1 /*
2  * Setup code for PC-style Real-Time Clock.
3  *
4  * Author: Wade Farnsworth <wfarnsworth@mvista.com>
5  *
6  * 2007 (c) MontaVista Software, Inc. This file is licensed under
7  * the terms of the GNU General Public License version 2. This program
8  * is licensed "as is" without any warranty of any kind, whether express
9  * or implied.
10  */
11 
12 #include <linux/platform_device.h>
13 #include <linux/err.h>
14 #include <linux/init.h>
15 #include <linux/mc146818rtc.h>
16 
17 #include <asm/prom.h>
18 
19 static int  __init add_rtc(void)
20 {
21 	struct device_node *np;
22 	struct platform_device *pd;
23 	struct resource res;
24 	int ret;
25 
26 	np = of_find_compatible_node(NULL, NULL, "pnpPNP,b00");
27 	if (!np)
28 		return -ENODEV;
29 
30 	ret = of_address_to_resource(np, 0, &res);
31 	of_node_put(np);
32 	if (ret)
33 		return ret;
34 
35 	/*
36 	 * RTC_PORT(x) is hardcoded in asm/mc146818rtc.h.  Verify that the
37 	 * address provided by the device node matches.
38 	 */
39 	if (res.start != RTC_PORT(0))
40 		return -EINVAL;
41 
42 	pd = platform_device_register_simple("rtc_cmos", -1,
43 					     &res, 1);
44 	if (IS_ERR(pd))
45 		return PTR_ERR(pd);
46 
47 	return 0;
48 }
49 fs_initcall(add_rtc);
50