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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#include <linux/regmap.h>
20#include <linux/hwmon.h>
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#define ISL12022_REG_BETA 0x0d
35#define ISL12022_REG_TEMP_L 0x28
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#define ISL12022_BETA_TSE (1 << 7)
46
47static struct i2c_driver isl12022_driver;
48
49struct isl12022 {
50 struct rtc_device *rtc;
51 struct regmap *regmap;
52};
53
54static umode_t isl12022_hwmon_is_visible(const void *data,
55 enum hwmon_sensor_types type,
56 u32 attr, int channel)
57{
58 if (type == hwmon_temp && attr == hwmon_temp_input)
59 return 0444;
60
61 return 0;
62}
63
64/*
65 * A user-initiated temperature conversion is not started by this function,
66 * so the temperature is updated once every ~60 seconds.
67 */
68static int isl12022_hwmon_read_temp(struct device *dev, long *mC)
69{
70 struct isl12022 *isl12022 = dev_get_drvdata(dev);
71 struct regmap *regmap = isl12022->regmap;
72 u8 temp_buf[2];
73 int temp, ret;
74
75 ret = regmap_bulk_read(regmap, ISL12022_REG_TEMP_L,
76 temp_buf, sizeof(temp_buf));
77 if (ret)
78 return ret;
79 /*
80 * Temperature is represented as a 10-bit number, unit half-Kelvins.
81 */
82 temp = (temp_buf[1] << 8) | temp_buf[0];
83 temp *= 500;
84 temp -= 273000;
85
86 *mC = temp;
87
88 return 0;
89}
90
91static int isl12022_hwmon_read(struct device *dev,
92 enum hwmon_sensor_types type,
93 u32 attr, int channel, long *val)
94{
95 if (type == hwmon_temp && attr == hwmon_temp_input)
96 return isl12022_hwmon_read_temp(dev, val);
97
98 return -EOPNOTSUPP;
99}
100
101static const struct hwmon_channel_info *isl12022_hwmon_info[] = {
102 HWMON_CHANNEL_INFO(temp, HWMON_T_INPUT),
103 NULL
104};
105
106static const struct hwmon_ops isl12022_hwmon_ops = {
107 .is_visible = isl12022_hwmon_is_visible,
108 .read = isl12022_hwmon_read,
109};
110
111static const struct hwmon_chip_info isl12022_hwmon_chip_info = {
112 .ops = &isl12022_hwmon_ops,
113 .info = isl12022_hwmon_info,
114};
115
116static void isl12022_hwmon_register(struct device *dev)
117{
118 struct isl12022 *isl12022;
119 struct device *hwmon;
120 int ret;
121
122 if (!IS_REACHABLE(CONFIG_HWMON))
123 return;
124
125 isl12022 = dev_get_drvdata(dev);
126
127 ret = regmap_update_bits(isl12022->regmap, ISL12022_REG_BETA,
128 ISL12022_BETA_TSE, ISL12022_BETA_TSE);
129 if (ret) {
130 dev_warn(dev, "unable to enable temperature sensor\n");
131 return;
132 }
133
134 hwmon = devm_hwmon_device_register_with_info(dev, "isl12022", isl12022,
135 &isl12022_hwmon_chip_info,
136 NULL);
137 if (IS_ERR(hwmon))
138 dev_warn(dev, "unable to register hwmon device: %pe\n", hwmon);
139}
140
141/*
142 * In the routines that deal directly with the isl12022 hardware, we use
143 * rtc_time -- month 0-11, hour 0-23, yr = calendar year-epoch.
144 */
145static int isl12022_rtc_read_time(struct device *dev, struct rtc_time *tm)
146{
147 struct isl12022 *isl12022 = dev_get_drvdata(dev);
148 struct regmap *regmap = isl12022->regmap;
149 uint8_t buf[ISL12022_REG_INT + 1];
150 int ret;
151
152 ret = regmap_bulk_read(regmap, ISL12022_REG_SC, buf, sizeof(buf));
153 if (ret)
154 return ret;
155
156 if (buf[ISL12022_REG_SR] & (ISL12022_SR_LBAT85 | ISL12022_SR_LBAT75)) {
157 dev_warn(dev,
158 "voltage dropped below %u%%, "
159 "date and time is not reliable.\n",
160 buf[ISL12022_REG_SR] & ISL12022_SR_LBAT85 ? 85 : 75);
161 }
162
163 dev_dbg(dev,
164 "%s: raw data is sec=%02x, min=%02x, hr=%02x, "
165 "mday=%02x, mon=%02x, year=%02x, wday=%02x, "
166 "sr=%02x, int=%02x",
167 __func__,
168 buf[ISL12022_REG_SC],
169 buf[ISL12022_REG_MN],
170 buf[ISL12022_REG_HR],
171 buf[ISL12022_REG_DT],
172 buf[ISL12022_REG_MO],
173 buf[ISL12022_REG_YR],
174 buf[ISL12022_REG_DW],
175 buf[ISL12022_REG_SR],
176 buf[ISL12022_REG_INT]);
177
178 tm->tm_sec = bcd2bin(buf[ISL12022_REG_SC] & 0x7F);
179 tm->tm_min = bcd2bin(buf[ISL12022_REG_MN] & 0x7F);
180 tm->tm_hour = bcd2bin(buf[ISL12022_REG_HR] & 0x3F);
181 tm->tm_mday = bcd2bin(buf[ISL12022_REG_DT] & 0x3F);
182 tm->tm_wday = buf[ISL12022_REG_DW] & 0x07;
183 tm->tm_mon = bcd2bin(buf[ISL12022_REG_MO] & 0x1F) - 1;
184 tm->tm_year = bcd2bin(buf[ISL12022_REG_YR]) + 100;
185
186 dev_dbg(dev, "%s: %ptR\n", __func__, tm);
187
188 return 0;
189}
190
191static int isl12022_rtc_set_time(struct device *dev, struct rtc_time *tm)
192{
193 struct isl12022 *isl12022 = dev_get_drvdata(dev);
194 struct regmap *regmap = isl12022->regmap;
195 int ret;
196 uint8_t buf[ISL12022_REG_DW + 1];
197
198 dev_dbg(dev, "%s: %ptR\n", __func__, tm);
199
200 /* Ensure the write enable bit is set. */
201 ret = regmap_update_bits(regmap, ISL12022_REG_INT,
202 ISL12022_INT_WRTC, ISL12022_INT_WRTC);
203 if (ret)
204 return ret;
205
206 /* hours, minutes and seconds */
207 buf[ISL12022_REG_SC] = bin2bcd(tm->tm_sec);
208 buf[ISL12022_REG_MN] = bin2bcd(tm->tm_min);
209 buf[ISL12022_REG_HR] = bin2bcd(tm->tm_hour) | ISL12022_HR_MIL;
210
211 buf[ISL12022_REG_DT] = bin2bcd(tm->tm_mday);
212
213 /* month, 1 - 12 */
214 buf[ISL12022_REG_MO] = bin2bcd(tm->tm_mon + 1);
215
216 /* year and century */
217 buf[ISL12022_REG_YR] = bin2bcd(tm->tm_year % 100);
218
219 buf[ISL12022_REG_DW] = tm->tm_wday & 0x07;
220
221 return regmap_bulk_write(isl12022->regmap, ISL12022_REG_SC,
222 buf, sizeof(buf));
223}
224
225static const struct rtc_class_ops isl12022_rtc_ops = {
226 .read_time = isl12022_rtc_read_time,
227 .set_time = isl12022_rtc_set_time,
228};
229
230static const struct regmap_config regmap_config = {
231 .reg_bits = 8,
232 .val_bits = 8,
233 .use_single_write = true,
234};
235
236static int isl12022_probe(struct i2c_client *client)
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 dev_set_drvdata(&client->dev, isl12022);
248
249 isl12022->regmap = devm_regmap_init_i2c(client, ®map_config);
250 if (IS_ERR(isl12022->regmap)) {
251 dev_err(&client->dev, "regmap allocation failed\n");
252 return PTR_ERR(isl12022->regmap);
253 }
254
255 isl12022_hwmon_register(&client->dev);
256
257 isl12022->rtc = devm_rtc_allocate_device(&client->dev);
258 if (IS_ERR(isl12022->rtc))
259 return PTR_ERR(isl12022->rtc);
260
261 isl12022->rtc->ops = &isl12022_rtc_ops;
262 isl12022->rtc->range_min = RTC_TIMESTAMP_BEGIN_2000;
263 isl12022->rtc->range_max = RTC_TIMESTAMP_END_2099;
264
265 return devm_rtc_register_device(isl12022->rtc);
266}
267
268#ifdef CONFIG_OF
269static const struct of_device_id isl12022_dt_match[] = {
270 { .compatible = "isl,isl12022" }, /* for backward compat., don't use */
271 { .compatible = "isil,isl12022" },
272 { },
273};
274MODULE_DEVICE_TABLE(of, isl12022_dt_match);
275#endif
276
277static const struct i2c_device_id isl12022_id[] = {
278 { "isl12022", 0 },
279 { }
280};
281MODULE_DEVICE_TABLE(i2c, isl12022_id);
282
283static struct i2c_driver isl12022_driver = {
284 .driver = {
285 .name = "rtc-isl12022",
286#ifdef CONFIG_OF
287 .of_match_table = of_match_ptr(isl12022_dt_match),
288#endif
289 },
290 .probe_new = isl12022_probe,
291 .id_table = isl12022_id,
292};
293
294module_i2c_driver(isl12022_driver);
295
296MODULE_AUTHOR("roman.fietze@telemotive.de");
297MODULE_DESCRIPTION("ISL 12022 RTC driver");
298MODULE_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_rtc_read_time(struct device *dev, struct rtc_time *tm)
108{
109 struct i2c_client *client = to_i2c_client(dev);
110 uint8_t buf[ISL12022_REG_INT + 1];
111 int ret;
112
113 ret = isl12022_read_regs(client, ISL12022_REG_SC, buf, sizeof(buf));
114 if (ret)
115 return ret;
116
117 if (buf[ISL12022_REG_SR] & (ISL12022_SR_LBAT85 | ISL12022_SR_LBAT75)) {
118 dev_warn(&client->dev,
119 "voltage dropped below %u%%, "
120 "date and time is not reliable.\n",
121 buf[ISL12022_REG_SR] & ISL12022_SR_LBAT85 ? 85 : 75);
122 }
123
124 dev_dbg(&client->dev,
125 "%s: raw data is sec=%02x, min=%02x, hr=%02x, "
126 "mday=%02x, mon=%02x, year=%02x, wday=%02x, "
127 "sr=%02x, int=%02x",
128 __func__,
129 buf[ISL12022_REG_SC],
130 buf[ISL12022_REG_MN],
131 buf[ISL12022_REG_HR],
132 buf[ISL12022_REG_DT],
133 buf[ISL12022_REG_MO],
134 buf[ISL12022_REG_YR],
135 buf[ISL12022_REG_DW],
136 buf[ISL12022_REG_SR],
137 buf[ISL12022_REG_INT]);
138
139 tm->tm_sec = bcd2bin(buf[ISL12022_REG_SC] & 0x7F);
140 tm->tm_min = bcd2bin(buf[ISL12022_REG_MN] & 0x7F);
141 tm->tm_hour = bcd2bin(buf[ISL12022_REG_HR] & 0x3F);
142 tm->tm_mday = bcd2bin(buf[ISL12022_REG_DT] & 0x3F);
143 tm->tm_wday = buf[ISL12022_REG_DW] & 0x07;
144 tm->tm_mon = bcd2bin(buf[ISL12022_REG_MO] & 0x1F) - 1;
145 tm->tm_year = bcd2bin(buf[ISL12022_REG_YR]) + 100;
146
147 dev_dbg(&client->dev, "%s: secs=%d, mins=%d, hours=%d, "
148 "mday=%d, mon=%d, year=%d, wday=%d\n",
149 __func__,
150 tm->tm_sec, tm->tm_min, tm->tm_hour,
151 tm->tm_mday, tm->tm_mon, tm->tm_year, tm->tm_wday);
152
153 return 0;
154}
155
156static int isl12022_rtc_set_time(struct device *dev, struct rtc_time *tm)
157{
158 struct i2c_client *client = to_i2c_client(dev);
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 = true;
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 const struct rtc_class_ops isl12022_rtc_ops = {
234 .read_time = isl12022_rtc_read_time,
235 .set_time = isl12022_rtc_set_time,
236};
237
238static int isl12022_probe(struct i2c_client *client,
239 const struct i2c_device_id *id)
240{
241 struct isl12022 *isl12022;
242
243 if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C))
244 return -ENODEV;
245
246 isl12022 = devm_kzalloc(&client->dev, sizeof(struct isl12022),
247 GFP_KERNEL);
248 if (!isl12022)
249 return -ENOMEM;
250
251 i2c_set_clientdata(client, isl12022);
252
253 isl12022->rtc = devm_rtc_device_register(&client->dev,
254 isl12022_driver.driver.name,
255 &isl12022_rtc_ops, THIS_MODULE);
256 return PTR_ERR_OR_ZERO(isl12022->rtc);
257}
258
259#ifdef CONFIG_OF
260static const struct of_device_id isl12022_dt_match[] = {
261 { .compatible = "isl,isl12022" }, /* for backward compat., don't use */
262 { .compatible = "isil,isl12022" },
263 { },
264};
265MODULE_DEVICE_TABLE(of, isl12022_dt_match);
266#endif
267
268static const struct i2c_device_id isl12022_id[] = {
269 { "isl12022", 0 },
270 { }
271};
272MODULE_DEVICE_TABLE(i2c, isl12022_id);
273
274static struct i2c_driver isl12022_driver = {
275 .driver = {
276 .name = "rtc-isl12022",
277#ifdef CONFIG_OF
278 .of_match_table = of_match_ptr(isl12022_dt_match),
279#endif
280 },
281 .probe = isl12022_probe,
282 .id_table = isl12022_id,
283};
284
285module_i2c_driver(isl12022_driver);
286
287MODULE_AUTHOR("roman.fietze@telemotive.de");
288MODULE_DESCRIPTION("ISL 12022 RTC driver");
289MODULE_LICENSE("GPL");