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ARM: shmobile: rcar-gen2: Add CA7 arch_timer initialization for r8a7794

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On E2, the arch timer is hooked up to a different clock, and the CA7's arch
timer CNTVOFF register must be initialized.

Based on work by Hisashi Nakamura.

Signed-off-by: Ulrich Hecht <ulrich.hecht+renesas@gmail.com>
Signed-off-by: Simon Horman <horms+renesas@verge.net.au>
This commit is contained in:
Ulrich Hecht 2014-09-12 10:52:05 +02:00 committed by Simon Horman
parent 27c1bb20d4
commit 9ce3fa6816
1 changed files with 48 additions and 22 deletions
repo.diff.show_diff_stats Download patch file Download diff file Expand all files Collapse all files

70
arch/arm/mach-shmobile/setup-rcar-gen2.c
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@ -3,6 +3,7 @@
*
* Copyright (C) 2013 Renesas Solutions Corp.
* Copyright (C) 2013 Magnus Damm
* Copyright (C) 2014 Ulrich Hecht
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
@ -24,6 +25,7 @@
#include <linux/dma-contiguous.h>
#include <linux/io.h>
#include <linux/kernel.h>
#include <linux/of.h>
#include <linux/of_fdt.h>
#include <asm/mach/arch.h>
#include "common.h"
@ -54,37 +56,61 @@ void __init rcar_gen2_timer_init(void)
{
#if defined(CONFIG_ARM_ARCH_TIMER) || defined(CONFIG_COMMON_CLK)
u32 mode = rcar_gen2_read_mode_pins();
bool is_e2 = (bool)of_find_compatible_node(NULL, NULL,
"renesas,r8a7794");
#endif
#ifdef CONFIG_ARM_ARCH_TIMER
void __iomem *base;
int extal_mhz = 0;
u32 freq;
/* At Linux boot time the r8a7790 arch timer comes up
* with the counter disabled. Moreover, it may also report
* a potentially incorrect fixed 13 MHz frequency. To be
* correct these registers need to be updated to use the
* frequency EXTAL / 2 which can be determined by the MD pins.
*/
if (is_e2) {
freq = 260000000 / 8; /* ZS / 8 */
/* CNTVOFF has to be initialized either from non-secure
* Hypervisor mode or secure Monitor mode with SCR.NS==1.
* If TrustZone is enabled then it should be handled by the
* secure code.
*/
asm volatile(
" cps 0x16\n"
" mrc p15, 0, r1, c1, c1, 0\n"
" orr r0, r1, #1\n"
" mcr p15, 0, r0, c1, c1, 0\n"
" isb\n"
" mov r0, #0\n"
" mcrr p15, 4, r0, r0, c14\n"
" isb\n"
" mcr p15, 0, r1, c1, c1, 0\n"
" isb\n"
" cps 0x13\n"
: : : "r0", "r1");
} else {
/* At Linux boot time the r8a7790 arch timer comes up
* with the counter disabled. Moreover, it may also report
* a potentially incorrect fixed 13 MHz frequency. To be
* correct these registers need to be updated to use the
* frequency EXTAL / 2 which can be determined by the MD pins.
*/
switch (mode & (MD(14) | MD(13))) {
case 0:
extal_mhz = 15;
break;
case MD(13):
extal_mhz = 20;
break;
case MD(14):
extal_mhz = 26;
break;
case MD(13) | MD(14):
extal_mhz = 30;
break;
switch (mode & (MD(14) | MD(13))) {
case 0:
extal_mhz = 15;
break;
case MD(13):
extal_mhz = 20;
break;
case MD(14):
extal_mhz = 26;
break;
case MD(13) | MD(14):
extal_mhz = 30;
break;
}
/* The arch timer frequency equals EXTAL / 2 */
freq = extal_mhz * (1000000 / 2);
}
/* The arch timer frequency equals EXTAL / 2 */
freq = extal_mhz * (1000000 / 2);
/* Remap "armgcnt address map" space */
base = ioremap(0xe6080000, PAGE_SIZE);