xref: /openbmc/linux/arch/powerpc/sysdev/rtc_cmos_setup.c (revision f15cbe6f1a4b4d9df59142fc8e4abb973302cf44)
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[2];
24 	int ret;
25 
26 	memset(&res, 0, sizeof(res));
27 
28 	np = of_find_compatible_node(NULL, NULL, "pnpPNP,b00");
29 	if (!np)
30 		return -ENODEV;
31 
32 	ret = of_address_to_resource(np, 0, &res[0]);
33 	of_node_put(np);
34 	if (ret)
35 		return ret;
36 
37 	/*
38 	 * RTC_PORT(x) is hardcoded in asm/mc146818rtc.h.  Verify that the
39 	 * address provided by the device node matches.
40 	 */
41 	if (res[0].start != RTC_PORT(0))
42 		return -EINVAL;
43 
44 	/* Use a fixed interrupt value of 8 since on PPC if we are using this
45 	 * its off an i8259 which we ensure has interrupt numbers 0..15. */
46 	res[1].start = 8;
47 	res[1].end = 8;
48 	res[1].flags = IORESOURCE_IRQ;
49 
50 	pd = platform_device_register_simple("rtc_cmos", -1,
51 					     &res[0], 2);
52 
53 	if (IS_ERR(pd))
54 		return PTR_ERR(pd);
55 
56 	return 0;
57 }
58 fs_initcall(add_rtc);
59 
60 MODULE_LICENSE("GPL");
61