arch/powerpc/sysdev/of_rtc.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  * Instantiate mmio-mapped RTC chips based on device tree information
   4  *
   5  * Copyright 2007 David Gibson <dwg@au1.ibm.com>, IBM Corporation.
   6  */
   7 #include <linux/kernel.h>
   8 #include <linux/init.h>
   9 #include <linux/of.h>
  10 #include <linux/of_address.h>
  11 #include <linux/platform_device.h>
  12 #include <linux/slab.h>
  13
  14 #include <asm/prom.h>
  15
  16 static __initdata struct {
  17         const char *compatible;
  18         char *plat_name;
  19 } of_rtc_table[] = {
  20         { "ds1743-nvram", "rtc-ds1742" },
  21 };
  22
  23 void __init of_instantiate_rtc(void)
  24 {
  25         struct device_node *node;
  26         int err;
  27         int i;
  28
  29         for (i = 0; i < ARRAY_SIZE(of_rtc_table); i++) {
  30                 char *plat_name = of_rtc_table[i].plat_name;
  31
  32                 for_each_compatible_node(node, NULL,
  33                                          of_rtc_table[i].compatible) {
  34                         struct resource *res;
  35
  36                         res = kmalloc(sizeof(*res), GFP_KERNEL);
  37                         if (!res) {
  38                                 printk(KERN_ERR "OF RTC: Out of memory "
  39                                        "allocating resource structure for %pOF\n",
  40                                        node);
  41                                 continue;
  42                         }
  43
  44                         err = of_address_to_resource(node, 0, res);
  45                         if (err) {
  46                                 printk(KERN_ERR "OF RTC: Error "
  47                                        "translating resources for %pOF\n",
  48                                        node);
  49                                 continue;
  50                         }
  51
  52                         printk(KERN_INFO "OF_RTC: %pOF is a %s @ 0x%llx-0x%llx\n",
  53                                node, plat_name,
  54                                (unsigned long long)res->start,
  55                                (unsigned long long)res->end);
  56                         platform_device_register_simple(plat_name, -1, res, 1);
  57                 }
  58         }
  59 }