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537739de TB |
1 | /* |
2 | * Dallas DS1216 RTC driver | |
3 | * | |
4 | * Copyright (c) 2007 Thomas Bogendoerfer | |
5 | * | |
6 | */ | |
7 | ||
8 | #include <linux/module.h> | |
9 | #include <linux/rtc.h> | |
10 | #include <linux/platform_device.h> | |
11 | #include <linux/bcd.h> | |
12 | ||
97a1f953 | 13 | #define DRV_VERSION "0.2" |
537739de TB |
14 | |
15 | struct ds1216_regs { | |
16 | u8 tsec; | |
17 | u8 sec; | |
18 | u8 min; | |
19 | u8 hour; | |
20 | u8 wday; | |
21 | u8 mday; | |
22 | u8 month; | |
23 | u8 year; | |
24 | }; | |
25 | ||
26 | #define DS1216_HOUR_1224 (1 << 7) | |
27 | #define DS1216_HOUR_AMPM (1 << 5) | |
28 | ||
29 | struct ds1216_priv { | |
30 | struct rtc_device *rtc; | |
31 | void __iomem *ioaddr; | |
32 | size_t size; | |
33 | unsigned long baseaddr; | |
34 | }; | |
35 | ||
36 | static const u8 magic[] = { | |
37 | 0xc5, 0x3a, 0xa3, 0x5c, 0xc5, 0x3a, 0xa3, 0x5c | |
38 | }; | |
39 | ||
40 | /* | |
41 | * Read the 64 bit we'd like to have - It a series | |
42 | * of 64 bits showing up in the LSB of the base register. | |
43 | * | |
44 | */ | |
45 | static void ds1216_read(u8 __iomem *ioaddr, u8 *buf) | |
46 | { | |
47 | unsigned char c; | |
48 | int i, j; | |
49 | ||
50 | for (i = 0; i < 8; i++) { | |
51 | c = 0; | |
52 | for (j = 0; j < 8; j++) | |
53 | c |= (readb(ioaddr) & 0x1) << j; | |
54 | buf[i] = c; | |
55 | } | |
56 | } | |
57 | ||
58 | static void ds1216_write(u8 __iomem *ioaddr, const u8 *buf) | |
59 | { | |
60 | unsigned char c; | |
61 | int i, j; | |
62 | ||
63 | for (i = 0; i < 8; i++) { | |
64 | c = buf[i]; | |
65 | for (j = 0; j < 8; j++) { | |
66 | writeb(c, ioaddr); | |
67 | c = c >> 1; | |
68 | } | |
69 | } | |
70 | } | |
71 | ||
72 | static void ds1216_switch_ds_to_clock(u8 __iomem *ioaddr) | |
73 | { | |
74 | /* Reset magic pointer */ | |
75 | readb(ioaddr); | |
76 | /* Write 64 bit magic to DS1216 */ | |
77 | ds1216_write(ioaddr, magic); | |
78 | } | |
79 | ||
80 | static int ds1216_rtc_read_time(struct device *dev, struct rtc_time *tm) | |
81 | { | |
82 | struct platform_device *pdev = to_platform_device(dev); | |
83 | struct ds1216_priv *priv = platform_get_drvdata(pdev); | |
84 | struct ds1216_regs regs; | |
85 | ||
86 | ds1216_switch_ds_to_clock(priv->ioaddr); | |
87 | ds1216_read(priv->ioaddr, (u8 *)®s); | |
88 | ||
fe20ba70 AB |
89 | tm->tm_sec = bcd2bin(regs.sec); |
90 | tm->tm_min = bcd2bin(regs.min); | |
537739de TB |
91 | if (regs.hour & DS1216_HOUR_1224) { |
92 | /* AM/PM mode */ | |
fe20ba70 | 93 | tm->tm_hour = bcd2bin(regs.hour & 0x1f); |
537739de TB |
94 | if (regs.hour & DS1216_HOUR_AMPM) |
95 | tm->tm_hour += 12; | |
96 | } else | |
fe20ba70 | 97 | tm->tm_hour = bcd2bin(regs.hour & 0x3f); |
537739de | 98 | tm->tm_wday = (regs.wday & 7) - 1; |
fe20ba70 AB |
99 | tm->tm_mday = bcd2bin(regs.mday & 0x3f); |
100 | tm->tm_mon = bcd2bin(regs.month & 0x1f); | |
101 | tm->tm_year = bcd2bin(regs.year); | |
537739de TB |
102 | if (tm->tm_year < 70) |
103 | tm->tm_year += 100; | |
97a1f953 AZ |
104 | |
105 | return rtc_valid_tm(tm); | |
537739de TB |
106 | } |
107 | ||
108 | static int ds1216_rtc_set_time(struct device *dev, struct rtc_time *tm) | |
109 | { | |
110 | struct platform_device *pdev = to_platform_device(dev); | |
111 | struct ds1216_priv *priv = platform_get_drvdata(pdev); | |
112 | struct ds1216_regs regs; | |
113 | ||
114 | ds1216_switch_ds_to_clock(priv->ioaddr); | |
115 | ds1216_read(priv->ioaddr, (u8 *)®s); | |
116 | ||
117 | regs.tsec = 0; /* clear 0.1 and 0.01 seconds */ | |
fe20ba70 AB |
118 | regs.sec = bin2bcd(tm->tm_sec); |
119 | regs.min = bin2bcd(tm->tm_min); | |
537739de TB |
120 | regs.hour &= DS1216_HOUR_1224; |
121 | if (regs.hour && tm->tm_hour > 12) { | |
122 | regs.hour |= DS1216_HOUR_AMPM; | |
123 | tm->tm_hour -= 12; | |
124 | } | |
fe20ba70 | 125 | regs.hour |= bin2bcd(tm->tm_hour); |
537739de TB |
126 | regs.wday &= ~7; |
127 | regs.wday |= tm->tm_wday; | |
fe20ba70 AB |
128 | regs.mday = bin2bcd(tm->tm_mday); |
129 | regs.month = bin2bcd(tm->tm_mon); | |
130 | regs.year = bin2bcd(tm->tm_year % 100); | |
537739de TB |
131 | |
132 | ds1216_switch_ds_to_clock(priv->ioaddr); | |
133 | ds1216_write(priv->ioaddr, (u8 *)®s); | |
134 | return 0; | |
135 | } | |
136 | ||
137 | static const struct rtc_class_ops ds1216_rtc_ops = { | |
138 | .read_time = ds1216_rtc_read_time, | |
139 | .set_time = ds1216_rtc_set_time, | |
140 | }; | |
141 | ||
97a1f953 | 142 | static int __init ds1216_rtc_probe(struct platform_device *pdev) |
537739de | 143 | { |
537739de TB |
144 | struct resource *res; |
145 | struct ds1216_priv *priv; | |
146 | int ret = 0; | |
147 | u8 dummy[8]; | |
148 | ||
149 | res = platform_get_resource(pdev, IORESOURCE_MEM, 0); | |
150 | if (!res) | |
151 | return -ENODEV; | |
152 | priv = kzalloc(sizeof *priv, GFP_KERNEL); | |
153 | if (!priv) | |
154 | return -ENOMEM; | |
97a1f953 AZ |
155 | |
156 | platform_set_drvdata(pdev, priv); | |
157 | ||
158 | priv->size = resource_size(res); | |
537739de TB |
159 | if (!request_mem_region(res->start, priv->size, pdev->name)) { |
160 | ret = -EBUSY; | |
161 | goto out; | |
162 | } | |
163 | priv->baseaddr = res->start; | |
164 | priv->ioaddr = ioremap(priv->baseaddr, priv->size); | |
165 | if (!priv->ioaddr) { | |
166 | ret = -ENOMEM; | |
167 | goto out; | |
168 | } | |
97a1f953 | 169 | priv->rtc = rtc_device_register("ds1216", &pdev->dev, |
537739de | 170 | &ds1216_rtc_ops, THIS_MODULE); |
97a1f953 AZ |
171 | if (IS_ERR(priv->rtc)) { |
172 | ret = PTR_ERR(priv->rtc); | |
537739de TB |
173 | goto out; |
174 | } | |
537739de TB |
175 | |
176 | /* dummy read to get clock into a known state */ | |
177 | ds1216_read(priv->ioaddr, dummy); | |
178 | return 0; | |
179 | ||
180 | out: | |
537739de TB |
181 | if (priv->ioaddr) |
182 | iounmap(priv->ioaddr); | |
183 | if (priv->baseaddr) | |
184 | release_mem_region(priv->baseaddr, priv->size); | |
185 | kfree(priv); | |
186 | return ret; | |
187 | } | |
188 | ||
97a1f953 | 189 | static int __exit ds1216_rtc_remove(struct platform_device *pdev) |
537739de TB |
190 | { |
191 | struct ds1216_priv *priv = platform_get_drvdata(pdev); | |
192 | ||
193 | rtc_device_unregister(priv->rtc); | |
194 | iounmap(priv->ioaddr); | |
195 | release_mem_region(priv->baseaddr, priv->size); | |
196 | kfree(priv); | |
197 | return 0; | |
198 | } | |
199 | ||
200 | static struct platform_driver ds1216_rtc_platform_driver = { | |
201 | .driver = { | |
202 | .name = "rtc-ds1216", | |
203 | .owner = THIS_MODULE, | |
204 | }, | |
97a1f953 | 205 | .remove = __exit_p(ds1216_rtc_remove), |
537739de TB |
206 | }; |
207 | ||
208 | static int __init ds1216_rtc_init(void) | |
209 | { | |
97a1f953 | 210 | return platform_driver_probe(&ds1216_rtc_platform_driver, ds1216_rtc_probe); |
537739de TB |
211 | } |
212 | ||
213 | static void __exit ds1216_rtc_exit(void) | |
214 | { | |
215 | platform_driver_unregister(&ds1216_rtc_platform_driver); | |
216 | } | |
217 | ||
218 | MODULE_AUTHOR("Thomas Bogendoerfer <tsbogend@alpha.franken.de>"); | |
219 | MODULE_DESCRIPTION("DS1216 RTC driver"); | |
220 | MODULE_LICENSE("GPL"); | |
221 | MODULE_VERSION(DRV_VERSION); | |
ad28a07b | 222 | MODULE_ALIAS("platform:rtc-ds1216"); |
537739de TB |
223 | |
224 | module_init(ds1216_rtc_init); | |
225 | module_exit(ds1216_rtc_exit); |