rtc_cmos_setup.c

Go to the documentation of this file.

/*
 * Setup code for PC-style Real-Time Clock.
 *
 * Author: Wade Farnsworth <[email protected]>
 *
 * 2007 (c) MontaVista Software, Inc. This file is licensed under
 * the terms of the GNU General Public License version 2. This program
 * is licensed "as is" without any warranty of any kind, whether express
 * or implied.
 */

#include <linux/platform_device.h>
#include <linux/err.h>
#include <linux/init.h>
#include <linux/module.h>
#include <linux/mc146818rtc.h>

#include <asm/prom.h>

static int  __init add_rtc(void)
{
    struct device_node *np;
    struct platform_device *pd;
    struct resource res[2];
    unsigned int num_res = 1;
    int ret;

    memset(&res, 0, sizeof(res));

    np = of_find_compatible_node(NULL, NULL, "pnpPNP,b00");
    if (!np)
        return -ENODEV;

    ret = of_address_to_resource(np, 0, &res[0]);
    of_node_put(np);
    if (ret)
        return ret;

    /*
     * RTC_PORT(x) is hardcoded in asm/mc146818rtc.h.  Verify that the
     * address provided by the device node matches.
     */
    if (res[0].start != RTC_PORT(0))
        return -EINVAL;

    np = of_find_compatible_node(NULL, NULL, "chrp,iic");
    if (!np)
        np = of_find_compatible_node(NULL, NULL, "pnpPNP,000");
    if (np) {
        of_node_put(np);
        /*
         * Use a fixed interrupt value of 8 since on PPC if we are
         * using this its off an i8259 which we ensure has interrupt
         * numbers 0..15.
         */
        res[1].start = 8;
        res[1].end = 8;
        res[1].flags = IORESOURCE_IRQ;
        num_res++;
    }

    pd = platform_device_register_simple("rtc_cmos", -1,
                         &res[0], num_res);

    if (IS_ERR(pd))
        return PTR_ERR(pd);

    return 0;
}
fs_initcall(add_rtc);

MODULE_LICENSE("GPL");