From eb43e023130b5021c1ffad4d5c84cb310ffcb0f6 Mon Sep 17 00:00:00 2001 From: Marcin Wojtas Date: Mon, 14 Mar 2016 09:38:56 +0100 Subject: [PATCH] misc: sram: add optional ioremap without write combining 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 Signed-off-by: David S. Miller --- 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 42ee943..227e3a3 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 736dae7..69cdabe 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); -- 2.7.4