222 | ||
223 | if (client->irq <= 0) | |
224 | return -EINVAL; | |
225 | ||
226 | alarm[0] = 0x0; | |
227 | alarm[1] = bin2bcd(t->time.tm_sec); | |
228 | alarm[2] = bin2bcd(t->time.tm_min); | |
229 | alarm[3] = bin2bcd(t->time.tm_hour); | |
230 | alarm[4] = bin2bcd(t->time.tm_mday); | |
231 | alarm[5] = bin2bcd(t->time.tm_mon + 1); | |
232 | ||
233 | err = i2c_smbus_write_i2c_block_data(client, ABX8XX_REG_AHTH, | |
234 | sizeof(alarm), alarm); | |
235 | if (err < 0) { | |
236 | dev_err(&client->dev, "Unable to write alarm registers\n"); | |
237 | return -EIO; | |
238 | } | |
239 | ||
240 | if (t->enabled) { | |
241 | err = i2c_smbus_write_byte_data(client, ABX8XX_REG_IRQ, | |
242 | (ABX8XX_IRQ_IM_1_4 | | |
243 | ABX8XX_IRQ_AIE)); | |
244 | if (err) | |
245 | return err; | |
246 | } | |
247 | ||
248 | return 0; | |
249 | } | |
250 | ||
251 | static int abx80x_alarm_irq_enable(struct device *dev, unsigned int enabled) | |
252 | { | |
253 | struct i2c_client *client = to_i2c_client(dev); | |
254 | int err; | |
255 | ||
256 | if (enabled) | |
257 | err = i2c_smbus_write_byte_data(client, ABX8XX_REG_IRQ, | |
258 | (ABX8XX_IRQ_IM_1_4 | | |
259 | ABX8XX_IRQ_AIE)); | |
260 | else | |
261 | err = i2c_smbus_write_byte_data(client, ABX8XX_REG_IRQ, | |
262 | ABX8XX_IRQ_IM_1_4); | |
263 | return err; | |
264 | } | |
265 | ||
4d61ff6b PDM |
266 | static const struct rtc_class_ops abx80x_rtc_ops = { |
267 | .read_time = abx80x_rtc_read_time, | |
268 | .set_time = abx80x_rtc_set_time, | |
718a820a AB |
269 | .read_alarm = abx80x_read_alarm, |
270 | .set_alarm = abx80x_set_alarm, | |
271 | .alarm_irq_enable = abx80x_alarm_irq_enable, | |
4d61ff6b PDM |
272 | }; |
273 | ||
274 | static int abx80x_dt_trickle_cfg(struct device_node *np) | |
275 | { | |
276 | const char *diode; | |
277 | int trickle_cfg = 0; | |
278 | int i, ret; | |
279 | u32 tmp; | |
280 | ||
281 | ret = of_property_read_string(np, "abracon,tc-diode", &diode); | |
282 | if (ret) | |
283 | return ret; | |
284 | ||
285 | if (!strcmp(diode, "standard")) | |
286 | trickle_cfg |= ABX8XX_TRICKLE_STANDARD_DIODE; | |
287 | else if (!strcmp(diode, "schottky")) | |
288 | trickle_cfg |= ABX8XX_TRICKLE_SCHOTTKY_DIODE; | |
289 | else | |
290 | return -EINVAL; | |
291 | ||
292 | ret = of_property_read_u32(np, "abracon,tc-resistor", &tmp); | |
293 | if (ret) | |
294 | return ret; | |
295 | ||
296 | for (i = 0; i < sizeof(trickle_resistors); i++) | |
297 | if (trickle_resistors[i] == tmp) | |
298 | break; | |
299 | ||
300 | if (i == sizeof(trickle_resistors)) | |
301 | return -EINVAL; | |
302 | ||
303 | return (trickle_cfg | i); | |
304 | } | |
305 | ||
306 | static int abx80x_probe(struct i2c_client *client, | |
307 | const struct i2c_device_id *id) | |
308 | { | |
309 | struct device_node *np = client->dev.of_node; | |
310 | struct rtc_device *rtc; | |
311 | int i, data, err, trickle_cfg = -EINVAL; | |
312 | char buf[7]; | |
313 | unsigned int part = id->driver_data; | |
314 | unsigned int partnumber; | |
315 | unsigned int majrev, minrev; | |
316 | unsigned int lot; | |
317 | unsigned int wafer; | |
318 | unsigned int uid; | |
319 | ||
320 | if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) | |
321 | return -ENODEV; | |
322 | ||
323 | err = i2c_smbus_read_i2c_block_data(client, ABX8XX_REG_ID0, | |
324 | sizeof(buf), buf); | |
325 | if (err < 0) { | |
326 | dev_err(&client->dev, "Unable to read partnumber\n"); | |
327 | return -EIO; | |
328 | } | |
329 | ||
330 | partnumber = (buf[0] << 8) | buf[1]; | |
331 | majrev = buf[2] >> 3; | |
332 | minrev = buf[2] & 0x7; | |
333 | lot = ((buf[4] & 0x80) << 2) | ((buf[6] & 0x80) << 1) | buf[3]; | |
334 | uid = ((buf[4] & 0x7f) << 8) | buf[5]; | |
335 | wafer = (buf[6] & 0x7c) >> 2; | |
336 | dev_info(&client->dev, "model %04x, revision %u.%u, lot %x, wafer %x, uid %x\n", | |
337 | partnumber, majrev, minrev, lot, wafer, uid); | |
338 | ||
339 | data = i2c_smbus_read_byte_data(client, ABX8XX_REG_CTRL1); | |
340 | if (data < 0) { | |
341 | dev_err(&client->dev, "Unable to read control register\n"); | |
342 | return -EIO; | |
343 | } | |
344 | ||
345 | err = i2c_smbus_write_byte_data(client, ABX8XX_REG_CTRL1, | |
718a820a AB |
346 | ((data & ~(ABX8XX_CTRL_12_24 | |
347 | ABX8XX_CTRL_ARST)) | | |
4d61ff6b PDM |
348 | ABX8XX_CTRL_WRITE)); |
349 | if (err < 0) { | |
350 | dev_err(&client->dev, "Unable to write control register\n"); | |
351 | return -EIO; | |
352 | } | |
353 | ||
354 | /* part autodetection */ | |
355 | if (part == ABX80X) { | |
356 | for (i = 0; abx80x_caps[i].pn; i++) | |
357 | if (partnumber == abx80x_caps[i].pn) | |
358 | break; | |
359 | if (abx80x_caps[i].pn == 0) { | |
360 | dev_err(&client->dev, "Unknown part: %04x\n", | |
361 | partnumber); | |
362 | return -EINVAL; | |
363 | } | |
364 | part = i; | |
365 | } | |
366 | ||
367 | if (partnumber != abx80x_caps[part].pn) { | |
368 | dev_err(&client->dev, "partnumber mismatch %04x != %04x\n", | |
369 | partnumber, abx80x_caps[part].pn); | |
370 | return -EINVAL; | |
371 | } | |
372 | ||
373 | if (np && abx80x_caps[part].has_tc) | |
374 | trickle_cfg = abx80x_dt_trickle_cfg(np); | |
375 | ||
376 | if (trickle_cfg > 0) { | |
377 | dev_info(&client->dev, "Enabling trickle charger: %02x\n", | |
378 | trickle_cfg); | |
379 | abx80x_enable_trickle_charger(client, trickle_cfg); | |
380 | } | |
381 | ||
718a820a AB |
382 | err = i2c_smbus_write_byte_data(client, ABX8XX_REG_CD_TIMER_CTL, |
383 | BIT(2)); | |
384 | if (err) | |
385 | return err; | |
386 | ||
387 | rtc = devm_rtc_device_register(&client->dev, "abx8xx", | |
4d61ff6b PDM |
388 | &abx80x_rtc_ops, THIS_MODULE); |
389 | ||
390 | if (IS_ERR(rtc)) | |
391 | return PTR_ERR(rtc); | |
392 | ||
393 | i2c_set_clientdata(client, rtc); | |
394 | ||
718a820a AB |
395 | if (client->irq > 0) { |
396 | dev_info(&client->dev, "IRQ %d supplied\n", client->irq); | |
397 | err = devm_request_threaded_irq(&client->dev, client->irq, NULL, | |
398 | abx80x_handle_irq, | |
399 | IRQF_SHARED | IRQF_ONESHOT, | |
400 | "abx8xx", | |
401 | client); | |
402 | if (err) { | |
403 | dev_err(&client->dev, "unable to request IRQ, alarms disabled\n"); | |
404 | client->irq = 0; | |
405 | } | |
406 | } | |
407 | ||
4d61ff6b PDM |
408 | return 0; |
409 | } | |
410 | ||
411 | static int abx80x_remove(struct i2c_client *client) | |
412 | { | |
413 | return 0; | |
414 | } | |
415 | ||
416 | static const struct i2c_device_id abx80x_id[] = { | |
417 | { "abx80x", ABX80X }, | |
418 | { "ab0801", AB0801 }, | |
419 | { "ab0803", AB0803 }, | |
420 | { "ab0804", AB0804 }, | |
421 | { "ab0805", AB0805 }, | |
422 | { "ab1801", AB1801 }, | |
423 | { "ab1803", AB1803 }, | |
424 | { "ab1804", AB1804 }, | |
425 | { "ab1805", AB1805 }, | |
fca733a1 | 426 | { "rv1805", AB1805 }, |
4d61ff6b PDM |
427 | { } |
428 | }; | |
429 | MODULE_DEVICE_TABLE(i2c, abx80x_id); | |
430 | ||
431 | static struct i2c_driver abx80x_driver = { | |
432 | .driver = { | |
433 | .name = "rtc-abx80x", | |
434 | }, | |
435 | .probe = abx80x_probe, | |
436 | .remove = abx80x_remove, | |
437 | .id_table = abx80x_id, | |
438 | }; | |
439 | ||
440 | module_i2c_driver(abx80x_driver); | |
441 | ||
442 | MODULE_AUTHOR("Philippe De Muyter <phdm@macqel.be>"); | |
443 | MODULE_AUTHOR("Alexandre Belloni <alexandre.belloni@free-electrons.com>"); | |
444 | MODULE_DESCRIPTION("Abracon ABX80X RTC driver"); | |
445 | MODULE_LICENSE("GPL v2"); |