misc: sram: add optional ioremap without write combining (eb43e023) · Commits · 戴 / test

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 <mw@semihalf.com> Signed-off-by:

David S. Miller <davem@davemloft.net>

Documentation/devicetree/bindings/sram/sram.txt

+5 −0

Original line number	Diff line number	Diff line
		@@ -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

drivers/misc/sram.c

+4 −1

Original line number	Diff line number	Diff line
		@@ -360,6 +360,9 @@ static int sram_probe(struct platform_device *pdev)
		return -EBUSY;
		}

		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);

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