Loading...
1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * Copyright (C) 2012 Avionic Design GmbH
4 */
5
6#include <linux/bcd.h>
7#include <linux/i2c.h>
8#include <linux/module.h>
9#include <linux/rtc.h>
10#include <linux/of.h>
11
12#define DRIVER_NAME "rtc-pcf8523"
13
14#define REG_CONTROL1 0x00
15#define REG_CONTROL1_CAP_SEL (1 << 7)
16#define REG_CONTROL1_STOP (1 << 5)
17
18#define REG_CONTROL3 0x02
19#define REG_CONTROL3_PM_BLD (1 << 7) /* battery low detection disabled */
20#define REG_CONTROL3_PM_VDD (1 << 6) /* switch-over disabled */
21#define REG_CONTROL3_PM_DSM (1 << 5) /* direct switching mode */
22#define REG_CONTROL3_PM_MASK 0xe0
23#define REG_CONTROL3_BLF (1 << 2) /* battery low bit, read-only */
24
25#define REG_SECONDS 0x03
26#define REG_SECONDS_OS (1 << 7)
27
28#define REG_MINUTES 0x04
29#define REG_HOURS 0x05
30#define REG_DAYS 0x06
31#define REG_WEEKDAYS 0x07
32#define REG_MONTHS 0x08
33#define REG_YEARS 0x09
34
35#define REG_OFFSET 0x0e
36#define REG_OFFSET_MODE BIT(7)
37
38struct pcf8523 {
39 struct rtc_device *rtc;
40};
41
42static int pcf8523_read(struct i2c_client *client, u8 reg, u8 *valuep)
43{
44 struct i2c_msg msgs[2];
45 u8 value = 0;
46 int err;
47
48 msgs[0].addr = client->addr;
49 msgs[0].flags = 0;
50 msgs[0].len = sizeof(reg);
51 msgs[0].buf = ®
52
53 msgs[1].addr = client->addr;
54 msgs[1].flags = I2C_M_RD;
55 msgs[1].len = sizeof(value);
56 msgs[1].buf = &value;
57
58 err = i2c_transfer(client->adapter, msgs, ARRAY_SIZE(msgs));
59 if (err < 0)
60 return err;
61
62 *valuep = value;
63
64 return 0;
65}
66
67static int pcf8523_write(struct i2c_client *client, u8 reg, u8 value)
68{
69 u8 buffer[2] = { reg, value };
70 struct i2c_msg msg;
71 int err;
72
73 msg.addr = client->addr;
74 msg.flags = 0;
75 msg.len = sizeof(buffer);
76 msg.buf = buffer;
77
78 err = i2c_transfer(client->adapter, &msg, 1);
79 if (err < 0)
80 return err;
81
82 return 0;
83}
84
85static int pcf8523_voltage_low(struct i2c_client *client)
86{
87 u8 value;
88 int err;
89
90 err = pcf8523_read(client, REG_CONTROL3, &value);
91 if (err < 0)
92 return err;
93
94 return !!(value & REG_CONTROL3_BLF);
95}
96
97static int pcf8523_load_capacitance(struct i2c_client *client)
98{
99 u32 load;
100 u8 value;
101 int err;
102
103 err = pcf8523_read(client, REG_CONTROL1, &value);
104 if (err < 0)
105 return err;
106
107 load = 12500;
108 of_property_read_u32(client->dev.of_node, "quartz-load-femtofarads",
109 &load);
110
111 switch (load) {
112 default:
113 dev_warn(&client->dev, "Unknown quartz-load-femtofarads value: %d. Assuming 12500",
114 load);
115 /* fall through */
116 case 12500:
117 value |= REG_CONTROL1_CAP_SEL;
118 break;
119 case 7000:
120 value &= ~REG_CONTROL1_CAP_SEL;
121 break;
122 }
123
124 err = pcf8523_write(client, REG_CONTROL1, value);
125
126 return err;
127}
128
129static int pcf8523_set_pm(struct i2c_client *client, u8 pm)
130{
131 u8 value;
132 int err;
133
134 err = pcf8523_read(client, REG_CONTROL3, &value);
135 if (err < 0)
136 return err;
137
138 value = (value & ~REG_CONTROL3_PM_MASK) | pm;
139
140 err = pcf8523_write(client, REG_CONTROL3, value);
141 if (err < 0)
142 return err;
143
144 return 0;
145}
146
147static int pcf8523_stop_rtc(struct i2c_client *client)
148{
149 u8 value;
150 int err;
151
152 err = pcf8523_read(client, REG_CONTROL1, &value);
153 if (err < 0)
154 return err;
155
156 value |= REG_CONTROL1_STOP;
157
158 err = pcf8523_write(client, REG_CONTROL1, value);
159 if (err < 0)
160 return err;
161
162 return 0;
163}
164
165static int pcf8523_start_rtc(struct i2c_client *client)
166{
167 u8 value;
168 int err;
169
170 err = pcf8523_read(client, REG_CONTROL1, &value);
171 if (err < 0)
172 return err;
173
174 value &= ~REG_CONTROL1_STOP;
175
176 err = pcf8523_write(client, REG_CONTROL1, value);
177 if (err < 0)
178 return err;
179
180 return 0;
181}
182
183static int pcf8523_rtc_read_time(struct device *dev, struct rtc_time *tm)
184{
185 struct i2c_client *client = to_i2c_client(dev);
186 u8 start = REG_SECONDS, regs[7];
187 struct i2c_msg msgs[2];
188 int err;
189
190 err = pcf8523_voltage_low(client);
191 if (err < 0) {
192 return err;
193 } else if (err > 0) {
194 dev_err(dev, "low voltage detected, time is unreliable\n");
195 return -EINVAL;
196 }
197
198 msgs[0].addr = client->addr;
199 msgs[0].flags = 0;
200 msgs[0].len = 1;
201 msgs[0].buf = &start;
202
203 msgs[1].addr = client->addr;
204 msgs[1].flags = I2C_M_RD;
205 msgs[1].len = sizeof(regs);
206 msgs[1].buf = regs;
207
208 err = i2c_transfer(client->adapter, msgs, ARRAY_SIZE(msgs));
209 if (err < 0)
210 return err;
211
212 if (regs[0] & REG_SECONDS_OS)
213 return -EINVAL;
214
215 tm->tm_sec = bcd2bin(regs[0] & 0x7f);
216 tm->tm_min = bcd2bin(regs[1] & 0x7f);
217 tm->tm_hour = bcd2bin(regs[2] & 0x3f);
218 tm->tm_mday = bcd2bin(regs[3] & 0x3f);
219 tm->tm_wday = regs[4] & 0x7;
220 tm->tm_mon = bcd2bin(regs[5] & 0x1f) - 1;
221 tm->tm_year = bcd2bin(regs[6]) + 100;
222
223 return 0;
224}
225
226static int pcf8523_rtc_set_time(struct device *dev, struct rtc_time *tm)
227{
228 struct i2c_client *client = to_i2c_client(dev);
229 struct i2c_msg msg;
230 u8 regs[8];
231 int err;
232
233 /*
234 * The hardware can only store values between 0 and 99 in it's YEAR
235 * register (with 99 overflowing to 0 on increment).
236 * After 2100-02-28 we could start interpreting the year to be in the
237 * interval [2100, 2199], but there is no path to switch in a smooth way
238 * because the chip handles YEAR=0x00 (and the out-of-spec
239 * YEAR=0xa0) as a leap year, but 2100 isn't.
240 */
241 if (tm->tm_year < 100 || tm->tm_year >= 200)
242 return -EINVAL;
243
244 err = pcf8523_stop_rtc(client);
245 if (err < 0)
246 return err;
247
248 regs[0] = REG_SECONDS;
249 /* This will purposely overwrite REG_SECONDS_OS */
250 regs[1] = bin2bcd(tm->tm_sec);
251 regs[2] = bin2bcd(tm->tm_min);
252 regs[3] = bin2bcd(tm->tm_hour);
253 regs[4] = bin2bcd(tm->tm_mday);
254 regs[5] = tm->tm_wday;
255 regs[6] = bin2bcd(tm->tm_mon + 1);
256 regs[7] = bin2bcd(tm->tm_year - 100);
257
258 msg.addr = client->addr;
259 msg.flags = 0;
260 msg.len = sizeof(regs);
261 msg.buf = regs;
262
263 err = i2c_transfer(client->adapter, &msg, 1);
264 if (err < 0) {
265 /*
266 * If the time cannot be set, restart the RTC anyway. Note
267 * that errors are ignored if the RTC cannot be started so
268 * that we have a chance to propagate the original error.
269 */
270 pcf8523_start_rtc(client);
271 return err;
272 }
273
274 return pcf8523_start_rtc(client);
275}
276
277#ifdef CONFIG_RTC_INTF_DEV
278static int pcf8523_rtc_ioctl(struct device *dev, unsigned int cmd,
279 unsigned long arg)
280{
281 struct i2c_client *client = to_i2c_client(dev);
282 int ret;
283
284 switch (cmd) {
285 case RTC_VL_READ:
286 ret = pcf8523_voltage_low(client);
287 if (ret < 0)
288 return ret;
289
290 if (copy_to_user((void __user *)arg, &ret, sizeof(int)))
291 return -EFAULT;
292
293 return 0;
294 default:
295 return -ENOIOCTLCMD;
296 }
297}
298#else
299#define pcf8523_rtc_ioctl NULL
300#endif
301
302static int pcf8523_rtc_read_offset(struct device *dev, long *offset)
303{
304 struct i2c_client *client = to_i2c_client(dev);
305 int err;
306 u8 value;
307 s8 val;
308
309 err = pcf8523_read(client, REG_OFFSET, &value);
310 if (err < 0)
311 return err;
312
313 /* sign extend the 7-bit offset value */
314 val = value << 1;
315 *offset = (value & REG_OFFSET_MODE ? 4069 : 4340) * (val >> 1);
316
317 return 0;
318}
319
320static int pcf8523_rtc_set_offset(struct device *dev, long offset)
321{
322 struct i2c_client *client = to_i2c_client(dev);
323 long reg_m0, reg_m1;
324 u8 value;
325
326 reg_m0 = clamp(DIV_ROUND_CLOSEST(offset, 4340), -64L, 63L);
327 reg_m1 = clamp(DIV_ROUND_CLOSEST(offset, 4069), -64L, 63L);
328
329 if (abs(reg_m0 * 4340 - offset) < abs(reg_m1 * 4069 - offset))
330 value = reg_m0 & 0x7f;
331 else
332 value = (reg_m1 & 0x7f) | REG_OFFSET_MODE;
333
334 return pcf8523_write(client, REG_OFFSET, value);
335}
336
337static const struct rtc_class_ops pcf8523_rtc_ops = {
338 .read_time = pcf8523_rtc_read_time,
339 .set_time = pcf8523_rtc_set_time,
340 .ioctl = pcf8523_rtc_ioctl,
341 .read_offset = pcf8523_rtc_read_offset,
342 .set_offset = pcf8523_rtc_set_offset,
343};
344
345static int pcf8523_probe(struct i2c_client *client,
346 const struct i2c_device_id *id)
347{
348 struct pcf8523 *pcf;
349 int err;
350
351 if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C))
352 return -ENODEV;
353
354 pcf = devm_kzalloc(&client->dev, sizeof(*pcf), GFP_KERNEL);
355 if (!pcf)
356 return -ENOMEM;
357
358 err = pcf8523_load_capacitance(client);
359 if (err < 0)
360 dev_warn(&client->dev, "failed to set xtal load capacitance: %d",
361 err);
362
363 err = pcf8523_set_pm(client, 0);
364 if (err < 0)
365 return err;
366
367 pcf->rtc = devm_rtc_device_register(&client->dev, DRIVER_NAME,
368 &pcf8523_rtc_ops, THIS_MODULE);
369 if (IS_ERR(pcf->rtc))
370 return PTR_ERR(pcf->rtc);
371
372 i2c_set_clientdata(client, pcf);
373
374 return 0;
375}
376
377static const struct i2c_device_id pcf8523_id[] = {
378 { "pcf8523", 0 },
379 { }
380};
381MODULE_DEVICE_TABLE(i2c, pcf8523_id);
382
383#ifdef CONFIG_OF
384static const struct of_device_id pcf8523_of_match[] = {
385 { .compatible = "nxp,pcf8523" },
386 { .compatible = "microcrystal,rv8523" },
387 { }
388};
389MODULE_DEVICE_TABLE(of, pcf8523_of_match);
390#endif
391
392static struct i2c_driver pcf8523_driver = {
393 .driver = {
394 .name = DRIVER_NAME,
395 .of_match_table = of_match_ptr(pcf8523_of_match),
396 },
397 .probe = pcf8523_probe,
398 .id_table = pcf8523_id,
399};
400module_i2c_driver(pcf8523_driver);
401
402MODULE_AUTHOR("Thierry Reding <thierry.reding@avionic-design.de>");
403MODULE_DESCRIPTION("NXP PCF8523 RTC driver");
404MODULE_LICENSE("GPL v2");
1/*
2 * Copyright (C) 2012 Avionic Design GmbH
3 *
4 * This program is free software; you can redistribute it and/or modify
5 * it under the terms of the GNU General Public License version 2 as
6 * published by the Free Software Foundation.
7 */
8
9#include <linux/bcd.h>
10#include <linux/i2c.h>
11#include <linux/module.h>
12#include <linux/rtc.h>
13#include <linux/of.h>
14
15#define DRIVER_NAME "rtc-pcf8523"
16
17#define REG_CONTROL1 0x00
18#define REG_CONTROL1_CAP_SEL (1 << 7)
19#define REG_CONTROL1_STOP (1 << 5)
20
21#define REG_CONTROL3 0x02
22#define REG_CONTROL3_PM_BLD (1 << 7) /* battery low detection disabled */
23#define REG_CONTROL3_PM_VDD (1 << 6) /* switch-over disabled */
24#define REG_CONTROL3_PM_DSM (1 << 5) /* direct switching mode */
25#define REG_CONTROL3_PM_MASK 0xe0
26#define REG_CONTROL3_BLF (1 << 2) /* battery low bit, read-only */
27
28#define REG_SECONDS 0x03
29#define REG_SECONDS_OS (1 << 7)
30
31#define REG_MINUTES 0x04
32#define REG_HOURS 0x05
33#define REG_DAYS 0x06
34#define REG_WEEKDAYS 0x07
35#define REG_MONTHS 0x08
36#define REG_YEARS 0x09
37
38#define REG_OFFSET 0x0e
39#define REG_OFFSET_MODE BIT(7)
40
41struct pcf8523 {
42 struct rtc_device *rtc;
43};
44
45static int pcf8523_read(struct i2c_client *client, u8 reg, u8 *valuep)
46{
47 struct i2c_msg msgs[2];
48 u8 value = 0;
49 int err;
50
51 msgs[0].addr = client->addr;
52 msgs[0].flags = 0;
53 msgs[0].len = sizeof(reg);
54 msgs[0].buf = ®
55
56 msgs[1].addr = client->addr;
57 msgs[1].flags = I2C_M_RD;
58 msgs[1].len = sizeof(value);
59 msgs[1].buf = &value;
60
61 err = i2c_transfer(client->adapter, msgs, ARRAY_SIZE(msgs));
62 if (err < 0)
63 return err;
64
65 *valuep = value;
66
67 return 0;
68}
69
70static int pcf8523_write(struct i2c_client *client, u8 reg, u8 value)
71{
72 u8 buffer[2] = { reg, value };
73 struct i2c_msg msg;
74 int err;
75
76 msg.addr = client->addr;
77 msg.flags = 0;
78 msg.len = sizeof(buffer);
79 msg.buf = buffer;
80
81 err = i2c_transfer(client->adapter, &msg, 1);
82 if (err < 0)
83 return err;
84
85 return 0;
86}
87
88static int pcf8523_select_capacitance(struct i2c_client *client, bool high)
89{
90 u8 value;
91 int err;
92
93 err = pcf8523_read(client, REG_CONTROL1, &value);
94 if (err < 0)
95 return err;
96
97 if (!high)
98 value &= ~REG_CONTROL1_CAP_SEL;
99 else
100 value |= REG_CONTROL1_CAP_SEL;
101
102 err = pcf8523_write(client, REG_CONTROL1, value);
103 if (err < 0)
104 return err;
105
106 return err;
107}
108
109static int pcf8523_set_pm(struct i2c_client *client, u8 pm)
110{
111 u8 value;
112 int err;
113
114 err = pcf8523_read(client, REG_CONTROL3, &value);
115 if (err < 0)
116 return err;
117
118 value = (value & ~REG_CONTROL3_PM_MASK) | pm;
119
120 err = pcf8523_write(client, REG_CONTROL3, value);
121 if (err < 0)
122 return err;
123
124 return 0;
125}
126
127static int pcf8523_stop_rtc(struct i2c_client *client)
128{
129 u8 value;
130 int err;
131
132 err = pcf8523_read(client, REG_CONTROL1, &value);
133 if (err < 0)
134 return err;
135
136 value |= REG_CONTROL1_STOP;
137
138 err = pcf8523_write(client, REG_CONTROL1, value);
139 if (err < 0)
140 return err;
141
142 return 0;
143}
144
145static int pcf8523_start_rtc(struct i2c_client *client)
146{
147 u8 value;
148 int err;
149
150 err = pcf8523_read(client, REG_CONTROL1, &value);
151 if (err < 0)
152 return err;
153
154 value &= ~REG_CONTROL1_STOP;
155
156 err = pcf8523_write(client, REG_CONTROL1, value);
157 if (err < 0)
158 return err;
159
160 return 0;
161}
162
163static int pcf8523_rtc_read_time(struct device *dev, struct rtc_time *tm)
164{
165 struct i2c_client *client = to_i2c_client(dev);
166 u8 start = REG_SECONDS, regs[7];
167 struct i2c_msg msgs[2];
168 int err;
169
170 msgs[0].addr = client->addr;
171 msgs[0].flags = 0;
172 msgs[0].len = 1;
173 msgs[0].buf = &start;
174
175 msgs[1].addr = client->addr;
176 msgs[1].flags = I2C_M_RD;
177 msgs[1].len = sizeof(regs);
178 msgs[1].buf = regs;
179
180 err = i2c_transfer(client->adapter, msgs, ARRAY_SIZE(msgs));
181 if (err < 0)
182 return err;
183
184 if (regs[0] & REG_SECONDS_OS)
185 return -EINVAL;
186
187 tm->tm_sec = bcd2bin(regs[0] & 0x7f);
188 tm->tm_min = bcd2bin(regs[1] & 0x7f);
189 tm->tm_hour = bcd2bin(regs[2] & 0x3f);
190 tm->tm_mday = bcd2bin(regs[3] & 0x3f);
191 tm->tm_wday = regs[4] & 0x7;
192 tm->tm_mon = bcd2bin(regs[5] & 0x1f) - 1;
193 tm->tm_year = bcd2bin(regs[6]) + 100;
194
195 return 0;
196}
197
198static int pcf8523_rtc_set_time(struct device *dev, struct rtc_time *tm)
199{
200 struct i2c_client *client = to_i2c_client(dev);
201 struct i2c_msg msg;
202 u8 regs[8];
203 int err;
204
205 /*
206 * The hardware can only store values between 0 and 99 in it's YEAR
207 * register (with 99 overflowing to 0 on increment).
208 * After 2100-02-28 we could start interpreting the year to be in the
209 * interval [2100, 2199], but there is no path to switch in a smooth way
210 * because the chip handles YEAR=0x00 (and the out-of-spec
211 * YEAR=0xa0) as a leap year, but 2100 isn't.
212 */
213 if (tm->tm_year < 100 || tm->tm_year >= 200)
214 return -EINVAL;
215
216 err = pcf8523_stop_rtc(client);
217 if (err < 0)
218 return err;
219
220 regs[0] = REG_SECONDS;
221 /* This will purposely overwrite REG_SECONDS_OS */
222 regs[1] = bin2bcd(tm->tm_sec);
223 regs[2] = bin2bcd(tm->tm_min);
224 regs[3] = bin2bcd(tm->tm_hour);
225 regs[4] = bin2bcd(tm->tm_mday);
226 regs[5] = tm->tm_wday;
227 regs[6] = bin2bcd(tm->tm_mon + 1);
228 regs[7] = bin2bcd(tm->tm_year - 100);
229
230 msg.addr = client->addr;
231 msg.flags = 0;
232 msg.len = sizeof(regs);
233 msg.buf = regs;
234
235 err = i2c_transfer(client->adapter, &msg, 1);
236 if (err < 0) {
237 /*
238 * If the time cannot be set, restart the RTC anyway. Note
239 * that errors are ignored if the RTC cannot be started so
240 * that we have a chance to propagate the original error.
241 */
242 pcf8523_start_rtc(client);
243 return err;
244 }
245
246 return pcf8523_start_rtc(client);
247}
248
249#ifdef CONFIG_RTC_INTF_DEV
250static int pcf8523_rtc_ioctl(struct device *dev, unsigned int cmd,
251 unsigned long arg)
252{
253 struct i2c_client *client = to_i2c_client(dev);
254 u8 value;
255 int ret = 0, err;
256
257 switch (cmd) {
258 case RTC_VL_READ:
259 err = pcf8523_read(client, REG_CONTROL3, &value);
260 if (err < 0)
261 return err;
262
263 if (value & REG_CONTROL3_BLF)
264 ret = 1;
265
266 if (copy_to_user((void __user *)arg, &ret, sizeof(int)))
267 return -EFAULT;
268
269 return 0;
270 default:
271 return -ENOIOCTLCMD;
272 }
273}
274#else
275#define pcf8523_rtc_ioctl NULL
276#endif
277
278static int pcf8523_rtc_read_offset(struct device *dev, long *offset)
279{
280 struct i2c_client *client = to_i2c_client(dev);
281 int err;
282 u8 value;
283 s8 val;
284
285 err = pcf8523_read(client, REG_OFFSET, &value);
286 if (err < 0)
287 return err;
288
289 /* sign extend the 7-bit offset value */
290 val = value << 1;
291 *offset = (value & REG_OFFSET_MODE ? 4069 : 4340) * (val >> 1);
292
293 return 0;
294}
295
296static int pcf8523_rtc_set_offset(struct device *dev, long offset)
297{
298 struct i2c_client *client = to_i2c_client(dev);
299 long reg_m0, reg_m1;
300 u8 value;
301
302 reg_m0 = clamp(DIV_ROUND_CLOSEST(offset, 4340), -64L, 63L);
303 reg_m1 = clamp(DIV_ROUND_CLOSEST(offset, 4069), -64L, 63L);
304
305 if (abs(reg_m0 * 4340 - offset) < abs(reg_m1 * 4069 - offset))
306 value = reg_m0 & 0x7f;
307 else
308 value = (reg_m1 & 0x7f) | REG_OFFSET_MODE;
309
310 return pcf8523_write(client, REG_OFFSET, value);
311}
312
313static const struct rtc_class_ops pcf8523_rtc_ops = {
314 .read_time = pcf8523_rtc_read_time,
315 .set_time = pcf8523_rtc_set_time,
316 .ioctl = pcf8523_rtc_ioctl,
317 .read_offset = pcf8523_rtc_read_offset,
318 .set_offset = pcf8523_rtc_set_offset,
319};
320
321static int pcf8523_probe(struct i2c_client *client,
322 const struct i2c_device_id *id)
323{
324 struct pcf8523 *pcf;
325 int err;
326
327 if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C))
328 return -ENODEV;
329
330 pcf = devm_kzalloc(&client->dev, sizeof(*pcf), GFP_KERNEL);
331 if (!pcf)
332 return -ENOMEM;
333
334 err = pcf8523_select_capacitance(client, true);
335 if (err < 0)
336 return err;
337
338 err = pcf8523_set_pm(client, 0);
339 if (err < 0)
340 return err;
341
342 pcf->rtc = devm_rtc_device_register(&client->dev, DRIVER_NAME,
343 &pcf8523_rtc_ops, THIS_MODULE);
344 if (IS_ERR(pcf->rtc))
345 return PTR_ERR(pcf->rtc);
346
347 i2c_set_clientdata(client, pcf);
348
349 return 0;
350}
351
352static const struct i2c_device_id pcf8523_id[] = {
353 { "pcf8523", 0 },
354 { }
355};
356MODULE_DEVICE_TABLE(i2c, pcf8523_id);
357
358#ifdef CONFIG_OF
359static const struct of_device_id pcf8523_of_match[] = {
360 { .compatible = "nxp,pcf8523" },
361 { }
362};
363MODULE_DEVICE_TABLE(of, pcf8523_of_match);
364#endif
365
366static struct i2c_driver pcf8523_driver = {
367 .driver = {
368 .name = DRIVER_NAME,
369 .of_match_table = of_match_ptr(pcf8523_of_match),
370 },
371 .probe = pcf8523_probe,
372 .id_table = pcf8523_id,
373};
374module_i2c_driver(pcf8523_driver);
375
376MODULE_AUTHOR("Thierry Reding <thierry.reding@avionic-design.de>");
377MODULE_DESCRIPTION("NXP PCF8523 RTC driver");
378MODULE_LICENSE("GPL v2");