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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#include <linux/module.h>
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
43static struct i2c_driver isl12022_driver;
44
45struct isl12022 {
46 struct rtc_device *rtc;
47
48 bool write_enabled; /* true if write enable is set */
49};
50
51
52static 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
84static 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 */
106static 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
159static 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);
212 buf[ISL12022_REG_HR] = bin2bcd(tm->tm_hour) | ISL12022_HR_MIL;
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
235static 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
240static 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
245static const struct rtc_class_ops isl12022_rtc_ops = {
246 .read_time = isl12022_rtc_read_time,
247 .set_time = isl12022_rtc_set_time,
248};
249
250static 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
280exit_kfree:
281 kfree(isl12022);
282
283 return ret;
284}
285
286static 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
296static const struct i2c_device_id isl12022_id[] = {
297 { "isl12022", 0 },
298 { "rtc8564", 0 },
299 { }
300};
301MODULE_DEVICE_TABLE(i2c, isl12022_id);
302
303static 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
312module_i2c_driver(isl12022_driver);
313
314MODULE_AUTHOR("roman.fietze@telemotive.de");
315MODULE_DESCRIPTION("ISL 12022 RTC driver");
316MODULE_LICENSE("GPL");
317MODULE_VERSION(DRV_VERSION);