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/module.h>
  16 #include <linux/mc146818rtc.h>
  17
  18 #include <asm/prom.h>
  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_LICENSE("GPL");