On Fri, Dec 19, 2014 at 01:32:37AM +0300, Antony Pavlov wrote: > The commit > > commit 0d7a21334536cb36b3c9b64d868acc55aec41332 > Author: Antony Pavlov <antonynpavlov@xxxxxxxxx> > Date: Wed Sep 10 11:42:19 2014 +0400 > > MIPS: dts: use physical addresses (as Linux does) > > With IOMEM() adapted for MIPS we can use physical addresses > in device tree reg property. > > is premature. Current device tree files unusable on real hardware. > I'M SO SORRY! > The patch was tested on qemu, but qemu malta board is tolerant > of using physical addresses for accesing to device. Real hardware > can throw an exception in this situation. > > Additional physical address to virtual address translation on MIPS is needed. > > This commit demonstrate a possible (but not very good) solution. > This solution is copied-and-pasted from linux kernel. > In linux drivers use devm_ioremap_resource() function, so > the patch just replicates similar dev_ioremap_resource() function. > > Changing dev_request_mem_region() to dev_ioremap_resource() > is not a very good idea because there are too many dev_request_mem_region() > in barebox sources > > barebox$ git grep dev_request_mem_region | wc -l > 197 > > moreover dev_ioremap_resource() has the second 'struct resource *res' > argument, so additional dev_get_resource() is needed. > > Can we insert ioremap() into dev_request_mem_region() directly? > (we also can use already existion IOMEM() macro instead of linux' ioremap()). I'm not sure if it's a good idea to put that behind some standard lookingioremap() call, because its behaviour is not standard. I'm also fine with adding some #ifdef CONFIG_MIPS return mips_iomem(res->start); #else return (void __force __iomem *)res->start; #endif At least this makes explicit that MIPS has a very special handling. Sascha -- Pengutronix e.K. | | Industrial Linux Solutions | http://www.pengutronix.de/ | Peiner Str. 6-8, 31137 Hildesheim, Germany | Phone: +49-5121-206917-0 | Amtsgericht Hildesheim, HRA 2686 | Fax: +49-5121-206917-5555 | _______________________________________________ barebox mailing list barebox@xxxxxxxxxxxxxxxxxxx http://lists.infradead.org/mailman/listinfo/barebox
