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
20static 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, compat: "pnpPNP,b00");
31 if (!np)
32 return -ENODEV;
33
34 ret = of_address_to_resource(dev: np, index: 0, r: &res[0]);
35 of_node_put(node: 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, compat: "chrp,iic");
47 if (!np)
48 np = of_find_compatible_node(NULL, NULL, compat: "pnpPNP,000");
49 if (np) {
50 of_node_put(node: 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(name: "rtc_cmos", id: -1,
63 res: &res[0], num: num_res);
64
65 return PTR_ERR_OR_ZERO(ptr: pd);
66}
67fs_initcall(add_rtc);
68
69MODULE_LICENSE("GPL");
70

source code of linux/arch/powerpc/sysdev/rtc_cmos_setup.c