]> Git Repo - J-linux.git/blob - drivers/rtc/rtc-sd2405al.c
Merge tag 'vfs-6.13-rc7.fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs
[J-linux.git] / drivers / rtc / rtc-sd2405al.c
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  * RTC driver for the SD2405AL Real-Time Clock
4  *
5  * Datasheet:
6  * https://image.dfrobot.com/image/data/TOY0021/SD2405AL%20datasheet%20(Angelo%20v0.1).pdf
7  *
8  * Copyright (C) 2024 Tóth János <[email protected]>
9  */
10
11 #include <linux/bcd.h>
12 #include <linux/i2c.h>
13 #include <linux/regmap.h>
14 #include <linux/rtc.h>
15
16 /* Real time clock registers */
17 #define SD2405AL_REG_T_SEC      0x00
18 #define SD2405AL_REG_T_MIN      0x01
19 #define SD2405AL_REG_T_HOUR     0x02
20 #       define SD2405AL_BIT_12H_PM      BIT(5)
21 #       define SD2405AL_BIT_24H         BIT(7)
22 #define SD2405AL_REG_T_WEEK     0x03
23 #define SD2405AL_REG_T_DAY      0x04
24 #define SD2405AL_REG_T_MON      0x05
25 #define SD2405AL_REG_T_YEAR     0x06
26
27 #define SD2405AL_NUM_T_REGS     (SD2405AL_REG_T_YEAR - SD2405AL_REG_T_SEC + 1)
28
29 /* Control registers */
30 #define SD2405AL_REG_CTR1       0x0F
31 #       define SD2405AL_BIT_WRTC2       BIT(2)
32 #       define SD2405AL_BIT_WRTC3       BIT(7)
33 #define SD2405AL_REG_CTR2       0x10
34 #       define SD2405AL_BIT_WRTC1       BIT(7)
35 #define SD2405AL_REG_CTR3       0x11
36 #define SD2405AL_REG_TTF        0x12
37 #define SD2405AL_REG_CNTDWN     0x13
38
39 /* General RAM */
40 #define SD2405AL_REG_M_START    0x14
41 #define SD2405AL_REG_M_END      0x1F
42
43 struct sd2405al {
44         struct device           *dev;
45         struct rtc_device       *rtc;
46         struct regmap           *regmap;
47 };
48
49 static int sd2405al_enable_reg_write(struct sd2405al *sd2405al)
50 {
51         int ret;
52
53         /* order of writes is important */
54         ret = regmap_update_bits(sd2405al->regmap, SD2405AL_REG_CTR2,
55                                  SD2405AL_BIT_WRTC1, SD2405AL_BIT_WRTC1);
56         if (ret < 0)
57                 return ret;
58
59         ret = regmap_update_bits(sd2405al->regmap, SD2405AL_REG_CTR1,
60                                  SD2405AL_BIT_WRTC2 | SD2405AL_BIT_WRTC3,
61                                  SD2405AL_BIT_WRTC2 | SD2405AL_BIT_WRTC3);
62         if (ret < 0)
63                 return ret;
64
65         return 0;
66 }
67
68 static int sd2405al_disable_reg_write(struct sd2405al *sd2405al)
69 {
70         int ret;
71
72         /* order of writes is important */
73         ret = regmap_update_bits(sd2405al->regmap, SD2405AL_REG_CTR1,
74                                  SD2405AL_BIT_WRTC2 | SD2405AL_BIT_WRTC3, 0x00);
75         if (ret < 0)
76                 return ret;
77
78         ret = regmap_update_bits(sd2405al->regmap, SD2405AL_REG_CTR2,
79                                  SD2405AL_BIT_WRTC1, 0x00);
80         if (ret < 0)
81                 return ret;
82
83         return 0;
84 }
85
86 static int sd2405al_read_time(struct device *dev, struct rtc_time *time)
87 {
88         u8 data[SD2405AL_NUM_T_REGS] = { 0 };
89         struct sd2405al *sd2405al = dev_get_drvdata(dev);
90         int ret;
91
92         ret = regmap_bulk_read(sd2405al->regmap, SD2405AL_REG_T_SEC, data,
93                                SD2405AL_NUM_T_REGS);
94         if (ret < 0)
95                 return ret;
96
97         time->tm_sec = bcd2bin(data[SD2405AL_REG_T_SEC] & 0x7F);
98         time->tm_min = bcd2bin(data[SD2405AL_REG_T_MIN] & 0x7F);
99
100         if (data[SD2405AL_REG_T_HOUR] & SD2405AL_BIT_24H)
101                 time->tm_hour = bcd2bin(data[SD2405AL_REG_T_HOUR] & 0x3F);
102         else
103                 if (data[SD2405AL_REG_T_HOUR] & SD2405AL_BIT_12H_PM)
104                         time->tm_hour = bcd2bin(data[SD2405AL_REG_T_HOUR]
105                                                 & 0x1F) + 12;
106                 else /* 12 hour mode, AM */
107                         time->tm_hour = bcd2bin(data[SD2405AL_REG_T_HOUR]
108                                                 & 0x1F);
109
110         time->tm_wday = bcd2bin(data[SD2405AL_REG_T_WEEK] & 0x07);
111         time->tm_mday = bcd2bin(data[SD2405AL_REG_T_DAY] & 0x3F);
112         time->tm_mon = bcd2bin(data[SD2405AL_REG_T_MON] & 0x1F) - 1;
113         time->tm_year = bcd2bin(data[SD2405AL_REG_T_YEAR]) + 100;
114
115         dev_dbg(sd2405al->dev, "read time: %ptR (%d)\n", time, time->tm_wday);
116
117         return 0;
118 }
119
120 static int sd2405al_set_time(struct device *dev, struct rtc_time *time)
121 {
122         u8 data[SD2405AL_NUM_T_REGS];
123         struct sd2405al *sd2405al = dev_get_drvdata(dev);
124         int ret;
125
126         data[SD2405AL_REG_T_SEC] = bin2bcd(time->tm_sec);
127         data[SD2405AL_REG_T_MIN] = bin2bcd(time->tm_min);
128         data[SD2405AL_REG_T_HOUR] = bin2bcd(time->tm_hour) | SD2405AL_BIT_24H;
129         data[SD2405AL_REG_T_DAY] = bin2bcd(time->tm_mday);
130         data[SD2405AL_REG_T_WEEK] = bin2bcd(time->tm_wday);
131         data[SD2405AL_REG_T_MON] = bin2bcd(time->tm_mon) + 1;
132         data[SD2405AL_REG_T_YEAR] = bin2bcd(time->tm_year - 100);
133
134         ret = sd2405al_enable_reg_write(sd2405al);
135         if (ret < 0)
136                 return ret;
137
138         ret = regmap_bulk_write(sd2405al->regmap, SD2405AL_REG_T_SEC, data,
139                                 SD2405AL_NUM_T_REGS);
140         if (ret < 0)
141                 return ret;
142
143         ret = regmap_write(sd2405al->regmap, SD2405AL_REG_TTF, 0x00);
144         if (ret < 0)
145                 return ret;
146
147         ret = sd2405al_disable_reg_write(sd2405al);
148         if (ret < 0)
149                 return ret;
150
151         dev_dbg(sd2405al->dev, "set time: %ptR (%d)\n", time, time->tm_wday);
152
153         return 0;
154 }
155
156 static const struct rtc_class_ops sd2405al_rtc_ops = {
157         .read_time = sd2405al_read_time,
158         .set_time = sd2405al_set_time,
159 };
160
161 static const struct regmap_config sd2405al_regmap_conf = {
162         .reg_bits = 8,
163         .val_bits = 8,
164         .max_register = SD2405AL_REG_M_END,
165 };
166
167 static int sd2405al_probe(struct i2c_client *client)
168 {
169         struct sd2405al *sd2405al;
170         int ret;
171
172         if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C))
173                 return -ENODEV;
174
175         sd2405al = devm_kzalloc(&client->dev, sizeof(*sd2405al), GFP_KERNEL);
176         if (!sd2405al)
177                 return -ENOMEM;
178
179         sd2405al->dev = &client->dev;
180
181         sd2405al->regmap = devm_regmap_init_i2c(client, &sd2405al_regmap_conf);
182         if (IS_ERR(sd2405al->regmap))
183                 return PTR_ERR(sd2405al->regmap);
184
185         sd2405al->rtc = devm_rtc_allocate_device(&client->dev);
186         if (IS_ERR(sd2405al->rtc))
187                 return PTR_ERR(sd2405al->rtc);
188
189         sd2405al->rtc->ops = &sd2405al_rtc_ops;
190         sd2405al->rtc->range_min = RTC_TIMESTAMP_BEGIN_2000;
191         sd2405al->rtc->range_max = RTC_TIMESTAMP_END_2099;
192
193         dev_set_drvdata(&client->dev, sd2405al);
194
195         ret = devm_rtc_register_device(sd2405al->rtc);
196         if (ret < 0)
197                 return ret;
198
199         return 0;
200 }
201
202 static const struct i2c_device_id sd2405al_id[] = {
203         { "sd2405al" },
204         { /* sentinel */ }
205 };
206 MODULE_DEVICE_TABLE(i2c, sd2405al_id);
207
208 static const __maybe_unused struct of_device_id sd2405al_of_match[] = {
209         { .compatible = "dfrobot,sd2405al" },
210         { /* sentinel */ }
211 };
212 MODULE_DEVICE_TABLE(of, sd2405al_of_match);
213
214 static struct i2c_driver sd2405al_driver = {
215         .driver = {
216                 .name = "sd2405al",
217                 .of_match_table = of_match_ptr(sd2405al_of_match),
218         },
219         .probe = sd2405al_probe,
220         .id_table = sd2405al_id,
221 };
222
223 module_i2c_driver(sd2405al_driver);
224
225 MODULE_AUTHOR("Tóth János <[email protected]>");
226 MODULE_LICENSE("GPL");
227 MODULE_DESCRIPTION("SD2405AL RTC driver");
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