[U-Boot] [PATCH v4 2/2] arc: use timer driver instead of arch/arc/lib/timer.c

[Alexey Brodkin]

Hi Vlad,

On Tue, 2016-11-22 at 18:54 +0300, Vlad Zakharov wrote:
> This commit replaces legacy timer code with usage of arc timer
> driver.
> 
> Also it adds timer0 device tree node with corresponding
> "clock-frequency" property.
> 
> Therefore we remove legacy CONFIG_SYS_TIMER_RATE config symbol
> that is not longer required.
> 
> Furthermore the commit selects CONFIG_TIMER and CONFIG_ARC_TIMER
> by default when selecting ARC architecture.
> 
> Signed-off-by: Vlad Zakharov <vzakhar at synopsys.com>
> Reviewed-by: Simon Glass <sjg at chromium.org>
> ---
> Changes v3..v4:
>  - Remove CONFIG_SYS_TIMER_RATE not only from "axs10x.h" but also
> from "nsim.h" and "tb100.h".
> 
>  arch/Kconfig               |  2 ++
>  arch/arc/dts/skeleton.dtsi |  6 ++++++
>  arch/arc/lib/Makefile      |  1 -
>  arch/arc/lib/timer.c       | 24 ------------------------
>  include/configs/axs10x.h   |  2 --
>  include/configs/nsim.h     |  5 -----
>  include/configs/tb100.h    |  5 -----
>  7 files changed, 8 insertions(+), 37 deletions(-)
>  delete mode 100644 arch/arc/lib/timer.c
> 
> diff --git a/arch/Kconfig b/arch/Kconfig
> index ffc7b45..56fa70e 100644
> --- a/arch/Kconfig
> +++ b/arch/Kconfig
> @@ -12,6 +12,8 @@ config ARC
>  	bool "ARC architecture"
>  	select HAVE_PRIVATE_LIBGCC
>  	select SUPPORT_OF_CONTROL
> +	select TIMER
> +	select ARC_TIMER
>  
>  config ARM
>  	bool "ARM architecture"
> diff --git a/arch/arc/dts/skeleton.dtsi b/arch/arc/dts/skeleton.dtsi
> index b41d241..3e93d697 100644
> --- a/arch/arc/dts/skeleton.dtsi
> +++ b/arch/arc/dts/skeleton.dtsi
> @@ -10,4 +10,10 @@
>  	chosen { };
>  	aliases { };
>  	memory { device_type = "memory"; reg = <0 0>; };
> +
> +	timer at 0 {
> +			compatible = "snps,arc-timer";
> +			clock-frequency = <100000000>;
> +			reg = <0>;
> +	};

I've just realized that with timer clock hard-coded for now
we need to duplicate timer entry for each and every ARC board
because they all are clocked by differently.

For example axs101 runs @700 MHz and so its timer increment with
the same speed but axs103 runs @100 MHz and its timer runs at the same
100 MHz speed.

I think with your next change http://patchwork.ozlabs.org/patch/696870/
we'll be able to move timer node in common skeleton i instead of hardcoded
clock value we'll refer to clk phandle and clk phandle will be specified per
board.

I.e. this series should be respinned again I thin, sorry for catching that
issue a bit too late.

-Alexey