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1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * An I2C driver for the Intersil ISL 12022
4 *
5 * Author: Roman Fietze <roman.fietze@telemotive.de>
6 *
7 * Based on the Philips PCF8563 RTC
8 * by Alessandro Zummo <a.zummo@towertech.it>.
9 */
10
11#include <linux/i2c.h>
12#include <linux/bcd.h>
13#include <linux/rtc.h>
14#include <linux/slab.h>
15#include <linux/module.h>
16#include <linux/err.h>
17#include <linux/of.h>
18#include <linux/of_device.h>
19
20/* ISL register offsets */
21#define ISL12022_REG_SC 0x00
22#define ISL12022_REG_MN 0x01
23#define ISL12022_REG_HR 0x02
24#define ISL12022_REG_DT 0x03
25#define ISL12022_REG_MO 0x04
26#define ISL12022_REG_YR 0x05
27#define ISL12022_REG_DW 0x06
28
29#define ISL12022_REG_SR 0x07
30#define ISL12022_REG_INT 0x08
31
32/* ISL register bits */
33#define ISL12022_HR_MIL (1 << 7) /* military or 24 hour time */
34
35#define ISL12022_SR_LBAT85 (1 << 2)
36#define ISL12022_SR_LBAT75 (1 << 1)
37
38#define ISL12022_INT_WRTC (1 << 6)
39
40
41static struct i2c_driver isl12022_driver;
42
43struct isl12022 {
44 struct rtc_device *rtc;
45
46 bool write_enabled; /* true if write enable is set */
47};
48
49
50static int isl12022_read_regs(struct i2c_client *client, uint8_t reg,
51 uint8_t *data, size_t n)
52{
53 struct i2c_msg msgs[] = {
54 {
55 .addr = client->addr,
56 .flags = 0,
57 .len = 1,
58 .buf = data
59 }, /* setup read ptr */
60 {
61 .addr = client->addr,
62 .flags = I2C_M_RD,
63 .len = n,
64 .buf = data
65 }
66 };
67
68 int ret;
69
70 data[0] = reg;
71 ret = i2c_transfer(client->adapter, msgs, ARRAY_SIZE(msgs));
72 if (ret != ARRAY_SIZE(msgs)) {
73 dev_err(&client->dev, "%s: read error, ret=%d\n",
74 __func__, ret);
75 return -EIO;
76 }
77
78 return 0;
79}
80
81
82static int isl12022_write_reg(struct i2c_client *client,
83 uint8_t reg, uint8_t val)
84{
85 uint8_t data[2] = { reg, val };
86 int err;
87
88 err = i2c_master_send(client, data, sizeof(data));
89 if (err != sizeof(data)) {
90 dev_err(&client->dev,
91 "%s: err=%d addr=%02x, data=%02x\n",
92 __func__, err, data[0], data[1]);
93 return -EIO;
94 }
95
96 return 0;
97}
98
99
100/*
101 * In the routines that deal directly with the isl12022 hardware, we use
102 * rtc_time -- month 0-11, hour 0-23, yr = calendar year-epoch.
103 */
104static int isl12022_rtc_read_time(struct device *dev, struct rtc_time *tm)
105{
106 struct i2c_client *client = to_i2c_client(dev);
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 return 0;
151}
152
153static int isl12022_rtc_set_time(struct device *dev, struct rtc_time *tm)
154{
155 struct i2c_client *client = to_i2c_client(dev);
156 struct isl12022 *isl12022 = i2c_get_clientdata(client);
157 size_t i;
158 int ret;
159 uint8_t buf[ISL12022_REG_DW + 1];
160
161 dev_dbg(&client->dev, "%s: secs=%d, mins=%d, hours=%d, "
162 "mday=%d, mon=%d, year=%d, wday=%d\n",
163 __func__,
164 tm->tm_sec, tm->tm_min, tm->tm_hour,
165 tm->tm_mday, tm->tm_mon, tm->tm_year, tm->tm_wday);
166
167 if (!isl12022->write_enabled) {
168
169 ret = isl12022_read_regs(client, ISL12022_REG_INT, buf, 1);
170 if (ret)
171 return ret;
172
173 /* Check if WRTC (write rtc enable) is set factory default is
174 * 0 (not set) */
175 if (!(buf[0] & ISL12022_INT_WRTC)) {
176 dev_info(&client->dev,
177 "init write enable and 24 hour format\n");
178
179 /* Set the write enable bit. */
180 ret = isl12022_write_reg(client,
181 ISL12022_REG_INT,
182 buf[0] | ISL12022_INT_WRTC);
183 if (ret)
184 return ret;
185
186 /* Write to any RTC register to start RTC, we use the
187 * HR register, setting the MIL bit to use the 24 hour
188 * format. */
189 ret = isl12022_read_regs(client, ISL12022_REG_HR,
190 buf, 1);
191 if (ret)
192 return ret;
193
194 ret = isl12022_write_reg(client,
195 ISL12022_REG_HR,
196 buf[0] | ISL12022_HR_MIL);
197 if (ret)
198 return ret;
199 }
200
201 isl12022->write_enabled = true;
202 }
203
204 /* hours, minutes and seconds */
205 buf[ISL12022_REG_SC] = bin2bcd(tm->tm_sec);
206 buf[ISL12022_REG_MN] = bin2bcd(tm->tm_min);
207 buf[ISL12022_REG_HR] = bin2bcd(tm->tm_hour) | ISL12022_HR_MIL;
208
209 buf[ISL12022_REG_DT] = bin2bcd(tm->tm_mday);
210
211 /* month, 1 - 12 */
212 buf[ISL12022_REG_MO] = bin2bcd(tm->tm_mon + 1);
213
214 /* year and century */
215 buf[ISL12022_REG_YR] = bin2bcd(tm->tm_year % 100);
216
217 buf[ISL12022_REG_DW] = tm->tm_wday & 0x07;
218
219 /* write register's data */
220 for (i = 0; i < ARRAY_SIZE(buf); i++) {
221 ret = isl12022_write_reg(client, ISL12022_REG_SC + i,
222 buf[ISL12022_REG_SC + i]);
223 if (ret)
224 return -EIO;
225 }
226
227 return 0;
228}
229
230static const struct rtc_class_ops isl12022_rtc_ops = {
231 .read_time = isl12022_rtc_read_time,
232 .set_time = isl12022_rtc_set_time,
233};
234
235static int isl12022_probe(struct i2c_client *client,
236 const struct i2c_device_id *id)
237{
238 struct isl12022 *isl12022;
239
240 if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C))
241 return -ENODEV;
242
243 isl12022 = devm_kzalloc(&client->dev, sizeof(struct isl12022),
244 GFP_KERNEL);
245 if (!isl12022)
246 return -ENOMEM;
247
248 i2c_set_clientdata(client, isl12022);
249
250 isl12022->rtc = devm_rtc_device_register(&client->dev,
251 isl12022_driver.driver.name,
252 &isl12022_rtc_ops, THIS_MODULE);
253 return PTR_ERR_OR_ZERO(isl12022->rtc);
254}
255
256#ifdef CONFIG_OF
257static const struct of_device_id isl12022_dt_match[] = {
258 { .compatible = "isl,isl12022" }, /* for backward compat., don't use */
259 { .compatible = "isil,isl12022" },
260 { },
261};
262MODULE_DEVICE_TABLE(of, isl12022_dt_match);
263#endif
264
265static const struct i2c_device_id isl12022_id[] = {
266 { "isl12022", 0 },
267 { }
268};
269MODULE_DEVICE_TABLE(i2c, isl12022_id);
270
271static struct i2c_driver isl12022_driver = {
272 .driver = {
273 .name = "rtc-isl12022",
274#ifdef CONFIG_OF
275 .of_match_table = of_match_ptr(isl12022_dt_match),
276#endif
277 },
278 .probe = isl12022_probe,
279 .id_table = isl12022_id,
280};
281
282module_i2c_driver(isl12022_driver);
283
284MODULE_AUTHOR("roman.fietze@telemotive.de");
285MODULE_DESCRIPTION("ISL 12022 RTC driver");
286MODULE_LICENSE("GPL");
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/* ISL register offsets */
24#define ISL12022_REG_SC 0x00
25#define ISL12022_REG_MN 0x01
26#define ISL12022_REG_HR 0x02
27#define ISL12022_REG_DT 0x03
28#define ISL12022_REG_MO 0x04
29#define ISL12022_REG_YR 0x05
30#define ISL12022_REG_DW 0x06
31
32#define ISL12022_REG_SR 0x07
33#define ISL12022_REG_INT 0x08
34
35/* ISL register bits */
36#define ISL12022_HR_MIL (1 << 7) /* military or 24 hour time */
37
38#define ISL12022_SR_LBAT85 (1 << 2)
39#define ISL12022_SR_LBAT75 (1 << 1)
40
41#define ISL12022_INT_WRTC (1 << 6)
42
43
44static struct i2c_driver isl12022_driver;
45
46struct isl12022 {
47 struct rtc_device *rtc;
48
49 bool write_enabled; /* true if write enable is set */
50};
51
52
53static int isl12022_read_regs(struct i2c_client *client, uint8_t reg,
54 uint8_t *data, size_t n)
55{
56 struct i2c_msg msgs[] = {
57 {
58 .addr = client->addr,
59 .flags = 0,
60 .len = 1,
61 .buf = data
62 }, /* setup read ptr */
63 {
64 .addr = client->addr,
65 .flags = I2C_M_RD,
66 .len = n,
67 .buf = data
68 }
69 };
70
71 int ret;
72
73 data[0] = reg;
74 ret = i2c_transfer(client->adapter, msgs, ARRAY_SIZE(msgs));
75 if (ret != ARRAY_SIZE(msgs)) {
76 dev_err(&client->dev, "%s: read error, ret=%d\n",
77 __func__, ret);
78 return -EIO;
79 }
80
81 return 0;
82}
83
84
85static int isl12022_write_reg(struct i2c_client *client,
86 uint8_t reg, uint8_t val)
87{
88 uint8_t data[2] = { reg, val };
89 int err;
90
91 err = i2c_master_send(client, data, sizeof(data));
92 if (err != sizeof(data)) {
93 dev_err(&client->dev,
94 "%s: err=%d addr=%02x, data=%02x\n",
95 __func__, err, data[0], data[1]);
96 return -EIO;
97 }
98
99 return 0;
100}
101
102
103/*
104 * In the routines that deal directly with the isl12022 hardware, we use
105 * rtc_time -- month 0-11, hour 0-23, yr = calendar year-epoch.
106 */
107static int isl12022_get_datetime(struct i2c_client *client, struct rtc_time *tm)
108{
109 uint8_t buf[ISL12022_REG_INT + 1];
110 int ret;
111
112 ret = isl12022_read_regs(client, ISL12022_REG_SC, buf, sizeof(buf));
113 if (ret)
114 return ret;
115
116 if (buf[ISL12022_REG_SR] & (ISL12022_SR_LBAT85 | ISL12022_SR_LBAT75)) {
117 dev_warn(&client->dev,
118 "voltage dropped below %u%%, "
119 "date and time is not reliable.\n",
120 buf[ISL12022_REG_SR] & ISL12022_SR_LBAT85 ? 85 : 75);
121 }
122
123 dev_dbg(&client->dev,
124 "%s: raw data is sec=%02x, min=%02x, hr=%02x, "
125 "mday=%02x, mon=%02x, year=%02x, wday=%02x, "
126 "sr=%02x, int=%02x",
127 __func__,
128 buf[ISL12022_REG_SC],
129 buf[ISL12022_REG_MN],
130 buf[ISL12022_REG_HR],
131 buf[ISL12022_REG_DT],
132 buf[ISL12022_REG_MO],
133 buf[ISL12022_REG_YR],
134 buf[ISL12022_REG_DW],
135 buf[ISL12022_REG_SR],
136 buf[ISL12022_REG_INT]);
137
138 tm->tm_sec = bcd2bin(buf[ISL12022_REG_SC] & 0x7F);
139 tm->tm_min = bcd2bin(buf[ISL12022_REG_MN] & 0x7F);
140 tm->tm_hour = bcd2bin(buf[ISL12022_REG_HR] & 0x3F);
141 tm->tm_mday = bcd2bin(buf[ISL12022_REG_DT] & 0x3F);
142 tm->tm_wday = buf[ISL12022_REG_DW] & 0x07;
143 tm->tm_mon = bcd2bin(buf[ISL12022_REG_MO] & 0x1F) - 1;
144 tm->tm_year = bcd2bin(buf[ISL12022_REG_YR]) + 100;
145
146 dev_dbg(&client->dev, "%s: secs=%d, mins=%d, hours=%d, "
147 "mday=%d, mon=%d, year=%d, wday=%d\n",
148 __func__,
149 tm->tm_sec, tm->tm_min, tm->tm_hour,
150 tm->tm_mday, tm->tm_mon, tm->tm_year, tm->tm_wday);
151
152 return rtc_valid_tm(tm);
153}
154
155static int isl12022_set_datetime(struct i2c_client *client, struct rtc_time *tm)
156{
157 struct isl12022 *isl12022 = i2c_get_clientdata(client);
158 size_t i;
159 int ret;
160 uint8_t buf[ISL12022_REG_DW + 1];
161
162 dev_dbg(&client->dev, "%s: secs=%d, mins=%d, hours=%d, "
163 "mday=%d, mon=%d, year=%d, wday=%d\n",
164 __func__,
165 tm->tm_sec, tm->tm_min, tm->tm_hour,
166 tm->tm_mday, tm->tm_mon, tm->tm_year, tm->tm_wday);
167
168 if (!isl12022->write_enabled) {
169
170 ret = isl12022_read_regs(client, ISL12022_REG_INT, buf, 1);
171 if (ret)
172 return ret;
173
174 /* Check if WRTC (write rtc enable) is set factory default is
175 * 0 (not set) */
176 if (!(buf[0] & ISL12022_INT_WRTC)) {
177 dev_info(&client->dev,
178 "init write enable and 24 hour format\n");
179
180 /* Set the write enable bit. */
181 ret = isl12022_write_reg(client,
182 ISL12022_REG_INT,
183 buf[0] | ISL12022_INT_WRTC);
184 if (ret)
185 return ret;
186
187 /* Write to any RTC register to start RTC, we use the
188 * HR register, setting the MIL bit to use the 24 hour
189 * format. */
190 ret = isl12022_read_regs(client, ISL12022_REG_HR,
191 buf, 1);
192 if (ret)
193 return ret;
194
195 ret = isl12022_write_reg(client,
196 ISL12022_REG_HR,
197 buf[0] | ISL12022_HR_MIL);
198 if (ret)
199 return ret;
200 }
201
202 isl12022->write_enabled = 1;
203 }
204
205 /* hours, minutes and seconds */
206 buf[ISL12022_REG_SC] = bin2bcd(tm->tm_sec);
207 buf[ISL12022_REG_MN] = bin2bcd(tm->tm_min);
208 buf[ISL12022_REG_HR] = bin2bcd(tm->tm_hour) | ISL12022_HR_MIL;
209
210 buf[ISL12022_REG_DT] = bin2bcd(tm->tm_mday);
211
212 /* month, 1 - 12 */
213 buf[ISL12022_REG_MO] = bin2bcd(tm->tm_mon + 1);
214
215 /* year and century */
216 buf[ISL12022_REG_YR] = bin2bcd(tm->tm_year % 100);
217
218 buf[ISL12022_REG_DW] = tm->tm_wday & 0x07;
219
220 /* write register's data */
221 for (i = 0; i < ARRAY_SIZE(buf); i++) {
222 ret = isl12022_write_reg(client, ISL12022_REG_SC + i,
223 buf[ISL12022_REG_SC + i]);
224 if (ret)
225 return -EIO;
226 }
227
228 return 0;
229}
230
231static int isl12022_rtc_read_time(struct device *dev, struct rtc_time *tm)
232{
233 return isl12022_get_datetime(to_i2c_client(dev), tm);
234}
235
236static int isl12022_rtc_set_time(struct device *dev, struct rtc_time *tm)
237{
238 return isl12022_set_datetime(to_i2c_client(dev), tm);
239}
240
241static const struct rtc_class_ops isl12022_rtc_ops = {
242 .read_time = isl12022_rtc_read_time,
243 .set_time = isl12022_rtc_set_time,
244};
245
246static int isl12022_probe(struct i2c_client *client,
247 const struct i2c_device_id *id)
248{
249 struct isl12022 *isl12022;
250
251 if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C))
252 return -ENODEV;
253
254 isl12022 = devm_kzalloc(&client->dev, sizeof(struct isl12022),
255 GFP_KERNEL);
256 if (!isl12022)
257 return -ENOMEM;
258
259 i2c_set_clientdata(client, isl12022);
260
261 isl12022->rtc = devm_rtc_device_register(&client->dev,
262 isl12022_driver.driver.name,
263 &isl12022_rtc_ops, THIS_MODULE);
264 return PTR_ERR_OR_ZERO(isl12022->rtc);
265}
266
267#ifdef CONFIG_OF
268static const struct of_device_id isl12022_dt_match[] = {
269 { .compatible = "isl,isl12022" }, /* for backward compat., don't use */
270 { .compatible = "isil,isl12022" },
271 { },
272};
273MODULE_DEVICE_TABLE(of, isl12022_dt_match);
274#endif
275
276static const struct i2c_device_id isl12022_id[] = {
277 { "isl12022", 0 },
278 { }
279};
280MODULE_DEVICE_TABLE(i2c, isl12022_id);
281
282static struct i2c_driver isl12022_driver = {
283 .driver = {
284 .name = "rtc-isl12022",
285#ifdef CONFIG_OF
286 .of_match_table = of_match_ptr(isl12022_dt_match),
287#endif
288 },
289 .probe = isl12022_probe,
290 .id_table = isl12022_id,
291};
292
293module_i2c_driver(isl12022_driver);
294
295MODULE_AUTHOR("roman.fietze@telemotive.de");
296MODULE_DESCRIPTION("ISL 12022 RTC driver");
297MODULE_LICENSE("GPL");