Re: [PATCH 1/1] dt: Add general DMA window parser
From: Thierry Reding <hidden>
Date: 2012-04-18 10:54:23
Also in:
linux-arm-kernel, linux-iommu, linux-tegra
* Hiroshi Doyu wrote:
quoted hunk
diff --git a/drivers/of/of_dma.c b/drivers/of/of_dma.c new file mode 100644 index 0000000..45c9e88 --- /dev/null +++ b/drivers/of/of_dma.c@@ -0,0 +1,35 @@ +/* + * Stolen from: + * "arch/microblaze/kernel/prom_parse.c" + * "arch/powerpc/kernel/prom_parse.c" + */ + +#include <linux/of_address.h> + +void of_parse_dma_window(struct device_node *dn, const void *dma_window_prop, + unsigned long *busno, unsigned long *phys, unsigned long *size) +{ + const __be32 *dma_window; + u32 cells; + const unsigned char *prop;
There's no need for this to be const unsigned char *, const void * will do just as well.
+ + dma_window = dma_window_prop; + + /* busno is always one cell */ + if (busno) + *busno = be32_to_cpup(dma_window++); + + prop = of_get_property(dn, "#dma-address-cells", NULL); + if (!prop) + prop = of_get_property(dn, "#address-cells", NULL); + + cells = prop ? be32_to_cpup(prop) : of_n_addr_cells(dn); + *phys = of_read_number(dma_window, cells);
This should probably fail gracefully if phys == NULL, similar to what you do for busno.
+ + dma_window += cells; + + prop = of_get_property(dn, "#dma-size-cells", NULL); + cells = prop ? be32_to_cpup(prop) : of_n_size_cells(dn); + *size = of_read_number(dma_window, cells);
Same here.
+} +
And you might want to add a EXPORT_SYMBOL(of_parse_dma_window) here so the function can be used from modules. Sorry for having you go through another round. I should have looked more closely before. Thierry
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