Commit | Line | Data |
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d2912cb1 | 1 | // SPDX-License-Identifier: GPL-2.0-only |
5ec3e4b7 AN |
2 | /* |
3 | * An rtc driver for the Dallas DS1742 | |
4 | * | |
5 | * Copyright (C) 2006 Atsushi Nemoto <anemo@mba.ocn.ne.jp> | |
6 | * | |
f9231a0c TER |
7 | * Copyright (C) 2006 Torsten Ertbjerg Rasmussen <tr@newtec.dk> |
8 | * - nvram size determined from resource | |
9 | * - this ds1742 driver now supports ds1743. | |
5ec3e4b7 AN |
10 | */ |
11 | ||
12 | #include <linux/bcd.h> | |
5ec3e4b7 | 13 | #include <linux/kernel.h> |
5a0e3ad6 | 14 | #include <linux/gfp.h> |
5ec3e4b7 AN |
15 | #include <linux/delay.h> |
16 | #include <linux/jiffies.h> | |
17 | #include <linux/rtc.h> | |
663b3524 AS |
18 | #include <linux/of.h> |
19 | #include <linux/of_device.h> | |
5ec3e4b7 AN |
20 | #include <linux/platform_device.h> |
21 | #include <linux/io.h> | |
2113852b | 22 | #include <linux/module.h> |
5ec3e4b7 | 23 | |
f9231a0c | 24 | #define RTC_SIZE 8 |
5ec3e4b7 | 25 | |
f9231a0c TER |
26 | #define RTC_CONTROL 0 |
27 | #define RTC_CENTURY 0 | |
28 | #define RTC_SECONDS 1 | |
29 | #define RTC_MINUTES 2 | |
30 | #define RTC_HOURS 3 | |
31 | #define RTC_DAY 4 | |
32 | #define RTC_DATE 5 | |
33 | #define RTC_MONTH 6 | |
34 | #define RTC_YEAR 7 | |
5ec3e4b7 AN |
35 | |
36 | #define RTC_CENTURY_MASK 0x3f | |
37 | #define RTC_SECONDS_MASK 0x7f | |
38 | #define RTC_DAY_MASK 0x07 | |
39 | ||
40 | /* Bits in the Control/Century register */ | |
41 | #define RTC_WRITE 0x80 | |
42 | #define RTC_READ 0x40 | |
43 | ||
44 | /* Bits in the Seconds register */ | |
45 | #define RTC_STOP 0x80 | |
46 | ||
47 | /* Bits in the Day register */ | |
48 | #define RTC_BATT_FLAG 0x80 | |
49 | ||
50 | struct rtc_plat_data { | |
f9231a0c TER |
51 | void __iomem *ioaddr_nvram; |
52 | void __iomem *ioaddr_rtc; | |
5ec3e4b7 AN |
53 | unsigned long last_jiffies; |
54 | }; | |
55 | ||
56 | static int ds1742_rtc_set_time(struct device *dev, struct rtc_time *tm) | |
57 | { | |
85368bb9 | 58 | struct rtc_plat_data *pdata = dev_get_drvdata(dev); |
f9231a0c | 59 | void __iomem *ioaddr = pdata->ioaddr_rtc; |
5ec3e4b7 AN |
60 | u8 century; |
61 | ||
fe20ba70 | 62 | century = bin2bcd((tm->tm_year + 1900) / 100); |
5ec3e4b7 AN |
63 | |
64 | writeb(RTC_WRITE, ioaddr + RTC_CONTROL); | |
65 | ||
fe20ba70 AB |
66 | writeb(bin2bcd(tm->tm_year % 100), ioaddr + RTC_YEAR); |
67 | writeb(bin2bcd(tm->tm_mon + 1), ioaddr + RTC_MONTH); | |
68 | writeb(bin2bcd(tm->tm_wday) & RTC_DAY_MASK, ioaddr + RTC_DAY); | |
69 | writeb(bin2bcd(tm->tm_mday), ioaddr + RTC_DATE); | |
70 | writeb(bin2bcd(tm->tm_hour), ioaddr + RTC_HOURS); | |
71 | writeb(bin2bcd(tm->tm_min), ioaddr + RTC_MINUTES); | |
72 | writeb(bin2bcd(tm->tm_sec) & RTC_SECONDS_MASK, ioaddr + RTC_SECONDS); | |
5ec3e4b7 AN |
73 | |
74 | /* RTC_CENTURY and RTC_CONTROL share same register */ | |
75 | writeb(RTC_WRITE | (century & RTC_CENTURY_MASK), ioaddr + RTC_CENTURY); | |
76 | writeb(century & RTC_CENTURY_MASK, ioaddr + RTC_CONTROL); | |
77 | return 0; | |
78 | } | |
79 | ||
80 | static int ds1742_rtc_read_time(struct device *dev, struct rtc_time *tm) | |
81 | { | |
85368bb9 | 82 | struct rtc_plat_data *pdata = dev_get_drvdata(dev); |
f9231a0c | 83 | void __iomem *ioaddr = pdata->ioaddr_rtc; |
5ec3e4b7 AN |
84 | unsigned int year, month, day, hour, minute, second, week; |
85 | unsigned int century; | |
86 | ||
87 | /* give enough time to update RTC in case of continuous read */ | |
88 | if (pdata->last_jiffies == jiffies) | |
89 | msleep(1); | |
90 | pdata->last_jiffies = jiffies; | |
91 | writeb(RTC_READ, ioaddr + RTC_CONTROL); | |
92 | second = readb(ioaddr + RTC_SECONDS) & RTC_SECONDS_MASK; | |
93 | minute = readb(ioaddr + RTC_MINUTES); | |
94 | hour = readb(ioaddr + RTC_HOURS); | |
95 | day = readb(ioaddr + RTC_DATE); | |
96 | week = readb(ioaddr + RTC_DAY) & RTC_DAY_MASK; | |
97 | month = readb(ioaddr + RTC_MONTH); | |
98 | year = readb(ioaddr + RTC_YEAR); | |
99 | century = readb(ioaddr + RTC_CENTURY) & RTC_CENTURY_MASK; | |
100 | writeb(0, ioaddr + RTC_CONTROL); | |
fe20ba70 AB |
101 | tm->tm_sec = bcd2bin(second); |
102 | tm->tm_min = bcd2bin(minute); | |
103 | tm->tm_hour = bcd2bin(hour); | |
104 | tm->tm_mday = bcd2bin(day); | |
105 | tm->tm_wday = bcd2bin(week); | |
106 | tm->tm_mon = bcd2bin(month) - 1; | |
5ec3e4b7 | 107 | /* year is 1900 + tm->tm_year */ |
fe20ba70 | 108 | tm->tm_year = bcd2bin(year) + bcd2bin(century) * 100 - 1900; |
5ec3e4b7 | 109 | |
22652ba7 | 110 | return 0; |
5ec3e4b7 AN |
111 | } |
112 | ||
ff8371ac | 113 | static const struct rtc_class_ops ds1742_rtc_ops = { |
5ec3e4b7 AN |
114 | .read_time = ds1742_rtc_read_time, |
115 | .set_time = ds1742_rtc_set_time, | |
116 | }; | |
117 | ||
87c78d95 AB |
118 | static int ds1742_nvram_read(void *priv, unsigned int pos, void *val, |
119 | size_t bytes) | |
5ec3e4b7 | 120 | { |
87c78d95 | 121 | struct rtc_plat_data *pdata = priv; |
f9231a0c | 122 | void __iomem *ioaddr = pdata->ioaddr_nvram; |
87c78d95 | 123 | u8 *buf = val; |
5ec3e4b7 | 124 | |
87c78d95 | 125 | for (; bytes; bytes--) |
5ec3e4b7 | 126 | *buf++ = readb(ioaddr + pos++); |
87c78d95 | 127 | return 0; |
5ec3e4b7 AN |
128 | } |
129 | ||
87c78d95 AB |
130 | static int ds1742_nvram_write(void *priv, unsigned int pos, void *val, |
131 | size_t bytes) | |
5ec3e4b7 | 132 | { |
87c78d95 | 133 | struct rtc_plat_data *pdata = priv; |
f9231a0c | 134 | void __iomem *ioaddr = pdata->ioaddr_nvram; |
87c78d95 | 135 | u8 *buf = val; |
5ec3e4b7 | 136 | |
87c78d95 | 137 | for (; bytes; bytes--) |
5ec3e4b7 | 138 | writeb(*buf++, ioaddr + pos++); |
87c78d95 | 139 | return 0; |
5ec3e4b7 AN |
140 | } |
141 | ||
5a167f45 | 142 | static int ds1742_rtc_probe(struct platform_device *pdev) |
5ec3e4b7 AN |
143 | { |
144 | struct rtc_device *rtc; | |
145 | struct resource *res; | |
146 | unsigned int cen, sec; | |
ac18eb62 AN |
147 | struct rtc_plat_data *pdata; |
148 | void __iomem *ioaddr; | |
5ec3e4b7 | 149 | int ret = 0; |
87c78d95 AB |
150 | struct nvmem_config nvmem_cfg = { |
151 | .name = "ds1742_nvram", | |
87c78d95 AB |
152 | .reg_read = ds1742_nvram_read, |
153 | .reg_write = ds1742_nvram_write, | |
154 | }; | |
155 | ||
5ec3e4b7 | 156 | |
ac18eb62 | 157 | pdata = devm_kzalloc(&pdev->dev, sizeof(*pdata), GFP_KERNEL); |
5ec3e4b7 AN |
158 | if (!pdata) |
159 | return -ENOMEM; | |
25e2818e AS |
160 | |
161 | res = platform_get_resource(pdev, IORESOURCE_MEM, 0); | |
162 | ioaddr = devm_ioremap_resource(&pdev->dev, res); | |
163 | if (IS_ERR(ioaddr)) | |
164 | return PTR_ERR(ioaddr); | |
ac18eb62 | 165 | |
f9231a0c | 166 | pdata->ioaddr_nvram = ioaddr; |
87c78d95 | 167 | pdata->ioaddr_rtc = ioaddr + resource_size(res) - RTC_SIZE; |
5ec3e4b7 | 168 | |
87c78d95 AB |
169 | nvmem_cfg.size = resource_size(res) - RTC_SIZE; |
170 | nvmem_cfg.priv = pdata; | |
3a729700 | 171 | |
5ec3e4b7 | 172 | /* turn RTC on if it was not on */ |
f9231a0c | 173 | ioaddr = pdata->ioaddr_rtc; |
5ec3e4b7 AN |
174 | sec = readb(ioaddr + RTC_SECONDS); |
175 | if (sec & RTC_STOP) { | |
176 | sec &= RTC_SECONDS_MASK; | |
177 | cen = readb(ioaddr + RTC_CENTURY) & RTC_CENTURY_MASK; | |
178 | writeb(RTC_WRITE, ioaddr + RTC_CONTROL); | |
179 | writeb(sec, ioaddr + RTC_SECONDS); | |
180 | writeb(cen & RTC_CENTURY_MASK, ioaddr + RTC_CONTROL); | |
181 | } | |
391b1fe6 | 182 | if (!(readb(ioaddr + RTC_DAY) & RTC_BATT_FLAG)) |
5ec3e4b7 AN |
183 | dev_warn(&pdev->dev, "voltage-low detected.\n"); |
184 | ||
ac18eb62 AN |
185 | pdata->last_jiffies = jiffies; |
186 | platform_set_drvdata(pdev, pdata); | |
1358e7b2 AB |
187 | |
188 | rtc = devm_rtc_allocate_device(&pdev->dev); | |
ac18eb62 AN |
189 | if (IS_ERR(rtc)) |
190 | return PTR_ERR(rtc); | |
3a729700 | 191 | |
1358e7b2 AB |
192 | rtc->ops = &ds1742_rtc_ops; |
193 | ||
fdcfd854 | 194 | ret = devm_rtc_register_device(rtc); |
1358e7b2 AB |
195 | if (ret) |
196 | return ret; | |
197 | ||
6746bc09 | 198 | devm_rtc_nvmem_register(rtc, &nvmem_cfg); |
5ec3e4b7 | 199 | |
5ec3e4b7 AN |
200 | return 0; |
201 | } | |
202 | ||
9d203572 | 203 | static const struct of_device_id __maybe_unused ds1742_rtc_of_match[] = { |
663b3524 AS |
204 | { .compatible = "maxim,ds1742", }, |
205 | { } | |
206 | }; | |
207 | MODULE_DEVICE_TABLE(of, ds1742_rtc_of_match); | |
208 | ||
5ec3e4b7 AN |
209 | static struct platform_driver ds1742_rtc_driver = { |
210 | .probe = ds1742_rtc_probe, | |
5ec3e4b7 | 211 | .driver = { |
a95e23a2 | 212 | .name = "rtc-ds1742", |
3710f597 | 213 | .of_match_table = of_match_ptr(ds1742_rtc_of_match), |
5ec3e4b7 AN |
214 | }, |
215 | }; | |
216 | ||
0c4eae66 | 217 | module_platform_driver(ds1742_rtc_driver); |
5ec3e4b7 AN |
218 | |
219 | MODULE_AUTHOR("Atsushi Nemoto <anemo@mba.ocn.ne.jp>"); | |
220 | MODULE_DESCRIPTION("Dallas DS1742 RTC driver"); | |
221 | MODULE_LICENSE("GPL"); | |
ad28a07b | 222 | MODULE_ALIAS("platform:rtc-ds1742"); |