Hi Arnd, I forgot to add you in CC for this patch. What is your opinion about it?
Gregory On lun., mars 14 2016, Gregory CLEMENT <gregory.clem...@free-electrons.com> wrote: > From: Marcin Wojtas <m...@semihalf.com> > > Some SRAM users may require non-bufferable access to the memory, which is > impossible, because devm_ioremap_wc() is used for setting sram->virt_base. > > This commit adds optional flag 'no-memory-wc', which allow to choose remap > method, using DT property. Documentation is updated accordingly. > > Signed-off-by: Marcin Wojtas <m...@semihalf.com> > --- > Documentation/devicetree/bindings/sram/sram.txt | 5 +++++ > drivers/misc/sram.c | 5 ++++- > 2 files changed, 9 insertions(+), 1 deletion(-) > > diff --git a/Documentation/devicetree/bindings/sram/sram.txt > b/Documentation/devicetree/bindings/sram/sram.txt > index 42ee9438b771..227e3a341af1 100644 > --- a/Documentation/devicetree/bindings/sram/sram.txt > +++ b/Documentation/devicetree/bindings/sram/sram.txt > @@ -25,6 +25,11 @@ Required properties in the sram node: > - ranges : standard definition, should translate from local addresses > within the sram to bus addresses > > +Optional properties in the sram node: > + > +- no-memory-wc : the flag indicating, that SRAM memory region has not to > + be remapped as write combining. WC is used by default. > + > Required properties in the area nodes: > > - reg : iomem address range, relative to the SRAM range > diff --git a/drivers/misc/sram.c b/drivers/misc/sram.c > index 736dae715dbf..69cdabea9c03 100644 > --- a/drivers/misc/sram.c > +++ b/drivers/misc/sram.c > @@ -360,7 +360,10 @@ static int sram_probe(struct platform_device *pdev) > return -EBUSY; > } > > - sram->virt_base = devm_ioremap_wc(sram->dev, res->start, size); > + if (of_property_read_bool(pdev->dev.of_node, "no-memory-wc")) > + sram->virt_base = devm_ioremap(sram->dev, res->start, size); > + else > + sram->virt_base = devm_ioremap_wc(sram->dev, res->start, size); > if (IS_ERR(sram->virt_base)) > return PTR_ERR(sram->virt_base); > > -- > 2.5.0 > -- Gregory Clement, Free Electrons Kernel, drivers, real-time and embedded Linux development, consulting, training and support. http://free-electrons.com
