Hi Olof,
On Wednesday 10 of October 2012 09:00:27 Olof Johansson wrote:
> Hi,
>
> On Mon, Sep 24, 2012 at 04:28:32PM +0200, Tomasz Figa wrote:
> > Some Exynos-based boards contain secure firmware and must use firmware
> > operations to set up some hardware.
> >
> > This patch adds firmware operations for Exynos secure firmware and a
> > way
> > for board code and device tree to specify that they must be used.
> >
> > Example of use:
> >
> > In board code:
> > ...MACHINE_START(...)
> >
> > /* ... */
> > .init_early = exynos_firmware_init,
> > /* ... */
> >
> > MACHINE_END
> >
> > In device tree:
> > / {
> >
> > /* ... */
> >
> > firmware {
> >
> > compatible = "samsung,secure-firmware";
> >
> > };
> >
> > /* ... */
> >
> > };
> >
> > Signed-off-by: Kyungmin Park <kyungmin.park@xxxxxxxxxxx>
> > Signed-off-by: Tomasz Figa <t.figa@xxxxxxxxxxx>
> > ---
> >
> > .../devicetree/bindings/arm/samsung-boards.txt | 8 ++++
> > arch/arm/mach-exynos/Makefile | 1 +
> > arch/arm/mach-exynos/common.h | 2 +
> > arch/arm/mach-exynos/firmware.c | 54
> > ++++++++++++++++++++++ arch/arm/mach-exynos/mach-exynos4-dt.c
> > | 1 +
> > 5 files changed, 66 insertions(+)
> > create mode 100644 arch/arm/mach-exynos/firmware.c
> >
> > diff --git a/Documentation/devicetree/bindings/arm/samsung-boards.txt
> > b/Documentation/devicetree/bindings/arm/samsung-boards.txt index
> > 0bf68be..f447059 100644
> > --- a/Documentation/devicetree/bindings/arm/samsung-boards.txt
> > +++ b/Documentation/devicetree/bindings/arm/samsung-boards.txt
> >
> > @@ -6,3 +6,11 @@ Required root node properties:
> > - compatible = should be one or more of the following.
> >
> > (a) "samsung,smdkv310" - for Samsung's SMDKV310 eval board.
> > (b) "samsung,exynos4210" - for boards based on Exynos4210
> > SoC.
> >
> > +
> > +Optional:
> > + - firmware node, specifying presence and type of secure firmware,
> > currently + supported value of compatible property is
> > "samsung,secure-firmware": +
> > + firmware {
> > + compatible = "samsung,secure-firmware";
> > + };
>
> If you require the binding to specify the memory area, then you at least
> allow for future work to move to a dynamic mapping without updating the
> binding and all device trees. So, please do that even if the code is
> hardcoded to the static address today.
All right.
> For extra credit, make sure that the reg property is matching the static
> mapping when you setup your firmware interface on your platform.
Hmm, do you know a way to look up physical address of such static mapping,
given only the virtual address? Additional problem is that the code is
executed very early (in init_early callback), before most of VM
initialization code.
I could do something like
if (soc_is_exynos4210())
paddr = EXYNOS4210_PA_SYSRAM_NS;
else if (soc_is_exynos4212() || soc_is_exynos4412())
paddr = EXYNOS4x12_PA_SYSRAM_NS;
...
and compare paddr with address received from device tree, but I don't
really like this construct.
> > +static int exynos_cpu_boot_reg(int cpu, void __iomem **ptr)
> > +{
> > + *ptr = S5P_VA_SYSRAM_NS + 0x1c + 4*cpu;
> > + return 0;
> > +}
>
> It would be nice to get a memory map for the SMC area in documentation
> somewhere, but that can be done separately later.
OK.
Best regards,
--
Tomasz Figa
Samsung Poland R&D Center
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