[PATCH 1/2] ARM: EXYNOS: Map SYSRAM through generic SRAM bindings

[Sachin Kamat]

Hi Heiko,

On 1 May 2014 18:57, Heiko Stübner <heiko at sntech.de> wrote:
> Hi Sachin,
>
> Am Donnerstag, 1. Mai 2014, 16:14:44 schrieb Sachin Kamat:
>> Instead of hardcoding the SYSRAM details for each SoC,
>> pass this information through device tree (DT) and make
>> the code SoC agnostic. Generic SRAM bindings are used
>> for achieving this.
>>
>> Signed-off-by: Sachin Kamat <sachin.kamat at linaro.org>
>> Cc: Heiko Stuebner <heiko at sntech.de>
>> Cc: Arnd Bergmann <arnd at arndb.de>
>
> very cool :-).

Thanks :)

>
> I've found one little thing I do not understand, which I describe below.
> Otherwise
> Acked-by: Heiko Stuebner <heiko at sntech.de>
>
>> ---
>> This patch is based on linux next (next-20140501) on top of
>> my Kconfig consolidation patch
>> http://comments.gmane.org/gmane.linux.kernel.samsung-soc/28642
>>
>> Tested on 4210/4412 Origen, 5250/5420 Arndale and SMDK5420 boards.
>> ---
>>  arch/arm/Kconfig                                |    1 +
>>  arch/arm/boot/dts/exynos4210-universal_c210.dts |   17 ++++++
>>  arch/arm/boot/dts/exynos4210.dtsi               |   18 +++++++
>>  arch/arm/boot/dts/exynos4x12.dtsi               |   18 +++++++
>>  arch/arm/boot/dts/exynos5250.dtsi               |   18 +++++++
>>  arch/arm/boot/dts/exynos5420.dtsi               |   18 +++++++
>>  arch/arm/mach-exynos/common.h                   |    1 +
>>  arch/arm/mach-exynos/exynos.c                   |   64
>> ----------------------- arch/arm/mach-exynos/firmware.c                 |
>>  5 +-
>>  arch/arm/mach-exynos/include/mach/map.h         |    7 ---
>>  arch/arm/mach-exynos/platsmp.c                  |   39 +++++++++++++-
>>  11 files changed, 133 insertions(+), 73 deletions(-)
>>
>> diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
>> index a6aaaad19b1a..f66ea9453df9 100644
>> --- a/arch/arm/Kconfig
>> +++ b/arch/arm/Kconfig
>> @@ -855,6 +855,7 @@ config ARCH_EXYNOS
>>       select S5P_DEV_MFC
>>       select SAMSUNG_DMADEV
>>       select SPARSE_IRQ
>> +     select SRAM
>>       select USE_OF
>>       help
>>         Support for SAMSUNG's EXYNOS SoCs (EXYNOS4/5)
>> diff --git a/arch/arm/boot/dts/exynos4210-universal_c210.dts
>> b/arch/arm/boot/dts/exynos4210-universal_c210.dts index
>> 63e34b24b04f..8d4de5c0d0c7 100644
>> --- a/arch/arm/boot/dts/exynos4210-universal_c210.dts
>> +++ b/arch/arm/boot/dts/exynos4210-universal_c210.dts
>> @@ -28,6 +28,23 @@
>>               bootargs = "console=ttySAC2,115200N8 root=/dev/mmcblk0p5 rw rootwait
>> earlyprintk panic=5 maxcpus=1"; };
>>
>> +     sram at 02020000 {
>> +             status = "disabled";
>> +     };
>> +
>> +     sram at 02025000 {
>> +             compatible = "mmio-sram";
>> +             reg = <0x02025000 0x1000>;
>> +             #address-cells = <1>;
>> +             #size-cells = <1>;
>> +             ranges = <0 0x02025000 0x1000>;
>> +
>> +             smp-sram at 0 {
>> +                     compatible = "samsung,exynos4210-sram";
>> +                     reg = <0x0 0x1000>;
>> +             };
>> +     };
>
> exynos_smp_prepare_sram returns -ENODEV if it can't find
> samsung,exynos4210-sram-ns, so are you sure your universal_c210 will run
> without it? I didn't dig to deep into this, so it can also simply be something
> I overlooked :-)

Actually I do not have a universal_c210 board and hence could not
check on it and
thus this point got overlooked. Thanks for spotting it and you are
right. There shouldn't
be a error return if second node is not present as it is optional. I
will modify accordingly
and send this patch again. Thanks for your review and Ack :)

-- 
With warm regards,
Sachin