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authorGeert Uytterhoeven <geert+renesas@glider.be>2019-12-11 14:52:22 +0100
committerGeert Uytterhoeven <geert+renesas@glider.be>2020-02-10 13:44:29 +0100
commit408324a3c5383716939eea8096a0f999a0665f7e (patch)
tree02700b0c6edcbc8bbf6c395deeedf71194b851e3 /arch/arm/mach-shmobile
parentbb6d3fb354c5ee8d6bde2d576eb7220ea09862b9 (diff)
downloadlinux-408324a3c5383716939eea8096a0f999a0665f7e.tar.gz
ARM: shmobile: Enable ARM_GLOBAL_TIMER on Cortex-A9 MPCore SoCs
SH-Mobile AG5 and R-Car H1 SoCs are based on the Cortex-A9 MPCore, which
includes a global timer.

Enable the ARM global timer on these SoCs, which will be used for:
  - the scheduler clock, improving scheduler accuracy from 10 ms to 3 or
    4 ns,
  - delay loops, allowing removal of calls to shmobile_init_delay() from
    the corresponding machine vectors.

Note that when using an old DTB lacking the global timer, the kernel
will still work.  However, loops-per-jiffies will no longer be preset,
and the delay loop will need to be calibrated during boot.

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Link: https://lore.kernel.org/r/20191211135222.26770-5-geert+renesas@glider.be
Diffstat (limited to 'arch/arm/mach-shmobile')
-rw-r--r--arch/arm/mach-shmobile/setup-r8a7779.c1
-rw-r--r--arch/arm/mach-shmobile/setup-sh73a0.c1
2 files changed, 0 insertions, 2 deletions
diff --git a/arch/arm/mach-shmobile/setup-r8a7779.c b/arch/arm/mach-shmobile/setup-r8a7779.c
index b13ec9088ce5..86406e3f9b22 100644
--- a/arch/arm/mach-shmobile/setup-r8a7779.c
+++ b/arch/arm/mach-shmobile/setup-r8a7779.c
@@ -72,7 +72,6 @@ static const char *const r8a7779_compat_dt[] __initconst = {
 DT_MACHINE_START(R8A7779_DT, "Generic R8A7779 (Flattened Device Tree)")
 	.smp		= smp_ops(r8a7779_smp_ops),
 	.map_io		= r8a7779_map_io,
-	.init_early	= shmobile_init_delay,
 	.init_irq	= r8a7779_init_irq_dt,
 	.init_late	= shmobile_init_late,
 	.dt_compat	= r8a7779_compat_dt,
diff --git a/arch/arm/mach-shmobile/setup-sh73a0.c b/arch/arm/mach-shmobile/setup-sh73a0.c
index cc08aa752244..eb4a62fa4289 100644
--- a/arch/arm/mach-shmobile/setup-sh73a0.c
+++ b/arch/arm/mach-shmobile/setup-sh73a0.c
@@ -56,7 +56,6 @@ static const char *const sh73a0_boards_compat_dt[] __initconst = {
 DT_MACHINE_START(SH73A0_DT, "Generic SH73A0 (Flattened Device Tree)")
 	.smp		= smp_ops(sh73a0_smp_ops),
 	.map_io		= sh73a0_map_io,
-	.init_early	= shmobile_init_delay,
 	.init_machine	= sh73a0_generic_init,
 	.init_late	= shmobile_init_late,
 	.dt_compat	= sh73a0_boards_compat_dt,