Commit | Line | Data |
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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> | |
5a0e3ad6 | 12 | #include <linux/slab.h> |
537739de | 13 | |
97a1f953 | 14 | #define DRV_VERSION "0.2" |
537739de TB |
15 | |
16 | struct ds1216_regs { | |
17 | u8 tsec; | |
18 | u8 sec; | |
19 | u8 min; | |
20 | u8 hour; | |
21 | u8 wday; | |
22 | u8 mday; | |
23 | u8 month; | |
24 | u8 year; | |
25 | }; | |
26 | ||
27 | #define DS1216_HOUR_1224 (1 << 7) | |
28 | #define DS1216_HOUR_AMPM (1 << 5) | |
29 | ||
30 | struct ds1216_priv { | |
31 | struct rtc_device *rtc; | |
32 | void __iomem *ioaddr; | |
33 | size_t size; | |
34 | unsigned long baseaddr; | |
35 | }; | |
36 | ||
37 | static const u8 magic[] = { | |
38 | 0xc5, 0x3a, 0xa3, 0x5c, 0xc5, 0x3a, 0xa3, 0x5c | |
39 | }; | |
40 | ||
41 | /* | |
42 | * Read the 64 bit we'd like to have - It a series | |
43 | * of 64 bits showing up in the LSB of the base register. | |
44 | * | |
45 | */ | |
46 | static void ds1216_read(u8 __iomem *ioaddr, u8 *buf) | |
47 | { | |
48 | unsigned char c; | |
49 | int i, j; | |
50 | ||
51 | for (i = 0; i < 8; i++) { | |
52 | c = 0; | |
53 | for (j = 0; j < 8; j++) | |
54 | c |= (readb(ioaddr) & 0x1) << j; | |
55 | buf[i] = c; | |
56 | } | |
57 | } | |
58 | ||
59 | static void ds1216_write(u8 __iomem *ioaddr, const u8 *buf) | |
60 | { | |
61 | unsigned char c; | |
62 | int i, j; | |
63 | ||
64 | for (i = 0; i < 8; i++) { | |
65 | c = buf[i]; | |
66 | for (j = 0; j < 8; j++) { | |
67 | writeb(c, ioaddr); | |
68 | c = c >> 1; | |
69 | } | |
70 | } | |
71 | } | |
72 | ||
73 | static void ds1216_switch_ds_to_clock(u8 __iomem *ioaddr) | |
74 | { | |
75 | /* Reset magic pointer */ | |
76 | readb(ioaddr); | |
77 | /* Write 64 bit magic to DS1216 */ | |
78 | ds1216_write(ioaddr, magic); | |
79 | } | |
80 | ||
81 | static int ds1216_rtc_read_time(struct device *dev, struct rtc_time *tm) | |
82 | { | |
83 | struct platform_device *pdev = to_platform_device(dev); | |
84 | struct ds1216_priv *priv = platform_get_drvdata(pdev); | |
85 | struct ds1216_regs regs; | |
86 | ||
87 | ds1216_switch_ds_to_clock(priv->ioaddr); | |
88 | ds1216_read(priv->ioaddr, (u8 *)®s); | |
89 | ||
fe20ba70 AB |
90 | tm->tm_sec = bcd2bin(regs.sec); |
91 | tm->tm_min = bcd2bin(regs.min); | |
537739de TB |
92 | if (regs.hour & DS1216_HOUR_1224) { |
93 | /* AM/PM mode */ | |
fe20ba70 | 94 | tm->tm_hour = bcd2bin(regs.hour & 0x1f); |
537739de TB |
95 | if (regs.hour & DS1216_HOUR_AMPM) |
96 | tm->tm_hour += 12; | |
97 | } else | |
fe20ba70 | 98 | tm->tm_hour = bcd2bin(regs.hour & 0x3f); |
537739de | 99 | tm->tm_wday = (regs.wday & 7) - 1; |
fe20ba70 AB |
100 | tm->tm_mday = bcd2bin(regs.mday & 0x3f); |
101 | tm->tm_mon = bcd2bin(regs.month & 0x1f); | |
102 | tm->tm_year = bcd2bin(regs.year); | |
537739de TB |
103 | if (tm->tm_year < 70) |
104 | tm->tm_year += 100; | |
97a1f953 AZ |
105 | |
106 | return rtc_valid_tm(tm); | |
537739de TB |
107 | } |
108 | ||
109 | static int ds1216_rtc_set_time(struct device *dev, struct rtc_time *tm) | |
110 | { | |
111 | struct platform_device *pdev = to_platform_device(dev); | |
112 | struct ds1216_priv *priv = platform_get_drvdata(pdev); | |
113 | struct ds1216_regs regs; | |
114 | ||
115 | ds1216_switch_ds_to_clock(priv->ioaddr); | |
116 | ds1216_read(priv->ioaddr, (u8 *)®s); | |
117 | ||
118 | regs.tsec = 0; /* clear 0.1 and 0.01 seconds */ | |
fe20ba70 AB |
119 | regs.sec = bin2bcd(tm->tm_sec); |
120 | regs.min = bin2bcd(tm->tm_min); | |
537739de TB |
121 | regs.hour &= DS1216_HOUR_1224; |
122 | if (regs.hour && tm->tm_hour > 12) { | |
123 | regs.hour |= DS1216_HOUR_AMPM; | |
124 | tm->tm_hour -= 12; | |
125 | } | |
fe20ba70 | 126 | regs.hour |= bin2bcd(tm->tm_hour); |
537739de TB |
127 | regs.wday &= ~7; |
128 | regs.wday |= tm->tm_wday; | |
fe20ba70 AB |
129 | regs.mday = bin2bcd(tm->tm_mday); |
130 | regs.month = bin2bcd(tm->tm_mon); | |
131 | regs.year = bin2bcd(tm->tm_year % 100); | |
537739de TB |
132 | |
133 | ds1216_switch_ds_to_clock(priv->ioaddr); | |
134 | ds1216_write(priv->ioaddr, (u8 *)®s); | |
135 | return 0; | |
136 | } | |
137 | ||
138 | static const struct rtc_class_ops ds1216_rtc_ops = { | |
139 | .read_time = ds1216_rtc_read_time, | |
140 | .set_time = ds1216_rtc_set_time, | |
141 | }; | |
142 | ||
97a1f953 | 143 | static int __init ds1216_rtc_probe(struct platform_device *pdev) |
537739de | 144 | { |
537739de TB |
145 | struct resource *res; |
146 | struct ds1216_priv *priv; | |
147 | int ret = 0; | |
148 | u8 dummy[8]; | |
149 | ||
150 | res = platform_get_resource(pdev, IORESOURCE_MEM, 0); | |
151 | if (!res) | |
152 | return -ENODEV; | |
153 | priv = kzalloc(sizeof *priv, GFP_KERNEL); | |
154 | if (!priv) | |
155 | return -ENOMEM; | |
97a1f953 AZ |
156 | |
157 | platform_set_drvdata(pdev, priv); | |
158 | ||
159 | priv->size = resource_size(res); | |
537739de TB |
160 | if (!request_mem_region(res->start, priv->size, pdev->name)) { |
161 | ret = -EBUSY; | |
162 | goto out; | |
163 | } | |
164 | priv->baseaddr = res->start; | |
165 | priv->ioaddr = ioremap(priv->baseaddr, priv->size); | |
166 | if (!priv->ioaddr) { | |
167 | ret = -ENOMEM; | |
168 | goto out; | |
169 | } | |
97a1f953 | 170 | priv->rtc = rtc_device_register("ds1216", &pdev->dev, |
537739de | 171 | &ds1216_rtc_ops, THIS_MODULE); |
97a1f953 AZ |
172 | if (IS_ERR(priv->rtc)) { |
173 | ret = PTR_ERR(priv->rtc); | |
537739de TB |
174 | goto out; |
175 | } | |
537739de TB |
176 | |
177 | /* dummy read to get clock into a known state */ | |
178 | ds1216_read(priv->ioaddr, dummy); | |
179 | return 0; | |
180 | ||
181 | out: | |
537739de TB |
182 | if (priv->ioaddr) |
183 | iounmap(priv->ioaddr); | |
184 | if (priv->baseaddr) | |
185 | release_mem_region(priv->baseaddr, priv->size); | |
186 | kfree(priv); | |
187 | return ret; | |
188 | } | |
189 | ||
97a1f953 | 190 | static int __exit ds1216_rtc_remove(struct platform_device *pdev) |
537739de TB |
191 | { |
192 | struct ds1216_priv *priv = platform_get_drvdata(pdev); | |
193 | ||
194 | rtc_device_unregister(priv->rtc); | |
195 | iounmap(priv->ioaddr); | |
196 | release_mem_region(priv->baseaddr, priv->size); | |
197 | kfree(priv); | |
198 | return 0; | |
199 | } | |
200 | ||
201 | static struct platform_driver ds1216_rtc_platform_driver = { | |
202 | .driver = { | |
203 | .name = "rtc-ds1216", | |
204 | .owner = THIS_MODULE, | |
205 | }, | |
97a1f953 | 206 | .remove = __exit_p(ds1216_rtc_remove), |
537739de TB |
207 | }; |
208 | ||
209 | static int __init ds1216_rtc_init(void) | |
210 | { | |
97a1f953 | 211 | return platform_driver_probe(&ds1216_rtc_platform_driver, ds1216_rtc_probe); |
537739de TB |
212 | } |
213 | ||
214 | static void __exit ds1216_rtc_exit(void) | |
215 | { | |
216 | platform_driver_unregister(&ds1216_rtc_platform_driver); | |
217 | } | |
218 | ||
219 | MODULE_AUTHOR("Thomas Bogendoerfer <tsbogend@alpha.franken.de>"); | |
220 | MODULE_DESCRIPTION("DS1216 RTC driver"); | |
221 | MODULE_LICENSE("GPL"); | |
222 | MODULE_VERSION(DRV_VERSION); | |
ad28a07b | 223 | MODULE_ALIAS("platform:rtc-ds1216"); |
537739de TB |
224 | |
225 | module_init(ds1216_rtc_init); | |
226 | module_exit(ds1216_rtc_exit); |