g***@uclinux.org
2014-05-27 06:28:20 UTC
From: Greg Ungerer <***@uclinux.org>
The timer code used on the ColdFire 53xx series is abusing the old 16bit
timer code. The hardware module it uses is really the more modern DMA
timer hardware module. It bends the reads/writes and modifies some addresses
so that it basically works.
It would be much better to use the modern Programmable Interrupt Timer
hardware module that these SoC contain. This PIT timer is used on all
the other modern ColdFire family members.
We also have DMA timer code that we will in the future use as a more
accurate clock source and cycle counter. So the idea here is to clean up
this usage to free up the timer hardware.
I don't have any 53xx based hardware, so I have not been able to run time
test this. If anyone can test this and confirm that it works as expected
that would be great.
Signed-off-by: Greg Ungerer <***@uclinux.org>
---
arch/m68k/Kconfig.cpu | 2 ++
arch/m68k/include/asm/m53xxsim.h | 19 ++++++++++---------
arch/m68k/include/asm/mcftimer.h | 4 ----
arch/m68k/platform/coldfire/Makefile | 2 +-
arch/m68k/platform/coldfire/timers.c | 16 ++--------------
5 files changed, 15 insertions(+), 28 deletions(-)
The timer code used on the ColdFire 53xx series is abusing the old 16bit
timer code. The hardware module it uses is really the more modern DMA
timer hardware module. It bends the reads/writes and modifies some addresses
so that it basically works.
It would be much better to use the modern Programmable Interrupt Timer
hardware module that these SoC contain. This PIT timer is used on all
the other modern ColdFire family members.
We also have DMA timer code that we will in the future use as a more
accurate clock source and cycle counter. So the idea here is to clean up
this usage to free up the timer hardware.
I don't have any 53xx based hardware, so I have not been able to run time
test this. If anyone can test this and confirm that it works as expected
that would be great.
Signed-off-by: Greg Ungerer <***@uclinux.org>
---
arch/m68k/Kconfig.cpu | 2 ++
arch/m68k/include/asm/m53xxsim.h | 19 ++++++++++---------
arch/m68k/include/asm/mcftimer.h | 4 ----
arch/m68k/platform/coldfire/Makefile | 2 +-
arch/m68k/platform/coldfire/timers.c | 16 ++--------------
5 files changed, 15 insertions(+), 28 deletions(-)