arch/mips/kernel/csrc-bcm1480.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  * Copyright (C) 2000,2001,2004 Broadcom Corporation
   4  */
   5 #include <linux/clocksource.h>
   6 #include <linux/sched_clock.h>
   7
   8 #include <asm/addrspace.h>
   9 #include <asm/io.h>
  10 #include <asm/time.h>
  11
  12 #include <asm/sibyte/bcm1480_regs.h>
  13 #include <asm/sibyte/sb1250_regs.h>
  14 #include <asm/sibyte/bcm1480_int.h>
  15 #include <asm/sibyte/bcm1480_scd.h>
  16
  17 #include <asm/sibyte/sb1250.h>
  18
  19 static u64 bcm1480_hpt_read(struct clocksource *cs)
  20 {
  21         return (u64) __raw_readq(IOADDR(A_SCD_ZBBUS_CYCLE_COUNT));
  22 }
  23
  24 struct clocksource bcm1480_clocksource = {
  25         .name   = "zbbus-cycles",
  26         .rating = 200,
  27         .read   = bcm1480_hpt_read,
  28         .mask   = CLOCKSOURCE_MASK(64),
  29         .flags  = CLOCK_SOURCE_IS_CONTINUOUS,
  30 };
  31
  32 static u64 notrace sb1480_read_sched_clock(void)
  33 {
  34         return __raw_readq(IOADDR(A_SCD_ZBBUS_CYCLE_COUNT));
  35 }
  36
  37 void __init sb1480_clocksource_init(void)
  38 {
  39         struct clocksource *cs = &bcm1480_clocksource;
  40         unsigned int plldiv;
  41         unsigned long zbbus;
  42
  43         plldiv = G_BCM1480_SYS_PLL_DIV(__raw_readq(IOADDR(A_SCD_SYSTEM_CFG)));
  44         zbbus = ((plldiv >> 1) * 50000000) + ((plldiv & 1) * 25000000);
  45         clocksource_register_hz(cs, zbbus);
  46
  47         sched_clock_register(sb1480_read_sched_clock, 64, zbbus);
  48 }