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d2912cb1 | 1 | // SPDX-License-Identifier: GPL-2.0-only |
617b26a0 RG |
2 | /* rtc-ds1347.c |
3 | * | |
4 | * Driver for Dallas Semiconductor DS1347 Low Current, SPI Compatible | |
5 | * Real Time Clock | |
6 | * | |
7 | * Author : Raghavendra Chandra Ganiga <ravi23ganiga@gmail.com> | |
617b26a0 RG |
8 | */ |
9 | ||
10 | #include <linux/init.h> | |
11 | #include <linux/module.h> | |
12 | #include <linux/device.h> | |
13 | #include <linux/platform_device.h> | |
14 | #include <linux/rtc.h> | |
15 | #include <linux/spi/spi.h> | |
16 | #include <linux/bcd.h> | |
ee85bb5b | 17 | #include <linux/regmap.h> |
617b26a0 RG |
18 | |
19 | /* Registers in ds1347 rtc */ | |
20 | ||
21 | #define DS1347_SECONDS_REG 0x01 | |
22 | #define DS1347_MINUTES_REG 0x03 | |
23 | #define DS1347_HOURS_REG 0x05 | |
24 | #define DS1347_DATE_REG 0x07 | |
25 | #define DS1347_MONTH_REG 0x09 | |
26 | #define DS1347_DAY_REG 0x0B | |
27 | #define DS1347_YEAR_REG 0x0D | |
28 | #define DS1347_CONTROL_REG 0x0F | |
147dae76 | 29 | #define DS1347_CENTURY_REG 0x13 |
617b26a0 RG |
30 | #define DS1347_STATUS_REG 0x17 |
31 | #define DS1347_CLOCK_BURST 0x3F | |
32 | ||
860c45b5 AB |
33 | #define DS1347_WP_BIT BIT(7) |
34 | ||
d9dcfa5f AB |
35 | #define DS1347_NEOSC_BIT BIT(7) |
36 | #define DS1347_OSF_BIT BIT(2) | |
37 | ||
ee85bb5b RG |
38 | static const struct regmap_range ds1347_ranges[] = { |
39 | { | |
40 | .range_min = DS1347_SECONDS_REG, | |
41 | .range_max = DS1347_STATUS_REG, | |
42 | }, | |
43 | }; | |
617b26a0 | 44 | |
ee85bb5b RG |
45 | static const struct regmap_access_table ds1347_access_table = { |
46 | .yes_ranges = ds1347_ranges, | |
47 | .n_yes_ranges = ARRAY_SIZE(ds1347_ranges), | |
48 | }; | |
617b26a0 RG |
49 | |
50 | static int ds1347_read_time(struct device *dev, struct rtc_time *dt) | |
51 | { | |
ff7f9e05 | 52 | struct regmap *map = dev_get_drvdata(dev); |
147dae76 | 53 | unsigned int status, century, secs; |
617b26a0 | 54 | unsigned char buf[8]; |
147dae76 | 55 | int err; |
617b26a0 | 56 | |
d9dcfa5f AB |
57 | err = regmap_read(map, DS1347_STATUS_REG, &status); |
58 | if (err) | |
59 | return err; | |
60 | ||
61 | if (status & DS1347_OSF_BIT) | |
62 | return -EINVAL; | |
63 | ||
147dae76 AB |
64 | do { |
65 | err = regmap_bulk_read(map, DS1347_CLOCK_BURST, buf, 8); | |
66 | if (err) | |
67 | return err; | |
68 | ||
69 | err = regmap_read(map, DS1347_CENTURY_REG, ¢ury); | |
70 | if (err) | |
71 | return err; | |
72 | ||
73 | err = regmap_read(map, DS1347_SECONDS_REG, &secs); | |
74 | if (err) | |
75 | return err; | |
76 | } while (buf[0] != secs); | |
617b26a0 RG |
77 | |
78 | dt->tm_sec = bcd2bin(buf[0]); | |
088443c7 | 79 | dt->tm_min = bcd2bin(buf[1] & 0x7f); |
617b26a0 RG |
80 | dt->tm_hour = bcd2bin(buf[2] & 0x3F); |
81 | dt->tm_mday = bcd2bin(buf[3]); | |
82 | dt->tm_mon = bcd2bin(buf[4]) - 1; | |
83 | dt->tm_wday = bcd2bin(buf[5]) - 1; | |
147dae76 | 84 | dt->tm_year = (bcd2bin(century) * 100) + bcd2bin(buf[6]) - 1900; |
617b26a0 | 85 | |
22652ba7 | 86 | return 0; |
617b26a0 RG |
87 | } |
88 | ||
89 | static int ds1347_set_time(struct device *dev, struct rtc_time *dt) | |
90 | { | |
ff7f9e05 | 91 | struct regmap *map = dev_get_drvdata(dev); |
147dae76 | 92 | unsigned int century; |
ee85bb5b | 93 | unsigned char buf[8]; |
d9dcfa5f AB |
94 | int err; |
95 | ||
96 | err = regmap_update_bits(map, DS1347_STATUS_REG, | |
97 | DS1347_NEOSC_BIT, DS1347_NEOSC_BIT); | |
98 | if (err) | |
99 | return err; | |
ee85bb5b | 100 | |
ee85bb5b RG |
101 | buf[0] = bin2bcd(dt->tm_sec); |
102 | buf[1] = bin2bcd(dt->tm_min); | |
103 | buf[2] = (bin2bcd(dt->tm_hour) & 0x3F); | |
104 | buf[3] = bin2bcd(dt->tm_mday); | |
105 | buf[4] = bin2bcd(dt->tm_mon + 1); | |
106 | buf[5] = bin2bcd(dt->tm_wday + 1); | |
147dae76 | 107 | buf[6] = bin2bcd(dt->tm_year % 100); |
ee85bb5b | 108 | buf[7] = bin2bcd(0x00); |
617b26a0 | 109 | |
d9dcfa5f AB |
110 | err = regmap_bulk_write(map, DS1347_CLOCK_BURST, buf, 8); |
111 | if (err) | |
112 | return err; | |
113 | ||
147dae76 AB |
114 | century = (dt->tm_year / 100) + 19; |
115 | err = regmap_write(map, DS1347_CENTURY_REG, century); | |
116 | if (err) | |
117 | return err; | |
118 | ||
d9dcfa5f AB |
119 | return regmap_update_bits(map, DS1347_STATUS_REG, |
120 | DS1347_NEOSC_BIT | DS1347_OSF_BIT, 0); | |
617b26a0 RG |
121 | } |
122 | ||
123 | static const struct rtc_class_ops ds1347_rtc_ops = { | |
124 | .read_time = ds1347_read_time, | |
125 | .set_time = ds1347_set_time, | |
126 | }; | |
127 | ||
128 | static int ds1347_probe(struct spi_device *spi) | |
129 | { | |
130 | struct rtc_device *rtc; | |
ee85bb5b RG |
131 | struct regmap_config config; |
132 | struct regmap *map; | |
860c45b5 | 133 | int err; |
617b26a0 | 134 | |
ee85bb5b RG |
135 | memset(&config, 0, sizeof(config)); |
136 | config.reg_bits = 8; | |
137 | config.val_bits = 8; | |
138 | config.read_flag_mask = 0x80; | |
139 | config.max_register = 0x3F; | |
140 | config.wr_table = &ds1347_access_table; | |
141 | ||
617b26a0 RG |
142 | /* spi setup with ds1347 in mode 3 and bits per word as 8 */ |
143 | spi->mode = SPI_MODE_3; | |
144 | spi->bits_per_word = 8; | |
145 | spi_setup(spi); | |
146 | ||
ee85bb5b RG |
147 | map = devm_regmap_init_spi(spi, &config); |
148 | ||
149 | if (IS_ERR(map)) { | |
150 | dev_err(&spi->dev, "ds1347 regmap init spi failed\n"); | |
151 | return PTR_ERR(map); | |
152 | } | |
153 | ||
154 | spi_set_drvdata(spi, map); | |
155 | ||
617b26a0 | 156 | /* Disable the write protect of rtc */ |
860c45b5 AB |
157 | err = regmap_update_bits(map, DS1347_CONTROL_REG, DS1347_WP_BIT, 0); |
158 | if (err) | |
159 | return err; | |
617b26a0 | 160 | |
554692d5 | 161 | rtc = devm_rtc_allocate_device(&spi->dev); |
617b26a0 RG |
162 | if (IS_ERR(rtc)) |
163 | return PTR_ERR(rtc); | |
164 | ||
554692d5 | 165 | rtc->ops = &ds1347_rtc_ops; |
3ce20a23 AB |
166 | rtc->range_min = RTC_TIMESTAMP_BEGIN_0000; |
167 | rtc->range_max = RTC_TIMESTAMP_END_9999; | |
554692d5 AB |
168 | |
169 | return rtc_register_device(rtc); | |
617b26a0 RG |
170 | } |
171 | ||
172 | static struct spi_driver ds1347_driver = { | |
173 | .driver = { | |
174 | .name = "ds1347", | |
617b26a0 RG |
175 | }, |
176 | .probe = ds1347_probe, | |
177 | }; | |
178 | ||
179 | module_spi_driver(ds1347_driver); | |
180 | ||
181 | MODULE_DESCRIPTION("DS1347 SPI RTC DRIVER"); | |
182 | MODULE_AUTHOR("Raghavendra C Ganiga <ravi23ganiga@gmail.com>"); | |
183 | MODULE_LICENSE("GPL v2"); |