xref: /linux/arch/powerpc/sysdev/rtc_cmos_setup.c (revision 2a6b6c9a226279b4f6668450ddb21ae655558087)
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/module.h>
16 #include <linux/mc146818rtc.h>
17 #include <linux/of_address.h>
18 
19 
20 static int  __init add_rtc(void)
21 {
22 	struct device_node *np;
23 	struct platform_device *pd;
24 	struct resource res[2];
25 	unsigned int num_res = 1;
26 	int ret;
27 
28 	memset(&res, 0, sizeof(res));
29 
30 	np = of_find_compatible_node(NULL, NULL, "pnpPNP,b00");
31 	if (!np)
32 		return -ENODEV;
33 
34 	ret = of_address_to_resource(np, 0, &res[0]);
35 	of_node_put(np);
36 	if (ret)
37 		return ret;
38 
39 	/*
40 	 * RTC_PORT(x) is hardcoded in asm/mc146818rtc.h.  Verify that the
41 	 * address provided by the device node matches.
42 	 */
43 	if (res[0].start != RTC_PORT(0))
44 		return -EINVAL;
45 
46 	np = of_find_compatible_node(NULL, NULL, "chrp,iic");
47 	if (!np)
48 		np = of_find_compatible_node(NULL, NULL, "pnpPNP,000");
49 	if (np) {
50 		of_node_put(np);
51 		/*
52 		 * Use a fixed interrupt value of 8 since on PPC if we are
53 		 * using this its off an i8259 which we ensure has interrupt
54 		 * numbers 0..15.
55 		 */
56 		res[1].start = 8;
57 		res[1].end = 8;
58 		res[1].flags = IORESOURCE_IRQ;
59 		num_res++;
60 	}
61 
62 	pd = platform_device_register_simple("rtc_cmos", -1,
63 					     &res[0], num_res);
64 
65 	return PTR_ERR_OR_ZERO(pd);
66 }
67 fs_initcall(add_rtc);
68 
69 MODULE_DESCRIPTION("PPC RTC CMOS driver");
70 MODULE_LICENSE("GPL");
71