On Wed, Aug 31, 2011 at 1:05 PM, Sebastian Andrzej Siewior <bige...@linutronix.de> wrote: > * Pratyush Anand | 2011-08-30 17:28:01 [+0530]: > >>diff --git a/arch/arm/include/asm/io.h b/arch/arm/include/asm/io.h >>index 815efa2..32282b4 100644 >>--- a/arch/arm/include/asm/io.h >>+++ b/arch/arm/include/asm/io.h >>@@ -297,6 +297,14 @@ extern int valid_mmap_phys_addr_range(unsigned long pfn, >>size_t size); >> extern int devmem_is_allowed(unsigned long pfn); >> #endif >> >>+/* Big Endian */ >>+#define out_be32(a, v) writel(__cpu_to_be32(v), a) >>+#define in_be32(a) __be32_to_cpu(readl(a)) >>+ >>+/* Little endian */ >>+#define out_le32(a, v) writel(__cpu_to_le32(v), a) >>+#define in_le32(a) __le32_to_cpu(readl(a)) > > In LE-mode __le32_to_cpu() is NOP and you get a LE value. > In BE-mode readl() will swap a and le32_to_cpu will swap a again. So you > get a BE value. Is this what you want? >
There can be some peripheral like dwc-otg, whose registers will be either in LE or in BE depending on the RTL configuration selected by a implementor. Software always expects a LE value when it will call "in_" and will provide a LE value when "out_". It expects beacuse , it wants to do same bit wise operation for both configurations. >>+ > > Please split this patch out and get it accepterd by ARM community. USB > people won't merge this. > Ok, will send it to ARM mailing list. Regards Pratyush > Sebastian > -- > To unsubscribe from this list: send the line "unsubscribe linux-usb" in > the body of a message to majord...@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html > _______________________________________________ Linuxppc-dev mailing list Linuxppc-dev@lists.ozlabs.org https://lists.ozlabs.org/listinfo/linuxppc-dev
