]>
Commit | Line | Data |
---|---|---|
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 | ||
13 | #define DRV_VERSION "0.1" | |
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 | ||
89 | tm->tm_sec = BCD2BIN(regs.sec); | |
90 | tm->tm_min = BCD2BIN(regs.min); | |
91 | if (regs.hour & DS1216_HOUR_1224) { | |
92 | /* AM/PM mode */ | |
93 | tm->tm_hour = BCD2BIN(regs.hour & 0x1f); | |
94 | if (regs.hour & DS1216_HOUR_AMPM) | |
95 | tm->tm_hour += 12; | |
96 | } else | |
97 | tm->tm_hour = BCD2BIN(regs.hour & 0x3f); | |
98 | tm->tm_wday = (regs.wday & 7) - 1; | |
99 | tm->tm_mday = BCD2BIN(regs.mday & 0x3f); | |
100 | tm->tm_mon = BCD2BIN(regs.month & 0x1f); | |
101 | tm->tm_year = BCD2BIN(regs.year); | |
102 | if (tm->tm_year < 70) | |
103 | tm->tm_year += 100; | |
104 | return 0; | |
105 | } | |
106 | ||
107 | static int ds1216_rtc_set_time(struct device *dev, struct rtc_time *tm) | |
108 | { | |
109 | struct platform_device *pdev = to_platform_device(dev); | |
110 | struct ds1216_priv *priv = platform_get_drvdata(pdev); | |
111 | struct ds1216_regs regs; | |
112 | ||
113 | ds1216_switch_ds_to_clock(priv->ioaddr); | |
114 | ds1216_read(priv->ioaddr, (u8 *)®s); | |
115 | ||
116 | regs.tsec = 0; /* clear 0.1 and 0.01 seconds */ | |
117 | regs.sec = BIN2BCD(tm->tm_sec); | |
118 | regs.min = BIN2BCD(tm->tm_min); | |
119 | regs.hour &= DS1216_HOUR_1224; | |
120 | if (regs.hour && tm->tm_hour > 12) { | |
121 | regs.hour |= DS1216_HOUR_AMPM; | |
122 | tm->tm_hour -= 12; | |
123 | } | |
124 | regs.hour |= BIN2BCD(tm->tm_hour); | |
125 | regs.wday &= ~7; | |
126 | regs.wday |= tm->tm_wday; | |
127 | regs.mday = BIN2BCD(tm->tm_mday); | |
128 | regs.month = BIN2BCD(tm->tm_mon); | |
129 | regs.year = BIN2BCD(tm->tm_year % 100); | |
130 | ||
131 | ds1216_switch_ds_to_clock(priv->ioaddr); | |
132 | ds1216_write(priv->ioaddr, (u8 *)®s); | |
133 | return 0; | |
134 | } | |
135 | ||
136 | static const struct rtc_class_ops ds1216_rtc_ops = { | |
137 | .read_time = ds1216_rtc_read_time, | |
138 | .set_time = ds1216_rtc_set_time, | |
139 | }; | |
140 | ||
141 | static int __devinit ds1216_rtc_probe(struct platform_device *pdev) | |
142 | { | |
143 | struct rtc_device *rtc; | |
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; | |
155 | priv->size = res->end - res->start + 1; | |
156 | if (!request_mem_region(res->start, priv->size, pdev->name)) { | |
157 | ret = -EBUSY; | |
158 | goto out; | |
159 | } | |
160 | priv->baseaddr = res->start; | |
161 | priv->ioaddr = ioremap(priv->baseaddr, priv->size); | |
162 | if (!priv->ioaddr) { | |
163 | ret = -ENOMEM; | |
164 | goto out; | |
165 | } | |
166 | rtc = rtc_device_register("ds1216", &pdev->dev, | |
167 | &ds1216_rtc_ops, THIS_MODULE); | |
168 | if (IS_ERR(rtc)) { | |
169 | ret = PTR_ERR(rtc); | |
170 | goto out; | |
171 | } | |
172 | priv->rtc = rtc; | |
173 | platform_set_drvdata(pdev, priv); | |
174 | ||
175 | /* dummy read to get clock into a known state */ | |
176 | ds1216_read(priv->ioaddr, dummy); | |
177 | return 0; | |
178 | ||
179 | out: | |
180 | if (priv->rtc) | |
181 | rtc_device_unregister(priv->rtc); | |
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 | ||
190 | static int __devexit ds1216_rtc_remove(struct platform_device *pdev) | |
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 | }, | |
206 | .probe = ds1216_rtc_probe, | |
207 | .remove = __devexit_p(ds1216_rtc_remove), | |
208 | }; | |
209 | ||
210 | static int __init ds1216_rtc_init(void) | |
211 | { | |
212 | return platform_driver_register(&ds1216_rtc_platform_driver); | |
213 | } | |
214 | ||
215 | static void __exit ds1216_rtc_exit(void) | |
216 | { | |
217 | platform_driver_unregister(&ds1216_rtc_platform_driver); | |
218 | } | |
219 | ||
220 | MODULE_AUTHOR("Thomas Bogendoerfer <tsbogend@alpha.franken.de>"); | |
221 | MODULE_DESCRIPTION("DS1216 RTC driver"); | |
222 | MODULE_LICENSE("GPL"); | |
223 | MODULE_VERSION(DRV_VERSION); | |
224 | ||
225 | module_init(ds1216_rtc_init); | |
226 | module_exit(ds1216_rtc_exit); |