arch/mips/pic32/pic32mzda/time.c

   1 /*
   2  * Joshua Henderson <joshua.henderson@microchip.com>
   3  * Copyright (C) 2015 Microchip Technology Inc.  All rights reserved.
   4  *
   5  *  This program is free software; you can distribute it and/or modify it
   6  *  under the terms of the GNU General Public License (Version 2) as
   7  *  published by the Free Software Foundation.
   8  *
   9  *  This program is distributed in the hope it will be useful, but WITHOUT
  10  *  ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  11  *  FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  12  *  for more details.
  13  */
  14 #include <linux/clk-provider.h>
  15 #include <linux/clocksource.h>
  16 #include <linux/init.h>
  17 #include <linux/irqdomain.h>
  18 #include <linux/of.h>
  19 #include <linux/of_irq.h>
  20
  21 #include <asm/time.h>
  22
  23 #include "pic32mzda.h"
  24
  25 static const struct of_device_id pic32_infra_match[] = {
  26         { .compatible = "microchip,pic32mzda-infra", },
  27         { },
  28 };
  29
  30 #define DEFAULT_CORE_TIMER_INTERRUPT 0
  31
  32 static unsigned int pic32_xlate_core_timer_irq(void)
  33 {
  34         static struct device_node *node;
  35         unsigned int irq;
  36
  37         node = of_find_matching_node(NULL, pic32_infra_match);
  38
  39         if (WARN_ON(!node))
  40                 goto default_map;
  41
  42         irq = irq_of_parse_and_map(node, 0);
  43         if (!irq)
  44                 goto default_map;
  45
  46         return irq;
  47
  48 default_map:
  49
  50         return irq_create_mapping(NULL, DEFAULT_CORE_TIMER_INTERRUPT);
  51 }
  52
  53 unsigned int get_c0_compare_int(void)
  54 {
  55         return pic32_xlate_core_timer_irq();
  56 }
  57
  58 void __init plat_time_init(void)
  59 {
  60         unsigned long rate = pic32_get_pbclk(7);
  61
  62         of_clk_init(NULL);
  63
  64         pr_info("CPU Clock: %ldMHz\n", rate / 1000000);
  65         mips_hpt_frequency = rate / 2;
  66
  67         timer_probe();
  68 }