Commit | Line | Data |
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d2912cb1 | 1 | // SPDX-License-Identifier: GPL-2.0-only |
75b61022 | 2 | /* |
2805b969 MD |
3 | * Driver for Epson RTC-9701JE |
4 | * | |
5 | * Copyright (C) 2008 Magnus Damm | |
6 | * | |
75b61022 | 7 | * Based on rtc-max6902.c |
2805b969 MD |
8 | * |
9 | * Copyright (C) 2006 8D Technologies inc. | |
10 | * Copyright (C) 2004 Compulab Ltd. | |
2805b969 MD |
11 | */ |
12 | ||
13 | #include <linux/module.h> | |
2805b969 MD |
14 | #include <linux/kernel.h> |
15 | #include <linux/platform_device.h> | |
16 | #include <linux/device.h> | |
17 | #include <linux/init.h> | |
18 | #include <linux/rtc.h> | |
19 | #include <linux/spi/spi.h> | |
20 | #include <linux/bcd.h> | |
21 | #include <linux/delay.h> | |
22 | #include <linux/bitops.h> | |
23 | ||
24 | #define RSECCNT 0x00 /* Second Counter */ | |
25 | #define RMINCNT 0x01 /* Minute Counter */ | |
26 | #define RHRCNT 0x02 /* Hour Counter */ | |
27 | #define RWKCNT 0x03 /* Week Counter */ | |
28 | #define RDAYCNT 0x04 /* Day Counter */ | |
29 | #define RMONCNT 0x05 /* Month Counter */ | |
30 | #define RYRCNT 0x06 /* Year Counter */ | |
31 | #define R100CNT 0x07 /* Y100 Counter */ | |
32 | #define RMINAR 0x08 /* Minute Alarm */ | |
33 | #define RHRAR 0x09 /* Hour Alarm */ | |
34 | #define RWKAR 0x0a /* Week/Day Alarm */ | |
35 | #define RTIMCNT 0x0c /* Interval Timer */ | |
36 | #define REXT 0x0d /* Extension Register */ | |
37 | #define RFLAG 0x0e /* RTC Flag Register */ | |
38 | #define RCR 0x0f /* RTC Control Register */ | |
39 | ||
40 | static int write_reg(struct device *dev, int address, unsigned char data) | |
41 | { | |
42 | struct spi_device *spi = to_spi_device(dev); | |
43 | unsigned char buf[2]; | |
44 | ||
45 | buf[0] = address & 0x7f; | |
46 | buf[1] = data; | |
47 | ||
48 | return spi_write(spi, buf, ARRAY_SIZE(buf)); | |
49 | } | |
50 | ||
51 | static int read_regs(struct device *dev, unsigned char *regs, int no_regs) | |
52 | { | |
53 | struct spi_device *spi = to_spi_device(dev); | |
54 | u8 txbuf[1], rxbuf[1]; | |
55 | int k, ret; | |
56 | ||
57 | ret = 0; | |
58 | ||
59 | for (k = 0; ret == 0 && k < no_regs; k++) { | |
60 | txbuf[0] = 0x80 | regs[k]; | |
61 | ret = spi_write_then_read(spi, txbuf, 1, rxbuf, 1); | |
62 | regs[k] = rxbuf[0]; | |
63 | } | |
64 | ||
65 | return ret; | |
66 | } | |
67 | ||
68 | static int r9701_get_datetime(struct device *dev, struct rtc_time *dt) | |
69 | { | |
2805b969 MD |
70 | int ret; |
71 | unsigned char buf[] = { RSECCNT, RMINCNT, RHRCNT, | |
72 | RDAYCNT, RMONCNT, RYRCNT }; | |
73 | ||
75b61022 | 74 | ret = read_regs(dev, buf, ARRAY_SIZE(buf)); |
2805b969 MD |
75 | if (ret) |
76 | return ret; | |
77 | ||
fe20ba70 AB |
78 | dt->tm_sec = bcd2bin(buf[0]); /* RSECCNT */ |
79 | dt->tm_min = bcd2bin(buf[1]); /* RMINCNT */ | |
80 | dt->tm_hour = bcd2bin(buf[2]); /* RHRCNT */ | |
2805b969 | 81 | |
fe20ba70 AB |
82 | dt->tm_mday = bcd2bin(buf[3]); /* RDAYCNT */ |
83 | dt->tm_mon = bcd2bin(buf[4]) - 1; /* RMONCNT */ | |
84 | dt->tm_year = bcd2bin(buf[5]) + 100; /* RYRCNT */ | |
2805b969 | 85 | |
22652ba7 | 86 | return 0; |
2805b969 MD |
87 | } |
88 | ||
89 | static int r9701_set_datetime(struct device *dev, struct rtc_time *dt) | |
90 | { | |
35331b50 | 91 | int ret; |
2805b969 | 92 | |
fe20ba70 AB |
93 | ret = write_reg(dev, RHRCNT, bin2bcd(dt->tm_hour)); |
94 | ret = ret ? ret : write_reg(dev, RMINCNT, bin2bcd(dt->tm_min)); | |
95 | ret = ret ? ret : write_reg(dev, RSECCNT, bin2bcd(dt->tm_sec)); | |
96 | ret = ret ? ret : write_reg(dev, RDAYCNT, bin2bcd(dt->tm_mday)); | |
97 | ret = ret ? ret : write_reg(dev, RMONCNT, bin2bcd(dt->tm_mon + 1)); | |
98 | ret = ret ? ret : write_reg(dev, RYRCNT, bin2bcd(dt->tm_year - 100)); | |
2805b969 MD |
99 | |
100 | return ret; | |
101 | } | |
102 | ||
103 | static const struct rtc_class_ops r9701_rtc_ops = { | |
104 | .read_time = r9701_get_datetime, | |
105 | .set_time = r9701_set_datetime, | |
106 | }; | |
107 | ||
5a167f45 | 108 | static int r9701_probe(struct spi_device *spi) |
2805b969 MD |
109 | { |
110 | struct rtc_device *rtc; | |
111 | unsigned char tmp; | |
112 | int res; | |
113 | ||
73737b87 AG |
114 | tmp = R100CNT; |
115 | res = read_regs(&spi->dev, &tmp, 1); | |
116 | if (res || tmp != 0x20) { | |
117 | dev_err(&spi->dev, "cannot read RTC register\n"); | |
118 | return -ENODEV; | |
119 | } | |
120 | ||
dfe13cf2 | 121 | rtc = devm_rtc_allocate_device(&spi->dev); |
2805b969 MD |
122 | if (IS_ERR(rtc)) |
123 | return PTR_ERR(rtc); | |
124 | ||
fbf52c0d | 125 | spi_set_drvdata(spi, rtc); |
dfe13cf2 | 126 | rtc->ops = &r9701_rtc_ops; |
35331b50 AB |
127 | rtc->range_min = RTC_TIMESTAMP_BEGIN_2000; |
128 | rtc->range_max = RTC_TIMESTAMP_END_2099; | |
2805b969 | 129 | |
fdcfd854 | 130 | return devm_rtc_register_device(rtc); |
2805b969 MD |
131 | } |
132 | ||
2805b969 MD |
133 | static struct spi_driver r9701_driver = { |
134 | .driver = { | |
135 | .name = "rtc-r9701", | |
2805b969 MD |
136 | }, |
137 | .probe = r9701_probe, | |
2805b969 MD |
138 | }; |
139 | ||
109e9418 | 140 | module_spi_driver(r9701_driver); |
2805b969 MD |
141 | |
142 | MODULE_DESCRIPTION("r9701 spi RTC driver"); | |
143 | MODULE_AUTHOR("Magnus Damm <damm@opensource.se>"); | |
144 | MODULE_LICENSE("GPL"); | |
e0626e38 | 145 | MODULE_ALIAS("spi:rtc-r9701"); |