arch/powerpc/sysdev/rtc_cmos_setup.c

   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);