xref: /openbmc/linux/arch/powerpc/sysdev/rtc_cmos_setup.c (revision df2634f43f5106947f3735a0b61a6527a4b278cd)
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 	unsigned int num_res = 1;
25 	int ret;
26 
27 	memset(&res, 0, sizeof(res));
28 
29 	np = of_find_compatible_node(NULL, NULL, "pnpPNP,b00");
30 	if (!np)
31 		return -ENODEV;
32 
33 	ret = of_address_to_resource(np, 0, &res[0]);
34 	of_node_put(np);
35 	if (ret)
36 		return ret;
37 
38 	/*
39 	 * RTC_PORT(x) is hardcoded in asm/mc146818rtc.h.  Verify that the
40 	 * address provided by the device node matches.
41 	 */
42 	if (res[0].start != RTC_PORT(0))
43 		return -EINVAL;
44 
45 	np = of_find_compatible_node(NULL, NULL, "chrp,iic");
46 	if (!np)
47 		np = of_find_compatible_node(NULL, NULL, "pnpPNP,000");
48 	if (np) {
49 		of_node_put(np);
50 		/*
51 		 * Use a fixed interrupt value of 8 since on PPC if we are
52 		 * using this its off an i8259 which we ensure has interrupt
53 		 * numbers 0..15.
54 		 */
55 		res[1].start = 8;
56 		res[1].end = 8;
57 		res[1].flags = IORESOURCE_IRQ;
58 		num_res++;
59 	}
60 
61 	pd = platform_device_register_simple("rtc_cmos", -1,
62 					     &res[0], num_res);
63 
64 	if (IS_ERR(pd))
65 		return PTR_ERR(pd);
66 
67 	return 0;
68 }
69 fs_initcall(add_rtc);
70 
71 MODULE_LICENSE("GPL");
72