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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>
18#include <linux/module.h>
19#include <linux/err.h>
20#include <linux/of.h>
21#include <linux/of_device.h>
22
23#define DRV_VERSION "0.1"
24
25/* ISL register offsets */
26#define ISL12022_REG_SC 0x00
27#define ISL12022_REG_MN 0x01
28#define ISL12022_REG_HR 0x02
29#define ISL12022_REG_DT 0x03
30#define ISL12022_REG_MO 0x04
31#define ISL12022_REG_YR 0x05
32#define ISL12022_REG_DW 0x06
33
34#define ISL12022_REG_SR 0x07
35#define ISL12022_REG_INT 0x08
36
37/* ISL register bits */
38#define ISL12022_HR_MIL (1 << 7) /* military or 24 hour time */
39
40#define ISL12022_SR_LBAT85 (1 << 2)
41#define ISL12022_SR_LBAT75 (1 << 1)
42
43#define ISL12022_INT_WRTC (1 << 6)
44
45
46static struct i2c_driver isl12022_driver;
47
48struct isl12022 {
49 struct rtc_device *rtc;
50
51 bool write_enabled; /* true if write enable is set */
52};
53
54
55static int isl12022_read_regs(struct i2c_client *client, uint8_t reg,
56 uint8_t *data, size_t n)
57{
58 struct i2c_msg msgs[] = {
59 {
60 .addr = client->addr,
61 .flags = 0,
62 .len = 1,
63 .buf = data
64 }, /* setup read ptr */
65 {
66 .addr = client->addr,
67 .flags = I2C_M_RD,
68 .len = n,
69 .buf = data
70 }
71 };
72
73 int ret;
74
75 data[0] = reg;
76 ret = i2c_transfer(client->adapter, msgs, ARRAY_SIZE(msgs));
77 if (ret != ARRAY_SIZE(msgs)) {
78 dev_err(&client->dev, "%s: read error, ret=%d\n",
79 __func__, ret);
80 return -EIO;
81 }
82
83 return 0;
84}
85
86
87static int isl12022_write_reg(struct i2c_client *client,
88 uint8_t reg, uint8_t val)
89{
90 uint8_t data[2] = { reg, val };
91 int err;
92
93 err = i2c_master_send(client, data, sizeof(data));
94 if (err != sizeof(data)) {
95 dev_err(&client->dev,
96 "%s: err=%d addr=%02x, data=%02x\n",
97 __func__, err, data[0], data[1]);
98 return -EIO;
99 }
100
101 return 0;
102}
103
104
105/*
106 * In the routines that deal directly with the isl12022 hardware, we use
107 * rtc_time -- month 0-11, hour 0-23, yr = calendar year-epoch.
108 */
109static int isl12022_get_datetime(struct i2c_client *client, struct rtc_time *tm)
110{
111 uint8_t buf[ISL12022_REG_INT + 1];
112 int ret;
113
114 ret = isl12022_read_regs(client, ISL12022_REG_SC, buf, sizeof(buf));
115 if (ret)
116 return ret;
117
118 if (buf[ISL12022_REG_SR] & (ISL12022_SR_LBAT85 | ISL12022_SR_LBAT75)) {
119 dev_warn(&client->dev,
120 "voltage dropped below %u%%, "
121 "date and time is not reliable.\n",
122 buf[ISL12022_REG_SR] & ISL12022_SR_LBAT85 ? 85 : 75);
123 }
124
125 dev_dbg(&client->dev,
126 "%s: raw data is sec=%02x, min=%02x, hr=%02x, "
127 "mday=%02x, mon=%02x, year=%02x, wday=%02x, "
128 "sr=%02x, int=%02x",
129 __func__,
130 buf[ISL12022_REG_SC],
131 buf[ISL12022_REG_MN],
132 buf[ISL12022_REG_HR],
133 buf[ISL12022_REG_DT],
134 buf[ISL12022_REG_MO],
135 buf[ISL12022_REG_YR],
136 buf[ISL12022_REG_DW],
137 buf[ISL12022_REG_SR],
138 buf[ISL12022_REG_INT]);
139
140 tm->tm_sec = bcd2bin(buf[ISL12022_REG_SC] & 0x7F);
141 tm->tm_min = bcd2bin(buf[ISL12022_REG_MN] & 0x7F);
142 tm->tm_hour = bcd2bin(buf[ISL12022_REG_HR] & 0x3F);
143 tm->tm_mday = bcd2bin(buf[ISL12022_REG_DT] & 0x3F);
144 tm->tm_wday = buf[ISL12022_REG_DW] & 0x07;
145 tm->tm_mon = bcd2bin(buf[ISL12022_REG_MO] & 0x1F) - 1;
146 tm->tm_year = bcd2bin(buf[ISL12022_REG_YR]) + 100;
147
148 dev_dbg(&client->dev, "%s: secs=%d, mins=%d, hours=%d, "
149 "mday=%d, mon=%d, year=%d, wday=%d\n",
150 __func__,
151 tm->tm_sec, tm->tm_min, tm->tm_hour,
152 tm->tm_mday, tm->tm_mon, tm->tm_year, tm->tm_wday);
153
154 return rtc_valid_tm(tm);
155}
156
157static int isl12022_set_datetime(struct i2c_client *client, struct rtc_time *tm)
158{
159 struct isl12022 *isl12022 = i2c_get_clientdata(client);
160 size_t i;
161 int ret;
162 uint8_t buf[ISL12022_REG_DW + 1];
163
164 dev_dbg(&client->dev, "%s: secs=%d, mins=%d, hours=%d, "
165 "mday=%d, mon=%d, year=%d, wday=%d\n",
166 __func__,
167 tm->tm_sec, tm->tm_min, tm->tm_hour,
168 tm->tm_mday, tm->tm_mon, tm->tm_year, tm->tm_wday);
169
170 if (!isl12022->write_enabled) {
171
172 ret = isl12022_read_regs(client, ISL12022_REG_INT, buf, 1);
173 if (ret)
174 return ret;
175
176 /* Check if WRTC (write rtc enable) is set factory default is
177 * 0 (not set) */
178 if (!(buf[0] & ISL12022_INT_WRTC)) {
179 dev_info(&client->dev,
180 "init write enable and 24 hour format\n");
181
182 /* Set the write enable bit. */
183 ret = isl12022_write_reg(client,
184 ISL12022_REG_INT,
185 buf[0] | ISL12022_INT_WRTC);
186 if (ret)
187 return ret;
188
189 /* Write to any RTC register to start RTC, we use the
190 * HR register, setting the MIL bit to use the 24 hour
191 * format. */
192 ret = isl12022_read_regs(client, ISL12022_REG_HR,
193 buf, 1);
194 if (ret)
195 return ret;
196
197 ret = isl12022_write_reg(client,
198 ISL12022_REG_HR,
199 buf[0] | ISL12022_HR_MIL);
200 if (ret)
201 return ret;
202 }
203
204 isl12022->write_enabled = 1;
205 }
206
207 /* hours, minutes and seconds */
208 buf[ISL12022_REG_SC] = bin2bcd(tm->tm_sec);
209 buf[ISL12022_REG_MN] = bin2bcd(tm->tm_min);
210 buf[ISL12022_REG_HR] = bin2bcd(tm->tm_hour) | ISL12022_HR_MIL;
211
212 buf[ISL12022_REG_DT] = bin2bcd(tm->tm_mday);
213
214 /* month, 1 - 12 */
215 buf[ISL12022_REG_MO] = bin2bcd(tm->tm_mon + 1);
216
217 /* year and century */
218 buf[ISL12022_REG_YR] = bin2bcd(tm->tm_year % 100);
219
220 buf[ISL12022_REG_DW] = tm->tm_wday & 0x07;
221
222 /* write register's data */
223 for (i = 0; i < ARRAY_SIZE(buf); i++) {
224 ret = isl12022_write_reg(client, ISL12022_REG_SC + i,
225 buf[ISL12022_REG_SC + i]);
226 if (ret)
227 return -EIO;
228 }
229
230 return 0;
231}
232
233static int isl12022_rtc_read_time(struct device *dev, struct rtc_time *tm)
234{
235 return isl12022_get_datetime(to_i2c_client(dev), tm);
236}
237
238static int isl12022_rtc_set_time(struct device *dev, struct rtc_time *tm)
239{
240 return isl12022_set_datetime(to_i2c_client(dev), tm);
241}
242
243static const struct rtc_class_ops isl12022_rtc_ops = {
244 .read_time = isl12022_rtc_read_time,
245 .set_time = isl12022_rtc_set_time,
246};
247
248static int isl12022_probe(struct i2c_client *client,
249 const struct i2c_device_id *id)
250{
251 struct isl12022 *isl12022;
252
253 if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C))
254 return -ENODEV;
255
256 isl12022 = devm_kzalloc(&client->dev, sizeof(struct isl12022),
257 GFP_KERNEL);
258 if (!isl12022)
259 return -ENOMEM;
260
261 dev_dbg(&client->dev, "chip found, driver version " DRV_VERSION "\n");
262
263 i2c_set_clientdata(client, isl12022);
264
265 isl12022->rtc = devm_rtc_device_register(&client->dev,
266 isl12022_driver.driver.name,
267 &isl12022_rtc_ops, THIS_MODULE);
268 return PTR_ERR_OR_ZERO(isl12022->rtc);
269}
270
271#ifdef CONFIG_OF
272static const struct of_device_id isl12022_dt_match[] = {
273 { .compatible = "isl,isl12022" }, /* for backward compat., don't use */
274 { .compatible = "isil,isl12022" },
275 { },
276};
277MODULE_DEVICE_TABLE(of, isl12022_dt_match);
278#endif
279
280static const struct i2c_device_id isl12022_id[] = {
281 { "isl12022", 0 },
282 { }
283};
284MODULE_DEVICE_TABLE(i2c, isl12022_id);
285
286static struct i2c_driver isl12022_driver = {
287 .driver = {
288 .name = "rtc-isl12022",
289#ifdef CONFIG_OF
290 .of_match_table = of_match_ptr(isl12022_dt_match),
291#endif
292 },
293 .probe = isl12022_probe,
294 .id_table = isl12022_id,
295};
296
297module_i2c_driver(isl12022_driver);
298
299MODULE_AUTHOR("roman.fietze@telemotive.de");
300MODULE_DESCRIPTION("ISL 12022 RTC driver");
301MODULE_LICENSE("GPL");
302MODULE_VERSION(DRV_VERSION);
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>
18
19#define DRV_VERSION "0.1"
20
21/* ISL register offsets */
22#define ISL12022_REG_SC 0x00
23#define ISL12022_REG_MN 0x01
24#define ISL12022_REG_HR 0x02
25#define ISL12022_REG_DT 0x03
26#define ISL12022_REG_MO 0x04
27#define ISL12022_REG_YR 0x05
28#define ISL12022_REG_DW 0x06
29
30#define ISL12022_REG_SR 0x07
31#define ISL12022_REG_INT 0x08
32
33/* ISL register bits */
34#define ISL12022_HR_MIL (1 << 7) /* military or 24 hour time */
35
36#define ISL12022_SR_LBAT85 (1 << 2)
37#define ISL12022_SR_LBAT75 (1 << 1)
38
39#define ISL12022_INT_WRTC (1 << 6)
40
41
42static struct i2c_driver isl12022_driver;
43
44struct isl12022 {
45 struct rtc_device *rtc;
46
47 bool write_enabled; /* true if write enable is set */
48};
49
50
51static int isl12022_read_regs(struct i2c_client *client, uint8_t reg,
52 uint8_t *data, size_t n)
53{
54 struct i2c_msg msgs[] = {
55 {
56 .addr = client->addr,
57 .flags = 0,
58 .len = 1,
59 .buf = data
60 }, /* setup read ptr */
61 {
62 .addr = client->addr,
63 .flags = I2C_M_RD,
64 .len = n,
65 .buf = data
66 }
67 };
68
69 int ret;
70
71 data[0] = reg;
72 ret = i2c_transfer(client->adapter, msgs, ARRAY_SIZE(msgs));
73 if (ret != ARRAY_SIZE(msgs)) {
74 dev_err(&client->dev, "%s: read error, ret=%d\n",
75 __func__, ret);
76 return -EIO;
77 }
78
79 return 0;
80}
81
82
83static int isl12022_write_reg(struct i2c_client *client,
84 uint8_t reg, uint8_t val)
85{
86 uint8_t data[2] = { reg, val };
87 int err;
88
89 err = i2c_master_send(client, data, sizeof(data));
90 if (err != sizeof(data)) {
91 dev_err(&client->dev,
92 "%s: err=%d addr=%02x, data=%02x\n",
93 __func__, err, data[0], data[1]);
94 return -EIO;
95 }
96
97 return 0;
98}
99
100
101/*
102 * In the routines that deal directly with the isl12022 hardware, we use
103 * rtc_time -- month 0-11, hour 0-23, yr = calendar year-epoch.
104 */
105static int isl12022_get_datetime(struct i2c_client *client, struct rtc_time *tm)
106{
107 uint8_t buf[ISL12022_REG_INT + 1];
108 int ret;
109
110 ret = isl12022_read_regs(client, ISL12022_REG_SC, buf, sizeof(buf));
111 if (ret)
112 return ret;
113
114 if (buf[ISL12022_REG_SR] & (ISL12022_SR_LBAT85 | ISL12022_SR_LBAT75)) {
115 dev_warn(&client->dev,
116 "voltage dropped below %u%%, "
117 "date and time is not reliable.\n",
118 buf[ISL12022_REG_SR] & ISL12022_SR_LBAT85 ? 85 : 75);
119 }
120
121 dev_dbg(&client->dev,
122 "%s: raw data is sec=%02x, min=%02x, hr=%02x, "
123 "mday=%02x, mon=%02x, year=%02x, wday=%02x, "
124 "sr=%02x, int=%02x",
125 __func__,
126 buf[ISL12022_REG_SC],
127 buf[ISL12022_REG_MN],
128 buf[ISL12022_REG_HR],
129 buf[ISL12022_REG_DT],
130 buf[ISL12022_REG_MO],
131 buf[ISL12022_REG_YR],
132 buf[ISL12022_REG_DW],
133 buf[ISL12022_REG_SR],
134 buf[ISL12022_REG_INT]);
135
136 tm->tm_sec = bcd2bin(buf[ISL12022_REG_SC] & 0x7F);
137 tm->tm_min = bcd2bin(buf[ISL12022_REG_MN] & 0x7F);
138 tm->tm_hour = bcd2bin(buf[ISL12022_REG_HR] & 0x3F);
139 tm->tm_mday = bcd2bin(buf[ISL12022_REG_DT] & 0x3F);
140 tm->tm_wday = buf[ISL12022_REG_DW] & 0x07;
141 tm->tm_mon = bcd2bin(buf[ISL12022_REG_MO] & 0x1F) - 1;
142 tm->tm_year = bcd2bin(buf[ISL12022_REG_YR]) + 100;
143
144 dev_dbg(&client->dev, "%s: secs=%d, mins=%d, hours=%d, "
145 "mday=%d, mon=%d, year=%d, wday=%d\n",
146 __func__,
147 tm->tm_sec, tm->tm_min, tm->tm_hour,
148 tm->tm_mday, tm->tm_mon, tm->tm_year, tm->tm_wday);
149
150 /* The clock can give out invalid datetime, but we cannot return
151 * -EINVAL otherwise hwclock will refuse to set the time on bootup. */
152 if (rtc_valid_tm(tm) < 0)
153 dev_err(&client->dev, "retrieved date and time is invalid.\n");
154
155 return 0;
156}
157
158static int isl12022_set_datetime(struct i2c_client *client, struct rtc_time *tm)
159{
160 struct isl12022 *isl12022 = i2c_get_clientdata(client);
161 size_t i;
162 int ret;
163 uint8_t buf[ISL12022_REG_DW + 1];
164
165 dev_dbg(&client->dev, "%s: secs=%d, mins=%d, hours=%d, "
166 "mday=%d, mon=%d, year=%d, wday=%d\n",
167 __func__,
168 tm->tm_sec, tm->tm_min, tm->tm_hour,
169 tm->tm_mday, tm->tm_mon, tm->tm_year, tm->tm_wday);
170
171 if (!isl12022->write_enabled) {
172
173 ret = isl12022_read_regs(client, ISL12022_REG_INT, buf, 1);
174 if (ret)
175 return ret;
176
177 /* Check if WRTC (write rtc enable) is set factory default is
178 * 0 (not set) */
179 if (!(buf[0] & ISL12022_INT_WRTC)) {
180 dev_info(&client->dev,
181 "init write enable and 24 hour format\n");
182
183 /* Set the write enable bit. */
184 ret = isl12022_write_reg(client,
185 ISL12022_REG_INT,
186 buf[0] | ISL12022_INT_WRTC);
187 if (ret)
188 return ret;
189
190 /* Write to any RTC register to start RTC, we use the
191 * HR register, setting the MIL bit to use the 24 hour
192 * format. */
193 ret = isl12022_read_regs(client, ISL12022_REG_HR,
194 buf, 1);
195 if (ret)
196 return ret;
197
198 ret = isl12022_write_reg(client,
199 ISL12022_REG_HR,
200 buf[0] | ISL12022_HR_MIL);
201 if (ret)
202 return ret;
203 }
204
205 isl12022->write_enabled = 1;
206 }
207
208 /* hours, minutes and seconds */
209 buf[ISL12022_REG_SC] = bin2bcd(tm->tm_sec);
210 buf[ISL12022_REG_MN] = bin2bcd(tm->tm_min);
211 buf[ISL12022_REG_HR] = bin2bcd(tm->tm_hour) | ISL12022_HR_MIL;
212
213 buf[ISL12022_REG_DT] = bin2bcd(tm->tm_mday);
214
215 /* month, 1 - 12 */
216 buf[ISL12022_REG_MO] = bin2bcd(tm->tm_mon + 1);
217
218 /* year and century */
219 buf[ISL12022_REG_YR] = bin2bcd(tm->tm_year % 100);
220
221 buf[ISL12022_REG_DW] = tm->tm_wday & 0x07;
222
223 /* write register's data */
224 for (i = 0; i < ARRAY_SIZE(buf); i++) {
225 ret = isl12022_write_reg(client, ISL12022_REG_SC + i,
226 buf[ISL12022_REG_SC + i]);
227 if (ret)
228 return -EIO;
229 };
230
231 return 0;
232}
233
234static int isl12022_rtc_read_time(struct device *dev, struct rtc_time *tm)
235{
236 return isl12022_get_datetime(to_i2c_client(dev), tm);
237}
238
239static int isl12022_rtc_set_time(struct device *dev, struct rtc_time *tm)
240{
241 return isl12022_set_datetime(to_i2c_client(dev), tm);
242}
243
244static const struct rtc_class_ops isl12022_rtc_ops = {
245 .read_time = isl12022_rtc_read_time,
246 .set_time = isl12022_rtc_set_time,
247};
248
249static int isl12022_probe(struct i2c_client *client,
250 const struct i2c_device_id *id)
251{
252 struct isl12022 *isl12022;
253
254 int ret = 0;
255
256 if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C))
257 return -ENODEV;
258
259 isl12022 = kzalloc(sizeof(struct isl12022), GFP_KERNEL);
260 if (!isl12022)
261 return -ENOMEM;
262
263 dev_dbg(&client->dev, "chip found, driver version " DRV_VERSION "\n");
264
265 i2c_set_clientdata(client, isl12022);
266
267 isl12022->rtc = rtc_device_register(isl12022_driver.driver.name,
268 &client->dev,
269 &isl12022_rtc_ops,
270 THIS_MODULE);
271
272 if (IS_ERR(isl12022->rtc)) {
273 ret = PTR_ERR(isl12022->rtc);
274 goto exit_kfree;
275 }
276
277 return 0;
278
279exit_kfree:
280 kfree(isl12022);
281
282 return ret;
283}
284
285static int isl12022_remove(struct i2c_client *client)
286{
287 struct isl12022 *isl12022 = i2c_get_clientdata(client);
288
289 rtc_device_unregister(isl12022->rtc);
290 kfree(isl12022);
291
292 return 0;
293}
294
295static const struct i2c_device_id isl12022_id[] = {
296 { "isl12022", 0 },
297 { "rtc8564", 0 },
298 { }
299};
300MODULE_DEVICE_TABLE(i2c, isl12022_id);
301
302static struct i2c_driver isl12022_driver = {
303 .driver = {
304 .name = "rtc-isl12022",
305 },
306 .probe = isl12022_probe,
307 .remove = isl12022_remove,
308 .id_table = isl12022_id,
309};
310
311static int __init isl12022_init(void)
312{
313 return i2c_add_driver(&isl12022_driver);
314}
315
316static void __exit isl12022_exit(void)
317{
318 i2c_del_driver(&isl12022_driver);
319}
320
321module_init(isl12022_init);
322module_exit(isl12022_exit);
323
324MODULE_AUTHOR("roman.fietze@telemotive.de");
325MODULE_DESCRIPTION("ISL 12022 RTC driver");
326MODULE_LICENSE("GPL");
327MODULE_VERSION(DRV_VERSION);