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

1 files changed, 2 insertions, 0 deletions

diff --git a/drivers/soc/renesas/Kconfig b/drivers/soc/renesas/Kconfig
index ba2b8b51d2d9..de5cfe3fddd3 100644
--- a/drivers/soc/renesas/Kconfig
+++ b/drivers/soc/renesas/Kconfig
@@ -116,6 +116,7 @@ config ARCH_R8A7779
 	bool "R-Car H1 (R8A77790)"
 	select ARCH_RCAR_GEN1
 	select ARM_ERRATA_754322
+	select ARM_GLOBAL_TIMER
 	select HAVE_ARM_SCU if SMP
 	select HAVE_ARM_TWD if SMP
 	select SYSC_R8A7779
@@ -163,6 +164,7 @@ config ARCH_SH73A0
 	bool "SH-Mobile AG5 (R8A73A00)"
 	select ARCH_RMOBILE
 	select ARM_ERRATA_754322
+	select ARM_GLOBAL_TIMER
 	select HAVE_ARM_SCU if SMP
 	select HAVE_ARM_TWD if SMP
 	select RENESAS_INTC_IRQPIN