The check for R-Car E2 (which was later extended to R-Car V2H), served
two purposes:
1. Use the correct parent clock for the arch timer,
2. Initialize the arch timer.
However, the second part shouldn't be done on V2H, as it only applies to
Cortex-A7 CPU cores, while V2H has a dual Cortex-A15.
Hence split off the arch timer initialization, and make it run on
Cortex-A7 only.
While at it, add some documentation to the inline asm.
Fixes: 2477a356dd245bbb ("ARM: shmobile: rcar-gen2: Correct arch timer frequency on R-Car V2H")
Signed-off-by: Geert Uytterhoeven <geert+renesas@xxxxxxxxx>
---
arch/arm/mach-shmobile/setup-rcar-gen2.c | 21 +++++++++++++--------
1 file changed, 13 insertions(+), 8 deletions(-)
diff --git a/arch/arm/mach-shmobile/setup-rcar-gen2.c b/arch/arm/mach-shmobile/setup-rcar-gen2.c
index 52d466b759730d74..caa866d406e50795 100644
--- a/arch/arm/mach-shmobile/setup-rcar-gen2.c
+++ b/arch/arm/mach-shmobile/setup-rcar-gen2.c
@@ -26,6 +26,7 @@
#include <linux/of_fdt.h>
#include <linux/of_platform.h>
#include <asm/mach/arch.h>
+#include <asm/cputype.h>
#include "common.h"
#include "rcar-gen2.h"
@@ -58,27 +59,31 @@ void __init rcar_gen2_timer_init(void)
void __iomem *base;
u32 freq;
- if (of_machine_is_compatible("renesas,r8a7792") ||
- of_machine_is_compatible("renesas,r8a7794")) {
- freq = 260000000 / 8; /* ZS / 8 */
- /* CNTVOFF has to be initialized either from non-secure
+ if (read_cpuid_part() == ARM_CPU_PART_CORTEX_A7) {
+ /*
+ * 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"
+ " mrc p15, 0, r1, c1, c1, 0\n" /* Get Secure Config */
" orr r0, r1, #1\n"
- " mcr p15, 0, r0, c1, c1, 0\n"
+ " mcr p15, 0, r0, c1, c1, 0\n" /* Set Non Secure bit */
" isb\n"
" mov r0, #0\n"
- " mcrr p15, 4, r0, r0, c14\n"
+ " mcrr p15, 4, r0, r0, c14\n" /* CNTVOFF = 0 */
" isb\n"
- " mcr p15, 0, r1, c1, c1, 0\n"
+ " mcr p15, 0, r1, c1, c1, 0\n" /* Set Secure bit */
" isb\n"
" cps 0x13\n"
: : : "r0", "r1");
+ }
+
+ if (of_machine_is_compatible("renesas,r8a7792") ||
+ of_machine_is_compatible("renesas,r8a7794")) {
+ freq = 260000000 / 8; /* ZS / 8 */
} else {
/* At Linux boot time the r8a7790 arch timer comes up
* with the counter disabled. Moreover, it may also report
--
2.7.4
