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

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>

diff --git a/arch/arm/mach-shmobile/setup-rcar-gen2.c b/arch/arm/mach-shmobile/setup-rcar-gen2.c
index 42d5b43..7ed9279 100644 (file)
--- a/arch/arm/mach-shmobile/setup-rcar-gen2.c
+++ b/arch/arm/mach-shmobile/setup-rcar-gen2.c
@@ -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.
-        */
-
-       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;
+       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;
+               }
+
+               /* 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);