[PATCH 0/9] ARM: dts: Various OMAP2+ device-tree updates
Jon Hunter
jon-hunter at ti.com
Thu Mar 14 12:04:49 EDT 2013
On 03/14/2013 11:02 AM, Javier Martinez Canillas wrote:
> On Thu, Mar 14, 2013 at 3:57 PM, Benoit Cousson <b-cousson at ti.com> wrote:
>> Salut Jon,
>>
>> On 03/08/2013 06:27 PM, Jon Hunter wrote:
>>> Various OMAP device-tree updates for PMU, DMA, GPIO, GPMC and boards.
>>>
>>> The DMA, PMU and OMAP3430 SDP board changes have been sent before
>>> individually but re-sending here as a complete series for v3.10.
>>>
>>> This is based upon v3.9-rc1 and the OMAP3 GPMC binding from Florian
>>> Vaussard [1] and OMAP5 DT SPI patch from Felipe Balbi [2].
>>>
>>> [1] https://patchwork.kernel.org/patch/2057111/
>>
>> I've tried to follow the series review, and it seems that Florian was
>> considering sending some other patches. It is not clear if this is a new
>> version of the series or some additional patches.
>>
>
> Hi Benoit,
>
> According to [1] Jon suggested that it was not necessary to map all
> the 16MB for the GPMC mapped register address space since in practice
> is a very small fraction of that size is used.
>
> I had the following patch but I did never post it because Jon said
> that the I/O memory mapping is page-aligned and the minimum page
> size for ARM is 4KB anyways, so there is no functional difference
> between using 0x1000 or 0x02d0.
>
> But now reading [2] I see that you prefer to do what the documentation
> said and don't assume any the page size / alignment.
>
> [2]: https://patchwork.kernel.org/patch/2239741/
>
> From 68edff5a102bb8fc81e006738baa456eb69f080a Mon Sep 17 00:00:00 2001
> From: Javier Martinez Canillas <javier.martinez at collabora.co.uk>
> Date: Wed, 27 Feb 2013 02:30:51 +0100
> Subject: [PATCH] ARM: dts: OMAP3: reduce GPMC mapped registers address space
>
> Currently the OMAP General-Purpose Memory Controller (GPMC) device
> node maps 16 MB of address space for its hardware registers.
>
> This is because the OMAP Technical Reference Manual says that the
> GPMC module register address space size is 16 MB. But in practice
> the maximum address offset used by a GPMC register is 0x02d0.
>
> So, there is no need to map such a big address space for GPMC regs.
>
> This change was suggested by Jon Hunter [1].
>
> [1]: https://patchwork.kernel.org/patch/2057111/
>
> Signed-off-by: Javier Martinez Canillas <javier.martinez at collabora.co.uk>
> ---
> arch/arm/boot/dts/omap3.dtsi | 2 +-
> 1 files changed, 1 insertions(+), 1 deletions(-)
>
> diff --git a/arch/arm/boot/dts/omap3.dtsi b/arch/arm/boot/dts/omap3.dtsi
> index 2ddae38..a60eaf1 100644
> --- a/arch/arm/boot/dts/omap3.dtsi
> +++ b/arch/arm/boot/dts/omap3.dtsi
> @@ -407,7 +407,7 @@
> gpmc: gpmc at 6e000000 {
> compatible = "ti,omap3430-gpmc";
> ti,hwmods = "gpmc";
> - reg = <0x6e000000 0x1000000>;
> + reg = <0x6e000000 0x02d0>;
> interrupts = <20>;
> gpmc,num-cs = <8>;
> gpmc,num-waitpins = <4>;
>
Thanks!
Acked-by: Jon Hunter <jon-hunter at ti.com>
Cheers
Jon
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