blob: ee3ba7e6b45e148d3f03c9d671ddefbcbc02f282 [file] [log] [blame]
Roman Fietzed6c74282010-08-10 18:02:14 -07001/*
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>
Paul Gortmaker21138522011-05-27 09:57:25 -040018#include <linux/module.h>
Sachin Kamat17cc54b22013-07-03 15:07:49 -070019#include <linux/err.h>
Stuart Longlanddb04d622014-08-08 14:20:20 -070020#include <linux/of.h>
21#include <linux/of_device.h>
Roman Fietzed6c74282010-08-10 18:02:14 -070022
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 /* The clock can give out invalid datetime, but we cannot return
155 * -EINVAL otherwise hwclock will refuse to set the time on bootup. */
156 if (rtc_valid_tm(tm) < 0)
157 dev_err(&client->dev, "retrieved date and time is invalid.\n");
158
159 return 0;
160}
161
162static int isl12022_set_datetime(struct i2c_client *client, struct rtc_time *tm)
163{
164 struct isl12022 *isl12022 = i2c_get_clientdata(client);
165 size_t i;
166 int ret;
167 uint8_t buf[ISL12022_REG_DW + 1];
168
169 dev_dbg(&client->dev, "%s: secs=%d, mins=%d, hours=%d, "
170 "mday=%d, mon=%d, year=%d, wday=%d\n",
171 __func__,
172 tm->tm_sec, tm->tm_min, tm->tm_hour,
173 tm->tm_mday, tm->tm_mon, tm->tm_year, tm->tm_wday);
174
175 if (!isl12022->write_enabled) {
176
177 ret = isl12022_read_regs(client, ISL12022_REG_INT, buf, 1);
178 if (ret)
179 return ret;
180
181 /* Check if WRTC (write rtc enable) is set factory default is
182 * 0 (not set) */
183 if (!(buf[0] & ISL12022_INT_WRTC)) {
184 dev_info(&client->dev,
185 "init write enable and 24 hour format\n");
186
187 /* Set the write enable bit. */
188 ret = isl12022_write_reg(client,
189 ISL12022_REG_INT,
190 buf[0] | ISL12022_INT_WRTC);
191 if (ret)
192 return ret;
193
194 /* Write to any RTC register to start RTC, we use the
195 * HR register, setting the MIL bit to use the 24 hour
196 * format. */
197 ret = isl12022_read_regs(client, ISL12022_REG_HR,
198 buf, 1);
199 if (ret)
200 return ret;
201
202 ret = isl12022_write_reg(client,
203 ISL12022_REG_HR,
204 buf[0] | ISL12022_HR_MIL);
205 if (ret)
206 return ret;
207 }
208
209 isl12022->write_enabled = 1;
210 }
211
212 /* hours, minutes and seconds */
213 buf[ISL12022_REG_SC] = bin2bcd(tm->tm_sec);
214 buf[ISL12022_REG_MN] = bin2bcd(tm->tm_min);
Roman Fietze6d23b252010-08-10 18:02:21 -0700215 buf[ISL12022_REG_HR] = bin2bcd(tm->tm_hour) | ISL12022_HR_MIL;
Roman Fietzed6c74282010-08-10 18:02:14 -0700216
217 buf[ISL12022_REG_DT] = bin2bcd(tm->tm_mday);
218
219 /* month, 1 - 12 */
220 buf[ISL12022_REG_MO] = bin2bcd(tm->tm_mon + 1);
221
222 /* year and century */
223 buf[ISL12022_REG_YR] = bin2bcd(tm->tm_year % 100);
224
225 buf[ISL12022_REG_DW] = tm->tm_wday & 0x07;
226
227 /* write register's data */
228 for (i = 0; i < ARRAY_SIZE(buf); i++) {
229 ret = isl12022_write_reg(client, ISL12022_REG_SC + i,
230 buf[ISL12022_REG_SC + i]);
231 if (ret)
232 return -EIO;
Peter Senna Tschudin0b7e0392013-02-21 16:44:30 -0800233 }
Roman Fietzed6c74282010-08-10 18:02:14 -0700234
235 return 0;
236}
237
238static int isl12022_rtc_read_time(struct device *dev, struct rtc_time *tm)
239{
240 return isl12022_get_datetime(to_i2c_client(dev), tm);
241}
242
243static int isl12022_rtc_set_time(struct device *dev, struct rtc_time *tm)
244{
245 return isl12022_set_datetime(to_i2c_client(dev), tm);
246}
247
248static const struct rtc_class_ops isl12022_rtc_ops = {
249 .read_time = isl12022_rtc_read_time,
250 .set_time = isl12022_rtc_set_time,
251};
252
253static int isl12022_probe(struct i2c_client *client,
254 const struct i2c_device_id *id)
255{
256 struct isl12022 *isl12022;
257
Roman Fietzed6c74282010-08-10 18:02:14 -0700258 if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C))
259 return -ENODEV;
260
Jingoo Handc831f92013-04-29 16:20:41 -0700261 isl12022 = devm_kzalloc(&client->dev, sizeof(struct isl12022),
262 GFP_KERNEL);
Roman Fietzed6c74282010-08-10 18:02:14 -0700263 if (!isl12022)
264 return -ENOMEM;
265
266 dev_dbg(&client->dev, "chip found, driver version " DRV_VERSION "\n");
267
268 i2c_set_clientdata(client, isl12022);
269
Jingoo Handc831f92013-04-29 16:20:41 -0700270 isl12022->rtc = devm_rtc_device_register(&client->dev,
271 isl12022_driver.driver.name,
272 &isl12022_rtc_ops, THIS_MODULE);
Sachin Kamatdac30a92013-07-15 15:43:32 +0530273 return PTR_ERR_OR_ZERO(isl12022->rtc);
Roman Fietzed6c74282010-08-10 18:02:14 -0700274}
275
Stuart Longlanddb04d622014-08-08 14:20:20 -0700276#ifdef CONFIG_OF
Uwe Kleine-Königa28885b2014-10-13 15:52:39 -0700277static const struct of_device_id isl12022_dt_match[] = {
Stuart Longlanddb04d622014-08-08 14:20:20 -0700278 { .compatible = "isl,isl12022" },
279 { },
280};
281#endif
282
Roman Fietzed6c74282010-08-10 18:02:14 -0700283static const struct i2c_device_id isl12022_id[] = {
284 { "isl12022", 0 },
Roman Fietzed6c74282010-08-10 18:02:14 -0700285 { }
286};
287MODULE_DEVICE_TABLE(i2c, isl12022_id);
288
289static struct i2c_driver isl12022_driver = {
290 .driver = {
291 .name = "rtc-isl12022",
Stuart Longlanddb04d622014-08-08 14:20:20 -0700292#ifdef CONFIG_OF
293 .of_match_table = of_match_ptr(isl12022_dt_match),
294#endif
Roman Fietzed6c74282010-08-10 18:02:14 -0700295 },
296 .probe = isl12022_probe,
Roman Fietzed6c74282010-08-10 18:02:14 -0700297 .id_table = isl12022_id,
298};
299
Axel Lin0abc9202012-03-23 15:02:31 -0700300module_i2c_driver(isl12022_driver);
Roman Fietzed6c74282010-08-10 18:02:14 -0700301
302MODULE_AUTHOR("roman.fietze@telemotive.de");
303MODULE_DESCRIPTION("ISL 12022 RTC driver");
304MODULE_LICENSE("GPL");
305MODULE_VERSION(DRV_VERSION);