Re: [Linaro-mm-sig] [PATCH 1/1] dt: Add general DMA window parser

* Hiroshi Doyu wrote:

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